JP2555223Y2 - Gas-liquid separation chamber of fuel tank - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas-liquid separation chamber of a fuel tank, and more particularly to a fuel tank improved so that leakage of liquid fuel into a canister device can be prevented without increasing the volume. The present invention relates to a gas-liquid separation chamber.

[0002]

2. Description of the Related Art In a fuel tank for an automobile, it is necessary to guide an evaporative gas out of the tank when the internal pressure of the tank increases. As a means for that, conventionally, an evaporating tube is inserted into the tank from the top of the tank to serve as an outlet for evaporating gas, and the hydrocarbon evaporated from the fuel is adsorbed by the charcoal canister and then discharged to the outside of the vehicle. Is generally adopted.

By the way, in order to prevent the fuel liquid from entering the charcoal canister through the evaporative tube,
The evaporative tube is connected to the gas-liquid separation chamber provided on the upper wall of the fuel tank.However, when the liquid surface tilts during turning and the gas-liquid separation chamber part is immersed below the liquid surface for a long time, There is a possibility that the fuel liquid enters the evaporative tube and flows out to the charcoal canister.

As a structure for preventing such inconvenience, Japanese Patent Publication No. 3-41368 discloses an empty chamber main body for forming a gas-liquid separation chamber fixed to the inner surface of an upper wall of a fuel tank. A structure in which an intake hole for evaporative fuel gas is formed in the side wall of the chamber main body, and a discharge hole for fuel is formed in the bottom wall of the chamber main body, and a float valve made of a material lighter than the specific gravity of the fuel liquid is provided in this discharge hole. Has been proposed.

[0005]

However, according to this, since the vacant chamber body is directly fixed to the inner surface of the fuel tank main body, sealing at the joint between the inner surface of the fuel tank main body and the vacant chamber main body is troublesome. Further, it is preferable that the position of the intake hole for the evaporated fuel gas is provided as high as possible, but this tends to be insufficient, so that the effect of preventing the fuel from entering the main body of the empty room cannot be sufficiently obtained. was there.

The present invention has been devised to solve such disadvantages of the prior art, and a main object of the present invention is to improve the fuel tank so that the gas-liquid separation effect can be further enhanced. To provide a gas-liquid separation chamber.

[0007]

According to the present invention, such an object is achieved by connecting an evaporative tube provided on an upper wall of a fuel tank for storing a liquid fuel and communicating with a canister device outside the fuel tank. The configuration of the gas-liquid separation chamber is changed to a container body formed of a synthetic resin material, an evaporative fuel gas intake hole provided on an upper wall of the container body, and a fuel discharge provided on a bottom portion of the container body. The hole is formed of a material lighter than the specific gravity of the fuel liquid to close the fuel discharge hole in response to the rise of the fuel level, and is engaged with a guide sleeve formed on the bottom wall of the container body. A vertically displaceable float valve body and an upper outer peripheral surface of the container body for engaging an inner periphery of a mounting hole formed in a bracket fixed to the inner surface of the upper wall of the fuel tank with a gap therebetween. With set flanges and resilient claws It is achieved by the stuff.

[0008]

According to this structure, the gas-liquid separation chamber and the float valve can be mounted on the inner surface of the bottom wall of the tank in a sub-assembled state, so that the liquid-tightness of the gas-liquid separation chamber is sufficiently ensured. And the assembling to the fuel tank main body can be simplified.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The construction of the present invention will be described in detail below based on specific embodiments shown in the accompanying drawings.

FIG. 1 is a schematic overall view of a fuel tank to which the present invention is applied. The fuel tank main body 1 is made of a box-shaped body, which is formed by squeezing a steel plate and opened on one side.
Are joined together. A gas-liquid separation chamber 2 according to the present invention is mounted on the inner surface of the upper wall of the fuel tank body 1. An evaporator tube 3 is connected to the uppermost portion of the gas-liquid separation chamber 2, and is in communication with a charcoal canister (not shown) in a known manner.

As shown in FIGS. 2 and 3, the gas-liquid separation chamber 2 is formed by injection molding of a synthetic resin material or the like, and has a container shape whose periphery and upper surface are substantially closed. An evaporative fuel gas intake hole 4 is provided at the center of the upper wall 2a, and a fuel discharge hole 5 is provided at the center of the bottom wall 2b.

A guide sleeve 2d is formed integrally on the outer surface of the bottom wall of the gas-liquid separation chamber 2 along the axial direction.
A float valve 6 made of a synthetic resin material having a lighter specific gravity than gasoline or the like as a liquid fuel is mounted on the inside so as to be movable in the vertical direction.

A flange 7 is formed radially outward on the upper part of the peripheral wall 2c of the gas-liquid separation chamber 2. At a diagonal position of the peripheral wall 2c, a pair of resilient claws 8 that expand upward are formed.

The upper wall 2a of the gas-liquid separation chamber 2
The float valve body holding portion 2e inside the guide sleeve 2d is formed of a member different from the peripheral wall 2c and the outer peripheral portion of the guide sleeve 2d, and is connected to each other with the elasticity of the material itself.

In mounting the gas-liquid separation chamber 2 having the above-described structure to the fuel tank body 1, an assembly of the gas-liquid separation chamber 2 is inserted from above into a mounting hole 10 of a bracket 9 formed by bending a steel plate. What is engaged with the inner peripheral edge of the mounting hole 10 by the flange 7 and the resilient claws 8 may be welded to the inner surface of the upper half of the fuel tank body 1. Then, in this state, the lower half and the upper half of the fuel tank main body 1 are joined to each other to obtain an assembly of the fuel tank main body 1.

Next, the operation of the gas-liquid separation chamber 2 will be described. When fuel is injected into the fuel tank main body 1 and the fuel level rises, the float valve body 6 rises, and the fuel discharge hole 5 of the gas-liquid separation chamber 2 is closed. This allows
Even if the liquid level rises further, the fuel liquid does not flow into the gas-liquid separation chamber 2. This exerts the same effect when the liquid level is inclined when the vehicle turns and the gas-liquid separation chamber 2 is immersed in the fuel liquid.

When evaporative fuel gas is generated on the fuel level,
The fuel evaporative gas enters the gas-liquid separation chamber 2 from the gap between the inner surface of the upper wall of the fuel tank body 1 and the upper wall 2a of the gas-liquid separation chamber 2 and the fuel evaporative gas intake hole 4 of the upper wall 2a of the gas-liquid separation chamber 2. Enters the fuel tank main body 1 via the evaporation tube 3.

When the fuel level is lowered, the float valve 6 is also lowered to open the fuel discharge hole 5, and the fuel that has entered the gas-liquid separation chamber 2 returns to the fuel tank body 1. Since the evaporated fuel gas intake hole 4 is provided in the upper wall 2a of the gas-liquid separation chamber 2, the possibility that the fuel liquid enters the gas-liquid separation chamber 2 due to the rise in the liquid level is extremely low.

[0019]

As described above, according to the present invention, since the gas-liquid separation chamber can be configured as a sub-assembly, the liquid tightness of the gas-liquid separation chamber is improved, and the fuel liquid hardly enters the inside of the gas-liquid separation chamber. Since it can be easily mounted on the inner surface of the bottom wall of the fuel tank main body, a great effect can be achieved in reducing the number of manufacturing steps.

[Brief description of the drawings]

FIG. 1 is a schematic overall view of a fuel tank to which the present invention is applied.

FIG. 2 is an enlarged view of a part II in FIG.

FIG. 3 is a partial cross-sectional view along the line III-III in FIG. 2;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fuel tank main body 2 Gas-liquid separation chamber 2a Top wall 2b Bottom wall 2c Peripheral wall 2d Guide sleeve 2e Float valve body holding part 3 Evaporation tube 4 Evaporated fuel gas intake hole 5 Fuel discharge hole 6 Float valve body 7 Flange 8 9 Bracket 10 Mounting hole

Claims (1)

(57) [Scope of request for utility model registration] 1. A gas-liquid separation chamber provided on an upper wall of a fuel tank for storing a liquid fuel and connected to an evaporator tube communicating with a canister device outside the fuel tank, wherein the gas-liquid separation chamber is formed of a synthetic resin material. A fuel container, an evaporative fuel gas intake hole provided in an upper wall of the container body, a fuel exhaust hole provided in a bottom portion of the container body, and a fuel exhaust hole provided in accordance with a rise in fuel level. A float valve body which is formed of a material lighter than the specific gravity of the fuel liquid so as to be closed, and which is displaceable in a vertical direction by engaging with a guide sleeve formed on a bottom wall of the container body; A fuel, comprising: a flange formed on an upper outer peripheral surface of the container body and a resilient claw to be engaged with an inner periphery of a mounting hole formed in a bracket fixed to an inner surface with a gap therebetween. Gas-liquid separation chamber of tank