JPH0424845Y2 - - Google Patents

Description

[Detailed description of the invention] <Industrial application field> This invention relates to a fuel cap attached to the filler neck of a fuel tank in an automobile. This invention relates to a fuel cap equipped with a negative pressure valve that prevents pressure drop within the fuel tank.

<Prior art> Conventionally, this type of fuel cap has been provided with a negative pressure valve to allow air to flow into the fuel tank in order to prevent pressure drop within the fuel tank (Published by Society of Automotive Engineers of Japan). September 30, 1982
(Japanese) "New Automotive Engineering Handbook," Volume 6, pp. 1-44).

<Problem that the invention aims to solve> However, due to the function of this type of cap, when the valve is operated, air must pass through the valve body, and if the air is contaminated with dust, the dust may pass through the valve body. There was a risk that it might adhere to the seal part.

This invention solves the above-mentioned problems, and aims to provide a cap equipped with a negative pressure valve that can significantly reduce the adhesion of dust and the like to the seal portion of the valve body during operation.

<Means for Solving the Problems> The fuel cap according to this invention includes a cylindrical part whose lower part fits into the filler neck of the fuel tank, and a cylindrical part arranged so as to close the inner periphery of the upper part of the cylindrical part so as to prevent the flow of water. a top plate having a passage hole; and a closure having a top plate having a passage hole, and a negative pressure valve that is activated when air flows into the cylindrical part is assembled directly below the passage hole in the top plate. a fitting recess is provided on the inner circumferential surface of the cylindrical part on the upper side of the top plate of the closure, and a dustproof plate is undercut at the outer circumferential end of the fitting recess so as to block the flow passage hole; The dust-proof plate is provided with an inflow hole that allows air to flow into an air flow path formed between the dust-proof plate and the top plate, and at least one of the opposing surfaces of the top plate and the dust-proof plate is formed. A weir plate is formed on one surface to prevent the air flowing from the inflow hole into the air flow path from flowing straight in the direction of the flow path hole.

<Operations and effects of the invention> In the fuel cap according to this invention, the dust-proof plate is undercut into the fitting recess on the inner peripheral surface of the cylindrical part on the upper side of the top plate, thereby preventing air between the top plate and the top plate. A flow path is formed, and a weir plate is formed on at least one of the opposing surfaces of the top plate and the dustproof plate to prevent air flowing into the air flow path from the inlet hole drilled in the dustproof plate. Straight flow toward the channel hole is obstructed.

In other words, even if dust is mixed in the air flowing into the fuel tank from the fuel tank when the negative pressure valve element is activated, when the air passes through the air flow path between the dustproof plate and the top plate, It progresses in a curved manner due to the weir plate.

Therefore, before the air passes through the flow passage hole, most of the dust collides with the inner peripheral surface of the cylindrical part on the upper side of the weir plate or the top plate, falls, and adheres to the seal part of the negative pressure valve. This can be significantly reduced.

Furthermore, in the fuel cap according to this invention, when installing the dustproof plate on the closure, it can be installed simply by undercutting the outer peripheral end into the fitting recess formed on the inner peripheral surface of the cylindrical part of the closure. This makes it easy to assemble the dustproof plate.

Note that the undercut prevention of the dustproof plate allows the dustproof plate to play the role of removing dust when air flows into the negative pressure valve side. Since it only obstructs the straight flow in the direction and there is no need to consider airtightness, the undercut stop does not reduce the dust removal effect.

<Example> Hereinafter, an example of this invention will be described based on the drawings.

The cap of the first embodiment shown in FIG. 1 is a fuel cap 2 screwed onto a filler neck 1 which is open for refueling an automobile fuel tank.
It is.

This fuel cap 2 has a closure 3 made of a synthetic resin material such as polyacetal.
and a disk-shaped shell 10 which is made of a synthetic resin material such as nylon and is attached to the upper part of the closure 3.

The closure 3 includes a cylindrical portion 3a and a top plate portion 3b having a passage hole 6 and arranged so as to close the upper inner periphery of the cylindrical portion 3a. A screw 4 corresponding to the filler neck 1 is provided on the outer periphery of the lower side of the cylindrical portion 3a, a seal ring 9 is mounted on the upper end of the screw 4, and further, on the outer periphery of the upper side of the cylindrical portion 3a, A flange portion 5 is formed on the lower surface of which the seal ring 9 is brought into contact. The flange portion 5 is provided with a predetermined number of elastic fingers 5a that are deformable in the axial direction of the closure 3 and have claw portions 5b projecting upward at their tips.

The shell 10 is undercut secured to the outer periphery of the flange portion 5 of the closure 3, has a grip portion 10a on its upper portion, and has a ratchet convex portion 1 on the back surface of the upper portion that can be engaged with the claw portion 5b of the elastic finger 5a.
A plurality of 0b are formed. Note that the ratchet convex portion 10b and the claw portion 5b are connected to the closure 3 when a torque of more than a predetermined value is applied to the shell 10 in one direction (the direction of rotation in which the fuel cap 2 is screwed onto the filler neck 1). It spins idly and in the opposite direction (fuel cap 2 turns to filler neck 1).
(rotation direction in which the fuel cap 2
This is provided to prevent over-tightening.

Further, an annular spring holding plate 14 is held on the inner periphery of the lower part of the cylindrical portion 3a of the closure 3 by a plurality of holding protrusions 7 formed at predetermined positions. An annular valve body holding plate 12 is disposed with a coil spring 13 that biases upward interposed therebetween.

The valve element holding plate 12 is provided with a rubber valve element 11 that is fitted into a central fitting hole 12a and has a substantially disc shape with a depressed center and a seal lip 11a on the upper surface of the outer periphery. ing.

Then, due to the biasing force of the spring 13, the seal lip portion 11a of the valve body 11 is brought into contact with the periphery of the flow path hole 6 on the lower surface of the top plate portion 3b, thereby sealing the flow path hole 6 of the top plate portion 3b. has been done.

The above configuration is similar to that of a conventional fuel cap of this type.

The fuel cap 2 of this first embodiment has a cylindrical portion 3 on the upper side of the closure top plate portion 3b.
An annular fitting recess 3c is formed in the inner circumferential surface 3d of a, and the dustproof plate 15 is assembled into the fitting recess 3c with its outer circumferential end being undercut. The dustproof plate 15 has rigidity and is arranged parallel to the top plate part 3b, and forms an air flow path between the dustproof plate 15 and the top plate part 3b.

This dustproof plate 15 has a plurality of (four in the illustrated example) air inflow holes 15d formed near its outer periphery, and when assembled to the closure 3, concentrically surrounds the flow passage hole 6 and allows the air to flow in. From hole 15d to channel hole 6
An outer dam plate 15a is formed that obstructs the straight air flow in the direction. At the tip of this outer weir plate 15a, a first narrow flow passage 17 is formed by cutting out a portion that is offset by about 45 degrees from each inlet hole 15d with the flow passage hole 6 as the center.
A is formed, and the other portions are in contact with the upper surface of the top plate portion 3b. Moreover, inside the outer weir plate 15a,
An inner weir plate 15b is formed at a position shifted by about 45 degrees from each first narrow channel 17A to form a second narrow channel 17B similar to the first narrow channel 17A.

In addition, each narrow channel 17A, 17B is connected to the weir plate 15.
It may be formed not on the distal end side but on the proximal end side or in the center of a and 15b.

Therefore, after the fuel cap 2 is attached to the filler neck 1, when the pressure inside the fuel tank decreases by a predetermined amount below atmospheric pressure, the valve body 11 and the valve resist the biasing force of the coil spring 13. The body holding plate 12 is lowered, and the air passing from the lower surface of the outer edge of the shell 10 between the elastic fingers 5a and the flange portion 5 flows from the flow path hole 15d to the air flow path between the dustproof plate 15 and the top plate portion 3b. enter. Then, it passes through the narrow channels 17A and 17B, and then passes through the channel hole 6 and enters the filler neck 1 from between the lower surface of the top plate 3b and the seal lip 11a, eliminating the negative pressure inside the fuel tank. be able to.

At that time, in the air flow path above the top plate portion 3b, which is in front of the seal lip portion 11a of the valve body 11 that closes the flow path hole 6, the outer and inner weir plates 15a,
Since the inflow hole 15b is provided, the inflow hole 15d
The air flowing in from the first narrow passage 17A is prevented from flowing straight in the direction of the flow passage hole 6 by the outer weir plate 15a, and is bent to pass through the first narrow passage 17A. And the first
The air that has passed through the narrow flow path is further passed through the inner weir plate 15.
a, the liquid cannot flow straight in the direction of the channel hole 6, but instead flows in a curved manner and passes through the second narrow channel 17B.

Therefore, even if dust is mixed in the air, most of the dust is removed from the outer and inner weir plates 15a and 1.
5b or the upper cylindrical inner peripheral surface 3d of the top plate 3b
The air collides with and falls, passing through the flow passage hole 6, and the adhesion of dust to the seal lip portion 11a of the valve body 11 can be significantly reduced.

In addition, in this first embodiment, two weir plates 15
Although the dustproof plate 15 is shown in which portions a and 15b are formed,
The number of weir plates may be one or three or more.

In the fuel cap 2 of the first embodiment, when the dustproof plate 15 is disposed on the closure 3,
The dustproof plate 15 can be installed in the fitting recess 3c formed in the inner circumferential surface 3d of the cylindrical portion of the closure 3 by simply undercutting the outer circumferential end thereof, making it easy to assemble the dustproof plate 15.

Note that the undercut prevention of the dustproof plate 15 allows the dustproof plate 15 to perform the role of removing dust when air flows into the negative pressure valve side.
5 to the closure 3, it only obstructs the straight flow of air in the direction of the flow path hole 6, and there is no need to consider airtightness. There is nothing to reduce it.

In addition, in the fuel cap 2 of the first embodiment, the narrow flow path is projected from the dustproof plate 15 and the top plate portion 3
b The one formed by cutting out the tips of the two weir plates 15a and 15b that come into contact with the upper surface is shown, but the fourth and fifth
As in the second embodiment shown in the figure, a plurality of arc-shaped outer weir plates 35a (four in the illustrated example) are formed between the inflow hole 35d and the flow path hole 6, and the outer weir plates 35a and the top plate A first narrow flow path 37A may be formed between the portion 3b and the inner circumferential surface 3d of the cylindrical portion on the upper side. Note that an inner dam plate 35b similar to that of the first embodiment is formed inside the outer dam plate 35a.

When the dustproof plate 35 of the second embodiment is assembled to the fuel cap 2, the inflow hole 3
Since the air flowing in from 5d bends and flows, even if the air is contaminated with dust, the first
Most of the dust is removed in the same manner as in the embodiment, and the adhesion of dust to the seal lip portion 11a of the valve body 11 can be significantly reduced.

Furthermore, in the first embodiment, the narrow channel is protruded from the dustproof plate 15 and abuts on the upper surface of the top plate portion 3b.
Although the two weir plates 15a and 15b are formed by cutting out the tips thereof, when the dustproof plate 55 is assembled to the fuel cap as in the third embodiment shown in FIGS. An annular outer weir plate 55
It is also possible to form the first narrow channel 57A between the lower end of the outer weir plate 55a and the upper surface of the top plate 3b by forming the first narrow flow path 57A so that it does not come into contact with the upper surface of the top plate 3b.
Furthermore, an inner weir plate 55b is formed inside the outer weir plate 55a so as to protrude from the top plate portion 3b so that its upper end does not come into contact with the lower surface of the dustproof plate 55, and between the upper end of the inner weir plate 55b and the lower surface of the dustproof plate 55. The second narrow flow path 57B
can be formed.

When the dustproof plate 55 of the third embodiment is assembled to the fuel cap 2, even if air mixed with dust flows in from the inlet hole 55d, the outer dam plate 55
a and the inner dam plate 55b, the air cannot flow straight in the direction of the flow path hole 6, but is bent and flows into the first
The air passes through the narrow flow path 57A and the second narrow flow path 57B, and even if dust is mixed in the air, most of the dust collides with the outer and inner weir plates 55a and 55b, as in the first embodiment. Since the valve body 11 falls down, it is possible to significantly reduce the adhesion of dust to the seal lip portion 11a of the valve body 11, as in the first embodiment.

Note that the dustproof plate 55 and the top plate portion 3b that form the narrow channels 57A, 57B are members that do not move when they are installed and used, so the narrow channels 57A, 5
7B will always be kept constant.

In addition, the weir plate is made to protrude from the dustproof plate and the top plate,
A narrow channel can also be formed in the middle part.

[Brief explanation of drawings]

Fig. 1 is a sectional view of the fuel cap of the first embodiment of this invention, Fig. 2 is a plan view of the same embodiment with the shell removed, and Fig. 3 is a bottom view of the dustproof plate of the same embodiment. , FIG. 4 is a bottom view of the dustproof plate of the second embodiment, FIG. 5 is a cross-sectional view of FIG. 4, FIG. 6 is a bottom view of the dustproof plate of the third embodiment, and FIG. FIG. 1... Filler neck, 2... Fuel cap, 3... Closure, 3a... Cylindrical part, 3b
...Top plate part, 3c... Fitting recess, 3d... (cylindrical part) inner peripheral surface, 6... Channel hole, 11... Valve body, 1
5, 35, 55... Dustproof plate, 15a, 15b, 3
5a, 35b, 55a, 55b...Weir plate, 17
A, 17B, 37A, 37B, 57A, 57B...
...Narrow flow path.

Claims (1)

[Claims for Utility Model Registration] A cylindrical part whose lower part is fitted into a filler neck of a fuel tank, and a top plate part which is arranged to close the inner periphery of the upper part of the cylindrical part and has a flow passage hole. A fuel cap is provided with a closure installed on the upper side of the top plate of the closure, and a negative pressure valve that is activated when air flows into the cylindrical part is assembled directly below the flow passage hole of the top plate. A fitting recess is provided in the inner circumferential surface of the cylindrical part, and a dustproof plate is undercut at the outer circumferential end of the fitting recess so as to close the flow passage hole. An inflow hole is bored through which air flows into an air flow path formed between the top plate part and the dustproof plate, and at least one of opposing surfaces of the top plate part and the dustproof plate is provided with a A fuel cap characterized in that a weir plate is formed that obstructs the straight flow of air flowing into the air flow path in the direction of the flow path hole.