JPH11223134A - Throttle control device for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve follow stability of the opening of a throttle valve, in an electronic throttle system using a torque motor. SOLUTION: In an electronic throttle system using torque motor 19, motor torque characteristics are nonlinear and are determined by a plurality of parameters (an actual throttle opening, and a motor current). Further, when a reduction gear train is not arranged, throttle opening precision is reduced, and in conventional PID(proportional.integration.differentiation) control, absorption of the non-linear characteristics of an electronic throttle is difficult to make. Therefore, a control amount by which an actual throttle opening TA opening is caused to coincide with a target throttle is calculated according to motor current necessary to the generation of demand torque in consideration of inertia of the motor 19 in a throttle control system. This constitution absorbs the non-linear torque characteristics of the torque motor 19 and performs accurate throttle control.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a throttle control device for an internal combustion engine that controls a degree of opening of a throttle valve by driving a torque motor according to an accelerator operation amount or the like.

[0002]

2. Description of the Related Art Conventionally, an internal combustion engine called an "electronic throttle system" for controlling a real throttle opening which is an actual throttle valve opening by driving a DC (direct current) motor as an actuator in accordance with an accelerator operation amount or the like. Is known. In such a throttle control device, for example, a motor current is supplied to a DC motor in accordance with a signal from an accelerator opening sensor that detects an accelerator opening corresponding to the amount of depression of an accelerator pedal.
When the C motor is driven, the throttle valve is opened and closed to control the amount of air supplied to the internal combustion engine. At this time, proportional / integral / differential control (Proportional Integral Differential Control; hereinafter) is performed on the DC motor so that the deviation between the signal from the throttle opening sensor that detects the actual throttle opening and the signal from the accelerator opening sensor is eliminated. , Simply referred to as “PID control”).

[0003]

It is known that the torque characteristics of a DC (direct current) motor can be approximated by T = KT × i. Here, T is a motor torque, KT is a torque constant, and i is a motor current. That is,
This shows that the motor torque T can be obtained almost linearly according to the motor current i.

On the other hand, in an electronic throttle system, the drive mechanism around the throttle valve is simplified, the number of parts is reduced, and the cost is reduced.
It is conceivable to use a torque motor instead of a DC motor as the actuator. The torque characteristic of this torque motor is such that the motor torque T [N · m] is a function T = f (θ, θ) of the actual throttle opening θ [°] and the motor current i [A].
i), that is, a two-dimensional map as shown in FIG. FIG. 13 shows only the relationship between the actual throttle opening θ and the motor torque T when the motor current i is on the positive side. Further, in a configuration in which the reduction gear train is not provided in a stage preceding the rotation axis of the throttle valve, the accuracy of the throttle opening is reduced.

Therefore, in an electronic throttle system using a torque motor, it is impossible to perform accurate throttle control by absorbing nonlinear torque characteristics and the like of the torque motor by feedback control of PID control.

Accordingly, the present invention has been made to solve such a problem, and it is possible to improve the follow-up stability of the opening degree of a throttle valve in an electronic throttle system using a torque motor, and to improve the drive mechanism around the throttle valve. It is an object to provide a throttle control device for an internal combustion engine that can be simplified.

[0007]

According to the throttle control device for an internal combustion engine of the first aspect, the control amount for making the actual throttle opening controlled by the throttle control means coincide with the target throttle opening is adjusted to the target throttle opening. The control amount is calculated by the control amount calculating means in accordance with the motor current calculated from the required torque of the torque motor and the actual throttle opening calculated by the torque calculating means in accordance with the deviation between the throttle opening and the actual throttle opening. That is, in the electronic throttle system using the torque motor, the number of parts is small, the mechanism is simplified, and the friction can be reduced. However, the actual throttle opening relative to the target throttle opening tends to overshoot due to the influence of inertia and the like. Tend to be. For this reason, the control amount for making the actual throttle opening coincide with the target throttle opening is calculated according to the motor current required to generate the required torque in consideration of the inertia of the torque motor in the throttle control system. As a result, the non-linear torque characteristics of the torque motor are absorbed, so that accurate throttle control becomes possible, and the follow-up stability of the actual throttle opening with respect to the target throttle opening can be improved.

In the throttle control apparatus for an internal combustion engine according to the second aspect, feedback is performed so that the actual throttle speed matches the target throttle speed calculated by the torque calculating means in accordance with the deviation between the target throttle opening and the actual throttle opening. By performing the control, the influence of the inertia and the like of the throttle control system is removed, and the required torque of the torque motor can be accurately calculated.

In the throttle control device for an internal combustion engine according to the third aspect, the target throttle opening has a non-linear characteristic such that the rate of increase of the target throttle speed changes depending on the magnitude of the deviation between the target throttle opening and the actual throttle opening. Since the change in the opening is controlled to be slower as the actual throttle opening approaches, the following stability of the actual throttle opening with respect to the target throttle opening can be improved.

According to a fourth aspect of the present invention, the control amount calculating means calculates a control amount reflecting at least one of an inertia force, a friction torque, a spring torque and a back electromotive force in the throttle control system. By driving the torque motor based on the control amount, the stability of following the actual throttle opening with respect to the target throttle opening can be improved.

In the throttle control device for an internal combustion engine according to the present invention, the motor current has different characteristics on the positive side (forward rotation) and the negative side (reverse rotation), so that the motor current has a predetermined value with respect to the same actual throttle opening. Since a motor current having a magnitude corresponding to the required torque can be obtained, it is possible to cope with a unique shape such as a structure in the rotational direction of the torque motor that is not symmetrical, and to stably follow the actual throttle opening with respect to the target throttle opening. Performance can be improved.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below based on examples.

FIG. 1 is a schematic configuration diagram showing an internal combustion engine to which a throttle control device for an internal combustion engine according to an embodiment of the present invention is applied, and peripheral devices thereof.

In FIG. 1, an internal combustion engine 1 is configured as a V-type six-cylinder four-cycle engine. Internal combustion engine 1
An air cleaner 3 is provided on the upstream side of the intake passage 2 of
An air flow meter 4 for detecting an intake air amount (intake air amount) is provided downstream of the air cleaner 3. A throttle valve 5 is provided downstream of the air flow meter 4 in the intake passage 2, and the opening degree of the throttle valve 5 is determined by the driving force of a torque motor 19 connected to a rotation shaft 5 a of the throttle valve 5. The throttle opening TA is controlled, and the amount of intake air supplied to the internal combustion engine 1 is adjusted. The actual throttle opening TA of the throttle valve 5 is detected by a throttle opening sensor 16. In addition,
Even during idling, the actual throttle opening TA is controlled by the driving force of the torque motor 19, whereby the intake air amount GN is controlled and feedback control is performed so that the engine speed NE matches the target idle speed. Further, the intake passage 2 is connected to each cylinder of the internal combustion engine 1 via an intake manifold 6, and intake air from the intake passage 2 is distributed and supplied to each cylinder via the inside of the intake manifold 6.

Intake manifold 6 is provided with an injector 7 corresponding to each cylinder, and fuel injected from each injector 7 is mixed with intake air and supplied to each cylinder. This air-fuel mixture is introduced into the combustion chamber 9 of each cylinder as the intake valve 8 opens and closes, is burned by the ignition of a spark plug 10, pushes down a piston 11, and applies torque to a crankshaft 12. The exhaust gas after combustion is discharged to the outside via an exhaust passage 14 with opening and closing of an exhaust valve 13. A crank angle sensor 15 is provided at a position close to the crankshaft 12, and a pulse signal is output from the crank angle sensor 15 at every 30 ° CA (Crank Angle).

Reference numeral 20 denotes an ECU (Electronic Control Unit:
The ECU 20 controls the driving of the injector 7 based on the intake air amount GN signal detected by the air flow meter 4 and the engine speed NE signal detected by the crank angle sensor 15, and controls the throttle opening sensor CPU that controls opening and closing of the throttle valve 5 based on the actual throttle opening TA signal detected by the accelerator pedal 16 and the accelerator opening Ap signal detected by the accelerator opening sensor 18 based on the amount of depression of the accelerator pedal 17.
The microcomputer mainly comprises a microcomputer 21, a ROM 22, a RAM 23, and the like.

Next, the configuration of the ECU 20 and its surroundings will be described in more detail with reference to FIG.

In the ECU 20, a CPU 21 reads an intake air amount GN signal, an engine speed NE signal, an actual throttle opening degree TA signal, an accelerator opening degree Ap signal, and the like, and requests each time according to the operating state of the internal combustion engine 1. This is a well-known central processing unit that calculates a fuel injection amount of the injector 7 and a target throttle opening TTP, which is a target command value of the throttle valve 5 by the torque motor 19, and the like.

The ROM 22 is a so-called program memory in which various control programs for controlling the operating state of the internal combustion engine 1, that is, a fuel injection control program, a throttle control program, and the like are stored in advance.
The CPU 21 executes various arithmetic processes in accordance with the program stored in the ROM 22. Also, RA
M23 is a so-called data memory that temporarily stores input / output data of various sensors, calculation processing data by the CPU 21, and the like.

The injector drive circuit 24 has an intake air amount GN
This is a circuit for driving the injector 7 by forming a signal of a predetermined pulse width corresponding to the fuel injection amount calculated through the CPU 21 based on the signal and the engine speed NE signal. As a result, an amount of fuel corresponding to the calculated fuel injection amount is injected and supplied from the injector 7 to each cylinder of the internal combustion engine 1. The A / D conversion circuit 27 converts the read intake air amount GN signal, actual throttle opening degree TA signal, accelerator opening degree Ap signal, cooling water temperature THW signal, and the like into an A / D signal.
This is a circuit for converting (analog-digital) and outputting the result to the CPU 21.

In the CPU 21, the target throttle opening TTP of the throttle valve 5 by the torque motor 19 and the throttle opening sensor 16
In response to the deviation from the actual throttle opening TA, the control duty (control amount) as a duty ratio signal subjected to PWM (pulse width modulation) conversion to reduce the deviation is calculated and output to the motor drive circuit 30. Is done. Then, the control current DU PWM-converted by the motor drive circuit 30
The torque motor 19 is driven by TY, and the actual throttle opening TA detected by the throttle opening sensor 16 is adjusted so as to finally coincide with the target throttle opening TTP.

Next, the configuration of the throttle control device for the internal combustion engine will be described with reference to FIGS.

2 and 3, the accelerator pedal 1
An accelerator opening sensor 18 is provided in 7, and the accelerator pedal 17 is connected to an accelerator lever 41. The accelerator lever 41 is connected to the accelerator return spring 4
The accelerator pedal 17 is urged in the return direction (clockwise direction) by the accelerator pedals 2a and 42b. Accelerator pedal 1
7 is not operated (accelerator OFF), the accelerator lever 41 is pressed by the accelerator return springs 42a, 4b.
2b, it is held in a state of contact with the accelerator fully closed stopper 43. While the internal combustion engine 1 is operating, the position of the accelerator lever 41 based on the operation amount of the accelerator pedal 17 is detected by the accelerator opening sensor 18 as the accelerator opening Ap.

On the other hand, a valve lever 44 is connected to the rotation shaft 5a of the throttle valve 5, and this valve lever 44
Is urged in the opening direction of the throttle valve 5 (upward in FIG. 2) by the retreat running spring 45. For this reason, the motor OFF (torque motor 19) shown in FIG.
When the power is turned off, the retreat running spring 45 holds the valve lever 44 at the intermediate stopper position where it contacts the intermediate lever 47. At this time, the intermediate lever 47
Is biased by the valve return spring 48 in the closing direction of the throttle valve 5 (downward in FIG. 2), and is in contact with the intermediate stopper 49.

That is, the pulling force of the valve return spring 48 is set to be larger than the pulling force of the retreat running spring 45. Therefore, when the motor is turned off as shown in FIG. 2B, the pulling force of the valve return spring 48 overcomes the pulling force of the retreat running spring 45, and the intermediate lever 47 comes into contact with the intermediate stopper 49 and is held. Is held at the intermediate stopper position (actual throttle opening TA = about 3 °) regulated by the intermediate stopper 49.

On the other hand, during the normal control (motor ON) shown in FIG. 2A, the torque motor 19 rotates forward or reverse according to the operation amount of the accelerator pedal 17, and the actual throttle opening TA of the throttle valve 5 Is adjusted, and the actual throttle opening TA of the throttle valve 5 at that time is detected by the throttle opening sensor 16. At this time, when increasing the actual throttle opening TA, the torque motor 19 is required.
When the motor motor on the positive side is supplied to the motor and the torque motor 19 is rotated forward, as shown in FIG.
4, the intermediate lever 47 is pushed up against the pulling force of the valve return spring 48, and the throttle valve 5 is driven in the opening direction. Conversely, when the actual throttle opening TA is reduced, a negative motor current is supplied to the torque motor 19 and the torque motor 19 is rotated in the reverse direction.
The valve lever 44 is lowered, and the throttle valve 5 is driven in the closing direction. When the throttle lever 5 is driven in the closing direction after the intermediate lever 47 is brought into contact with the intermediate stopper 49, the valve lever 44 is lowered against the pulling force of the retreating spring 45, and the throttle valve 5 is fully closed. When the valve lever 44 is closed to the stopper position (actual throttle opening degree TA = 0 °), the throttle fully closed stopper 4
6 to prevent further rotation.

Next, the structure of the torque motor 19 connected to the rotary shaft 5a of the throttle valve 5 used in the throttle control device for an internal combustion engine according to one embodiment of the present invention will be described with reference to FIGS. This will be described with reference to FIG. FIG. 5 is a diagram showing the torque motor 19 shown in FIG.
FIG. 3 is a view taken in the direction of arrow A with 3 removed.

As shown in FIG. 4, a throttle valve 5 is rotatably supported by bearings 61 and 62 on a throttle body 60 disposed in the middle of the intake passage 2. The throttle valve 5 is formed in a disk shape, and is fixed to the rotating shaft 5a with screws. By rotating the throttle valve 5 together with the rotation shaft 5a, the flow passage area of the intake flow passage 60a formed by the inner wall of the throttle body 60 is adjusted, and the amount of intake air passing through the intake passage 2 is controlled. You.

A valve lever 44 is press-fitted and fixed to one end of the rotary shaft 5a of the throttle valve 5, and is rotated together with the rotary shaft 5a. This valve lever 4
The fully closed position of the throttle valve 5 is defined by the contact of the throttle valve 4 with the throttle fully closed stopper 46. In addition,
By changing the screwing amount of the throttle fully closed stopper 46, the fully closed position of the throttle valve 5 is adjusted. In FIG. 4, the retreat running spring 45 and the like are omitted.

The throttle opening sensor 16 is disposed further on the end side of the rotary shaft 5a than the valve lever 44.
It comprises a contact portion 16a, a substrate 16b coated with a resistor, and a housing 16c. The contact portion 16a is press-fitted into the rotating shaft 5a, and is rotated together with the rotating shaft 5a. The board 16b is fixed to the housing 16c, and the contact portion 16a slides on the resistor applied to the board 16b. A constant voltage of 5 [V] is applied to the resistor applied to the substrate 16b. The sliding position between the resistor and the contact portion 16a is changed according to the opening of the throttle valve 5, and the output voltage value is changed. Is varied. The output voltage value from the throttle opening sensor 16 is input to the ECU 20, and the actual throttle opening TA of the throttle valve 5 is detected.

Further, as shown in FIGS. 4 and 5, the torque motor 19 is connected to the other end of the rotating shaft 5a by a rotor 65, a core 69, and a pair of solenoids 70 and 75. The end of the torque motor 19 is covered by a cover 63. The rotor 65 is composed of an iron core 66 and permanent magnets 67 and 68 press-fitted and fixed to the rotating shaft 5a, and is rotatably housed in a housing hole 69a formed by the inner wall of the core 69. The iron core 66 is formed in a cylindrical shape, and is press-fitted and fixed to the other end of the rotating shaft 5a. The permanent magnets 67 and 68 are formed in an arc shape, and
Are attached and fixed at equal intervals on the outer periphery of. Since the rotation range of the throttle valve 5 is usually 90 ° or less, the arc length of the permanent magnets 67 and 68 is long enough to allow a torque capable of rotating the rotor 65 within the rotation range of the throttle valve 5. Good. The permanent magnets 67 and 68 are neodymium-based.
A so-called samarium-cobalt system that generates high magnetic force,
Rare earth magnets are employed.

The core 69 is made of a thin plate made of a magnetic material.
The rotor 65 is rotatably housed in the housing hole 69a. The core 69 is formed in a slotless manner around the rotor 65 without any break. The solenoids 70 and 75 are formed by winding coils 72 and 77 around iron cores 71 and 76, respectively, and are press-fitted and fixed to a core 69. Coil 72, 7
7 is supplied with a control current from a pin 81 embedded in a connector 80. Also, the valve return spring 48
Has one end fixed to the iron core 66 and the other end fixed to the screw 64, and the valve return spring 48 urges the throttle valve 5 to the closed side.

Next, E used in the throttle control device for the internal combustion engine according to one embodiment of the embodiment of the present invention.
Referring to FIGS. 7, 8 and 9, based on the block diagram of FIG. 6 showing the processing procedure of the throttle control in the CPU 21 in the CU 20, FIG.

In FIG. 6, first, in a target throttle speed calculation process S1, as will be described later, a target throttle opening TTP set based on various sensor signals and an actual throttle opening TA from the throttle opening sensor 16 are determined. A target throttle speed ΔTTP is calculated based on the deviation.
At the same time, in the actual throttle speed calculation process S2, the actual throttle opening TA from the throttle opening sensor 16 is differentiated to calculate the actual throttle speed ΔTA. Next, in the acceleration torque calculation processing S3, the difference between the target throttle speed ΔTTP calculated in the preceding stage and the actual throttle speed ΔTA is multiplied by the inertia J of the throttle control system, and the acceleration torque [N ·
m] is calculated.

In the friction torque calculation processing S4, the friction torque of the throttle control system by the bearings 61, 62 and the like is calculated from the target throttle opening TTP and the actual throttle opening TA according to the friction state at that time. In the present embodiment, as shown in the map of FIG.
Bearing 6 according to the actual throttle speed ΔTA
1,62, etc., the friction torque of the throttle control system [N ·
m] is calculated. Then, in the spring torque calculation processing S5, as shown in the map of FIG.
Corresponds to the valve return spring 48 on the opening side larger than the intermediate stopper position, and the actual throttle opening TA
Is smaller than the intermediate stopper position, the spring torque [N · m] of the throttle control system corresponding to the retreat running spring 45 is calculated. Here, the actual throttle opening T
While calculating the spring torque in accordance with A, in order to further improve the responsiveness, according to the target throttle opening TTP or the predicted throttle opening (= actual throttle opening + actual throttle speed × predetermined time). The spring torque may be calculated. Then, the acceleration torque, friction torque and spring torque calculated in the preceding stage are added to calculate the required torque TR [N · m] of the torque motor 19.

In the motor current calculation process S6, as shown in the map of FIG. 9, the required torque TR [N.multidot.N] calculated in the preceding stage based on the actually measured value using the inverse model formula of TR = f (TA, IM). m] as a parameter, and the motor current IM [A] required to generate each required torque is determined by the actual throttle opening TA
It is calculated according to [°]. Here, the intermediate value in the map is calculated by an interpolation operation. FIG. 9A is a map for calculating the positive motor current IM [A] when the required torque TR [N · m] is on the positive side.
(B) is a map for calculating the negative motor current IM [A] when the required torque TR [N · m] is negative.
As described above, the motor current IM may have different characteristics due to the difference in the flow of the magnetic flux in the torque motor 19 between the positive side and the negative side.

In the voltage conversion process S7, the converted voltage obtained by converting the motor current IM [A] calculated in the preceding stage by a resistance value such as a motor coil resistance and a wiring (wire harness) resistance specific to the torque motor 19 is obtained. Is calculated.
Further, in the back electromotive voltage calculation processing S8, the back electromotive voltage is calculated according to the motor current IM [A] and the actual throttle opening TA [°] calculated in the preceding stage. Then, the required voltage VM [V] of the torque motor 19 is calculated by adding the converted voltage of the motor current IM calculated in the previous stage and the back electromotive voltage.
Next, in the required duty calculation processing S9, the required voltage VM [V] calculated in the preceding stage is multiplied by (100 / VB) and P is calculated.
A required DUTY of the torque motor 19 as a duty ratio signal converted by WM (pulse width modulation) is calculated. VB is the power supply voltage of the torque motor 19.

Further, in the error correction amount calculation processing S10, a correction amount for correcting an error between the model and the actual machine is calculated as described later. This correction amount is added to the request DUTY calculated in the previous stage, and is set as the control DUTY. This control DUTY is output to the motor drive circuit 30 so that the torque motor 19 is driven, and the actual throttle opening TA detected by the throttle opening sensor 16 is finally adjusted to match the target throttle opening TTP. Is done.

Next, E used in a throttle control device for an internal combustion engine according to one embodiment of the present invention will be described.
Referring to FIG. 11, a description will be given of a specific processing procedure of the target throttle speed calculation processing S1 in the CPU 21 of the CU 20 with reference to FIG. Here, FIG. 11 shows the target throttle opening TTP and the actual throttle opening T.
6 is a map of two (plural) different characteristics for calculating a target throttle speed ΔTTP according to a deviation from A.
This target throttle speed calculation routine is repeatedly executed by the CPU 21 in the ECU 20 at predetermined time intervals.

In this embodiment, two different characteristic maps are set as shown in FIG. That is, when the actual throttle opening TA is larger than the intermediate stopper position, the throttle valve 5 is easily moved in the closing direction under the influence of the urging force of the valve return spring 48. Conversely, when the actual throttle opening TA is at the intermediate stopper position. When the throttle valve 5 is smaller than the lower limit, the throttle valve 5 is designed to cope with the structural characteristic that the throttle valve 5 is easily moved in the opening direction under the influence of the urging force of the retreat traveling spring 45. Note that the target throttle opening TTP and the actual throttle opening TA
There may be one map for calculating the target throttle speed ΔTTP according to the deviation from the above.

In FIG. 10, first, in step S101,
It is determined whether the actual throttle opening TA is equal to or greater than the intermediate stopper position. When the determination condition of step S101 is satisfied, that is, when the actual throttle opening TA is on the opening side equal to or more than the intermediate stopper position, the process proceeds to step S102, and it is determined whether the target throttle opening TTP is equal to or more than the actual throttle opening TA. You. If the determination condition of step S102 is satisfied, that is, if the target throttle opening TTP is greater than the actual throttle opening TA and the actual throttle opening TA is in a direction away from the intermediate stopper position, step S10 is performed.
3, the target throttle speed ΔTTP for relatively steep opening direction control is calculated according to the deviation between the target throttle opening TTP and the actual throttle opening TA from the map A shown in FIG. finish.

Here, when the determination condition of step S102 is not satisfied, that is, when the target throttle opening TTP is smaller than the actual throttle opening TA and the actual throttle opening TA is in the direction approaching the intermediate stopper position, step S10 is performed.
4, the target throttle speed ΔTTP for relatively gentle closing direction control is calculated according to the deviation between the target throttle opening TTP and the actual throttle opening TA from the map B shown in FIG. finish.

On the other hand, when the determination condition of step S101 is not satisfied, that is, when the actual throttle opening TA is less than the intermediate stopper position and is on the closed side, the process proceeds to step S105.
It is determined whether the target throttle opening TTP is equal to or greater than the actual throttle opening TA. If the determination condition in step S105 is satisfied, that is, if the target throttle opening TTP is as large as the actual throttle opening TA or more and the actual throttle opening TA is in a direction approaching the intermediate stopper position, step S106 is performed.
The target throttle speed ΔTTP for relatively gentle opening direction control is calculated according to the deviation between the target throttle opening TTP and the actual throttle opening TA from the map B shown in FIG. 11, and this routine ends. I do.

Here, when the determination condition of step S105 is not satisfied, that is, when the target throttle opening TTP is smaller than the actual throttle opening TA and the actual throttle opening TA is in a direction away from the intermediate stopper position, step S105 is executed.
The routine proceeds to 107, where the target throttle speed ΔTTP for relatively steep closing direction control is calculated according to the deviation between the target throttle opening TTP and the actual throttle opening TA from the map A shown in FIG. finish.

Next, E used in the throttle control device for the internal combustion engine according to one embodiment of the embodiment of the present invention.
Error correction amount calculation processing S in CPU 21 in CU 20
This will be described with reference to the flowchart of FIG. This error correction amount calculation routine is repeatedly executed by the CPU 21 in the ECU 20 at predetermined time intervals.

In FIG. 12, in step S201,
It is determined whether the target throttle opening TTP exceeds the actual throttle opening TA. When the determination condition of step S201 is satisfied, that is, when the target throttle opening TTP is larger than the actual throttle opening TA, the process proceeds to step S202, and the actual throttle opening TA is set to the target throttle opening T.
It is determined whether the vehicle is approaching the TP. Step S202
Is not satisfied, that is, when the deviation between the actual throttle opening TA and the target throttle opening TTP is increasing, the process proceeds to step S203, and the current offset current Ioffset as an error correction amount is set as a predetermined current. ΔIof
fset is added to be the next offset current Ioffset,
This routine ends.

On the other hand, when the determination condition of step S201 is not satisfied, that is, when the target throttle opening TTP is equal to or less than the actual throttle opening TA, the process proceeds to step S204, and the target throttle opening TTP is reduced to the actual throttle opening TA.
Is determined. When the determination condition of step S204 is satisfied, that is, when the target throttle opening TTP is equal to the actual throttle opening TA, the process proceeds to step S205, and the current offset current Ioffset as the error correction amount is set.
Is set as the next offset current Ioffset, and this routine ends.

On the other hand, if the determination condition of step S204 is not satisfied, that is, if the target throttle opening TTP is smaller than the actual throttle opening TA, the process proceeds to step S206, where the actual throttle opening TA becomes equal to the target throttle opening TTP.
Is determined to be approaching. When the determination condition of step S206 is not satisfied, that is, when the deviation between the actual throttle opening TA and the target throttle opening TTP is increasing, the process proceeds to step S207, and a predetermined value is determined from the current offset current Ioffset as the error correction amount. ΔIoffs as current
The value of et is subtracted to be the next offset current Ioffset, and this routine ends. When the determination condition of step S202 or step S206 is satisfied, that is, when the deviation between the actual throttle opening TA and the target throttle opening TTP is reduced, the process proceeds to step S205, and the error correction amount is set as described above. Current offset current Ioffs
et is directly used as the next offset current Ioffset, and this routine ends.

As described above, the throttle control apparatus for an internal combustion engine according to the present embodiment has a target throttle opening TT as a target of the throttle valve 5 set based on various sensor signals.
Torque calculating means for achieving a required torque TR of the torque motor 19 in accordance with a deviation between P and the actual throttle opening TA which is the actual opening of the throttle valve 5, the torque calculating means being achieved by the CPU 21 in the ECU 20; A control duty as a control amount for making the actual throttle opening TA equal to the target throttle opening TTP is calculated according to the motor current IM calculated from the required torque TR calculated by the means and the actual throttle opening TA. CPU 2 in ECU 20
1 and the CPU 21 and the motor drive circuit 30 in the ECU 20 that drive the torque motor 19 by the control duty calculated by the control amount calculating means and control the actual throttle opening TA. And throttle control means to be achieved.

That is, in the electronic throttle system using the torque motor 19, although the number of parts is small, the mechanism is simplified and the friction can be reduced, the actual throttle opening TA with respect to the target throttle opening TTP is affected by inertia and the like. Instead, overshoot tends to occur. Therefore, the control DU as a control amount for matching the actual throttle opening TA with the target throttle opening TTP.
TY is calculated according to the motor current IM necessary for generating the required torque TR in consideration of the inertia of the torque motor 19 in the throttle control system. As a result, the non-linear torque characteristic of the torque motor 19 is absorbed, so that accurate throttle control can be performed, and the follow-up stability of the actual throttle opening TA with respect to the target throttle opening TTP can be improved.

In the throttle control device for an internal combustion engine according to the present embodiment, the torque calculation means achieved by the CPU 21 in the ECU 20 determines whether or not the target throttle opening TTP and the actual throttle opening TA are different from each other. Degree TTP
Target throttle speed Δ, which is the amount of change per unit time
The TTP is calculated, and the required torque TR is calculated by performing feedback control so that the actual throttle speed ΔTA, which is the amount of change in the actual throttle opening TA per unit time, matches the target throttle speed ΔTTP. In other words, feedback control is performed so that the actual throttle speed ΔTA matches the target throttle speed ΔTTP calculated according to the difference between the target throttle opening TTP and the actual throttle opening TA, so that the inertia of the throttle control system is reduced. The influence is removed and the required torque TR of the torque motor 19 is accurately calculated.

In the throttle control device for an internal combustion engine according to the present embodiment, the target throttle speed ΔTTP has a non-linear characteristic. That is, as shown in the map of FIG. 11, the target throttle opening TTP and the actual throttle opening T
The target throttle speed ΔTTP depends on the magnitude of the deviation from A.
Is a non-linear characteristic such that the rate of increase of As a result, the actual throttle opening T is added to the target throttle opening TTP.
Since the change in the opening degree is controlled to be slower as A approaches, the stability of following the actual throttle opening degree TA with respect to the target throttle opening degree TTP can be improved.

Further, in the throttle control apparatus for an internal combustion engine according to the present embodiment, when the control amount calculating means achieved by the CPU 21 in the ECU 20 calculates the control duty as the control amount, the inertia force and friction in the throttle control system are calculated. It reflects the torque, spring torque, and back electromotive voltage. In other words, the torque motor 19 is driven based on the control duty in which the inertia force, the friction torque, the spring torque, and the back electromotive force in the throttle control system are taken into account, so that the target throttle opening T
The tracking stability of the actual throttle opening TA with respect to TP can be improved.

The throttle control apparatus for an internal combustion engine according to the present embodiment has a characteristic that the motor current IM is different between the positive side (forward rotation) and the negative side (reverse rotation). That is, FIG.
According to the map, motor currents IM having different magnitudes corresponding to the predetermined required torque TR are obtained for the same actual throttle opening TA. Thereby, for example, the motor current IM for coping with the difference in the magnetic flux flow on the positive side / negative side can be calculated from a unique shape such as the structure of the torque motor 19 in the rotational direction not being symmetrical. The tracking stability of the actual throttle opening TA with respect to the opening TTP can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an internal combustion engine to which an internal combustion engine throttle control device according to an embodiment of the present invention is applied and peripheral devices thereof.

FIG. 2 is a schematic diagram showing a main configuration of a throttle control device for an internal combustion engine according to an example of an embodiment of the present invention.

FIG. 3 is a perspective view showing a main configuration of a throttle control device for an internal combustion engine according to an example of the embodiment of the present invention.

FIG. 4 is a cross-sectional view showing a configuration of a torque motor connected to a rotary shaft of a throttle valve used in a throttle control device for an internal combustion engine according to one embodiment of the present invention. .

FIG. 5 is an arrow view of the torque motor of FIG. 4 with the cover removed and viewed from the direction A.

FIG. 6 is an EC used in a throttle control device for an internal combustion engine according to an embodiment of the present invention.
FIG. 9 is a block diagram showing a processing procedure of throttle control in a CPU in U.

FIG. 7 is a map for calculating a friction torque from an actual throttle speed in the friction torque calculation processing of FIG. 6;

FIG. 8 is a map for calculating a spring torque from an actual throttle opening in the spring torque calculation processing of FIG. 6;

FIG. 9 is a map for calculating a motor current from an actual throttle opening and a required torque in the motor current calculation processing of FIG. 6;

FIG. 10 is a flowchart illustrating a specific processing procedure of a target throttle speed calculation processing of FIG. 6;

FIG. 11 is a map for calculating a target throttle speed from a deviation between the target throttle opening and the actual throttle opening in FIG.

FIG. 12 is a flowchart illustrating a specific processing procedure of the error correction amount calculation processing of FIG. 6;

FIG. 13 is a characteristic diagram showing a relationship between an actual throttle opening and a motor torque when a throttle valve is driven using a torque motor in a conventional throttle control device, using a motor current as a parameter.

[Explanation of symbols]

 Reference Signs List 1 internal combustion engine 5 throttle valve 16 throttle opening sensor 18 accelerator opening sensor 19 torque motor 20 ECU (electronic control unit)

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[Procedure amendment]

[Submission date] April 2, 1998

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0046

[Correction method] Change

[Correction contents]

In FIG. 12, in step S201,
It is determined whether the target throttle opening TTP exceeds the actual throttle opening TA. When the determination condition of step S201 is satisfied, that is, when the target throttle opening TTP is larger than the actual throttle opening TA, the process proceeds to step S202, and the actual throttle opening TA is set to the target throttle opening T.
It is determined whether the vehicle is approaching the TP. Step S202
Is not satisfied, that is, the deviation between the actual throttle opening TA and the target throttle opening TTP is not reduced.
If it has not changed or is expanding, step S2
03 proceeds to, are subject to ΔIoffset as a predetermined current to the previous offset current Ioffset as error correction now
This is the offset current Ioffset, and this routine ends.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0047

[Correction method] Change

[Correction contents]

On the other hand, when the determination condition of step S201 is not satisfied, that is, when the target throttle opening TTP is equal to or less than the actual throttle opening TA, the process proceeds to step S204, and the target throttle opening TTP is reduced to the actual throttle opening TA.
Is determined. When the determination condition of step S204 is satisfied, that is, when the target throttle opening TTP is equal to the actual throttle opening TA, the process proceeds to step S205, and the previous offset current Ioffset as the error correction amount is set.
Is used as the current offset current Ioffset as it is, and this routine ends.

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0048

[Correction method] Change

[Correction contents]

On the other hand, if the determination condition of step S204 is not satisfied, that is, if the target throttle opening TTP is smaller than the actual throttle opening TA, the process proceeds to step S206, where the actual throttle opening TA becomes equal to the target throttle opening TTP.
Is determined to be approaching. The determination condition of step S206 is not satisfied, that is, the deviation between the actual throttle opening TA and the target throttle opening TTP changes without reducing.
If not, or conversely, if it is enlarged, step S207
To the previous offset current I as an error correction amount.
ΔIoffset as a predetermined current from the offset is set to the current is subtracted <br/> offset current Ioffset, the routine ends. When the determination condition of step S202 or step S206 is satisfied, that is, when the deviation between the actual throttle opening TA and the target throttle opening TTP is reduced, the process proceeds to step S205, and the error correction amount is set as described above. the last offset current Ioffset is directly used as this <br/> offset current Ioffset, the routine ends.

Claims (5)

[Claims] A required torque of a torque motor is determined in accordance with a deviation between a target throttle opening of a throttle valve set based on various sensor signals and an actual throttle opening which is an actual opening of the throttle valve. A torque calculating means for calculating, and a method for matching the actual throttle opening with the target throttle opening in accordance with a motor current calculated from the required torque calculated by the torque calculating means and the actual throttle opening. Control amount calculating means for calculating a control amount, and throttle control means for driving the torque motor with the control amount calculated by the control amount calculating means and controlling the actual throttle opening. Control device for an internal combustion engine. 2. The torque calculation means calculates a target throttle speed, which is a change amount of the target throttle opening per unit time, according to the deviation, and calculates a target throttle speed by a change amount of the actual throttle opening per unit time. 2. The throttle control device for an internal combustion engine according to claim 1, wherein the required torque is calculated by performing feedback control so that a certain actual throttle speed matches the target throttle speed. 3. The throttle control device for an internal combustion engine according to claim 2, wherein the target throttle speed has a non-linear characteristic. 4. The control amount calculating means, when calculating the control amount, reflects at least one of an inertial force, a friction torque, a spring torque, and a back electromotive force in a throttle control system. Any one of items 1 to 3
7. A throttle control device for an internal combustion engine according to claim 1. 5. The motor current according to claim 1, wherein said motor current has different characteristics between a positive side and a negative side.
The throttle control device for an internal combustion engine according to any one of the above.