JPH0359254B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a throttle valve control device for an engine, and more particularly, to an engine throttle valve control device that electrically controls the throttle valve opening in order to obtain a predetermined intake air amount for an accelerator operation amount that indicates a required engine output. Concerning things that can be controlled.

(Prior Art) Conventionally, as a technology for controlling the amount of air supplied to the engine to a predetermined intake amount in response to the amount of accelerator operation indicating the required engine output, as shown in Japanese Patent Application Laid-Open No. 51-138235, an accelerator detection means for detecting the amount of operation; a target air amount setting means for receiving the output of the accelerator detection means and setting a target value of air to be supplied to the engine according to the amount of accelerator operation; and the target air amount setting means. and a throttle valve driving means that receives the output and drives the throttle valve to set the air amount to the target value, and adjusts the target air amount (that is, the target throttle valve opening) according to the accelerator operation amount.
A system is known in which the opening degree of the throttle valve is feedback-controlled to obtain the target air amount. Then, the air-fuel ratio of the engine is set to the target value by supplying the fuel amount to the engine so that the air-fuel ratio is set in advance according to the intake air amount based on the throttle valve opening degree. .

(Problem to be Solved by the Invention) By the way, in an engine in which the throttle valve is mechanically linked to the accelerator pedal as usual, the intake air amount characteristic with respect to the accelerator operation amount varies depending on the engine rotational speed, as shown in FIG. The lower the engine speed, the lower the maximum amount of intake air, and the point in time when this maximum value is reached is the point at which the lower the engine speed, the smaller the accelerator operation amount. For this reason, for example, when the accelerator operation amount is increased from a low engine speed range in order to accelerate suddenly, the intake air amount is reduced by the engine speed at the beginning of the acceleration due to the delay in increasing the engine speed relative to the increase in the accelerator operation amount. The maximum value is immediately reached at low revolutions, and after that, the intake air volume does not increase until the engine revolutions increase regardless of the increase in the amount of accelerator operation, resulting in a delay in the increase in output and a decrease in acceleration feeling. was.

The present invention has been made in view of the above, and its purpose is to provide an engine in which the throttle valve opening is electrically controlled in response to the amount of accelerator operation, as described above, at various engine speeds. To continuously increase and change the intake air amount characteristic with respect to the amount of accelerator operation in accordance with the increasing change in the amount of accelerator operation so that the maximum value is reached at almost the full amount of accelerator operation (for example, see Fig. 8).
This allows the increase in intake air volume to respond favorably to increases in accelerator operation even in the low engine speed range.
The purpose is to improve the accuracy of controlling the intake air amount regardless of the engine speed.

(Means for solving the problem) In order to achieve the above object, the solving means of the present invention, as shown in FIG. An engine rotation speed detection means 22 is provided,
For both the detection means 16 and 22, the detection means 1
6 and 22, the target value of the air to be supplied to the engine is determined by the maximum intake amount determined by the engine speed at that time, which becomes the target air amount when the accelerator is fully operated, and as the accelerator operation decreases. Therefore, the target intake air amount setting means 30 is set based on the accelerator operation amount-target intake air amount characteristic in which the target air amount decreases, and the throttle is adjusted to set the intake air amount to the target value in response to the output of the target intake air amount setting means 30. This configuration includes a throttle valve driving means 31 for driving the valve.

(Function) With the above configuration, in the present invention, the throttle valve opening is adjusted such that even at the same engine speed, the intake air amount does not reach the maximum early as the accelerator operation amount increases, but gradually increases until the accelerator operation amount is full. By controlling this, the increase in intake air volume responds favorably to increases in accelerator operation even in the low engine speed range, improving the control accuracy of intake air volume regardless of engine speed. .

(Example) Hereinafter, an example of the present invention will be described based on the drawings from FIG. 2 onwards.

FIG. 2 shows the overall configuration of an engine control device according to an embodiment of the present invention, in which 1 is a four-cylinder engine, for example, and 2 is an engine with one end opening to the atmosphere via an air cleaner 3 and the other end opening to the engine 1. An intake passage 4 supplies intake air (air) to the engine 1, and an exhaust passage 4 has one end open to the engine 1 and the other end opened to the atmosphere to discharge exhaust gas from the engine 1. Reference numeral 5 denotes an accelerator pedal that is depressed in response to engine output requirements, and 6 a throttle valve that is disposed in the intake passage 2 and controls the amount of intake air. There is no linkage relationship, and as will be described later, it is electrically controlled by the amount of depression of the accelerator pedal 5, that is, the amount of accelerator operation. Reference numeral 7 denotes a throttle actuator consisting of a step motor or the like that opens and closes the throttle valve 6. Reference numeral 8 denotes a catalyst device which is interposed in the exhaust passage 4 and purifies exhaust gas.

Reference numeral 9 denotes a fuel injection valve disposed downstream of the throttle valve 6 in the intake passage 2 to inject and supply fuel. The fuel tank 13 is connected to the fuel tank 13 through the fuel tank 13, and the fuel is supplied from the fuel tank 13, and the surplus fuel is returned to the fuel tank 13 through a return passage 15 with a fuel pressure regulator 14 interposed therebetween. Therefore, the fuel is supplied to the fuel injection valve 9 at a predetermined pressure.

In addition, 16 is an accelerator pedal position sensor as an accelerator detection means for detecting the amount of depression of the accelerator pedal 5, that is, the accelerator operation amount θ _ACC , and 17 is disposed upstream of the throttle valve 6 in the intake passage 2 to detect the amount of intake air. air flow meter to detect,
Reference numeral 18 denotes an intake temperature sensor which is also arranged upstream of the throttle valve 6 in the intake passage 2 and detects the intake air temperature;
19 is a throttle position sensor that detects the opening degree of the throttle valve 6; 20 is a water temperature sensor that detects the temperature of engine cooling water;
The detection signal 20 is input to a control unit 21 consisting of an analog computer, etc.
The control unit 21 controls the throttle actuator 7 and the fuel injection valve 9. Furthermore, an igniter 22 is input connected to the control unit 21, and receives a signal indicating the number of ignitions, that is, the engine rotational speed Ne. Further, a duplexer 23 and a battery 24 are connected as inputs to the control unit 21, and input signals of ignition timing and battery voltage, respectively.

The control unit 21, as shown in FIG.
27, a RAM 28, and a throttle actuator drive circuit 29 for driving the throttle actuator 7 in forward or reverse rotation. the above
As shown in FIG. 6, the ROM 27 stores in advance a target intake air amount map that three-dimensionally depicts the accelerator operation amount - target intake air amount characteristic according to the engine speed, and each accelerator operation amount - target intake air amount map is stored in advance. The intake air volume characteristics are calculated at the full accelerator operation amount (at the accelerator depression angle).
70°), the maximum intake amount determined by the engine speed at that time is set so that it decreases as the engine speed decreases.
Further, the target air amount is set to gradually decrease from the maximum value as the accelerator operation amount decreases. Similarly, as shown in FIG. 7, the ROM 27 contains the engine speed and
A target throttle valve opening degree map that increases in accordance with the target filling amount per revolution is stored.

Further, as shown in FIG. 4, the CPU 26 has the following functions:
Comprising a first calculation unit 26a and a second calculation unit 26b,
The first calculation unit 26a calculates the target intake air amount Qa _OBJ from the target air intake amount map shown in FIG _. The second calculation unit 2
6b is the target intake air amount from the first calculation unit 26a.
Qa Engine speed Ne from _OBJ and igniter 27
The target throttle valve opening _THOBJ is calculated from the target throttle valve opening map shown in FIG. 7 based on the signal.

Next, specific operations of the first and second calculation sections 26a and 26b of the CPU 26 and control of the throttle actuator drive circuit 29 will be explained based on the flowcharts of FIGS. 5A and 5B. After starting and initializing in step _S1 , the accelerator operation amount θ _ACC from the accelerator pedal position sensor 16 is determined in step _S2 .
Engine speed Ne from signal and igniter 27
Based on the signal, the target intake air amount Qa _OBJ is determined from the target intake air amount map shown in FIG.

Next, in step _S3 , the target intake air amount Qa _OBJ obtained in step _S2 is divided _by the engine rotational speed Ne to obtain the target filling amount Q _AVC per engine revolution, and then in step _S4 The target throttle valve opening _THOBJ is determined from the target throttle valve opening map shown in FIG. 7 based on the target charging amount Q _AVC and the engine Ne determined in Step _S2 .

Then, a time interrupt is made in the middle of the repetition of steps _S2 to _S4 , and after inputting the actual throttle valve opening THR signal from the throttle position sensor 19 at step _SA , the actual throttle valve opening _THR signal is input from the throttle position sensor 19 at step _SB . The valve opening TH _R and the target throttle valve opening TH _OBJ are compared in magnitude, and if TH _R < TH _OBJ , the throttle actuator drive circuit 29 is commanded to rotate in the throttle valve opening direction in step S _C. On the other hand, if TH _R >TH _OJB is NO, the throttle actuator drive circuit 29 is commanded to rotate in the throttle valve closing direction at step S _D , and the process returns.

Therefore, in the operation flow of the control unit 21, in step _S2 , the outputs of the accelerator position sensor 16 and the igniter 22 are received, and the target value of air to be supplied to the engine is determined based on the engine speed at that time. The maximum intake amount becomes the target intake amount when the accelerator is fully operated,
Target intake air amount setting means 30 configured to set the target intake air amount based on an accelerator operation amount-target intake air amount characteristic in which the target intake air amount decreases as the accelerator operation amount decreases.
It consists of Also, by steps S _A to _{S D} ,
A throttle valve driving means 31 is configured to receive the output of the target intake air amount setting means 30 and drive the throttle valve 6 so that its opening becomes the target throttle valve opening TH _OBJ in order to set the intake amount to the target value. are doing.

Therefore, in the above embodiment, for the accelerator operation amount-target intake amount characteristic at each engine speed in the target intake air amount map shown in FIG. 6, the maximum intake amount determined by the engine speed at that time is is the target intake air amount when the accelerator operation amount is full, and the target intake air amount is given a characteristic that gradually decreases as the accelerator operation amount decreases, and the accelerator operation amount -
Since the target intake air amount at a predetermined engine speed and a predetermined accelerator operation amount is set based on the target intake air amount characteristics, as shown in FIG.
Regardless of the engine speed, the target intake air amount gradually increases without reaching the maximum value determined by the engine speed at that time, and responds well to an increase in the amount of accelerator operation. As a result, the engine output increases smoothly in accordance with the increase in the amount of accelerator operation, resulting in a good acceleration feeling. Therefore, it is possible to improve the control accuracy of the intake air amount with respect to the accelerator operation amount, and in turn, it is possible to improve the acceleration feeling.

(Effects of the Invention) As explained above, according to the present invention, the amount of air supplied to the engine is gradually increased in accordance with the increase in the amount of accelerator operation even when accelerating from a low engine speed range, and Since the engine is designed to respond well to increases in the amount of operation, the accuracy of controlling the intake air amount relative to the amount of accelerator operation regardless of the engine speed can be improved, and in turn, the engine output can be smoothly increased to improve acceleration feeling. It is something that can be done.

[Brief explanation of drawings]

Figure 1 is a block diagram showing the configuration of the present invention, Figure 2 is a block diagram showing the configuration of the present invention.
8 to 8 show embodiments of the present invention, FIG. 2 is a general schematic diagram, FIG. 3 is a diagram showing the internal configuration of the control unit, FIG. 4 is a diagram showing the internal configuration of the CPU, and FIG. 5 is a diagram showing the internal configuration of the CPU. Figures A and B are flowcharts for explaining the operation of the control unit, Figure 6 is a diagram showing the target intake air amount map stored in the ROM, and Figure 7 is a diagram showing the target throttle valve opening map. , FIG. 8 is a characteristic diagram of the intake air amount with respect to the accelerator operation amount, showing the characteristics of the present invention. 9th
The figure shows the intake air amount characteristics with respect to the accelerator operation amount in an engine in which the throttle valve is mechanically linked to the accelerator pedal. 1...engine, 5...accelerator pedal, 6...
... Throttle valve, 7... Throttle actuator, 16... Accelerator pedal position sensor,
22...Igniter, 30...Target intake air amount setting means, 31...Throttle valve driving means.

Claims (1)

[Claims] 1. An accelerator detection means for detecting the amount of accelerator operation, an engine rotation speed detection means for detecting the engine rotation speed, and a target value of air to be supplied to the engine based on the outputs of the accelerator detection means and the engine rotation speed detection means, The maximum intake amount determined by the engine speed at that time becomes the target intake amount when the accelerator is fully operated, and the target intake amount decreases as the accelerator operation amount decreases.
a target air amount setting means that is set based on the target intake air amount characteristics; and receiving an output of the target air amount setting means;
1. A throttle valve control device for an engine, comprising a throttle valve drive means for driving a throttle valve to set an air amount to a target value.