JP3533555B2 - Cut 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 cut valve installed in a fuel tank of an automobile.

[0002]

2. Description of the Related Art As a conventional cut valve of this type, there is, for example, one disclosed in Japanese Patent Laid-Open No. 7-257204. Although not specifically shown, the conventional cut valve includes a housing fixed above the fuel tank, and a float movably supported in the housing with an urging spring pressure interposed therebetween. The housing has a tapered valve opening that communicates with the evaporative fuel outlet passage side, and a plurality of through holes that allow passage of evaporative fuel and liquid fuel. A conical seal portion that opens and closes the tapered valve opening is provided.

Therefore, when fuel is supplied from the filler tube using the fuel gun under the fuel tank in which such a conventional cut valve is installed, the fuel level in the fuel tank is still at a predetermined level at the initial stage. Because I have not reached the level,
Even if the float is biased by the biasing spring pressure, the float does not float up, and the tapered valve opening of the housing can be greatly opened to allow the evaporated fuel generated in the fuel tank to escape to the outlet passage side. It will be possible.

When the fuel liquid level reaches a predetermined level, the float floats up due to the buoyant force from the liquid fuel and the biasing spring pressure, and the conical seal portion of the float expands the opening area of the tapered valve opening. While gradually decreasing, it completely closes the tapered valve opening of the housing to prevent the full liquid fuel from flowing into the evaporative fuel outlet passage. Detects the full tank condition and finishes refueling.

[0005]

However, in the conventional cut valve, the tapered valve opening of the housing and the conical seal portion of the float are utilized to gradually reduce the opening area of the valve opening. If the valve is closed to prevent the liquid fuel from blowing back from the filler tube, the leopard will eventually be completely closed by the conical seal portion. Then, by itself, the evaporated fuel in the fuel tank cannot escape. Therefore, for example, when additional refueling is performed after that, there is a risk that the liquid fuel may blow back due to the pressure in the fuel tank. Apart from the valve, it is necessary to install a means for releasing the evaporated fuel.

[0006]

The present invention was developed in order to effectively solve the problem of the conventional cut valve. The invention according to claim 1 is a housing fixed to a fuel tank, A float that is movably supported in the housing is provided, the housing has a valve port that communicates with the evaporative fuel outlet passage side, and the float has a seal portion that opens and closes the valve port of the housing. In the valve, a through hole that communicates with the outlet passage is opened in the seal portion of the float, and a release passage for the evaporated fuel that reaches the through hole is defined in the upper portion of the float, and the inlet of the release passage is formed in the seal portion. A configuration is adopted in which it is formed on the periphery and outside the position corresponding to the valve port.

According to a second aspect of the present invention, on the premise of the first aspect, the seal portion of the float is formed into a thin shape, and a release passage for the evaporated fuel is defined on the back surface side of the thin seal portion.
A configuration is adopted in which protrusions are provided in the release passage so as to project at a constant interval in the direction of the thin seal portion.

According to the third aspect of the present invention, on the premise of the first and second aspects, a construction in which a defense wall is provided on the inlet side of the release passage is adopted.

According to a fourth aspect of the present invention, based on the first to third aspects, the inlet side of the release passage has a structure in which the evaporated fuel flows in from the upper side to the lower side of the float.

According to a fifth aspect of the present invention, there is provided a housing fixed to the fuel tank, and a float movably supported in the housing, and the housing has a valve port communicating with the evaporative fuel discharge passage side. In the cut valve, the float has a seal portion for opening and closing the valve opening of the housing in an upper portion, and the float has an outer body having a seal portion for opening and closing the valve opening of the housing in an upper portion and a fitting member for the outer body. The outer body has a through hole that communicates with the outlet passage in the center of the seal portion of the outer body, and evaporates outside the position corresponding to the periphery of the seal portion of the outer body and the valve port. A structure is adopted in which a fuel introduction port is opened and an evaporative fuel release passage that extends from the introduction port to the through hole is defined between the upper inner surface of the outer body and the upper outer surface of the inner body.

Therefore, according to the invention of claim 1, for example,
Even if the valve opening of the housing is completely closed by the seal portion of the float, the vaporized fuel in the fuel tank can escape from the release passage to the vaporized fuel outlet passage side through the through hole. Compared with, the blowback of the liquid fuel can be prevented more effectively.

According to the second aspect of the invention, since the seal portion has a thin shape, a high surface accuracy of the seal portion can be obtained, and even if the thin seal portion is deformed,
The presence of the projection can prevent large deformation of the thin-walled seal portion, so that there is no risk of blocking the vaporized fuel release passage. According to the invention of claim 3, by the presence of the defense wall,
Liquid fuel does not easily flow into the release passage. Claim 4
According to the invention, since it is possible to suppress the float from floating due to the evaporated fuel by utilizing the inflow direction of the evaporated fuel, it is possible to guarantee that the float operates only by the fuel liquid level.

According to the fifth aspect of the present invention, similarly to the first aspect, even if the valve opening of the housing is completely closed by the seal portion of the outer body constituting the float, the evaporated fuel in the fuel tank is Since it is possible to introduce the fuel into the release passage from the introduction port and escape from the release passage to the outlet passage side of the evaporated fuel through the through hole, it is possible to prevent the blowback of the fuel more effectively. In addition to this, it is easy to define the release passage of the evaporated fuel with respect to the float and the sealing portion of the outer body to have a thin shape because the float is composed of two parts, the outer body and the inner body.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to the preferred embodiments shown in the drawings. A cut valve V according to the present embodiment, as shown in FIG. In order to prevent the liquid fuel from flowing into the outlet passage side of the evaporated fuel by detecting the fuel liquid level at the time, and at the same time to prevent the liquid fuel from blowing back from the filler tube 2, the filler in the fuel tank 1 It was developed as a vent cut valve installed on the lower end side of the vent tube 3 which is the outlet passage connected to the tube 2.

Structurally, as shown in FIG. 2, a housing 11 is fixed in the upper part of the fuel tank 1 through a bracket described later, and a coil spring 13 is interposed in the housing 11 so that the housing 11 can move up and down. Float 12 supported
The housing 11, the upper and lower caps 14 and 15, and the rubber seal 16 are provided. The housing 11, the float 12, and the upper and lower caps 14 and 15 are molded products of synthetic resin.

As shown in FIG. 3, the housing 11 has a cylindrical shape, a valve opening 17 communicating with the lower end of the vent tube 3 is formed inside the upper opening, and the valve opening 17 is provided above the valve opening 17. Annular groove 18 for mounting the rubber seal 16
And a plurality of locking claws 19 for mounting the upper cap 14 on the outer surface of the corresponding side wall, and two pairs of shoulder pieces 20 facing the lower side wall outer surface of each locking claw 19 are formed.
・ 21 is integrally projected, and the heights of one of the facing shoulder pieces 20 and the other facing shoulder piece 21 are shifted according to the plate thickness of the bracket, and the one facing shoulder piece 20 at a higher position is provided. The engaging recess 22 is provided on the lower surface of the.

In addition to this, a large number of inflow holes 23 for allowing inflow of evaporated fuel are formed in the opposite side walls near the upper part, and a plurality of locking claws 24 for mounting the lower cap 15 are provided on the outer surface of the lower side wall. In addition, a plurality of guide ribs 25 for guiding the vertical movement of the float 12 in the axial direction of the inner surface of the side wall are arranged side by side at regular intervals.

The float 12 comprises a cylindrical outer body 12A and a cylindrical inner body 12B, and the former outer body 12A.
As shown in FIG. 4, the housing 1 is mounted on the upper side thereof.
The thin-walled seal portion 26 having a hemispherical shape that opens and closes the valve opening 17 of No. 1 is formed, a through hole 27 communicating with the vent tube 3 is opened at the center of the thin-walled seal portion 26, and the thin-wall seal portion 26 is A large number of inlets 28 are provided on the periphery, and an annular defense wall 29, which is higher than the inlets 28, is integrally provided upright on the upper edge of the outer body 12A, and a plurality of locking windows are provided on the lower side. 30 is formed.

Also, as shown in FIG. 5, the inner body 12B of the latter is formed with a raised portion 31 having a shape similar to the thin seal portion 26 on the upper side thereof, and the thin seal portion is formed on the top thereof. The two protrusions 32 projecting at regular intervals in the 26 direction are provided, while the fuel flow-down groove 33 is formed on the opposing outer surface, and the outer body 12A is formed on the lower outer surface.
A plurality of locking claws 34 for locking the locking window 30 are provided, and a holding groove 35 for holding the upper end of the coil spring 13 is recessed in a range from the lower surface to the middle.

Therefore, when the cylindrical inner body 12B is fitted inside the cylindrical outer body 12A, the locking claws 34 of the inner body 12B are fitted in the locking windows 30 of the outer body 12A as shown in FIG. The inner body 12B and the outer body 12A are integrated with each other by being locked. In the integrated state of the two bodies 12A and 12B, the outer body 12A and the upper inner surface including the thin seal portion 26 are integrated. Between the upper outer surface including the raised portion 31 of the inner body 12B, the vaporized fuel release passage 36 having the inlets 28 as the inlets and the through holes 27 as the outlets is continuously and automatically defined. .

The upper cap 14 attached to the upper part of the housing 11 has the locking claw 19 on the flange wall thereof.
Is formed with a plurality of locking windows 37 for locking the lower end of the vent tube 3 and an insertion hole 38 for inserting the lower end of the vent tube 3 is formed therein.
Has a plurality of locking windows 39 for locking the locking claws 24 formed on the flange wall thereof, and the coil spring 13 is formed at the center thereof.
A boss portion 40 that holds the lower end of the boss portion 40 is provided in a protruding manner, and a plurality of through holes 41 that allow passage of the liquid fuel are formed around the boss portion 40. Also, the rubber seal 16
Is to be mounted in the annular groove 18 of the housing 11 via the upper cap 14 in order to ensure the sealing property with the vent tube 3, and an insertion hole for tightly inserting the lower end of the vent tube 3 inside. 42 has been opened.

Therefore, in the cut valve V according to the present embodiment, the locking state of the locking window 37 and the locking claw 19 is obtained while the rubber seal 16 is mounted in the annular groove 18 of the housing 11. The upper cap 14 on top of the housing 11.
Attach the float 12 to the housing 1
1 and the coil spring 13 is interposed between the holding groove 35 recessed in the inner body 12B of the float 12 and the boss portion 40 of the lower cap 15, and the locking window 39 and the locking claw 24 are inserted. When the locked state is obtained and the lower cap 15 is attached to the lower portion of the housing 11, the whole is easily assembled.

The bracket 50 for fixing the cut valve V to the fuel tank 1 is formed of a metal plate material so that it can be fixed to the fuel tank 1 side as shown in FIG. Is provided, and a pair of slits 52 into which the one of the facing shoulder pieces 20 is inserted are provided at the opposite hole edges of the insertion hole 51, and stopper pieces 53 are provided in the vicinity of the respective slits 52. The lock pieces 54 are configured to stand up and be formed.

For this reason, one of the opposing shoulder pieces 2 at the higher position
While facing 0 in the slit 52, the housing 11
When the upper part of the lock piece 54 is inserted into the insertion hole 51 and is rotated in a predetermined direction, the stopper piece 53 restricts the lock piece 54 so that the lock piece 54 is elastically engaged with the engaging recess 22 provided on the lower surface of one of the facing shoulder pieces 20. The upper edge of the insertion hole 51 is pinched in the vertical direction in cooperation with the other lower shoulder piece 21 facing the lower side, so that the housing 11 can hold the fuel tank through the bracket 50. It is fixed to side 1.

Therefore, even under the fuel tank 1 in which the cut valve V of this embodiment is installed, when fuel is supplied from the filler tube 2 through the fuel gun (not shown) at the time of fueling, at the initial stage, As shown in FIG. 8, since the fuel liquid level L in the fuel tank 1 has not yet reached a predetermined level, the float 12 does not float up even if it is biased by the spring pressure of the coil spring 13, By opening the valve port 17 of the housing 11, a large amount of evaporated fuel generated in the fuel tank 1 can be released from the many inflow holes 23 of the housing 11 through the valve port 17 to the vent tube 3 side.

In this case, even if the evaporated fuel enters the housing 11 through the through hole 41 of the lower cap 15 and the float 12 is floated, the main flow of the evaporated fuel is established on the side wall of the housing 11. While colliding with the hemispherical thin-walled seal portion 26 of the outer body 12A constituting the float 12 from the inflow hole 23, the valve opening 1
As a result, the floating of the float 12 is suppressed by the flow of the evaporated fuel. Further, even if a part of the evaporated fuel escapes through the release passage 36, the evaporated fuel will be once introduced downward from the inlet 28 into the release passage 36. This also prevents the float 12 from rising. As a result, the float 12 can be guaranteed to operate only at the fuel level L.

When the fuel liquid level L reaches a predetermined level, the float 12 is lifted up by the buoyancy from the liquid fuel and the biasing spring pressure as shown in FIG. 9, and the valve opening 17 of the housing 11 is opened. The thin seal portion 26 of the outer body 12A
Since it completely blocks the liquid fuel that has become full and the full liquid fuel is prevented from flowing into the vent tube 3,
After that, the refueling gun detects the full state in the filler tube 2 and ends refueling.

However, in the present embodiment, even if the valve opening 17 of the housing 11 is completely closed by the thin seal portion 26 of the outer body 12A of the float 12, as shown in the figure, the outer side is still outside. Since the release passage 36 defined between the body 12A and the inner body 12B is open,
Although a small amount, the evaporated fuel in the fuel tank 1 can be continuously released from the vent tube 3 to the filler tube 2 side via the release passage 36. Therefore, even if additional fuel is supplied, it is possible to more effectively prevent the liquid fuel from being blown back from the filler tube 2.

Further, since the seal portion 26 of the outer body 12A which constitutes the float 12 for closing the valve opening 17 of the housing 11 is positively provided with a thin shape, it is higher than the valve opening 17. Since the surface accuracy can be obtained, the sealing property is greatly improved, and even if a dimensional variation occurs, the variation is absorbed by the bending of the valve itself, and the valve opening 1
We can guarantee that 7 will be completely closed. However, the thin seal portion 26 is provided with the protrusion 32 provided on the inner body 12B.
Therefore, the large deformation is prevented,
The deformation of the thin seal portion 26 never causes the release passage 36 to be accidentally blocked.

Further, even if the liquid fuel in the fuel tank 1 enters the float 12 side through the inflow hole 23 of the housing 11, the inlet 28 of the outer body 12A is protected by a higher defense wall 29 on the upper side thereof. Therefore, the liquid fuel is less likely to enter the release passage 36 from the introduction port 28, and even if the liquid fuel enters, the liquid fuel travels through the concave groove 33 of the inner body 12B and the lower cap 15 of the lower cap 15. It will fall below the fuel tank 1 from the through hole 41.

In the above embodiment, the vent cut valve installed at the lower end of the vent tube 3 connected to the filler tube 2 is targeted, but the present invention is not limited to this. It is needless to say that the present invention can be used as an evaporation cut valve having a liquid level detection function installed at the lower end of the evaporation tube connected to the canister side, without being limited thereto.

[0032]

As described above, according to the present invention, by adopting the above configuration, under the first aspect, even if the valve opening of the housing is completely closed by the seal portion of the float, the inside of the fuel tank Since it is possible to let the evaporated fuel escape from the release passage to the outlet passage side of the evaporated fuel through the through hole, it is possible to more effectively prevent the blowback of the fuel as compared with the conventional one.

According to the second aspect of the present invention, since the seal portion has a thin shape, a high surface accuracy of the seal portion can be obtained, and even if the thin seal portion is deformed, the presence of the protrusion causes the thin seal to be formed. Since it can prevent large deformation of the part,
There is no danger of blocking the evaporative fuel release passage. According to claim 3, the presence of the protection wall makes it difficult for the liquid fuel to flow into the release passage. According to the fourth aspect, since the float can be prevented from floating up by the evaporated fuel by utilizing the inflow direction of the evaporated fuel, it is possible to guarantee that the float operates only by the fuel level.

According to the fifth aspect, like the first aspect, even if the valve opening of the housing is completely closed by the seal portion of the outer body forming the float, the evaporated fuel in the fuel tank is introduced. Since it is possible to introduce it from the mouth into the release passage and to let it escape from the release passage to the lead-out passage side of the evaporated fuel through the through hole, it is possible to prevent the blowback of the fuel more effectively. In addition, because the float is composed of two parts, the outer body and the inner body, it is easy to define the release passage of the evaporated fuel with respect to the float and to make the seal portion of the outer body thin.

[Brief description of drawings]

FIG. 1 is a schematic diagram illustrating an example of use of a cut valve according to an embodiment of the present invention.

FIG. 2 is an exploded perspective view showing the cut valve.

3A is a plan view showing a housing, FIG. 3B is a sectional view taken along line AA of FIG. 3A, and FIG. 3C is a sectional view taken along line BB of FIG. 3A.

FIG. 4A is a plan view showing the outer body of the float,
4B is a sectional view taken along the line CC of FIG. 4A.

FIG. 5A is a plan view showing an inner body of a float,
FIG. 5B is a sectional view taken along the line DD of FIG. 5A.

FIG. 6 is a cross-sectional view showing a state in which the outer body and the inner body of the float are integrated.

FIG. 7 is a perspective view showing a bracket.

FIG. 8 is a sectional view of relevant parts for explaining an initial state during refueling.

FIG. 9 is a cross-sectional view of relevant parts for explaining a state in which the valve port of the housing is completely closed by the seal portion of the float.

[Explanation of symbols]

V cut valve 1 fuel tank 2 Filler tube 3 Vent tube (outlet passage) 11 housing 12 floats 12A outer body 12B inner body 13 coil spring 14 Upper cap 15 Lower cap 16 rubber seal 17 valve 20 high shoulder 21 Lower shoulder 23 Inflow hole 26 Thin-walled seal part 27 through holes 28 Inlet 29 Defense Wall 31 Raised part 32 protrusions 36 release passage 50 bracket 51 insertion hole 52 slits L Fuel level

─────────────────────────────────────────────────── ─── Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) F02M 37/00 F02M 37/00 311 B60K 15/077 F16K 24/04 F16K 31/18

Claims (5)

(57) [Claims] 1. A housing fixed to a fuel tank,
A float that is movably supported in the housing is provided, the housing has a valve port that communicates with the evaporative fuel outlet passage side, and the float has a seal portion that opens and closes the valve port of the housing. In the valve, a through hole that communicates with the outlet passage is opened in the seal portion of the float, and a release passage for the evaporated fuel that reaches the through hole is defined in the upper portion of the float, and the inlet of the release passage is formed in the seal portion. A cut valve which is formed at the periphery and outside the position corresponding to the valve opening. 2. A seal portion of the float has a thin shape, a release passage for evaporated fuel is defined on the back surface side of the thin seal portion, and a constant space is provided in the release passage in the direction of the thin seal portion. The cut valve according to claim 1, further comprising a protrusion that protrudes. 3. The cut valve according to claim 1, wherein a protective wall is provided on the inlet side of the release passage. 4. The cut valve according to claim 1, wherein the fuel vapor is introduced into the release passage from the upper side to the lower side of the float. 5. A housing fixed to the fuel tank,
A float that is movably supported in the housing is provided, the housing has a valve port that communicates with the evaporative fuel outlet passage side, and the float has a seal portion that opens and closes the valve port of the housing. In the valve, the float is composed of an outer body having a seal portion for opening and closing the valve opening of the housing in the upper part, and an inner body fitted and locked to the outer body, and the outlet passage is provided at the center of the seal portion of the outer body. A through hole communicating with the outer body, and an evaporative fuel inlet at the periphery of the seal portion of the outer body and outside the position corresponding to the valve opening. A cut valve, characterized in that a release passage for the evaporated fuel is formed between the outer surfaces, the release passage continuing from the introduction port to the through hole.