JPH0754024Y2 - Fuel tank backflow prevention device - Google Patents

Description

[Detailed description of the device] [Industrial applications]

The present invention relates to a backflow prevention device for a fuel tank, which is provided between the fuel filler port and the fuel tank.

[Prior art]

The backflow prevention device for the fuel tank, which has the function of opening during normal flow of fuel and closing during reverse flow of fuel,
Conventionally, for example, Jitsukai 59-9926, 59-155222, 60-3
As seen in No. 118 etc., the constituent members are valve bodies,
Since the valve body, the rotary shaft pin, and the like are each made of independent parts, the number of parts is large. Further, after the rotary shaft pin is assembled, it is necessary to crush the tip so that the pin does not come off.

[Problems to be solved by the device]

The present invention has made it an object to facilitate the assembling and reduce the number of parts in such a backflow prevention device for a fuel tank, and at the same time, studied a structure in which the valve body is hard to come off and the assembly does not come off from the pipe. It is a thing.

[Means for Solving the Problems]

As a result of various studies by the present inventor, a resin valve body (1) integrally formed with a rotating shaft (2) at a position displaced from the center line.
And a resinous and annular valve body (3) around the outer periphery of the valve body (1), and a bearing portion (4) provided corresponding to the valve body rotating shaft (2) of the valve body (3). The above problem has been solved by developing a backflow prevention device for a fuel tank, which is characterized in that a retaining protrusion (5) is provided on the outer peripheral side of (1). The annular valve body (3) referred to here is provided on the pipe by adding the retaining projection (5) to the bearing portion (4) at a position other than two positions on the outer peripheral side, or by providing a positioning projection (6) on the outer periphery. It is possible to adopt a structure in which the positioning protrusion (6) is fitted to the notch (7), or a protrusion is provided near the bearing portion (4) to form the valve body open stopper (8).

[Action]

The fuel tank backflow prevention device of the present invention, when assembling the valve body (1) to the valve body (3) during manufacture, resists the elasticity of the annular valve body (3) against the up and down arrows in FIG. From the direction to the inner diameter direction (center direction), the distance between the left and right bearing portions (4) and (4) widens, and the rotating shaft (2) protruding left and right of the valve body (1) is fixed to the bearing portion (4) ( 4), and when the force is released, the bearing parts (4) and (4) of the valve body (3) return to their original positions and snap fit to complete the assembly. This completes the device with only two members. Further, by providing the retaining projection (5) on the outer peripheral side of the bearing portion (4) of the valve body (3) that holds the rotating shaft (2) protruding to the left and right of the valve body (1), the valve body (3) ) Regulated the amount of deformation in the inner diameter direction. This prevents the assembly from falling out of the pipe during use.

【Example】

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a front view of a backflow prevention device for a fuel tank according to the present invention, and FIG. 2 is an A- in FIG. 1 when mounted in a pipe.
It is a sectional view corresponding to part A. FIG. 3 is a rear view of the product of the present invention when the valve body is in the open state. FIG. 4 is an overall schematic view of a vehicle fuel tank. As is apparent from FIG. 4, the backflow prevention device (10) for a fuel tank of the present invention is used by being installed in the pipe (23) between the fuel filler port (21) and the fuel tank (22). The valve body (3) is mounted almost vertically so that it opens when the fuel flows toward the tank and closes when the fuel blows back.
The valve body (1) integrally has a rotating shaft (2) at a position displaced from the center line so as to keep the closed state by its own weight. Since the valve body (1) receives pressure from the tank side when closed, rigidity to withstand it is imparted by mechanical strength of synthetic resin, surface ribs, appropriate thickness and the like. The ring-shaped valve body (3) made of synthetic resin holding the valve body (1) on the outer periphery has a bearing portion (4) (4) at a position corresponding to the valve body rotating shaft (2). have. The bearing portion (4) is provided with a plurality of bearing protrusions (9) on the inner peripheral side of the valve body (3) so as to surround the valve body rotating shaft (2). Further, on the inner circumference of the valve body (3), a stopper projection (11) is provided on the rear side and below the axial center so that the valve body (1) can rotate only in one direction.
Similarly, on the rear side, the inner peripheral rib (12) goes downward from the bearing section (4).
And an inner peripheral rib (13) is provided above the bearing portion (4) and on the front side of the shaft center. An open stopper protrusion (8) for restricting further rotation of the valve body (1) opened in the horizontal direction is also provided on the rear side of the shaft center near the bearing portion (4). On the outer peripheral side of the valve body (3), there are provided projections (5) at three locations. Two top retaining projections (5)
(5) is provided corresponding to the rotary shaft (2) provided at a position displaced from the center line of the valve body (1),
In addition to them, another retaining projection (5) is provided at the bottom. A positioning protrusion (6) is provided on the upper periphery of the valve body (3), and the pipe (2
Only by aligning the positioning protrusions (6) with the notches (7) provided in 3), the correct assembly state can be obtained. The other portion of the outer circumference of the valve body (3) is a flange (14), which abuts the end of the pipe (23) to position and close the peripheral portion.

[Effect of device]

As described above, the device for preventing backflow of a fuel tank of the present invention is easy to assemble and the number of parts is reduced, thereby achieving cost reduction. In addition, when the valve body does not easily come off from the assembly and the assembly does not come off from the pipe, and the corrosion resistance is improved, it opens during normal flow when refueling for a long time, and when the fuel flows back Has a good closing function.

[Brief description of drawings]

FIG. 1 is a front view of a backflow prevention device for a fuel tank according to the present invention, and FIG. 2 is an A- in FIG. 1 when mounted in a pipe.
It is a sectional view corresponding to part A. FIG. 3 is a rear view of the product of the present invention when the valve body is in the open state. FIG. 4 is an overall schematic view of a vehicle fuel tank. (1) …… Valve disc, (2) …… Rotating shaft (3) …… Valve body, (4) …… Bearing part (5) …… Prevention projection, (6) …… Positioning projection (7) …… Notch, (8) …… Opening stopper protrusion (9) …… Bearing protrusion, (10) …… Backflow prevention device (11) …… Stopper protrusion, (12) (13) …… Inner peripheral rib (14) …… Flange

Claims (1)

[Scope of utility model registration request] 1. A resin valve body (1) integrally formed with a rotary shaft (2) at a position displaced from the center line of a circle, and a resinous and annular valve body (3) around the outer periphery of the valve body (1). ) And the valve body rotating shaft (2) of the valve body (3)
A backflow prevention device for a fuel tank, characterized in that a retaining projection (5) is provided on the outer peripheral side of a bearing portion (4) provided corresponding to.