JPS6127572B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for preventing starting failure caused by residual fuel in a float chamber in a carburetor of an internal combustion engine.

For example, engines used in emergency generators, snow blowers, harvesters, etc. are not used throughout the year and are often stopped and stored for several months. In this case, most of the gasoline in the float chamber of the carburetor will evaporate during that time, leaving only the less volatile portion of the gasoline-powered engine, which may cause starting problems when used later, or in some cases. There was a problem that solid components adhered to the vicinity of the nozzle in the carburetor and the engine could not be started unless it was removed.

The purpose of the present invention is to solve the above-mentioned problems.The present invention is directed to arranging a sealed chamber 2 below the float chamber 1 of a carburetor at a position that receives heat from the engine. A communication pipe 3 is connected to the bottom of the float chamber, and the residual fuel in the float chamber is lowered into the closed chamber 2 by the contraction of the residual air in the closed chamber 2 as the ambient temperature of the closed chamber 2 decreases when the engine is stopped. The oil level in the float chamber 1 is positioned below the nozzle position to prevent starting failure due to residual fuel in the float chamber of the carburetor.

In Fig. 1, the upper part of the bottomed surface is constricted to form a sealed chamber 2, the lower part of a tube 3b attached by welding or the like to the constricted part is opened slightly above the bottom of the sealed chamber 2, and the rubber tube 3a is attached to the upper part. An example in which one end of the float chamber 1 is fitted, and the other end is fitted into a cylindrical portion 1a formed at the lower part of the float chamber 1, thereby making both chambers 1 and 2 communicate with each other.

In FIG. 2, the sealed chamber 2 is formed in a Kunku-shape, and a cylindrical opening 2a is formed on the side surface near the bottom. One end of a rubber tube 3a is fitted into this opening 2a, and the other end is closed in the same manner as in FIG. 1. 2 shows an example in which it is fitted into the cylindrical portion 1a of the float chamber 1 to connect both chambers 1 and 2.

In the figure, 4 is a float, 5 is a needle valve, 6 is a nozzle, 7 is an intake passage, and 8 is a choke valve.

In the present invention, with the above-described configuration, during engine operation, fuel is sent from the tank T to the float chamber 1 via the cock C and the needle valve 5, and the oil level is maintained at, for example, L1, so that the engine can be operated in exactly the same manner as in the past. will be done. In this case, the sealed chamber 2 is affected by the surrounding heat of the engine, etc., and due to the expansion of the air remaining in the chamber 2 and the vapor pressure of the fuel, the oil level of the fuel in the chamber 2 is, for example, at a position L2.

When the engine is stopped and the tank C is closed, the temperature around the sealed chamber 2 gradually decreases, the air and fuel vapor in the chamber 2 contract, and the oil level rises to, for example, the position L3. The oil level inside decreases and descends to approximately L4 position.

If this is left for a long period of time, part of the fuel will evaporate and the oil level will further drop from the position L4 to a position considerably lower than the suction port 6a of the nozzle 6, for example at L5. Therefore, in the past, solid components with low volatility adhered to the vicinity of the nozzle during the descent from L1 to L5', but this does not occur in the present invention.

Furthermore, when starting the engine, when the tank C is opened, new fuel is supplied from the tank into the float chamber 1, but at this time, the oil level in the sealed chamber 2 is still at the L3 position, and the volatile Most of the components with low fuel content remain in the closed chamber 2, and new fuel is drawn into the engine through the nozzle 6, making it easy to start the engine.

Note that after the engine starts, the temperature around the sealed chamber 2 gradually rises, and as the air in the sealed chamber 2 expands and the vapor pressure of the fuel increases, the oil level drops from L3 to L2 and the volatility in the chamber 2 increases. The lower part of the fuel flows out into the communication pipe 3, but the outflow is gradual and is gradually mixed with new fuel in the float chamber 1 and consumed, so there is no problem with engine operation.

As described above, the present invention can prevent starting failures in the conventional engine by simply adding a simple device to the conventional carburetor, and since the device does not require precision machining, it can be easily and easily installed.
Can be manufactured cheaply.

In addition, if a flexible tube such as rubber is used as the communication tube 3 as in the embodiment, the sealed chamber 2 can be placed at an arbitrary position. In this case, it is best to consider the ambient temperature of the closed chamber during engine operation when arranging it, and as a result of experiments, it has been found that the appropriate temperature is 50 to 60°C.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing an example of the apparatus of the present invention, and FIG. 2 is a longitudinal sectional view of a part of a modified example. 1 is a float chamber, 2 is a sealed chamber, 3 is a communication pipe, 4
is a float, 5 is a needle valve, and 6 is a nozzle.

Claims (1)

[Claims] 1. A sealed chamber is placed below the float chamber of the carburetor in a position that receives the heat of the engine, and the vicinity of the bottom of the sealed chamber is connected to the bottom of the float chamber through a communication pipe to determine the ambient temperature of the sealed chamber when the engine is stopped. The residual fuel in the float chamber of a carburetor is configured so that the residual fuel in the float chamber is lowered into the closed chamber by the contraction of the residual air in the closed chamber due to a decrease in the temperature, and the oil level in the float chamber is positioned below the nozzle position. A device to prevent poor starting.