JPH0248727B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fuel injection device for an internal combustion engine for controlling an air-fuel ratio to an appropriate value during deceleration of an internal combustion engine for an automobile.

Conventionally, a fuel injection device having a configuration as shown in FIG. 1 has been used. In FIG. 1, 2 is a pressure sensor that detects the pressure inside the suction pipe 100 of the internal combustion engine 1, and 3 is a control device, which includes the pressure sensor 2, the ignition device 8,
The amount of fuel required by the internal combustion engine 1 is calculated based on information obtained from an opening sensor 7 that detects the opening of the throttle valve 6, etc., and the solenoid valve 4 is controlled based on the calculation result. In addition, 5 is a fuel supply path, 9
is an air cleaner.

The fuel injection device configured in this way is of the conventional speed and density type, and the amount of fuel supplied to the internal combustion engine 1 is controlled by an electromagnetic injection device driven in synchronization with a rotation signal obtained from the ignition device 8. This can be obtained by adjusting the driving pulse width of the valve 4 according to the output of the pressure sensor 2.

The opening sensor 7 detects the opening in conjunction with the throttle valve 6, and the control device 3 detects the opening speed of the throttle valve 6 to increase the amount of fuel during acceleration.

However, in the conventional system, when the throttle valve 6 closes rapidly as shown in FIG. 3a, the fuel supplied from the solenoid valve 4 to the engine as shown in FIG. b) decreases according to
Since the liquid phase of the fuel adhering to the inner wall of the intake pipe 100 evaporates even after the throttle valve 6 is closed and is inhaled into the engine, the air-fuel ratio (Fig. 3 d) becomes rich transiently, causing a misfire. This had the disadvantage of causing a shock to the vehicle.

This invention was made to eliminate such conventional drawbacks, and includes a bypass valve that bypasses the throttle valve, and when the throttle valve closes at a predetermined speed or higher, the bypass valve is opened for a predetermined time. Moreover, by limiting the amount of fuel supplied to the internal combustion engine to an amount smaller than the amount corresponding to the pressure in the intake pipe at this time, at least corresponding to the closing speed of the throttle valve, the air-fuel ratio can be set to an optimal value. An object of the present invention is to provide a fuel injection device for an internal combustion engine that can be controlled accurately and does not cause misfires.

Hereinafter, an embodiment of the fuel injection device for an internal combustion engine according to the present invention will be described with reference to the configuration diagram shown in FIG. In FIG. 2, parts that are the same as those in FIG. 1 are given the same reference numerals, and their explanation will be omitted, and the parts that are different from those in FIG. 1 will be mainly described. In FIG. 2, the parts indicated by numerals 1 to 9 and 100 are the same as those shown in FIG. 1, and the parts indicated by numeral 10 and after are newly added according to the present invention.

That is, 10 is a bypass valve, 101 and 1
02 is a conduit for bypassing the throttle valve 6, and as shown in FIG. 4a, when the throttle valve 6 opens rapidly, the bypass valve 10 opens for t ₁ hour as shown in FIG. 4c. air is supplied to the engine via the bypass valve 10.

When air is supplied to the intake pipe 100, the pressure inside the intake pipe 100 increases as shown in FIG. 4b, and the control device 3 operates to increase the amount of fuel as shown in FIG. 4d. However, when the throttle valve 6 is closed at a predetermined speed or higher and within a predetermined opening width, the fuel supply amount is reduced to a predetermined value without depending on the output of the pressure sensor 2. Therefore, even if the fuel adhering to the inner wall of the intake pipe 100 evaporates and is taken into the internal combustion engine 1, the air-fuel mixture can be made thinner by the aforementioned bypass air, and the air-fuel ratio will be reduced as shown in FIG. 4e. is maintained at an appropriate value without overloading.

The driving time t ₁ of the bypass valve 10 is determined according to the closing speed of the throttle valve 6 and the variation range, and the amount of fuel supplied by the solenoid valve 4 during this period Q ₁ (Fig. 4 d) is determined by the closing speed of the throttle valve 6. The air-fuel ratio is determined to be optimal according to parameters such as the change width, the passage area of the bypass valve 10, and the like. For example, when the closing speed of the throttle valve 6 is fast and the variation range is large, t ₁ becomes longer and the fuel supply amount increases.
Q ₁ is controlled to be small.

As described above, according to the fuel injection device for an internal combustion engine of the present invention, when the throttle valve is closed at a speed higher than a predetermined speed, the bypass valve is opened for a predetermined time and the amount of fuel supplied to the internal combustion engine is controlled. The configuration is configured to limit the amount to a smaller amount corresponding to at least the closing speed of the throttle valve than the amount corresponding to the pressure in the suction pipe at this time, so even if the throttle valve is rapidly closed, the air-fuel ratio remains at an appropriate value. It exhibits an excellent effect in that it is controlled to prevent misfires.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of a conventional fuel injection device for an internal combustion engine, FIG. 2 is a block diagram showing the configuration of an embodiment of the fuel injection device for an internal combustion engine according to the present invention, and FIGS. d is a diagram for explaining the operation of the fuel injection device for the internal combustion engine shown in FIG. 1, and FIGS. 4a to 4e are diagrams for explaining the operation of the fuel injection device for the internal combustion engine shown in FIG. 2, respectively. This is a diagram. DESCRIPTION OF SYMBOLS 1... Internal combustion engine, 2... Pressure sensor, 3... Control device, 4... Solenoid valve, 5... Fuel supply path, 6...
... Throttle valve, 7... Opening sensor, 8... Ignition device,
9...Air cleaner, 10...Bypass valve, 10
0...Suction pipe, 101,102...Pipe line. In addition,
The same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims] 1. A pressure sensor that detects the suction pressure in the suction pipe of an internal combustion engine, a throttle valve provided in the suction pipe upstream of this pressure sensor, and an opening sensor that works in conjunction with this throttle valve to detect the opening degree of this throttle valve. , a fuel injection means for injecting fuel into the suction pipe, a pipe line provided in the suction pipe for bypassing the throttle valve, a bypass valve for opening and closing the pipe line, and an output of the pressure sensor and the internal combustion engine. The amount of fuel required by the internal combustion engine is calculated based on the information corresponding to the rotation signal and the fuel injection means is controlled, and when the throttle valve is closed at a speed higher than a predetermined speed, the bypass valve is operated for a predetermined period of time. a control device that opens the valve and limits the amount of fuel supplied to the internal combustion engine to an amount that is at least smaller than the amount that corresponds to the pressure in the suction pipe at this time, corresponding to the closing speed of the throttle valve; A fuel injection device for an internal combustion engine.