JPS62225742A - Engine controller - Google Patents

Abstract

PURPOSE:To control the opening degree of a throttle valve with high precision by detecting the operation state of the driving device for an actuator which controls the opening of the throttle valve and feedback-transmitting the signal which is obtained by multiplying the detection signal by the correction coefficient into a controller. CONSTITUTION:The diaphragm 5 of an actuator 4 is shifted by the negative pressure in an intake pipe 2, and varies the opening degree of a throttle valve 1. While, the negative pressure in the intake pipe 2 is controlled by a driving device 8. A controller 11 inputs the electric current IR which flows in the case when a transistor 12 is ON, from an operation state detecting device 13. The correction coefficient K is obtained from the duty value and the inductance and resistance of a solenoid 10. The actual electric current IL which flows in the solenoid 10 is obtained by multiplying the input electric current IR by the correction coefficient K. The electric current IL is compared with the comparison electric current value, and the duty value is increased or reduced according to the comparison judgement. Therefore, the value of the electric current which flows in the driving device is corrected with high precision, and the opening degree of a throttle valve can be controlled with high precision.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an engine control device, and particularly to the above-described device that can control the opening of a throttle valve with high precision.

[Conventional technology]

The method of controlling the throttle valve opening and engine speed is to use a DC motor as an actuator to control the valve opening, or to displace a diaphragm using intake negative pressure and adjust the amount of displacement. Depending on the situation, there are methods of controlling the opening and closing of the valves. In this case, a drive device driven by duty control is provided in the negative pressure passage to control the amount of negative pressure. As examples of this type of device, the former method is disclosed in Japanese Patent Application Laid-open No. 56-20730, and the latter method is disclosed in Japanese Patent Application Laid-open No. 56-60835.

[Problem that the invention seeks to solve]

Regarding the above-mentioned conventional technology, especially the latter control method, there is no consideration given to the operating state of the drive device mentioned above, and even if an attempt is made to control the drive device with a constant control amount, the amount of operation changes. There was a problem.

An object of the present invention is to always obtain an optimum amount of operation regardless of the operating state of the drive device.

[Means for solving problems]

The above purpose is to detect the current flowing through the solenoid of the drive device through a transistor that is connected in series with the solenoid and switches it, and to multiply the detected current by a correction coefficient to determine the actual current flowing through the solenoid. This is achieved by calculating and feeding it back to the control device. That is, this detects the operating state of the drive,
This means that a signal obtained by multiplying the detection signal by a correction coefficient is fed back to the control device so that the actual amount of operation becomes the optimum value.

[Effect]

A detection signal for detecting the operating state of the drive device is fed back to the control device, and the drive device is controlled to obtain the optimum amount of motion by the control signal input from the control device. However, due to the influence of the back electromotive force on the control signal flowing to the solenoid in the drive device, the actual signal flowing to the solenoid no longer corresponds to the detection signal described above. Therefore, by multiplying the detection signal by a correction coefficient, this problem is solved, and the amount of operation of the drive device can be controlled at an optimum amount regardless of the state of the drive device.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG.

An intake pipe 2 of the engine 7 is communicated with an actuator 4 through a passage 3, and a diaphragm 5 of the actuator 4 is displaced by negative pressure within the intake pipe 2.

This displacement is transmitted in conjunction with the movement of the rod 6 of the actuator 4 as a change in the opening degree of the throttle valve 1. The negative pressure in the intake pipe 2 supplied to the actuator 4 is a driving device! 8 (hereinafter referred to as VCM). The VCM is comprised of a valve 9 and a solenoid 10, and the solenoid 10 drives a transistor 12 in response to a signal issued from a control device 11 to perform ON-OFF duty control.

The operating state detection device [13 detects the current flowing through the solenoid 10, and this detection signal is fed back to the control device 11, which controls the opening degree of the throttle valve 1 so that the engine rotation speed becomes a predetermined value. . On the other hand, in order to detect the operating state of the engine 7, a rotational speed signal from an engine rotational speed detector 14 and a signal from a load detection device 15 that detects the engine load are input to the control device 11.

This system detects the current value flowing through the solenoid 10 of the drive device 8 and feeds this detection signal back to the control device 5tll to keep the opening of the throttle valve 1 stable and control the engine rotational speed at idle. be. However, the current value flowing through the solenoid 1o (in this case, the current value refers to the average value of the 0N-OFF current flowing through the solenoid 10) is caused by the back electromotive force generated in the solenoid 10, and the current value flows through the resistor R of the operating state detection device [13]. Different from electric current. Figure 2 shows the drive circuit 8 and control device 11 in Figure 1.
, is a diagram showing a series circuit of the solenoid 10.1, the transistor 12, and the resistor R in the operating state detection device 13, and FIG. It is a figure showing a waveform (hatched part). Now, when the transistor 12 is turned on, a current Itt flows during that period, but the current flow is caused by the above-mentioned back electromotive force in the solenoid 10, and the average current has a relationship of Itt>I n.

On the other hand, the engine speed is 0N-O when the transistor 12 is set to 0N-O.
It is known that there is a proportional relationship with the duty value for FF operation. Further, the relationship between the above-mentioned duty value and M is as shown in FIG.

In the figure, A is a current flowing through the solenoid 10, and B is a current detected by the emitter circuit of the transistor 12. Therefore, in the configuration shown in FIG. 1, the current It flowing through the solenoid 10 is actually detected as IR and fed back to the control device N11, so that the desired throttle valve opening or desired It becomes impossible to obtain engine speed.

Therefore, the above-mentioned IR is corrected by the method described below. FIG. 5 is a flowchart illustrating the above correction method. In FIGS. 1 and 5, the IR is taken in from the operating state detection device 13 (step 16), and its output is input to the control circuit 11. In the control circuit 11, calculation is performed to obtain a correction coefficient K from the current duty value (D) (step 17), and the correction coefficient is a function of the duty D with the inductance of the solenoid 10 and the solenoid resistance R as a constant. It can be expressed by the following relational expression.

K=f (D, L, R) The result of the calculation based on this function is stored in the storage circuit of the control circuit U as a table, for example. Next, the above calculation result is obtained by calculating the current IR taken in at step 16 as follows, and the actual current It flowing through the solenoid 10,
(Step 18).

It, = I *
The value is increased or decreased (step 20.21).

As described above, the current value flowing through the drive device 8 is determined by the actual current value (engineering) flowing through the solenoid of the drive device, especially when performing duty control, and the current value (IR) flowing on the circuit connected in series with the solenoid. ), the correction method of the present invention makes it possible to correct with high accuracy the slight deviation that occurred even when controlling the opening of the throttle valve in the past, and the opening of the throttle valve In other words, engine speed control can now be performed with high precision. Furthermore, since the above-mentioned correction coefficient can be determined theoretically if the circuit constant of the solenoid is known, it goes without saying that the correction result will be highly accurate. Furthermore, the method of the present invention is not limited to simply controlling the opening of an engine throttle valve, but is also a duty control system that detects the current flowing through a solenoid and feeds back the detected current to the control system. It is available.

〔Effect of the invention〕

As described above, according to the present invention, regardless of the state of the drive device,
Since the operating amount can be optimally controlled, a stable and optimal throttle valve opening can always be obtained.

[Brief explanation of drawings]

Fig. 1 is a block diagram of the present invention, Figs. 2.3.4 are explanatory diagrams of the present invention, and Fig. 2 is a flowchart of the present invention. 8... Drive device, 10... Solenoid, 11...
Control device, 13... operating state detection device.

Claims (1)

[Claims] 1. An actuator that controls opening of the throttle valve, a drive device that drives the actuator, an operation state detection device that detects the operating state of the drive device, and a detection signal of the operation state detection device that is inputted to drive the above-described drive. and a control device for controlling the device, the detection signal detected by the operating state detection device is calculated by combining an element constant determined from an electrical element of the driving device and a current operating state value of the driving device. The first step is to calculate a correction coefficient determined as a function.
An engine control device comprising: a calculation means; and a second calculation means for calculating the calculated correction coefficient and the detection signal.