JPH067953Y2 - Fuel tank float valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a float valve that regulates the fuel injection amount of a fuel tank, and excessive fuel injection above a design value may occur due to a defective seal of the float valve. Is to prevent.

(Prior Art) A vapor gas escape pipe having a valve seat that is opened at the time of fuel injection or always opened is provided above the inside of a fuel tank, and a float valve that floats with the injection of fuel is provided on the valve seat. There is a structure in which it is seated to prevent vapor gas from escaping, and the amount of fuel injection is regulated to around a design value by the vapor gas compression pressure. However, it is difficult to make the valve sit on the valve seat with buoyancy due to the difference in specific gravity between the fuel and the float valve and completely seal the valve so that it does not escape due to leakage of the fuel vapor.

That is, if there is vapor leakage, the amount of vapor gas in the upper layer of the fuel tank is reduced, the thickness of compression by the injected fuel is reduced, and the liquid surface may be injected more than the designed value. Therefore, the seal must be completely generated. Therefore, as shown in FIG. 4, a ring-shaped rubber valve seat a having a fitting groove b in the peripheral portion is manufactured, and a fitting engagement projection e formed on the valve seat portion of the escape pipe d.
Attempts were made to press fit the engagement groove b into the above-mentioned engagement, but if the engagement projection edge e and the engagement groove b are fitted tightly to each other, the valve seat surface c is distorted and slightly loosened. The fuel vapor having pressure leaked from between the engaging protrusion e and the fitting groove b, and in any case, a safety sealability could not be expected.

(Problems to be solved by the present invention) Except for the above-mentioned drawbacks, the present invention is effective even when the valve portion of the float body cannot be formed into a perfect spherical surface without irregularities or even when the valve seat has some distortion. We are trying to develop a structure that can produce a float valve that can almost completely seal by closing the valve.

(Means for Solving the Problems) The present invention is intended to specifically solve the above-mentioned problems, and the surface of the liquid rises as the fuel is injected into the fuel tank. In a float valve in which the valve portion is closed by press-contacting a valve seat provided on the escape pipe of the fuel vapor and the fuel injection is regulated by the valve closing, the float body 13 has a weight 14 at the bottom and Cavity 2 on top
1 and a spherical surface 20 is provided on the upper surface,
The spherical shape of the float valve 12 including the rubber 23 and the float body 13 is made substantially spherical and the spherical rubber 23 is engaged and covered at a plurality of positions without being attached to the spherical rubber 23. Circumference of valve and float body 1
3 is a float valve of a fuel tank, characterized in that vapor gas can be put in and out of the float valve.

A preferred embodiment of the present invention will be described below.

(Embodiment) FIG. 1 illustrates a configuration in which a fuel vapor escape pipe is provided outside the top of a fuel tank 1. The escape pipe 2 is formed in an upper wall 4 of a valve chamber 3. The valve rod 8 of the valve 7 for opening and closing the first valve seat 6 is passed through the lower surface of the lower wall 5, and the second valve seat 9 constituting the valve seat of the present invention is provided on the side of the valve rod 8 of the lower wall 5. A float valve guide cylinder 10 provided with a fuel inlet / outlet 11 in the lower and side portions is attached to a lower portion of the second valve seat 9, and a float valve 12 is freely floated inside the guide cylinder 10. The float valve 12 has a weight 14 on the bottom surface, a cavity 15 formed on the upper portion, and a generally hemispherical lower body 22 integrally formed with a circular fitting ring 16 on the upper surface, and a fitting to be fitted on the fitting ring 16. Edge 1
7 is formed on the lower surface, and a few short engaging claws 1 are formed upward.
9 is provided with a short cylinder 18, a top surface is provided with a spherical surface 20 and an upper body 24 having a cavity 21 formed therein, and a fitting ring 17 of the lower body 22 is fitted with a fitting edge 17 of the upper body 24. Float body 1 made of resin and fixed with a welding agent
A spherical rubber 23 is coated on the spherical surface 20 of No. 3 without adhering, a valve portion is constituted by the rubber 23, and a skirt 23a that is slightly loosely fitted to the cylinder 18 is provided on the peripheral edge.
The several engaging holes 25 formed in a are slightly loosely fitted in the locking claws 19, and the entire float valve 12 including the rubber 23 of the valve portion and the float body 13 is formed into a spherical shape with a part depressed.

In FIG. 3, a fuel supply gun is inserted to inject fuel into the fuel tank 1, the wire Y is pulled, and the valve 7 is moved to the first valve seat 6
The escape pipe 2 and the fuel tank 1 are separated from each other to communicate with each other.

There is a type of the escape pipe 2 in which the first valve seat 6 is not provided and only the second valve seat 9 is provided as shown by the escape pipe d in FIG. 4, and in this type, the second valve seat 9 is always provided. The present invention can be applied to a type in which the second valve seat 9 is closed only when the liquid level W rises due to fuel injection.

(Operation) When fuel is injected into the fuel tank 1, the float body 13 rises due to the rise of the liquid level W, and the rubber 23 that is the valve portion is brought into pressure contact with the second valve seat 9 to close the valve. Escape tube 2
Makes fuel vapor from escape impossible. The fuel injection continues, and the valve closing of the second valve seat 9 also continues, so that the vapor gas above the liquid surface W is compressed, and the compression makes the fuel injection impossible. This effect is known.

(Effect) In the present invention, a spherical float valve 12 is provided with a weight 14 at the bottom of a float body 13, a cavity 21 is formed above it, a spherical surface 20 is provided on the upper surface, and a spherical rubber 23 is attached to the spherical surface 20. Engage and cover a plurality of edge portions without matching, and make the whole including the spherical rubber 23 and the float main body 13 spherical, so that the peripheral portion of the valve portion constituted by the rubber 23 and the float main body 13 are It is made possible to allow vapor gas to flow in and out between the valve portion 23 of the float valve 12.
Since vapor gas can freely flow in and out of the lower surface of the rubber coating, a spherical bulge is generated, and since the vapor gas layer is on the lower surface, the original elasticity of the rubber can be more flexibly maintained and the valve seat 9 The seat is flexibly deformed to form a close contact conforming to the shape of the valve seat 9, and the valve is held closed by the rubber elasticity, and the rubber 23 as the valve body and the float body 13 are held.
Since the float main body 13 and the rubber 23, which is the valve portion, are formed in a ball shape, the float main body 13 can be formed of metal or resin because they are separately manufactured and integrated by assembling. However, it is easy to prevent rotation due to the flow of the liquid surface, and a weight 14 is provided on the bottom of the float body 13 to prevent free rotation, and the valve portion is deformed or scratched. It has the effect of preventing damage and improving durability.

[Brief description of drawings]

FIG. 1 is a cutaway front view showing a float valve in a vertical section,
FIG. 2 is a perspective view in which a part of the float valve is cut away, and FIG.
The figure is an operation system diagram when the first valve seat 6 and the valve 7 are used together. FIG. 4 is a longitudinal sectional view showing a defect when the rubber valve seat a is tried. 1 ... Fuel tank, 2 ... Escape pipe, 9 ... Valve seat 10 ... Float valve guide tube 12 ... Float valve, 13 ... Float body 23 ... Rubber as valve

Claims (1)

[Scope of utility model registration request] Claim: What is claimed is: 1. A valve part is floated by a liquid surface which rises as fuel is injected into a fuel tank, and a valve portion is brought into pressure contact with a valve seat provided on an escape pipe of the fuel vapor to close the valve. In the float valve, the float body 13 is provided with a weight 14 at the bottom, a cavity 21 is formed above the weight 14, and a spherical surface 20 is provided on the upper surface. The float valve 12 including the rubber 23 and the float main body 13 is formed into a substantially spherical shape by covering a plurality of portions of the valve with the rubber 23 and the float main body 13. A float valve for a fuel tank that allows vapor gas to flow in and out between them.