JP2616768B2 - Throttle valve control device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a throttle valve control device.

[Conventional technology]

Conventionally, there is provided a step motor for opening and closing a throttle valve in order to precisely control an intake air amount according to an operation state of an engine, and the step position of the step motor is stored and the stored step position is determined by the operation state of the engine. 2. Description of the Related Art There is known a throttle valve control device that controls a step motor so as to reach a target step position.
This throttle valve control device has an advantage that the control device can be simplified because open / close control of the throttle valve can be performed by open loop control. However, when such an open loop control is used, when a deviation occurs between the actual step position of the step motor and the stored step position, the actual opening of the throttle valve is set to the target opening determined from the target step position. Therefore, there arises a problem that accurate opening / closing control of the throttle valve becomes impossible.

In order to solve such a problem, a throttle full-close switch for detecting a throttle reference opening slightly larger than the throttle valve full-close position is provided, and when the throttle valve reaches the throttle reference opening, the target step position and A throttle valve control device that matches the stored step position has already been proposed by the present applicant (see Japanese Patent Application No. 60-236785).

On the other hand, when the throttle valve is controlled by the step motor in this way, it is dangerous if the throttle valve continues to be opened for some reason when the accelerator pedal is released. Therefore, a throttle lever that rotates together with the throttle valve and an accelerator link that is connected to the accelerator pedal and engages with the throttle lever when the accelerator pedal is released to forcibly rotate the throttle valve to the fully closed position are provided. Such a throttle valve control device has already been proposed by the present applicant (see Japanese Patent Application No. 61-148071).

[Problems to be solved by the invention]

As described above, in the throttle valve control device described in Japanese Patent Application No. 61-148071, when the accelerator pedal is released, the throttle valve is fixedly held at the fully closed position by the accelerator link. Therefore, in such a case, the throttle valve cannot be opened to the throttle reference opening as described in Japanese Patent Application No. 60-236785, and therefore, the target step position matches the stored step position. Control cannot be performed.

[Means for solving the problem]

In order to solve the above problems, according to the present invention, there is provided a step motor for opening and closing a throttle valve, a step position to be taken by the step motor is stored in a memory, and a storage step position stored in the memory is stored. In a throttle valve control device which gradually changes toward a target step position and changes the actual step position of a step motor in accordance with a change in a stored step position, a throttle slightly larger than a throttle valve fully closed position. A throttle full-close switch for detecting a reference opening; a throttle lever that rotates together with the throttle valve; and an accelerator link connected to the accelerator pedal and engaged with the throttle lever to regulate the maximum opening of the throttle valve. When the accelerator link is at the maximum return position The maximum opening of the throttle valve is regulated by the accelerator link is larger than the throttle reference opening, so that match the target step position storage step position when the throttle valve is turned throttle reference opening.

〔Example〕

Referring to FIG. 4, reference numeral 1 denotes an engine main body, 2 denotes a surge tank, and 3 denotes an intake pipe. Inside the intake pipe 3, a throttle valve 6 controlled to be opened and closed by a step motor 4 is disposed. A throttle sensor 5 for detecting the opening of the throttle valve 6 is connected to the throttle valve 6. Further, in FIG. 4, 7 is an air cleaner, 8 is an air flow meter for detecting an intake air amount, 9 is a water temperature sensor for detecting engine cooling water temperature, 10 is a distributor, 11 is an igniter, 12 is mounted on the distributor 10, and a crankshaft is mounted. A rotation speed sensor that generates an output pulse each time the vehicle rotates by a predetermined crank angle, 13 is an accelerator position sensor that generates an output signal corresponding to the depression amount of an accelerator pedal 14, 15 is a vehicle speed sensor that detects a vehicle speed, Reference numeral 16 denotes a shift position detection sensor for detecting a shift position of the transmission. These air flow meter 8, water temperature sensor 9, rotation speed sensor 12, accelerator position sensor 13,
Detection signals from the vehicle speed sensor 15 and the shift position detection sensor 16 are input to the electronic control circuit 20. The electronic control circuit 20 is mainly composed of a microcomputer, and calculates a fuel injection amount from detection signals of these sensors to calculate a fuel injection amount.
Of the throttle valve 6 according to the operating state of the engine, such as the amount of depression of the accelerator pedal 14.
Then, a throttle opening production process is executed in which the target opening is obtained and the opening information representing the target opening is output to the drive control circuit 22 of the step motor 4.

The electronic control circuit 20 outputs the opening degree information of the throttle valve 6 as a digital signal representing the rotation angle from the fully closed state to the fully opened state of the throttle valve 6 in 0 to 720 steps. That is, the electronic control circuit 20 divides the throttle opening determined according to the operating state of the internal combustion engine 1 by a value of 0.1125 ° obtained by dividing the rotation angle 81 ° from the fully closed state to the fully opened state of the throttle valve into 720, and calculates The division result is output as a digital signal. Therefore, the electronic control circuit 20 outputs 10-bit information as the opening information indicating the throttle opening.

Referring to FIGS. 1 and 2, the throttle valve 6 is supported by a valve shaft 23, which is rotatably supported by a throttle body 24 forming a part of the intake pipe 3. Valve shaft
One end of 23 is connected to a throttle sensor 5 for detecting the opening of the throttle valve 6, and a throttle lever 25 is fixed to the other end of the valve shaft 23. On the other hand, an arm 27 is fixed to an output shaft 26 of the step motor 4.
A roller 28 is rotatably attached to the tip of the roller. Also,
A coil spring 29 that constantly biases the throttle valve 6 in the valve opening direction is provided between the valve shaft 23 and the throttle body 24.
(FIG. 1) is inserted, and the throttle lever 25 is pressed against the roller 28 by the spring force of the coil spring 29. Therefore, the step motor 4 is driven and the arm
When 27 rotates, the throttle lever 25 also rotates, and thus the throttle valve 6 also rotates. In this way, the opening and closing of the throttle valve 6 can be controlled by the step motor 4. Further, the fully closed position of the throttle valve 6 (hereinafter, fully closed position means an idling angle)
A throttle lever stopper 30 engageable with the throttle lever 25 is provided to determine The throttle lever stopper 30 is composed of an adjusting screw 32 screwed to the protrusion 31 of the throttle body 24.

On the other hand, above the valve shaft 23, the accelerator shaft
The accelerator shaft 33 is rotatably supported by the throttle body 24. An accelerator position sensor 13 is attached to one end of an accelerator shaft 33, and an accelerator link 34 is fixed to the other end. A coil spring 35 is provided between the accelerator shaft 33 and the throttle body 24.
(FIG. 1) is inserted, and the accelerator link 34 is constantly urged clockwise in FIG. 2 by the spring force of the coil spring 35. The accelerator link 34 is connected to the accelerator pedal 14 (FIG. 4) via a wire (not shown). When the accelerator pedal 14 is depressed, the accelerator link 34
Is turned counterclockwise in FIG. On the other hand, an accelerator link stopper 36 engageable with the accelerator link 34 is integrally formed on the throttle body 24. When the accelerator pedal 14 is released, the accelerator link 34 rotates clockwise in FIG. 2 until the accelerator link 34 engages with the accelerator link stopper 36. To rotate. Pin 37 at the lower end of accelerator link 34
A roller 38 engageable with the throttle lever 25 is rotatably mounted on the pin 37.

A broken line A in FIG. 3 shows an example of the accelerator pedal depression amount and the opening degree of the throttle valve 6 controlled by the step motor 4. On the other hand, if the opening degree of the throttle valve 6 is gradually increased while the accelerator pedal depression amount is kept constant, the throttle valve 6 cannot be opened any more when the throttle lever 25 comes into contact with the roller 38 of the accelerator link 34. . That is, the maximum opening of the throttle valve 6 is determined by the accelerator pedal depression amount, in other words, the position of the accelerator link 34, and the maximum opening of the throttle valve 6 regulated by the accelerator link 34 is the third opening.
This is indicated by the solid line B in the figure. When the throttle valve 6 is normally controlled by the step motor 4, the throttle opening changes as shown by a broken line A in FIG.
No contact with 25. However, if for some reason the throttle opening with respect to the accelerator depression amount increases and the throttle lever 25 comes into contact with the roller 38 of the accelerator link 34, the throttle opening is regulated to the opening shown by the solid line B in FIG. As the accelerator depression amount decreases, the throttle valve opening gradually decreases along the solid line B. That is, the throttle valve 6 is forcibly rotated in the valve opening direction by the accelerator link 34.

P ₁ in Figure 3 shows the fully closed position of the throttle valve 6 which is determined by the throttle lever stopper 30. On the other hand, P ₂ is an accelerator link 34 is an accelerator link stopper 36
5 shows the maximum opening of the throttle valve 6 when the throttle valve 6 is at the maximum return position where the throttle valve 6 comes into contact. Therefore, from FIG. 3, this maximum opening P ₂
Is greater than the total閉地position P _1, thus the throttle valve 6 is fully closed position P ₁ when the accelerator pedal 14 is released
It can be seen that can pivot between an maximum opening P ₂ and.

In the embodiment shown in FIG. 1 and FIG. 2, the rotation speed of the throttle valve 6 is configured to be half of the rotation speed of the step motor 4, and the step motor 4 has a rotation speed of 1-2 by 1-2 phase excitation. A four-phase step motor that rotates 0.9 degrees per step is used. Therefore, the throttle valve 6 is set to 0.
Can be rotated 45 ゜. However, as described above, since the electronic control circuit 20 outputs the opening information at every 0.1125 °, the opening information is divided by 4 to calculate the target step position of the step motor 4 according to the opening information. That's it. If the opening information is divided by 4, the same information as that of one step of the step motor 4 can be obtained which indicates the throttle opening every 0.45 °, and this information can be used as it is as the target step position of the step motor 4.
In the present invention, the value obtained by simply dividing the opening information by 4 is not directly calculated as the target step position, but the duty of the target step position is controlled in accordance with the remainder obtained as a result of the division. By doing so, the average opening of the throttle valve 6 becomes the opening corresponding to the opening information, and the throttle opening can be controlled with high accuracy.

The throttle sensor 5 includes a variable resistor 5a whose resistance value changes according to the opening of the throttle valve 6, and a throttle full-close switch 5b for detecting a throttle reference opening. The variable resistor 5a is 0.5 [V] when the throttle is fully closed as shown in FIG.
電 圧 Generate a voltage signal (actual throttle opening signal) that increases by 0.5 [V] every time it increases. On the other hand, the throttle fully closed switch 5b is provided for detecting a throttle reference opening as described above, the throttle reference opening is indicated by P ₃ in Figure 3. Incidentally, the throttle fully closed switch 5b in the present invention is configured to generate an ON signal when the opening degree of the throttle valve 6 is equal to or less than the throttle reference opening P _3. Third The throttle reference opening P ₃ As can be seen from the figure the fully closed up to the opening P ₂ and the throttle valve 6 of the throttle valve 6 when in the maximum return position accelerator link 34 is in contact with the accelerator link stopper 36 It is located midway between the position P _1. The distance between P ₁ and P ₃ is approximately 1.5 degrees with the throttle opening degree, P ₃ and P ₂
Is about 1.5 degrees with the throttle opening.

The detection signal from the throttle sensor 5 is input to the drive control circuit 22 of the step motor 4. The drive control circuit 22 calculates the target step position of the step motor 4 based on the opening degree information from the electronic control circuit 20, and controls the drive of the step motor 4.

As shown in FIG. 6, the drive control circuit 22 includes a one-chip microcomputer 41, a clock generator 42 for supplying a reference clock pulse to the one-chip microcomputer 41, and a control signal output from the one-chip microcomputer 41. And a drive circuit 43 for driving the step motor 4. The one-chip microcomputer 41 sets the flag F1 every 2 [msec] based on the reference clock signal from the clock generator 42, and an interrupt request every 600 [μsec] based on the reference clock signal from the clock generator 42. , An interrupt control circuit 53 for executing an interrupt process in response to the interrupt request, a CPU 54 for performing drive control of the step motor 4, and a CPU 54 for performing arithmetic processing. Read-only memory (ROM) 55 in which various control programs and data are recorded in advance, a random access memory (RAM) 56 in which data necessary for executing arithmetic processing by the CPU 54 are temporarily read and written, and an electronic control circuit 20
Input / output buffer 57 for inputting the opening degree information of the throttle valve 6 and the detection signal from the throttle full-close switch 5b of the throttle sensor 5 and outputting a control signal to the drive circuit 43; And an A / D converter 58 for A / D converting the detection signal detected by the device 5a.

Hereinafter, the arithmetic processing executed by the one-chip microcomputer 41 will be described with reference to FIGS. 7 to 9. FIG. 7 shows a drive control routine of the step motor 4 executed every 600 [μsec] in response to a pulse signal generated from the programmable timer 52.
FIG. 8 shows a target step position calculation routine for calculating a target step position, and FIG.
2 shows an initialization processing routine for matching the storage step position with the target step position.

Referring to FIG. 7, first, at step 122, the deviation ΔSTEP is calculated by subtracting the current storage step position NSTEP from the target step position TSTEP of the step motor 4 calculated by the target step position calculation routine described later. . Next, at step 123, it is determined whether or not the deviation ΔSTEP is positive. If ΔSTEP> 0, the routine proceeds to step 124, where NSTEP is set so that the stored step position NSTEP of the step motor 4 approaches the step position TSTEP. "1" is added to the value, and the routine proceeds to step 125.

On the other hand, if it is determined in step 123 that the value of ΔSTEP is not positive, the process proceeds to step 126, and it is determined whether the value of ΔSTEP is negative. If the value of ΔSTEP is negative, the routine proceeds to step 127, where “1” is subtracted from the value of NSTEP, and the routine proceeds to step 125. If the value of ΔSTEP is not negative, ie, ΔS
When TEP is “0” and the target step position TSTEP matches the storage step position NSTEP, the process proceeds to step 125.

In step 125, a control signal pattern to be output to the drive circuit 43 is calculated using the data map shown in the following table based on the lower 3 bits of NSTEP. Then step 12
Proceeding to 8, a control signal corresponding to this control signal pattern is output, and the processing of this routine ends.

Here, in step 125, the control signal pattern is calculated from the lower 3 bits of NSTEP because the step motor 4 has 4 phases and is driven by 1-2 phase excitation, so that the drive signal pattern has 8 patterns, and therefore the lower 3 bits. This is because the drive of the step motor 4 can be controlled only by the step position information.

Next, the target step position calculation routine shown in FIG. 8 will be described. In this routine, a target step position of the step motor 4 is calculated.

When this process is started, first, in step 200, the flag F1 set every 2 [msec] by the clock 51 in step 200
It is determined whether or not is set. If the flag F1 has been reset, the routine proceeds to step 201, where the electronic control circuit 20
Reads 10-bit opening information ITSTEP output from. Next, in step 202, the upper 8 bits of the opening information ITSTEP read in step 201 are set as the target step reference position BTSTEP of the step motor 4. That is, as described above, the opening information ITSTEP represents the throttle opening every 0.1125 °. To use this as the drive signal for the step motor 4, the opening information ITSTEP may be divided by “4”. Therefore, the opening degree information ITSTEP is divided by "4" after removing the lower 2 bits, and the value is set as a target step reference position BTSTEP which is a reference when determining a target step position of the step motor 4 in a process described later.

Next, at step 203, the lower 2 bits of the opening information ITSTEP read at step 201, that is, the opening information ITSTP,
The remainder obtained by dividing EP by “4” is set as duty data DTSTEP used for duty control of the step position of the step motor 4 in the processing described later.

On the other hand, when 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 value of the counter C3 is incremented. Next, in step 209, it is determined whether or not the value of the incremented counter C3 is 4 or more.
If ≧ 4, the routine proceeds to step 210, where the value of the counter C3 is cleared.

On the other hand, if it is determined in step 209 that C3 <4, the process proceeds to step 211, and it is determined whether or not the value of the counter C3 is equal to or greater than the remainder of the duty data DTSTEP set in step 203, that is, the opening degree information 4. Judge. C3 ≧
When it is determined that it is DTSTEP, the process proceeds to step 212, where the target step position TSTEP of the step motor 4 is set to the target step position BTSTEP set in step 202. On the other hand, if it is determined in step 211 that C3 <DSTEP, the process proceeds to step 213, where the target step position BTS
A value obtained by adding 1 to TEP is set as the target step position TSTEP.

Here, the processing from step 208 to step 213 is 2 [ms
ec] and the value of the counter C3 that changes from 0 to 3 each time and the duty data DTSTEP which is the lower 2 bits of the opening degree information ITSTEP
Compared to the duty ratio corresponding to the remainder obtained by dividing the opening information ITSTEP by 4 (in this embodiment, 25%, 50%, 75%
1) is added to the reference step position BTSTEP according to any one of the above, so that the target step position TSTEP of the step motor 4 is duty-set so that the average opening of the throttle valve 6 becomes an opening corresponding to the opening information ITSTEP. This is a process for controlling. In the present invention, the duty control is performed at a cycle of 2 [msec] × 4, that is, 8 [msec].

FIG. 9 shows the stored step position NSTEP of the step motor 4.
7 shows an initialization process for matching the target step position TSTEP with the target step position TSTEP. In the embodiment shown in FIG. 9, the initialization process is performed at the time of starting the engine.

Referring to FIG. 9, first, at step 300, it is determined whether or not the engine is being started. Here, the start of the engine means a period from when the ignition switch is turned on to when the starter motor is operated, that is, when the engine is stopped. At this time, no control signal is supplied to the step motor 4. On the other hand, since the throttle valve 6 is urged in the valve opening direction by the spring force of the coil spring 29, the throttle valve 6 is held at the opening position where the throttle lever 25 is in contact with the accelerator link 34 against the roller 38. throttle valve 6 is in the opening indicated by P ₂ in Figure 3. That is, the throttle valve 6 is larger than the throttle reference opening P _3.

If the engine is started, the routine proceeds to step 301, where the storage step position NSTEP is set to 100, and the target step position TSTEP is set to 100.
It is said. This numerical value 100 does not necessarily have to be 100, and may be any numerical value as long as it is a certain large value. Next, at step 302, the flag F set every 2 [msec]
Wait until 1 is set. When the flag F1 is set, the routine proceeds to step 303, where the flag F1 is reset. Next, at step 304, it is determined whether or not the throttle fully-closed switch 5b has been turned on. If the throttle full-close switch 5b is not on, the routine proceeds to step 305, where the target step position TST
Decrement EP by 1, then step 302 again
Wait until the flag F1 is set at When the target step position TSTEP is decremented by 1, ΔSTEP is determined to be negative in the drive control routine shown in FIG. 7, and the storage step position NSTEP is decremented by 1. As a result, the step motor 4 is rotated by one step in the direction in which the throttle valve 6 is closed.
At this time, the roller 28 of the arm 27 of the step motor 4
Is in contact with the throttle lever 25, the throttle valve 6 is rotated in the valve closing direction, but if not, the step motor 4 is simply rotated, and the step motor 4 is further rotated and the arm is rotated. After the 27 roller 28 comes into contact with the throttle lever 25, the closing operation of the throttle valve 6 is started.

When started closing operation of the throttle valve 6 is throttle opening becomes throttle reference opening P ₃ fully closed throttle switch 5b is turned on. As a result, proceeding from step 304 to step 306, the lower 3 bits of the target step position TSTEP
Is the reference step position ZSTEP, and then in step 307, the stored step position NSTEP and the target step position T
STEP is both set as the reference step position ZSTEP. That is, the stored step position NSTEP, the target step position TSTEP, and the actual step position of the step motor 4 are matched. The electronic control circuit 20 outputs opening information based on the throttle reference opening, and the target step position TSTEP is set based on the opening information. Next, the rotation of the step motor 4 is controlled so that the stored step position NSTEP becomes the target step position TSTEP, and thus the throttle valve 6 is controlled to the opening determined by the opening information of the electronic control circuit 20. If the actual step position of the step motor 4 and the stored step position NSTEP deviate for some reason, the actual step position, the stored step position NSTEP, and the target step position TSTEP are again matched at the next engine start.

〔The invention's effect〕

Even if an accelerator link for urging the throttle valve in the closing direction when the accelerator pedal is released is provided for safety, the actual step position can be matched with the stored step position. Also, idling rotation speed control is possible.

[Brief description of the drawings]

FIG. 1 is a side sectional view of a throttle body having a throttle valve, FIG. 2 is a side view of FIG. 1, FIG. 3 is a diagram showing a relationship between a throttle opening and an accelerator depression amount, and FIG.
FIG. 5 is an overall view of an internal combustion engine, FIG. 5 is a diagram showing output signals of a throttle sensor, FIG. 6 is a drive control circuit diagram of a step motor, FIG. 7 is a flowchart for executing drive control of the step motor, FIG. 8 is a flowchart for calculating the target step position, and FIG. 9 is a flowchart for executing an initialization process for matching the actual step position with the target step position. 4 Step motor, 5 Throttle sensor, 5a Variable resistor, 5b Throttle fully closed switch, 6 Throttle valve, 25 Throttle lever, 34 Accel link.

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Nao Kitamura 1-1 1-1 Kyowa-cho, Obu-shi Aisan Industry Co., Ltd. (56) References JP-A-61-244845 (JP, A) JP-A Sho 55-123327 (JP, A) JP-A-62-135629 (JP, A) JP-A-62-96756 (JP, A)

Claims (1)

(57) [Claims] A step motor for opening and closing a throttle valve is provided, a step position to be taken by the step motor is stored in a memory, and the stored step position stored in the memory is directed to a target step position. In a throttle valve control device that gradually changes and changes the actual step position of the step motor in accordance with the change of the stored step position, a throttle reference opening slightly larger than the throttle valve fully closed position is detected. A throttle fully-closed switch, a throttle lever that rotates together with the throttle valve, and an accelerator link that is connected to the accelerator pedal and engages with the throttle lever to regulate the maximum opening of the throttle valve. When in the return position, A throttle valve control device in which the maximum opening of the throttle valve to be regulated is made larger than the throttle reference opening, and the target step position and the storage step position are matched when the throttle valve reaches the throttle reference opening. .