JPH04301154A - Engine control device - Google Patents

Abstract

PURPOSE:To avoid engine stop at the working time of an ABS by detecting working condition of a solenoid valve of the ABS (anti-skid brake system), and making the ABS control the engine speed so as to be increased at the working time of that solenoid valve. CONSTITUTION:When slip ratio of a tire and the road surface exceeds a predetermined value at the working time of a brake, an ABS 5 operates a solenoid valve automatically to switch the pressure condition of a brake oil pressure route. In this case, a throttle open degree detecting means 1 for detecting the opening/closing condition of a throttle valve is provided. An engine speed control means 3 for changing condition of the air-fuel mixture to be supplied to a combustion chamber by an engine speed changing means 2 at the time of closing the throttle valve to control the engine speed at an optimum value is provided. When working condition of the solenoid of the ABS 5 is detected, the ABS 5 controls the engine speed so as to be increased by a predetermined quantity in comparison with the no-working time.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to an engine control device for an automobile equipped with an anti-skid brake system.
In particular, the present invention relates to an engine control device that prevents the engine from stopping even when a solenoid valve of an anti-skid brake system is activated.

0002

2. Description of the Related Art In automobile gasoline engines, the engine speed is controlled by changing the amount of air supplied to the combustion chamber and the mixing ratio of air and gasoline (air-fuel ratio). There are various methods for changing the amount of air and the air-fuel ratio, but the amount of air is usually determined by the opening degree of a throttle valve in conjunction with the accelerator pedal. The air-fuel ratio may be changed according to the amount of air supplied by the structure of the carburetor, or the amount may be electrically controlled by a fuel injection device.

[0003] When the accelerator pedal is released, the opening degree of the throttle valve is the smallest and the amount of intake air is most restricted. This situation occurs when the brake is applied to decelerate and when the vehicle is stopped. When the accelerator pedal is released and the clutch is disengaged, this is usually called the idle state, and the engine is rotating disconnected from the wheels. Keeping the engine speed at idle as low as possible will reduce fuel consumption and improve fuel efficiency, but if the engine speed is lowered too much, the engine will stall.

[0004] Controlling the air amount and air-fuel ratio during idling as described above requires delicate control, and since it is difficult to make precise adjustments when controlling the air amount using the throttle valve, it is difficult to make precise adjustments when the throttle valve opening is at its minimum. Sometimes it is common to have a separate air supply route in operation. FIG. 5 shows the basic structure of the air supply path and fuel vaporization section in a conventional carburetor.

FIG. 5(a) shows a normal running state, and FIG. 5(b) shows a normal running state.
) indicates the throttle valve is closed. At the time of (b), the throttle valve path is closed and the idle bypass path 76b becomes effective. Even in systems that use fuel injection, air is supplied from a separate idle bypass when the throttle valve is closed. In any case, when the accelerator pedal is released, the optimum rotational speed is maintained to reduce fuel consumption as much as possible and prevent the engine from stopping, and these controls are generally performed electrically.

[0006] When you step on the brake, the tire stops rotating,
The friction with the road surface causes the vehicle to stop, but when the slip ratio between the tires and the road surface exceeds a predetermined value, the coefficient of friction between the tires and the road surface decreases, conversely worsening braking. Therefore, the possibility of wheel locking is determined based on the rotational speed of the wheels and the condition of the brakes, and the brake pressure is reduced as necessary to obtain optimal braking. This is called an anti-skid brake system, hereinafter abbreviated as ABS.

FIG. 6 shows the configuration of the ABS. In FIG. 6, 85c to 88c are the brake parts, and the brake pedal 8
1c, pressure is applied to sandwich the brake disc by hydraulic pressure. 89c is the ABS control unit and the speed sensor 61
The possibility of wheel lock is determined from the wheel rotation sensor 62c and the wheel rotation sensor 62c, and the solenoid valves 82c to 84c are driven to control the necessary brake pressure.

The structure of the solenoid valves 82c to 84c is shown in FIG. 6(b), and the coil 91c
By applying current to the valve, the valve moves up and down, releasing pressure to the reservoir and reducing the pressure.

[0009]

[Problem to be Solved by the Invention] The current flowing through the coil 91c to drive the above-mentioned solenoid valve is a fairly large current. As a result, the voltage of the battery temporarily drops, causing the engine-driven alternator to operate, increasing the load on the engine. The ABS solenoid valve operates when the brakes are operated, and at this time, the accelerator pedal is naturally released and the throttle valve is closed. As mentioned above, when the throttle valve is closed, the engine speed is kept low to reduce fuel consumption as much as possible.
Therefore, if the engine load suddenly increases due to the activation of ABS, a problem arises in that the engine stops.

The present invention has been made in view of the above-mentioned problems, and it is an object of the present invention to realize an engine control device that prevents the engine from stopping even when the ABS is activated.

[0011]

[Means for Solving the Problems] In order to solve the above problems, the engine control device of the present invention detects the operation of a solenoid valve of an anti-skid brake system, and increases the engine rotation speed when the solenoid valve operates. do it like this. FIG. 1 is a diagram showing the basic configuration of an engine control device according to the present invention. In the drawings, parts having the same functions are designated by the same numbers, and from FIG. 2 onwards are indicated by lowercase letters.

That is, the engine control device of the present invention provides an anti-skid brake that automatically switches the pressure state of the brake hydraulic pressure path by operating a solenoid valve when the slip ratio between the tires and the road surface exceeds a predetermined value during brake operation. An engine control device for an automobile comprising a system 5, a throttle opening detecting means 1 for detecting the opening/closing status of a throttle valve, and a throttle opening detecting means 1 for detecting the opening/closing status of a throttle valve; An engine control device comprising an engine speed changing means 2 for changing the engine speed, and an engine speed controlling means 3 for controlling the engine speed changing means 2 so that the engine speed becomes optimal when the throttle valve is closed. , comprising a solenoid operation detection means 4 for detecting the operating state of the solenoid valve of the anti-skid brake system 5, and the engine speed control means 3 controls the engine speed to a specified value when the solenoid valve is in the operating state compared to when it is not in the operating state. This engine control device is characterized in that it controls the engine rotation speed changing means 2 so as to increase the engine rotation speed by a fixed amount.

[0013]

[Operation] When braking is started, the accelerator pedal is released, so the throttle valve is in its most closed state. Since the throttle opening detection means 1 detects this and outputs a signal, the engine rotation speed control means 3
In this state, the engine speed changing means 2 is controlled to adjust the air amount and air-fuel ratio so that the engine speed becomes optimal. If the ABS determines that it is necessary to reduce the brake pressure, the solenoid valve is operated, and at this time, the solenoid operation detection means 4 detects this operation and outputs a signal to the engine rotation speed control means 3. In response to this signal, the engine speed control means 3 controls the engine speed changing means 2 to increase the engine speed.
Even if the engine speed increases and engine load occurs due to the operation of the alternator, the engine will not stop.

[0014]

[Example] Various methods are used to control the air amount and air-fuel ratio, including the structure shown in Fig. 5, but in recent years, fuel injection Since there are many systems in which a device (injector) is provided to control the air amount and air-fuel ratio separately, the configuration of an embodiment in which the present invention is applied to this system is shown in FIG.

In the device shown in FIG. 2, a microcomputer 31a controls the entire engine, and
The control amount is calculated based on the data necessary for controlling the various sensors 6a, etc., and necessary control is performed. Naturally, this also includes control of the fuel injection amount. As shown in FIG. 2, whether the throttle valve 71a is closed is detected by the idle contact 1a. The operating status of the solenoid valve is sent from the ABS electronic control unit (ECU) 51a to the solenoid status port 41a.

Electronic engine control device (EC for engine)
In U), when the idle contact is closed, the air control valve 72a is adjusted via the vacuum switching valve 73a to control the amount of air passing through the bypass path, thereby controlling the engine speed. Naturally, the fuel injection amount is also controlled, but since it is easier to control the air amount, it is common to keep the fuel injection amount at a minimum and control the rotational speed using the air amount.

FIG. 3 shows a processing procedure in the apparatus shown in FIG. FIG. 3 also shows related parts of the ABS ECU. The ABS ECU performs ABS processing, and in step 100 determines whether a brake pressure reduction operation is necessary, and in steps 101 and 103 outputs a signal for solenoid valve operation depending on whether or not it is necessary. In the present invention, after steps 101 and 103, the operating state of the solenoid valve is written to the solenoid status port (SSP) in steps 102 and 104. Although the ABS ECU has written the operating state in the SSP here, it is of course possible to provide a separate sensor to detect the operating state of the solenoid valve.

[0018] Also, taking into consideration the engine speed response, steps 103 and 104 are swapped, so that when ABS pressure reduction operation is required, first write in SSP that the solenoid valve will be operated, and then Sometimes it is better to let the valve work. The engine ECU detects the output of each sensor in step 110, and determines in step 111 whether an idle signal is being output, that is, whether the throttle valve is closed. If there is no idle signal, other processing not directly related to the present invention is started. If the idle signal is output, a control value is calculated based on a predetermined relationship using data such as the engine rotational speed and traveling speed detected in step 110. This control value includes the opening degree BO0 of the basic bypass path, that is, the vacuum switching valve 73.
It also includes the control amount.

Next, in step 113, the value of SSP is read, and in step 114, a determination is made. If SSP is zero, the solenoid valve is not operating, so the value BO0 calculated in step 112 is used as the opening degree B of the bypass path.
Let it be O. If SSP is 1, BO0 is increased by a predetermined percentage and set as BO. Then, the vacuum switching valve 73a is controlled based on the value of BO.

[0020] A large current flows through the solenoid valve when it starts operating, and the operation ends in a short time, so the generator does not need to operate for a long time, so the processing procedure of the embodiment is such that the engine speed is increased only at this time. is shown in Figure 4. In this embodiment, when the solenoid valve starts operating, the engine speed is increased by a predetermined amount, and as time passes, the increased amount is decreased to return to the basic value. First, initialization is performed in step 120. At this time, a flag called ABSISC is provided and this flag is initialized.

The flag ABSISC becomes 1 when the solenoid valve is operated for the first time, and returns to 0 when the opening degree of the bypass path decreases to the basic value. Steps up to step 123 are the same as in FIG. 3, and step 124
It is determined whether the flag ABSISC is 1 or not. If the solenoid valve has already operated and the opening degree of the bypass path is in the process of decreasing from the increased value, the flag is 1 and the process proceeds to step 130. Otherwise, the process advances to step 125 to read the SSP and make a determination. If SSP is 1, it means that the solenoid valve has operated for the first time.
In step 127, the bypass route is increased by a predetermined percentage, and in step 128, ABSISC is set to 1. If S
If SP is 0, go to step 129 and change BO0 to B.
Let it be O.

In step 130, it is determined whether the opening degree becomes smaller than the basic opening degree BO0 when the opening degree is further decreased from the current opening degree BO. If it is still larger than BO0, the opening degree BO is decreased by a predetermined amount. If it is smaller than BO0, set the opening BO to BO0 and ABSIS
C is set to zero and a flag is set to indicate that the reduction process has ended. Then, in step 134, the bypass path is opened.
control based on

[0023] Here, the rate at which the engine rotational speed is increased and the process at which it is decreased can be considered in various ways depending on the engine. For example, it is possible to determine the optimal increase and decrease pattern and memorize it and change it according to that pattern, increase the rotation speed and then decrease it after a certain period of time has passed, or change it according to time. Instead, it is a method that changes it according to the number of rotations of the engine.

[0024]

According to the present invention, an engine control device that does not stop the engine even if the solenoid valve operates can be realized in a vehicle having an anti-skid brake system that adjusts the brake pressure using a solenoid valve.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the basic configuration of an engine control device of the present invention.

FIG. 2 is a diagram showing the configuration of an embodiment in which the engine rotational speed is controlled by controlling the amount of air passing through a bypass path when a slot valve is closed.

[Figure 3] ABS ECU and engine E in the device shown in Figure 2
It is a flowchart which shows the processing procedure in CU.

FIG. 4 is a flowchart showing a processing procedure in an embodiment in which the engine speed, which has been increased once, is gradually lowered by the apparatus shown in FIG. 2;

[Figure 5] When the throttle is closed in the carburetor,
It is an explanatory view when separate bypass paths are provided for air and fuel.

[Figure 6] Anti-skid brake system (ABS)
FIG.

[Explanation of symbols]

1...Throttle opening detection means 2...Engine speed changing means 3...Engine speed control means 4... Solenoid operation detection means

Claims (1)

[Claims] Claim 1: An automobile equipped with an anti-skid brake system (5) that automatically switches the pressure state of the brake hydraulic pressure path by operating a solenoid valve when the slip ratio between the tires and the road surface exceeds a predetermined value during brake operation. The engine control device includes a throttle opening detection means (1) for detecting the opening/closing status of a throttle valve, and when the throttle valve is closed, changes the state of the air-fuel mixture sent into the combustion chamber to determine the engine rotational speed. an engine speed changing means (2) for changing the engine speed; and an engine speed control means (3) for controlling the engine speed changing means (2) so that the engine speed becomes optimal when the throttle valve is closed. ), the engine control device includes a solenoid operation detection means (4) for detecting the operation state of the solenoid valve of the anti-skid brake system (5), and the engine rotation speed control means (3) is configured to detect the operation state of the solenoid valve of the anti-skid brake system (5). An engine control device characterized in that when the engine is in the operating state, the engine rotational speed changing means (2) is controlled so as to increase the engine rotational speed by a predetermined amount compared to when it is not in the operating state.