JPH11270363A - Throttle control device of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve follow-up stability of opening of a throttle valve in an electronic throttle system using a torque motor. SOLUTION: An electronic throttle system using a torque motor 19 is simplified in structure with a small number of part items and has a tendency to make it hard to stabilize opening of a throttle valve by an amount that a reduction gear train is not interposed and to make it easy to overshoot. Consequently, a controlled variable to make actual throttle opening TA coincide with a target throttle opening is computed in accordance with a motor electric current required for the torque motor 19 in a throttle control system and counter electromotive voltage computed by the motor electric current and the actual throttle opening TA. Accordingly, It becomes possible to carry out precise throttle control in consideration of a non-linear counter electromotive voltage characteristic of the torque motor 19.

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]

By the way, the back electromotive force characteristic of a DC (direct current) motor is as follows: Ve = Ke × (d
θ / dt). here,
Ve is the back electromotive voltage, Ke is the back electromotive voltage constant, (dθ / dt)
Is the actual throttle speed as the amount of change in the actual throttle opening per unit time. That is, the actual throttle speed (d
It shows that the back electromotive voltage Ve can be obtained almost linearly according to (θ / dt).

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 back electromotive force characteristic of this torque motor is such that the back electromotive voltage Ve [V] is a two-dimensional function of the motor current i [A] and the actual throttle opening θ [°] Ve = f.
(I, θ). In addition, since the drive shaft of the torque motor is directly connected to the rotation shaft of the throttle valve, the opening of the throttle valve is difficult to stabilize because the reduction gear train is not interposed between the drive shaft and accuracy is reduced. Become.

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 motor current is 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, and is calculated from the motor current and the actual throttle opening. Is calculated by the control amount calculating means in accordance with the back electromotive voltage. In other words, in an electronic throttle system using a torque motor, the number of parts is small, the mechanism is simplified, and it is difficult to stabilize the opening of the throttle valve by the absence of the reduction gear train, and it tends to overshoot. is there. For this reason, the control amount for matching the actual throttle opening to the target throttle opening depends on the motor current required for the torque motor in the throttle control system and the back electromotive voltage calculated from the motor current and the actual throttle opening. Is calculated. This enables accurate throttle control in consideration of the non-linear back electromotive force characteristic of the torque motor, and improves the follow-up stability of the actual throttle opening with respect to the target throttle opening.

According to a second aspect of the present invention, the amount of change per unit time of the magnetic flux density calculated by the control amount calculating means as a two-dimensional function of the motor current and the actual throttle opening is calculated. It is calculated based on As described above, since the actual back electromotive voltage is obtained from the parameters which can be calculated in advance, the correction amount of the throttle control corresponding to the back electromotive voltage is accurately calculated. This enables accurate throttle control in consideration of the non-linear back electromotive force characteristic of the torque motor, and improves the follow-up stability of the actual throttle opening with respect to the target throttle opening.

According to a third aspect of the present invention, when the target throttle opening is separated from the actual throttle opening by the control amount calculating means, the torque motor is controlled by the correction amount corresponding to the back electromotive force. When the control amount for driving is corrected, overshoot is promoted, so that the correction amount corresponding to the back electromotive voltage is set to zero and the correction corresponding to the back electromotive voltage is not performed, or the correction based on the back electromotive voltage is performed. You. As a result, the actual throttle opening quickly approaches the target throttle opening, and overshoot is suppressed, so that the stability of the actual throttle opening following the target throttle opening in throttle control can be improved.

In the throttle control device for an internal combustion engine according to the present invention, the control amount calculating means changes the reflection ratio for the correction amount corresponding to the back electromotive voltage in accordance with the deviation between the target throttle opening and the actual throttle opening. This can improve the follow-up stability of the actual throttle opening with respect to the target throttle opening while suppressing overshoot in throttle control.

According to a fifth aspect of the present invention, the back electromotive voltage is separated into a change due to the motor current and a change due to the actual throttle opening by the control amount calculating means, and a correction amount corresponding to each change is provided. One of the reflection ratios to the target is relatively reduced. In other words, by changing the reflection ratio for the correction amount corresponding to the change in the back electromotive voltage, it is possible to correspond to the throttle control characteristic of the actual electronic throttle system. The stability of following the opening can be improved.

In the throttle control apparatus for an internal combustion engine according to the present invention, the back throttle voltage is changed to the actual throttle opening by the control amount calculating means, and the predicted throttle opening predicted in advance from the target throttle speed and the actual throttle speed. , The throttle control can be performed more quickly and accurately, and the stability of following the actual throttle opening with respect to the target throttle opening can be improved.

[0013]

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 injectors 7 corresponding to each cylinder, and the 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, the 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 structure 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 rotary 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 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 rotating 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 provided 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 rotation 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.
So-called rare earth magnets that generate high magnetic force, such as samarium-cobalt, 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 an internal combustion engine according to one embodiment of the present invention will be described.
A description will be given based on a block diagram of FIG. 6 showing a processing procedure of the throttle control in the CPU 21 in the CU 20.

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

In the friction torque calculation processing S4, the friction torque [N · m] of the throttle control system by the bearings 61, 62, etc., based on the target throttle opening TTP and the actual throttle opening TA according to the friction state at that time. Is calculated. In the spring torque calculation processing S5, the opening side where the actual throttle opening TA is larger than the intermediate stopper position corresponds to the valve return spring 48, and the closing side where the actual throttle opening TA is smaller than the intermediate stopper position corresponds to the evacuation travel. The spring torque [N · m] of the throttle control system corresponding to the spring 45 is calculated. Here, while the spring torque is calculated according to the actual throttle opening TA, in order to further improve the responsiveness, the target throttle opening TTP or the predicted throttle opening (= the actual throttle opening + the actual throttle speed) (Predetermined time) may be used to calculate the spring torque. 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 processing S6, TR = f
Based on the measured values using the inverse model formula of (TA, IM),
Using the required torque TR [N · m] calculated in the previous stage as a parameter, the motor current IM required to generate each required torque
[A] is calculated according to the actual throttle opening TA [°]. In the voltage conversion process S7, a converted voltage is calculated 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. .

Further, in the back electromotive voltage calculation processing S8, as will be described later, the back electromotive voltage Ve is calculated in accordance with the motor current IM [A] and the actual throttle opening TA [°] calculated in the preceding stage. Back electromotive voltage correction amount C corresponding to back electromotive voltage Ve
Ve is calculated. 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 preceding stage and the back electromotive voltage correction amount CVe corresponding to the back electromotive voltage Ve. Next, in the required duty calculation processing S9, the required voltage VM [V] calculated in the preceding stage is set to (1).
00 / VB), and a required duty of the torque motor 19 as a duty ratio signal subjected to PWM (pulse width modulation) conversion is calculated. VB is the torque motor 19
Power supply voltage.

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. 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, the E used in the throttle control device for the internal combustion engine according to one embodiment of the present invention will be described.
8 and 9 based on a flowchart of FIG. 7 showing a specific processing procedure of the back electromotive voltage calculation processing S8 in the CPU 21 of the CU 20. FIG. 8 shows the magnetic flux density B [G] between the coils of the torque motor 19 according to the motor current IM [A] and the actual throttle opening TA [°].
S]. FIG. 9 shows the actual throttle opening TA with respect to the target throttle opening TTP [°].
9 is a time chart showing a back electromotive voltage Ve [V] and a back electromotive voltage correction amount CVe [V] corresponding to a transition state of [°]. Note that this back electromotive voltage calculation routine is executed every predetermined time.
It is repeatedly executed by the CPU 21 in the CU 20.

In FIG. 7, first, in step S101, the motor current IM and the actual throttle opening TA calculated in the preceding motor current calculation processing S6 are read. Next, the process proceeds to step S102, where the magnetic flux density B between the coils is obtained from the map shown in FIG. 8 obtained by solving the equation using the magnetic vector potential, B = f (IM, TA), by the finite element method. Is calculated. Note that the magnetic flux density B may be obtained by actual measurement.

Next, the process proceeds to step S103, and when there is an eddy current loss, the approximation can be easily made.
9 is calculated by the following equation (1). Here, n is the number of coil turns, S is the coil cross-sectional area, Ku
Is the eddy current constant.

[0043]

Ve = −n · S · {(dB / dt) + Ku (dB / dt)} (1) Next, the routine proceeds to step S104, where the actual throttle opening T
It is determined whether A is approaching the target throttle opening TTP. When the determination condition of step S104 is satisfied, that is, when the deviation between the target throttle opening TTP and the actual throttle opening TA is reduced as shown from time t0 to time t1 in FIG. 9, the process proceeds to step S105. The voltage value −Ve [V] obtained by inverting the sign of the back electromotive voltage Ve [V] is calculated as the electromotive voltage correction amount CVe [V], and this routine ends.

That is, from time t0 to time t1 in FIG.
The back electromotive voltage Ve acts in a direction in which no current flows, that is, a direction in which the movement of the torque motor 19 is hindered. To cope with this, the back electromotive voltage correction amount CVe [V] is corrected to cancel the back electromotive voltage Ve, and the current movement of the torque motor 19 is maintained as it is.

On the other hand, the determination condition of step S104 is not satisfied, that is, as shown after time t1 in FIG. 9, the deviation between the target throttle opening TTP and the actual throttle opening TA does not change without reducing. Alternatively, when the image is expanded, the process proceeds to step S106, and the back electromotive voltage correction amount CVe
[V] is set to the voltage value 0 [V], and this routine ends.

That is, after time t1 in FIG. 9, it is conceivable that overshoot will be promoted if the correction by the back electromotive voltage correction amount CVe [V] is executed. After time t1 in FIG. 9, the back electromotive voltage correction amount CVe [V] in step S106 may be the back electromotive voltage Ve [V]. In this case, the back electromotive voltage V is applied to the torque motor 19.
e The target throttle opening TTP
Can be suppressed from increasing after the actual throttle opening TA exceeds the above.

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; The actual throttle opening TA according to the motor current IM calculated from the required torque TR calculated by the means and the actual throttle opening TA, and the back electromotive force Ve calculated from the motor current IM and the actual throttle opening TA. Control amount calculation means achieved by the CPU 21 in the ECU 20 for calculating a control duty as a control amount for causing the control duty to coincide with the target throttle opening degree TTP, and a control duty calculated by the control amount calculation means.
The torque motor 19 is driven by the
And a throttle control means achieved by a motor drive circuit 30 and a CPU 21 in the ECU 20 that controls the ECU A.

That is, in the electronic throttle system using the torque motor 19, the number of parts is small and the mechanism is simplified, so that the opening of the throttle valve is difficult to stabilize and the overshoot is easily caused by the absence of the reduction gear train. Tend to be. For this reason, the control duty DUTY as a control amount for matching the actual throttle opening TA to the target throttle opening TTP is determined by the motor current IM required for the torque motor 19 in the throttle control system, the motor current IM and the actual throttle opening TA. Is calculated according to the back electromotive voltage Ve calculated by As a result, accurate throttle control in consideration of the non-linear back electromotive force characteristics of the torque motor 19 becomes possible, and the target throttle opening TT
The tracking stability of the actual throttle opening TA with respect to P can be improved.

In the throttle control apparatus for an internal combustion engine according to the present embodiment, the control amount calculation means achieved by the CPU 21 in the ECU 20 uses the back electromotive force Ve to change the magnetic flux density B according to the motor current IM and the actual throttle opening TA. It is calculated based on That is, the magnetic flux density B is equal to the motor current IM.
And a two-dimensional function of the actual throttle opening TA,
The amount of change in the magnetic flux density B per unit time (dB / d
The back electromotive voltage Ve is calculated based on t). As described above, since the actual back electromotive voltage Ve is obtained from the parameters which can be calculated in advance, the correction amount of the throttle control corresponding to the back electromotive voltage Ve is accurately calculated. This enables accurate throttle control in consideration of the non-linear back electromotive force characteristics of the torque motor 19,
Actual throttle opening T with respect to target throttle opening TTP
The tracking stability of A can be improved.

The throttle control device 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 is in a direction in which the target throttle opening TTP and the actual throttle opening TA are separated from each other, Control DU
The back electromotive voltage correction amount CVe as the correction amount corresponding to the back electromotive voltage Ve reflected on TY is zero or the direction of correction of the back electromotive voltage correction amount CVe corresponding to the back electromotive voltage Ve is reversed. That is, when the target throttle opening degree TTP and the actual throttle opening degree TA are in a direction in which they are separated from each other, the back electromotive force Ve
If the control DUTY is corrected by the back electromotive voltage correction amount CVe as the correction amount corresponding to the back electromotive voltage, the overshoot is promoted.
Ve is set to zero, and no correction corresponding to the back electromotive voltage Ve is performed.
Alternatively, the correction by the back electromotive voltage Ve is executed. As a result, the actual throttle opening TA becomes smaller than the target throttle opening TT.
P is quickly approached, and overshoot is suppressed, so that the follow-up stability of the actual throttle opening TA with respect to the target throttle opening TTP in the throttle control can be improved.

Next, E used in the throttle control device for the internal combustion engine according to one embodiment of the present invention will be described.
A description will be given based on a flowchart of FIG. 10 showing a modified example of a specific processing procedure of the back electromotive voltage calculation processing S8 in the CPU 21 of the CU 20. FIG. 10 differs from FIG. 7 only in the part corresponding to the processing in step S105 in FIG. 7 described above, and only that part will be described in detail. The back electromotive voltage calculation routine is executed every predetermined time by the CPU 2 in the ECU 20.
1 is repeatedly executed.

In FIG. 10, steps S201 to S204 are described in the same manner as steps S101 to S104 in FIG. When the determination condition of step S204 is satisfied, that is, when the difference between the target throttle opening TTP and the actual throttle opening TA is reduced, the process proceeds to step S205, and the deviation Δθ is changed from the target throttle opening TTP to the actual throttle opening TA. Is calculated by subtracting Next, the process proceeds to step S206,
The reflection rate α corresponding to the deviation Δθ calculated in 205 is calculated from the map. In this map, the torque motor 1
9 is emphasized, and the reflection rate α is set to “1” until the absolute value of the deviation Δθ becomes a predetermined value, and the reflection rate α is gradually reduced as the deviation becomes smaller than the predetermined value. When the deviation Δθ becomes “0”, the reflection rate α also becomes “0”.

Next, the flow shifts to step S207, where the sign of the back electromotive voltage Ve [V] calculated in step S203 is inverted as the back electromotive voltage correction amount CVe [V] -Ve.
[V] is multiplied by the reflection rate α calculated in step S206 to calculate a voltage value−α · Ve [V], and this routine ends. On the other hand, when the determination condition of step S204 is not satisfied, that is, when the difference between the target throttle opening TTP and the actual throttle opening TA does not change without reducing or does not change or expands, the process proceeds to step S208. The back electromotive voltage correction amount CVe [V] is set to the voltage value 0 [V], and this routine ends.

As described above, in the throttle control device for an internal combustion engine according to the present embodiment, the control amount calculating means achieved by the CPU 21 in the ECU 20 determines the control amount calculation means according to the deviation Δθ between the target throttle opening TTP and the actual throttle opening TA. Thus, the reflection rate α to the back electromotive voltage correction amount CVe as the correction amount corresponding to the back electromotive voltage Ve is changed. For example, when the deviation Δθ between the target throttle opening TTP and the actual throttle opening TA decreases and the actual throttle opening TA approaches the target throttle opening TTP, the back electromotive voltage correction amount CVe corresponding to the back electromotive voltage Ve. Is reduced. That is, by changing the reflection ratio α to the back electromotive voltage correction amount CVe corresponding to the back electromotive voltage Ve according to the deviation Δθ, the overshoot in the throttle control is suppressed while the actual throttle opening TA with respect to the target throttle opening TTP. Tracking stability can be improved.

Next, E used in the throttle control device for the internal combustion engine according to one embodiment of the embodiment of the present invention.
A description will be given based on a flowchart of FIG. 11 showing another modified example of the specific processing procedure of the back electromotive voltage calculation processing S8 in the CPU 21 of the CU 20. This back electromotive voltage calculation routine is repeatedly executed by the CPU 21 in the ECU 20 at predetermined time intervals.

In FIG. 11, in step S301, the motor current I calculated in the preceding motor current calculation processing S6 is calculated.
M and the actual throttle opening TA are read. Next, the process proceeds to step S302, and the magnetic flux density B between the coils is calculated by solving the equation using the magnetic vector potential, B = f (IM, TA), by the finite element method as described above. Also, the change dB / dt of the magnetic flux density B can be separated into a motor current change dB (IM) / dt and an actual throttle opening change dB (TA) / dt, and the motor current change dB ( IM) / dt = f (dIM / dt, T
A), the actual throttle opening change dB (T
A) / dt = f (IM, dTA / dt).

Next, the flow shifts to step S303, where the motor current change amount Ve (I
M) is calculated by the following equation (2), and the actual throttle opening change Ve (TA) of the back electromotive voltage is calculated by the following equation (3). Where n
Is the number of coil turns, S is the coil cross-sectional area, and Ku is the eddy current constant.

[0058]

Ve (IM) = − n · S · [{dB (IM) / dt} + Ku {dB (IM) / dt}] (2)

[0059]

Ve (TA) = − n · S · [{dB (TA) / dt} + Ku {dB (TA) / dt}] (3) Next, the process proceeds to step S304, where the actual throttle is set. Opening T
It is determined whether A is approaching the target throttle opening TTP. When the determination condition of step S304 is satisfied, that is, when the deviation between the target throttle opening TTP and the actual throttle opening TA is reduced, the process proceeds to step S305,
The deviation Δθ is calculated by subtracting the actual throttle opening TA from the target throttle opening TTP. Next, step S
306, the motor current change Ve (IM) of the back electromotive voltage corresponding to the deviation Δθ calculated in step S305.
And the actual throttle opening change Ve (T
The reflection ratio γ of A) is calculated using the map. In this map, the tracking stability of the torque motor 19 is emphasized, and the reflection ratio β,
γ is constant, and the reflection ratios β and γ are gradually reduced as the value becomes smaller than a predetermined value. Then, when the deviation Δθ becomes “0”, the reflection rates β and γ also become “0”. In addition,
β ≦ γ, 0 ≦ β, γ ≦ 1, and the remainder of β and γ (1-
β) and (1-γ) are used as brakes of the hardware itself.

Next, the flow shifts to step S307, where the voltage value obtained by inverting the sign of the motor current variation Ve (IM) [V] of the back electromotive voltage calculated in step S303 as the back electromotive voltage correction amount CVe [V]. −Ve (IM) [V] to step S3
Voltage-β · V multiplied by the reflection rate β calculated in step 06
e (IM) [V] and the voltage value −Ve (TA) [V] obtained by inverting the sign of the actual throttle opening change amount Ve (TA) [V] of the back electromotive voltage calculated in step S303 to step S306.
Voltage-γ · Ve (T) multiplied by the reflection rate γ calculated in
A) [V] is added and the voltage value -β · Ve (IM) -γ ·
Ve (TA) [V] is calculated, and this routine ends.

On the other hand, if the determination condition of step S304 is not satisfied, that is, if the deviation between the target throttle opening TTP and the actual throttle opening TA does not change without reducing or does not change, or conversely increases, the process proceeds to step S308. Then, the back electromotive voltage correction amount CVe [V] is set to the voltage value 0 [V], and this routine ends. Note that the back electromotive voltage correction amount CVe [V] in step S308 is replaced by the back electromotive voltage β · Ve (IM).
+ Γ · Ve (TA) [V]. In this case,
The counter electromotive voltage β · Ve (IM) + γ · Ve is applied to the torque motor 19.
By giving the (TA) component as it is, it is possible to suppress an increase in the deviation Δθ after the actual throttle opening TA exceeds the target throttle opening TTP.

As described above, in the throttle control device for an internal combustion engine according to the present embodiment, the control amount calculating means achieved by the CPU 21 in the ECU 20 changes the back electromotive voltage Ve by the motor current change Ve (IM) by the motor current IM. And actual throttle opening T
A is separated into the actual throttle opening change amount Ve (TA) due to A, and the back electromotive voltage correction amount C as a correction amount corresponding thereto.
One of the reflection rates β and γ of Ve is relatively reduced.

That is, the back electromotive voltage Ve is the motor current variation V
e (IM) and the actual throttle opening change amount Ve (TA), and one of the reflection ratios β and γ of the back electromotive voltage correction amount CVe corresponding to each change is used as the reflection ratio γ. It is made smaller than that. In this case, the reflection ratio γ of the back electromotive voltage Ve with respect to the actual throttle opening change amount Ve (TA) is larger than the reflection ratio β with respect to the motor current change amount Ve (IM). You. That is, by changing the reflection ratios β and γ to the back electromotive voltage correction amount CVe corresponding to the change of the back electromotive voltage Ve, it is possible to correspond to the actual throttle control characteristics of the electronic throttle system, and to suppress overshoot. In addition, the stability of following the actual throttle opening TA with respect to the target throttle opening TTP can be improved.

Next, E used in the throttle control device for the internal combustion engine according to one example of the embodiment of the present invention.
Still another modification of the back electromotive voltage calculation processing S8 in the CPU 21 of the CU 20 will be described below.

The actual throttle opening T is obtained by subtracting the actual throttle speed ΔTA, which is the amount of change of the actual throttle opening TA per unit time, from the target throttle speed ΔTTP, which is the amount of change per unit time of the target throttle opening TTP.
By adding to A, a predicted throttle opening ETA is obtained,
The predicted throttle opening ETA is replaced with the actual throttle opening TA in the back electromotive voltage calculation routines of FIGS. 7, 10 and 11, thereby correcting the back electromotive voltage corresponding to the back electromotive voltage Ve necessary for throttle control. The quantity CVe can be predicted.

As described above, in the throttle control apparatus for an internal combustion engine according to the present embodiment, the control amount calculating means achieved by the CPU 21 in the ECU 20 calculates the back electromotive force Ve per unit time of the current target throttle opening degree TTP. This is calculated based on the next predicted throttle opening ETA which is predicted from the target throttle speed ΔTTP as the amount of change and the actual throttle speed ΔTA as the amount of change per unit time of the actual throttle opening TA. That is, the back electromotive force Ve is calculated based on the predicted throttle opening ETA calculated in advance in place of the actual throttle opening TA, thereby enabling quicker and more accurate throttle control, and the target throttle opening TTP.
, The follow-up stability of the actual throttle opening TA 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 flowchart showing a specific processing procedure of the back electromotive voltage calculation processing of FIG. 6;

FIG. 8 is a map for calculating a magnetic flux density from the motor current and the actual throttle opening in FIG. 7;

FIG. 9 is a time chart showing a back electromotive voltage and a back electromotive voltage correction amount corresponding to a transition state of the actual throttle opening with respect to the target throttle opening in FIG. 7;

FIG. 10 is a flowchart illustrating a modified example of the specific processing procedure of the back electromotive voltage calculation processing of FIG. 6;

FIG. 11 is a flowchart illustrating another modified example of the specific processing procedure of the back electromotive voltage calculation processing of FIG. 6;

[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)

Claims (6)

[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 to calculate, a motor current calculated from the required torque calculated by the torque calculating means and the actual throttle opening, and a back electromotive voltage calculated from the motor current and the actual throttle opening. Control amount calculating means for calculating a control amount for causing the actual throttle opening to match the target throttle opening in accordance with the control amount, and driving the torque motor with the control amount calculated by the control amount calculating means, And a throttle control means for controlling an actual throttle opening. 2. The throttle according to claim 1, wherein the control amount calculating means calculates the back electromotive voltage based on a change in magnetic flux density due to the motor current and the actual throttle opening. Control device. 3. The control amount calculating means sets a correction amount corresponding to the back electromotive force, which is reflected in the control amount, to zero or the correction amount when the target throttle opening and the actual throttle opening are in a direction away from each other. 3. The throttle control device for an internal combustion engine according to claim 1, wherein a correction direction of the correction amount corresponding to a back electromotive voltage is reversed. 4. The method according to claim 1, wherein the control amount calculation means changes a reflection rate of the correction amount corresponding to the back electromotive force in accordance with a deviation between the target throttle opening and the actual throttle opening. The throttle control device for an internal combustion engine according to any one of claims 1 to 3. 5. The control amount calculating means separates the back electromotive voltage into a change due to the motor current and a change due to the actual throttle opening, and relatively reduces one of the reflection rates. The throttle control device for an internal combustion engine according to any one of claims 1 to 4, characterized in that: 6. The control amount calculating means calculates the back electromotive force by using a target throttle speed which is a current change amount of the target throttle opening per unit time and a change amount of the actual throttle opening per unit time. The throttle control device for an internal combustion engine according to any one of claims 1 to 5, wherein the calculation is performed based on a next predicted throttle opening degree predicted from a certain actual throttle speed.