JP2008017611A - In-vehicle motor drive unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an in-vehicle motor drive unit to drive a driven portion by a motor by which the durability and reliability of the unit are improved by reducing the heat generation of the motor and its drive circuit, while favorably keeping the drive responsiveness of the driven portion without requiring an angle sensor or a position sensor of the driven portion. <P>SOLUTION: In a system which drives the opening/closing of a valve by the motor, the motor is energized at 100% of a duty when totally opening the valve. An energizing current is suppressed to some extent by counter electromotive force during the rotation of the motor, but when the valve is totally opened, its drive is stopped, and the motor is locked, the energizing current sharply rises. Also in such a case, energization at 100% of a duty is continued without limiting the energizing current. When the energizing current becomes an opening/closing-completed current threshold or larger, the completion of the drive of the valve (totally opened) is detected, and a microcomputer outputs a drive command (a low-level signal) to instruct to that the energization of the motor should be stopped, by which the energization of the motor is quickly stopped. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a vehicle-mounted motor drive device that is mounted on a vehicle and configured such that a driven part is driven by a motor.

  Conventionally, for example, as shown in FIG. 16 (a), one of the two intake ports (details will be described later, see FIG. 1) provided in an automobile internal combustion engine for opening and closing one first intake port 5a. When a swirl control valve (hereinafter abbreviated as “SCV”) 10 is energized and driven by a motor (not shown), generally, the rotational driving force of the motor is applied to the rotating shaft 20 of the SCV 10 via a reduction gear or the like. A system that communicates is configured. The SCV 10 is driven either in a state where the first intake port 5a shown on the left side of FIG. 16A is fully closed or in a state where the first intake port 5a shown on the right side of FIG. 16A is fully opened. Is done. Therefore, the operating range of the SCV 10 is limited to the range from the fully closed state (closed position) to the fully open state (open position).

  That is, as shown in FIG. 16 (a), when the SCV 10 is in the fully closed state (the state on the left side of FIG. 16 (a)), the microcomputer (not shown) that controls the motor transfers to the drive circuit (not shown). When the drive circuit starts energizing the motor in response to the opening command, the motor rotates and the rotational driving force is transmitted to the SCV 10 via a reduction gear or the like. Therefore, the SCV 10 starts to open by rotating around the rotating shaft 20 (the state in the center of FIG. 16A). When the SCV 10 reaches the fully open state (the state on the right side of FIG. 16A), the SCV 10 contacts the inner wall of the first intake port 5a and does not move any further. As a result, the rotation is stopped even when the motor is continuously energized. This state is also called a locked state. While the motor is rotating, the energization current is suppressed due to the counter electromotive force generated by the rotation, but when the motor is locked, the rotation of the motor is forcibly stopped. Suddenly rises and an excessive current (hereinafter also referred to as “lock current”) flows.

  Even when the SCV 10 is driven from the fully open state to the fully closed state, the SCV 10 gradually approaches the closed position by energization of the motor, and eventually the end of the SCV 10 is provided on the inner wall of the first intake port 5a. It abuts against the regulated protrusion 21. Thereby, SCV10 will be in a fully closed state and will not move any more. Again, the motor is locked and a lock current flows.

  Applying a lock current to the motor for a long time can be said to be a meaningless operation from the original purpose of opening and closing the SCV 10 by rotating the motor to a predetermined position. Further, if the lock current flows for a long time, the motor and its drive circuit may generate heat and exceed the maximum rating. Thus, the following three methods are conceivable as methods for preventing the ratings from being exceeded.

  The first method is to make the motor and its drive circuit resistant to heat generation. However, in this case, a semiconductor having a large chip size must be used in the drive circuit in order to reduce the conduction resistance, so that the semiconductor becomes expensive. Alternatively, it is necessary to use a motor or a drive circuit having a large structure with high heat dissipation that can withstand excessive heat generation. Therefore, it is disadvantageous in terms of cost and is not realistic.

  The second method is to provide an angle sensor in the SCV 10 and stop or reduce energization when a predetermined opening (opening or opening) is reached. By providing the angle sensor in this way, it is possible to reduce the heat generation of the drive circuit, and the drive circuit can be kept to the minimum necessary size. However, since it is necessary to provide an angle sensor, the cost is naturally increased accordingly, and the entire system becomes expensive.

  The third method is to set the upper limit value of the energization current and limit the current to not exceed it. When the state where the energization current reaches the upper limit value continues for a certain period of time, Is a method of determining that the lock has occurred (see, for example, Patent Document 1).

  That is, after the energization current reaches the upper limit value, it does not matter whether the SCV 10 is fully opened or closed, but it is energized at the upper limit value for a sufficient period of time when it is considered to be fully open or fully closed (ie, the motor is locked). If the operation continues, it is determined that the motor is locked, that is, the SCV 10 is fully closed or fully opened. In this method, the determination of full open or full close is made based solely on the energization current and the energization time, and the angle sensor for detecting the open / close state is not used for cost reduction. With this method, it is possible to reduce the size of the drive circuit while securing the opening / closing operation of the SCV 10, and it is the most advantageous in terms of cost as compared with the first and second methods.

  Specifically, based on FIG. 17, when the open command indicating that the SCV 10 should be opened is output from the microcomputer when the SCV 10 is in the closed state, the drive circuit energizes the motor in response to the open command. To start. At this time, the motor is energized at DUTY 100%, and an inrush current flows immediately after the start of rotation, but a current corresponding to the rotation speed flows during the subsequent rotation. Therefore, the temperature rise of the drive circuit is small.

  During this time, the SCV 10 gradually opens. However, when the SCV 10 reaches the open position and becomes fully open, the SCV 10 contacts the inner wall of the first intake port 5a as described above, and the rotation of the motor is forcibly stopped (locked). ). As a result, the energization current increases rapidly, but when the current limit value is reached, the increase in current is limited there.

  This current limitation is performed by the self-protection function of the drive circuit itself. That is, when the current limit value reaches the current limit value until the current limit value is reached, the current is switched to the current supply (duty drive) with a duty ratio less than 100% so as not to exceed the current limit value.

  In FIG. 17, the case where the energization current of the motor is lower than the current limit value during the opening operation of the SCV 10 and exceeds the current limit value when the motor is locked by being fully opened is described. Depending on the state, the energization current of the motor may reach the current limit value even during the opening operation as shown in FIG. Therefore, when the state limited to the current limit value continues for the lock determination time T1, it is assumed that the motor is locked, that is, the SCV 10 is fully opened, and the open command output from the microcomputer is stopped and the motor is energized. I try to stop it.

In other words, since the angle sensor is not provided, it is not directly known that the valve is fully opened or fully closed, but the SCV 10 is surely opened and closed by energizing the motor for a sufficiently long time to be fully opened or fully closed. This method is also called “butting control”.
Japanese Patent No. 3458753

  However, in the above-described abutting control, it is necessary to set a sufficiently long time that will be fully opened or fully closed as the lock determination time T1, and thus energization with the limited current value continues for a long time. Therefore, as shown in FIG. 17, the temperature of the drive circuit and the motor rises from when the motor is locked until the energization is stopped. In addition, if the energization is repeated before the increased temperature returns to the original level (the level before the energization is started), the temperature of the drive circuit and the motor will continue to rise. .

  This temperature rise is naturally not preferable for the motor and its drive circuit. For this reason, it is desirable to set the lock determination time T1 as short as possible so that the temperature does not rise excessively.

  However, since the SCV 10 is a valve used in an intake system of an internal combustion engine, deposits accumulate with long-term use, and the rotational speed (opening / closing speed) also decreases with the passage of years of use. Therefore, the lock determination time T1 needs to be set sufficiently long assuming the state of the SCV 10 after durability so that the lock determination time T1 can be surely fully closed or fully opened even after long-term use (after durability).

  In other words, any system that has been in use for a long time may cause dust, moisture, oil, etc. floating in the intake port (intake pipe) to accumulate in the opening and closing parts of the valve, etc. It is generally known that it absorbs and oils and becomes viscous. The same applies to the SCV 10 described above. As shown in FIG. 16B, the deposit 23, which is a substance having such viscosity, adheres to the rotation shaft 20 of the SCV 10 and prevents the rotation of the SCV 10. It becomes viscous resistance. The viscosity resistance increases at a low temperature because it contains moisture, and in some cases, the resistance becomes very large. In order to rotate the SCV 10, it is necessary to complete the opening and closing by energizing with a large torque or for a long time. Further, although it depends on the use environment, the viscous resistance generally increases most at the end of the product life, that is, after durability.

  As the service life becomes longer, the viscous resistance due to deposit increases and the rotational speed of the motor also decreases. When the rotational speed of the motor is reduced in this way, the back electromotive force of the motor is also reduced, and even when the motor is rotating, the value of the energizing current rises to near the lock current. As shown in FIG. The value is reached. In other words, since the rotation speed is slow, the energization current increases immediately after the start of rotation, and the energization state with the current limit value is obtained even during rotation. Therefore, it is necessary to set the lock determination time T1 sufficiently long in consideration of the post-endurance deposit.

  However, in the initial state of the product, there is no (or almost no) deposit due to these viscous resistances, so the SCV 10 opens and closes smoothly and can be opened and closed in the shortest time. That is, in the case of endurance, the SCV 10 rotates at a low speed due to the adhesion of the deposit 23 as shown in FIG. 16B, but in the initial state, the SCV 10 has a high speed because there is no deposit as shown in FIG. It can be rotated. Nevertheless, since the lock determination time T1 is fixedly set to a long time in anticipation of endurance, energization with the upper limit current limit value continues for a long time, and heat generation of the motor and drive circuit increases. End up.

  As a specific example, for example, when the lock determination time T1 is set to 2 seconds in anticipation of the worst state after endurance, the viscosity resistance is large and the rotation speed is slow after endurance. The opening and closing is completed, and the lock current (current limit value) flows for the remaining 0.2 seconds. However, in the initial state, since there is no viscous resistance, the opening and closing are completed in about 0.1 seconds, and the remaining 1.9 For a second, the lock current (current limit value) continues to flow. Thus, if the lock current continues to flow for a long time despite the completion of opening and closing, the motor and its drive circuit generate a large amount of heat.

  In order to reduce the heat generation of the motor and the drive circuit, it is desirable to shorten the lock judgment time T1 as much as possible to shorten the energization time at the limit current value. In spite of not being opened or closed, there is a possibility that the lock determination time T1 elapses and erroneously determined to be fully closed or fully opened (particularly after endurance). Therefore, there is a limit to shortening the lock determination time T1, and as long as it needs to be set longer in anticipation of endurance, the closer to the initial state, the greater the amount of heat generated.

  Further, even after the endurance, the energization current reaches the current limit value from an early stage during rotation, and further increase in current is limited. Therefore, further increase in torque is limited even during rotation. That is, even after the endurance, the rotational speed is slow due to the deposit, and even though a larger rotational torque is required, a current limit is applied during the rotation and no further torque is applied. For this reason, a decrease in the motor rotation speed is further promoted, and the drive response of the SCV 10 is deteriorated.

  The present invention has been made in view of the above problems, and in an in-vehicle motor drive device that drives a driven part by a motor, the motor and its drive circuit generate heat while maintaining the drive response of the driven part well. It aims to reduce and improve the durability and reliability of the device.

  The invention according to claim 1, which has been made to solve the above problem, controls the driving of a driven part driven by a motor so as to be forcibly positioned at a predetermined position by an external factor. Motor drive device for driving a motor by energizing the motor based on an input drive command and a drive command for controlling the drive of the driven part to the drive unit A control means, a current detection means for detecting the energization current of the motor, and a current threshold set to a value for discriminating a lock flow flowing in the motor when the driven part is forcibly positioned by an external factor. A first threshold value setting unit set as a determination criterion for determining the drive completion of the driven part, and a current threshold value in which the energization current detected by the current detection unit is set in the first threshold value setting unit And a first drive completion determining means determines that the driving of the driven parts is completed when exceeded.

  In particular, the control means continuously energizes the motor from the start of driving of the driven part until at least the driving of the driven part is completed by being forcedly positioned by the external factor. Is output to the driving means. After the start of energization to the motor based on this continuous energization command (that is, after the drive of the driven part), when the first drive completion determination means determines that the drive of the driven part is completed, the drive means Stop or reduce power to the motor.

  In other words, when the driven part is driven by the motor, the current limit is set such that the upper limit value of the energization current is set and limited so as not to exceed the drive current until the drive is completed from the start of the drive. Without energizing, the motor is continuously energized. As a result, the maximum current that can be supplied by the driving means is supplied to the motor. However, the energization current is suppressed to some extent by the counter electromotive force of the motor itself while the motor is rotating (while the driven part is being driven). When the drive of the driven part is completed and the motor is in a locked state where the motor cannot rotate any more, the back electromotive force is lost and the energization current increases rapidly (see FIGS. 17 and 18 described above).

  Therefore, a predetermined current threshold value is set, and when this current threshold value is exceeded, it is determined that driving of the driven part is completed and the motor is also locked. Note that the current threshold value at this time is set to a value by which it can be determined whether or not it is a lock current that flows when the lock state is entered. Further, when it is determined that the driving is completed, the energization of the motor by the driving means is stopped or reduced.

  According to the vehicle-mounted motor drive device according to claim 1 configured as described above, the motor is continuously energized (without limiting energization as in the prior art) while the driven part is being driven. For this reason, the drive response of the driven part is improved. In addition, when the energization current exceeds the current threshold, that is, when it is determined that the drive of the driven part is completed, the energization to the motor is stopped or reduced, so that the lock current flows even after the drive is completed (after locking). Conventional problems are eliminated, and heat generation of the motor and driving means can be reduced. Moreover, since it is possible to determine whether or not the current threshold value is the lock current with the value, it is determined that the current limit value is reached and the lock is determined when the current has flowed for a predetermined time as in the prior art. The method can be detected more reliably and in a shorter time. Therefore, it is not necessary to separately provide a device such as the above-described angle sensor in order to determine whether the driven part is driven. Therefore, it is possible to improve the durability and reliability of the on-vehicle motor drive device while suppressing an increase in cost.

  The drive completion of the driven part means that the driven part is stopped by some external factor when it is driven to a predetermined state, and the motor can no longer rotate by this drive completion. . In other words, when the drive of the driven part is completed, the driven part does not move even if energization of the motor is continued to continue driving, and therefore the rotation of the motor is inevitably stopped (locked). . Therefore, in the following description, “locking” a motor means that the rotation of the motor is forcibly stopped upon completion of driving of the driven part, and that the motor is locked and driving of the driven part is completed. Is treated as a synonym.

  For example, the current threshold is a value that does not reach during motor rotation and that it reaches a sufficient value when the motor is locked and the energization current increases. A value that can be discriminated from an energization current value that flows when the motor rotates is set as appropriate for the completion of driving of the driving unit.

  Specifically, the stop or reduction of the energization of the motor by the drive unit based on the determination result of the drive completion by the first drive completion determination unit is specifically realized by, for example, the configuration according to claim 20 or 21 described later. However, the specific configuration is not particularly limited as long as the energization can be stopped or reduced as soon as possible after the completion of driving is determined.

  In addition, when the energization is reduced after the driving of the driven part is completed, it is possible to appropriately determine how much the power is reduced, for example, the driven part in the driving completed state is biased by a spring or the like and the motor If the energized power is stopped and the driven part returns to its original state due to the urging force, a current (holding current) that can counter the urging force is supplied to maintain the driving completion state. May be. In addition, for example, there is a case where there is a possibility that the actuator may move due to an external load (for example, pressure due to fluid) depending on the environment where the driven part is placed, although there is no bias by the spring as described above. The holding current may be supplied to such an extent that the driven portion does not move from the driving completion state even when the load is received.

  Conversely, once the drive is complete, the driven part may move, or the drive complete state is maintained even if the motor is de-energized although it is necessary to maintain the drive complete state. In such a case, energization of the motor may be completely stopped. In other words, whether the energization is stopped or reduced after the drive of the driven part is completed, or how much it is specifically reduced, depends on the overall configuration of the on-vehicle motor drive device and whether there is a load on the driven part. Further, it may be determined as appropriate in consideration of various conditions such as the surrounding environment and the necessity of maintaining the driving completion state.

  The on-vehicle motor drive device according to claim 1 is configured to determine the completion of driving of the driven portion when the energization current to the motor exceeds the current threshold, but the motor includes a commutator and the commutator. In the case of a DC motor with a brush having a brush that is in sliding contact with the child (hereinafter simply referred to as “DC motor”), for example, as described in claim 2, driving of the driven part is performed using the current-carrying characteristics unique to the DC motor. Completion can be determined. The current-carrying characteristic unique to a DC motor means that the commutator switching between the commutator until the next commutator contacts the brush while the commutator that is in contact with the brush moves away from the brush due to the rotation of the motor. There is a double contact period in which both of them are in contact with one brush, and during this double contact period, the energization current value increases compared to the other period (the period in which one commutator is in contact with one brush). That is.

  As a result, during the motor rotation, the energization current becomes a ripple current including a ripple. On the contrary, when the motor rotation is stopped, this ripple naturally does not occur. Therefore, if the presence or absence of this ripple is detected, it can be determined whether or not the motor is rotating, and thus whether or not driving of the driven part is completed.

  That is, the in-vehicle motor drive device according to claim 2 is the same as that of claim 1 in that it includes a driven part, drive means, control means, and current detection means. It is a motor (DC motor) which has a brush in sliding contact with the commutator and is driven by a DC power source supplied from the outside through this brush.

  Furthermore, a second threshold setting unit in which a ripple cycle threshold is set as a criterion for determining completion of driving of the driven unit, and a cycle of the ripple included in the energization current detected by the current detection unit is the second. Second drive completion determination means for determining that driving of the driven part is completed when the ripple cycle threshold set in the threshold setting means is exceeded.

  The drive means energizes the motor when the second drive completion judging means determines that the drive of the driven part is completed after the start of energization of the motor based on the continuous energization command from the control means. Stop or reduce.

  That is, in the case of a DC motor, as long as the motor is rotating, ripples are generated at a period corresponding to the rotation speed. However, when the rotation is stopped, ripples are not generated thereafter. Therefore, the ripple cycle threshold is set appropriately, and when the ripple cycle becomes larger than this ripple cycle threshold (in other words, the next ripple is detected even if the ripple cycle threshold elapses after the previous ripple was detected. If not, the drive of the driven part is stopped and the motor is also determined to have stopped rotating (locked). After this determination, as in the first aspect, the energization current to the motor is stopped or reduced.

  Even with the on-vehicle motor drive device according to claim 2 configured as described above, the motor is continuously energized (without energization restriction as in the prior art) while the driven part is being driven. As a result, the drive response of the driven part is improved. In addition, when the ripple period exceeds the ripple period threshold value, that is, when it is determined that driving of the driven part is completed, the energization to the motor is stopped or reduced. The conventional problem of flowing can be solved, and the heat generation of the motor and driving means can be reduced. Therefore, as in the first aspect, it is possible to improve durability and reliability of the in-vehicle motor drive device while suppressing an increase in cost.

  In the in-vehicle motor drive device according to the second aspect, the determination of the completion of driving of the driven part by the second drive completion determination means can be more specifically realized by the configuration according to the third aspect, for example. . That is, a direct current component removing unit that removes a direct current component from the energization current detected by the current detecting unit, a third threshold setting unit in which a ripple detection threshold is set as a criterion for determining the occurrence of ripple, A ripple generation determination unit that determines that a ripple has occurred when the energization current after the DC component removal by the DC component removal unit exceeds the ripple detection threshold set in the third threshold setting unit, and the ripple generation determination unit Measurement means for measuring the elapsed time after the determination as a ripple period each time it is determined that a ripple has occurred. Then, the second drive completion determination unit determines that the drive of the driven unit is completed when the elapsed time measured by the measurement unit exceeds the ripple cycle threshold.

  By configuring the in-vehicle motor drive device as described above, it is possible to reliably detect the ripple and measure the ripple period based on it, and reliably determine the completion of driving of the driven part based on the measurement result. be able to.

  The ripple generation determination unit may determine the occurrence of ripple using the energization current itself after the DC component removal by the DC component removal unit, but the ripple component contained in the energization current when the DC motor rotates. Is generally a minute value. For this reason, the occurrence of ripple may be determined by amplifying the energized current after removal of the DC component at an appropriate amplification factor and setting a ripple detection threshold based on the energized current after the amplification.

  The in-vehicle motor drive device configured to determine the completion of driving of the driven part based on the ripple of the energization current as described in claim 2 or 3, further includes an energization current as described in claim 4, for example. It can also be configured to have means for determining the completion of driving of the driven part based on the value (that is, the configuration described in claim 1).

  That is, the vehicle-mounted motor drive device according to claim 2 or 3 further includes a first threshold value setting unit in which a current threshold value is set and a first drive completion determination unit as in the case of claim 1. Then, a determination to select either the determination result by the first drive completion determination unit or the determination result by the second drive completion determination unit as a determination criterion for the timing at which the energization of the motor by the driving unit is stopped or reduced When the driving completion of the driven portion is determined by any of the driving completion determining means selected by the determination selecting means, the energization of the motor by the driving means is stopped or reduced.

  According to the on-vehicle motor drive apparatus configured as described above, the drive completion determination means for determining the drive completion of the driven part is provided, and the drive completion is determined by one of the two units. The degree of freedom of selection of the determination method is expanded.

  As to which of the above two driving completion determination means is selected by the determination selection means, for example, it is usually fixed to one of them and switched to the other when it does not operate normally. The selection method and selection criteria can be considered variously, such as a method can be taken, but depending on the state of the motor and driven part, it is also possible to select the one that can determine the completion of driving more reliably Is possible.

  In other words, in the case of an initial product in which the driven part is in an initial state (new state just manufactured), there is usually no factor (less) that hinders the driving of the driven part, such as the deposit described above. Since the rotation is fast, the double contact period of the commutator is short and the ripple is also small. Therefore, the higher the rotation speed, the more difficult it is to detect ripples (determination of ripple generation by the ripple generation determination means). On the other hand, with respect to the energization current value, the rotation speed is fast in the case of the initial product. Then, when the drive of the driven part is completed and the motor is locked, the energization current increases rapidly. That is, the difference between the energization current during rotation and the energization current during rotation stop (lock) is large. For this reason, the drive completion determination based on the current threshold can be performed relatively easily and accurately.

  On the other hand, when the driven part is a durable product after endurance, there are usually many factors that hinder the driving of the driven part such as deposit, and the rotational speed of the motor becomes slow, so the double contact of the commutator The period is long and the ripple is large. Therefore, the ripple can be detected easily and accurately. On the other hand, with regard to the energization current value, since the rotation speed of the motor is slow, the energization current increases even during rotation as shown in FIG. 18, and the difference between the current value during rotation and the current value during locking is large. Is smaller than the initial product.

  That is, in the case of the initial product, the drive completion determination based on the energized current can be performed more easily and accurately, and in the case of the durable product, the drive completion determination based on the ripple cycle can be performed easily and accurately. Further, as described above, since the durable product has a longer ripple cycle than the initial product, it is possible to roughly distinguish the initial product or the durable product based on the ripple cycle.

  Therefore, the determination and selection means in the in-vehicle motor drive device according to claim 4 compares the ripple period and a preset selection threshold as described in claim 5, for example, and as a result of the comparison, the ripple period is determined. Is selected, the determination result by the second drive completion determination unit is selected, and when the ripple period is equal to or less than the selection threshold, the determination result by the first drive completion determination unit is selected. it can.

  In other words, if the ripple period is larger than the selection threshold (when the rotation is slow), it is judged as a durable product or a state close thereto, and the drive completion determination based on the ripple period is selected, and the ripple period is equal to or less than the selection threshold. In this case (when the rotation is fast), it is determined that the product is an initial product or a state close thereto, and the drive completion determination based on the current threshold is selected.

  With this configuration, the drive completion of the driven unit is determined by the appropriate drive completion determination unit corresponding to the state of the driven unit, out of the first or second drive completion determination unit. Regardless of the state of the part (initial product or durable product), it is possible to accurately determine the completion of the drive.

  By the way, the current flowing through the motor is affected by the power supply voltage of the motor, the environment around the motor, and the like. For example, the greater the power supply voltage, the greater the current flowing through the motor, and the faster the rotational speed. For example, even if the power supply voltage is constant, if the temperature around the motor increases, the resistance value of the motor (more precisely, the electrical resistance value of the motor winding) increases, the current flowing through the motor decreases, and the rotational speed becomes Become slow. Therefore, when the motor is driven in an environment where the temperature change and the power supply voltage change are severe, for example, around the engine of an automobile, depending on the change level, the above threshold values may not be fixed and fixed accurately. There is a possibility that the drive completion (motor lock) of the driven part cannot be detected.

  Therefore, in the in-vehicle motor driving device according to each of the above-described claims, the threshold values of the current threshold value, the ripple circumference threshold value, and the ripple detection threshold value are motors such as the above-described motor power supply voltage and ambient temperature, respectively. It is preferable that the setting can be appropriately changed according to an environmental parameter that is a parameter that affects the current-carrying current characteristics of the motor by acting directly or indirectly on the motor separately from the load.

  Specifically, the invention according to claim 6 is the vehicle-mounted motor drive device according to any one of claims 1, 4, and 5, and includes an environmental parameter detection unit that detects the environmental parameter, and an environmental parameter detection unit. Based on the detected environmental parameter, a current threshold value is calculated so that the completion of driving of the driven part is accurately determined, and a first threshold value command corresponding to the calculation result is output to the first threshold value setting means. 1 threshold value command output means. The first threshold value setting means sets the current threshold value in accordance with the first threshold value command from the first threshold value command output means.

  According to the on-vehicle motor drive device configured as described above, an appropriate current threshold value corresponding to the environmental parameter is calculated and set, so that the driven part can be accurately stopped even if the environmental parameter varies. It is possible to stop or reduce the energization of the motor immediately after the drive is stopped.

  More specifically, for example, as described in claim 7, the environmental parameter detection means directly or indirectly detects the temperature of the motor as the environmental parameter, and the first threshold command output means The current threshold value may be calculated so that the current threshold value decreases as the motor temperature detected by the parameter detection means increases.

  Even if the power supply voltage is constant, when the motor temperature increases, the resistance value of the motor winding increases and the energization current decreases. Therefore, if the current threshold is made lower as the motor temperature is higher, the current threshold will be set lower accordingly even if the energization current becomes lower overall due to temperature rise. Regardless, it is possible to accurately determine the completion of driving of the driven part.

  In particular, it is more effective to apply the invention according to claim 7 when the motor is exposed to an environment where the temperature change is severe, for example, in the vicinity of an internal combustion engine of an automobile. The same applies to claims 10 and 13 described later.

  The temperature of the motor can be detected by, for example, directly detecting the temperature by attaching a temperature sensor directly to the motor body or by attaching it as close to the motor winding as possible inside the motor. Needless to say, for example, any temperature in the vicinity of the motor may be detected and used as the motor temperature (or the motor temperature is estimated). The same applies to claims 10 and 13 described later.

  Further, for example, as described in claim 8, the environmental parameter detection means detects the power supply voltage supplied to the motor as the environmental parameter, and the first threshold command output means is detected by the environmental parameter detection means. The current threshold value may be calculated so that the value of the current threshold value decreases as the power supply voltage decreases.

  When the power supply voltage is lowered, the motor energization current is also lowered. However, as described above, if the current threshold value is also lowered as the power supply voltage is lowered, the driven part can be accurately driven regardless of fluctuations in the power supply voltage. Can be determined.

  In particular, it is more effective to apply the invention according to claim 8 when it is necessary to drive a motor by receiving a power supply having a relatively large voltage fluctuation, such as a battery of an automobile. The same applies to claims 11 and 14 described later.

  Next, the invention according to claim 9 is the in-vehicle motor drive device according to any one of claims 2 to 5, and includes an environmental parameter detection means (same as claim 6) and the environmental parameter detection means. Based on the detected environmental parameter, a ripple cycle threshold value is calculated so that the driving completion of the driven part is accurately determined, and a second threshold value command corresponding to the calculation result is output to the second threshold value setting means. Second threshold command output means. The second threshold value setting means sets the ripple cycle threshold value in accordance with the second threshold value command from the second threshold value command output means.

  According to the on-vehicle motor drive device configured as described above, an appropriate value of the ripple period threshold value according to the environmental parameter is calculated and set, so that the driven unit is stopped even if the environmental parameter varies. It is possible to make an accurate determination, and it is possible to stop or reduce the energization of the motor immediately after the drive is stopped.

  More specifically, for example, as described in claim 10, the environmental parameter detecting means directly or indirectly detects the temperature of the motor as the environmental parameter, and the second threshold command output means is an environmental parameter. The ripple cycle threshold value may be calculated so that the ripple cycle threshold value increases as the motor temperature detected by the parameter detection means increases.

  Even if the power supply voltage is constant, when the motor temperature increases, the energization current decreases, the motor rotation speed decreases, and the ripple period increases. Therefore, if the ripple cycle threshold is increased as the motor temperature is higher, the ripple cycle threshold is set to a larger value in accordance with the increase in the ripple cycle as a whole. Completion of driving of the driven part can be accurately determined regardless of the temperature of the motor.

  Further, for example, as described in claim 11, the environmental parameter detection means detects the power supply voltage supplied to the motor as the environmental parameter, and the second threshold command output means is detected by the environmental parameter detection means. The ripple cycle threshold value may be calculated so that the value of the ripple cycle threshold value increases as the power supply voltage decreases.

  When the power supply voltage is lowered, the motor energization current is also lowered and the rotation speed is lowered, and the ripple cycle is lengthened. However, if the ripple cycle threshold is increased as the power supply voltage is lowered as described above, Completion of driving of the driven part can be accurately determined regardless of voltage fluctuation.

  Next, the invention described in claim 12 is the in-vehicle motor drive device described in claim 3, wherein the environmental parameter detection means (same as claim 6) and the environmental parameter detected by the environmental parameter detection means are used. And a third threshold command output means for calculating a ripple detection threshold so that the period of the ripple is accurately detected, and outputting a third threshold command according to the calculation result to the third threshold setting means. I have. The third threshold value setting means sets the ripple detection threshold value according to the third threshold value command from the third threshold value command output means.

  According to the on-vehicle motor drive device configured in this way, an appropriate value for the ripple detection threshold corresponding to the environmental parameter is calculated and set, so that the occurrence of ripple can be accurately detected even if the environmental parameter varies. It is also possible to accurately measure the ripple period based on this, and to accurately determine the drive stop of the driven part. Therefore, it becomes possible to stop or reduce the energization to the motor immediately after the drive is stopped.

  The configuration of the invention described in claim 12 can be similarly provided in the invention of claim 4 subordinate to claim 3, and also in the invention of claim 5 subordinate thereto. Thus, the effect of the above-described invention of claim 12 can be obtained.

  As a specific configuration of the invention described in claim 12, for example, as described in claim 13, the environmental parameter detection means detects the temperature of the motor as the environmental parameter directly or indirectly, and the third threshold command The output means may calculate the ripple detection threshold so that the value of the ripple detection threshold decreases as the motor temperature detected by the environmental parameter detection means increases.

  Even if the power supply voltage is constant, if the motor temperature rises, the resistance value of the motor winding increases and the energization current decreases, and the ripple peak value also decreases. Therefore, if the ripple detection threshold is lowered as the motor temperature is higher, the ripple detection threshold is set to a lower value accordingly even if the ripple peak value is lowered due to a temperature rise (decreasing energization current). Therefore, the ripple period can be accurately determined regardless of the motor temperature.

  Further, for example, as described in claim 14, the environmental parameter detection means detects the power supply voltage supplied to the motor as the environmental parameter, and the third threshold command output means is detected by the environmental parameter detection means. The ripple detection threshold value may be calculated such that the lower the power supply voltage, the lower the ripple detection threshold value.

  When the power supply voltage is lowered, the energization current of the motor is reduced, so that the ripple peak value is also reduced. Thus, if the ripple detection threshold is also lowered as the power supply voltage decreases as described above, the ripple cycle can be accurately determined regardless of fluctuations in the power supply voltage.

  By the way, even if the environmental parameters are the same, there may be a difference in characteristics depending on individual differences of the motors themselves. For example, even if the same motor is designed, even if it is rotated in exactly the same environment and the same power supply due to manufacturing tolerances and various other subtle individual differences (electrical or mechanical individual differences) May be different. Further, if an abnormality occurs in each threshold command output means, there is a possibility that the calculation of each threshold according to the environmental parameter may not be accurately performed. In this case, the threshold value set by the threshold value setting means is not an appropriate value according to the individual motor characteristics or an appropriate value according to the environmental parameter, and the drive completion of the driven part may not be accurately determined. There is sex.

  Therefore, the on-vehicle motor drive device according to any one of claims 6 to 14 configured to perform threshold calculation according to an environmental parameter further includes the threshold command output as described in claim 15, for example. The calculation result of the threshold value (corresponding current threshold value, ripple cycle threshold value, or ripple detection threshold value) by the means (one of the first to third threshold value command output means) is calculated based on the energization current of the motor detected by the current detection means. Threshold correction means for correcting based on the value may be provided. Then, the threshold command output means may output a threshold command (any of the corresponding first to third threshold commands) corresponding to the threshold value corrected by the threshold correction means to the corresponding threshold setting means. .

  The term “correction” used herein refers to correction for a current threshold value or a ripple cycle threshold value so that the drive completion of the driven unit can be accurately determined, and for the ripple detection threshold value, It means that the value is corrected so that the period is accurately detected.

  With this configuration, for example, when the power supply voltage is normal and the temperature detected by the environmental parameter detection means is high, the first threshold value command output means calculates the current threshold value to be lower according to the temperature. If the actually detected energization current is larger than the value assumed in the design, the motor winding resistance value is expected to be lower than the design value. The correction means can correct the value to a high value.

  Also, for example, the ripple cycle threshold is reduced to a small value due to an abnormality in the second threshold command output means, even though the environmental parameter detection means detects that the power supply voltage is low (that is, the rotational speed of the motor should be slow). In such a case, it is possible to correct the ripple period threshold value to a large value based on the energization current (small value corresponding to the power supply voltage) detected by the current detection means. It becomes.

  Further, for example, although the environmental parameter detection means detects that the temperature of the motor is low (that is, the energization current should increase and the peak value of the ripple should also increase), the abnormality is caused by the third threshold command output means. The ripple detection threshold may be calculated to a low value, but in such a case, the ripple detection threshold is corrected to a large value based on the energization current detected by the current detection means (a large value corresponding to the motor temperature). It is possible to do.

  The correction of each threshold by the threshold correction means may be performed based on the value of the inrush current at the start of the energization current, or may be performed based on the value of the energization current during rotation. The timing at which the current is applied can be determined as appropriate.

  The in-vehicle motor drive device according to any one of claims 1 to 15 includes, for example, a drive unit, a threshold setting unit, and a drive completion determination unit in the same semiconductor integrated circuit. You may make it form. By doing so, it becomes possible to provide a semiconductor integrated circuit incorporating a motor drive and its lock detection function at a low cost.

  In the vehicle-mounted motor drive device according to any one of claims 6 to 15, in particular, the drive means, the threshold setting means, and the drive completion determination means are all the same semiconductor integrated circuit as described in claim 17. The semiconductor integrated circuit is further provided with serial communication means for performing serial communication with the outside in the semiconductor integrated circuit, and the threshold setting means is converted from the corresponding threshold command output means to the serial data format. The threshold command transmitted in this way may be received via serial communication means.

  As described above, if each threshold command from the outside of the semiconductor integrated circuit is received by serial communication, for example, a plurality of types of data (a plurality of types of threshold commands) can be received by one transmission line. Wiring and the overall cost of the apparatus can be reduced.

  Further, in the in-vehicle motor drive device according to the fifteenth aspect, in particular, as in the eighteenth aspect, in addition to the drive means, the threshold setting means, and the drive completion determination means, the current detection means is also within the same semiconductor integrated circuit. The motor energization current detected by the current detection means may be output as an analog value to the outside of the semiconductor integrated circuit. In addition, A / D conversion means for receiving the value of the energization current output from the semiconductor integrated circuit and converting it into digital data is provided, and the threshold correction means is a value of the energization current after conversion by the A / D conversion means. The above correction may be performed based on the above.

  According to the on-vehicle motor drive device configured as described above, it is possible to provide a semiconductor integrated circuit incorporating a motor drive, its lock detection function, and a conduction current detection / output function at low cost, and this semiconductor Based on the energization current output from the integrated circuit, the threshold correction means can reliably correct the threshold.

  The in-vehicle motor drive device according to the eighteenth aspect of the present invention may further include the configuration according to the seventeenth aspect (provided with serial communication means and a threshold command receiving function using the same). . Also, in each of the vehicle-mounted motor drive devices described in claims 16 and 17, the current detection means may be formed in the same semiconductor integrated circuit as in the case of claim 18.

  In the in-vehicle motor drive device according to the seventeenth or eighteenth aspect, for example, as described in the nineteenth aspect, a plurality of types of semiconductor integrated circuits may be provided. In that case, the threshold value command output means individually calculates a corresponding threshold value for each of the plurality of types of semiconductor integrated circuits and transmits a threshold value command according to the calculation result, and from the threshold value command output means to each semiconductor integrated circuit. The threshold command is preferably transmitted using a common transmission line in the serial data format.

By doing so, it is possible to transmit threshold commands to a plurality of semiconductor integrated circuits with reduced wiring, and it is possible to reduce the cost, weight, and space of the entire apparatus.
Here, the stop or reduction of the energization of the motor by the drive unit based on the determination result of the drive completion by the first drive completion determination unit is specifically realized as described in, for example, claim 20 or 21. be able to.

  First, the invention according to claim 20 is the in-vehicle motor drive device according to any one of claims 1 to 19, wherein when the drive completion of the driven portion is determined by the drive completion determining means, the energization suppression requesting means However, it requests the driving means to stop or reduce the energization of the motor. The drive means stops or reduces the energization to the motor when the above request is made from the energization suppression request means, regardless of the content of the drive command from the control means.

  In this case, there are two types of drive completion determination means (first drive completion determination means and second drive completion determination means) and determination selection means (that is, the configuration according to claim 4 is provided). When the drive completion is determined by any one of the drive completion determination units selected by the determination selection unit, the energization suppression request unit makes the request to the drive unit.

  On the other hand, the invention according to claim 21 is the in-vehicle motor drive device according to any one of claims 1 to 19, wherein when the drive completion of the driven part is determined by the drive completion determination means, the drive completion notification The means notifies the control means accordingly. Upon receiving this notification, the control means outputs an energization suppression command, which is a drive command for stopping or reducing energization to the motor, to the drive means. When the energization suppression command is input from the control unit, the driving unit stops or reduces energization to the motor in accordance with the energization suppression command.

  In this case, when the drive completion determination unit includes two types (first drive completion determination unit and second drive completion determination unit) and determination selection unit, the control unit receives the drive completion notification unit from the drive completion notification unit. When the notification is made when the drive completion is determined by any one of the drive completion determination units selected by the determination selection unit, an energization suppression command may be output. Alternatively, the drive completion notification means may notify the control means only when drive completion is determined by any one of the drive completion determination means selected by the determination selection means.

  That is, in the case of the former (claim 20), if there is a request for stopping or reducing energization upon completion of driving of the driven part, even if the drive command by the control means has the content that energization should be continued. The energization is stopped or reduced in preference to the above request. In the latter case (claim 21), the operation of the drive means is basically performed based on the drive command from the control means. When the driving of the unit is completed, this is notified to the control means, and the drive means stops or reduces the energization only after the energization stop or reduction command (energization suppression command) is output from the control means.

  Therefore, in any of the above cases, when the driving of the driven part is completed, the driving unit can reliably stop or reduce the energization of the motor. However, in the latter case (Claim 21), it is necessary to notify the control means once the drive is completed, and the control means receiving it outputs a current-suppression instruction, so the former (Claim 20). ), There is a possibility that the time from the completion of driving to the stoppage or reduction of energization becomes longer. Therefore, if it is necessary to stop or reduce energization as soon as possible after the completion of driving, the former configuration (claim 20) is preferable.

  By the way, the on-vehicle motor drive device according to claim 1, which achieves good drive response of the driven part, reduced heat generation, and improved durability and reliability as described above, for example, It is more effective when the device drives the drive unit to either the open position or the closed position.

  In particular, it is more effective if the driven portion is a vehicle-mounted valve provided in an air intake path to the internal combustion engine or an exhaust path from the internal combustion engine in the internal combustion engine of the vehicle. A vehicle-mounted valve provided in a path through which air is drawn or discharged in an internal combustion engine of a vehicle is affected by viscous resistance due to deposits or the like as described above. This is because the energization can be stopped or reduced by detecting the driving completion (opening / closing completion) with certainty.

Preferred embodiments of the present invention will be described below with reference to the drawings.
[First Embodiment]
FIG. 1 is a schematic configuration diagram of an SCV (swirl control valve) drive system according to an embodiment to which the present invention is applied. The SCV drive system of this embodiment is mounted on a vehicle. As shown in FIG. 1, an internal combustion engine 2 and an SCV (swirl control valve) 10 that opens and closes a first intake port 5a in the internal combustion engine 2 are mainly used. A motor 11 that opens and closes the SCV 10 and an electronic control unit 1 that controls the SCV 10 by controlling energization of the motor 11 are provided.

  The internal combustion engine 2 includes a cylinder 3 and a piston 4, and is a well-known engine that obtains a driving force of a vehicle by burning an air-fuel mixture in a combustion chamber 6. Intake into the combustion chamber 6 is performed via an intake pipe 5 serving as an air intake path. The intake pipe 5 is provided in the vicinity of the combustion chamber 6 with two ports, a first intake port 5a and a second intake port 5b. Divided into

  The intake pipe 5 is provided with a throttle valve 8, and an intake pipe length switching valve used in an ACIS (Acoustic Control Induction System) that switches and controls the length of the intake pipe 5 in accordance with the rotational speed of the internal combustion engine. 9 and an auxiliary intake pipe 5c are configured so that the intake pipe length can be switched by opening and closing the intake pipe length switching valve 9 to switch the intake air amount, the intake timing, and the like. Therefore, the air flowing into the intake pipe 5 flows into the two intake ports 5a and 5b via the throttle valve 8 and the intake pipe length switching valve 9 (or the auxiliary intake pipe 5c).

  The SCV 10 provided in the first intake port 5a is a known valve for generating an overflow in the air in the combustion chamber 6 to increase the combustion efficiency in the low / medium rotation range of the internal combustion engine. The SCV 10 is driven to open and close (open or close) as described with reference to FIG. That is, the rotating shaft of the motor 11 and the rotating shaft 20 of the SCV 10 are mechanically connected via a reduction gear or the like, and when the motor 11 rotates, the rotational driving force of the SCV 10 rotates via the reduction gear or the like. The SCV 10 is driven to open and close by being transmitted to the shaft 20. Then, when the SCV 10 comes into contact with the inner wall of the first intake port 5a and the opening operation is completed, or when the SCV 10 comes into contact with the restricting projection 21 and the closing operation is completed, the SCV 10 can no longer rotate. Naturally, the rotation of the motor 11 is also forcibly terminated. Since the details of the opening / closing drive of the SCV 10 have already been described with reference to FIG. 16, the description thereof is omitted here.

  Note that the SCV 10 actually does not have the restricting projection 21 in the position of the rotating shaft 20, the state in which the opening operation is completed, the state in which the closing operation is completed, and the like. Actually, the reduction gear interposed between the motor 11 and the SCV 10 is restricted at each position corresponding to the open position and the closed position of the SCV 10, and as a result, the movement of the SCV 10 is restricted. That is, when the SCV 10 during the opening operation reaches the open position, the reduction gear does not move any further, and the SCV 10 does not necessarily rotate. Also in the closing operation, when the SCV 10 in the closing operation reaches the closing position, the reduction gear does not move any more and the SCV 10 is also stopped. However, in this embodiment, when the SCV 10 reaches the open position or the closed position, the motor 11 cannot be moved any more and the motor 11 is locked (that is, the motor 11 is forcibly positioned by an external factor). For easy understanding, the SCV 10 is described with a conceptual configuration as shown in FIG.

  An exhaust pipe 7 as an exhaust path for discharging exhaust gas after combustion is provided with an EGR valve 13 for opening and closing an EGR pipe 12 for an EGR (Exhaust Gas Recirculation) system, and this EGR 13 is opened. Thus, the exhaust gas after combustion can be returned to the combustion chamber 6 again.

  The electronic control device 1 is for controlling the entire internal combustion engine 2 including the motor 11 for driving the SCV 10, and includes a microcomputer 15 as a control means that plays a central role in various controls, and a motor drive IC 16 that drives the motor 11. And a power supply voltage detection circuit 17 that detects a voltage (hereinafter simply referred to as “power supply voltage”) of an in-vehicle battery (not shown) that is also a power supply of the motor 11. When a driving command is output from the microcomputer 15 to the motor driving IC 16, the motor driving IC 16 energizes the motor 11 in accordance with the driving command and drives the motor 11. As a result, the SCV 10 is driven to the open position or the closed position.

As will be described later, the motor driving IC 16 detects the energization current of the motor 11 and outputs the value (Id) to the microcomputer 15 or outputs various output data SDO corresponding to the driving state of the SCV 10 to the microcomputer 15. To do. In addition, the clock signal SCK from the microcomputer 15 and various input data SDI are input to the motor driving IC 16. Note that both the output data SDO and the input data SDI are input / output in a serial data format.

Further, the SCV drive system of the present embodiment includes a water temperature sensor 18 that detects the temperature of the cooling water of the internal combustion engine 2 (hereinafter simply referred to as “water temperature”). The power supply voltage detected by the power supply voltage detection circuit 17 and the water temperature detected by the water temperature sensor 18 are input to the microcomputer 15. Then, the microcomputer 15 executes various calculations required for energization driving of the motor 11 as described later based on the input power supply voltage and water temperature. The motor driving IC 16 is provided with a current detection circuit 36 (see FIG. 2) for detecting the energization current of the motor 11 as will be described later. The energization current Id detected by the current detection circuit 36 is provided. Is also output to the microcomputer 15.

  Next, a specific configuration of the electronic control device 1 will be described with reference to FIG. FIG. 2 is an explanatory diagram showing the configuration of the electronic control device 1. As will be described in detail later, the motor driving IC 16 included in the electronic control device 1 includes an H-bridge driving circuit including four switching elements as a driving circuit for controlling energization to the motor 11. The drive command from the microcomputer 15 is a command signal for turning on / off each switching element constituting the H-bridge drive circuit.

  Then, the microcomputer 15 issues a drive command (continuous energization command of the present invention) for energizing the motor 11 with DUTY 100% when a predetermined condition (details are omitted) for opening or closing the SCV 10 is satisfied. Output to the motor drive IC 16. Thereafter, when the drive of the SCV 10 is completed, the drive at DUTY 100% is stopped, and a drive command for stopping the energization of the motor 11 (the energization suppression command of the present invention) is output.

  Further, the microcomputer 15 detects that the motor driving IC 16 has finished driving the SCV 10 based on the power supply voltage detected by the power supply voltage detection circuit 17 and the water temperature detected by the water temperature sensor 18 (opening operation or completion of closing operation). Various threshold values used for the calculation are calculated and output to the motor driving IC 16. This calculation result is input to the motor drive IC 16 through the serial input line 82 as one of the input data SDI. The motor driving IC 16 is formed by forming each circuit shown in the inside of one semiconductor integrated circuit.

  Next, as shown in FIG. 2, the motor drive IC 16 includes an H-bridge drive circuit including N-channel MOSFETs (hereinafter simply referred to as “FETs”) 31 to 34 as four switching elements.

  More specifically, in the H-bridge drive circuit, the drain is connected to the power supply voltage Vb that is the potential of the + terminal of the in-vehicle battery, the source is connected to the + terminal of the motor 11, and the drain is connected to the power supply voltage Vb. A FET 32 whose source is connected to the negative terminal of the motor 11, a FET 33 whose drain is connected to the negative terminal of the motor 11, and whose source is connected to the potential of the negative terminal of the in-vehicle battery (hereinafter referred to as “ground potential”); The FET 34 has a drain connected to the + terminal of the motor 11 and a source connected to the ground potential. That is, the FET 31 and the FET 33 form a switching element pair for causing the motor 11 to pass a current in the normal rotation direction from the + terminal to the − terminal, and the FET 32 and the FET 34 are connected to the motor 11 from the − terminal to the + terminal. This is a pair of switching elements for flowing a current in the reverse direction. In this embodiment, it is assumed that the SCV 10 is driven to the open position when a current in the forward direction flows through the motor 11, and the SCV 10 is driven to the closed position when a current in the reverse direction flows. . In addition, diodes (parasitic diodes) are arranged in parallel between the drains and the sources of the FETs 31 to 14 with the source side to the drain side in the forward direction, but are not shown in FIG.

  Further, when a drive command for turning on the FET 31 is input, the motor drive IC 16 outputs an on drive voltage for turning on the FET 31 to turn on the FET 31 and turn off the FET 31. Is inputted, a pre-drive circuit 41 for turning off the FET 31 by outputting an off drive voltage for turning off the FET 31, and a drive command for turning on the FET 32 are inputted. A pre-drive circuit 42 that outputs an on drive voltage to turn on the FET 32 and outputs an off drive voltage to turn off the FET 32 when a drive command to turn off the FET 32 is input; ON drive to turn on FET 33 when a drive command to turn on FET 33 is input A pre-drive circuit 43 for turning off the FET 33 by outputting an off drive voltage for turning off the FET 33 when a drive command for turning off the FET 33 is input. When a drive command for turning on the FET 34 is input, an on drive voltage for turning on the FET 34 is output to turn on the FET 34. When a drive command for turning off the FET 34 is input, the FET 34 is turned off. And a pre-drive circuit 44 that outputs an off-drive voltage for turning off the FET 34.

  Each of the on-drive voltage and the off-drive voltage described above is output in response to a command signal from the drive logic generation circuit 37. Based on the drive command from the microcomputer 15, the drive logic generation circuit 37 outputs each command signal so that energization according to the drive command (energization to the motor 11) is performed.

  That is, when a drive command indicating that a current in the forward direction should flow through the motor 11 is input to the drive logic generation circuit 37, a high-level command signal is sent to each pre-drive circuit 41, 43 corresponding to the FET 31 and FET 33. At the same time, a low level command signal is output to the other two pre-drive circuits 42 and 44. Thereby, the FET 31 and the FET 33 are turned on, and a current in the forward rotation direction flows.

  On the other hand, when a drive command indicating that a current in the reverse direction should flow through the motor 11 is input to the drive logic generation circuit 37, a high-level command signal is output to each pre-drive circuit 42 and 44 corresponding to the FET 32 and FET 34. At the same time, a low level command signal is output to the other two pre-drive circuits 41 and 43. As a result, the FET 32 and the FET 34 are turned on, and a current in the reverse direction flows.

  When a drive command indicating that energization should be stopped while the motor 11 is energized is input to the drive logic generation circuit 37, the drive logic generation circuit 37 circulates the energy remaining in the winding of the motor 11. Command signal is output. For example, when energization in the forward rotation direction is stopped, the FET 33 is turned off and the FET 32 is turned on (that is, the FETs 31 and 32 are turned on) to recirculate the residual energy of the motor 11.

  Further, the four FETs 31 to 34 constituting the H bridge drive circuit are configured as so-called sense FETs with a current detection function. The current flowing through the current detection FETs (comprising only a part of the plurality of small capacitance FETs constituting the entire FET) in the two high-side FETs 31 and 32 is taken into the current detection circuit 36. The current detection circuit 36 detects the energization current of the motor 11 based on the taken current, and outputs a voltage (voltage proportional to the current value) according to the detection result. The FETs 31 to 34 may not have a current detection function. For example, the current detection circuit 36 may detect a current flowing between a connection point on the source side of the FET 33 and the FET 34 and the ground terminal.

  An energization current Id (analog value; actually, a voltage corresponding to the energization current value, the same applies hereinafter) detected by the current detection circuit 36 is output to the microcomputer 15 and energized in the motor driving IC 16. The current is output to the current monitor circuit 51 and the high pass filter (HPF) 48.

  The HPF 48 removes high-frequency components included in the energization current Id. In this embodiment, high-frequency components other than the ripple components are detected so that ripples included in the energization current Id (details will be described later) can be accurately detected. Remove.

  The direct current component is further removed by the AC coupling 52 from the energization current Id after the high frequency component removal by the HPF 48. Then, the energization current Id after the removal of the DC component is amplified at a predetermined amplification factor by the ripple amplification circuit 53 and input to the ripple monitor circuit 54.

  The AC coupling 52 is a known circuit that removes a direct current component and outputs only an alternating current component, and includes a coupling capacitor 66 having one end connected to the output side of the HPF 48 and the other end connected to a resistor 67. The other end of the resistor 67 connected to the coupling capacitor 66 is connected to the ripple amplifier circuit 53 in the next stage and is connected to the ground potential via the resistor 68 and the capacitor 69.

  The ripple amplifier circuit 53 is a well-known circuit that amplifies the output from the AC coupling 52, that is, the ripple included in the energization current Id, with a predetermined amplification factor. And a feedback resistor 72. The ripple output from the AC coupling 52 is input to the inverting input terminal of the operational amplifier 73 via the input resistor 71, amplified, and output to the ripple monitor circuit 54. The non-inverting input terminal of the operational amplifier 73 is connected to the ground potential.

  The amplification factor of the ripple amplifier circuit 53 is configured to be changeable by an amplification factor setting command input from the microcomputer 15 via the serial input line 82. Specifically, the feedback resistor 72 is configured such that its resistance value is changed according to the amplification factor setting command, and the amplification factor of the ripple amplification circuit 53 is changed as a result of this resistance value setting change. The

  Here, the fact that ripples are included in the energization current of the motor 11 will be described. The motor 11 of this embodiment is a DC motor that is driven by a power supply voltage Vb that is a DC power supply. That is, as shown in FIG. 3, a plurality of (three in this embodiment) commutators 27a, 27b, and 27c are formed on one end side of the rotating shaft 29 of the motor 11 along the outer peripheral portion of the rotating shaft 29. In addition, this is a DC motor having a known configuration in which brushes 25 and 26 are fixedly installed on both sides of the rotating shaft 29 in the housing of the motor 11. The supply of the power supply voltage Vb to the motor 11 is performed via the brushes 25 and 26.

  In the motor 11 having such a configuration, as shown in FIG. 3A, the brush 25 connected to the power supply voltage Vb contacts (slidably contacts) one commutator 27c and is connected to the ground potential. In the state in which 26 also is in contact with one commutator 27a, as is clear from the figure, current flows in any of the three motor windings 28ab, 28bc, 28ca.

  On the other hand, when two commutators are in contact with one brush, no current flows through all of the three motor windings 28ab, 28bc, 28ca. That is, as shown in FIG. 3B, when the two commutators 27c and 27b come into contact with the brush 25 connected to the power supply voltage Vb, the motor connected to the two commutators 27c and 27b. No current flows through the winding 28bc. Therefore, the energization current of the motor 11 as a whole becomes larger than that in the state shown in FIG.

  While the motor 11 is rotating, a period (double contact period) in which two commutators are in contact with one brush as shown in FIG. Therefore, the energization current during the rotation of the motor 11 is a current including a ripple as shown in FIG. As shown in FIG. 4, when energization to the motor 11 is started, an inrush current flows immediately after the start of the energization, but after that, during rotation, the energization current becomes almost constant when viewed macroscopically. However, microscopically, as long as it rotates, ripples are generated due to the occurrence of a double contact period. This ripple occurs at a period T2 corresponding to the rotation speed of the motor 11. During the rotation of the motor 11, the energization current is suppressed to some extent by the back electromotive force.

  When the driving of the SCV 10 (for example, driving from the closed position to the open position) is completed and the rotation of the motor 11 is forcibly stopped (locked), the back electromotive force is lost and the energization current increases rapidly. And since it is not rotating, a ripple does not arise naturally, and an energization current (lock current) becomes constant. As described above, the energization characteristic that the energization current includes a ripple during rotation of the motor 11 and does not include the ripple when the motor 11 is locked is a characteristic unique to a DC motor having a brush and a commutator. In the present embodiment, after the driving of the SCV 10 is completed, when the microcomputer 15 determines that the driving is completed, the energization of the motor 11 is stopped as shown in FIG. This drive completion determination process will be described later.

  In the SCV drive system of the present embodiment, the completion of the opening operation or the closing operation of the SCV 10 is determined based on the energization current Id of the motor 11. Specifically, the determination is made based on the value of the energization current Id and the ripple included in the energization current Id. Therefore, in the present embodiment, the motor driving IC 16 includes the energizing current monitor circuit 51 for determining the completion of driving of the SCV 10 based on the value of the energizing current Id, and the driving of the SCV 10 based on the ripple included in the energizing current Id. And a ripple monitor circuit 54 for determining completion.

  The energization current monitor circuit 51 includes a comparator 63 that compares the energization current Id detected by the current detection circuit 36 with an opening / closing completion current threshold, and the energization current Id is input to a non-inverting input terminal of the comparator 63. The switching completion current threshold is generated by dividing the internal drive voltage Vc generated by a power supply circuit (not shown) inside the motor drive IC 16 by the two resistors 61 and 62. That is, the energization current monitor circuit 51 has one end connected to the internal drive voltage Vc, the other end connected to the resistor 62, and one end connected to the current threshold setting resistor 61. A resistor 62 having an end connected to the ground potential, and a voltage at the connection point of the resistors 61 and 62 (a divided value of the internal drive voltage Vc) is input to the inverting input terminal of the comparator 63 as a switching completion current threshold value. Is done.

  The current threshold setting resistor 61 is configured such that its resistance value is set and changed in response to a current threshold setting command (corresponding to the first threshold command of the present invention) input from the microcomputer 15 via the serial input line 82. In response to this change in the resistance value setting, the switching completion current threshold value input to the comparator 63 is changed.

  With such a configuration, the energization current Id from the current detection circuit 36 is compared with the switching completion current threshold by the comparator 63. When the energization current Id is smaller than the switching completion current threshold, the output of the comparator 63 is at a low level, but when the energization current Id is equal to or greater than the switching completion current threshold, the output of the comparator 63 is at a high level.

  The open / close completion current threshold value is a determination criterion for determining the completion of driving of the SCV 10 and is a value that does not reach when the motor 11 is rotating (while the SCV 10 is being driven) after the start of energization of the motor 11. In addition, an energization current value (specifically, a voltage value corresponding to the energization current value) that is reached or exceeded when the motor 11 is locked (the SCV 10 has been driven) is set as the open / close completion current threshold value. A current threshold setting command is output from the microcomputer 15 to the current threshold setting resistor 61. That is, the set open / close completion current threshold value is set to a value that can distinguish between the energization current that flows when the motor rotates and the energization current that flows when the motor is in a locked state and does not rotate. By setting such values, it is possible to reliably detect at least one of the fully open state and the fully closed state without requiring a sensor or the like that detects the position of a member driven by a motor such as the SCV10. Can do.

  Therefore, after the start of driving of the SCV 10 due to the start of energization of the motor 11, while the output from the comparator 63 is at a low level, the SCV 10 is being driven (turning), and when the output has turned to a high level. Thus, the drive of the SCV 10 is stopped and the motor 11 is locked. An open / close completion detection signal that is an output of the comparator 63 is sent to the microcomputer 15 via the serial output line 83. The microcomputer 15 determines the driving state of the SCV 10 based on the opening / closing completion detection signal from the comparator 63.

  The ripple monitor circuit 54 includes a comparator 78 that compares the output from the ripple amplifier circuit 53 with the ripple detection threshold, and the output from the ripple amplifier circuit 53 is input to the non-inverting input terminal of the comparator 78. The ripple detection threshold is generated by dividing the internal drive voltage Vc by the two resistors 76 and 77. That is, the ripple monitor circuit 54 has one end connected to the internal drive voltage Vc and the other end connected to the resistor 77, and one end connected to the ripple detection threshold setting resistor 76. A resistor 77 having the other end connected to the ground potential, and the voltage at the connection point between these resistors 76 and 77 (the divided value of the internal drive voltage Vc) is input to the inverting input terminal of the comparator 78 as a ripple detection threshold. Is done.

  The resistance value of the ripple detection threshold value setting resistor 76 is changed in accordance with a ripple detection threshold value setting command (corresponding to the third threshold value command of the present invention) input from the microcomputer 15 via the serial input line 82. The ripple detection threshold value input to the comparator 78 is changed by changing the setting of the resistance value.

  With such a configuration, the input signal from the ripple amplifier circuit 53 is compared with the ripple detection threshold by the comparator 78. When the input signal is smaller than the ripple detection threshold, the output of the comparator 78 is at a low level, but when the input signal is greater than or equal to the ripple detection threshold, the output of the comparator 78 is at a high level.

  The ripple detection threshold value is a determination criterion for determining the occurrence of ripple, and is a value that does not reach when no ripple has occurred after the start of energization of the motor 11. A ripple detection threshold setting command is sent from the microcomputer 15 to the ripple detection threshold setting resistor 76 so that a value that reaches or exceeds when the error occurs (specifically, a voltage value corresponding to this value) is set as the ripple detection threshold. Is output. Explaining with reference to FIG. 4, the ripple detection threshold value is set to be smaller than the peak value of the ripple generated during the rotation of the motor 11. Therefore, after the start of driving of the SCV 10 due to the start of energization of the motor 11, a ripple occurs each time the output from the comparator 78 changes to a high level.

  The output of the comparator 78 is input to the timer 79. Each time the output of the comparator 78 changes from low level to high level (every rising edge detection), the timer 79 measures the elapsed time from the time when the output changes to high level. That is, every time the occurrence of a ripple is detected, the elapsed time from the time of occurrence is measured. Then, after the measurement is started, when the output of the comparator 78 once changes to the low level and then changes to the high level again (when the next ripple occurs), the measurement result so far is cleared and measurement is newly started. That is, the timer 79 measures the ripple period T2. The measurement result (elapsed time) by the timer 79 is output to the microcomputer 15 via the serial output line 83 at any time.

  In addition, the opening / closing completion ripple cycle threshold is set in the timer 79. When the measurement result is smaller than the opening / closing completion ripple cycle threshold, the opening / closing completion ripple cycle threshold is exceeded when the measurement result becomes equal to or higher than the opening / closing completion ripple cycle threshold. A detection signal is output from the timer 79. The opening / closing completion ripple cycle threshold is configured so that its value is changed according to a ripple cycle threshold setting command (corresponding to the second threshold command of the present invention) input from the microcomputer 15 via the serial input line 82. ing.

  With such a configuration, every time the output from the comparator 78 changes to a high level (that is, every time a ripple included in the energization current Id is detected), an elapsed time from that point is measured. When the output of the comparator 78 changes from low level to high level again before reaching the opening / closing completion ripple cycle threshold after starting measurement, the measurement value of the timer 79 is cleared and the opening / closing completion detection signal from the timer 79 also remains at low level. However, after the measurement is started, if the output of the comparator 78 does not change from the low level to the high level again (that is, the next ripple is not detected again), the timer 79 The open / close completion detection signal from becomes high level.

  The open / close completion ripple cycle threshold value is a determination criterion for determining the completion of driving of the SCV 10 as in the case of the open / close completion current threshold value described above, and the ripple generated during rotation of the motor 11 (during driving of the SCV 10). The value is set to be sufficiently larger than the period T2. Therefore, the timer 79 does not exceed the opening / closing completion ripple cycle threshold while the motor 11 is rotating. On the other hand, when the motor 11 is locked due to the completion of driving of the SCV 10, no ripple is generated, so that the timer 79 eventually outputs a high-level opening / closing completion detection signal exceeding the opening / closing completion ripple cycle threshold. The microcomputer 15 outputs a ripple cycle threshold setting command to the timer 79 in order to set the opening / closing completion ripple cycle threshold to the above value.

  Therefore, after the start of driving of the SCV 10 due to the start of energization of the motor 11, while the output from the timer 79 is at the low level, the SCV 10 is being driven (rotating), and the output from the timer 79 is at the high level. When it turns, it means that the driving of the SCV 10 is stopped and the motor 11 is locked. The open / close completion detection signal output from the timer 79 is sent to the microcomputer 15 via the serial output line 83 in the same manner as the open / close completion detection signal from the energization current monitor circuit 51. The microcomputer 15 determines the driving state of the SCV 10 based on the opening / closing completion detection signal from the timer 79.

  The motor driving IC 16 has a serial interface (hereinafter referred to as “serial I / F”) 46 for performing serial communication with the microcomputer 15. The microcomputer 15 also has a serial I / F (not shown). Accordingly, various input data SDI transmitted from the microcomputer 15 in the serial data format is input into the motor driving IC 16 via the serial input line 82 and the serial I / F 46.

  As described above, the serial data input via the serial input line 82 includes a current threshold setting command input to the energization current monitor circuit 51, a ripple detection threshold setting command input to the ripple monitor circuit 54, and a ripple. There are a periodic threshold setting command, an amplification factor setting command input to the ripple amplifier circuit 53, and the like. The clock signal SCK input from the microcomputer 15 via the clock line 81 is also input into the motor driving IC 16 via the serial I / F 46.

  Various data output from the motor driving IC 16 to the microcomputer 15 is also converted into a serial data format by the serial I / F 46 and then transmitted to the microcomputer 15 via the serial output line 83. As described above, the serial data transmitted through the serial output line 83 includes an open / close completion detection signal (that is, an output of the comparator 63) from the energization current monitor circuit 51 and an open / close completion detection from the ripple monitor circuit 54. Signal (ie, the output of the timer 79).

  The microcomputer 15 includes an A / D conversion circuit 30 that converts various analog data input from the outside into digital data. The energization current Id input to the microcomputer 15 is converted into A / D by the A / D conversion circuit 30. D-converted. The power supply voltage Vb detected by the power supply voltage detection circuit 17 and the water temperature detected by the water temperature sensor 18 are also A / D converted by the A / D conversion circuit 30. The microcomputer 15 calculates and corrects the above-described various threshold values based on the energized current Id after the A / D conversion, the power supply voltage Vb, the water temperature, and the like, and inputs various threshold setting commands according to the calculation and correction results. Data SDI is input to the motor driving IC 16 via the serial input line 82.

  Further, both the open / close completion detection signal from the energization current monitor circuit 51 and the drive completion signal from the ripple monitor circuit 54 are input to the microcomputer 15. In this embodiment, of these two open / close completion detection signals, The completion of driving of the SCV 10 is determined based on only one selected in advance. More specifically, when the SCV 10 is in the initial state (new) or near it, an open / close completion detection signal from the energizing current monitor circuit 51 is adopted, and when the SCV 10 is after endurance or near it, a ripple monitor is used. An open / close completion detection signal from the circuit 54 is employed.

  That is, when the SCV 10 is in the initial state, there is usually no factor (less) that hinders the driving of the SCV 10 as described above, and the motor 11 can rotate fast, so the double contact period of the commutator is short. The peak value of the ripple is also reduced. Therefore, the higher the rotation speed, the smaller the difference between the ripple peak value and the ripple detection threshold value, and there is a risk that the ripple detection (comparison by the comparator 78) in the ripple monitor circuit 54 will not be performed accurately. On the other hand, with respect to the value of the energization current Id, since the rotation speed of the motor 11 is fast in the initial state, the back electromotive force is large during rotation and the value of the energization current Id is low. When the driving of the SCV 10 is completed and the motor 11 is locked, the energization current Id increases rapidly as shown in FIG. That is, the difference between the energization current during rotation and the energization current during rotation stop (lock) is large. Therefore, in the initial state, the drive completion determination based on the open / close completion current threshold can be performed relatively easily and accurately, and the output result of the energization current monitor circuit 51 is more reliable.

  On the other hand, when the SCV 10 is a durable product after endurance, there are usually many factors that hinder the driving of the SCV 10 such as deposits, and the rotational speed of the motor 11 becomes slow, so the double contact period of the commutator is long. , Ripple also increases. Therefore, the ripple can be detected easily and accurately. On the other hand, with respect to the value of the energization current Id, since the rotation speed of the motor 11 is slow, the value of the energization current Id increases even during rotation as shown in FIG. The difference from the current-carrying current value is smaller than in the initial state.

  That is, in the initial state, the drive completion determination based on the energization current Id can be performed more easily and accurately, and in the case of a durable product, the drive completion determination based on the ripple period T2 can be performed more easily and accurately. Furthermore, as described above, since the durable product has a longer ripple cycle T2 than the initial product, it is possible to roughly distinguish the initial product or the durable product based on the ripple cycle T2.

  Therefore, in the SCV drive system of this embodiment, the microcomputer 15 detects the ripple period T2 based on the measurement value output from the timer 79 in the motor drive IC 16, and based on the detected period T2. Then, it is determined whether the product is an initial product or a durable product (by extension, which one of the energization current monitor circuit 51 and the ripple monitor circuit 54 is to be used) is selected.

  If the ripple period T2 is greater than the predetermined selection threshold T2c, it is determined that the product is a durable product or a state close thereto, and the open / close completion detection signal from the ripple monitor circuit 54 is selected. In this case, even if the driving current monitor circuit 51 determines that the driving of the SCV 10 is completed and an opening / closing completion detection signal to that effect is input to the microcomputer 15, the opening / closing completion detection signal is invalidated in the microcomputer 15. On the other hand, if the ripple period T2 is equal to or greater than the predetermined selection threshold T2c, it is determined that the product is an initial product or a state close thereto, and an open / close completion detection signal from the energization current monitor circuit 51 is selected. In this case, even if the ripple monitor circuit 54 determines that the driving of the SCV 10 is completed and an open / close completion detection signal indicating that is input to the microcomputer 15, the open / close completion detection signal is invalidated in the microcomputer 15.

  Next, the operation of the SCV drive system of the present embodiment configured as described above will be described with reference to FIGS. FIG. 5 is a time chart for explaining the operation of the SCV 10 when the SCV 10 is in an initial product or a state close thereto and the output from the energization current monitor circuit 51 is selected as the open / close completion detection signal. FIG. 6 is shown for comparison with FIG. 5, and is a time chart for explaining the operation when the drive completion of the SCV 10 after endurance is performed based on the open / close completion detection signal from the energization current monitor circuit 51. It is. FIG. 7 is a time chart for explaining the operation of the SCV 10 when the SCV 10 is in a durable product or a state close thereto and the output from the ripple monitor circuit 54 is selected as the open / close completion detection signal.

  First, the operation of the SCV 10 in an initial product or a state close thereto will be described with reference to FIG. As shown in the figure, for example, when a drive command (high level valve open command) for driving the SCV 10 in the closed position to the open position is output from the microcomputer 15, the drive logic generation circuit 37 in the motor drive IC 16 is output. In order to energize the motor 11 with DUTY 100%, a command signal is output to each of the pre-drive circuits 41 to 44. As a result, the high-side FET 31 connected to the positive terminal of the motor 11 and the low-side FET 33 connected to the negative terminal of the motor 11 are both turned on, and a current in the forward direction flows through the motor 11 at DUTY 100%.

  With this energization start, the SCV 10 gradually opens. Although an inrush current flows immediately after the start of energization, the motor 11 has a substantially constant value (but includes ripple as described above) during the subsequent rotation. The energization current value Id at this time is suppressed to some extent by the back electromotive force. Further, the temperature of the motor 11 gradually rises during energization.

  Then, when the SCV 10 is fully opened (reached to the open position) and its driving is stopped and the motor 11 is locked, the energization current of the motor 11 rapidly increases. At this time, in the conventional system described with reference to FIGS. 17 and 18, the energization current is limited so as not to exceed the current limit value (see the alternate long and short dash line in the figure). Continue energization at DUTY 100% without providing a current limit. Therefore, the energization current Id after locking exceeds the conventional current limit value and further increases. Then, when the energization current Id becomes equal to or higher than the switching completion current threshold and the output of the comparator 63 of the energization current monitor circuit 51 becomes high level, the completion of the opening operation of the SCV 10 is detected. In this embodiment, since the opening degree of the SCV 10 is not detected using the angle sensor, the energization current is not controlled until the fully opened position is reached. That is, the drive system in which the SCV 10 is normally driven from when the drive of the SCV 10 is started to when the drive is completed is a drive system that supplies an energized current without any control of the energized current. .

  The high level output from the comparator 63 is output to the microcomputer 15 as an open / close completion detection signal. When the microcomputer 15 receives the opening / closing completion detection signal from the motor driving IC 16, the microcomputer 15 determines that the opening operation is completed, and a drive command (low level signal) to stop energizing the motor 11. Is output. Thereby, the energization to the motor 11 is stopped. However, in detail, the energization current does not suddenly become zero, and a circulating current for releasing the residual energy of the motor 11 flows for a short time.

  When the motor 11 is locked, the temperature of the motor 11 also rises rapidly as the energization current suddenly increases. However, since the energization is eventually stopped by detecting the completion of the opening operation as described above, after the energization is stopped, The temperature gradually decreases. For this reason, if energization in a state limited to the current limit value as in the conventional case is continued for the lock determination period T1, the temperature continues to rise while the energization is continued. When completion is detected, energization to the motor 11 is quickly stopped, so that heat generation is reduced.

  Next, driving of the SCV 10 in a durable product or a state close thereto will be described. In the case of a durable product or a state close thereto, in this embodiment, the completion of the opening / closing of the SCV 10 is determined based on the opening / closing completion detection signal from the ripple monitor circuit 54. The operation when the completion of opening / closing is determined based on the opening / closing completion detection signal from the energization current monitor circuit 51 as in FIG. 5 will be described with reference to FIG.

  In the case of a durable product, as described above, the motor 11 rotates at a relatively low speed by a deposit or the like. Therefore, as shown in FIG. 6, the energization current Id becomes large even after rotation after the start of energization. FIG. 6 shows a case where the energizing current Id during rotation is larger than the conventional current limit value. In this way, as long as the motor 11 is rotating (that is, as long as the SCV 10 is being driven), energization at DUTY 100% is continued without limiting the energization current. Thereby, the opening speed of the SCV 10 is faster than that of the conventional system shown in FIG. 18 (see the one-dot chain line portion in FIG. 6).

  Then, when the SCV 10 is fully opened (reached to the open position) and its driving is stopped and the motor 11 is locked, the energization current Id of the motor 11 further increases. When the energization current Id becomes equal to or higher than the opening / closing completion current threshold, the output of the comparator 63 becomes high level, and the completion of the opening operation of the SCV 10 is detected. As a result, similarly to the case of FIG. 5, the microcomputer 15 outputs a drive command (low level signal) indicating that energization should be stopped, and the energization to the motor 11 is stopped.

  When the motor 11 is locked, the temperature of the motor 11 also rises rapidly as the energization current suddenly increases. However, since the energization is eventually stopped by detecting the completion of the opening operation as described above, after the energization is stopped, The temperature gradually decreases. Therefore, even in the case of a durable product, the energization is quickly stopped when the completion of the opening operation is detected without continuing energization during the fixed lock determination period T1 as in the prior art. Heat generation is reduced. In addition, when the conventional method indicated by the chain line, that is, when the current is limited and the predetermined time T1 is used as the determination criterion, as shown in the schematic graph showing the temperature rise, the heat generation is that of this embodiment. It is larger than On the other hand, in this embodiment, an open / close completion current threshold is set that can determine whether or not it is locked by the energization current itself, and until the time whether the state exceeding the open / close completion current threshold continues for a predetermined time is a determination item. Not. Therefore, it can be reliably detected at an early stage in the locked state, and heat generation can be reduced as compared with the conventional method. Furthermore, in this embodiment, the lock determination is performed only by the switching completion current threshold value.

  However, as apparent from comparison between FIG. 5 and FIG. 6, the difference between the energization current Id during rotation of the motor 11 and the open / close completion current threshold is large in the case of FIG. In the case of FIG. 6, which is a durable product or a state close thereto, the difference is small. Therefore, in the case of a durable product or a state close thereto, depending on the rotational speed of the motor 11 and the set value of the open / close completion current threshold, the difference between the energizing current Id during rotation and the open / close completion current threshold becomes very small, and the SCV 10 is driven. The completion may not be accurately determined.

  Therefore, in the present embodiment, in the case of a durable product or a state close thereto, the completion of driving of the SCV 10 is determined based on the presence or absence of a ripple included in the energization current Id. That is, the completion of driving of the SCV 10 is determined based on the open / close completion detection signal from the ripple monitor circuit 54. This will be described with reference to FIG.

  As shown in FIG. 7, when energization of the motor 11 starts and the motor 11 starts to rotate (the SCV 10 starts to open), the ripple monitor circuit 54 detects the ripple included in the energization current Id, and the ripple The period T2 is measured by the timer 79. At this time, while the motor 11 is rotating, a ripple is generated at a cycle T2 corresponding to the rotation speed, and therefore the measured value of the timer 79 is cleared every time the ripple is generated. Therefore, the measured value of the timer 79 does not exceed the opening / closing completion ripple threshold during rotation.

  When the SCV 10 reaches the open position and its driving is completed and the motor 11 is locked, the ripple is not detected. Therefore, the measured value of the timer 79 is counted up and finally becomes equal to or greater than the opening / closing completion ripple cycle threshold. When this happens, a high-level opening / closing completion detection signal is output from the timer 79 and transmitted to the microcomputer 15.

  Thereby, the microcomputer 15 determines the completion of the drive of the SCV 10 (open operation completion) and outputs a drive command (low level signal) to stop energization of the motor 11. Therefore, energization to the motor 11 is stopped.

  Up to this point, the case where the current in the forward rotation direction is supplied to the motor 11 to drive the SCV 10 to the open position has been described. However, also in the case where the SCV 10 is driven to the closed position, the energization direction to the motor 11 is the reverse rotation direction. Except for this, the drive characteristics of the SCV 10 and the energization characteristics of the motor 11 are exactly the same as in the case of driving to the open position described above.

  By the way, the energization characteristics of the motor 11 are affected by the power supply voltage Vb of the motor 11 and the temperature of the motor 11 (specifically, the temperature of the motor winding). Specifically, as the power supply voltage Vb increases, the current flowing through the motor 11 also increases and the rotation speed increases. Even if the power supply voltage Vb is constant, if the temperature of the motor 11 increases, the resistance value of the motor winding increases, the current flowing through the motor 11 decreases, and the rotation speed decreases. In particular, the SCV drive system according to the present embodiment is a system for driving the SCV 10 provided in the internal combustion engine 2 of the vehicle, and the motor 11 is also provided in the vicinity of the internal combustion engine 2. And the temperature change is severe. Therefore, in some cases, for example, the temperature becomes very high and the resistance of the motor 11 increases to reduce the energization current Id. Even if the motor 11 is locked, the energization current Id may not exceed the switching completion current threshold. . That is, if each of the threshold values is fixed to a constant value, the SCV 10 drive completion (locking of the motor 11) may not be accurately detected depending on changes in the power supply voltage Vb and the temperature.

  Therefore, in the SCV drive system of the present embodiment, the switching completion current threshold, the switching completion ripple cycle threshold, and the ripple detection threshold, and the amplification factor in the ripple amplifier circuit 53 are not fixed to a constant value, and the power supply voltage Vb The setting is appropriately changed according to the temperature of the motor 11. That is, in the microcomputer 15, the threshold values and the amplification factors are calculated to appropriate values based on the detection results from the power supply voltage detection circuit 17 and the water temperature sensor 18, respectively. The calculation results are input from the microcomputer 15 to the motor drive IC 16 through the serial input line 82 as the current threshold setting command, ripple cycle threshold setting command, ripple detection threshold setting command, and amplification factor setting command. The In this embodiment, since the temperature of the motor 11 and the temperature of the cooling water of the internal combustion engine 2 are substantially equal, instead of directly detecting the temperature of the motor 11, the temperature of the motor 11 is estimated from the temperature of the cooling water. ing.

  How the respective threshold values and amplification factors are specifically calculated will be described with reference to FIG. First, even if the power supply voltage Vb is constant, the higher the temperature of the motor 11, the greater the resistance value of the motor winding, so the energization current Id becomes smaller, and the ripple peak value accordingly decreases. When the energization current Id is small, the torque of the motor 11 is also reduced and the rotational speed is also reduced, so that the ripple cycle T2 becomes longer.

  Therefore, in this embodiment, as shown in FIG. 8A, the higher the water temperature detected by the water temperature sensor 18 (that is, the higher the temperature of the motor 11), the higher the switching completion current threshold and the ripple detection threshold. The opening / closing completion ripple cycle threshold and the amplification factor are set to be low.

  On the other hand, even if the temperature of the motor 11 is constant, the higher the power supply voltage Vb, the larger the energizing current Id of the motor 11 and the higher the peak value of the ripple. When the energization current Id is large, the torque of the motor 11 is also increased and the rotation speed is increased, so that the ripple period T2 is shortened.

  Therefore, in the present embodiment, as shown in FIG. 8B, the higher the power supply voltage Vb detected by the power supply voltage detection circuit 17, the higher the switching completion current threshold and the ripple detection threshold, and the switching completion ripple cycle threshold. The amplification factor is set to be low.

  Although FIG. 8 shows an example in which each threshold value and amplification factor are linearly changed with respect to the water temperature and the power supply voltage, this is only an example and may be changed nonlinearly. In addition, the calculation of each threshold value and amplification factor by the microcomputer 15 may be performed by executing a numerical calculation having a tendency shown in FIG. 8 with respect to the water temperature and the power supply voltage. Alternatively, an appropriate threshold value / amplification factor corresponding to the value of the water temperature or the power supply voltage is obtained in advance by experiments, etc., and stored (mapped) in the memory, and the water temperature or power supply voltage at that time is obtained. A corresponding value may be used.

  In short, an appropriate value corresponding to the water temperature and power supply voltage at that time is calculated so that the energization current monitoring circuit 51 can accurately detect the completion of switching of the SCV 10 if the switching completion current threshold value, and the switching completion ripple cycle threshold value is calculated. If there is a ripple detection circuit 54 (specifically, timer 79), an appropriate value corresponding to the water temperature and power supply voltage at that time is calculated so that the completion of opening and closing of the SCV 10 can be accurately detected. In order for the circuit 54 (more specifically, the comparator 78) to accurately detect the ripple, an appropriate value corresponding to the water temperature and the power supply voltage at that time is calculated. The water temperature and power supply at that time are amplified so as to be amplified to an appropriate level (a value that can reliably detect ripples in the subsequent ripple monitor circuit 54). So that the appropriate value for the pressure is calculated, it is preferable to be constituted of a microcomputer 15.

  Furthermore, in the present embodiment, various threshold values and amplification factors calculated as described above are corrected and calculated based on the energization current Id. This is because even if the water temperature and the power supply voltage Vb are constant, there may be a difference in energization characteristics depending on individual differences of the motor 11. For example, even if the motor 11 is designed in the same way, due to manufacturing tolerances and other subtle individual differences (electrical or mechanical individual differences) The speed may be different. In addition, if an error occurs in the calculation of each threshold value in the microcomputer 15, there is a possibility that an appropriate threshold value calculation according to the water temperature or the power supply voltage Vb may not be performed.

  Therefore, in the present embodiment, the microcomputer 15 corrects each threshold value and amplification factor calculated based on the water temperature and the power supply voltage Vb based on the actual energization current Id detected by the motor driving IC 16. Like to do. This correction calculation is performed every time energization of the motor 11 is started. However, when correction is not necessary, that is, if the calculated threshold value or amplification factor is an appropriate value, actual correction is performed. The calculation result is used as it is. That is, the calculation result is compared with the actual value of the energization current Id, and correction is actually performed only when correction is necessary.

  This correction calculation is performed so that each of the threshold values and the amplification factor is set to appropriate values, and further, the completion of driving of the SCV 10 and the lock of the motor 11 can be accurately detected. The following calculation is performed.

  For example, when the water temperature is high, the actually detected energization current Id is larger than the value assumed in the design even though the switching completion current threshold is calculated to a lower value according to the water temperature. It is expected that the resistance value of the motor winding is lower than the design value. In that case, the calculated switching completion current threshold value is corrected to a higher value.

  Further, when the power supply voltage Vb is high, the actually detected energization current Id is higher than the value assumed in the design even though the switching completion current threshold is calculated to a higher value according to the power supply voltage Vb. If it is smaller, the resistance value of the motor winding is larger than the design value, or an abnormality of the power supply voltage detection circuit 17 is expected. In that case, the calculated switching completion current threshold value is corrected to a lower value.

  Further, when the power supply voltage Vb is low (that is, the rotation speed of the motor 11 should be slow), the open / close completion ripple cycle threshold value is calculated to a small value due to an error in the calculation program in the microcomputer 15 or the like. Is corrected based on the actual value of the energization current Id (small value corresponding to the power supply voltage Vb) to a larger value for the calculated opening / closing completion ripple cycle threshold.

  Next, various processes executed by the microcomputer 15 will be described. FIG. 9 illustrates a determination for selecting whether to determine whether the SCV 10 has been opened or closed based on an opening / closing completion detection signal from the energization current monitor circuit 51 or based on an opening / closing completion detection signal from the ripple monitor circuit 54. It is a flowchart showing a selection process. This process is executed every time (or periodically) every time the motor 11 is driven at DUTY 100%.

  When this determination / selection process is started by starting the driving of the motor 11, first, a ripple period T2 is acquired based on the measurement value output from the timer 79 of the ripple monitor circuit 54 (S110). As described above, the measurement result (elapsed time) by the timer 79 is input to the microcomputer 15 at any time.

  Note that it is only necessary to appropriately determine at which timing the period T2 is acquired after the start of energization. For example, the ripple period T2 in a state where the period T2 has settled in a substantially constant state after the inrush current flows may be acquired. The period T2 may be acquired at a plurality of timings after the start of energization, and the average value thereof may be taken.

  After the ripple period T2 is acquired, it is determined whether the period T2 is equal to or less than a preset selection threshold T2c (S120). If it is equal to or less than the selection threshold T2c (S120: YES), it is set to the valve open / closed detection mode based on the energization current value Id as being an initial product or a state close thereto (S130). That is, based on the opening / closing completion detection signal from the energization current monitor circuit 51, the completion of the opening / closing of the SCV 10 is determined.

  On the other hand, when the ripple period T2 is larger than the selection threshold T2c (S120: NO), the valve opening / closing detection mode based on the ripple period T2 is set as a durable product or a state close thereto (S140). That is, the completion of opening / closing of the SCV 10 is determined based on the opening / closing completion detection signal from the ripple monitor circuit 54.

  Next, the energization drive process executed when the start condition (details are omitted) of the opening operation or the closing operation of the SCV 10 is satisfied and energization of the motor 11 is started will be described based on FIG. When driving of the SCV 10 is started, first, various threshold values and amplification factors are calculated based on the power supply voltage Vb and the water temperature (S210). Various setting commands (current threshold setting command, ripple cycle threshold setting command, ripple detection threshold setting command, amplification factor setting command) corresponding to the calculation result are output to the motor driving IC 16 (S220). After that, a DUTY 100% drive command (valve opening command; see FIGS. 5 and 6) is output to the motor drive IC 16, thereby starting energization of the motor 11 at DUTY 100% and starting driving the SCV 10. (S230).

  When energization to the motor 11 is started, it is determined whether or not the various thresholds and amplification factors set in S210 are appropriate values based on the actual energization current value Id input from the motor driving IC. (S240). At this time, if it is not appropriate, the correction calculation as described above is performed and a setting command corresponding to the new value after the correction is output to the motor drive IC 16. Not done.

  Then, after energization is started, it is determined whether an open / close completion detection signal has been received from the motor driving IC 16 (S250). Here, either the open / close completion detection signal from the energization current monitor circuit 51 or the open / close completion detection signal from the ripple monitor circuit 54 is received as one of the open / close completion detection signals selected in the determination selection process of FIG. If this is the case (S250: YES), it is determined that the opening / closing drive of the SCV 10 has been completed and the motor 11 has been locked, and energization of the motor 11 is stopped (S260). That is, the drive command is set to a low level.

  In the process of FIG. 10, the correction calculation (S240) is periodically performed after the start of energization of the motor 11 until the completion of opening and closing is detected. However, this correction calculation is performed only once after the start of energization. You may make it perform. Alternatively, it may be performed only several times.

  In the SCV drive system of this embodiment described in detail above, when the SCV 10 is driven to the open position or the closed position, the motor 11 is energized at DUTY 100% until the drive is completed. That is, the motor 11 is continuously energized without performing the current limitation such as setting the upper limit value of the energization current and limiting it so as not to exceed the upper limit value as in the prior art. When the motor 11 is locked due to the completion of driving of the SCV 10, the energization current Id rises rapidly and the ripple of the energization current Id disappears.

  Therefore, in the motor drive IC 16, the energization current monitor circuit 51 detects the lock of the motor 11 (that is, the completion of driving of the SCV 10) and outputs an open / close completion detection signal when the energization current Id becomes equal to or greater than the open / close completion current threshold. To do. On the other hand, the ripple monitor circuit 54 detects the lock of the motor 11 and outputs an opening / closing completion detection signal when the ripple is no longer detected, that is, when the measurement result of the timer 79 becomes equal to or greater than the opening / closing completion ripple cycle threshold. . Then, when any one of these open / close completion detection signals is received, the microcomputer 15 determines the completion of driving of the SCV 10 and stops energization of the motor 11.

  Therefore, according to the SCV drive system of the present embodiment, since the motor 11 is energized at DUTY 100% while the SCV 10 is driven, the drive response of the SCV 10 is improved. Further, when it is determined that the drive of the SCV 10 is completed, the energization of the motor 11 is stopped, so that the conventional problem that the lock current continues to flow after the drive is completed (after the motor is locked) is solved. Heat generation of the IC 16 can be reduced. In addition, since it is not necessary to separately provide an angle sensor or the like for determining whether the SCV 10 has been driven, it is possible to improve the durability and reliability of the motor driving IC 16 and the motor 11 while suppressing an increase in cost. It becomes.

  Further, when the SCV 10 is an initial product or a state close thereto, the completion of driving of the SCV 10 is determined based on an open / close completion detection signal from the energization current monitor circuit 51. When the SCV 10 is a durable product or a state close thereto, the ripple monitor circuit 54 Since the completion of driving of the SCV 10 is determined based on the opening / closing completion detection signal from the above, the completion of driving can be accurately determined regardless of the state of the SCV 10 (initial product or durable product).

  Furthermore, various threshold values and amplification factors are not fixed to constant values, and appropriate values corresponding to the power supply voltage Vb and the water temperature are obtained by calculation. In addition, a correction calculation is performed on the calculation result as necessary based on the actual energization current Id. Therefore, various threshold values and amplification factors are set to more appropriate values in the motor driving IC 16, so that the determination of the lock of the motor 11 and the determination of the completion of driving of the SCV 10 can be performed more accurately.

  Furthermore, since various setting commands corresponding to the above threshold values and amplification factors from the microcomputer 15 to the motor driving IC 16 are input in the serial data format through the serial input line 82 as a common transmission path, the microcomputer The wiring between the IC 15 and the motor driving IC 16 can be reduced and the number of ports of the microcomputer 15 can be reduced, so that the entire system can be reduced in size and cost.

  In the present embodiment, the microcomputer 15 corresponds to the control means, determination selection means, and threshold value command output means of the present invention, and the power supply voltage detection circuit 17 and the water temperature sensor 18 are both environmental parameter detection means of the present invention. The comparator 63 in the energization current monitor circuit 51 corresponds to the first drive completion determination unit of the present invention, and the timer 79 in the ripple monitor circuit 54 includes the measurement unit of the present invention, the second drive completion determination unit, and The comparator 78 in the ripple monitor circuit 54 corresponds to the second threshold setting means, the ripple generation determination means of the present invention, and the AC coupling 52 corresponds to the DC component removal means of the present invention. The comparator 63 in the energization current monitor circuit 51 and the timer 79 in the ripple monitor circuit 54 together with the serial I / F 46 constitute drive completion notification means of the present invention. The drive logic generation circuit 37, the predrive circuits 41 to 44, and the FETs 31 to 34 constitute drive means of the present invention. The current threshold setting resistor 61 and the resistor 62 in the energization current monitor circuit 51 constitute the present invention. The first threshold setting means is configured, and the ripple detection threshold setting resistor 76 and the resistor 77 in the ripple monitor circuit 54 constitute the third threshold setting means of the present invention.

  Moreover, the determination selection process of FIG. 9 is equivalent to the process which the determination selection means of this invention performs. Further, the processing of S210 to S220 in the energization driving processing of FIG. 10 corresponds to the processing executed by each threshold command output means of the present invention.

[Second Embodiment]
Next, the SCV drive system of the second embodiment will be described. The SCV drive system of this embodiment is different from the SCV drive system of the first embodiment in that the motor drive IC is stopped after the drive completion of the SCV 10 (lock of the motor 11) is detected in the motor drive IC. The other hardware configurations and system operations are exactly the same as those in the first embodiment. Therefore, the following description will be focused on differences from the first embodiment.

  FIG. 2 shows a configuration of the electronic control device 100 in the SCV drive system of the present embodiment. The electronic control device 100 of this embodiment includes an open / close completion detection unit 87 and a stop request generation unit 86 in the motor drive IC 91.

  Both the opening / closing completion detection signal from the energization current monitor circuit 51 and the opening / closing completion detection signal from the ripple monitor circuit 54 are input to the opening / closing completion detector 87. Then, the opening / closing completion detection unit 87 outputs only one of these opening / closing completion detection signals set by a command from the microcomputer 90 to the stop request generation unit 86 as a valid signal.

  That is, in the microcomputer 90, the determination selection process shown in FIG. 9 is executed as in the first embodiment. Then, a processing result (selection result) by the determination selection process is input to the open / close completion detection unit 87 via the serial input line 82 and the serial I / F 93. For this reason, the open / close completion detection unit 87 treats only one of the selected open / close completion detection signals as a valid signal according to the selection result input from the microcomputer 90.

  Therefore, for example, when the SCV 10 is an initial product and an instruction is received from the microcomputer 90 to select the open / close completion detection signal from the energization current monitor circuit 51, the output of the comparator 63 in the energization current monitor circuit 51 becomes high level. When this occurs, an open / close completion detection signal, which is a high level signal, is output to the stop request generator 86. Conversely, when the SCV 10 is a durable product and receives an instruction from the microcomputer 90 to select the opening / closing completion detection signal from the ripple monitor circuit 54, a high-level opening / closing completion detection signal is output from the timer 79 in the ripple monitor circuit 54. When output, the open / close completion detection signal is output to the stop request generation unit 86.

  The stop request generation unit 86 serving as an energization suppression requesting unit stops the drive logic generation circuit 92 from stopping energization to the motor 11 when the open / close completion detection signal is input from the open / close completion detection unit 87. Output the request. When there is a stop request from the stop request generator 86, the drive logic generation circuit 92 stops energization of the motor 11 regardless of the presence or absence of a drive command from the microcomputer 90. In other words, in the present embodiment, after the driving of the SCV 10 is completed, the energization stop of the motor 11 is not performed based on the drive command from the microcomputer 90, but from the stop request generation unit 86 in the motor drive IC 91 to the last. This is done in hardware by a stop request.

  At the start of driving the SCV 10, the microcomputer 90 outputs a drive command for energizing at DUTY 100%, as with the microcomputer 15 of the first embodiment, but the drive command is a fixed period T1 (conventional lock determination period T1). Equivalent, see FIG. That is, even if the driving of the SCV 10 is completed and the motor 11 is locked, the high-level driving command is continuously output until the period T1 elapses. This is because the motor drive IC 91 stops the energization of the motor 11 even if the stop request generator 86 does not output a stop request due to some abnormality or the like even though the drive of the SCV 10 is completed. To be able to do that. Thus, by setting the drive command to the low level after the lapse of the predetermined period T1, the SCV 10 can be reliably driven and the energization can be stopped even in the case of an abnormality such that the stop request is not output.

  Next, the operation of the SCV 10 of this embodiment will be described with reference to FIGS. First, FIG. 12 is a flowchart showing an operation when the SCV 10 is an initial product or a state close thereto, and an instruction is received from the microcomputer 90 to select an open / close completion detection signal from the energization current monitor circuit 51. In this figure, after the start of energization, the operation from the completion of the driving of the SCV 10 until the energization current Id becomes equal to or greater than the switching completion current threshold is the same as the operation of FIG. 5 described in the first embodiment.

  In the present embodiment, when the energization current becomes equal to or higher than the open / close completion current threshold, the energization current monitor circuit 51 outputs an open / close completion detection signal (a high level signal from the comparator 63). High level signal) is output. The energization to the motor 11 is stopped by this stop request.

  Therefore, also in this embodiment, as in FIG. 5 in the first embodiment, when the driving of the SCV 10 is completed, the energization to the motor 11 is immediately stopped, and the heat generation of the motor 11 and the motor driving IC 91 is suppressed to the minimum. The Rukoto.

  FIG. 13 is a flowchart showing an operation when the SCV 10 is in a durable product or a state close thereto and receives an instruction from the microcomputer 90 to select an open / close completion detection signal from the ripple monitor circuit 54. In this figure, after the start of energization, the operation until the measured value of the timer 79 becomes equal to or greater than the open / close completion ripple cycle threshold after the driving of the SCV 10 is completed is the same as the operation of FIG. 7 described in the first embodiment. In addition, the one-dot chain line part shows the case where lock determination is performed using the determination time T1 while performing current limiting in the conventional manner, as in FIG.

  In the present embodiment, when the measured value of the timer 79 becomes equal to or greater than the opening / closing completion ripple cycle threshold, an opening / closing completion detection signal (a high level signal from the timer 79) is output from the ripple monitor circuit 54. A stop request (high level signal) is output. The energization to the motor 11 is stopped by this stop request.

  Therefore, even after endurance, as in FIG. 7 in the first embodiment, when the driving of the SCV 10 is completed, the energization to the motor 11 is immediately stopped, and the heat generation of the motor 11 and the motor driving IC 91 is suppressed to the minimum. It will be.

  Thus, also in this embodiment, when the drive of the SCV 10 is completed, the energization to the motor 11 is quickly and reliably stopped. However, in the case of the first embodiment, when the driving of the SCV 10 is completed and an opening / closing completion detection signal is output from any of the monitor circuits, it is once transmitted to the microcomputer 15 and the microcomputer 15 indicates that the driving is completed. Is judged. Thereafter, a drive command (low level signal) indicating that energization should be stopped is output from the microcomputer 15, and energization to the motor 11 is stopped in the motor drive IC 16 only after receiving this. That is, the operation of the first embodiment is that the motor drive IC 16 once notifies the microcomputer 15 that the drive is completed, and the microcomputer 15 that has received the notification issues an energization stop command to the motor drive IC 16. is there.

  On the other hand, in this embodiment, when the motor driving IC 91 detects the completion of driving of the SCV 10 (locking of the motor 11), a stop request is generated in the motor driving IC 91, and the microcomputer 90 outputs a high level. Even if the drive command is output, the energization to the motor 11 is stopped by the stop request. Therefore, compared with the said 1st Embodiment, the direction of this embodiment can stop the electricity supply to the motor 11 more rapidly, and can suppress the heat_generation | fever of the motor 11 and the motor drive IC 16 lower by that much. .

  Next, the energization drive process executed by the microcomputer 90 of this embodiment will be described based on FIG. In the energization drive process of FIG. 14, the processes of S310 to S340 are exactly the same as S210 to S240 in the energization drive process of the first embodiment shown in FIG. 10, and the process of S360 of FIG. 14 is the same as S260 of FIG. The same. 14 is different from FIG. 10 in the process of S350.

  That is, in the first embodiment, after the start of energization at DUTY 100%, when the open / close completion detection signal is input from the motor drive IC 16, the drive command is set to the low level to stop the energization. In the embodiment, as shown in FIG. 14, after the start of energization at DUTY 100%, a high level drive command is continuously output until a predetermined period T1 elapses regardless of the drive state of the SCV 10 (S350). Then, after a certain period T1 has elapsed, the drive command is set to a low level (S360).

[Modification]
Although the embodiments of the present invention have been described above, the present invention is such that an object driven by a motor such as a valve is forcibly positioned and driven by an external factor such as a fully open position or a fully closed position. The present invention is characterized by the motor drive device that is to be detected. In the above embodiment, a sensor that detects the operating position of a driven part such as a rotation angle sensor by using threshold values (open / close completion current threshold value, open / close completion ripple cycle threshold value, etc.) that can determine the lock state based on the energization current For example, a forcibly positioned drive completion state such as a fully open position or a fully closed position can be detected without using the above. In addition, since such a sensor is not used, the control of the energized current is not performed at all during the driving period from the start of driving of a driven member such as a valve to the completion, that is, the open loop control. It can be said that this is a feature of this embodiment.

And embodiment of this invention is not limited to each said embodiment at all, and it cannot be overemphasized that various forms can be taken as long as it belongs to the technical scope of this invention.
For example, in the above embodiment, the energization to the motor 11 is stopped after the driving of the SCV 10 is completed. However, the energization may be continued at a low current value in order to maintain the driving completion state. That is, after the energization of the motor 11 is stopped by the completion of driving of the SCV 10, depending on the structure of the SCV 10, the driving completion state may not be maintained due to external vibration or load. In particular, since a valve provided in an air intake path in an internal combustion engine of a vehicle, such as SCV10, receives pressure from inflowing air, there is a risk that the open / close state of the valve may not be maintained if the energization is stopped depending on the valve open / close mechanism. is there. In such a case, after the driving is completed, it is preferable not to completely stop the energization of the motor but to continue the energization so that the driving completion state is maintained. Of course, it is desirable to energize at the minimum current value necessary to maintain the drive completion state.

  In other words, whether to stop energization of the motor after the driving of the driving target such as the SCV 10 is completed or whether to supply a current for maintaining the state is appropriately determined according to the system configuration, required specifications, and the like. Just decide.

  In the above embodiment, the switching completion detection signal from the energization current monitor circuit 51 (that is, the switching completion detection result of the SCV 10 based on the energization current value Id) and the switching completion detection signal from the ripple monitor circuit 54 (that is, whether or not there is a ripple) The completion of driving of the SCV 10 is determined based on either one of the SCV 10 according to the state of the SCV 10 based on the cycle), but both may be used together. For example, when any one of the opening / closing completion detection signals is output, it may be determined that the SCV 10 has been driven. Further, for example, the completion of driving of the SCV 10 may be determined only when both opening / closing completion detection signals are output.

  Further, as to which of the above open / close completion detection signals is selected, it is only an example to determine whether it is an initial product or a durable product as in the above embodiment, and it is selected based on various criteria. be able to.

  In the first embodiment, the system in which the microcomputer 15 controls one motor driving IC 16 has been described. However, as shown in FIG. 15, one microcomputer has a plurality of motor driving ICs (motor driving circuits). You may make it control.

  That is, as shown in FIG. 15, the microcomputer 120 controls a plurality of motor drive circuits 130, 140,... For driving other different driving objects in addition to the motor driving IC 16. The microcomputer 120, the motor driving IC 16 and the motor driving circuits 130, 140,... Are connected by a common serial communication line. Specifically, a clock line 81 is connected for transmission of the clock signal SCK from the microcomputer 120 to the motor driving IC 16 and the motor driving circuits 130, 140,..., And serial data (input data) from the microcomputer 120 is also used. The serial input line 82 is connected for transmission (SDI), and the serial output line 83 is connected for transmission of serial data (output data SDO) from the motor driving IC 16 and the motor driving circuits 130, 140,. Has been.

  As described above, it is possible to control a plurality of motor drive ICs (motor drive circuits) with a single microcomputer in the same manner as in the above embodiments. In this case, as shown in FIG. By transmitting and receiving in a data format and sharing the transmission path, the entire system can be reduced in size and cost.

  In the above embodiment, instead of directly detecting the temperature of the motor 11, the coolant temperature of the internal combustion engine 2 is detected and used as the temperature of the motor 11. The temperature of the motor 11 may be directly detected by attaching a temperature sensor directly to the body or attaching a temperature sensor near the motor winding in the motor.

  In the above embodiment, various threshold values and amplification factors are calculated based on the power supply voltage Vb and the water temperature as environmental parameters. However, the power supply voltage Vb and the water temperature are merely examples of environmental parameters, Various threshold values and amplification factors may be calculated based on parameters (parameters that act directly or indirectly on the motor separately from the motor load and affect the current-carrying current characteristics).

  Further, in the above embodiment, the case where the present invention is applied to the SCV drive system has been described as an example. However, in addition to the drive of the SCV 10, for example, the opening / closing drive of the intake pipe length switching valve 9 or the EGR valve 13 is driven. The present invention may be applied to the opening / closing drive as in the above embodiments. That is, the present invention can be applied to any system that is configured to drive an object to be driven to a predetermined position / state by a motor and forcibly lock the rotation of the motor when the driving is completed.

It is a schematic block diagram of an SCV drive system. It is explanatory drawing which shows the structure of the electronic control apparatus of 1st Embodiment. It is explanatory drawing for demonstrating the contact state of the brush and commutator in a motor. It is explanatory drawing for demonstrating that a ripple is contained in the energization current during motor rotation. It is a time chart which shows operation | movement of the SCV drive system (initial product or a state close | similar to it) of 1st Embodiment. It is a time chart which shows operation | movement at the time of performing the drive completion detection based on the value of an energization current with respect to the durable goods or the SCV drive system of the state close | similar to it. It is a time chart which shows operation | movement of the SCV drive system (durable product or a state close | similar to it) of 1st Embodiment. It is a graph which shows the change of each threshold value and amplification factor with respect to water temperature and power supply voltage. It is a flowchart which shows determination selection processing. It is a flowchart which shows the electricity supply drive process of 1st Embodiment. It is explanatory drawing which shows the structure of the electronic control apparatus of 2nd Embodiment. It is a time chart which shows operation | movement of the SCV drive system (initial product or a state close | similar to it) of 2nd Embodiment. It is a time chart which shows operation | movement of the SCV drive system (durable product or a state close | similar to it) of 2nd Embodiment. It is a flowchart which shows the electricity supply drive process of 2nd Embodiment. It is explanatory drawing which shows the state by which several IC for motor drive (motor drive circuit) was connected to one microcomputer. It is explanatory drawing for demonstrating the opening / closing operation | movement of SCV. It is a time chart which shows operation | movement of the conventional SCV drive system (initial product). It is a time chart which shows operation | movement of the conventional SCV drive system (durable product).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,100 ... Electronic control unit, 2 ... Internal combustion engine, 5 ... Intake pipe, 5a ... 1st intake port, 5b ... 2nd intake port, 5c ... Auxiliary intake pipe, 7 ... Exhaust pipe, 8 ... Throttle valve, 9 ... Intake pipe length switching valve, 10 ... SCV (swirl control valve), 11 ... motor, 12 ... EGR pipe, 13 ... EGR valve, 15, 90, 120 ... microcomputer, 16, 91 ... IC for motor drive, 17 ... power supply voltage detection Circuit, 18 ... Water temperature sensor, 20 ... Rotating shaft, 21 ... Regulating protrusion, 23 ... Deposit, 25,26 ... Brush, 27a, 27b, 27c ... Commutator, 28ab, 28bc, 28ca ... Motor winding, 29 ... Rotation Axis, 30 ... A / D conversion circuit, 31-34 ... FET, 36 ... Current detection circuit, 37,92 ... Drive logic generation circuit, 41-44 ... Pre-drive circuit, 46,93 ... 51 ... energization current monitor circuit, 52 ... AC coupling, 53 ... ripple amplifier circuit, 54 ... ripple monitor circuit, 61 ... current threshold setting resistor, 62, 77 ... resistor, 63, 78 ... comparator, 66 ... Coupling capacitor, 71 ... Input resistance, 72 ... Feedback resistor, 73 ... Operational amplifier, 76 ... Ripple detection threshold setting resistor, 79 ... Timer, 81 ... Clock line, 82 ... Serial input line, 83 ... Serial output line, 86 ... Stop request generation unit, 87 ... Opening / closing completion detection unit, 92 ... Drive logic generation circuit, 130, 140 ... Motor drive circuit

Claims (23)

An in-vehicle motor drive device for controlling the drive of a driven part driven by a motor so as to be forcibly positioned at a predetermined position due to an external factor,
Drive means for driving the motor by energizing the motor based on an input drive command;
Control means for outputting the drive command for controlling the drive of the driven part to the drive means;
Current detection means for detecting an energization current of the motor;
A current threshold set to a value for discriminating a lock current flowing through the motor when the driven unit is forcibly positioned by the external factor is used to determine the completion of driving of the driven unit. First threshold value setting means set as a determination criterion;
First driving completion determination means for determining that driving of the driven part is completed when an energization current detected by the current detection means exceeds a current threshold set in the first threshold setting means; ,
With
The control means continuously energizes the motor from the start of driving of the driven part until at least the driving of the driven part is completed by being forcedly positioned by the external factor. The continuous energization command that is the drive command is output to the drive means,
When the driving means determines that the driving of the driven part is completed by the first driving completion determination means after the start of energization to the motor based on the continuous energization command from the control means, An on-vehicle motor drive device characterized in that energization to a motor is stopped or reduced. An in-vehicle motor drive device for controlling the drive of a driven part driven by a motor so as to be forcibly positioned at a predetermined position due to an external factor,
The motor has a commutator and a brush that is in sliding contact with the commutator, and is driven by a DC power source supplied from the outside through the brush,
A driven part driven by the motor;
Drive means for driving the motor by energizing the motor based on an input drive command;
Control means for outputting the drive command for controlling the drive of the driven part to the drive means;
Current detection means for detecting an energization current of the motor;
A second threshold value setting means in which a ripple cycle threshold value is set as a criterion for determining completion of driving of the driven part;
When the period of the ripple included in the energization current detected by the current detection unit exceeds the ripple cycle threshold set in the second threshold setting unit, it is determined that the driving of the driven part is completed. 2 driving completion judging means;
With
The control means continuously energizes the motor from the start of driving of the driven part until at least the driving of the driven part is completed by being forcedly positioned by the external factor. The continuous energization command that is the drive command is output to the drive means,
When the driving means determines that the driving of the driven part is completed by the second driving completion determining means after the start of energization of the motor based on the continuous energization command from the control means, An on-vehicle motor drive device characterized in that energization to a motor is stopped or reduced. The in-vehicle motor drive device according to claim 2,
DC component removing means for removing a DC component from the energized current detected by the current detecting means;
A third threshold setting means in which a ripple detection threshold is set as a criterion for determining the occurrence of the ripple;
A ripple generation determination unit that determines that the ripple has occurred when the energization current after the DC component removal by the DC component removal unit exceeds the ripple detection threshold set in the third threshold setting unit;
Each time the ripple occurrence determination means determines that the ripple has occurred, a measurement means that measures the elapsed time after the determination as the period of the ripple;
With
The second drive completion determination unit determines that the drive of the driven unit is completed when the elapsed time measured by the measurement unit exceeds the ripple cycle threshold. Motor drive device. The in-vehicle motor drive device according to claim 2, further comprising:
A current threshold set to a value for discriminating a lock current flowing through the motor when the driven unit is forcibly positioned by the external factor is used to determine the completion of driving of the driven unit. First threshold value setting means set as a determination criterion;
First driving completion determination means for determining that driving of the driven part is completed when an energization current detected by the current detection means exceeds a current threshold set in the first threshold setting means; ,
As a determination criterion for the timing at which energization of the motor by the driving unit is stopped or reduced, either the determination result by the first drive completion determination unit or the determination result by the second drive completion determination unit is used. Determination selection means to select;
With
The driving means stops or reduces the energization of the motor when the driving completion judging means selected by the judgment selecting means determines that the driven part has been driven. In-vehicle motor drive device. The on-vehicle motor drive device according to claim 4,
The determination selection unit compares the ripple period with a preset selection threshold value. If the comparison result shows that the ripple period is larger than the selection threshold value, the determination result by the second drive completion determination unit is obtained. The vehicle-mounted motor drive device characterized by selecting and selecting a determination result by the first drive completion determination means when the period of the ripple is equal to or less than the selection threshold. The on-vehicle motor drive device according to any one of claims 1, 4 and 5,
Environmental parameter detection means for detecting environmental parameters that act directly or indirectly on the motor separately from the load of the motor and affect the current-carrying current characteristics of the motor;
Based on the environmental parameter detected by the environmental parameter detecting means, the current threshold value is calculated so that the driving completion of the driven part is accurately determined, and a first threshold value command corresponding to the calculation result is calculated. First threshold value command output means for outputting to one threshold value setting means;
With
The on-vehicle motor drive device characterized in that the first threshold value setting means sets the current threshold value in accordance with the first threshold value command from the first threshold value command output means. The in-vehicle motor drive device according to claim 6,
The environmental parameter detection means detects the temperature of the motor as the environmental parameter directly or indirectly,
The first threshold command output means calculates the current threshold so that the value of the current threshold decreases as the temperature of the motor detected by the environmental parameter detection means increases. Motor drive device. The in-vehicle motor drive device according to claim 6,
The environmental parameter detection means detects a power supply voltage supplied to the motor as the environmental parameter,
The in-vehicle motor characterized in that the first threshold command output means calculates the current threshold so that the value of the current threshold decreases as the power supply voltage detected by the environmental parameter detection means decreases. Drive device. An in-vehicle motor drive device according to any one of claims 2 to 5,
Environmental parameter detection means for detecting environmental parameters that act directly or indirectly on the motor separately from the load of the motor and affect the current-carrying current characteristics of the motor;
Based on the environmental parameter detected by the environmental parameter detecting means, the ripple period threshold value is calculated so that the driving completion of the driven part is accurately determined, and a second threshold value command according to the calculation result is calculated. Second threshold command output means for outputting to the second threshold setting means;
With
The on-vehicle motor drive device, wherein the second threshold value setting means sets the ripple cycle threshold value according to the second threshold value command from the second threshold value command output means. The in-vehicle motor drive device according to claim 9,
The environmental parameter detection means detects the temperature of the motor as the environmental parameter directly or indirectly,
The second threshold value command output means calculates the ripple period threshold value so that the value of the ripple period threshold value increases as the motor temperature detected by the environmental parameter detection means increases. In-vehicle motor drive device. The in-vehicle motor drive device according to claim 9,
The environmental parameter detection means detects a power supply voltage supplied to the motor as the environmental parameter,
The second threshold command output means calculates the ripple period threshold value so that the value of the ripple period threshold value increases as the power supply voltage detected by the environmental parameter detection means decreases. Motor drive device. The in-vehicle motor drive device according to claim 3,
Environmental parameter detection means for detecting environmental parameters that act directly or indirectly on the motor separately from the load of the motor and affect the current-carrying current characteristics of the motor;
Based on the environmental parameter detected by the environmental parameter detecting means, the ripple detection threshold value is calculated so that the period of the ripple is accurately detected, and a third threshold value command corresponding to the calculation result is calculated. Third threshold command output means for outputting to the threshold setting means;
With
The on-vehicle motor drive device characterized in that the third threshold setting means sets the ripple detection threshold according to the third threshold command from the third threshold command output means. The in-vehicle motor drive device according to claim 12,
The environmental parameter detection means detects the temperature of the motor as the environmental parameter directly or indirectly,
The third threshold value command output means calculates the ripple detection threshold value so that the value of the ripple detection threshold value decreases as the temperature of the motor detected by the environmental parameter detection means increases. In-vehicle motor drive device. The in-vehicle motor drive device according to claim 12,
The environmental parameter detection means detects a power supply voltage supplied to the motor as the environmental parameter,
The third threshold value command output means calculates the ripple detection threshold value so that the value of the ripple detection threshold value decreases as the power supply voltage detected by the environmental parameter detection means decreases. Motor drive device. It is a vehicle-mounted motor drive device in any one of Claims 6-14,
A threshold correction unit that corrects the calculation result of the threshold by the threshold command output unit based on the value of the energization current of the motor detected by the current detection unit;
The on-vehicle motor drive device characterized in that the threshold command output means outputs the threshold command corresponding to the threshold value corrected by the threshold correction means to the corresponding threshold setting means. The in-vehicle motor drive device according to any one of claims 1 to 15,
The drive unit, the threshold setting unit, and the drive completion determination unit are all formed in the same semiconductor integrated circuit. It is a vehicle-mounted motor drive device in any one of Claims 6-15,
The drive means, the threshold value setting means, and the drive completion determination means are all formed in the same semiconductor integrated circuit,
The semiconductor integrated circuit further includes serial communication means for performing serial communication with the outside.
The on-vehicle motor drive device, wherein the threshold setting unit receives the threshold command transmitted from the corresponding threshold command output unit in a serial data format via the serial communication unit. The in-vehicle motor drive device according to claim 15,
The drive means, the current detection means, the threshold value setting means, and the drive completion determination means are all formed in the same semiconductor integrated circuit, and the energization current of the motor detected by the current detection means is an analog value. Is configured to be output to the outside of the semiconductor integrated circuit,
Furthermore, A / D conversion means for receiving the value of the energization current output from the semiconductor integrated circuit and converting it into digital data is provided,
The on-vehicle motor drive device, wherein the threshold correction unit performs the correction based on the value of the energized current after conversion by the A / D conversion unit. The in-vehicle motor drive device according to claim 17 or 18,
A plurality of types of the semiconductor integrated circuit are provided,
The threshold command output means individually transmits the threshold command according to the calculation of the corresponding threshold value and the calculation result for each semiconductor integrated circuit,
Transmission of the threshold command from the threshold command output means to each semiconductor integrated circuit is performed using a common transmission line in a serial data format. The vehicle-mounted motor drive device according to any one of claims 1 to 19,
An energization suppression requesting unit that requests the driving unit to stop or reduce energization of the motor when the driving completion determining unit determines that the driving of the driven unit is completed;
The drive unit stops or reduces the energization to the motor regardless of the content of the drive command from the control unit when the request is made from the energization suppression request unit. Drive device. The vehicle-mounted motor drive device according to any one of claims 1 to 19,
Drive completion notifying means for notifying the control means to that effect when the drive completion determination means determines the drive completion of the driven part;
When the notification is received from the drive completion notification unit, the control unit outputs an energization suppression command that is the drive command for stopping or reducing energization to the motor to the drive unit,
When the energization suppression command is input from the control unit, the driving unit stops or reduces energization to the motor according to the energization suppression command. The vehicle-mounted motor drive device according to any one of claims 1 to 21,
The on-vehicle motor drive device is a device that drives the driven part that opens and closes to either an open position or a closed position. The in-vehicle motor drive device according to claim 22,
The in-vehicle motor drive device according to claim 1, wherein the driven portion is an in-vehicle valve provided in an air intake path to the internal combustion engine or an exhaust path from the internal combustion engine in an internal combustion engine of a vehicle.

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