JPH0234460Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a carburetor float chamber fuel extraction device.

Conventional technology In conventional general-purpose small gasoline engines equipped with a so-called float type carburetor, if the engine is electrically stopped using the stop button and then left for a long time, the gasoline accumulated in the float chamber of the carburetor will vaporize. As the container undergoes corrosion, the gasoline deteriorates and the foreign substances generated at this time cause the carburetor to malfunction, resulting in failure to start the next time it is used. In addition, in engines equipped with a fuel tank on the upper part of the engine body, the air vent of the fuel tank is generally provided with an air vent hole communicating with the atmosphere in the fuel tank cap. With this structure, when the fuel tank is full of gasoline or there is a lot of gasoline, engine vibration, tilting operation, or temperature rise during operation causes gasoline or gasoline vapor in the tank to leak or spout out from the air breather. There was a risk of a fire starting if the heated parts of the muffler were touched, and the tank and engine body were contaminated with spilled gasoline.

Purpose The purpose of the present invention is to eliminate the above-mentioned drawbacks, improve safety and prevent contamination, or to automatically drain the fuel in the float chamber to the fuel tank when the engine is stopped so that the engine can be left unused for a long time. Another object of the present invention is to provide a fuel extraction device for a carburetor that does not cause corrosion of the carburetor or deterioration of the gasoline in the float chamber, thereby preventing starting failure due to fuel clogging during the next use.

Embodiment An embodiment of a fuel extraction device for a carburetor according to the present invention will be described below with reference to FIGS. 1 to 3.

In Fig. 1, 1 is a fuel tank, 2 is a sealed fuel tank cap, 3 is a carburetor, and 4 is a fuel tank and three-way vent pipe tank. 5 and 6 are fuel pipes, 7 is a drain pipe, 8 is a ventilation pipe, 9 is an air vent pipe, 10 is a carburetor float chamber, and 11 is a carburetor air vent.

In Figure 2, 4 is the fuel tank and three-way ventilation pipe.
FIG. 3 is an explanatory diagram showing the same switch when it is turned on and when it is turned off. 4 is the main body of the fuel tank and three-way ventilation pipe, 7a is the connection part of the drain pipe 7 from the bottom of the float chamber 10 of the carburetor 3, 8a is the connection part of the ventilation pipe 8 from the fuel tank 1, and 9a is the air vent pipe 9 The connection part 12 is the valve of the fuel tank/three-way ventilation pipe tank 4. Note that the operation of the fuel tank and three-way vent pipe 4 may be structured in conjunction with an electric engine stop device.

Next, the operation of the above embodiment will be explained.

This idea utilizes the negative pressure inside the fuel tank that occurs when the gasoline temperature inside the fuel tank 1 drops.
The gasoline accumulated in the carburetor float chamber 10 is drained into the fuel tank 1. That is, when the engine switch is turned off, the engine is stopped, and the fuel outlet/three-way ventilation outlet 4 is set to the OFF position as shown in FIG. The connection between the vent pipe connecting portion 8a and the air vent pipe connecting portion 9a of the vent pipe 8 of the fuel tank 1 is also cut off, and at the same time, the connection between the vent pipe connecting portion 8a and the drain pipe connecting portion 7a is also cut off.
can be understood. Fuel tank 1 is now sealed, but
When the temperature of the fuel tank 1 and gasoline rises and the pressure inside the fuel tank 1 rises, this pressure passes through the vent pipe 8 and flows back through the drain pipe 7, displacing the gasoline accumulated in the float chamber 10 of the vaporizer 3 and vaporizing it. This prevents the pressure inside the fuel tank 1 from becoming abnormally high due to the air being released from the fuel tank air vent. On the other hand, if the temperature decreases, the pressure inside the fuel tank 1 decreases and negative pressure is generated, so that the gasoline remaining in the float chamber 10 flows into the fuel tank via the drain pipe 7 and vent pipe 8 connected to the bottom. It is sucked up within 1.

When the engine is running, the fuel tank and three-way vent pipe 4 is set to the ON position, and the fuel pipes 5 and 6 are connected as shown in Fig. 2, and the fuel is guided from the fuel tank 1 to the carburetor 3. The air vent of the fuel tank 1 is opened to the atmosphere through a vent pipe 8 and an air vent pipe 9. At this time, the drain pipe connection part 7
a is closed. When the fuel tank 1 is filled with gasoline or there is a lot of gasoline, the gasoline or gasoline vapor in the fuel tank 1 may leak or spout due to vibrations, tilted operation, or temperature rise during operation, but the air vent pipe 9 guides it to a safe location. I'm scared.

Effects of the invention As mentioned above, the fuel extraction device for a carburetor according to the invention seals the fuel tank with the fuel tank and three-way vent pipe at the same time as the engine stops or after the engine stops, and reduces the temperature of the gasoline in the fuel tank. Using the negative pressure generated by the system, the gasoline accumulated in the float chamber is automatically extracted through the drain pipe and vent pipe and returned to the fuel tank. In addition, during operation, the air vent pipe is used to guide the gasoline and gasoline vapor that escape and spout to a safe place, so even if the engine is left unused for a long time, the carburetor will not corrode or the gasoline will change and deteriorate. This improves safety by preventing troubles such as engine starting problems and dangers such as fires caused by spilled gasoline.

[Brief explanation of the drawing]

Figures 1 to 3 are examples of the present invention, Figure 1 is an explanatory diagram of the configuration of the fuel extraction device, Figures 2 and 3 are the ON of the fuel tank and three-way vent pipe tank 4, respectively.
FIG. 1... Fuel tank, 2... Fuel tank cap, 3... (float type) carburetor, 4... Fuel pot and three-way ventilation pot, 7... Drain pipe,
8...Vent pipe, 9...Air vent pipe, 10
...Float room.

Claims (1)

[Scope of utility model registration request] In a general-purpose engine equipped with a float type carburetor that automatically drops fuel, a fuel tank equipped with a three-way valve is provided in the fuel pipe connecting the bottom of the sealed fuel tank chamber and the carburetor, and the fuel tank is equipped with a three-way valve. The fuel tank and the bottom of the float chamber of the carburetor are each connected by a drain pipe through a vent pipe, and the fuel tank and the three-way tank are further connected to an air vent pipe. The fuel tank connects the vent pipe and the air vent pipe connection part when the fuel pipe entrance and exit are communicated with each other during engine operation, and closes the drain pipe connection part, and when the engine is stopped, the fuel pipe entrance and exit are blocked. At this time, the vent pipe and the drain pipe are communicated with each other, and the air vent pipe connection portion is closed to form a sealed passage between the upper space in the fuel tank and the float chamber to eliminate the negative pressure generated due to the temperature drop in the fuel tank. A fuel extraction device for a carburetor, wherein the fuel tank is configured to return gasoline accumulated in the float chamber to the fuel tank via the fuel tank.