JPH01104944A - Controller for quantity adjusting valve - Google Patents

Abstract

PURPOSE:To obtain the always stable traveling characteristic by adjusting a quantity adjusting valve so that the opening degree at that time is kept when the second signal which represents the variation portion of the first signal on the basis of the operation quantity of an accelerator is within a prescribed value and by controlling the quantity adjusting valve according to the first signal when the second signal exceeds a prescribed value. CONSTITUTION:A butterfly type quantity adjusting valve 1 installed in the intake system of an engine is rotatably supported by a shaft 2 and urged in the closing direction by a return spring 3. Further, a stepping motor 5 is jointed with the shaft 2 through a joint 4, and drive-controlled by a control circuit 10 into which each output signal of an opening degree sensor 6 and an operation quantity sensor 8 for detecting the operation quantity of an accelerating pedal is inputted. In this case, in the control circuit 10, the second signal which represents the variation portion of the first signal on the basis of the accelerator operation quantity is compared with a prescribed value, and when the second signal is within a prescribed value, the quantity adjusting valve 1 is controlled so as to be kept at the opening degree at that time. While, when the second signal exceeds a prescribed value, the quantity adjusting valve 1 is controlled according to the first signal.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is an adjustment method that uses a motor to control the #A amount valve (throttle valve), such as a butterfly type, for adjusting the amount of intake air provided in the intake system of an engine. The present invention relates to a control device for a quantity valve.

[Conventional technology]

Conventionally, a device in which a step motor or a DC motor is connected to a butterfly-type metering valve (so-called throttle valve) of an engine, and this motor is driven in accordance with the operation of an automobile's accelerator pedal is disclosed in, for example, JP-A-51-138235. It has been proposed in the Publication No.

This device has the advantage that the link mechanism connecting the accelerator pedal and the metering valve can be eliminated, and that automatic driving systems such as vehicle speed maintenance and automatic start and warm-up can be easily incorporated.

[Problem to be solved by the invention]

However, in the conventional configuration, the voltage signal corresponding to the amount of accelerator depression is simply compared with the voltage signal corresponding to the opening degree of the metering valve.
Since the motor is controlled so that the two always match, the metering valve is also driven by the motor in response to a slight change in the amount of accelerator depression.

Therefore, even if the driver tries to keep the amount of accelerator depression constant and drive the vehicle at a constant speed, the vibration applied to the vehicle causes the accelerator depression 1 to vibrate with slight fluctuations regardless of the driver's intention. become. Then, the 'Jffi valve is moved by the motor in response to the fluctuation, making it impossible to properly adjust the speed of the vehicle to a desired state. In some cases, acceleration and deceleration may be repeated periodically, resulting in extremely poor drivability and extreme discomfort for the driver.

That is, with the conventional configuration, stable running characteristics could not be obtained.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a control device for a metering valve for adjusting the intake air amount of a vehicle engine, which can provide stable running characteristics and improve riding comfort.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides an adjustment method in which an imi valve for adjusting the intake air amount of an engine mounted on a vehicle is controlled by a motor according to the amount of operation of the accelerator. The valve control device is configured to maintain the metering valve at the current opening degree when a second signal indicating a variation in the first signal based on the accelerator operation amount is within a predetermined value. A control device for a metering valve, characterized in that the motor is controlled so that when the second signal exceeds a predetermined value, the metering valve is driven in accordance with the first signal. It is said that

〔Example〕

The present invention will be explained below with reference to embodiments shown in the drawings.

In FIG. 1, reference numeral 1 denotes a butterfly-type metering valve provided in the intake system of the engine, which is rotatably supported by a shaft 2. As shown in FIG. A return spring 3 made of a torsion coil spring is attached to the shaft 2, and the metering valve 1 is biased in the fully closed direction by the return spring 3.

A step motor 5 is connected to one end of the shaft 2 via a joint 4 for driving the metering valve 1, and a step motor 5 is connected to the other end to detect the opening of the metering valve 1. An opening sensor 6 is coupled thereto.

The control circuit 10 is a circuit for controlling the step motor 5, and receives the output signal of the opening sensor 6 and the output signal of the operation amount sensor 8 that detects the operation amount of the accelerator pedal 7 of the automobile.

Next, the control circuit 10 will be explained with reference to FIG. Second
In the figure, this control circuit 10 schematically includes a direction determination circuit 20 for determining the driving direction of the step motor 5.
．． It is composed of an oscillation circuit 40 for determining the drive speed of the step motor 5 and a drive circuit 60 for controlling the excitation current of the step motor 5, and the opening sensor 6 and the operation amount sensor 8 are both composed of potentiometers. is shown as a variable resistor.

The direction determination circuit 20 includes resistors 21 to 35 . diode 36
and operational amplifier (hereinafter referred to as OP amplifier) 37.38.
39, the output voltage v of the manipulated variable sensor day
1 and the output voltage ■2 of the opening sensor 6 are input.

Here, the OP amplifier 37 operates as a differential amplifier,
A voltage proportional to the voltage difference (Vg-v, ).

Output. Further, the OP amplifier 38 operates as an absolute value differential amplifier, and the absolute value of the difference between the constant reference voltage V□ divided by the resistor 28.29 and the voltage v0 is +Vr, -V.
, + outputs a voltage V, (see Fig. 3). Further, a voltage (4) proportional to the voltage difference (V-tVo) is output to the drive circuit 60.

The oP amplifier 39 receives the fourth signal due to the action of the positive feedback resistor 35.
It operates as a comparator with the hysteresis characteristic shown in the figure, and outputs a level or O level signal depending on the input voltage v3.

The oscillation circuit 40 includes resistors 41 to 47 . Zener diode 48.49. Capacitor 50 and OP amplifier 51.52
The output voltage (2) of the manipulated variable sensor 8 is inputted thereto.

Here, the OP amplifier 51 operates as an inverting amplifier with a voltage limiter, and outputs a voltage 5 whose value decreases as the opening degree of the 5J11 valve 1 increases.

The OP amplifier 52 operates as a voltage controlled oscillator and outputs a pulse signal with a frequency proportional to the input voltage .

The drive circuit 60 includes transistors 61 to 65 . Resistance 66~
69. Diodes 71-74. Capacitor 75, 76 and step motor drive integrated circuit (hereinafter referred to as IC) 7
7 (for example, IC8771 manufactured by Sanyo Denki Co., Ltd.), the pulse signal of the oscillation circuit 40 is input to the clock terminal CL of the IC 77, and the up/down terminal U/
The voltage 4 of the direction determination circuit 20 is input to D.

By supplying the base current to the power transistors 62 to 65 from the output terminals Q and -Q4 of the IC77, the current to the excitation winding of the step motor 5 is sequentially interrupted, and a high voltage is applied to the terminal U/D. When a level signal is input, the step motor 5 is driven in the forward direction to increase the opening of the metering valve l, and when a low level signal is input to the terminal U/D, the step motor 5 is driven in the reverse direction. to reduce the opening degree of metering valve 1.

Furthermore, the driving speed and torque of the step motor 5 are as follows:
It changes depending on the pulse signal input to the terminal CL, and the lower the frequency of this pulse signal, the lower the speed and the higher the torque the step motor 5 is driven.

Note that a constant voltage of about 5 volts is applied to the control circuit 10 from a constant voltage circuit 81, and the output voltage of an on-vehicle battery 83 is input to the step motor 5 via a key switch 82.

The operation in the above configuration will be explained. When the driver of a car reduces the amount of depression of the accelerator pedal 7 from a certain steady state, the output voltage of the operation amount sensor 8 that detects this decreases ■1
decreases, and the output voltage of the OP amplifier 37 ■. is the reference voltage V
It becomes larger than rar.

Therefore, 1 v, , -v. The voltage 3 proportional to 1 is equal to or higher than the predetermined voltage 67 approximately determined by the resistor 31.32, and O
The output of the P amplifier 39 becomes low level and the transistor 6
1 is turned off, and the pulse signal of the oscillation circuit 40 is transmitted to the clock terminal CL.

On the other hand, OP7'38+7) output voltage Va is V
raf<vo, the signal becomes low, and this low level signal is input to the terminal U/D, causing the IC 77 to enter the down mode, rotating the step motor 5 in the opposite direction and reducing the opening degree of the 11-volume valve 1.

In this way, when the opening of the metering valve 10 becomes smaller, the output voltage V2 of the opening sensor 6 that detects this also becomes smaller, the output voltage v0 of the OP amplifier 37 becomes smaller again, and the reference voltage V
Approach raf. As a result, the voltage ■ changes to the predetermined voltage Δ■
When it becomes smaller, the OP amplifier 39 outputs a high level signal to turn on the transistor 61, and the clock terminal CL
The application of the pulse signal of the oscillation circuit 40 to the step motor 5 is stopped, and the step motor 5 is stopped at that position.

Furthermore, when the driver increases the amount of depression of the accelerator pedal 7 from this state, the output voltage vI of the operation amount sensor 8 increases, and the output voltage v0 of the OP amplifier 37 increases to the reference voltage Vr.
It becomes smaller than eef.

Therefore, the output voltage (3) of the OP amplifier 38 becomes equal to or higher than the predetermined voltage 67, and the output of the OP amplifier 39 becomes low level, turning off the transistor 61 and transmitting the pulse signal to the terminal C.
Let L input.

On the other hand, the output voltage ■ of the OP amplifier 38 is V, , f〉■
. Therefore, the high level signal is inputted to the terminal U/D, and the IC 77 enters the up mode, rotating the step motor 5 in the positive direction and increasing the opening degree of the metering valve 1.

When the opening of the metering valve 1 increases in this way, the output voltage v2 of the opening sensor 6 also increases, and the output voltage v0 of the OP amplifier 37 decreases again and approaches the reference voltage V rat. As a result, the OP amplifier 39 outputs a high level signal to turn on the transistor 61, and the step motor 5
stop at that position.

In this way, the opening degree of the 1lffi valve 1 corresponds to the operation amount of the accelerator pedal 7 on a one-to-one basis, but when increasing the opening degree of the metering valve 1 in the above operation, it is necessary to resist the spring force of the return spring 3. This will be done.

In this embodiment, when the accelerator pedal 7 is depressed and the output voltage (2) of the operation amount sensor 8 increases, the OP amplifier 51 of the oscillation circuit 40 detects this, and the voltage (2) increases.
Since the frequency of the pulse signal of the oscillation circuit 40 is lowered, even if the step motor 5 is small, the step motor 5 can be driven with sufficient torque to overcome the spring load.
The valve can be opened well.

Furthermore, when the accelerator pedal 7 is returned, it is necessary to promptly close the metering valve 1, but as in this case, when the accelerator pedal 7 is returned, the output voltage of the operation amount sensor 8 is
, becomes smaller, and as a result, the output voltage V of the OP amplifier 51
, increases, increasing the frequency of the pulse signal of the oscillation circuit 40, the driving speed of the step motor 5 increases, and the metering valve 1 is quickly closed. - Further, a voltage V proportional to l V-r Vol.

When is smaller than the predetermined voltage ΔV, the output of the OP amplifier 39 is at a high level and turns on the transistor 61, so that the pulse signal of the oscillation circuit 40 is applied to the clock terminal CL.
The step motor 5 is stopped at the current position, and the metering valve 1 is held at the current opening degree. In other words, I
'/-r As long as V (■, which is proportional to 11) does not exceed Δ■, that is, the deviation signal ■ between the output voltage V of the manipulated variable sensor 8 and the output voltage V2 of the opening sensor 6 is less than the predetermined value. As long as this is the case, the metering valve 1 is not driven to open or close by the step motor 5, and is maintained at the opening degree at that time.

Therefore, the output voltage ■1 of the operation amount sensor 8 is
UF4 unless the output voltage changes by more than a predetermined value with respect to the output voltage.
Since the amount valve 1 is held at the opening degree at that time, when the driver is keeping the amount of operation of the accelerator pedal 7 constant in order to drive the car at a constant speed, the accelerator may be pressed due to vibrations applied to the car. Even if the manipulated variable slightly fluctuates, if the fluctuation is within a predetermined range, the opening degree of the tJHE valve 1 will not change,
Therefore, it becomes easier to drive the vehicle at a predetermined speed, stable running characteristics are obtained, and ride comfort is significantly improved.

In the above embodiment, a potentiometer was used as the sensor 6.8, but a differential transformer, a strain gauge, etc. may also be used. Alternatively, a device may be used in which the opening degree of the metering valve 1 is stored using a large-scale integrated circuit (LSI), and the voltage or frequency changes according to this opening degree.

Further, in the above embodiment, the control circuit 10 is constructed of an analog type wired logic circuit, but it goes without saying that it can be constructed using a digital type or a digital stored program type microcomputer.

Further, although the pulse frequency of the oscillation circuit 40 is configured to be changed in accordance with the output signal of the manipulated variable sensor 8, it may be configured to be changed in accordance with the output signal of a sensor that corresponds to the spring force of the return spring, for example. The output signal of the opening sensor 6 may also be used.

〔Effect of the invention〕

As described above, according to the present invention, when the second signal indicating the variation of the first signal based on the accelerator operation amount is within a predetermined value, the opening degree of the metering valve at that time is maintained. Since the configuration is such that the step motor is controlled so that the metering valve is driven in accordance with the first signal when the second signal exceeds a predetermined value, minute fluctuations in accelerator operation,
In other words, the step motor is no longer driven due to unintentional fluctuations in the amount of accelerator operation by the driver, making it extremely easy to control the speed of the vehicle, providing stable driving characteristics, and improving ride comfort. It has the excellent effect of significantly improving performance.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram showing an embodiment of the present invention, FIG. 2 is an electric circuit diagram showing the control circuit shown in FIG. 1, and FIGS. 3 and 4 are graphs for explaining the operation. l... Metering valve, 3... Return spring, 5... Step motor, 6... Opening sensor, 7... Accelerator pedal, 8... Operation amount sensor, 10... Control circuit, 20・
. . . direction determination circuit, 40 . . . oscillation circuit, 60 . . . drive circuit, CL . . . clock terminal.

Claims (2)

[Claims] (1) A metering valve control device that uses a motor to control a metering valve for adjusting the intake air amount of an engine mounted on a vehicle in accordance with an accelerator operation amount, the first metering valve being controlled based on the accelerator operation amount. When the second signal indicating the variation of the signal is within a predetermined value, the motor is controlled so that the metering valve is held at the opening degree at that time, and when the second signal exceeds the predetermined value. A control device for a metering valve, characterized in that the motor is controlled so that the metering valve is driven in accordance with the first signal. (2) The metering according to claim 1, wherein the second signal is a signal that corresponds to a deviation between the first signal and a signal that corresponds to the opening degree of the metering valve. Valve control device.