JPS6027809Y2 - vaporizer - Google Patents

Description

[Detailed description of the invention] This invention relates to a carburetor that extracts fuel from the float chamber into a fuel reservoir using negative pressure in the manifold when the engine is stopped, and then allows this fuel to be drawn into the engine only during high-load operation. The main purpose is to prevent problems during engine operation due to oxidation of fuel remaining in the float chamber during long-term storage of the engine.

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 gas, which will clog jets and bleed holes, making engine operation, especially starting, difficult.

In view of the above points, the present invention is designed to draw the fuel in the float chamber into the fuel reservoir using the manifold negative pressure when the engine is stopped, and to inhale this fuel into the engine only during the next high load operation. The engine can be stored for a long time in a fuel chamber, which not only avoids problems caused by oxidation of the fuel in the float chamber, but also allows the removed fuel to be used under high loads.

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 venturi, 4 is the slot valve, 5 is the main nozzle that opens into the venturi 3, 6 is the main fuel jet, and 7 is the float. A chamber, 8 is a float valve, 9 is a fuel supply passage, 10 is a fuel tank, and 11 is a fuel cock.The above is a conventional carburetor.

The present invention provides a fuel reservoir 12 at the lower part of the float chamber 7 of the carburetor as described above, and a fuel extraction passage 13 that connects the fuel reservoir 12 and the bottom of the float chamber 7, with the passage 13 kept closed at all times. A negative pressure operating valve 14 is provided, and a manifold negative pressure outlet passage 16 communicating with the negative pressure chamber 15 of the valve 14 is provided with a cock that is linked to the fuel cock 11, closes when the fuel cock 11 is opened, and opens when the fuel cock 11 is closed. 17, a negative pressure return delay valve 18 is provided between the cock 17 and the negative pressure chamber 15, and a fuel suction passage 20 opens to the fuel reservoir 12 through a jet 19 to the venturi portion 3 of the intake cylinder 2. It has been established.

The fuel reservoir 12 is filled with a fuel-containing material 21 such as polyurethane sponge or steel wool, and the suction port of the fuel suction passage 20 is exposed therein.

In this way, even if the fuel is oxidized, only the upper surface of the impregnated material 21 is exposed to air, and since the impregnated material 21 also performs a filtering action, it is possible to prevent the oxidized fuel from being sucked out.

Further, the negative pressure operated valve 14 has a diaphragm 23 at its rear end so that the passage 13 is opened and closed by the forward and backward movement of the needle valve 22.
A spring 2 is attached to the spring 2 and compressed within the negative pressure chamber 15
4, the passage 13 is normally kept closed, and the passage 13 is opened only when negative pressure is applied, and the negative pressure return delay valve 18 is configured, for example, as shown in the figure.
It has a structure in which a small-diameter through hole 25 and a check valve 26 are provided in parallel in the passage 16. When a manifold negative pressure acts on the passage 16, the check valve 26 immediately opens and removes the negative pressure. However, when the manifold negative pressure disappears, the check valve 26 does not open and the negative pressure in the negative pressure chamber 15 is reduced through the small diameter through hole 25.
The return of the negative pressure is delayed, and the needle valve 22 also closes with a delay of that amount of time.

In the carburetor of the present invention configured as described above, when the fuel cock 11 of the engine is opened, the cock 17 that operates in conjunction with the fuel cock 11 is opened.
close at the same time.

In this case, since the negative pressure operating valve 14 is in the same state as when the engine is stopped, the passage 16 is closed while the fuel in the tank flows into the float chamber 7 through the float valve 8.
Form a constant oil level.

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

Next, engine stoppage will be explained when the engine will be stored for a long period of time.

In this case, when the engine is stopped, the fuel cock 11 is first closed, and then an engine stop button (not shown in the figure) is pressed.

).

When the fuel cock 11 is closed, the fuel flowing into the float chamber 7 is cut off, and at the same time the cock 17 is opened, so the negative pressure operating valve 14 is opened by the manifold negative pressure, and the fuel in the float chamber 7 flows into the fuel reservoir 12. It is extracted.

On the other hand, the engine 1 stops when it finishes rotating due to inertia, and at the same time the manifold negative pressure disappears, but the negative pressure operating valve 14 is activated by the negative pressure in the negative pressure chamber 15 due to the action of the negative pressure return delay valve 18 as described above. Since its extinction is delayed, the float chamber 7 closes after the fuel in the float chamber 7 is completely removed by that amount of time.

Therefore, if the engine is stored in this state, fuel oxidation in the float chamber as described above can be avoided, and the extracted fuel can be stored by capping the air hole 27 of the fuel reservoir 12 as shown by the chain line in the figure. This fuel is sucked out through the jet 19 by the venturi negative pressure when the throttle is fully opened and the engine rotates at high speeds when the engine is restarted, and is supplied to the engine as additional fuel during high loads.

The above is a stop operation when the engine is stored for a long time, but if the engine is in use and there is no need to drain the fuel from the float chamber because the stop time is short, etc., do not close the fuel cock 11 when the engine is stopped. When the engine stop button is operated, the engine stops by cutting off the current to the ignition system, regardless of the fuel in the float chamber.

As described above, the present invention includes a cock that opens and closes the manifold negative pressure outlet passage in conjunction with the fuel cock, a negative pressure operated valve that opens and closes the float chamber fuel extraction passage when the engine is stopped, and the negative pressure operated valve. A negative pressure return delay valve that controls opening and closing operations;
By closing the fuel cock when the engine is stopped, the fuel in the float chamber is drained into the fuel reservoir.
Moreover, since this fuel is supplied to the engine only during the next high load operation, the float chamber can be emptied after the engine is stopped, and therefore, even if the engine is stored for a long time, fuel oxidation in the float chamber can be prevented. This not only prevents problems caused by this, but also allows the extracted fuel to be used during the next high-load operation, which has the effect of improving high-load performance.

[Brief explanation of drawings]

The drawing is a schematic diagram showing an embodiment of the vaporizer of the present invention. 1...Engine, 2...Intake cylinder, 3.
...Venturi 4...Slot valve, 5...Main nozzle, 6...Main fuel jet, 7...Float chamber, 9...・・・
・Fuel supply passage, 11... Fuel cock,
12...Fuel reservoir, 13...Fuel extraction passage, 14...Negative pressure operating valve, 15...
Negative pressure chamber, 16... Manifold negative pressure outlet passage,
17...Cook, 1.....Negative pressure return delay valve 19...Jet, 20...Fuel suction passage.

Claims (1)

[Scope of utility model registration request] A fuel reservoir is provided at the bottom of the float chamber, and a negative pressure operated valve is provided in the fuel extraction passage connecting this fuel reservoir and the bottom of the float chamber, and the negative pressure operated valve is provided to keep the passage closed at all times. A manifold negative pressure takeout passage communicating with the manifold has a cock that works with the fuel cock, closes when the fuel cock is opened, and opens when the fuel cock is closed.
and a negative pressure return delay valve is provided between the conch and the negative pressure chamber, and a fuel suction passage is provided in the fuel reservoir that opens through a jet in a part of the venturi of the intake cylinder. vessel.