JPS6027808Y2 - vaporizer - Google Patents

Description

[Detailed description of the invention] This invention relates to a carburetor that returns the fuel in the float chamber to the fuel tank using negative pressure in the manifold when the engine is stopped, and the fuel remaining in the float chamber during long-term engine storage is removed. Its purpose is to prevent problems during engine operation due to oxidation.

If an engine with gasoline remaining in the float chamber of the carburetor is stored for a long period of time, the gasoline will oxidize and turn into gum, which will clog jets and bleed holes, making engine operation, especially starting, difficult.

This invention was developed to eliminate the above-mentioned problem.When stopping the engine, the engine is stopped by closing the fuel cock, and the fuel in the float chamber is drained until the engine has completely stopped. It is designed to extract the.

That is, the fuel in the float chamber is drained and returned to the fuel tank until the engine is completely stopped by a negative pressure operated valve and a negative pressure operated pump in the fuel extraction passage that operate at the same time as the fuel cock is closed. During long-term storage, the inside of the float chamber is kept empty, where there is a risk of fuel oxidation.

Embodiments of the present invention will now be described with reference to the drawings.

The figure is a schematic diagram of the carburetor of the present invention. In the figure, 1 is the engine, 2 is the intake cylinder, 3 is the throttle valve, 4 is the main nozzle that opens into the venturi, 5 is the main jet, 6 is the float chamber, and 7 is the float valve. , 8 is a fuel supply passage, 9 is a fuel tank,
10 is a fuel cock, which is a carburetor with the same function as a conventionally used carburetor.

In the present invention, a negative pressure pump 11 is provided at the bottom of the float chamber 6 of the carburetor to return the fuel in the float chamber 6 to the fuel tank 9, and the suction side of this pump 11 and the bottom of the float chamber 6 A negative pressure operating valve 13 that normally keeps the passage 12 closed is provided in the fuel extraction passage 12 that connects the pump 11 and the valve 13. 16 communicates with the throttle valve downstream of the intake cylinder 2 or the manifold, and this passage 16 is further provided with a cock 17 that is linked to the fuel cock 10 and opens and closes alternately so that it closes when the cock 10 is opened and opens when it is closed. A fuel return passage 18 is provided on the discharge side of the pump 11, and its upper end opens into the tank from the upper part of the fuel tank 9.

The negative pressure operation pump 11 has an operation negative pressure chamber 14 and a pump chamber 1.
The suction check valve 21 and the discharge check valve 22 are connected to a diaphragm 20 which is stretched between the suction check valve 21 and the discharge check valve 22. Further, the negative pressure operated valve 13 is attached at its rear end to a diaphragm 24 so as to open and close the passage 12 by moving the needle valve 23 forward and backward.
2 is kept closed and passage 1 is closed only when negative pressure is applied.
It is configured to open 2.

In the carburetor of the present invention constructed as described above, when the engine is used, when the fuel cock 10 is first opened, the cock 17 interlocked therewith is closed at the same time.

In this case, the negative pressure operated valve 13 is connected to the passage 12 while the engine is stopped.
, the passage 16 remains closed, while the fuel in the tank flows into the float chamber 6 through the float valve 7 to form a constant oil level.

Therefore, in this situation, if the engine is started as in the conventional case, it will start operating.

Next, when the engine is to be stopped, the fuel cock 10 is closed.

When the cock 10 is closed, the inflow of fuel stops, and at the same time the cock 17 is opened, so the manifold negative pressure is reduced to the passage 1.
6 acts on the negative pressure chambers 14 and 15 of the negative pressure operated pump 11 and the negative pressure operated valve 13, and operates the pump 11 at the same time as the needle valve 23 opens. It is returned to the fuel tank 9 through the passage 18.

In this way, the oil level in the float chamber 6 falls, and the main jet 5
When the fuel reaches the end of the engine, the engine runs out of fuel and no longer burns in the cylinder, but the above-mentioned extraction operation continues due to rotation due to inertia, and the remaining fuel is completely extracted until the rotation stops.

When the rotation due to inertia stops, the manifold negative pressure disappears, so the operation of the negative pressure pump 11 stops, and the negative pressure valve 13 also closes the passage 12 by the needle valve 23 that advances due to the tension of the spring 25. .

Therefore, if the engine is stored in this state for a long period of time, there will be no fear of fuel oxidation in the float chamber as described above.

The above is a stop operation when storing the engine for a long period of time. However, if the engine is in the middle of use and there is no need to drain the fuel from the float chamber, do not close the fuel cock 10 when stopping the engine and press the stop button (not shown in the figure). If the button is pressed, the engine will stop by cutting off the current to the ignition system, regardless of the fuel in the float chamber.

As mentioned above, in the present invention, when the engine is stopped, the fuel in the float chamber is used until the engine is completely stopped by using the negative pressure operated valve and the negative pressure operated pump in the fuel extraction passage, which operate at the same time as the fuel cock is closed. Since the structure is such that the fuel is removed and the fuel tank is returned, it is possible to leave the float chamber completely empty of fuel after the engine is stopped, and there is no need to worry about fuel oxidation in the float chamber even if the engine is stored for a long time. This has the effect of completely eliminating the above-mentioned obstacles that make starting and driving difficult.

[Brief explanation of the drawing]

The drawing is a schematic diagram showing an embodiment of the vaporizer of the present invention. 1...Engine, 2...Intake cylinder, 4.
... Main nozzle, 5 ... Main jet, 6 ... Float chamber, tail ... Fuel supply passage, 9 ... Fuel tank, 10 ... ...Fuel cock, 11...Negative pressure operation valve 12...
Fuel extraction passage, 13... Negative pressure operation valve, 14, 1
5...Negative pressure chamber, 16...Negative pressure outlet passage, 17...Cock.

Claims (1)

[Scope of utility model registration request] a negative pressure operated pump that returns fuel in the float chamber to the fuel tank; a negative pressure operated valve that is provided in a fuel extraction passage connecting the pump and the bottom of the float chamber and that normally keeps the passage closed; A negative pressure operated valve and a cock provided in a manifold negative pressure outlet passage communicating with each negative pressure chamber of the negative pressure operated pump, which operates in conjunction with a fuel cock, closes when the cock is opened, and opens when the cock is closed. vaporizer.