JPH0361640A - How to control an automobile control valve to the target opening degree - Google Patents

Abstract

PURPOSE:To avoid resonance by monitoring the lapse time from the switching of the output port value immediately before the interruption, in each interruption, and suspending the switching of the output port value when the accordance with the resonance time of the step motor is judged. CONSTITUTION:Judging traction control from the slip of a driving wheel, a microcomputer 104 executes interruption on the basis of the throttle opening degree detected by a detector 46 and calculates the aimed opening degree for each interruption, and a pulse train is outputted in succession into each phase coil 100-103 through the transistors 113-116 for drive, and a throttle valve is driven in the closing direction by a step motor. In the case, the lapse time from the switching to the different output port value immediately before the interruption is monitored for each interruption, and if the lapse time accords with the resonance time of the step motor, switching of the output port value is suspended. Therefore, resonance is avoided, and slip-off, etc., of the step motor can be prevented.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method of controlling a control valve of an automobile to a target opening degree, and can be employed, for example, in so-called traction control, auto cruising control, etc. It is something.

[Conventional technology]

Traction control and auto cruising control have traditionally been used in automobiles, but
For this purpose, it is essential to control a control valve such as a throttle valve of an automobile to a target opening degree.

A method for controlling the control valve of an automobile to a target opening degree uses a step motor that drives the control valve of the automobile, and a microcomputer that determines the excitation state of the step motor according to an output port value. Interrupt periodically, and for each interrupt,
A possible method is to have the microcomputer perform a comparison operation on the detected opening degree data and the target opening degree data of the control valve, and switch the output port value to a value according to the result.

According to this method, if the actual opening of the control valve does not match the target opening, the output port value of the microcomputer is switched to a different value for each interrupt, and the excitation state of the step motor is changed. is switched to a different state, thereby causing the step motor to move one step in the direction in which the opening degrees of the control valves match. On the other hand, if they match, the output port value of the microcomputer remains the same, the excitation state of the step motor is maintained as it is, and the control valve is controlled to the opening degree. Therefore, the cycle of the interrupt determines the switching timing of the phase excitation of the step motor and determines the pulse rate of the step motor.

By the way, resonance occurs in a step motor around a certain pulse rate (for example, 300 pps), and driving the step motor at this pulse rate will cause step-out, etc., so the actual pulse rate is selected to avoid that pulse rate. . In this specification, the pulse rate at which this resonance occurs is converted into a period (for example, 300 pp
3.33 m5) for s is called the resonance time. When adopting the above method, the cycle of the above interrupt is
It is selected to avoid the resonance time of the step motor.

However, in the above method, in order to improve responsiveness, it is necessary to shorten the period of the above interrupt (that is, increase the pulse rate), and in that case, multiplying the period of the above interrupt by several times will match the resonance time. I will do it.

On the other hand, since the above method is actually employed as a part of traction control, auto cruising, etc., the target opening degree data is changed as appropriate. Therefore, if the target opening data is changed after the control valve is controlled to the target opening based on certain target opening data, the actual switching interval of the phase excitation of the step motor will be equal to the period of the above-mentioned interrupt. It may become several times as large as the resonance time, and in that case, tax adjustment, etc. will be caused.

[Problem to be solved by the invention]

The present invention has been made in view of the above circumstances, and is an automobile that can improve responsiveness, always avoid resonance of the step motor, prevent step-out, etc., and enable stable control. The present invention aims to provide a method for controlling a control valve to a target opening degree.

[Means for resolving issues]

In order to solve the above problems, the present invention uses a step motor that drives a control valve of an automobile and a microcomputer that determines the excitation state of the step motor according to an output port value. An interrupt is applied to the microcomputer, and each time the microcomputer performs a comparison operation between the detected opening degree data and the target opening degree data of the control valve, the output port value is switched to a value corresponding to the result. Then, for each interrupt, the elapsed time from when the output port value was switched to a different value immediately before the interrupt is monitored, and if the elapsed time matches the resonance time of the step motor, the above Cancels switching of output port values.

[Effect]

According to the present invention, for each interrupt, the elapsed time from when the output port value was switched to a different value immediately before the interrupt is monitored, and the elapsed time matches the resonance time of the step motor. In this case, the switching of the above output port value is stopped, so even if the above interrupt cycle is shortened to improve responsiveness, the actual switching interval of the step motor's phase excitation will not always match the resonance time. , resonance of the step motor is always avoided, step-out, etc. are prevented, and stable control is possible.

〔Example〕

An example in which the method of the present invention is applied to the control of a butterfly-type throttle valve 6, which is a control valve in a throttle control device for an automobile shown in FIGS. 1 to 5, will be described below.

First, the throttle control device for an automobile shown in FIGS. 1 to 5 will be explained.

This throttle control device has a butterfly-type throttle valve 6, which is rotatably supported by a support 1, and which is linked to the operation of an accelerator pedal by a throttle shaft 2 that biases a spring in the closing direction of the throttle valve 6. Operation lever 8
is supported so as to be relatively rotatable, and is connected to a control lever 9 which is interlocked and connected to a step motor 52 serving as an actuator. A lost motion spring is interposed between the lost motion lever 7, which is fixed to the throttle shaft 2 so as to be engaged with the operating lever 8, and which exerts a spring force in the direction of engaging the operating lever 8 and the lost motion lever 7. A regulation lever 63 is supported on the support body 1 so as to be rotatable around an axis parallel to the throttle shaft 2. The regulation lever 63 is connected to rotate in one direction in response to the rotation of the lost motion lever 7 in the throttle valve closing direction when the rotation is in the throttle valve closing direction. A dash board 56 that provides damping force is connected to the dash board 56.

The throttle control device shown in FIGS. 1 to 5 will be explained in detail below.

A throttle shaft 2 is rotatably supported on a throttle body 1 as a support via bearings 3 and 4, and an intake passage 5 formed in the throttle body 1 is provided on the throttle shaft 2 to open and close it. A butterfly-type throttle valve 6 is fixed thereto.

Both ends of the throttle shaft 2 project from the throttle body 1 on both sides, and a tenth motion lever 7 is fixed to one end of the throttle shaft 2 projecting from the throttle body 1 (left side in FIG. 3). The operating lever 8 is supported so as to be relatively rotatable. Further, a control lever 9 is fixed to the other end of the throttle shaft 2 protruding from the throttle body 1 (on the right side in FIG. 3).

On one end side of the throttle shaft 2 protruding from the throttle body 1, the outer periphery of the throttle shaft 2 is cut out so as to form a pair of flat surfaces along the axis, and a rectangular portion having a substantially rectangular cross-sectional shape is formed. 2a is provided. Rectangular part 2a
includes, in order from the proximal end to the distal end thereof, a cylindrical collar 10 whose inner end abuts against the bearing 3, and a basically disc-shaped restriction abuts the outer end of the collar 10. a plate 11, a cylindrical collar 12 whose inner end is in contact with the regulation plate 11, and a tenth
A nut 13 is screwed onto the outer end of the throttle shaft 2 which is fitted with the 10th stroke lever 7 and projects from the 10th stroke lever 7.
1, a collar 12 and a tenth motion lever 7 are fixed to the throttle shaft 2.

The operating lever 8 consists of a cylindrical portion 8a coaxially surrounding a cylindrical collar 10, and a drum portion 8b fixed to the outer end of the cylindrical portion 8a, with a bearing 14 interposed therebetween. and is attached to the collar 10. Further, the axial position of the cylindrical portion 8a is regulated by a member 15 and a regulating plate 11 for a joint or a resin receiver that abuts on the outer surface of the throttle body 1. A throttle wire 16 that is pulled and driven by a throttle operating section (not shown) is wound around the drum section 8b, and an engagement piece 17 provided at one end of the throttle wire 16 is engaged with the drum section 8b. Therefore, the operating lever 8 is moved by the arrow 1 in FIG.
It is rotationally driven in the throttle valve opening direction indicated by 8. Moreover, a coil-shaped first return spring 19 that surrounds the cylindrical portion 8a is interposed between the operating lever 8 and the throttle body 1, and this first return spring 19 moves the operating lever 8 in the opposite direction as indicated by the arrow 18. energize the throttle valve in the direction 20.

Between the operation lever 8 and the tenth stroke motion lever 7, the tenth stroke motion lever 7 follows the rotational movement of the operation lever 8, and a throttle valve closing direction 20 of the tenth stroke motion lever 7 is provided. A lost motion mechanism 25 is provided that can prevent the rotational movement from affecting the operating lever 8 . The lost motion mechanism 25 includes an engagement arm 21 extending to the tenth motion lever 7mQ and provided on the drum portion 8b of the operation lever 8, and a tenth motion mechanism 21 to be engaged with the engagement arm 21. The engagement arm portion 22 includes an engagement arm portion 22 provided on the action lever 7, and a tenth motion spring 23 interposed between the operation lever 8 and the tenth motion lever 7.
The relative position of 1 and 22 is the 10th motion spring 23
The spring forces are set to act in mutually engaging directions.

According to such a lost motion mechanism 25, when the operation lever 8 is rotated in the throttle valve opening direction 18 against the spring force of the first and second return springs 19, 24 by operating the accelerator pedal, the tenth Storm motion spring 23
The spring force causes the tenth motion lever 7 to rotate in the throttle valve opening direction 18, and the throttle shaft 2 to rotate in the throttle valve opening direction 18. Further, when the operating lever 8 is rotated in the throttle valve closing direction 20, the engaging arm 2
1 and 22, the tenth motion lever 7 and the throttle shaft 2 rotate in the left direction 20 to close the throttle.

The tenth motion spring 23 also has an operating lever 8.
a second return spring 2 that biases the throttle valve in the throttle valve closing direction 20;
4 is interposed.

The tenth motion spring 23 and the second return spring 24 are formed in a coil shape, and the receiver received by the tenth motion lever 7 is connected to the member 25 and the regulating plate 11.
A receiver received by the collar 12 is disposed coaxially surrounding the collar 12 with the member 26. These receivers are members 25.26
is formed of a synthetic resin into a bottomed double cylindrical shape surrounding the collar 12, the tenth motion spring 23 has both supports on the inner side between the members 25 and 26, and the second return spring 24 has both supports on the inner side between the members 25 and 26. It is arranged on the outer side between members 25,26. 1st
One end 23a of the zero stroke motion spring 23 is engaged with the engagement arm portion 22 of the tenth stroke motion lever 7, and the other end 23a
b is engaged with the engagement arm portion 21 of the operating lever 8. Further, one end 24a of the second return spring 24 is engaged with the engagement arm portion 21, and the other end 24b is fully engaged with the throttle body 1.

A bracket 26 is fixed to the throttle body 1, and the bracket 26 is provided with a cylindrical support member 26a having an axis parallel to the throttle shaft 2. The detection shaft 27 is rotatably supported by the cylindrical support member 26a. A 20th stroke motion lever 28 that is interlocked and connected to the operating lever 8 is supported on the detection shaft 27 so as to be relatively rotatable, and a detection lever 29 that can be engaged with the 20th stroke motion lever 28 is supported on the detection shaft 27. Fixed.

At one end of the detection shaft 27 protruding from the cylindrical support member 26a of the bracket 26, a small-diameter male threaded portion 27a with a substantially rectangular cross-sectional shape is coaxially provided via a stepped portion 27b. 27a passes through the detection lever 29, making relative rotation impossible. Moreover, the male threaded portion 27a protrudes from the detection lever 29 that is in contact with the stepped portion 27b.
A nut 30 is screwed onto the shaft, and by tightening the nut 30, the detection lever 29 is fixed to the detection shaft 27.

Further, the 20th motion lever 28 is connected to the bracket 2
The outer end of the cylindrical support member 26g in 6 and the detection lever 29
The cylindrical portion 28g that surrounds the detection shaft 27 has a basically disk-shaped disk portion 28b and a control lever 8. The drum portion 8b is interlocked and connected to the drum portion 8b via a connecting link 31. This connecting link 31 is designed to rotate the 20th stroke motion lever 28 in the direction in which the accelerator pedal is depressed, as indicated by an arrow 32, in response to the rotation of the operating lever 8 in the throttle valve opening direction 18. Both levers 8.28 are connected in order to rotate the 20th stroke motion lever 28 in an accelerator pedal return direction 34 opposite to the accelerator pedal depression direction 32 in response to the throttle closing leftward 20. be.

An engagement pin 33 having an axis parallel to the cylindrical support member 26a is implanted in the bracket 26.
A 20th motion spring 35 is interposed between the detecting lever 29 and the detecting lever 29 to rotationally urge the detecting lever 29, that is, the detecting shaft 27 in the return direction 34 of the accelerator pedal. The 20th strike motion spring 35 is formed into a coil shape that surrounds the cylindrical support member 26a. One end 35a of the 20th strike motion spring 35 is engaged with the detection lever 29, and the other end 35b is engaged with the engagement pin 33. engaged.

The disc portion 28b of the 20th stroke motion lever 28 is provided with an engaging portion 36, and the detection lever 29 is provided with an engaging portion 37 that can be engaged with the engaging portion 36. The relative positions of the two engaging portions 36 and 37 are determined by the spring force of the 20th stroke motion spring 35 interposed between the detection lever 29 and the engagement pin 33, that is, the spring force of the detection lever 29 is biased in the accelerator pedal return direction 34. The spring forces are set to act in mutually engaging directions.

Therefore, when the 20th stroke motion lever 28 rotates in the accelerator pedal depression direction 321 as the operating lever 8 rotates in the throttle valve opening direction 18, the detection lever 29 rotates in the accelerator pedal return direction 34, and as the operating lever 8 rotates in the throttle closing valve direction 20, the 20th stroke motion lever 28 rotates in the accelerator pedal return direction 34. The spring force of the 20 stroke motion spring 35 causes the detection lever 29 to rotate in the return direction 34 of the accelerator pedal, and the detection lever 29, that is, the detection shaft 27, rotates in response to the amount of rotation of the operation lever 8, that is, the amount of operation of the accelerator pedal. move.

Further, an accelerator pedal operation amount detector 38 is fixed to the bracket 26 so as to face the other end of the detection shaft 27, and a lever 39 fixed to the other end of the detection shaft 27 is connected to the accelerator pedal operation amount detector 38. It is connected to 38.

A cylindrical collar 41 is fitted to the base of the other end of the throttle shaft 2 protruding from the throttle body 1 so that its inner end abuts against the bearing 4 .

Furthermore, a control lever 9 is fixed to the other end of the throttle shaft 2 that protrudes from the collar 41. Further, a wave gear 43 is rotatably supported on the collar 41 via a bearing 42, and this driven gear 43 is connected to the throttle body 1.
The third return spring 44 interposed between the control lever 9 and the control lever 9 is biased to rotate in the throttle valve opening direction 18, and is moved away from the control lever 9. Further, a throttle opening detector 46 facing the other end of the throttle shaft 2 is supported and fixed to a bracket 45 fixed to the outer surface of the throttle body 1, and the control lever 9 is connected to the other end of the throttle shaft 2. A lever 47 fixed therewith is connected to a throttle opening detector 46 which is an opening detector. Therefore, the amount of rotation of the throttle shaft 2, that is, the opening degree of the throttle valve 6, which is a control valve, is detected by the throttle opening degree detector 46.

A support shaft 48 having an axis parallel to the throttle shaft 2 is supported between the throttle body 1 and the bracket 45, and four intermediate gears meshing with the driven gear 43 are mounted on this support shaft 48 via bearings 50. Rotatably supported.

Furthermore, the intermediate gear 49 is biased so as to be supported in the thrust direction by the bracket 45 by a spring 51 interposed between the intermediate gear 49 and the outer surface of the throttle body 1 to regulate its axial position.

A step motor 52 as an actuator is supported on the bracket 45, and a drive gear 54 fixed to an output shaft 53 of the step motor 52 is connected to the intermediate gear 4.
is engaged with. Therefore, the throttle shaft 2 is rotationally driven by the operation of the step motor 52 via the drive gear 54, the intermediate gear 49, the wave gear 43, and the control lever 9. By operating the step motor 52 when the throttle valve 6 is opened to the desired opening degree by operating the accelerator pedal, the throttle valve 6 is rotationally driven in the closing direction. At this time, the throttle shaft 2 rotates in the throttle closing valve direction 20 while resisting the spring force of the tenth motion spring 23 and separating the anchor arms 21 and 22 from each other, which affects the throttle wire 16. Never.

A dashpot 56 is supported and fixed to the throttle body 1 for slowing the rotational movement of the tenth stroke motion lever 7 supported on the throttle shaft 2 in the throttle valve closing direction 20.

This dashpot 56 is conventionally well-known, and includes a housing 57 having a periphery of a diaphragm 60 that partitions the inside of the housing 57 into a suction chamber 58 and an atmospheric pressure chamber 59, and a central portion of the diaphragm 60. One end of a connecting port 61 which movably passes through the housing 57 and extends outward on the atmospheric pressure chamber 59 side is connected to the connecting port 61 via a retainer 80.

A suction pipe 81 communicating with the suction chamber 58 is connected to the housing 57, and this suction pipe 81 is opened to the atmosphere via a jet 82 at its tip.

Therefore, when attempting to drive the connecting port/end 61 to read the diaphragm 60 in the direction of increasing the volume of the suction chamber 58, the jet 82 causes the connecting rod 61 to
A force acts in the opposite direction to the driving direction.

On the other hand, a support bolt 62 having an axis parallel to the throttle shaft 2 is screwed onto the outer surface of the throttle body 1, and a regulation lever 63 and a forced activation lever 64 are rotatably attached to the support bolt 62. supported. That is, between the head 62a of the support bolt 62 and the throttle body 1, in order from the head 62a side, there is a cylindrical collar 65 that surrounds the support bolt 62, and a disc that abuts the inner end of the collar 65. a cylindrical collar 67 that surrounds the support bolt 62 with its outer end in contact with the regulation plate 66, and a regulation plate 68 that is interposed between the inner end of the collar 67 and the throttle body 1. are fitted in this order, and by tightening the support bolt 62, the collar 65, regulation plate 66, collar 67, and regulation plate 68 are fixed to the support bolt 62. The regulation lever 63 has a collar 65 between the head 62a of the support bolt 62 and the regulation plate 66°.
It is supported so that it can rotate, and the forced activation lever 64
is rotatably supported by a collar 67 between regulating plates 66 and 68.

The regulation lever 63 includes an adjustment screw 6 whose tip can come into contact with a contact arm 70 provided on the tenth motion lever 7.
The adjustment screw 69 and the contact arm 70 are screwed together so that the forward and backward positions thereof can be adjusted. They are set to abut each other accordingly. Also slot/
An adjustment screw 71 is screwed into the nottle body 1 so as to be able to adjust forward and backward positions when the tenth stroke motion lever 7 rotates to the position where the throttle valve 6 is fully opened. .

The other end of the connecting rod 61 in the dashpot 56 is connected to the regulating lever 63, and the connecting state of the connecting rod 61 is as follows when the adjusting screw 69 is in contact with the abutting arm 70. -7 is rotated in the throttle valve closing direction 20, the diaphragm 60 to which the connecting rod 61 is connected is bent to increase the volume of the suction chamber 58.

The forced activation lever 64 is provided with an abutment arm 72, and an adjustment screw 73 whose tip can be brought into contact with the abutment arm 72 is screwed into the regulation lever 63 so that its forward and backward positions can be adjusted. The relative positions of the abutment arm 72 and the adjustment screw 73 are determined in the direction in which the abutment arm 72 abuts the adjustment screw 73 due to the spring force of the spring 74 interposed between the throttle body 1 and the forced activation lever 64. It is set to be energized by This spring 74 has a spring force that urges the tenth stroke motion lever 7 in the throttle valve opening direction 18 via the restriction lever 63 which is in contact with the forced activation lever 64 by the contact arm portion 72 and the adjustment screw 73. When the operating lever 8 rotates in the throttle valve opening direction 18 from the fully closed position of the throttle valve 6, the regulation lever 63 and the forced activation lever 64 follow and rotate due to the spring 74. When the retainer 80 of the dashpot 56 comes into contact with the inner surface of the housing 57 on the suction chamber 58 side, the adjustment screw 69
Then, the contact state of the contact arm portion 70 is released.

In FIG. 5, an operating lever 8 and a forced activation lever 6 are shown.
Between 4 and 4, when the operation lever 8 located at the position corresponding to the fully open position of the throttle valve 6 is rotated in the throttle valve opening direction 18, the forced activation lever 64 is forcibly rotated, and the regulation lever 63 is rotated. A forced activation mechanism 75 is provided for forcibly rotating the tenth motion lever 7, that is, the throttle shaft 2, in the throttle valve opening direction 18 via the throttle valve opening mechanism 75.

The forced activation mechanism 75 has a pressure receiving surface 76 provided on the side surface of the forced activation lever 64, and is pivotally supported by the operating lever 8 with an axis parallel to the throttle shaft 2 so as to roll along the pressure receiving surface 76. It is removed from roller 77. In addition, the pressure receiving surface 76 and the roller 77 are in contact with each other between the position of the operating lever 8 corresponding to the fully closed position of the throttle valve 6 and the position where the operating lever 8 is slightly rotated in the throttle valve opening direction 18 from that state. The pressure receiving surface 76 rotates the forced activation lever 64 in the throttle valve opening direction 18 by a roller 77 in response to the rotation of the operating lever 8 in the throttle valve opening direction 18 from the fully open position. Formed as expected.

Next, the operation of the throttle control device shown in FIGS. 1 to 5 will be explained.

When the operating lever 8 is rotated in the throttle valve opening direction 18 by operating the accelerator pedal while the step motor 52 is fully open and stopped, the engagement arms 21, 22
Due to the engagement, the tenth motion lever 7, that is, the throttle shaft 2, is rotated in the throttle valve opening direction 18,
The throttle valve 6 is rotated in the throttle valve opening direction 18 to a desired opening degree.

At this time, the step motor 52 is in a freely rotatable state, and in response to the rotational movement of the throttle valve 6 in the opening direction,
Rotational power is also transmitted to the step motor 52 via the control lever 9 and the gears 43, 48.degree. 53, so that the step motor 52 rotates freely.

The rotational movement of the operating lever 8 in response to the accelerator pedal operation is also transmitted to the 20th stroke motion lever 28 via the connecting link 31, and the two detection levers are activated by the engagement of the engaging portions 36 and 37. That is, the detection shaft 27 rotates in the accelerator pedal depression direction 32. Therefore, the rotation amount of the throttle shaft 2, that is, the throttle opening degree can be detected by the throttle opening degree detector 46, and the rotation amount of the operating lever 8, that is, the accelerator pedal operation amount can be detected by the accelerator pedal operation amount detector 38.

By the way, at the initial stage of rotating the throttle valve 6 from its fully open position in the throttle valve opening direction 18,
If only the operating lever 8 and the tenth motion lever 7 are interlocked and connected via the lost motion mechanism 25, the starting force of the throttle shaft 2 will be insufficient, and the initial rotational movement of the throttle shaft 2 will not be smooth. There are cases. However, due to the action of the forced start mechanism 75, the rethrottle shaft 2
The initial rotational movement is forcibly performed. That is, when the operating lever 8 rotates to rotate the throttle valve 6 from its fully closed position, the lost motion lever 7 contacts the pressure receiving surface 76 and rolls, thereby rotationally driving the forced activation lever 64. The rotation of the forced activation lever 64 is caused by the contact arm 7
2 through the adjustment screw 73.
The force is further transmitted to the tenth motion lever 7, which has an abutting arm portion 70 that abuts the adjustment screw 69 of the regulating lever 63. Therefore, when the operation lever 7 is initially rotated, the tenth stroke motion lever 7 is forcibly rotated, and the throttle shaft 2, that is, the throttle valve 6 is forcibly rotated.
The initial rotation movement from the fully closed position becomes smooth.

Further, when the throttle valve 6 is rotated by the operation lever 8 to the opening degree, the throttle shaft 2, that is, the throttle valve 6 is provided with the first, second, and third return springs 19, 24, .
A spring force of 44 is acting on the closing side. Therefore, by relaxing the pulling force of the throttle wire 16, the operating lever 8 rotates in the throttle valve closing direction 20, and the throttle shaft 2 and the throttle valve 6 also rotate in the closing direction.

At this time, when the throttle valve 6 rotates to the vicinity of its fully closed position, the retainer 80 in the dashbot 56 moves into the suction chamber 5.
After the adjustment screw 69 of the forced activation lever 64 comes into contact with the contact arm 70 due to the state in which the 8 side contacts the housing 57, the dashbot 56 due to the increase in the volume of the suction chamber 58
The damping force acts on the tenth motion lever 7, which acts on the throttle shaft 2 and the lost motion lever 7, and the rotational speed of the throttle shaft 2 and the throttle valve 6 toward the closing side is moderately suppressed.

Further, when the operating lever 8 is rotated in the throttle valve closing direction 20, the lever 3 is detected by the accelerator pedal operating amount detector 38.
Let us assume a case where the detection shaft 27 connected through the two does not rotate smoothly due to a malfunction of the accelerator pedal operation amount detector 38 or the like.

In this case, the operating lever 8 rotates the 20th stroke motion lever 28 in the accelerator pedal return direction 34 while resisting the spring force of the 20th stroke motion spring 35 and separating the engaging portions 36 and 37. This allows the throttle valve 6 to be reliably rotated to the closing side.

As described above, when the throttle valve 6 is opened to a certain opening degree by operating the accelerator pedal, and the throttle valve 6 is driven to the closing side for traction control during starting and acceleration, etc., the step motor 52 is operated. Activate it. Due to the operation of the step motor 52, the throttle shaft 2 and the throttle valve 6 are moved by the tenth stroke motion spring 23 so that the engaging portion 21 of the operating lever 8 and the engaging portion 22 of the tenth stroke lever 7 are separated. It can be rotated against the spring force, and the throttle valve 6 can be driven in the closing direction regardless of the operation of the accelerator pedal.

The throttle control device for an automobile shown in FIGS. 1 to 5 has been described above as an example of an object to which the method of the present invention is applied.

Next, an embodiment of the present invention applied to control of the throttle valve 6, which is the control valve of this throttle control device, will be described based on FIGS. 6 to 8.

Note that this example is a hook adopted as a part of the above-mentioned traction control etc.

FIG. 6 is a block diagram showing an example of a device used in the method of the present invention, FIG. 7 is a time chart showing interrupt timing, and FIG. 8 is a flow chart showing an interrupt processing program.

In FIG. 6, 100, 101, 102 and 103
are phase coils of the step motor 52 that drives the throttle valve 6. Further, 104 is a microcomputer, 105, 106, 107 and 108 are amplifiers respectively connected to the output ports of the microcomputer 104, 109, 110, 111 and 112 are resistors, 113, 114, 115 and 116 are transistors,
Diodes 117, 118, 119 and 120 are connected as shown in FIG. Therefore, depending on the value of the output port of the microcomputer 104, each transistor 113 to 116 is turned ON/OFF.
The FF states are determined, and in turn, the excitation states of the coils 100 to 103 of each phase of the step motor 52 are determined.

Further, in FIG. 6, reference numeral 46 denotes a throttle opening degree detector, which is the same as that shown in FIGS. 1 to 5 above, and is therefore given the same reference numeral. 121 is an A/D converter for A/D converting the detection signal of the throttle opening degree detector 46;
The D converter starts A/D conversion upon receiving the start signal supplied from the microcomputer 104, and when the conversion is completed, supplies the end signal and the A/D conversion value to the microcomputer 104. ing.

Note that when the A/D conversion is completed, the A/D converter 121 latches the A/D conversion value in the output section, and holds it until the next A/D conversion is completed upon receiving the next start signal. It has become so.

The microcomputer 104 includes an oscillation circuit and a pulse distribution circuit therein, and sends pulse signals to the coils 100 to 103 of each phase of the step motor 52.

For example, when driving the step motor 52 with one-phase excitation, pulse signals are sent to the coil 100, the coil 101, the coil 102, and the coil 103 in this order. The pulse train output from the oscillation circuit is, for example, T, as shown in FIG. 7(a). Pulses are formed at intervals.

These pulses are routed to the desired coil by a circuit. In the example shown in FIG. 7(a), the period is T. However, the period may be changed as necessary. Also, the period To
Since this determines the pulse rate of the step motor 52, it is determined in consideration of the performance of the step motor 52, and is also determined to be a short time in order to improve responsiveness. motor 52
If the pulse rate of is 600 pps, the time period is T. becomes 1.67m5. Further, in the case of the embodiment shown in the drawings, the step motor 52 has a pulse rate of 300±50 pps.
Resonance occurs when , and the resonance time Tl is 3.33±0.02
m5, and Tox2-T between To and Tl.
There is a relationship of l.

In this embodiment, it is assumed that the A/D is used as part of traction control, so although it is not shown in the drawings, for example, an idle wheel speed detector, a driving wheel speed detector, etc. The microcomputer 9104 is connected via a converter, and based on the detected data, the microcomputer 104 determines whether or not to perform traction control.

In this case, the target opening data of the throttle valve 6 is calculated by calculation, and when performing traxigin control etc., the pulses shown in FIG. 7(a) are sent from the microcomputer 104 at predetermined time intervals. It is output toward the phase coils 100 to 103.

When the pulse train shown in FIG. 7(a) is input, the microcomputer 103
The process shown in FIG. 8 is executed.

That is, when there is a pulse input shown in FIG. 7(a), interrupt processing is started in step 130, and step 131 is started.
It is determined whether the contents of the A register are 2 or not. Step 1
In step 32, as will be seen from the description below, it is determined whether the interrupt in question is an interrupt occurring within two cycles from when the output port value was switched to a different value immediately before. . That is, in this example, ToX2-
Since there is a relationship of T1, in step 131, the elapsed time from when the output port value was switched to a different value immediately before the interrupt is monitored, and it is determined whether the elapsed time matches the resonance time T1. You are deciding whether or not to do so. Then, when it is determined in step 131 that it is A-2, that is, when it is determined that it matches the resonance time T1, the value obtained by adding 1 to the original content of the A register in step 139 is set as the content of the A register. At the same time, excitation switching of the coil is stopped. Next, in step 138, the interrupt processing is ended, and the process returns to the main routine to start other processing. On the other hand, when it is determined in step 131 that the time is not A or 2, that is, when it is determined that it does not match the resonance time T1, the process moves to step 132. In step 132, a start signal is sent to the A/D converter 121 to
The D converter 121 performs A/D conversion, and the A/D converter 121
After receiving an end signal from the controller, the A/D converted value is read as detected opening data. Next, in step 133, the detected opening degree data and the target opening degree data are compared and calculated. Then, in step 134, the output port value is switched to a value according to the calculation result. Therefore, at step 134, if the detected opening does not match the target opening, the step motor 52 starts moving one step in the matching direction (throttle valve closing direction in traction control, etc.). If so, the step motor 52 will maintain that position. Then, when step 134 ends, the process moves to step 135.

In step 135, it is determined whether the output port value has been switched to a different value by the process in step 134. If it is determined that the value has been switched to a different value, the contents of the A° register are set to 1 in step 136, and the process is performed in step 13.
Ends at 8. On the other hand, if it is determined in step 135 that the value has not been changed to a different value, in step 137 the original contents of the A register are added to 1 and the value is set as the contents of the A register, and the process ends in step 138.

As can be seen from the above explanation, while the traction control etc. are being performed, the process shown in FIG. 8 is performed every time the pulse input shown in FIG. The method is executed, and the throttle valve 6 is controlled to the target opening degree required for traction control etc., and the actual switching interval of the phase excitation of the step motor 52 does not coincide with the resonance time. Resonance of the step motor 52 is always avoided, step-out, etc. are prevented, and stable control is realized.

Next, an example of the operation of the throttle valve 6 in the case of the above-mentioned embodiment is shown in FIG. 7(b), so this will be explained. The vertical axis in FIG. 7(b) indicates the opening degree of the throttle valve 6. Note that in FIG. 7(b), the processing time of the interrupt processing shown in FIG. 8 is ignored.

First, before the interrupt 11 occurs, the throttle valve 6
The actual opening degree is θ1, and the target opening degree according to the target opening degree data is θ2 from before the interruption at t 1 to a time point between t 1 and t5 and t4. Therefore, tl.

The phase excitation state of the step motor 52 is switched at each interrupt of tz and ta, and the opening degree of the throttle valve 6 approaches the target opening degree θ with each step.
After t, the opening degree is brought to match the target opening θ2. When the interrupt at t4 occurs, the target opening data has not yet been changed and the target opening is θ2, so the phase excitation state of the step motor 52 is not switched at the interrupt at t4, and the throttle valve 6 is not switched. The opening degree remains at θ2.

Assuming that the target opening degree data is changed between t4 and t5 and the target opening degree is changed to 03,
If 131°139.135,136 in the above figure 8
, 137, the opening degree of the throttle valve 6 would change as shown by the imaginary line. In that case, the switching interval t3 to t5 of the phase excitation state of the step motor 52 will coincide with the resonance time T1, resonance will occur, and tax adjustment etc. will occur. However, in the above-described embodiment of the present invention, if the elapsed time from ta, which is the time of the previous switching, coincides with the resonance time T1, the switching is aborted, so at the interrupt at t5, the output vote value is is not switched and the phase excitation state is not switched, and the opening degree of the throttle valve 6 changes as shown by the solid line in FIG. 7(b), and the opening degree of the throttle valve 6 reaches the target opening degree θ after t7.
3.

In addition, in the embodiment described above, by determining how many cycles the interrupt has occurred since the time when the output vote value was changed to a different value immediately before, the output vote value is changed immediately before. The present invention uses an internal timer or an external timer to monitor the elapsed time from the time the interrupt period T is switched. The elapsed time may be directly monitored regardless of the In this case, even if another interrupt with a higher priority occurs during the interrupt processing shown in FIG. 8, resonance can be reliably avoided.

[Effects of the Invention] The present invention has the effect of improving responsiveness, always avoiding resonance of the step motor to prevent step-out, etc., and enabling stable control.

[Brief explanation of drawings]

1 to 5 show a throttle control device for an automobile having a throttle valve, which is an example of the controlled object of the present invention. FIG. 1 is a front view, and FIG. figure,
Figure 3 is a sectional view taken along the line ■-■ in Figure 2, and Figure 4 is a cross-sectional view taken along the line ■ in Figure 2.
The arrow diagram and FIG. 5 are cross-sectional views taken along the line v-V in FIG. 3. Also,
Fig. 6 is an electric circuit diagram showing an example of the device used in the present invention, Fig. 7(a) is a time chart showing interrupt timing, Fig. 7(b) is an operation explanatory diagram, and Fig. 8 is interrupt processing. 2 is a flowchart showing a program. 6... Throttle valve as a control valve, 46... Throttle opening detector as an opening detector, 52... Step motor, 104... Microcomputer, 121...
A/D converter.

Claims (1)

[Claims] Using a step motor that drives a control valve of an automobile, and a microcomputer that determines the excitation state of the step motor according to an output port value, an interrupt is periodically applied to the microcomputer, and each interrupt causes the microcomputer to A method for controlling a control valve of an automobile to a target opening degree, wherein the detected opening degree data and the target opening degree data of the control valve are compared and calculated, and the output port value is switched to a value according to the result, For each of the above interrupts, the elapsed time from when the above output port value was switched to a different value immediately before the above interrupt is monitored, and if the elapsed time matches the resonance time of the above step motor, the above output port value is A method for controlling an automobile control valve to a target opening degree, the method comprising stopping value switching.