JP2019060333A - Valve control device, valve control method, and program - Google Patents

Abstract

An object of the present invention is to prevent an excessive pressing of a stopper of a valve body during full closing control of an exhaust valve.
An opening degree detection unit (96) for detecting the opening degree of an exhaust valve (80) and a control unit (110) for controlling the opening degree of the exhaust valve. The control unit 110 is set for the fully closed control when it is determined that the valve body contacts the housing in the fully closed control, and the contact determination unit 112 determines whether the valve body is in contact with the housing. The feedback control is performed based on the target opening change unit 118 that changes the target fully closed opening, which is the target opening, to the direction in which the exhaust valve opens and the detected opening and the changed target fully closed opening. And an FB control unit 117.
[Selected figure] Figure 4

Description

  The present invention relates to a valve control device, a valve control method, and a program capable of preventing excessive pressing of a housing by a valve body.

  In order to recover exhaust heat and use it, feedback control is performed in order to make the exhaust valve fully closed in a desired period. That is, when the valve actual opening is an opening in the opening direction from the target fully closed opening, control is performed such that the exhaust valve opening is the closing direction, while the valve actual opening is the target fully closed. When the opening degree in the closing direction is larger than the opening degree, control is performed such that the opening degree of the exhaust valve is in the opening direction.

  Also, when the valve is fully closed by the return spring, the duty value of the PWM signal given to the valve opening / closing control motor can be held at the fully closed position. There is proposed a control device which reduces the motor drive current flowing in the armature coil of the valve opening / closing motor by fixing to “(see Patent Document 1). According to this control device, the temperature of each part of the motor does not exceed the overheat limit temperature.

JP, 2015-200226, A (page 2-19, FIG. 7)

  By the way, the opening degree sensor which detects the opening degree of the valve changes the output characteristic according to the temperature change, and the exhaust valve does not close to the target opening degree according to the temperature change mode of the output characteristic. If it is closed, it may be falsely detected.

  On the other hand, if the exhaust valve is closed to the target fully closed position but erroneously detected not to the target fully closed position, control is made to close the valve even if the exhaust valve is completely closed. It will As a result, motor burnout and the like may occur. That is, in the state in which the valve body of the valve was in contact with the stopper provided in the housing, an excessive pressure in which the valve body continued to push the stopper could be generated. However, these measures have been difficult only with the temperature correction of the opening sensor.

  As in the control device described in Patent Document 1, in order to prevent burnout of the motor, constant current control is performed on the control motor so as to maintain the fully closed state at the position where the exhaust valve is fully closed. Although a configuration to perform is also proposed, constant current control only maintains the current opening of the exhaust valve. Therefore, an external force may be applied to the exhaust valve, and the exhaust valve may be opened.

  The present invention has been made to solve the conventional problems, and it is an object of the present invention to provide a valve control device, a valve control method, and a program that can prevent excessive pressing of the valve body against the stopper when fully closed. To aim.

In order to achieve the above object, the present invention is a control device of an exhaust valve in which a valve body abuts on a housing when the valve is fully closed,
An opening degree detection unit that detects the opening degree of the exhaust valve;
A control unit that controls the opening degree of the exhaust valve;
The control unit is
An abutment determination unit that determines whether the valve body abuts on the housing in the fully closed control;
A target opening change unit that changes a target fully closed opening degree, which is a target opening degree set for fully closed control, to a direction in which the exhaust valve opens by a predetermined opening degree, when it is determined that contact has occurred;
And a feedback control unit that performs feedback control based on the detected opening degree and the changed target full closing opening degree.

  Also, a temperature detection unit that detects the ambient temperature of the opening detection unit, and a correction unit that corrects the opening detected by the opening detection unit according to the ambient temperature detected by the temperature detection unit And may further be configured. As one mode, the correction unit increases the correction opening degree as the ambient temperature rises.

In addition, it has a learning unit to learn the target fully closed position after change,
The control unit causes the FB control unit to perform feedback control based on the correction opening degree and the learning value by the learning unit.

Also, the contact determination unit
(A) that the opening detected by the opening detector does not change in the closing direction;
(B) the opening degree detected by the opening degree detection unit is equal to or less than a first predetermined value;
(C) In the feedback control, when all of the fact that the operation amount of the drive source is equal to or more than the second predetermined value is satisfied, it may be determined to be in the contact state.

Also, the learning unit
When the maximum difference in the correction opening continuously acquired from the correction unit is equal to or less than the third predetermined value, and the average value of the correction opening acquired continuously is within the predetermined range,
The average of the continuously acquired corrected opening is updated and stored as the target fully closed opening and held.

  Furthermore, the opening degree detection unit may be a sensor having a temperature detection unit for detecting the valve opening degree. If the exhaust valve is provided in the exhaust system of the diesel engine to adjust the exhaust passage amount, an exhaust valve control system of the diesel engine can be realized.

Further, the method of the present invention is a control method of an exhaust valve in which the valve body abuts on the housing when the valve is fully closed,
A first step of detecting an opening degree of the exhaust valve;
And a second step of controlling the opening degree of the exhaust valve,
The second step is
In fully closed control, determining whether or not the valve body is in contact with the housing;
Changing a target fully closed opening degree, which is a target opening degree set for fully closed control, to a direction in which the exhaust valve opens by a predetermined opening degree when it is determined that the valve is in contact with the full closed control;
Feedback control based on the detected opening degree and the changed target full closing opening degree.

Further, the program of the present invention is a program for controlling an exhaust valve in which the valve body abuts on the housing when the valve is fully closed.
A first step of acquiring the opening degree of the exhaust valve;
A program for causing a computer to execute a second step of controlling an opening degree of an exhaust valve,
The second step is
A process of determining whether or not the valve body abuts the housing in the fully closed control;
A process of changing a target fully closed opening degree, which is a target opening degree set for fully closed control, to a direction in which the exhaust valve opens by a predetermined opening degree, when it is determined that contact has been made;
And a process of performing feedback control based on the detected opening degree and the changed target full closing degree.

  Furthermore, the present invention can also provide a non-transitory recording medium recording a program. Examples of non-temporary recording media for recording programs include semiconductor elements such as ROMs, optical elements such as CDs and DVDs, and magnetic elements such as magnetic disks. The type of recording medium is not limited as long as it can be executed on the computer by storing the program and reading the stored program by the reading means.

  According to the present invention, it is possible to provide a valve control device, a valve control method, and a program capable of preventing excessive pressing of the valve body against the stopper when fully closed.

FIG. 1 is a schematic explanatory view of a configuration outline of an engine 1; It is a typical block diagram of an exhaust valve system. FIG. 2 is a functional configuration diagram of a control device 100. It is a function block diagram of an exhaust valve system. FIG. 2 is a schematic configuration view of an exhaust valve 80. FIG. 10 is an explanatory diagram of a driving example of a motor 85. It is a graph which shows a temperature-opening correction coefficient. FIG. 2 is a hardware configuration diagram of a control device 100. 5 is a flowchart showing an operation example of an opening degree sensor 90. It is a flowchart which shows a normal operation example. 5 is a flowchart showing an end confirmation (contact determination) operation. It is a flow chart which shows an example of learning operation. It is a flow chart which shows an example of learning operation. It is an explanatory view of a characteristic change by temperature of opening degree sensor 90. It is a timing chart explaining operation. It is a function block diagram of the exhaust valve system of other embodiment. It is a flowchart which shows the normal operation example of other embodiment. It is explanatory drawing of the normal operation example in other embodiment. It is explanatory drawing of the specific operation example in other embodiment. It is explanatory drawing of the specific operation example in other embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. This embodiment described below is an example, and the present invention is not limited to the following embodiments. Various modifications and changes can be made to the configuration example of the present embodiment.

  In the embodiment shown below, a diesel engine 1 having four steps and four cycles and one cycle is assumed. The present invention can be applied to any number of cylinders and cylinder arrangement modes.

(Outline of Engine 1)
FIG. 1 is a schematic configuration diagram of a control system including an engine 1 and a control device 100. As shown in FIG. The engine 1 has a cylinder 2 and a piston 3 slidably fitted in the vertical direction inside the cylinder 2.

  Further, an intake pipe 50 and an exhaust pipe 60 are connected to the cylinder head at the top of the cylinder 2. An intake passage 51 for taking in fresh air into the combustion chamber 70 from the outside is formed inside the intake pipe 50. At a fresh air intake end of the intake passage 51, an air cleaner 32 for removing dust and the like of the fresh air is disposed. The timing at which fresh air is taken into the combustion chamber 70 is controlled by the valve opening / closing operation of the intake valve 12 biased in the valve closing direction by a spring (not shown).

  The injector 40 is disposed at the top of the cylinder head with its tip facing the combustion chamber. Although not shown, the fuel stored in the fuel tank is supplied to the injector 40 via the common rail, while the surplus fuel is recovered to the fuel tank via the common rail, and the injector 40 always has a predetermined pressure. Pressurized fuel is being supplied.

  On the other hand, inside the exhaust pipe 60, an exhaust passage 61 for exhausting the exhaust gas from the combustion chamber 70 is formed. At a downstream position of the exhaust passage 61, a catalyst device (not shown) or the like for purifying the exhaust gas is disposed. After purifying the exhaust gas with the catalytic converter, the noise is silenced with a silencer (not shown). The discharge timing of the exhaust gas from the combustion chamber 70 is controlled by the opening / closing operation of the exhaust valve 10 biased in the valve closing direction by a spring (not shown).

  Further, an exhaust valve 80 for adjusting the amount of exhaust flowing in the exhaust pipe 60 is provided. The mounting position of the exhaust valve 80 is not limited to this. In the vicinity of the exhaust valve 80, a motor 85 and an opening degree sensor 90 are provided. Further, a temperature sensor 95 is incorporated in the opening degree sensor 90. Although a butterfly valve is assumed as an example of the exhaust valve 80, other types of valves can also be used.

  FIG. 5 is a schematic diagram of the exhaust valve 80. As shown in FIG. FIG. 5 (a) is a schematic configuration diagram when fully closed and FIG. 5 (b) is a fully open configuration. In the exhaust valve 80, a valve shaft 520 is rotatably supported by a cylindrical housing 500, and the valve shaft 520 is provided with a disc-like valve body 530. By driving the motor 85, the valve body 530 rotates in the range from the fully open state to the fully closed state.

  In the fully open state, the normal at the center of the valve body 530 and the axis of the housing 500 are substantially perpendicular, and the exhaust valve 80 maximizes the exhaust passage amount. As shown in FIG. 5A, when the valve body 530 rotates around the valve stem 520 in the b direction from the fully closed state, the exhaust valve 80 is fully opened. Further, as shown in FIG. 5B, when the valve body 530 rotates around the valve shaft 520 in the a direction from the fully open time, the exhaust valve 80 is fully opened.

  On the other hand, in the fully closed state, the normal at the center of the valve body 530 substantially coincides with the axial center of the housing 500, and the exhaust valve 80 prevents passage of exhaust gas. At this time, the valve body 530 is in contact with the stopper 510 provided on the housing 500. This is also referred to as exhaust valve 80 or valve body 530 striking housing 500.

  Further, the valve body 530 is biased by an elastic member such as a spring so as to be in the opening direction. As an example, the opening degree region of the valve body 530 is “5 to 90 (degrees),” for example, 90 (degrees) indicates the fully open state shown in FIG. 5 (b), and 5 (degrees) indicates FIG. It is a fully closed state shown in). The opening degree sensor 90 detects the opening degree according to the opening degree of the valve body 530. The exhaust valve 90 is particularly suitable in the case of normally open, but may be normally closed.

  Further, the temperature sensor 95 is provided at an appropriate position for detecting the ambient temperature of the motor 85. The temperature sensor 95 detects the ambient temperature of the motor 85. Then, the opening degree sensor 90 detects the valve body opening degree (valve opening degree), and corrects the detected valve body opening degree with a correction coefficient corresponding to the temperature detected by the temperature sensor 95. The corrected opening is also referred to as "corrected opening".

  Further, an accelerator pedal opening degree signal, an output signal of the opening degree sensor 90, a key off signal, and the like are input to the control device 100 that controls the operation of the engine 1.

  The opening degree sensor 90 outputs a correction opening degree signal in which the opening degree of the exhaust valve 80 is corrected. A key off signal indicating that the ignition switch has been turned off is also input by the operation of the key inserted into the key device (not shown). On the other hand, the control device 100 outputs a fuel injection control signal for driving and controlling the injector 40, and a driving control signal for driving and controlling the motor 85 for controlling the opening degree of the exhaust valve 80.

  The control device 100 performs fuel injection control by the injector 40, and the ignition is natural ignition. Then, the vertical reciprocating motion of the piston 1 in the cylinder 2 is converted into rotational motion. The rotational movement is transmitted to the drive wheels via a transmission (not shown), and the vehicle (two wheels, four wheels) advances by repeating the stroke of "intake → compression → combustion → exhaust".

  FIG. 1 shows an example of the configuration of the engine 1 and the control device 100. The control device 100 refers to the intake air temperature of the engine 1, the cooling water temperature, etc. in addition to the accelerator pedal opening signal. Control can also be performed. That is, in order to improve drivability, it is also possible to calculate engine parameters such as an air-fuel ratio correction coefficient by increasing the types of sensors. Further, although an engine 1 having four cylinders and one cycle of four cylinders is assumed, any number of cylinders and cylinder arrangement may be adopted.

  In addition, DPF (Diesel Particulate Filter: diesel particulate filter) for collecting particulate matter (PM: Particulate Matter) contained in exhaust gas, DOC (Diesel for oxidizing soluble organic components in PM contained in exhaust gas) An exhaust gas purification device constituted by an oxidation catalyst (diesel oxidation catalyst) or the like may be attached.

(Features of the present invention)
FIG. 2 is a schematic configuration view schematically showing the configuration of the characterizing portion of the present invention. The engine 1 takes in fresh air through the intake pipe 50, and the exhaust gas after combustion is discharged to the outside through the exhaust pipe 60. Cooling water passes through the cooling water pipe 55, and the cooling water is circulated through a water jacket WJ provided on a cylinder head SH of the engine 1. Further, heat exchange is performed by the heat exchanger 310 between the exhaust passing through one side of the exhaust pipe 60 whose tip is bifurcated and the cooling water passing through the cooling water pipe 55 to cool the exhaust.

  An exhaust valve 80 for adjusting the flow rate of exhaust gas is provided on the other side of the bifurcated end of the exhaust pipe 60. The exhaust valve 80 is provided with a motor 85 for driving and controlling the opening degree of the valve body, and an opening degree sensor 90 for detecting the opening degree of the valve body. A temperature sensor 95 is provided in the opening degree sensor 90. The temperature sensor 95 detects the temperature around the opening degree sensor 90.

  The opening degree sensor 90 corrects the opening degree according to the temperature detected by the temperature sensor 95. The opening degree sensor 90 sends a correction opening degree signal indicating the corrected correction opening degree to the control device 100. The control device 100 changes the duty ratio (duty) of the pulse width so that the control opening of the correction opening indicated by the correction opening signal from the opening sensor 90 becomes zero and the control deviation of the target opening becomes zero. A feedback control system is configured by transmitting a Width Modulation) signal to the motor 85 as a drive control signal.

  For example, when the engine 1 is started, the exhaust valve 80 is fully closed to quickly perform the warm-up operation. On the other hand, for example, when the operating state of the engine 1 is stabilized, the exhaust valve 80 is opened to increase the displacement.

(Description of functional configuration)
FIG. 3 is a functional block diagram of the control device 100. As shown in FIG. The control device 100 includes a valve control unit 110, a storage unit 130, and a fuel injection control unit 150. The storage unit 130 includes a program 132, a map 134, a non-volatile storage area 136, and a work area 138. The work area 138 is a temporary storage area for temporarily storing parameters such as a correction coefficient in the calculation process, and the non-volatile storage area 136 is a storage area for storing a feedback correction coefficient in a non-volatile manner. In the map 132, target air-fuel ratios are set for various parameters.

  The fuel injection control unit 150 receives an accelerator pedal opening degree signal corresponding to the depression amount of the accelerator to obtain a fuel injection amount, and provides the injector 40 with a corresponding fuel injection control signal. Thus, the injector 40 injects the fuel at a fuel injection amount corresponding to the fuel injection control signal.

  The fuel injection control unit 150, for example, divides the fuel injection into halves in each of the compression stroke and the exhaust stroke until the stroke determination of the engine 1 is completed, and collectively performs the fuel injection in the exhaust stroke after the stroke determination is completed. Control is performed to provide a fuel injection control signal to the injector 40 so as to perform fuel injection control as described above.

  The valve control unit 110 controls the opening degree of the exhaust valve 80 to control the exhaust passage amount. The valve control unit 110 supplies a drive control signal for driving and controlling the motor 85 based on the correction opening degree from the opening degree sensor 90 and the target opening degree. The target opening degree may be obtained by the valve control unit 110 based on operating parameters such as the engine speed, or may be given from a host controller or the like.

(Functional configuration of valve control system)
FIG. 4 is a functional block diagram of a valve control system including the valve control unit 110. As shown in FIG. The temperature detection unit 96 outside the valve control unit 110 detects the temperature around the opening degree detection unit 91, and outputs a temperature signal indicating the detected temperature. Similarly, the opening degree detection unit 91 outside the valve control unit 110 detects the opening degree of the exhaust valve 80, and outputs an opening degree signal indicating the detected opening degree. The correction unit 92 outputs a corrected opening degree signal indicating a corrected opening degree obtained by correcting the opening degree indicated by the opening degree signal from the opening degree detecting unit 91 according to the temperature indicated by the temperature signal from the temperature detecting unit 96. Here, the temperature detection unit 96 corresponds to the temperature sensor 95, and the opening degree detection unit 91 and the correction unit 92 correspond to the opening degree sensor 90.

  The valve control unit 110 has a learning unit 114 and a control unit 116. The control unit 116 that controls the opening degree of the exhaust valve 80 includes a contact determination unit 112, an FB control unit 117, and a target opening degree changing unit 118. The contact determination unit 112 determines whether the valve body 530 contacts the stopper 510 in the fully closed control. The target opening changing unit 118 changes the target fully closed opening, which is the target opening set for the fully closed control, when it is determined that a contact is made. Then, the FB control unit 117 performs feedback control based on the corrected opening degree indicated by the corrected opening degree signal from the correction unit 92 and the changed target fully closed opening degree.

  That is, the contact determination unit 112 has a function of determining whether the valve body 530 has collided with the housing 500 in the process of driving the drive source 84 to fully close the exhaust valve 80. In addition, the learning unit 114 learns in advance the target fully closed opening degree. Here, the drive source 84 corresponds to the motor 85 as an electrical drive source.

  The target opening change unit 118 changes the target fully closed opening when it is determined that the contact is made. Here, the target fully closed opening degree is a target opening degree set for fully closed control. The FB control unit 117 performs feedback control based on the corrected opening degree from the correction unit 92 and the target fully closed opening degree changed by the target opening degree changing unit 118.

(Temperature correction of correction unit 92)
FIG. 14 is a schematic explanatory view of the characteristic change with temperature in the case where the output of the opening degree sensor 90 is expressed by a linear expression for easy understanding. Horizontal axis opening, vertical axis voltage. The "true" opening voltage characteristic shown by the straight line shown by T1 becomes T2 by temperature rise. Therefore, the voltage changes from “V1” to “V2” according to the temperature rise even if the opening degree “θ1” is the same. From “θ1 <θ2”, it can be understood that the opening degree “θ2” detected with respect to the actual opening degree “θ1” becomes large due to the temperature rise. That is, the opening degree sensor 90 has a PTC characteristic (Positive Temperature Coefficient) in which the voltage increases as the temperature rises.

  FIG. 7 shows several examples of graphs of temperature change of correction factor. FIG. 7 shows the horizontal axis “ambient temperature” and the vertical axis “correction factor”. FIG. 7 shows several examples of PTC temperature change in which the primary temperature code and the secondary temperature code are changed and combined with respect to the correction characteristics in the correction unit 92. As shown in FIG. 7, in the direction in which the ambient temperature rises, the “correction factor” increases in absolute value in the negative direction. Conversely, in the direction in which the ambient temperature decreases, the “correction factor” has a larger absolute value in the positive direction.

  Therefore, the correction unit 92 corrects the opening degree by the expression “Vout = Vin− (Vin × correction rate)”. “Vin” is a voltage corresponding to the detected opening degree, and “Vout” is a voltage corresponding to the correction opening degree. That is, correction unit 92 has the primary temperature code and the secondary temperature code so as to have PTC characteristics in the range above a predetermined temperature (25.degree. C. in the example of FIG. 7) defined as the temperature range that can be taken during operation of the vehicle. The temperature characteristic is predetermined by setting.

  However, for example, in a vehicle environment that changes from “−40 (° C.) to +120 (° C.)”, the motor impedance of the drive source 84 changes, and it is difficult to control the valve body 530 with a constant torque. Temperature correction by the correction unit 92 is not sufficient. Therefore, in the present invention, in addition to the temperature correction of the opening degree, the contact determination unit 112, the FB control unit 117, the target opening degree changing unit 118, and the like are provided.

  FIG. 6 is an explanatory diagram of drive control of the drive source 84 by the control unit 116. The control unit 116 drives and controls the drive source 84 to gradually shorten the pulse width (PW: Pulse Width) given to the drive source 84 in order to bring the exhaust valve 80 from the fully closed state to the fully open state. On the other hand, in order to drive-control the drive source 84 so that the exhaust valve 80 is fully opened or fully closed, the control unit 116 gradually increases the pulse width (PW: Pulse Width) given to the drive source 84. There is hysteresis because of the friction of the valve.

  As an example, the drive source 84 (motor 85) is driven by the electric current from "-1.6 (A)" to "-0.1 (A)" from fully closed to fully open.

(Hardware configuration diagram)
FIG. 8 is a hardware block diagram of the control device 100. As shown in FIG. The control device 100 includes an A / D converter 250, a CPU 200, a ROM 210, a RAM 220, and a flash memory 230. The A / D converter 250 sends, to the CPU 200, an accelerator pedal opening signal corresponding to the depression amount of the accelerator and a signal obtained by analog-to-digital conversion of the correction opening signal from the opening sensor 90.

  On the other hand, the CPU 200 sends a fuel injection control signal to the injector 40. Further, a motor drive circuit 240 for driving and controlling the motor 85 is provided. The CPU 200 outputs a command signal to the motor drive circuit 240 so that the deviation between the target opening degree of the valve body 530 and the correction opening degree obtained from the result of calculation based on the detection signals of the respective sensors becomes zero. A PWM signal for driving and controlling the motor 85 is output from the motor drive circuit 240 to the motor 85 based on a command signal input from the CPU 200.

  The CPU 200 reads the program 132 recorded in the ROM 210 and executes the program 132 while using the work area 138 formed in the RAM 220. In the execution process, the calculated correction coefficient and the like are updated and stored in the nonvolatile storage area 136 of the flash memory 230. Further, the map 134 stored in the flash memory 230 is used to set the target air-fuel ratio for the operating state and to obtain the target air-fuel ratio based on the current operating state.

  The valve control unit 110 and the fuel injection control unit 150 shown in FIG. 3 can be realized by the CPU 200 executing the program 132 stored in the recording medium such as the ROM 210 or the like. In addition, the ROM 210, the RAM 220, and the flash memory 230 implement the storage unit 130.

  The control unit 116, the learning unit 114, and the like constituting the valve control unit 110 shown in FIG. 4 can be realized by the CPU 200 executing the program 132. Further, the opening degree detection unit 91 and the correction unit 92 that constitute the opening degree sensor 90 can be realized by executing a program by a dedicated IC or CPU. In this CPU, the CPU 200 of the control device 100 may correct the opening degree, or a separate CPU may be provided with a dedicated CPU.

(Operation example)
(Operation of opening sensor 90)
FIG. 9 is a flowchart illustrating an operation example of the opening degree sensor 90. First, in step S900, the temperature detection unit 96 detects the ambient temperature of the opening degree sensor 90, and sends the detection result to the correction unit 92. Further, the opening degree detection unit 91 detects the opening degree of the exhaust valve 80 and sends the detection result to the correction unit 92. Next, in step S910, temperature correction is performed. The correction unit 92 corrects the opening signal input from the opening detection unit 91 with a correction coefficient corresponding to the temperature signal input from the temperature detection unit 96, and calculates and outputs a correction opening signal.

  Specifically, the correction unit 92 refers to a temperature table as shown in FIG. 7 to obtain a correction factor for the ambient temperature. The correction unit 92 obtains a corrected opening degree signal (Vout) from the opening degree signal (Vin) input from the opening degree detecting unit 91 according to an expression “Vout = Vin− (Vin × correction rate)”. Here, the correction of the opening degree is not limited to the example realized using the temperature table. For example, it may be realized by a circuit that outputs the corrected opening degree signal (Vout) according to the input of the opening degree signal (Vin). This circuit is formed of, for example, a circuit in which a plurality of diodes and a plurality of resistors are connected in a network.

  Next, in step S920, the correction unit 92 sends the calculated correction opening signal (Vout) to the control unit 116. Thus, the opening degree detection unit 91 detects the opening degree of the exhaust valve 80, and the correction unit 92 corrects the opening degree detected by the opening degree detection unit 91 according to the temperature. Is generated and output to the control unit 116, the valve control unit 110 can obtain the corrected opening degree.

(Normal operation)
FIG. 10 is a flowchart for explaining the normal operation. When it is determined in step S100 that the exhaust valve 80 should be fully closed, or when instructed by another control unit or the like, the control unit 116 operates the drive source 84 to fully close the valve body 530. Control. The FB control unit 117 included in the control unit 116 sets the correction opening calculated by the correction unit 92 as the actual opening, the target opening as the target fully closed opening, and the drive source 84 so that the control deviation between the two becomes zero. Feedback control (also referred to as “FB control”) is performed by giving a PWM signal (operation amount) to The target fully closed opening degree has an initial value set in advance in the non-volatile storage area 136, and is updated by a learning operation described later. If the deviation between the correction opening degree and the target opening degree does not decrease, the FB control unit 117 performs control so that the control deviation between the two becomes zero by gradually increasing the duty.

  In step S105, in the FB control in which the valve is fully closed, the contact determination unit 112 determines whether or not the opening degree of the exhaust valve 80 becomes the fully closed position, and the valve body 530 abuts against the stopper 510 of the housing 500. Do. If the contact determination unit 112 determines that the valve body 530 does not abut the stopper 510 of the housing 500 (No), the process proceeds to step S115. On the other hand, when the contact determination unit 112 determines that the valve body 530 has hit the stopper 510 of the housing 500 (Yes), the process proceeds to step S110.

  In step S110, the target opening change unit 117 included in the control unit 116 changes the target fully closed opening degree to a predetermined opening degree, in the opening direction, and proceeds to step S115. In step S115, the FB control unit 117 determines whether or not the FB control has ended. If the FB control has not ended (No), the process returns to step S105 to continue the FB control.

  On the other hand, when the FB control is ended (Yes), the processing is ended. Here, the predetermined opening degree is, for example, four resolutions (for example, about 0.1 °) in which the minimum unit capable of driving and controlling the motor 85 is one resolution. As an example, if the motor 85 is controlled by the operation amount of 12 bits and the valve opening degree is controlled in the range of “5 to 90 °”, it is as follows.

  Of the operating voltage total range “0 (mV) to 5000 (mV)”, the entire range is 12 bits, using the range “full closed 5 ° to full open 90 °: 500 (mV) to 4500 (mV)” When capturing at (= 4096), the range occupied by “500 (mV) to 4500 (mV)” in 12 bits is “(4000/5000) × 4096 ≒ 3277 (LSB)”, so “1 LSB = 85/3277 = 0.0259 °. In this example, the exhaust valve 90 can be controlled to open and close in units of "0.0259".

  When the target opening changing unit 117 changes the exhaust valve 80 in the opening direction by a predetermined opening, basically, the predetermined opening is a fixed amount, but the above-described predetermined opening is changed according to the temperature. It can also be done. At this time, the above-mentioned predetermined opening degree is changed with a preset set limit value as a limit. For example, it is also possible to adjust the opening degree by defining the predetermined opening degree as a linear function of temperature. According to this, in addition to the correction of the opening degree according to the temperature, the responsiveness and the accuracy of the fully closed control of the exhaust valve 80 are improved. Further, instead of the linear function, it is also possible to define the above-mentioned predetermined opening degree by an n-order function of temperature (n is an integer of 2 or more) or the like.

  As described above, the contact determination unit 112 determines whether the valve body 530 contacts the stopper 510 in the process of controlling the drive source 84 so that the opening degree of the exhaust valve 80 becomes the target full closing degree. The FB control unit 117 performs the FB control based on the corrected opening degree and the target fully closed opening degree after the change by the target opening degree changing unit 118. As a result, when the target fully closed opening degree is changed to the opening direction by the predetermined opening degree at the fully closing operation, the excessive pressing of the valve body 530 against the stopper 510 is eliminated, and the fuel loss and the like of the motor 85 is eliminated.

(Abutment (end) determination operation)
FIG. 11 is a flowchart showing an operation example of the “jump determination (contact determination)” of step S105. The “contact determination” in step S122 is the same operation. First, in step S112, the contact determination unit 112 determines whether the correction opening degree from the correction unit 92 has changed in the closing direction. If it is determined that there is no change (Yes), the process proceeds to step S114. Otherwise (No), the present routine is ended.

  Next, in step S114, it is determined whether the correction opening degree is equal to or less than a predetermined opening degree. If it is determined that the opening degree is less than or equal to the predetermined opening degree (Yes), the process proceeds to step S116, while if otherwise (No), the present routine ends. Next, it is determined whether the duty ratio of the PWM signal at the time of FB control is equal to or greater than a predetermined duty ratio. If it is determined that the duty ratio of the PWM signal is equal to or higher than the predetermined duty ratio of the PWM control (Yes), the process proceeds to step S118. Otherwise (No), the present routine is ended.

  In step S <b> 118, the contact determination unit 112 determines that the valve body 530 is in the contact state in which the valve body 530 contacts the stopper 510. That is, when all the steps S112, S114, and S116 are satisfied, the contact determination unit 112 recognizes that it is in the contact state.

  As described above, the contact determination unit 112 (a) does not change the opening detected by the opening detection unit 91 in the closing direction, (b) the correction opening detected by the opening detection unit 91 is predetermined It is determined that the valve body 510 is in contact with the stopper 510 when all the conditions that the operating amount of the drive source 84 is equal to or more than a predetermined value are satisfied in (c) FB control. For example, a new sensor or the like for determining the contact is not necessary, and it can be determined whether the contact is made only by a simple algorim.

(Learning behavior)
FIG. 12 is a flowchart illustrating the learning operation. When the control unit 116 receives the key-off signal, the control unit 116 activates the learning unit 114. In step S120, the learning unit 114 performs full closing control of the exhaust valve 80. Next, in step S122, the learning unit 114 controls the contact determination unit 112 to determine whether the valve body 530 of the exhaust valve 80 contacts the stopper 510 of the housing 500.

  If it is determined that the contact determination unit 112 is in the contact state (Yes), the process proceeds to step S124. Otherwise, the present routine ends. Then, in step S124, learning is performed. That is, in step S122, when it is determined to be in the contact state, the correction opening signal output from the correction unit 92 is received, and the opening voltage corresponding to the correction opening signal is the target at the start of full closing control. It is updated and stored as the fully closed position and held in the non-volatile storage area 136.

  As described above, when the learning unit 114 is configured to learn the target fully closed position, it is possible to obtain an optimal target fully closed position. The learning by the learning unit 114 is preferably performed after the end of driving such as when the key is off so as not to burden the user. In addition, it is preferable to refer to the learning value by the learning unit 114, for example, when it is assumed that the contamination becomes severe due to the wrinkles of the exhaust valve 80, such as when the DPF (Diesel Particulate Filter) is regenerated.

  When the learning unit 114 is activated, the valve control unit 110 refers to the learning value obtained by the learning unit 114 as the target fully closed position. When the fully closing operation of the exhaust valve 80 is instructed, the FB control unit 117 performs the FB control based on the correction opening degree and the learning value by the learning unit 114. Therefore, the responsiveness during the fully closing control is good. Become. That is, since the FB control based on the learning value and the correction opening degree acquired from the opening degree sensor 90 is performed by the FB control unit 117, there is an advantage such as improvement of responsiveness in full closing control.

  In addition, when the DPF is reconstructed, the control unit 116 recognizes this fact, reads the learning value stored in the non-volatile storage area 136, and uses it to achieve the target full closure used during normal operation. Used as an opening. Note that the timing of referring to the learning value of the learning unit 114 is not limited to the time of DPF reconstruction.

(Learning process)
FIG. 13 is a flow chart for explaining the details of the “learning operation” in step S124 of FIG. In step S130, the learning unit 114 obtains the correction opening degree a plurality of times consecutively from the correction unit 92. In step S132, the learning unit 114 determines whether the difference “max−min” between the maximum value and the minimum value is equal to or less than a predetermined value “Δm”. If it is determined that the difference "max-min" between the maximum value and the minimum value is less than or equal to the predetermined value ".DELTA.m" (Yes), the process proceeds to step S134, while otherwise (No) , End this routine.

  In step S134, the learning unit 114 determines whether the average value of the continuously acquired corrected opening degree is within a predetermined range centered on the predetermined fully closed opening degree. For example, when the average value is within 500 (mV) ± 200 (mV), the learning unit 114 determines that the value is within the predetermined range. If it is determined that the average value is within the predetermined range (Yes), the process proceeds to step S136. If it is determined that the average value is other than this (No), the present routine is ended. In step S136, the learning unit 114 updates and stores the average value as the target fully closed position and holds the average value in the non-volatile storage area 136.

  As described above, the learning unit 114 has a continuous acquisition function of continuously acquiring a plurality of correction opening degrees from the correction unit 92, and the maximum difference in the continuously acquired correction opening degrees is equal to or less than a predetermined value, and continuously. When the average value of the acquired corrected opening degree falls within the predetermined range, the average of the continuously acquired corrected opening degree is updated and stored as the target fully closed opening degree, so the desired fully closed opening degree is learned only with a simple algorithm. can do.

  As described above, the correction unit 92 corrects the opening detected by the opening detection unit 96 (the opening sensor 90) according to the temperature detected by the temperature detection unit 96 (the temperature sensor 95). Calculate the corrected opening degree. The control unit 110 drives and controls the drive source 84 (motor 85) so that the exhaust valve 80 is fully closed, based on the correction opening degree and the target fully closed opening degree.

  Then, the abutment determination unit 112 determines whether the valve body 530 abuts against the stopper 510 in the fully closed control process of the exhaust valve 80, and when it is determined that the valve body 530 abuts, the target opening degree change The unit 118 changes the target fully closed opening degree, so the FB control unit 117 performs the FB control based on the correction opening degree and the changed target fully closed opening degree.

  Therefore, in conjunction with the correction of the temperature characteristic, when the valve body 530 abuts on the stopper 510, the target fully closed opening degree is changed, and the changed target fully closed opening degree, the actual opening of the valve body 530 Based on the correction opening degree, which is a degree, the FB control for fully closing the exhaust valve 80 is performed, so that the excessive pressing of the valve body 530 against the stopper 510 is eliminated. As a result, it is possible to prevent the fuel loss and the like of the motor 85 from occurring.

  Further, since the opening degree detection unit 96 (the opening degree sensor 90) includes the correction unit 92, the control load on the control device 100 side such as the valve control 110 can be reduced. The correction unit 92 may be provided on the control device 100 side, and the control device 100 side may correct the opening degree detected by the opening degree detection unit 96.

(Characteristic operation example)
FIG. 15 is an explanatory view of a characteristic operation / effect example of the present invention. In the figure, TS1, TS2, and TS3 indicate that the valve body 530 abuts on a stopper 510 provided on the housing 500. The vertical axis represents the temperature from the top, the detected opening signal output from the opening sensor 90, the target opening of the FB control, and the actual opening. The horizontal axis shows time.

  When the temperature rises, the detection opening can not be corrected only by the temperature correction, and the detection opening tends to rise. Therefore, the actual opening degree of the valve body 530 is controlled so that the detected opening degree maintains the target opening degree. However, when the valve body 530 abuts on the stopper 510, the actual opening can not be controlled according to the change in the detected opening, and the detected opening increases. Therefore, it is determined whether or not the valve body 530 abuts on the stopper 510, and if it is determined that the valve body 530 abuts, the target opening degree is changed in the opening direction by a predetermined angle. “TS1” is the first abutment of the valve body 530 against the stopper 510. From “TS1”, it can be seen that the “target opening degree (target full closing opening degree)” is changed by a predetermined opening degree in the opening direction. The feedback control is performed so that the difference between the changed “target opening” and the “detected opening” becomes zero.

  As time passes, a second contact "TS2" to the stopper 510 of the valve body 530 occurs, but the "temperature" is further increased up to that point. Since it can not be corrected only by the temperature correction of the detection opening degree, the "target opening degree" is further changed to a predetermined angle and opening direction. It can be seen that the "target opening" has been changed by a predetermined opening in the opening direction. Feedback control is performed so that the difference between the changed “target opening” and the “detected opening” becomes zero.

  Furthermore, although time passes and the 3rd contact "TS3" to stopper 510 of valve object 530 has arisen, "temperature" has risen further to that time. Since the correction of the detected opening can not be completed by the temperature correction alone, the "target opening" is further changed by a predetermined angle in the opening direction. It can be seen that the "target opening" has been changed by a predetermined opening in the opening direction. Feedback control is performed so that the difference between the changed “target opening” and the “detected opening” becomes zero.

  Thus, when the valve body 530 abuts against the stopper 510, the "target opening" is changed in the opening direction, and at this time, if the temperature rise continues, the "target opening" has a predetermined opening in the opening direction, The feedback control is performed so that the control deviation between the changed "target opening" and the "detected opening" becomes zero. In the fully closed control operation, it is determined whether or not the valve body 530 abuts against the stopper 510, and when it is determined that the valve body 530 abuts, the target fully closed opening degree is changed to the opening direction. Excessive pressure on the stopper 510 is eliminated, and fuel loss and the like of the motor are prevented. In addition, since the opening degree of the valve body 530 is maintained in the vicinity of the fully closed opening degree, it is possible to realize a valve with a low leak amount while being a butterfly valve.

(Other embodiments)
The present embodiment is characterized in that a duty change unit 119 is provided instead of the target opening change unit 118 shown in FIG. 4. When it is determined that the valve body 530 abuts on the housing 500, the duty changing portion 119 closes the valve body 530 by the motor 85 by reducing the duty of the pulse of the PWM signal supplied to the motor 85 to a predetermined value. It has a function to weaken the power. In the present specification, “duty” and “duty ratio” are synonymous, and theoretically, “duty (duty ratio) = pulse width / pulse period”.

  FIG. 16 is a functional configuration diagram of a control system according to the present embodiment. The temperature detection unit 96 provided outside the valve control unit 110 detects the temperature around the opening degree detection unit 91, and outputs a temperature signal indicating the detected temperature. Further, the opening degree detection unit 91 provided outside the valve control unit 110 detects the opening degree of the exhaust valve 80 and outputs an opening degree signal indicating the detected opening degree. The correction unit 92 outputs a corrected opening signal indicating a corrected opening degree obtained by correcting the opening degree indicated by the opening degree signal output from the opening degree detecting unit 91 according to the temperature indicated by the temperature signal from the temperature detecting unit 96. Do.

  The valve control unit 110 has a learning unit 114 and a control unit 116. The control unit 116 that controls the opening degree of the exhaust valve 80 includes a contact determination unit 112, an FB control unit 117, and a Duty change unit 119. The contact determination unit 112 determines whether the valve body 530 contacts the stopper 500 in the fully closed control. When it is determined that the valve body 530 abuts on the housing 500, the duty changing unit 119 reduces the duty of the PWM control pulse supplied to the motor 85 to a predetermined value, and forces the motor 85 to close the valve body 530. Have the ability to

  Then, the learning unit 114 learns in advance the target fully closed opening degree, and the FB control unit 117 sets the corrected open degree indicated by the corrected opening degree signal from the correcting unit 92, and the target fully closed opening degree previously learned. Perform feedback control based on That is, when it is determined that the valve body 530 is in contact with the housing 500, the duty changing unit 119 reduces the duty of the PWM signal supplied to the motor 85 to weaken the torque with which the valve body 530 presses the housing 500. Thus, the motor 85 is prevented from being burnt and the like.

(Operation example)
The learning operation performed by the learning unit 114 is the same as the operation example described above with reference to FIGS. 12 and 13, and the contact determination operation is the same as the operation example described with reference to FIG. Therefore, the description of the second time is omitted.

  FIG. 17 is a flowchart for explaining the normal operation in the present embodiment. When it is determined in step S100 that the exhaust valve 80 should be fully closed, or when instructed by another control unit or the like, the control unit 116 operates the drive source 84 to fully close the valve body 530. Control. The FB control unit 117 performs feedback control (FB control) so that the control deviation between the two becomes zero, based on the correction opening degree calculated by the correction unit 92 and the target fully closed opening degree. In the FB control, the target fully closed opening degree is learned in advance by the learning unit 114. If the deviation between the correction opening degree and the target opening degree does not decrease, the FB control unit 117 performs control so that the control deviation between the two becomes zero by gradually increasing the duty.

  Next, in the FB control process of fully closed valve, the contact determination unit 112 determines whether or not the opening degree of the exhaust valve 80 becomes the fully closed degree and the valve body 530 butts against the stopper 510 of the housing 500. (Step S105). If the contact determination unit 112 determines that the valve body 530 does not contact the stopper 510 (No), the process proceeds to step S115. On the other hand, when the contact determination unit 112 determines that the valve body 530 has hit the stopper 510 of the housing 500 (Yes), the process proceeds to step S111.

  In step S111, when it is determined that the valve body 530 is in contact with the housing 500, the duty changing unit 119 reduces the duty of the pulse of the PWM signal supplied to the motor 85 to a predetermined value, Weaken the force to close 530 and finish FB control.

  In step S115, the FB control unit 117 determines whether or not the FB control has ended. If the FB control has not ended (No), the process returns to the step S105 and continues the FB control while the FB control Is terminated (Yes), the process ends.

  In this manner, when it is determined that the valve body 530 abuts on the housing 500, the duty changing portion 119 reduces the duty to a predetermined value, so the pressing force of the valve body 530 against the housing 500 becomes excessive. Is blocked. As a result, burnout of the motor 85 and mechanical damage at the contact point between the valve body 530 and the housing 500 can be eliminated.

(Specific operation example 1)
FIG. 18 is a simulation example of a specific operation. The upper part of FIG. 18 shows an example of time change of the valve opening degree, and the horizontal axis is “time”, and the vertical axis is “valve opening degree”. The lower part of FIG. 18 shows an example of time change of the duty of the PWM pulse, the horizontal axis is “time” and the vertical axis is “valve opening degree”.

  As shown in the upper part of FIG. 18, the valve opening degree is changed from the fully open valve state (3500 (LSB)) to the fully closed valve state (500 (LSB)). Immediately after starting the fully closing operation from the fully open state of the valve body 530, the valve body closing operation is performed at a quick speed, but the speed is reduced immediately before the fully closed state. Thus, the impact of the valve body 530 on the housing 500 is suppressed. Therefore, the waveform of the temporal change of the valve opening is curved near the fully closed state. As an example, the valve body 530 is closed at a valve closing speed of 60 (deg / sec) or less at first from the fully open state, and the valve closing speed is decreased near the fully closed state to 40 or less. Close the valve body 530 at the speed.

  At this time, the FB control unit 117 performs feedback control (FB control) so that the control deviation between the two becomes zero, based on the correction opening degree calculated by the correction unit 92 and the target fully closed opening degree. If the deviation between the correction opening degree and the target opening degree does not decrease, the FB control unit 117 performs control so that the control deviation between the two becomes zero by gradually increasing the duty. Further, at this time, the FB control unit 117 performs control so that the duty does not exceed the predetermined allowable upper limit 50 (%). Therefore, when the valve body 530 abuts against the stopper 510 before the control deviation of the correction opening degree and the target full closing opening degree becomes zero due to a specific change of the opening degree sensor 90 due to temperature, FB The control unit 117 keeps increasing the duty gradually, but maintains the value after increasing it to the allowable upper limit 50 (%).

  When it is determined by the contact determination unit 112 that the valve body 530 contacts the stopper 510 of the housing 500, the control system is shifted from the FB control in the closed loop to the open loop control.

  After the duty changing unit 119 maintains the duty at the allowable upper limit 50 (%) for a predetermined period, the learning operation shown in FIG. 13 by the learning unit 114 is performed, and the target fully closed opening degree is updated and stored. Thereafter, the duty changing unit 119 reduces the duty to approximately 20 (%) (see symbol A). The learning operation of the target fully closed position by the learning unit 114 may not necessarily be performed.

  FIG. 19 is an explanatory view schematically showing the time change of the duty shown in the lower part of FIG. 18 in an enlarged manner. The control system is a closed loop until it is determined that a contact is made, and the FB control is performed by the FB control 117. Thereafter, the control system becomes an open loop, and the duty changing unit 119 has a duty of 50 (%) After maintaining the allowable upper limit value for the predetermined time, as shown by a symbol A, a change operation is performed to reduce the duty to about 20 (%). Thereby, the torque of the motor 85 is reduced to prevent excessive pressing of the valve body 530 on the housing 500.

(Specific operation example 2)
FIG. 20 is a simulation example of another specific operation. The upper part of FIG. 20 shows an example of time change of the valve opening degree, the horizontal axis is "time" and the vertical axis is "valve opening degree". The lower part of FIG. 20 shows an example of time change of the duty of the PWM pulse, the horizontal axis is "time" and the vertical axis is "valve opening degree".

  Also in the operation example of FIG. 20, when the valve opening is changed from the valve fully closed state (3500 (LSB)) to the valve fully closed state (500 (LSB)), as in the operation example shown in FIG. When the contact determination unit 112 determines that the valve body 530 is in contact with the housing 500, the duty change unit 119 performs a change operation to reduce the duty to about 20 (%) as indicated by a symbol A. .

  Then, even if the exhaust valve 80 is opened due to the external force being applied to the exhaust valve 80 due to the disturbance (refer to the symbol B), the duty changing section 119 has a duty of 50 (%) by the open loop. It is increased to the allowable upper limit value and reduced to about 20 (%) after maintaining for a predetermined time. When the target opening degree is changed to a predetermined opening degree other than full closing (for example, in the case of opening the valve), the control shifts to FB control again.

  In order to reduce the heat generation of the motor 85 as much as possible, even if the exhaust valve 80 is opened due to disturbance, the exhaust valve 80 is not closed again until the predetermined period (5 (sec) in the example) elapses. ing. That is, even when the correction opening degree changes in the opening direction due to the disturbance, the duty changing portion 119 has a predetermined period if the predetermined period has not elapsed since the duty was reduced to about 20 (%). After the elapse of time, the duty is increased to the upper limit of 50 (%). The above-described changed duty 20 (%) and allowable upper limit value 50 (%) of duty are examples of values determined by the impedance characteristic of the motor 85 and the like.

  According to the valve control system of the other embodiment described above, the opening degree detection unit 91 that detects the opening degree of the exhaust valve, and the control unit 116 that controls the motor 85 that adjusts the exhaust valve opening degree by PWM. Have.

  Then, in the fully closed control, the control unit 116 determines whether the valve body 530 contacts the housing 500 or not, and the duty in the motor PWM control when it is determined that the valve body 530 contacts. It includes a Duty changing unit 119 to be changed, and an FB control unit 117 that performs feedback control of motor drive based on the detected opening degree and the target fully closed opening degree learned in advance.

  As a result, when the valve is fully closed, excessive pressing of the valve body 530 onto the housing 500 is suppressed, and the occurrence of mechanical damage or the like at the contact point between the valve body 530 and the housing 500 is prevented. It will be possible to

  The parameters such as the duty change amount and the allowable upper limit value of the duty can be set to an appropriate value in consideration of the characteristics of the motor 85, control parameters such as a delay element of the control system, and the like.

  Although described above, the present invention is not limited to the above embodiment, and various modifications and changes are possible. In the above embodiment, although a system that performs exhaust heat recovery to achieve early warm-up of the engine has been described as an example, it is not limited to this as long as it is a system where exhaust valve control is performed. For example, the above-described exhaust valve control can be applied to a system that performs a Rankine cycle, an EGR shutter, a sound tuning, and a cylinder deactivation.

  Further, in step S110, the learning operation shown in FIG. 13 by the learning unit 114 is executed to update and store the target fully closed opening degree, and then the updated target fully closed opening degree is set to the predetermined opening degree and opening direction. It may be changed to

As described above, the present invention can be applied to an engine control device or the like that performs exhaust control.

1 engine 80 exhaust valve 85 motor 90 opening sensor 91 opening detection unit 92 correction unit 95 temperature sensor 96 temperature detection unit 100 control device 110 valve control unit 112 contact determination unit 114 learning unit 117 FB control unit 118 target opening change Section 119 Duty changing section 120 Feedback control section 132 Program 150 Fuel injection control section 160 Ignition control section 500 Housing 510 Stopper 530 Valve body

Claims (10)

A control device of an exhaust valve in which a valve body is in contact with a housing when the valve is fully closed,
An opening detection unit that detects the opening of the exhaust valve;
A control unit that controls the opening degree of the exhaust valve;
The control unit
An abutment determination unit that determines whether or not the valve body abuts on the housing in the fully closed control;
A target opening change unit that changes the target fully closed opening degree, which is the target opening degree set for the fully closed control, to a direction in which the exhaust valve opens by a predetermined opening degree when it is determined that contact has been made When,
And a feedback control unit configured to perform feedback control on the basis of the detected opening degree and the changed target fully closed opening degree. An apparatus according to claim 1, wherein
A temperature detection unit that detects an ambient temperature of the opening degree detection unit;
A valve control device, further comprising: a correction unit configured to correct the opening degree detected by the opening degree detection unit according to the ambient temperature detected by the temperature detection unit. An apparatus according to claim 1 or 2, wherein
The correction unit is
A valve control device characterized in that the correction opening degree is increased as the ambient temperature rises. An apparatus according to any one of claims 1, 2 and 3, wherein
A learning unit for learning the target fully closed position after the change;
The control unit
A valve control device characterized in that the feedback control is performed based on the detected opening degree and the learning value by the learning unit. A device according to any one of claims 1, 2, 3 and 4 wherein
The contact determination unit is
(A) the opening detected by the opening detector does not change in the closing direction;
(B) the opening degree detected by the opening degree detection unit is equal to or less than a first predetermined value;
(C) In the feedback control, the operation amount of the drive source is equal to or greater than a second predetermined value,
A valve control unit that determines that the contact state is in the case where all of the conditions are satisfied. The apparatus according to claim 4, wherein
The learning unit is
When the maximum difference in the corrected opening continuously acquired from the correction unit is equal to or less than a third predetermined value, and the average value of the continuously detected opening is within a predetermined range,
A valve control device characterized in that an average value of the continuously detected opening degree is updated and stored as a target fully closed opening degree. A device according to any one of claims 1, 2, 3, 4, 5 and 6, wherein
The opening degree detection unit
A valve control device comprising the temperature detection unit and the correction unit, which is a sensor for detecting a valve opening degree. A device according to any one of claims 1, 2, 3, 4, 5, 6 and 7, wherein
The exhaust valve is
A valve control device comprising a valve provided in an exhaust system of a diesel engine to adjust an exhaust gas passage amount. A control method of an exhaust valve in which a valve body abuts on a housing when the valve is fully closed.
A first step of detecting an opening degree of the exhaust valve;
And d) controlling the opening degree of the exhaust valve.
The second step is
In fully closed control, determining whether or not the valve body is in contact with the housing;
Changing a target fully closed opening degree, which is a target opening degree set for the fully closed control, to a direction in which the exhaust valve opens by a predetermined opening degree when it is determined that the valve is in contact;
Performing feedback control on the basis of the detected opening degree and the changed target full closing opening degree. A program for controlling an exhaust valve in which a valve body abuts on a housing when the valve is fully closed,
A first step of acquiring the opening degree of the exhaust valve;
And a second step of controlling the opening degree of the exhaust valve.
The second step is
A process of determining whether or not the valve body is in contact with the housing in the fully closed control;
A process of changing a target fully closed opening degree, which is a target opening degree set for the fully closed control, to a direction in which the exhaust valve opens by a predetermined opening degree, when it is determined that contact has occurred;
And a process of performing feedback control based on the detected opening degree and the changed target full closing degree.

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