JPS6296757A - Controller for opening and closing of throttle valve - Google Patents

Abstract

PURPOSE:To automatically return a device to a normal state to improve its safety by stopping the output of a driving signal delivered to a step motor for opening and closing a throttle valve, and by synchronously initializing a step position memory, when an abnormality detecting means has detected the abnormal state of the device. CONSTITUTION:The above mentioned device controls a step motor M2 by a driving means M8 on the basis of deviation between the target step position of the step motor M2 which is computed by a computing means M7 according to an output from a detecting means for the state of engine operation M6 and a step position read into a memory M3. An abnormality detecting means 10 detects the abnormal state of a device using an output from the means of detecting throttle opening M9 as one parameter. In this case, when abnormality detecting means 10 has detected the abnormal state of the device, a stopping means M13 temporarily stops the function of a driving means M8, and at the same time, an initializing means m14 initializes the memory M3, and a throttle valve m1 is thereby pushed into a closing direction by a pushing means M11.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a throttle valve opening/closing control device that uses a step motor to control the opening and closing of a throttle valve, and more particularly, to a throttle valve opening/closing control device that uses a step motor to control the opening and closing of a throttle valve. The present invention relates to a throttle valve opening/closing control device equipped with an abnormality detection device for detecting.

[Prior Art] Conventionally, in order to precisely control the intake air amount of an internal combustion engine according to its operating condition, a so-called so-called method has been used in which a step motor is used to electrically control the opening and closing of a throttle valve provided in the intake system of an internal combustion engine. Linkless throttle devices are known. In addition, in this type of device, if some abnormality occurs in the control system, such as when the step motor loses synchronization, and the opening of the throttle valve cannot be controlled satisfactorily,
Since the intake air amount cannot be controlled according to the operating state of the engine and drivability is impaired, a throttle opening sensor is used as described in, for example, Japanese Patent Laid-Open No. 59-119036 or Japanese Patent Laid-Open No. 59-190441. The deviation between the throttle opening detected using the step motor and the throttle opening estimated from the drive signal output to the step motor is determined, and when the deviation exceeds a predetermined value, an abnormality in the device is detected. Equipped with a detection device is being considered.

[Problems to be Solved by the Invention] However, although the above-mentioned conventional device can detect an abnormality in the device, it is difficult to restore the device to a normal state and continue operating the device after detecting the abnormality. I couldn't. In other words, if an abnormality occurs in the device, such as when the step motor goes out of step, it is possible to detect the abnormality and give a warning to the driver, etc., but it is not possible to restore the abnormality to the normal state by itself. The driver was unable to do so, and the driver had to perform operations to restore normal operation, such as stopping and restarting the engine.

Therefore, the present invention provides a throttle system that can automatically return the device to a normal state and continue operating the device when at least a temporary electrical failure occurs in the device, such as a step motor stepping out. This device was developed for the purpose of providing a valve opening/closing control device, and had the following configuration.

[Means for Solving the Problems] That is, the configuration of the present invention as a means for solving the above problems includes, as shown in FIG. 1, a step motor M2 that opens and closes a throttle valve M1; Step position initializing means M3 that stores the step position of motor M2; Operating state detecting means M6 that detects the operating state of internal combustion engine M5 including at least the amount of depression of accelerator pedal M4; and the detection result of said operating state detecting means M6. Target step position calculation means M7 calculates a target step position of the step motor M2 according to the step position, and compares the calculated target step position with the step position stored in the step position initialization means M3, step motor drive means M8 for outputting a drive signal to the step motor M2 so that the position becomes the target step position, and for updating the step position stored in the step position initialization means M3 in accordance with the drive signal; Throttle opening detection means M9 that detects the opening of the throttle valve M1; and abnormality detection means M that detects an abnormality in the device using the detection result of the throttle opening detection means M9 as one parameter.
10, a throttle valve opening/closing control device comprising: urging means M11 for urging the throttle valve M1 in the closing direction; and a stopper M12 for restricting movement of the throttle valve M1 in the closing direction to a fully open position. , the above abnormality detection means MI
a drive signal output stop means M13 that temporarily stops the output of the drive signal from the step motor drive means M8 when an abnormality of the device is detected at O; and the drive signal stop means M13 stops the output of the drive signal. At the same time, step position initializing means M initializes the step position stored in the step position initializing means M3.
14, and an opening/closing control device for a throttle valve.

Here, the operating state detecting means M6 is for detecting the operating state of the internal combustion engine M5 necessary when the target step position calculating means M7 determines the target step position of the throttle valve M1, and is used to detect at least the operating state of the internal combustion engine M5. It is equipped with an accelerator position sensor that detects the amount of depression. In addition to the above-mentioned accelerator position sensor, the operating state detecting means M5 may include various sensors for detecting the engine speed, cooling water temperature, idle operation, constant speed operation, etc. of the internal combustion engine M5.

Next, the target step position calculating means M7 controls the throttle opening of the throttle valve M1 according to the operating state of the internal combustion engine M5 detected by the operating state detecting means M6, so that the step motor M2 determines the throttle opening. Specifically, the target step position is calculated according to the amount of depression of the accelerator pedal M4 detected by the accelerator position sensor of the driving state detection means M6, or the When the water temperature is low, adjust the target step position to the throttle valve M for warming up.
The target step position may be calculated by a method such as correcting it in the opening direction of 1 or by a method of feedback controlling the target step position so that the internal combustion engine M5 reaches the desired rotation speed during idling or low speed operation. .

The throttle opening detection means M9 detects the opening of the throttle valve M1 that is opened and closed by the step motor M2, and outputs an analog signal according to the opening, and is turned ON when the throttle valve M1 is fully opened. It is possible to use a fully open switch that is turned on at a predetermined opening of the throttle valve M1, or a reference opening switch that is turned on when the throttle valve M1 is opened at a predetermined opening. Further, as an abnormality detection means M10 that detects an abnormality of the device using the detection result of the throttle opening degree detection means M9 as one parameter,
As stated in the publication mentioned in the prior art section, an abnormality occurs when the deviation between the throttle opening detected by the throttle opening detection means M9 and the throttle opening estimated from the step position of the step motor M2 becomes large. It may be configured to detect. In the present invention, a biasing means M11 is provided that biases the throttle valve M1 in the fully closing direction, and when the step motor M2 is adjusted, the throttle valve M1 is rapidly rotated in the closing direction by the biasing means M1. Therefore, it is also possible to apply a potentiometer capable of constantly detecting the throttle opening degrees to the throttle opening detection means M9, and to detect an abnormality from the amount of change in the throttle opening over time, that is, the differential value thereof. .

Next, when an abnormality is detected by the abnormality detecting means M10, the drive signal output stopping means M13 and the step position initializing means M14 temporarily return the throttle valve M1 to the fully closed state, and set the step position at that time i-] III ]stomach)'
＃S 7 PL, -) っ TV
The step position of the step motor M2 controlled by the turning means M8 becomes the target step position, so that the opening/closing control of the throttle valve M1 can be executed normally again. In other words, if a tax adjustment occurs in the step motor M2 or if the drive signal to the step motor M2 cannot be properly transmitted, the step position stored in the step position initialization means M3 and the target step position calculated by the target step position calculation means M7. Although the actual step position matches the target step position, the actual step position is not controlled to the target step position, and an abnormality is detected by the abnormality detection means M10.
In this case, once the throttle valve M1 is fully closed and the step position at that time is initialized, normal opening/closing control can be performed again by the operation of the step motor driving means M8. Furthermore, drive signal output stop means M1
The reason why the throttle valve M1 is fully opened by stopping the output of the drive signal in step 3 is that when the drive signal is no longer output to the step motor M2, the step motor M' This is because the throttle valve M1 is rotated to the fully closed position by the urging means M11 and the stopper M12.

[Operation] In the throttle valve opening/closing control device of the present invention configured as described above, when an abnormality in the device is detected by the abnormality detection means MIO, the output of the drive signal to the step motor M2 is temporarily stopped. At the same time as the throttle valve is fully opened, the step position of the step position initializing means M3 is initialized. Therefore, step motor driving means M
8, the drive control of the step motor M2 is executed again from the initial state of the throttle valve being fully open.
The opening/closing control of the throttle valve M1 after the abnormality detection returns to the normal state again.

[Example] Embodiments of the present invention will be described below with reference to the drawings.

First, FIG. 2 is a schematic diagram showing the internal combustion engine and its peripheral devices in which the throttle valve opening/closing control device of this embodiment is mounted.

In the figure, 1 indicates an internal combustion engine, and an intake pipe 2 of this internal combustion engine 1 has a throttle opening sensor that is opened and closed by a step motor 4 to limit the amount of intake air upstream of a surge tank 3, and detects the opening degree of the intake pipe 2. A throttle valve 6 with 5 is provided.

Further, upstream of the throttle valve 6, an air filter 7 for purifying intake air and an air flow meter 8 for detecting the amount of intake air are provided.

On the other hand, 9 is a water temperature sensor that detects the cooling water temperature to detect the warm-up state of internal combustion engine 1, and 10 is a water temperature sensor that distributes high voltage generated by igniter 11 to the spark plugs of each cylinder in synchronization with the rotation of internal combustion engine 1. This distributor 10 is equipped with a rotation speed sensor 12 that outputs a pulse signal according to its rotation. Further, 13 is an accelerator position sensor that outputs a detection signal according to the amount of depression of the accelerator pedal 14, 15 is a vehicle speed sensor that detects the traveling speed of the vehicle in which the internal combustion engine 1 is mounted, and 16 is a sensor that detects the shift position of the transmission. Each shows a shift position detection sensor.

Above air flow meter 8, water temperature sensor 9, rotation speed sensor 1
2, accelerator position sensor 13, vehicle speed sensor 15,
and the shift position detection sensor 16h) are output to the electronic control circuit 20, respectively. The electronic control circuit 20 is mainly composed of a microcomputer, and calculates the fuel injection amount according to the operating state of the internal combustion engine 1 detected using each of the above-mentioned sensors, and performs fuel injection control to drive and control the fuel injection valve 22. At the same time, the opening of the throttle valve 6 is determined according to the operating state of the engine, such as the amount of depression of the accelerator pedal 14, and opening information representing the opening is output to the drive control circuit 24 of the step motor 4. Execute the degree calculation process.

Here, the throwers 1 to 1 outputted from the electronic control circuit 20 are
The opening information of the oil valve 6 represents the throttle opening calculated according to the operating state of the internal combustion engine 1. In this embodiment, this opening information is calculated from full open to full open of the thrower 1 to oil valve 6. The rotation angle is output as a digital signal representing the rotation angle in 0 to 720 steps. That is, the electronic control circuit 20 calculates the throttle opening degree determined according to the operating state of the internal combustion engine 1 by dividing the rotation angle of 81 degrees from full open to full open of the throttle valve into 720 parts of 0.1.
It is configured to divide by 125° and output the division result as a digital signal. Therefore, the electronic control circuit 20 outputs 10-bit information as opening degree information representing the throttle opening degree.

Next, as shown in FIG. 3, the throttle valve 6 is composed of a throttle body 31 that is part of the intake pipe 2, a butterfly valve 32, and a shaft 33 that rotatably fixes the butterfly valve 32. ,shirt! A throttle opening sensor 5 attached to one end of the butterfly valve 32 can detect the rotation angle of the butterfly valve 32, that is, the throttle opening. A gear 35 is attached to the other end of the shaft 33 and engages with a gear 34 attached to the rotating shaft 4a of the step motor 4, so that the butterfly valve 32 can be opened and closed by rotation of the step motor 4. Further, this throttle valve 6 includes a spring 37, one end of which is engaged with a pin 36 driven into the shirt 1, the other end fixed to the throttle body 31, and one end driven into the shaft 33. A stopper 38 whose other end abuts the throttle body 31 is provided, and a spring 37 urges the butterfly valve 32 in the closing direction, and a shaft 33 can stop the rotation of the butterfly valve 32 in the closing direction at the fully closed position. It is like that.

In this embodiment, the gear ratio between gear 34 and gear 35 is 1.
:2, and the step motor 4 is a 4-phase step motor that rotates by 0.9 degrees per step by 1-2 phase excitation.

Therefore, the throttle valve 6 is rotated by 0.45° per step of the step motor 4, and in order to calculate the target step position of the step motor according to the opening degree information output from the electronic control circuit 20, it is necessary to degree information 4
This means that all you have to do is divide by . In other words, since the opening information represents the throttle opening with a resolution of 0.1125° per step, dividing this opening information by 4 yields 0 per step, which is the same as the resolution of the step motor 4. Information representing the throttle opening degree can be obtained with a resolution of .45°, and this information can be used as is as the target step position of the step motor 4. In this embodiment, the value obtained by simply dividing the opening degree information by 4 is directly calculated as the target step position, and the target step position is duty-controlled according to the remainder as a result of the division. The average opening of 6 is the opening corresponding to the opening information, and the throttle opening is controlled with a higher resolution than that which can be realized by the step motor 4.

Further, the throttle opening sensor 5 includes a variable resistor whose resistance value changes depending on the opening of the throttle valve 6. By applying a predetermined voltage to this variable resistor, as shown in FIG. 0.5 when the throttle valve is fully open
V, a voltage signal (actual throttle level signal) that increases by 0.5 [V] every 10' throttle opening is obtained.

Next, the voltage signal from the detection signal section from the throttle opening sensor 5 is input to the drive control circuit 24 of the step motor 4 together with the opening information output from the electronic control circuit 20 . The drive control circuit 24 calculates a target step position of the step motor 4 based on the opening degree information, drives the step motor 4, and executes drive control of the step motor. Abnormality detection control is executed to detect an abnormality in the control device using the throttle opening and return the control to a normal state.

This drive control circuit 24, as shown in FIG. The drive circuit 43 drives the step motor 4 in accordance with a control signal output from the motor 41. In addition, one-chip microcomputer 4
1 is set by the clock 51 which sets the flag F every 2 [m5eC] based on the reference clock signal from the clock generator 42, and which sets the flag F every 600 [μsec] based on the reference clock signal from the clock generator 42. a programmable timer 52 that generates an interrupt request; an interrupt control circuit 53 that executes interrupt processing in response to the interrupt request;
A CPU 54 that executes step motor drive control and abnormality detection control, and a ROM 5 in which control programs and data necessary for the CPU 54 to execute arithmetic processing are recorded in advance.
5, R△M56 where data necessary for executing arithmetic processing by the CPU 54 is temporarily read/written, and opening information of the thrower 1 to valve 6 outputted from the electronic control circuit 20 are inputted, and the drive A human output buffer 57 that outputs a control signal to the circuit 43 and an A/D that converts the actual throttle level signal outputted from the throttle level sensor height 5 to Δ/D.
Hereinafter, the arithmetic processing executed by the one-chip microcomputer 41 configured as described above will be explained in detail with reference to the flowcharts shown in FIGS. 6 and 7.

In addition, FIG. 6 is executed every 600 [μsec] according to the pulse signal generated by the programmable timer 52 by the operation of the interrupt control circuit 53, and the step motor M
2, and FIG. 7 shows a target step that is repeatedly executed during operation of the internal combustion engine 1 and calculates a target step position required when driving the step motor 4 in the drive control routine of FIG. 6. It represents a position calculation routine.

In the drive control routine, first step 101 is executed,
The actual throttle opening (actual throttle opening) THI of the throttle valve 6 is read from the detection signal of the throttle opening sensor 5 inputted via the A/D converter 58, and the process proceeds to the next step 102. In step 102, the throttle opening T)-12 (estimated throttle opening) of the throttle valve 6 is estimated from the current step position N5TEP of the step motor 4. This estimated throttle opening T
The following equation (%) is used to estimate H2, and the estimated throttle opening TH2 is set to a value corresponding to the actual throttle opening TH1 read in step 101 above. In other words, step motor 4
When the rotation angle per step is 0.45°, the voltage signal output from the throttle opening sensor 5 changes by 0.05 [V] per 1°, and when the throttle valve 6 is fully opened, the throttle opening 5 The reference voltage output from
．． Since it is 5 [V], if we multiply N5TEP by 0.45 and 5/1008 and add 0.5 as above, we get
The estimated throttle opening TH2 corresponding to the detection signal output from the throttle opening sensor 5 can be calculated.

Next, in step 103, the difference ΔT between the actual throttle opening TH1 calculated in step 104 and the estimated throttle opening TH2 when the process of this routine was executed last time.
H is replaced with a reference value ΔTHO necessary for detecting the tax adjustment of the step motor 4 in a process described later, and the process proceeds to step 104. In step 104, the actual throttle opening TH1 read in step 101 and step 10
Deviation ΔT from the estimated throttle opening TH2 obtained in 2.
H is calculated and the process moves to the next step 105.

In step 105, the reference value ΔTHO set in step 103 and the deviation Δ obtained in step 104 are determined.
The rate of change ΔS of the deviation ΔTH is determined by using the following equation 8 with TH as a parameter, and the process proceeds to step 106. This process is performed by this routine at 600 [μ
sec], the deviation Δ within this time
To find the amount of change in TH. Therefore, the rate of change ΔS, that is, the differential value is calculated. Then, in the next step 106, it is determined whether or not the obtained change speed S is less than a predetermined value α (however, α is a negative value). Determine whether it has closed rapidly in the direction.

If it is determined in step 106 that ΔS>α has not caused step-out in the step motor 4, the following step 10
7 is executed, and it is then determined whether the absolute value of the deviation ΔTH obtained in step 104 is greater than or equal to a predetermined value. This is due to an abnormality in the control system other than step motor 4 stepping out, that is, the drive signal was not properly transmitted to step motor 4, or some abnormality in the power transmission system between step motor 4 and throttle valve 6. This is a process for detecting an abnormality such as a deviation in the opening degree of the throttle valve 6. If 1ΔTl-11≧1, it is determined that an abnormality has occurred, and the process proceeds to step 108. Increment the value of counter C1. On the other hand, if it is determined in step 107 that 1ΔTHl <K1, that is, if step-out of the step motor 4 is not detected in step 106 and no abnormality in the control system is detected in step 107, is step 109
Then, the value of the counter C1 is decremented by 10.

Next, when it is determined in step 106 that ΔS≦α that step motor 4 has lost synchronization, step 110 is executed, 20 is added to the value of counter C1, and step 11 is executed.
Move to 1. Then, in step 111, as in step 107, it is determined whether the absolute value of the deviation ΔTH is equal to or greater than the predetermined value. Increment. In addition, the above steps 107 and 11
The predetermined value used in 1 is set to a value obtained by adding a predetermined design margin to the detection setting of the throttle opening sensor 5.

On the other hand, if it is determined in step 111 that 1ΔTHl <K1, or if the value of counter C1 is changed in step 108, step 109 or step 112, step 113 is executed, and the value of counter C1 is changed. Determine whether the value is negative. and,
If C1<O, the value of the counter C1 is set to O in the next step 114 and the process proceeds to step 115; otherwise, the process directly proceeds to step 115. This process is performed when both the step motor 4 and the control system are normal.
Since the value of C1 is subtracted in step 109 and the value of C1 becomes negative, this process is performed to prevent this and prevent the value of C1 from becoming negative.

Next, in step 115, an abnormality in the device is confirmed based on the value of the counter C1 in a target step position calculation routine to be described later, and it is determined whether or not the flag F2 to be set is in the set state. If the flag F2 is set, the process proceeds to step 116, where the output of the control signal to the drive circuit 43 is stopped, and the processing of this routine is temporarily terminated.

On the other hand, if it is determined in step 115 that the flag F2 is in the reset state, the process moves to step 117, and the current step position is changed from the target step position TSTEP of the step motor 4 calculated in the target step position calculation routine to be described later. By subtracting the step position N5TEP of
Calculate the deviation Δ5TEP. And then step 11B
Now, determine whether this deviation Δ5TEP is positive or not,
If Δ5TEP>O, the process moves to step 119, and the value of N5TEP is increased by 1 in order to bring the step position N5TEP of the step motor 4 closer to the target step position lower 5TEP.
1'' is added, and the process moves to step 120.

Next, if it is determined in step 118 that the value of Δ5TEP is not positive, the process moves to step 121, and it is then determined whether the value of Δ5TEP is negative. If the value of Δ5TEP is negative, the process moves to the next step 122, where 11'' is subtracted from the value of N5TEP, and step 12
Transition to 0.

Further, if the value of Δ5TEP is not negative, that is, if Δ5TEP is rOJ and the target step position TSTEP and the current step position N5TEP match, the process directly proceeds to step 120.

In step 120, the lower 3 bits of N5TEP
Based on the value of , calculate the control signal pattern to be output to the drive circuit 43 using table data as shown in the following table,
The process proceeds to step 123, where a control signal corresponding to this control signal pattern is output, and the processing of this routine is temporarily terminated.

Table Here, in step 120 above, the lower 3bi of N5TEP
The above control signal pattern is calculated from t because the step motor is 4 or 4 phases and is driven by 1-2 phase excitation, so there are 8 drive signal patterns, and the lower 3
This is because the step motor 4 can be driven and controlled using only the bit step position information. Furthermore, the reason why the output of the control signal is stopped in step 116 is to stop the driving of the step motor 4 when an abnormality is detected in the step motor 4, and to drive the throttle valve 6 in the closing direction by the spring 37. Specifically, the control signal pattern may be set to roooOJ or "1111".

Next, in the target step position calculation routine shown in FIG.
In addition to calculating the target step position of the step motor 4, it also executes an abnormality detection process of detecting an abnormality in the control device based on the value of the counter C1 counted in the drive control routine.

When this process starts, step 200 is first executed,
It is determined whether the flag F1, which is set every 2 [m5eC] by the clock 51, is set. If the flag F1 is in the reset state, the process moves to the next step 201, and the process moves to step 202, where 1Qbit opening degree information ITSTEP outputted from the electronic control circuit is read.

In step 202, the upper 8 bits of the opening information ITSTEP read in step 201 are set as the reference step position 8-5TEP of the step motor 4, and the process proceeds to step 203. As mentioned above, in this process, the opening information ITSTEP is 0.1'1 per step.
It expresses the throttle opening with a resolution of 25 degrees.
0 per step realized by step motor 4
To express the throttle opening with a resolution of 45°,
Since it is sufficient to divide the opening information ITSTEP by "4", the opening information ITSTEP can be obtained by removing the lower 2 bits.
STEP is divided by "4" and the value is set as the reference step position BTSTEP which will be used as a reference when determining the target step position of the step motor 4 in the process described later.

Next, in step 203, the lower two bits of the opening information ITSTEP read in step 201 are
t, that is, the remainder obtained by dividing the opening information ITSTEP by "4", is used as duty data DTS to be used for duty-controlling the step position of the step motor 4 in the processing described later.
It is set as TEP, and the process moves to the next step 204.

In step 204, it is determined whether a flag F2, which is set when an abnormality in the device is confirmed in steps 205 and 206 described later, is set, and if flag F2 is set, this routine is temporarily stopped. After completing the process, the process returns to step 200. Meanwhile, step 2 above
If it is determined in step 04 that the flag F2 is not set, the process moves to step 205. and step 2
In step 05, it is determined whether the value of the counter C1 counted in the drive control routine has reached a predetermined value of 2, for example 100 or more. If C1≧2, it is assumed that an abnormality has occurred in the control device, and the process moves to step 206, where the flag F2 is set and the step position N5TE is set.
P, initialize the counter C1, and proceed to step 2.
00. Also, if C1<K2, step 2
The process moves to step 07, the value of the counter C2 is cleared, and the process moves to step 200.

Here, the process of step 205 is a process for preventing erroneous detection of an abnormality in the device due to a sudden closing of the throttle valve 6 or a delay in response of the control that occurs when the throttle valve 6 is suddenly closed. An abnormality in the device is confirmed by determining whether or not the value of a count C1, which is counted up by 20 when a step-out is detected, and which is counted up by 1 when an abnormality occurs in other control systems, is abnormal to a predetermined value. There is. Therefore, if the value of 2 is 100, the state of 1 in ΔTH≧ is 60 [m5eC] (
= 100x0.6 [m5ec]) or more, or the state of ΔS≦α is 3 [m5eC] (=100x0
．． If the problem continues for more than 6/20 [m5ec], an abnormality will be confirmed. Further, in step 206, the flag F2 is set, and the step position N5TEP and the counter C1 are initialized. This is because setting the flag F2 stops outputting the control signal in the drive control routine described above, and the throttle valve 6 is stopped. This is a process for setting the throttle valve to the fully open state, initializing the step position N3 EP, and re-executing the opening/closing control of the throttle valve 6 from the initial state of the throttle valve fully open.

Next, if it is determined in step 200 that the flag F1 is set, the process proceeds to step 208, where the flag F1 is reset and the counter C3 is incremented.In step 209, this increment is It is determined whether the value of the counter C3 is 4 or more, and if C3≧4, the process moves to step 210 and the value of the counter C3 is cleared.

On the other hand, if it is determined in step 209 that C3<4, or if the value of counter C3 is cleared in step 210, the process moves to step 211,
This time, it is determined whether the value of the counter C3 is greater than or equal to the duty data DTSTEP set in step 204, that is, the remainder of the opening degree information divided by 4. If it is determined in this step 211 that C3≧DTSTEP, the process moves to step 212, and the step motor 4 moves to the target step position TSTEP in step 203.
The reference step position BTSTEP set in step 2 is set as is, and the process moves to step 214. On the other hand, if it is determined in step 211 that C3<DSTEP, the process moves to step 213, and the value obtained by adding 1 to the reference step position BTSTEP is set to the target step position T.
It is set as STEP, and the process moves to step 214.

Here, the processing of steps 208 to 212 is performed by comparing the value of the counter C3, which changes from O to 3 every 2 [m5ec], with the duty data DTSTEP, which is the lower 2 bit information of the opening information ITSTEP. The duty ratio corresponding to the remainder when the opening information ITSTEP is opened by 4 (in this example, 25%, 50%, 7
5%) according to the standard step position @BTsTE
This is a process for duty-controlling the target step position TSTEP of the step motor 4 so that the average opening of the throttle valve 6 corresponds to the opening information ITSTEP by adding 1 to P. In this embodiment, this duty control is 2 [m5ec]×4, that is, 3 [m5ec]
] It will be executed periodically.

Next, in step 214, it is determined whether the flag F2 is in the cella 1~ state, and if the flag F2 is in the reset state, the process directly proceeds to step 200. On the other hand, if the flag F2 is set, that is, step 20
If it is determined in step 5 that an abnormality has occurred in the device, the process moves to step 215 and the value of the counter C2 is incremented. Then, in the next step 216, it is determined whether or not the value of the counter C2 exceeds a predetermined value of 3, for example 100. If C2>K3, the process proceeds directly to step 216.
Move to 1. If C2≦3, the flag F2 is reset in step 217, and then step 20
Transition to 0.

Here, the processing of steps 214 to 217 is performed after an abnormality in the device is detected and the flag F2 is set to 1 to 1, and then the output of the control signal of the step motor 4 is stopped for a predetermined period of time in the drive control routine. This is a process for controlling the throttle valve 6 so that the throttle valve 6 is completely opened. In other words, when the output of the control signal of the step motor 4 is stopped, the throttle valve 6
is rotated in the closing direction by the spring 37 and stopped at the fully open position by the stopper 38, but at this time, the stopper 38 bounces due to the reaction, and the throttle opening may fluctuate as shown in FIG. If control is resumed immediately after the control signal stops, the step position of the step motor 4 will be determined to be the fully open position of the throttle valve 6 even though it is not the fully open position of the throttle valve 6. The output of the control signal is stopped until the valve 6 is fully opened. In addition, if the predetermined value of 3 is set to 100 in the above process, the counter C2 is cycled every 2 [m5ec], so the output stop time of the control signal (the set time of the flag F2) is As shown in Figure 8, 200 [m5ec] (=
100x2 [m5ec]).

In the throttle valve opening/closing control device of this embodiment configured as described above, when step motor 4 loses synchronization as shown in FIG. An abnormality in the device is confirmed, and flag F2 is set.
is set for 200 [m5ec]. During this time, the step position is set to the initial value O, and the throttle valve 6 is fully closed. and 200 [m5
eC] When the flag F2 is reset, the opening/closing control is restarted, the step position becomes the target step position, and the control returns to the normal state. Therefore, according to the opening/closing control device of this embodiment, after detecting an abnormality in the device, it is possible to restore the normal state again, so there is no need to temporarily stop the internal combustion engine and repair it, and the engine can continue to operate as is. can improve safety.

On the other hand, in this embodiment, the result of dividing the opening degree information output from the electronic control circuit to the resolution that can be achieved by the step motor 4 is not directly used as the target step position of the step motor 4, but the remainder is determined according to that value. With a duty ratio of 1
Since the step motor 4 is driven and controlled using the added value as the target step position, the average opening degree of the throttle valve 6 can be controlled with a resolution higher than that which can be achieved by the step motor 4. It is also possible to improve the accuracy of opening/closing control.

As described above, in the above embodiment, the drive control circuit 24 was constructed using the one-chip microcomputer 41. Next, as another embodiment of the present invention, the drive control circuit 24 is constructed using an electronic circuit that does not use a microcomputer. The opening/closing control device will be explained. In this embodiment, the configuration of the electronic control circuit 20, step motor 4, throttle opening sensor 5, etc. is completely the same as in the previous embodiment, and only the circuit configuration of the drive control circuit 24 is different.

As shown in FIG. 9, the drive control circuit 60 of this embodiment first includes an oscillator 61 that outputs a 1600H2 pulse signal, and divides the 1600H2 pulse signal output from the oscillator 61 by 1720 to generate an 80H2 pulse signal. The output frequency divider 62, the 2-bit counter 63 that counts the pulse signal from this frequency divider 62, and the lower order of the 2-bit information output from this counter 63 and the opening degree information output from the electronic control circuit 20-. Compare with 2 bits of information,
When these pieces of information match, a comparator 64 outputs a high level signal, and a counter 637Js outputs a high level signal.
NOR circuit 6 configured using an AND element to output a signal at H1gh level when bit information is rOJ
5, and an R-S flip-flop 66 that is set by the output signal of the NOR circuit 65 and reset by the output signal from the comparator 64, and divides the opening information from the R-S flip 70 knob 66 by 4. 50 [m5ecl (=4/80H
1 is generated every 2>.

Further, this drive control circuit 60 contains the information of the electronic control circuit 2n'light 2-h-A: fishing bass dark side method introduction ra starvation μJMQhit and 5Q [m5ec] from the R-S flip-flop 66.
An 8-bit adder 67 adds the duty signals outputted every time and outputs a target step position signal, and compares the target step position signal A from this adder 67 with the current step position signal B. , up/down counter 68
an up/down counter 68 that counts up or down at 1600H7 according to a control signal output from the comparator 69 and outputs a step position signal; The step motor 4 is activated in accordance with the step information of the lower 3 bits according to the pattern shown in the figure.
A decoder 70 that outputs a drive signal of - and a drive circuit 71 that drives the step motor 4- in accordance with the drive signal are provided, and as in the previous embodiment, the target step position of the step motor 4' is duty-controlled. , the throttle opening can be controlled with a resolution higher than that which can be realized by the step motor 4'.

Furthermore, this drive control circuit 60 estimates the throttle opening of the throttle valve by D/A converting the step position signal output from the up/down counter 68, and uses this estimated throttle opening and a throttle opening sensor. Based on the detected actual throttle opening, an abnormality in the device is detected, and the step position signal is D/A converted to restore the normal state, and the step position changes by 0 to 256 steps as shown in Fig. 10. O accordingly
~5[V] An abnormality is detected from the D/A converter 72 that outputs the changing estimated throttle opening signal @Vn, this estimated throttle opening signal yn, and the actual throttle opening signal vth from the throttle opening sensor 5'. An abnormality detection control circuit 73 is provided to detect the abnormality and return the device to a normal state. The step motor 4' opens and closes the throttle valve by 0.45 degrees per step, and the throttle valve opens and closes by 0.45 degrees per step.
1 degree, the step position signal changes only within the range of 0 to 180 steps, and the estimated throttle opening signal vn actually output from the D/A converter is shown by the dotted line in Fig. 10. Thus, the voltage is O~3.52 [V].

As shown in FIG. 10, the abnormality detection circuit 73 makes the estimated throttle opening signal vn outputted from the D/A converter 7-2 correspond to the actual throttle pulse level signal vth outputted from the throttle opening sensor, An arithmetic circuit 81 that calculates the absolute value Vd of the deviation, a comparison circuit 82 that determines whether Vd exceeds a predetermined value Vα, and a control circuit that detects an abnormality in the control system if the state of Vd>Vd continues for a predetermined period of time. a delay circuit 83 that outputs an abnormality detection signal as a signal, and a differentiation circuit 84 that differentiates the deviation VX obtained during the calculation of the calculation circuit 81.
and a comparison circuit 85 which judges whether or not this differential value VX is less than a predetermined value ■β, and outputs a tax adjustment detection signal as if a tax adjustment has occurred in the step motor 4- when VX<Vn; The control stop circuit 86 receives a detection signal from the comparison circuit 85 or the delay circuit 83, resets the up/down counter 68 for a predetermined period of time, and stops the output of the drive signal from the drive circuit 71.

Here, the arithmetic circuit 81 calculates the absolute value Vd of the deviation using the following formula % 25615: Number of steps per Vn 1 [V] 5
/100: vthO per 1° throttle opening, 4
5: The estimated throttle amount signal is calculated from the value obtained by multiplying the actual throttle opening signal vth input via the buffer consisting of operational amplifier OP1 by 1/1.152 so as to calculate the throttle opening per step. Subtract (0.5/'1.152) [V] applied from Vn and battery B1, and the deviation VX ((Vth/1.152) -
(0,052/1.152) - A differential amplifier circuit configured using an operational amplifier OP2 to calculate Vn, and an operational amplifier OP3 and OR3 to multiply this numbing result by 1.152 and obtain its absolute value. and an absolute value amplification circuit configured using Further, the comparison circuit 82 is configured using an operational amplifier OP5, and outputs a signal at the )-1high level when the absolute value Vd of the deviation exceeds the allowable voltage Vα. Note that this allowable voltage Vα is set to a value obtained by adding a predetermined design margin to the detection error of the throttle opening sensor 5, as in step 104 shown in FIG. Furthermore, the delay circuit 83 uses an integration circuit consisting of a capacitor and a resistor, and if a high level signal is output from the comparison circuit 82 for a predetermined period of time determined by the time constant of the integration circuit, it is determined that an abnormality has occurred in the control system. as op amp O
An abnormality detection signal is output via a buffer consisting of P6.

On the other hand, the differentiating circuit 84 is connected to the operational amplifier OP of the arithmetic circuit 81.
The comparator circuit 85 is configured to input the output voltage, that is, the deviation VX, of the differential amplifier circuit configured using the differential amplifier circuit 84 using the differential amplifier circuit 84 via the buffer consisting of the operational amplifier OP7, and differentiate it using the CR filter. Voltage V output from
The operational amplifier OP8 is configured to compare has been done.

Further, the control stop circuit 86 resets the up/down counter 68 for a predetermined time and stops driving the step motor 4' when the step-out or abnormality detection signal is output from the comparison circuit 85 or the delay circuit 83. OR circuit O
It consists of R1 and a monostable multivibrator 87, and is designed to stop and initialize control.

In the throttle valve opening/closing control device of this embodiment configured as described above, as in the previous embodiment, when an abnormality occurs in the opening/closing control of the throttle valve, it is not only possible to accurately detect the abnormality, but also to By stopping the drive of the time step motor and initializing the step position stored in the up/down counter, it is possible to return to normal opening/closing control from the initial state of fully closed throttle valve.

[Effects of the Invention] As detailed above, according to the throttle valve opening/closing control of the present invention, when the step motor loses synchronization and the throttle valve opening/closing control cannot be performed satisfactorily, this fact is simply detected. In addition, it becomes possible to return the throttle valve to normal control from its idle initial state, thereby improving the safety of the device. Therefore, it is not necessary to temporarily stop the operation of the internal combustion engine and repair it when an abnormality is detected as in the conventional case, and the internal combustion engine can be continued to be operated.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of the present invention, FIGS. 2 to 8 show an embodiment of the present invention, and FIG. 2 shows an engine equipped with a throttle valve opening/closing control device and its peripheral equipment. A schematic configuration diagram; FIG. 3 is a configuration diagram showing the configuration of the throttle valve, step motor, and throttle opening sensor; FIG. 4 is a diagram showing the actual throttle opening signal output from the throttle opening sensor; FIG. 5 6 is a block diagram showing a drive control circuit that drives the step motor, and FIG. 6 is a flowchart showing a drive control routine executed every 600 [μsec] in the W drive control circuit.
FIG. 7 is a flowchart showing a target step position calculation routine that is repeatedly executed by the drive control circuit, FIG. 8 is a time chart explaining the operation of this embodiment, and FIGS. 9 is an electric circuit diagram showing the circuit configuration of the drive control circuit, and FIG. 10 is an electric circuit diagram showing the circuit configuration of the drive control circuit.
A diagram showing the estimated throttle opening signal output from the /A converter 72, and FIG. 11 is an electric circuit diagram showing the circuit configuration of the abnormality detection control circuit 73. Ml,6...Throttle valve M2,4...Step motor M3...Step position initializing means M4.14...Accelerator pedal M5,1...Internal combustion engine M6...Operating state detecting means Ml ...Target step position extraction means M8...Step motor drive means M9...Throttle distance detection means M10...Abnormality detection means Mll...Biasing means M12.38...Stopper M13... - Drive signal output stop means M14...Step position initialization means 5...Throttle opening sensor 11...Accelerator position sensor 20...Electronic control circuit 24...Drive control circuit 37...Spring 41 ...One-chip microcomputer 42...
Clock generator 43...drive circuit

Claims (1)

[Scope of Claims] A step motor that opens and closes a throttle valve, step position storage means that stores the step position of the step motor, and operating state detection means that detects the operating state of the internal combustion engine, including at least the amount of depression of the accelerator pedal. and target step position calculation means for calculating a target step position of the step motor according to the detection result of the operating state detection means; and the calculated target step position and the step position stored in the step position storage means. step motor drive means for comparing the step position with the step position and outputting a drive signal to the step motor so that the step position becomes a target step position, and updating the step position stored in the step position storage means in accordance with the drive signal; , a throttle opening detection means for detecting the opening of the throttle valve; and an abnormality detection means for detecting an abnormality in the device using the detection result of the throttle opening detection means as one parameter. In the control device, an abnormality in the device is detected by the urging means for urging the throttle valve in the closing direction, the stopper for restricting the movement of the throttle valve in the closing direction to a fully closed position, and the abnormality detection means. a drive signal output stop means for temporarily stopping the output of the drive signal from the step motor drive means; and a drive signal output stop means for temporarily stopping the output of the drive signal from the step motor drive means; 1. A throttle valve opening/closing control device comprising: step position initializing means for initializing a step position.