JPH0356696Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to an improvement in a check valve assembly installed in a vent pipe that connects an automobile gasoline tank above the liquid level and a charcoal canister.

As shown in Fig. 1, gasoline in a gasoline tank 1 is supplied to a carburetor 4 through a pump 2 and a fuel supply pipe 3, but gasoline is volatile and the volatile gas is harmful to the human body, so the gasoline in the gasoline tank 1 is A vent pipe 7 having a check valve assembly 6 in the middle connects the area above the highest liquid level and the charcoal canister 5, and the charcoal canister 5 and the engine crankcase 8, and the crankcase and the carburetor. 4 are connected by pipes 9 and 10, respectively, and when the internal pressure of the gasoline tank increases due to volatile gas while the vehicle is stopped, the volatile gas pushes open one check valve provided in the check valve assembly and discharges the gas. It flows into the canister and is absorbed, and the excess amount is stored in the crankcase and is consumed preferentially by the carburetor when the car starts.

In addition, when the pressure inside the tank is reduced, the gasoline tank deforms and breaks, and because the pressure resistance against negative pressure is low, the amount of gasoline in the tank decreases.
Due to the reduced pressure, the other check valve being assembled opens.
Outside air is taken in from the charcoal canister 5 to return the inside of the tank to normal pressure.

Therefore, the check valve assembly connected to the vent pipe must include two check valves in diametrically opposite directions, one for releasing volatile gases from the gasoline tank and the other for sucking atmospheric air into the gasoline tank. Conventional practical products generally have a complicated structure as shown in Figure 2.

In other words, connection port 1 that connects to the gas tank side
An end wall 14 having a connection port 13 for connecting to the canister side is fixed to the open end of a cup-shaped barrel 12 having a mushroom valve 15 inside the partition wall 16'.
An operating cylinder 16 with an H-shaped cross section and a cylindrical valve 17 attached to the
The cylinder frame 18 with the
8 and press the end of the cylindrical valve 17 against the inner surface of the end wall 14 with the coil spring 19 so as to surround the inner end of the connection port 13. This increases the internal pressure of the gasoline tank and removes volatile gas from the partition wall 16'. Always mushroom valve 1
The end of the cylindrical valve 17 that is pressed against the inner surface of the end wall 14 is compressed by the coil spring 19 when the tank becomes negative pressure. The part is the end wall 14
Air flows away from the canister side through the gap between the end of the cylindrical valve and the end wall 14, returning the inside of the gasoline tank to normal pressure.

Therefore, the structure is complicated and it takes a lot of effort to assemble, and there are problems with the accuracy of the coil spring and the length of the valve is long in the axial direction, so it is difficult to make it compact and lightweight.

The present invention was developed with the aim of eliminating the drawbacks of the above-mentioned conventional methods, and will be explained below with reference to the illustrated embodiments.

A fitting part 2 which has pipe connection ports 21 and 22 respectively, and the outer periphery of one is fitted into the inner periphery of the other and fixed.
A set of two housing members 2 having 3 and 24
5, 26, and two check valves 2 coaxial and opposite in direction.
7 and 28 and is fixed within the fitting portion at right angles to the valve shaft;
The cylindrical portion of the other housing member 26 is inserted inside the cylindrical portion extending in the direction of the valve axis from the outer edge of the wall perpendicular to the valve axis, and a male and female fitting holding device is provided in an annular manner on the fitting surfaces of both. The devices 30 and 31 are combined and fixed, and are attached so as to cover the outer periphery of the support plate 29, and along with the support plate in a position perpendicular to the valve shaft, along the inner periphery of the cylindrical portion of the one housing member 25. The seal ring 29' pushed into the
Narrow pressure is formed between the inner periphery of the cylindrical portion and the outer periphery of the support plate, and the wall and the other housing member 26
The fitting and holding devices 30 and 31 are located at positions where they can be appropriately compressed with respect to the edge of the cylindrical portion.

One of the two check valves 27 is a beak-shaped check valve consisting of a closed lip provided at one end of a valve cylinder 32 made of synthetic rubber, etc., and the other check valve 28 is a beak-shaped check valve consisting of a closed lip provided at one end of a valve cylinder 32 made of synthetic rubber or the like. This is an umbrella-shaped check valve consisting of a flexible umbrella-shaped part formed in a folded shape at the other end.

For this purpose, a mounting hole for penetrating the valve cylinder 32 is provided in the support plate 29, and the valve cylinder 32 is pushed from the beak-shaped check valve 27 into the mounting hole, and the umbrella-shaped check valve 2 at the other end is inserted into the mounting hole.
At the same time, one or more ventilation holes 33 are provided around the mounting hole, that is, in the area covered by the umbrella-shaped check valve 28. I will open it and leave it there.

An annular groove 32' matching the inner diameter of the mounting hole is provided on the outer periphery of the valve barrel 32, and the valve barrel is pushed into the mounting hole as described above, so that the periphery of the umbrella check valve 28 comes into contact with one side of the support plate. When in contact, it is preferable that the annular groove 32' engages the edge of the mounting hole to hold the valve barrel 32 axially relative to the support plate.

In this embodiment, the beak-shaped check valve 27 projects into the housing member 25, and the periphery of the umbrella-shaped check valve 27 extends from the support plate 25.
9 in resilient contact with the surface facing the housing member 26.

Therefore, by connecting the connection port 21 to the gasoline tank and the connection port 22 to the canister to the vent pipe 7, if the internal pressure of the tank increases, volatile gas will push open the umbrella-shaped check valve 28 through the vent hole 33. When the pressure inside the tank becomes negative, the lip of the beak-shaped check valve 27 is opened to return the tank to normal pressure.

In addition, if the connection is reversed and the internal pressure of the tank increases, the volatile gas will push open the lip of the beak-shaped check valve and flow into the canister, and when the pressure inside the tank becomes negative, the umbrella-shaped valve 28 will be turned over and air will flow out. Incorporate Each check valve 2
7 and 28 determine how high the internal pressure of the gasoline tank should be to allow volatile gas to flow into the canister, or how much negative pressure should be needed to allow outside air to be taken into the tank.The elasticity and wall thickness should be adjusted accordingly. It is necessary to define

This reduces the number of parts and makes manufacturing easy.
It is possible to provide a check valve assembly that does not take much time to assemble and is short in length and compact.

The airtight seal ring at the fitting part of both housing members has three functions: blocking the inside of the housing from the outside air, blocking the space inside the housing on both sides of the support plate, and fixing the support plate, increasing the simplification effect. . Even if the check valve is replaced with another known check valve, the effects of the present application will not change.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram of an example of the use of the check valve assembly; Figure 2
The figure is a sectional view of a conventional check valve assembly; FIG. 3 is a sectional view of an embodiment of the present invention; In the figure, 23 is an outer fitting part, 24 is an inner fitting part,
25 and 26 are housing members, 27 and 28 are check valves, 29 is a support plate, 32 is a valve cylinder, and 33 is a vent hole.

Claims (1)

[Claims for Utility Model Registration] A set of two housing members, each having a pipe connection port and a fitting portion in which the outer periphery of one is fitted into the inner periphery of the other and fixed; It is comprised of a support plate that supports two check valves that are coaxial and opposite in direction and is fixed in the fitting part at right angles to the valve shaft, and the fitting part is attached to the valve shaft of one housing member. The cylindrical portion of the other housing member is inserted into the cylindrical portion extending in the valve axis direction from the outer edge of the right-angled wall, and the male and female fitting and holding devices provided annularly on the fitting surfaces of both are coupled. The seal ring is mounted to cover the outer periphery of the support plate and is pushed along the inner circumference of the cylindrical portion of the one housing member together with the support plate in a position perpendicular to the valve shaft. The fitting is placed in a position where the inner periphery of the cylindrical portion and the outer periphery of the support plate are compressed, and the wall and the edge of the cylindrical portion of the other housing member are appropriately compressed. A check valve assembly comprising a retaining device.