JP3312226B2 - Check valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a check valve for adjusting a pressure in an automobile fuel tank.

[0002]

2. Description of the Related Art When the pressure in a fuel tank of an automobile becomes abnormally high during long-time high-speed running or long-time parking under high temperature, etc., in order to prevent the fuel tank from expanding, deforming or bursting, It is necessary to release gasoline vapor in the fuel tank to the outside, and conversely, if the pressure in the fuel tank becomes lower than the outside air pressure, then in order to prevent collapse of the fuel tank, Must be introduced into the fuel tank. For this reason, generally, a check valve having a forward / reverse opening / closing valve mechanism is provided on the evaporation line of the fuel tank. Further, when the vehicle turns or falls, it is particularly necessary to prevent the fuel from leaking from the evaporative line to the outside. Therefore, a cut valve for shutting off the evaporative line is generally provided.

[0003]

However, in the prior art, for example, as shown in FIG.
1 and the cut valve 22 are separately formed, the check valve 21 is installed outside the fuel tank 23, and the cut valve 22 is installed separately inside the fuel tank 23. As a whole, it was not only very unreasonable, but also had an adverse effect on cost. In the drawing, reference numeral 24 denotes an evaporative tube connecting the check valve 21 and the cut valve 22, and 25 denotes a canister.

[0004]

SUMMARY OF THE INVENTION A check valve according to the present invention has been devised in view of the above circumstances, and the invention according to claim 1 has a housing installed in the fuel tank and a check valve inside the fuel tank. A discharge passage and an introduction passage for adjusting pressure are independently defined, and a first valve port provided in the discharge passage is urged by a spring force from the outside of the fuel tank toward the inside of the fuel tank. The first sphere is opened and closed by the first sphere, and the first valve port is located on the side of the discharge passage defined independently of the introduction passage and inside the fuel tank with respect to the first sphere. The float body that closes from the opposite direction is vertically movably arranged, and the second valve port provided in the introduction passage is urged by the spring force from the inside of the fuel tank to the outside of the fuel tank. Adopted a configuration that can be opened and closed by two spheres According to a second aspect of the present invention, based on the first aspect, the float body abuts on the first valve port with which the first sphere abuts from the opposite side of the straight line, thereby closing the discharge passage and the first valve port. A configuration is provided in which a concave portion for absorbing the top of the first sphere is provided on the sealing surface that comes into contact with the valve port.

[0005]

According to the present invention, when the pressure in the fuel tank becomes abnormally high under the present invention, the valve opening on the discharge passage side is opened by the internal pressure to release gasoline vapor in the fuel tank. Since the fuel tank is released to the outside, it can prevent the fuel tank from expanding and deforming or bursting. Conversely, when the pressure in the fuel tank becomes lower than the external pressure, the external pressure causes the valve port on the introduction passage side. Opens the valve and introduces outside air into the fuel tank, which can prevent the fuel tank from collapsing and deforming.In addition, when the vehicle turns or falls, the fuel in the fuel tank can be reduced. Once in the discharge passage,
Since the float body automatically rises and closes the valve port of the discharge passage from the opposite direction to the spherical body, the function of preventing fuel leakage can also be exhibited.

[0006]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a check valve according to an embodiment of the present invention; FIG. 1, a discharge passage 2 and an introduction passage 3 for adjusting the pressure in the fuel tank are independently defined, and each of the passages 2
The valve ports 2a and 3a provided in 3 are closed so as to be openable and closable by the spheres 4.5. However, the valve port 2a on the discharge passage 2 side is closed by the sphere 4 from above. When the internal pressure of the fuel tank is received, the sphere 4 moves upward against the spring pressure of the spring 6 to open the valve. Conversely, the valve port 3a on the introduction passage 3 side is lowered by the sphere 5 When the ball 5 is closed and receives an external pressure, the sphere 5 moves downward against the spring pressure of the spring 7 and can be opened.

In the drawing, reference numeral 8 denotes an upper cap mounted on the upper side of the housing 1, 9 denotes a lower cap mounted on the lower side of the housing 1, and 10 denotes a state communicating with the passages 2 and 3. In particular, the lower cap 9 is provided with a through hole 11 for communicating each of the passages 2 and 3 with the inside of the fuel tank.
12 are drilled.

In addition, in this embodiment, in addition to this, a resin float 13 that closes the valve port 2a of the discharge passage 2 from the opposite direction to the above-mentioned sphere 4 can be moved up and down. In addition, a configuration is also adopted in which the float body 13 is urged upward by the spring pressure of the spring 14. still,
For the upper seal surface 13a of the float body 13,
A concave portion 15 capable of absorbing the top of the sphere 4 is provided.

Therefore, the check valve according to the embodiment is different from the conventional one and is installed on the upper side in the fuel tank (not shown).
When the pressure in the fuel tank becomes abnormally high, the sphere 4 moves upward by the internal pressure, the valve port 2a on the discharge passage 2 side is opened, and the gasoline vapor in the fuel tank is connected to the connecting cylinder. Since the fuel is discharged from the portion 10 to the outside through the canister, it is possible to effectively prevent the fuel tank from being deformed or ruptured. Conversely, when the pressure in the fuel tank becomes lower than the outside pressure, the sphere 5 is moved downward by the external pressure, the valve opening 3a on the introduction passage 3 side is opened, and the outside air is released from the fuel tank. As a result, the fuel tank can be effectively prevented from being crushed and deformed.

When the fuel in the fuel tank enters the discharge passage 2 through the through hole 11 when the vehicle turns or falls, as shown in FIG.
The spring body 13 automatically raises the float body 13 and immediately closes the valve port 2a of the discharge passage 2 from the opposite direction to the spherical body 4, thereby securely preventing fuel leakage from the fuel tank. You can do it.

That is, in a state where the float 13 is not provided, when the fuel pressure entering the discharge passage 2 exceeds the spring pressure of the spring 6 with respect to the sphere 4, the sphere 4 moves upward and its valve port 2a This causes the fuel to leak from the discharge passage 2. However, if a float 13 that closes the valve port 2 a from the opposite direction to the sphere 4 is provided as in the present embodiment, For example, even if the fuel pressure that has entered the discharge passage 2 exceeds the spring pressure of the spring 6 with respect to the sphere 4, the valve port 2 is closed by the upper seal surface 13 a of the float 13.
Since a can be reliably closed, the function of preventing fuel leakage can be exhibited in addition to the original check function. Therefore, in such a closed state, the closing action of the valve port 2a by the float 13 and the closing action of the valve port 2a by the spherical body 4 are obtained in a double manner from the vertical direction.
It is very optimal for preventing fuel leakage.

The fuel intrusion occurs not only on the discharge passage 2 side but also on the introduction passage 3 side. The valve port 3a of the introduction passage 3 is spring-biased in the same direction as the fuel pressure. There is no fear that fuel will leak when the valve is opened due to the blockage of the sphere 5.

[0013]

As described above, the check valve of the present invention not only has the above-described simple structure, but also has a function of preventing fuel leakage in addition to the original check function of adjusting the pressure in the fuel tank. This eliminates the need for a separate cut valve as in the past, greatly contributing to streamlining the entire tank system and reducing costs. In addition, closing the valve port on the discharge passage side with the spherical body and the float body from opposite directions can guarantee a double sealing effect, so that a more reliable fuel leakage prevention function than ever can be expected. .

[Brief description of the drawings]

FIG. 1 is a sectional view showing a check valve according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a state where the valve has exerted a fuel leakage prevention function.

FIG. 3 is an explanatory diagram illustrating an example of a conventional tank system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Housing 2 Release passage 2a Same valve opening 3 Introductory passage 3a Same valve opening 4 Sphere on discharge passage 5 Sphere on introduction passage 6 Spring 7 Spring 13 Float 14 Spring

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) F16K 24/00 B60K 15/01 F16K 31/18

Claims (2)

(57) [Claims] 1. A discharge passage and an introduction passage for adjusting a pressure in a fuel tank are independently defined in a housing installed in a fuel tank, and a first passage provided in the discharge passage is provided.
The valve port is openably and closably closed by a first sphere urged by a spring force from the outside of the fuel tank toward the inside of the fuel tank, and the first sphere is formed on the discharge passage side defined independently of the introduction passage. A float body which is located inside the fuel tank with respect to the one sphere and closes the first valve port from the opposite direction to the first sphere is vertically movably disposed, while a second valve port provided in the introduction passage is provided. A check valve that is openably closable by a second sphere biased by a biasing force of a spring extending from the inside of the fuel tank toward the outside of the fuel tank. 2. The float body has a first sphere abutting thereon.
The concave portion for abutting against the valve port from the opposite side of the straight line to close the discharge passage and for providing a concave portion for absorbing the top of the first sphere is provided on the sealing surface abutting on the first valve port. The check valve according to 1.