JPH0681932B2 - Engine fuel supply - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel supply device for an engine, and in particular, it aims to improve the startability of an internal combustion engine and simplifies the configuration to reduce the cost and make it easy to put into practical use. The present invention also relates to a fuel supply device for an engine, which can easily control fuel supply.

[Conventional technology]

An internal combustion engine produces an air-fuel mixture by a carburetor and burns the air-fuel mixture in a combustion chamber to obtain heat energy. Therefore, there is a fuel supply device for supplying necessary fuel to an internal combustion engine, mixing it with air at an appropriate ratio, and further appropriately atomizing and vaporizing the fuel and guiding it to the combustion chamber. The fuel supply system is generally
It consists of a fuel tank, a fuel filter, a fuel pump, and a carburetor. The fuel pump includes a mechanical fuel pump and an electromagnetic fuel pump. The electromagnetic fuel pump is
It is electrically operated and highly reliable, and it does not need to be directly attached to the internal combustion engine, so that it has a high degree of design freedom.
However, the electromagnetic fuel pump is a system that is driven at the same time when the internal combustion engine is started. Therefore, when the internal combustion engine is restarted at high temperature after heavy load operation, the fuel is excessively supplied to the carburetor by the electromagnetic fuel pump, resulting in excess fuel and the air-fuel ratio being excessively rich, resulting in startability. There was an inconvenience that it was damaged. In order to solve this inconvenience, as a fuel supply device, for example, Japanese Patent Publication No. 59-20869 and Japanese Utility Model Publication No. 59-1.
There are those disclosed in Japanese Patent No. 6529 and Japanese Utility Model Laid-Open No. 50-76220.

[Problems to be solved by the invention]

However, since the conventional fuel supply device requires a device such as a timer device that operates in a predetermined time in conjunction with a start operation during starting of the internal combustion engine and a temperature sensitive control device that detects the temperature state of the internal combustion engine. However, the number of parts increases, the structure becomes complicated, the cost becomes high, and it is difficult to put it into practical use.

[Object of the Invention]

Therefore, an object of the present invention is to eliminate the above-mentioned inconvenience, prevent excessive fuel and vaporized fuel from being fed at the time of starting the internal combustion engine, and improve startability, while simplifying the configuration and reducing the cost. It is to realize a fuel supply device for an engine that can be easily put into practical use and can easily control fuel supply.

[Means for solving problems]

To achieve this object, the present invention provides an electromagnetic fuel that suspends fuel supply when the starter switch of an internal combustion engine is in the on state and the throttle switch detects a carburetor throttle valve opening state in which the opening is greater than or equal to a predetermined opening. It is characterized by having a pump.

[Action]

According to the configuration of the present invention, when the starter switch is in the ON state and the throttle switch detects the carburetor throttle valve opening state in which the opening degree is equal to or larger than the predetermined opening degree, the driving of the electromagnetic fuel pump is stopped and the fuel is fed. Pause. Thus, at the time of starting the internal combustion engine, it is possible to prevent excessive fuel and vaporized fuel from being fed to improve startability, and it is not necessary to separately provide a device such as a conventional timer device. The number of points can be reduced, the structure can be simplified, the cost can be reduced, and the practical application can be facilitated, and the fuel supply control can be easily achieved.

Example of Invention

Embodiments of the present invention will be described in detail and specifically below with reference to the drawings.

The figure shows an embodiment of the present invention. In the figure,
2 is a fuel tank and 4 is a vaporizer. The fuel in the fuel tank 2 is sent to the carburetor 4 by an electromagnetic fuel pump 6. The fuel pump 6 communicates with an ignition switch 14 via a relay circuit 12 provided with a contact 8 and a coil 10. This ignition switch 14 is a battery
I have contacted 16. The contact 8 of the relay circuit 12 is normally closed. The coil 10 is connected to a throttle switch 18 which detects the opening state of a carburetor throttle valve (not shown). The throttle switch 18 communicates with a starter switch 20 which is turned on when the internal combustion engine is started. In the relay circuit 12, when the starter switch 20 is in the ON state and the throttle switch 18 detects the carburetor throttle valve opening state in which the opening is equal to or more than a predetermined opening, the contact 8 is opened by the electric current flowing through the coil 10, and the ignition switch is opened.
The configuration is such that the communication between 14 and the fuel pump 6 is cut off. The predetermined opening degree of the carburetor throttle valve detected by the throttle switch 18 is the throttle valve opening degree that is larger than the throttle valve opening degree and the throttle positioner opening degree at low temperature, and the opening degree that does not burden the driver. It is degree. Therefore, when the engine is operating at low temperature and the throttle positioner is operating during deceleration, the drive of the fuel pump 6 is not stopped and the proper air-fuel ratio is ensured.

The operation of the embodiment of the present invention will be described below.

When the internal combustion engine is started, particularly when the engine is restarted at high temperature, the ignition switch 14 and the starter switch 20 are turned on. Also, at this time, the driver empirically depresses the accelerator pedal slightly. This is to prevent the air-fuel ratio from becoming rich due to excess fuel at the time of restart when the engine is at a high temperature, thus deteriorating the startability. The amount of depression of the accelerator pedal by the driver is a state in which the throttle valve is larger than the opening when the engine is operating at low temperature and the throttle positioner opening, and is the amount of depression that does not burden the driver. The depression of the accelerator pedal turns on the throttle switch 18. Therefore, the contacts of the starter switch 20 and the throttle switch 18 are closed, and the current flows through the coil 10 of the relay circuit 12. As a result, the contact 8 of the relay circuit 12 is opened, and the communication between the ignition switch 14 and the fuel pump 6 is cut off. Therefore, the fuel pump 6 is not driven, and the carburetor 4 is
To stop fuel delivery to. When the starting operation is completed and the starter switch 20 is turned off, the coil 10
Since no current flows through the contact 8, the contact 8 is restored and closed, and the relay circuit 12 reconnects the ignition switch 14 and the fuel pump 6. Then, the fuel pump 6 is driven normally.

As a result, when restarting at high engine temperature, excessive fuel and evaporated fuel are not sent to the carburetor 4,
The startability can be improved. Moreover, since it is not necessary to separately provide a device such as a timer device or a temperature-sensitive control device as in the conventional case, the number of parts can be reduced, the configuration can be simplified, the cost can be reduced, and the practical application can be facilitated. Further, by controlling the drive of the fuel pump 6 using the throttle switch 18, a conventional switch mechanism can be used, which can be inexpensive.
Further, at the time of starting the internal combustion engine, the driver can stop the driving of the fuel pump 6 by merely depressing the accelerator pedal and operating the starter switch 20 as in the conventional case, so that the driver is not burdened. The fuel supply control can be easily achieved. Further, the configuration of this embodiment facilitates maintenance and inspection, which is practically advantageous.

〔The invention's effect〕

As is apparent from the above detailed description, according to the present invention,
When the starter switch is in the on state and the throttle switch detects the carburetor throttle valve opening state in which the opening degree is equal to or larger than the predetermined opening degree, the electromagnetic fuel pump suspends the fuel supply. With this, at the time of starting the internal combustion engine, it is possible to improve the startability by preventing the supply of excessive fuel and evaporated fuel, and it is not necessary to separately provide a device such as a conventional timer device. Can be reduced, the configuration can be simplified, the cost can be reduced, and the practical application can be facilitated.

Also, by controlling the drive of the electromagnetic fuel pump using the throttle switch, the conventional starting operation can be performed at the time of starting, so that the fuel supply control is easy without burdening the driver. Can be achieved.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention and is a schematic explanatory view of a fuel supply device. In the figure, 2 is a fuel tank, 4 is a carburetor, 6 is an electromagnetic fuel pump, 12 is a relay circuit, 18 is a throttle switch, and 20 is a starter switch.

Claims (1)

[Claims] 1. An electromagnetic fuel pump is provided which suspends fuel supply when a starter switch of an internal combustion engine is turned on and a throttle switch detects a carburetor throttle valve opening state of a predetermined opening or more. Characteristic engine fuel supply device.