JPH1122573A - Cut valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reliably prevent fuel from spit-back, by opening a through hole in a seal section of a float, and forming a releasing path for evaporated fuel to the through hole in the top of the float, in a cut valve which opens and closes a valve opening of a housing with the float supported such that the float can move vertically. SOLUTION: When fuel is fed through a filler tube and liquid level L of the fuel reaches a given level, a float 12 floats up, a valve opening of a housing 11 is perfectly sealed with a thin-walled sealing section in an upper part of an outer side body 12A. But, even under this condition, a release path 36 formed between the outer side body 12A and an inner side body 12B is held open through a through hole 27 which is formed in the center of the thin-walled sealing section, therefore, evaporated fuel in a fuel tank 1 can be released continuously from a vent tube 3 to the filler tube side via the release path 36. Spit-back of the liquid fuel from the filler tube during refueling can effectively be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in 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, for example, there is one disclosed in Japanese Patent Application Laid-Open No. 7-257204. Although not specifically shown, the conventional cut valve includes a housing fixed above the fuel tank, and a float supported vertically movably in the housing with an urging spring pressure interposed therebetween. The housing has a tapered valve port at the top that communicates with the evaporative fuel outlet passage, and a plurality of through holes at the side to allow the passage of evaporative fuel and liquid fuel. A conical seal portion for opening and closing the tapered valve port is provided.

Accordingly, when fuel is supplied from a filler tube using a refueling gun under a fuel tank in which such a conventional cut valve is installed, in the initial stage, the fuel level in the fuel tank is still at a predetermined level. Because it has not reached the level
Even if the float is urged by the urging spring pressure, it does not float up and opens the tapered valve port of the housing widely, so that the evaporated fuel generated in the fuel tank can escape to the outlet passage side. It becomes possible.

When the fuel liquid level reaches a predetermined level, the float is lifted by the buoyancy and the urging spring pressure from the liquid fuel, and the opening area of the tapered valve port is reduced by its own conical seal portion. While gradually decreasing, the tapered valve port of the housing is completely closed to prevent the filled liquid fuel from flowing into the outlet passage of the evaporated fuel. To detect the full state and end the refueling.

[0005]

However, in the conventional cut valve, the opening of the valve opening is gradually reduced by using the tapered valve opening of the housing and the conical sealing portion of the float. Although the blockage prevents the liquid fuel from being blown back from the filler tube, the tapered valve port is eventually completely closed by the conical seal portion. Then, the fuel itself cannot escape from the fuel tank. For this reason, if, for example, additional refueling is performed thereafter, there is a risk that the liquid fuel will blow back due to the pressure in the fuel tank. Apart from the valve, it is necessary to provide a means for releasing the fuel vapor.

[0006]

SUMMARY OF THE INVENTION The present invention has been developed to effectively solve the problem of the conventional cut valve, and the invention according to claim 1 has a housing and a housing fixed in a fuel tank. A float supported in the housing so as to be movable up and down, the housing has a valve port communicating with a side of an evaporative fuel discharge passage, and the float has a seal portion at an upper portion for opening and closing the valve port of the housing. In the cut valve, a configuration is adopted in which a through hole communicating with the outlet passage is opened in the seal portion of the float, and a release passage for evaporated fuel reaching the through hole is formed above the float.

According to a second aspect of the present invention, based on the first aspect, the seal portion of the float has a thin-walled shape, and a release passage for evaporative fuel is defined on the back side of the thin-walled seal portion.
A configuration is used in which a projection is provided in the release passage at a constant interval in the direction of the thin seal portion.

The invention according to claim 3 adopts a configuration in which a defense wall is provided on the entrance side of the release passage based on claims 1 and 2.

The invention described in claim 4 is based on claims 1 to 3, and adopts a structure in which the inlet side of the release passage allows the evaporated fuel to flow from above the float downward.

According to a fifth aspect of the present invention, there is provided a housing fixed in the fuel tank, and a float supported in the housing so as to be vertically movable, and the housing has a valve port communicating with the outlet passage for the evaporated fuel. A float having a seal portion at an upper portion thereof for opening and closing a valve port of a housing, wherein the float has an outer body having a seal portion at an upper portion thereof for opening and closing a valve port of the housing, and the float is fitted to the outer body. A through hole communicating with the outlet passage at the center of the sealing portion of the outer body, and an evaporative fuel inlet opening at an upper peripheral edge of the outer body to form an upper portion of the outer body. A configuration is adopted in which a release passage for evaporative fuel from the inlet to the through hole is defined between the inner surface and the upper outer surface of the inner body.

Therefore, according to the invention of claim 1, for example,
Even if the valve port of the housing is completely closed by the seal portion of the float, the fuel vapor in the fuel tank can be released from the release passage to the vapor fuel outlet passage through the through hole, so that the conventional fuel tank can be used. As compared with, the return of the liquid fuel can be more effectively prevented.

According to the second aspect of the present invention, since the seal portion has a thin shape, high surface accuracy of the seal portion can be obtained, and even if the thin seal portion is to be deformed,
The presence of the projections can prevent a large deformation of the thin seal portion, so that there is no possibility that the release passage of the fuel vapor is blocked. According to the third aspect of the present invention, by the existence of the defense wall,
It is difficult for liquid fuel to flow into the release passage. Claim 4
According to the invention, the float can be prevented from being lifted by the evaporated fuel by using the inflow direction of the evaporated fuel, so that the float can be operated only by the fuel level.

According to the fifth aspect of the present invention, as in the case of the first aspect, even if the valve port of the housing is completely closed by the seal portion of the outer body constituting the float, the fuel vapor in the fuel tank is not removed. Can be introduced into the release passage from the introduction port, and can escape from the release passage to the outlet passage side of the evaporated fuel through the through hole, so that the fuel can be more effectively prevented from being blown back. In addition to this, since the float is composed of two parts, the outer body and the inner body, it is very easy to define the release passage of the fuel vapor to the float and to make the seal part of the outer body thin.

[0014]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a cut valve according to a preferred embodiment of the present invention; FIG. In order to prevent the liquid fuel from flowing into the outlet passage side of the evaporated fuel at the same time as detecting the liquid level of the fuel at the time, the fuel tank 1 It is developed as a vent cut valve installed at the lower end side of a vent tube 3 which is an outlet passage connected to the tube 2.

Structurally, as shown in FIG. 2, a housing 11 is fixed above the fuel tank 1 via a bracket to be described later, and is vertically movable via a coil spring 13 in the housing 11. Float 12 supported
, The upper and lower caps 14 and 15 of the housing 11 and the rubber seal 16, and 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, and a valve port 17 communicating with the lower end of the vent tube 3 is formed inside the upper opening. An annular groove 18 for mounting the rubber seal 16
And a plurality of locking claws 19 for mounting the upper cap 14 on the corresponding side wall outer surface, and two pairs of shoulder pieces 20 facing the lower side wall outer surface of each of the locking claws 19.
21 are integrally protruded, and the height of one opposing shoulder piece 20 and the other opposing shoulder piece 21 are shifted according to the thickness of the bracket, so that one of the opposing shoulder pieces 20 at a higher position Is provided with a locking concave portion 22 on the lower surface of the.

In addition to this, a large number of inflow holes 23 for allowing the inflow of the evaporated fuel are opened in the opposed upper side wall, and a plurality of locking claws 24 for attaching 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 in parallel at regular intervals.

The float 12 comprises a cylindrical outer body 12A and a cylindrical inner body 12B.
As shown in FIG. 4, the housing 1
A thin-walled sealing portion 26 having a hemispherical shape for opening and closing the first valve port 17 is formed, a through hole 27 communicating with the vent tube 3 is opened at the center of the thin-walled sealing portion 26, and the thin-walled sealing portion 26 is opened. A large number of inlets 28 are opened on the peripheral edge, and an annular defense wall 29 raised one step from each of the inlets 28 is integrally erected on the upper end edge of the outer body 12A, and a plurality of locking windows are provided on the lower side. 30 are formed.

As shown in FIG. 5, the latter inner body 12B has a raised portion 31 having a similar shape to the thin seal portion 26, which is slightly smaller than the thin seal portion 26, and a thin seal portion formed on the top thereof. While two protrusions 32 are provided at predetermined intervals in the direction of 26, a 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 provided in a range from the lower surface to the middle.

Therefore, when the cylindrical inner body 12B is fitted into the cylindrical outer body 12A, as shown in FIG. 6, the locking claws 34 of the inner body 12B engage with the locking windows 30 of the outer body 12A. The inner body 12B and the outer body 12A are integrated with each other, but in such an integrated state of the two bodies 12A and 12B, the inner body 12B and the upper inner surface including the thin seal portion 26 of the outer body 12A are integrated. Between the upper outer surface including the raised portion 31 of the inner body 12B, the release passage 36 for the evaporated fuel having the inlets 28 as inlets and the through holes 27 as outlets is continuously and automatically defined. .

The upper cap 14 attached to the upper part of the housing 11 has the above-mentioned locking claws 19 on its flange wall.
A plurality of locking windows 37 are formed to lock the lower cap 15, an insertion hole 38 through which the lower end of the vent tube 3 is inserted is opened inside, and the lower cap 15 attached to the lower portion of the housing 11 is formed.
Is formed with a plurality of locking windows 39 for locking with the locking claws 24 on its flange wall, and the coil spring 13
A boss 40 holding the lower end of the boss 40 is projected, and a plurality of through holes 41 are formed around the boss 40 to allow the passage of liquid fuel. Also, rubber seal 16
Is inserted into 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 has an insertion hole through which the lower end of the vent tube 3 is inserted tightly. 42 have been established.

Accordingly, 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. And an upper cap 14 on the upper part of the housing 11.
And attach the integrated float 12 to the housing 1
1 while holding the coil spring 13 between the holding groove 35 recessed in the inner body 12 </ b> B of the float 12 and the boss 40 of the lower cap 15. If the lower cap 15 is attached to the lower part of the housing 11 after obtaining the locked state, the whole can be easily assembled.

As shown in FIG. 7, a bracket 50 for fixing the cut valve V to the fuel tank 1 is formed of a metal plate so as to be fixed to the fuel tank 1 side. Is provided, and a pair of slits 52 for inserting the one opposing shoulder piece 20 is provided at an edge of the opposing hole of the insertion hole 51, and a stopper piece 53 is provided near each slit 52. The lock pieces 54 are formed so as to stand up.

For this reason, one of the opposing shoulder pieces 2 at a higher position
0 facing the inside of the slit 52,
When the upper part is inserted into the insertion hole 51 and rotated in a predetermined direction, the locking piece 54 elastically engages with the locking recess 22 provided on the lower surface of the one opposing shoulder piece 20 by the action of the stopper piece 53. And at the same time, cooperate with the other opposing shoulder piece 21 at the lower level to clamp the hole edge of the insertion hole 51 from above and below, so that the housing 11 is connected to the fuel tank via the bracket 50. Fixed to one side.

Therefore, even if the fuel is supplied from the filler tube 2 through the fueling gun (not shown) from the filler tube 2 under the fuel tank 1 provided with the cut valve V of the present embodiment, As shown in FIG. 8, since the fuel level L in the fuel tank 1 has not yet reached the predetermined level, even if the float 12 is biased by the spring pressure of the coil spring 13, the float 12 does not float, By opening the valve port 17 of the housing 11, a large amount of fuel vapor generated in the fuel tank 1 can be released from the many inlet holes 23 of the housing 11 to the vent tube 3 via the valve port 17.

In this case, even if the fuel vapor enters the housing 11 from the through hole 41 of the lower cap 15 and tries to lift the float 12, the main flow of the fuel vapor is established on the side wall of the housing 11. The valve port 1 while colliding with the thin-walled sealing portion 26 having a hemispherical shape of the outer body 12A constituting the float 12 from the inflow hole 23 formed therein.
7, the floating of the float 12 is suppressed by the flow of the evaporated fuel. Further, even if a part of the evaporated fuel is released through the release passage 36, the evaporated fuel is once introduced downward from the inlet 28 into the release passage 36. This also suppresses the floating of the float 12. As a result, it is possible to guarantee that the float 12 operates only at the fuel level L.

When the fuel level L reaches a predetermined level, the float 12 rises by the buoyancy from the liquid fuel and the urging spring pressure, as shown in FIG. The thin sealing portion 26 of the outer body 12A
To completely block the liquid fuel from flowing into the vent tube 3.
Thereafter, the refueling gun detects a full state in the filler tube 2 and ends the refueling.

However, in the present embodiment, even when the valve port 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 drawing, Since the release passage 36 defined between the body 12A and the inner body 12B is open,
A small amount of the fuel vapor in the fuel tank 1 can be continuously released from the vent tube 3 to the filler tube 2 through the release passage 36, though it is small. Therefore, even if additional refueling is performed, blowback of the liquid fuel from the filler tube 2 can be more effectively prevented.

Further, the seal portion 26 of the outer body 12A constituting the float 12 for closing the valve port 17 of the housing 11 has a high height with the valve port 17 due to the positive provision of a thin wall shape. Since the surface accuracy is obtained, the sealing performance is greatly improved, and even if a dimensional variation occurs, the variation is absorbed by its own flexure, and the valve port 1
7 can be completely closed. However, the thin seal portion 26 is provided with a projection 32 provided on the inner body 12B.
By this, the large deformation will be prevented,
With the deformation of the thin seal portion 26, there is no fear that the release passage 36 will be accidentally shut off.

Further, even if the liquid fuel in the fuel tank 1 enters the float 12 through the inflow hole 23 of the housing 11, the inlet 28 of the outer body 12A is protected at the upper side thereof by a higher protection wall 29. Therefore, there is little possibility that the liquid fuel enters the release passage 36 from the introduction port 28. Even if the liquid fuel enters, the liquid fuel travels along the concave groove 33 of the inner body 12B and It will fall below the fuel tank 1 from the through hole 41.

In the above-described embodiment, the vent cut valve provided at the lower end of the vent tube 3 connected to the filler tube 2 is intended. It is needless to say that the present invention is not limited to this and can be used as an evaporative cut valve having a liquid level detecting function installed at the lower end of an evaporative tube connected to the canister, like a conventional cut valve.

[0032]

As described above, according to the present invention, according to the first aspect of the present invention, even if the valve port of the housing is completely closed by the seal portion of the float, the fuel tank in the fuel tank can be closed. Since the evaporated fuel can 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 fuel from being blown back as compared with the conventional one.

According to the second aspect of the present invention, since the seal portion has a thin-walled shape, a high surface accuracy of the seal portion can be obtained. Because it can prevent large deformation of the part,
There is no possibility that the evaporative fuel release passage will be blocked. According to the third aspect of the present invention, liquid fuel does not easily flow into the release passage due to the presence of the defense wall. According to the fourth aspect, the float can be prevented from being lifted up by the evaporated fuel by utilizing the inflow direction of the evaporated fuel, so that the float can be operated only by the fuel liquid level.

Under the fifth aspect, as in the first aspect, even if the valve port of the housing is completely closed by the seal portion of the outer body constituting the float, the fuel vapor introduced into the fuel tank is introduced. Since it is possible to guide the fuel into the release passage from the mouth and to escape from the release passage to the discharge passage side of the evaporated fuel through the through hole, it is possible to more effectively prevent the fuel from being blown back. In addition, since the float is composed of two parts, the outer body and the inner body, it is very easy to define a release passage for evaporative fuel with respect to the float and to make the seal part of the outer body thin.

[Brief description of the 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. 4 (A) is a plan view showing an outer body of the float,
FIG. 4B is a sectional view taken along line CC of FIG. 4A.

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

FIG. 6 is a sectional view showing a state where an outer body and an inner body of the float are integrated.

FIG. 7 is a perspective view showing a bracket.

FIG. 8 is a sectional view of an essential part for explaining an initial state at the time of refueling.

FIG. 9 is a cross-sectional view of a main part illustrating a state where a valve port of a housing is completely closed by a seal portion of a float.

[Explanation of symbols]

 V cut valve 1 Fuel tank 2 Filler tube 3 Vent tube (outlet passage) 11 Housing 12 Float 12A Outer body 12B Inner body 13 Coil spring 14 Upper cap 15 Lower cap 16 Rubber seal 17 Valve port 20 Higher shoulder piece 21 Lower shoulder piece Reference Signs List 23 Inflow hole 26 Thin seal portion 27 Through hole 28 Inlet 29 Protective wall 31 Raised portion 32 Projection 36 Release passage 50 Bracket 51 Insertion hole 52 Slit L Fuel level

Claims (5)

[Claims] 1. A fuel supply system comprising: a housing fixed in a fuel tank; and a float supported in the housing so as to be vertically movable, the housing having a valve port communicating with an evaporative fuel outlet passage. In a cut valve having a seal portion that opens and closes a valve port of a housing at an upper portion, a through hole communicating with the lead-out passage is opened at a seal portion of the float, and a release passage of evaporative fuel reaching the through hole at the upper portion of the float. Cut valve characterized by being defined. 2. The seal portion of the float is formed in a thin-walled shape, a release passage for evaporative fuel is defined on the back side of the thin-walled seal portion, and a predetermined interval is provided in the release passage in the direction of the thin-walled seal portion. 2. The cut valve according to claim 1, further comprising a protruding projection. 3. The cut valve according to claim 1, wherein a protection wall is provided on an entrance side of the release passage. 4. The cut valve according to claim 1, wherein the inlet side of the release passage allows the evaporated fuel to flow downward from above the float. 5. A fuel supply system comprising: a housing fixed in a fuel tank; and a float supported in the housing so as to be vertically movable, the housing having a valve port communicating with a side of a fuel gas outlet passage. In a cut valve having a seal portion that opens and closes a valve port of a housing at an upper portion, the float includes an outer body having a seal portion that opens and closes a valve port of a housing at an upper portion, and an inner body fitted to the outer body. In addition, a through hole communicating with the outlet passage is opened at the center of the seal portion of the outer body, and an inlet for evaporative fuel is opened at the upper peripheral edge of the outer body, and the upper inner surface of the outer body and the upper part of the inner body are opened. A cut valve defined between an outer surface and a release passage for evaporative fuel continuing from the inlet to the through hole.