JPS6021484Y2 - Fuel oil level control device in carburetor - Google Patents

Description

[Detailed description of the invention] The present invention relates to a fuel oil level control device that always maintains the fuel oil level of float g in a carburetor at a constant level despite an excessive increase in fuel supply pressure from a fuel tank. .

In automobiles, it is common practice to configure the fuel tank in a sealed type to prevent the evaporated fuel generated inside the tank from being released into the atmosphere.
When the internal pressure of the fuel tank increases due to heat absorption, etc., this causes an increase in the fuel supply pressure.For this reason, in conventional carburetors, the fuel oil level in the float chamber rises, which upsets the air-fuel ratio of the mixture supplied to the engine. This has the disadvantage of increasing harmful components in exhaust gas.

Therefore, in order to eliminate such adverse effects, for example,
As shown in Publication No. 3-16343, a piston-shaped valve seat member having a valve seat that engages with a float valve is slidably fitted into the upper part of the float chamber, and a stopper fixed to the earthen wall is fitted. When the internal pressure of the fuel tank acting on the valve seat member increases above a certain value, the valve seat member is biased by the spring so as to maintain engagement between the valve seat and the float valve. Conventionally, by displacing the float valve toward the float valve side against the pressure, the float valve remains closed even when the internal pressure of the fuel tank increases, and the fuel oil level in the float chamber can always be maintained at a constant level. Although it has been proposed,
With conventional systems, in order to adjust the oil level in the float chamber, which should be controlled at a constant level by the float valve, it is necessary to replace the float valve and the float itself, which is troublesome and increases costs. be.

The purpose of the present invention is to provide a device that can eliminate the above-mentioned problems and has high working accuracy and excellent durability.The feature of the present invention is to provide a valve seat in the form of a valve seat at the outlet of the fuel inflow path of the float chamber. and a float floating on the fuel oil level in the float chamber is linked to a float valve that engages with the valve seat, and when the float falls below a certain level, the float valve is opened. a valve seat member having the valve seat and slidingly movable up and down on the earthen wall of the float chamber; a movable stopper that restricts the upper limit of the valve seat member; a spring that urges the valve seat member in the direction of engagement with the movable stopper; and a spring that is stretched between the valve seat member and the earthen wall of the float chamber. and a diaphragm defining a pressure receiving chamber communicating with the fuel inflow path between the earth wall and the fuel inflow path.

Hereinafter, embodiments of the present invention will be explained with reference to the drawings.
Inside the float chamber 1 of the carburetor, there is a fuel inlet passage 2 that connects to a closed fuel tank (not shown) above the fuel oil level F stored therein, and a fuel inlet passage 2 that connects to a closed fuel tank (not shown) above the fuel oil level F stored therein, and a fuel inlet passage 2 that connects to a closed fuel tank (not shown) below the oil level F. A fuel outflow path (not shown) connected to the fuel nozzle opens.

A valve seat 3 is installed at the outlet of the fuel inflow path 2, and a float valve 4 is engaged with the valve seat 3.

A swinging arm 7 is supported on a pivot shaft 5 horizontally suspended in the float chamber 1, and a float 6 that floats on the oil surface F is connected to the tip of the swinging arm 7. An operating piece 8 supporting the lower end of the float valve 4 is fixedly provided.

Therefore, when the fuel in the float chamber 1 is consumed due to engine operation and the oil level F decreases, the float 6 follows this and descends, swinging the swinging arm 7 and the actuating piece 8 downward. Along with this, the float valve 4 also descends, so the float valve 4 separates from the valve seat 3 and opens the fuel inlet passage 2, and the fuel in the fuel tank (not shown) is replenished into the float chamber 1 from the fuel inlet passage 2, and the oil level is lowered. F increases.

Then, the float 6 also begins to rise, and when the oil level F reaches a specified level, the float valve 4 is seated on the valve seat 3 by the buoyancy of the float 6, and the fuel inflow path 2 is closed.

Up until now, the configuration has been conventional, and when the float valve 4 is closed, the upward rotational moment of the swinging arm 7 due to the buoyancy of the float 6 acts on the upper end surface of the float valve 4. This is equal to, but greater than, the downward rotational moment of the swinging arm 7 due to the pressure, that is, the fuel supply pressure. Therefore, if the fuel supply pressure increases, the buoyancy of the float 6 necessary to close the float valve 4 In other words, the level of the oil surface F naturally rises.

The present invention is designed to prevent the float valve 4 from opening even if the fuel supply pressure increases, and further has the following configuration.

That is, a diaphragm 1 defining a pressure receiving chamber 110 that communicates with the fuel inflow path 2 is disposed on the earthen wall of the float chamber 1.
The outer periphery of the diaphragm 11 is sandwiched, and a valve seat member "7" having the valve seat 3 and slidably inserted into the earthen wall of the float chamber 1 is connected to the center of the diaphragm 111.

The valve seat member 17 is provided with a valve hole 17A that communicates the valve seat 3 with the pressure receiving chamber 110.

The valve seat member 17 is pressed upward by a spring 11 and is normally moved by a movable stopper 19 provided on the upper wall of the pressure receiving chamber 110.
is held at the upper limit position.

The movable stopper 19 is in contact with an adjustment screw 20 screwed into the upper wall of the pressure receiving chamber 110, so by appropriately rotating the screw 20, the position of the stopper 19 relative to the upper wall of the pressure receiving chamber 110 can be adjusted. Therefore, the initial position of the valve seat member 17 can be adjusted, and thereby the oil level in the float chamber 1, which should be controlled at a constant level by the float valve 4, can be adjusted as desired.

Therefore, when the oil level F is at a specified level and the float valve 4 is closed, if the pressure in the fuel inlet passage 2 rises excessively, the pressure acts on the upper end surface of the float valve 4 and the float valve 4 is closed. The valve 4 is pressed downward, and at the same time, the above pressure presses the valve seat member 17 downward against the spring 18 through the diaphragm 111, so that the float valve 4 is eventually displaced downward together with the valve seat member 17. The closed state can still be maintained by simply doing this, and the oil level F does not rise due to the inflow of fuel, and is maintained within the permissible level range.

As described above, according to the present invention, the valve seat 3 is formed at the outlet of the fuel inflow path 2 of the float chamber 1, and the float valve 4 that engages with the valve seat 3 is connected to the fuel oil level in the float chamber 1. In a vaporizer in which a float 6 floating above F is interlocked and the float valve 4 is opened when the float 6 falls below a certain level, the valve seat 3 is provided to prevent soil in the float chamber 1. A valve seat member 17 that slides up and down on the wall; is supported on the earthen wall of the float chamber 1 so that its position can be adjusted, and engages with the valve seat member 17 to restrict the upper limit of the valve seat member 17. a movable stopper 19; a spring 18 that urges the valve seat member 17 in the direction of engagement with the movable stopper 19; a spring 18 that is stretched between the valve seat member 17 and the soil wall of the float chamber 1 and A pressure receiving chamber 11 communicating with the fuel inflow path 2 between the wall and the wall.
0, the diaphragm 111 and; Therefore, the valve seat member 17 can be displaced toward the float valve 4 side, and the engagement between the valve seat 3 and the float valve 4 can be maintained. By maintaining the closed state, the fuel oil level F in the float chamber 1 can be always maintained at a constant level, and the concentration of the generated air-fuel mixture is stabilized.

Moreover, since the initial position of the valve seat member 17 can be arbitrarily adjusted by adjusting the movable stopper 19, the float valve 4
The oil level in the float chamber 1, which should be controlled at a constant level, can be adjusted quickly and easily, and there is no need to replace the float valve or the float 6 itself when adjusting the level, improving work efficiency and reducing costs. can contribute.

Moreover, even if the abutting position between the stopper 19 and the valve seat member 17 deviates due to the adjustment operation of the movable stopper 19, the valve seat member 17, which is slidably guided by the earthen wall of the float chamber 1, is Since the diaphragm 111 does not fall down, it is always properly connected to the diaphragm 111, and the diaphragm 111 is not forcibly twisted, thus increasing the working precision of the diaphragm 111 and improving its durability. can be done.

[Brief explanation of the drawing]

The drawing is a longitudinal sectional side view of an embodiment of the device of the present invention. F... Oil level, 1... Float chamber, 2.
...Fuel inflow path, 3...Valve seat, 4...
...Float valve, 6...Float, 17...
...Valve seat member, 19...Movable stopper, 1
10... Pressure receiving chamber, 111... Diaphragm.

Claims (1)

[Scope of utility model registration request] A valve seat 3 is formed at the outlet of the fuel inlet passage 2 of the float chamber 1, and the float valve 4 that engages with the valve seat 3 is connected to the float chamber 1.
The float 6 floating on the fuel oil level F inside is interlocked,
When the float 6 falls below a certain level, the float 7
In the carburetor, the valve seat member 17 has the valve seat 3 and is slidable up and down on the earthen wall of the float chamber 1; a movable stopper 19 that is supported in a position-adjustable manner and that engages with the valve seat member 17 to restrict the upper limit of the valve seat member 17;
the valve seat member 17 in the direction of engagement with the movable stopper 19;
a diaphragm that is stretched between the valve seat member 17 and the earthen wall of the float chamber 1 to prevent the pressure receiving chamber 110 communicating with the fuel inlet passage 2 between the earthen wall and the earthen wall; A fuel oil level control device in a carburetor, characterized by comprising: 111;