JPH0361653A - How to control an in-vehicle engine - Google Patents

Abstract

PURPOSE:To improve the processing efficiency of a microcomputer by starting the A/D conversion of the opening degree detection signal of a control valve in each interruption in the control for a step motor and reading the A/D conversion value in the preceding time as the detected opening degree data into the microcomputer. CONSTITUTION:In the traction control, a microcomputer 104 starts interruption control, and outputs a pulse train into the transistors 113-116 for drive in succession, and a pulse electric current is supplied into each phase coil 100-103 of a step motor, and a throttle valve is driven in the closing direction. In this case, in each interruption for selecting the phase excitation, the microcomputer 104 outputs a start signal into an A/D converter 121, and the A/D conversion of the throttle opening degree which is detected by a detector 46 is started, and the A/D conversion value in the preceding time is read as the detected opening degree data, and the aimed opening degree is calculated, and the pulse train is outputted. The A/D conversion value is memorized by the A/D conversion completion signal. Thus, the utilization efficiency of the microcomputer can be improved.

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a control valve that controls the operating state of an on-vehicle engine;
For example, it relates to a method of controlling a throttle valve to a target opening degree, and can be employed, for example, in so-called traction control, auto cruising control, and the like. [Conventional technology] Traction control, auto cruising control, etc. have traditionally been used in automobiles.
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 at each interrupt, and the excitation state of the step motor is switched. As a result, the control valve is driven by the step motor and is controlled to the target opening degree. However, when using this method, the problem is how to read the detected opening data into the microcomputer. That is, in the case of this method, for each interrupt, the A/D converter that converts the detection signal of the opening degree detector that detects the opening degree of the control valve into A/D converts the detection signal of the opening degree detector that detects the opening degree of the control valve.
Start /D conversion, wait for a completion signal from the A/D converter indicating that the A/D conversion has been completed, and after receiving the completion signal, continue the A/D conversion value as the detected opening data. It is conceivable to perform the above comparison calculation and switch the output port value based on the detected opening degree data, but it is necessary to convert the signal values of a large number of analog sensors using an A/D converter. If we decide to make the microcomputer wait for that amount of time, the processing time due to the above-mentioned interrupts will become longer, the microcomputer usage efficiency will deteriorate, other interrupts, etc. will be restricted, and other interrupts using the microcomputer will be This may cause problems with control (for example, ignition timing control, etc.). [Problems to be Solved by the Invention] The present invention has been made in view of the above circumstances, and is an in-vehicle device that improves the usage efficiency of a microcomputer and does not pose a risk of interfering with other controls using the microcomputer. The purpose is to provide a method for controlling an engine. [Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention provides a step motor that drives a control valve that controls the operating state of an in-vehicle engine, and a step motor that drives a control valve that controls the operating state of an in-vehicle engine, and Using a microcomputer that determines the excitation state of the step motor, an interrupt is sent to the microcomputer in synchronization with the switching of the output port value, and for each interrupt, the detected opening data of the control valve is sent to the microcomputer. A comparison calculation is made with the target opening degree data, and the output port value is switched to a value according to the result. Then, for each of the above interrupts, the A/D converter that converts the detection signal of the opening degree detector that detects the opening degree of the control valve to A/D starts the A/D conversion. Then, the A/D converter starts A/D conversion and the previous A/D conversion value obtained is read into the microcomputer as the detected opening degree data.

[Effect]

According to the present invention, there is no need to wait for the completion of A/D conversion in the above interrupt, so the processing time due to the above interrupt is reduced by starting A/D conversion in the interrupt as described above and then waiting until the completion of the A/D conversion. Compared to the previous case, the time required for conversion can be reduced. Therefore, the shortened time can be used for other processing, so the efficiency of using the microcomputer can be improved, and other controls using the microcomputer will not be affected. [Embodiment] Hereinafter, 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 an automobile throttle control device shown in FIGS. 1 to 5, will be described. First, Figures 1 to 5r! The throttle control device for an automobile shown in gJ will be explained. This throttle control device is 1. An operating lever 8, which is linked to the operation of an accelerator pedal, is mounted relative to a throttle shaft 2 which has a butterfly-type throttle valve 6, is rotatably supported on a support body 1, and is biased by a spring in the closing direction of the throttle valve 6. A control lever 9 that is rotatably supported and interlocked and connected to a step motor 52 serving as an actuator is connected to the operating lever 8 and the operating lever 8.
The operation lever 8 is rotated in the direction of closing the throttle valve.
A lost motion spring is interposed between the lost motion lever 7, which is fixed to the throttle shaft 2 to be engaged with the lost motion lever 7, and which exerts a spring force in a direction to engage 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 about an axis parallel to the throttle shaft 2, and the regulation lever 63 and the lost motion lever 7 are arranged so that the throttle valve 6 is in a low opening range. 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, and the regulation lever 63 has a damping force applied to the rotation in the one direction. A dash board 56 is connected thereto. 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 of the resin bearing made of a composite resin which abuts against the outer surface of the throttle body 1 is regulated by a member 15 and a regulating plate 11. 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 coiled 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. Close the throttle in the direction 20 to the left. 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 the throttle valve closing direction of the tenth stroke motion lever 7 is provided. A lost motion mechanism 25 is provided that can prevent the rotational movement toward 20 from affecting the operating lever 8 . This lost motion mechanism 25 includes a retaining arm portion 2 that extends toward the tenth motion lever 7 and is provided on the drum portion 8b of the operating lever 8.
1, an engagement arm 22 provided on the tenth strike motion lever 7 to engage with the engagement arm 21, and an operating lever 8.
and a tenth force motion spring 23 interposed between the tenth force motion lever 7, and the engaging arm portion 21,
The relative positions of the springs 22 are set so that the spring forces of the tenth motion springs 23 act in the direction of mutual engagement. 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
1.22 engagement causes the tenth stroke motion lever 7 and the throttle shaft 2 to rotate in the throttle closing valve direction 20. 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 disposed on the outer side between members 25 and 26. 1st
One end 23a of the zero stroke motion spring 23 is engaged with the engagement arm 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 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 which is interlocked and connected to the operating lever 8 is supported on the detection shaft 27 so as to be relatively rotatable, and a T520 stroke motion lever 28
Two detection levers that can be engaged with are 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
6 and the outer end of the cylindrical support member 26a and the detection lever 29
A cylindrical portion 28a surrounding the detection shaft 27 has a basically disk-shaped disk portion 28b and an operating lever 8. and the drum portion 8b (via the connecting link 31) are interlocked and connected to each other. This connecting link 31 is designed to prevent the 20th stroke motion: /L//<-28 from rotating in the accelerator pedal depression direction 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 are moved simultaneously to move the 20th stroke motion lever 28 in the return direction 34 of the accelerator pedal, which is opposite to the depression direction 32 of the accelerator pedal, in response to the operation lever 8 being moved in the throttle closing valve direction 20.
．． 28. An engagement pin 33 having an axis parallel to the cylindrical support member 26a is implanted in the bracket 26, and the engagement pin 33
The detection lever 29, that is, the detection II! is located between the detection lever 29 and the detection lever 29. A 20th motion spring 35 is interposed to rotationally bias the accelerator pedal 127 in the return direction 34 of the accelerator pedal. The 20th motion spring 35 is connected to the cylindrical support member 2
It is formed in a coil shape surrounding 6a, and this 20th
One end 35a of the motion spring 35 is connected to the detection lever 29.
The other end 35b is engaged with the engagement pin 33. The disk portion 28b of the 20th stroke motion lever 28 is provided with an engaging portion 36, and the two detection levers are provided with engaging portions 37 that can be engaged with the retaining portion 36. The relative position of the two image matching parts 36 and 37 is 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 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 32 as the operating lever 8 rotates in the throttle valve opening direction 18, the engaging portion 3
6 and 37, 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. When the detection lever 29 rotates in the return direction 34 of the accelerator pedal, the spring force of the 20th stroke motion spring 35 causes the detection lever 29 to rotate in the return direction 34 of the accelerator pedal, corresponding to the amount of rotation of the operating lever 8, that is, the amount of operation of the accelerator pedal. As a result, the two detection levers, that is, the detection shaft 27, rotate. 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 driven gear 43 is rotatably supported on the collar 41 via a bearing 42, and this driven gear 43 is attached 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 four intermediate gears are energized so as to be supported in the thrust direction by the bracket 45 by a spring 51 interposed between the outer surface of the throttle body 1 and the outer surface of the throttle body 1 to regulate their axial positions. 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 operation of the step motor 52 rotationally drives the throttle shaft 2 via the drive gear 54, the intermediate gear 49, the driven 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 engaging arms 21 and 22 from each other, which affects the throttle wire 16. Never. A dashbot 56 is supported and fixed to the throttle body 1 to slow down 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 peripheral portion of a diaphragm 60 that partitions the inside of the housing 57 into a suction chamber 58 and an atmospheric pressure chamber 59. One end of a connecting rod 61 that movably passes through the housing 57 on the atmospheric pressure chamber 59 side and extends outward is connected via a retainer 80. A suction pipe 81 communicating with the suction chamber 58 is connected to the housing 57, and this suction pipe 8 is opened to the atmosphere through a jet 82 at its tip. Therefore, when an attempt is made to drive the connecting rod 61 to cause the diaphragm 60 to read in a direction that increases the volume of the suction chamber 58, a force in the opposite direction to the driving direction is applied to the connecting rod 61 due to the action of the jet 82. Become. 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 is rotatably supported by a collar 65 between the head 62a of the support bolt 62 and the regulation plate 66, and the forced activation lever 64 is rotatably supported by the collar 671 between the regulation plates 66 and 68. supported. 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.
9 are screwed together so that the forward and backward positions can be adjusted, and the relative position of the adjustment screw 69 and the contact arm 70 is determined according to the rotation of the tenth stroke motion lever 7 in the throttle closing valve direction 20. are set to abut each other. Further, in the throttle body 1, there is an adjustment screw 71 that is connected to the abutment arm 70 when the tenth stroke motion lever 7 rotates to the position where the throttle valve 6 is fully closed. possible and screwed together. The other end of the connecting rod 61 in the dash bot 56 is connected to the regulating lever 63, and the connecting state of the connecting rod 61 is such that when the adjusting screw 69 is in contact with the abutting arm 70, the tenth motion lever 7 The diaphragm 60 to which the connecting rod 61 is connected is bent to increase the volume of the suction chamber 58 when the valve is rotated in the throttle valve closing direction 20 . 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 dashbot 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 includes a pressure receiving surface 76 provided on the side surface of the forced activation lever 64, and a roller that is pivoted on the operating lever 8 and has an axis parallel to the throttle shaft 2 so as to move along the pressure receiving surface 76. It consists of 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 position. 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 arm 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 engagement of the engaging portions 36 and 37 causes the detection lever 29, i.e. 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 closed 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 activation mechanism 75, the initial rotational movement of the throttle shaft 2 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 72.
The force is transmitted to the regulating lever 63 in contact via the adjusting screw 73, and is further transmitted to the tenth motion lever 7, which has an abutting arm portion 70 in contact with the adjusting screw 69 of the regulating lever 63. Therefore, during the initial rotation of the operating lever 7, the tenth stroke lever 7 is forcibly rotated, and the initial rotation of the throttle shaft 2, that is, the throttle valve 6, 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 dashpot 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.
A case will be assumed in which the detection shaft 27 connected via the accelerator pedal 9 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 embodiment is an example 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. xo2 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
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 value of the output port of the microcomputer-04 is switched every cycle T according to the pulse rate at which the step motor 52 is driven. This switching period T 1 varies depending on the pulse rate (pps) at which the step motor 52 is driven. For example, if the pulse rate of the step motor 52 is set to 600 p.
ps, the period To is 1.67m5
(-1 second ÷ 600 pps). The microcomputer-04 is configured to receive an interrupt every cycle T in synchronization with the switching timing of its output port value, and at the same time as this interrupt, the interrupt subroutine shown in Figure 8 is executed. It is now possible to do so. In addition, in this experiment, it is assumed that they will be used as part of traction control, etc., so although they are not shown in the drawings, for example, non-driving wheel speed detectors, driving wheel speed detectors, etc. It is connected to the microcomputer-04 via a D converter, and based on these detection data, the microcomputer-04 determines whether or not to perform traction control. The target opening data of the throttle valve 6 is calculated by calculation, and the above-mentioned interrupt is permitted only when performing traction control, etc., and when not performing traction control, etc., the interrupt is not permitted and the microcomputer The output port 104 is reset and the coils 100 to 103 of any phase of the step motor 52 are not excited, so that the step motor 52 can freely rotate as described above. Then, when the interrupt shown in FIG. 7 is permitted at every predetermined period T, the microcomputer 03 is caused to execute the process shown in FIG. 8 for each interrupt. That is, when an interrupt occurs at the period T shown in FIG. Read as degree data. The A/D conversion value latched in the output section of the A/D converter 121 at this point is the A/D conversion value obtained by starting the A/D conversion in step 132 due to the previous interrupt (previously by To). It is a value. Note that the period T shown in FIG. 7 above. Since the time required for A/D conversion is longer than the time required for A/D conversion, by the time the current interrupt occurs, the A/D conversion time due to the previous interrupt has already been completed.
/D conversion has finished. Next, in step 132, A
An A/D conversion start signal is output to the A/D converter 121. Next, without waiting for the completion of A/D conversion by this A/D converter 121, the A/D conversion value (detected opening data) read in step 131 is compared with the target opening data. (Step 133). Then, the output port value corresponding to the calculation result is stored in the buffer (step 134). Then, when the output port value is switched next time, the output port value stored in this buffer is output from the output port. As a result, if the detected opening does not match the target opening, the step motor 52 moves in the matching direction by 1 step each time the output port value is switched.
The step motor 52 rotates step by step, and if they match, the step motor 52 maintains its position. When the above-mentioned processing is completed, the process returns to the main routine and starts other processing. As can be seen from the above explanation, while traction control etc. are being performed, the process shown in FIG. 8 is performed every cycle T shown in FIG. will be executed, and the throttle valve 6
is controlled to the target opening required by traction control, etc. In the method of the present invention described above, there is no need to wait from the start of A/D conversion to its end, so the processing time is
Compared to the case of waiting until the A/D conversion is completed, the time required for the conversion can be reduced. Therefore, the shortened time can be used for other processing, so the efficiency of using the microcomputer 104 can be improved, and other controls such as ignition timing control using the microcomputer 104 are also prevented. It never happens. In addition, in the present invention described above, 131.1 in FIG.
As can be seen from 33, the A/D obtained by A/D conversion by the A/D converter 121 in the previous interrupt shown in FIG. 7 above.
Since the converted value is used for the comparison calculation in the current interrupt shown in the seventh diagram, the current operation of the step motor 52 is determined based on the detected opening data in the past by To, and the control operation is adjusted accordingly. You will be late. However, the delay can be ignored in practice. That is,
When the throttle valve 6 is moved at high speed, it may close by 80'' at 0 and IS, but even in this case, the period TO-
The throttle valve moves during 1,67m5 is approximately 1.3
6, and this degree can be sufficiently ignored in practical terms. [Effects of the Invention] The present invention can shorten interrupt processing time,
The efficiency of using the microcomputer can be improved, and other controls using the microcomputer are not hindered.

[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 gap in FIG. 5 is a sectional view taken along the line v-vtI in FIG. 3. Further, FIG. 6 is an electric circuit diagram showing an example of a device used in the present invention, FIG. 7 is a time chart showing interrupt timing, and FIG. 8 is a flow chart showing an interrupt processing program. 6... Throttle valve as a control valve, 46... Throttle opening detector as an opening detector, 52... Pulse motor, O4... Microcomputer, 1... A/D converter.

Claims (1)

[Claims] A step motor that drives a control valve that controls the operating state of an in-vehicle engine, and a microcomputer that determines the excitation state of the step motor according to periodically switched output port values are used. Interrupts synchronized with value switching, and for each interrupt, the above microcomputer is
A method for controlling an in-vehicle engine by comparing detected opening data and target opening data of the control valve and switching the output port value to a value according to the result, the method comprising: While causing the A/D converter to A/D convert the detection signal of the opening detector that detects the opening of the control valve to start the A/D conversion, the A/D converter A method for controlling an on-vehicle engine, characterized in that a previous A/D conversion value obtained by starting A/D conversion is read into the microcomputer as the detected opening data.