JP2010105523A - Fuel shut-off valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel shut-off valve 10 reducing contact noises between a float and a guide member in the inner periphery of a case, caused by flow-in/out of a fuel upon oscillation or braking of a vehicle. <P>SOLUTION: This fuel shut-off valve 10 includes a case body 30 forming a valve chamber 30S, and a float mechanism 50 elevatably stored in the valve chamber 30S. The case body 30 includes the guide member 36 protruded from a partition wall 32 in the valve chamber 30S, which is apart from a sidewall 31 by an annular recess 37. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a fuel cutoff valve that is attached to an upper portion of a fuel tank and that opens and closes a connection passage that connects the inside and outside of the fuel tank to cut off communication between the fuel tank and the outside.

  At the top of the fuel tank, there is an evaporative fuel treatment device equipped with a fuel shut-off valve such as a full tank control valve and a cut valve connected to the canister, and each valve opens and closes at a predetermined fuel level. In addition to ensuring ventilation to the outside of the fuel tank, liquid fuel is prevented from flowing out. The cut valve shuts off fuel to the outside at a fuel level higher than the full tank level in order to prevent fuel leakage when the vehicle is tilted or when the vehicle is running slalom. In addition, in addition to the pipe connected to the pipe to the canister, the full tank regulating valve is provided with a pipe connected to the cut valve to simplify the piping by sharing the pipe to the canister. ing.

  The fuel shut-off valve opens and closes the valve by floating and sinking while the float in the valve chamber is guided by the guide member in the valve chamber according to the change in the liquid level in the fuel tank (Patent Document 1). However, there is a problem in that when the float performs a floating operation, the float swings in the radial direction, and contact noise is generated between the float and the guide member.

JP-A-8-105571

  An object of this invention is to provide the fuel cutoff valve which reduces the contact sound with the guide member at the time of float float / sink operation.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

[Application Example 1]
A fuel shut-off valve that is mounted on the upper part of the fuel tank and that opens and closes a connection passage that connects the inside and outside of the fuel tank to cut off communication between the fuel tank and the outside.
A valve chamber that connects the fuel tank and the connection passage, a case body that engages with a bottom plate to form the valve chamber (30S),
A float mechanism which is housed in the valve chamber so as to be movable up and down, and which opens and closes the connection passage by moving up and down according to the liquid level of the fuel tank;
With
The valve chamber includes a guide member that is interposed between the case body and the float mechanism and that elastically deforms in a radial direction by guiding the ascent and descent of the float mechanism.

  When the fuel in the vicinity of the fuel shut-off valve rises and the fuel flows in or when the fuel is subsequently discharged, the float mechanism floats and sinks. At that time, when the float mechanism swings in the radial direction, even if the float mechanism comes into contact with the guide member that guides the float, the contact noise between the float and the guide member can be reduced by elastic deformation of the guide member.

[Application Example 2]
In Application Example 2, a plurality of the guide members protrude downward from a partition wall that is an upper wall of the case body. Since the case is provided with the guide member, it can be formed integrally with the case body, and the configuration can be simplified.

[Application Example 3]
In Application Example 3, a plurality of the guide members protrude upward from the bottom plate. With this configuration, even when the guide member cannot be formed on the case body, the guide member having the same effect as the guide member of the case body can be formed on the bottom plate. Since no guide member is provided on the case body, the uneven thickness is reduced, and deformation of the seal portion due to sink marks after resin molding can be prevented.

[Application Example 4]
In Application Example 4, the guide member is supported on the side surface of the float mechanism, and a plurality of the guide members protrude in the axial direction apart from the side surface of the float mechanism. By providing the guide member in the float mechanism, the guide member is positioned on the outermost periphery of the float main body, so that the sliding portion of the guide member contacts the inner wall of the case main body. Since the performance of the float mechanism is determined by the mass, it is necessary to adjust the mass without changing the outer diameter of the float mechanism that needs to slide. The mass of the float mechanism can be adjusted without changing the outermost diameter of the float by changing the mass by cutting the mold at a place other than the guide member.

  In order to further clarify the configuration and operation of the present invention described above, preferred embodiments of the present invention will be described below.

(1) Schematic Configuration of Fuel Tank Ventilation Device FIG. 1 is an explanatory view illustrating a fuel tank ventilation device equipped with a fuel cutoff valve according to an embodiment of the present invention. The fuel tank ventilation device includes a so-called out-tank fuel cutoff valve 10 (full tank regulating valve) and a cut valve COV (valve mechanism) attached to the upper wall of the flat fuel tank FT, a canister CN, And connecting piping for connecting them. The fuel cutoff valve 10 is a valve that is closed when the fuel level in the fuel tank FT reaches the first level FL1 during refueling. The cut valve COV is arranged so as to ensure ventilation to the outside even when the vehicle is inclined, and the fuel level reaches the second level FL2 higher than the first level FL1. A valve that sometimes closes. These valves ensure ventilation to the outside of the fuel tank FT and prevent fuel from flowing out.

  FIG. 2 is a plan view showing the fuel cutoff valve 10, and FIG. 3 is a cross-sectional view taken along line 3-3 of FIG. In FIG. 3, the surface of the fuel tank FT is formed of a composite resin material containing polyethylene, and a mounting hole FTb is formed in the tank upper wall FTa. A fuel shut-off valve 10 is attached to the tank upper wall FTa in a state where the lower part thereof enters the attachment hole FTb.

(2) Configuration of Each Part of Fuel Shutoff Valve 10 The fuel cutoff valve 10 includes a casing 20, a float mechanism 50, and a spring 58 as main components. The casing 20 includes a case main body 30, a shielding plate 35, a lid body 40, and a bottom plate 45. A space surrounded by the lower portion of the case main body 30 and the bottom plate 45 is a valve chamber 30S. A float mechanism 50 supported by a spring 58 is accommodated in the chamber 30S. In addition, an external communication chamber 40S is provided above the valve chamber 30S, and a shielding plate 35 is disposed in the external communication chamber 40S.

  FIG. 4 is an exploded sectional view of the fuel cutoff valve 10. The case main body 30 is formed by a side wall portion 31 and a partition wall 32 formed substantially at the center of the side wall portion 31, and a space below the partition wall 32 is formed in the valve chamber 30S together with the lid 40. Is the external communication chamber 40S. A flange 33 projects in the radial direction from the upper portion of the side wall 31, and a joint 34 is formed upward from the outer periphery of the flange 33. The upper surface of the flange 33 is a portion that welds the outer peripheral portion of the shielding plate 35, and the joint portion 34 is a portion that is welded to the lid body 40. Further, an engagement hole 31 a is formed in the lower portion of the side wall portion 31. The engagement hole 31a is for attaching the bottom plate 45 as will be described later.

  Further, a plurality of (for example, four or eight) guide members 36 for guiding the float mechanism 50 on the inner peripheral side of the side wall portion 31 are integrally directed downward from the partition wall 32 to have a predetermined interval in the circumferential direction. It is projecting at. The guide member 36 is formed apart from the side wall portion. A protruding portion from the partition wall 32 of the guide member 36 is a base portion 38 that is integrated with the side wall portion 31. A float mechanism 50 described later is accommodated in the guide member 36 so as to slide.

A passage forming projection 32a projecting downward is formed at the center of the partition wall 32, and a connection passage 32b connected to the valve chamber 30S is formed through the passage formation projection 32a. . The valve chamber 30S side of the connection passage 32b is an annular seal portion 32c.
An engaging claw 45 a that engages with the engaging hole 31 a of the case main body 30 is formed on the side of the bottom plate 45. When the engaging claw 45a is engaged with the engaging hole 31a, the bottom plate 45 is mounted so as to close the lower opening of the case body 30. A cylindrical projection 45b is formed at the center of the bottom plate 45, and a spring support 45c is formed on the outer periphery thereof. The spring support portion 45 c mounts the spring 58 and supports the spring 58 between the inner lower surface of the float mechanism 50. Further, the bottom plate 45 is formed with four communication holes 45d (one in the drawing) so as to surround the protrusion 45b. The communication hole 45d communicates the fuel tank FT and the valve chamber 30S.

  FIG. 5 is a perspective view showing the shielding plate 35. The shielding plate 35 has a disc-like shape and includes a shielding plate main body 35a inclined toward the central portion. The outer peripheral portion thereof is a holding end 35b welded to the flange 33, and the central portion has a circular protrusion. It is part 35c. The circular protrusion 35c serves as a knob for assembling the fuel cutoff valve 10 and also serves to return the fuel splashed through the connection passage 32b. A vent hole 35d is formed on the outer peripheral side of the circular protrusion 35c. The vent hole 35d has an arc shape with a predetermined width, that is, is formed over almost a half circumference at a place excluding the holding end 35b and the circular protrusion 35c. Further, a barrier 35e is erected on the shielding plate body 35a along the radial end of the vent hole 35d. The barrier 35e is formed to be inclined toward the vent hole 35d as it goes upward, and acts to direct liquid fuel or fuel droplets toward the vent hole 35d, as will be described later.

In FIG. 4, a lid body 40 includes a lid body 41, a first tubular body portion 42 projecting laterally from the center of the lid body 41, and a second tube disposed at right angles to the first tubular body portion 42. The body part 43 (refer FIG. 2) and the flange 44 formed in the outer periphery of the lid | cover main body 41 are provided, and these are integrally formed. A first pipe line 42a is formed in the first pipe body part 42. One end of the first pipe line 42a is connected to the external communication chamber 40S, and the other end is cut through the pipe to the cut valve COV (FIG. 1). It is connected to the. Moreover, in the 2nd pipe part 43, the 2nd pipe line 43a with a larger passage area than the 1st pipe line 42a is formed in the orthogonal direction (refer FIG. 2), and one end of the 2nd pipe line 43a is It is connected to the external communication chamber 40S, and the other end is connected to a canister (FIG. 1) through a pipe line. Here, the passage from the connection passage 32b to the second pipeline 43a is blocked by the shielding plate 35 as shown at P1 in FIG. 5, bypasses the vent hole 35d, and connects to the canister around the circular protrusion 35c. Connected to the second conduit 43a. Further, the passage from the first pipeline 42a to the second pipeline 43a is blocked by the barrier 35e as shown in P2, and is connected to the second pipeline 43a around the circular protrusion 35c. Yes.
Further, an outer welded portion 44 a that is welded to the tank upper wall FTa of the fuel tank FT is formed at the lower end portion of the flange 44.

The float mechanism 50 includes a float 51 and a rubber seal member 55 attached to the top of the float 51. The float 51 includes a float body 52 having a buoyancy chamber 51 </ b> S that is opened downward and divided into a plurality of parts, and a valve support 53 that protrudes from the upper center of the float body 52. The float main body 52 has an upper chamfered portion 59d at the upper portion and a lower chamfered portion 59e at the lower portion. The valve support 53 includes a support base 53a that protrudes in a columnar shape from the center of the float 51, and a retaining part 53b that extends from the top of the support base 53a.
The seal member 55 includes an attachment portion 56 having an attachment hole 56a, and a seal portion 57 formed in a disc shape on the outer peripheral portion of the attachment portion 56, and these are integrally formed of a rubber material. With this configuration, the attachment hole 56 a of the attachment portion 56 is inserted into the support base portion 53 a and is prevented from being removed by the retaining portion 53 b, so that the seal member 55 is supported by the valve support portion 53.
The float 51 is supported by a spring 58 that spans between the upper surface of the buoyancy chamber 51 </ b> S of the float 51 and the spring support portion 45 c of the bottom plate 45.

(3) Operation of the fuel cutoff valve 10 Next, the operation of the fuel cutoff valve 10 will be described. As shown in FIG. 3, when fuel is supplied to the fuel tank FT by refueling, the fuel vapor in the upper part of the fuel tank FT hits the valve chamber 30S, the connection passage 32b, and the shielding plate 35 and then bypasses the vent hole 35d, It escapes to the canister side through the external communication chamber 40S and the second conduit 43a. When the fuel level in the fuel tank reaches the predetermined first level FL1, the fuel closes the communication hole 45d, thereby increasing the tank internal pressure in the fuel tank FT. With this rise in tank internal pressure, an auto-stop is activated to stop refueling of the fuel gun. In this state, the differential pressure between the tank internal pressure and the pressure in the valve chamber 30S increases, and the fuel level rises in the valve chamber 30S. When the fuel level in the valve chamber 30S reaches a predetermined height, the former is caused by a balance between the buoyancy of the float mechanism 50 and the upward force due to the load of the spring 58 and the downward force due to the weight of the float mechanism 50. When the pressure exceeds the latter, the float mechanism 50 is raised, and the seal portion 57 of the seal member 55 is seated on the seal portion 32c to close the connection passage 32b. Thereby, at the time of refueling to the fuel tank FT, it is possible to escape the fuel vapor from the fuel tank FT and to prevent the fuel from flowing out of the fuel tank FT.

(4) Actions and effects of the embodiment The following actions and effects are exhibited by the configuration of the above embodiment.
(4) -1 When the fuel level in the fuel tank FT exceeds the predetermined first liquid level FL1 that closes the communication hole 45d due to refueling, the tank internal pressure of the fuel tank FT rises, so that an automatic stop can be activated. .

(4) -2 Also, when the vehicle turns or brakes, even if the liquid level in the vicinity of the fuel shutoff valve 10 rises and liquid fuel or fuel droplets flow out of the connection passage 32b, the discharged fuel is connected. The light is returned to the shielding plate 35 disposed opposite to the passage 32b. Moreover, the vent hole 35d of the shielding plate 35 is formed at a position that does not face the connection passage 32b, that is, is formed so as to bypass the connection passage 32b to the second conduit 43a. The liquid fuel and fuel droplets are prevented from flowing out from 43a.

(4) -3 As shown in FIG. 6, the first pipe line 42a is connected to another cut valve COV (FIG. 1), and vents the canister through the external communication chamber 40S and the second pipe line 43a. Secured. When liquid fuel or fuel droplets from the cut valve COV flow out of the first pipe line 42a, the barrier 35e formed on the shielding plate 35 is blocked from flowing into the second pipe line 43a, and then into the second pipe line 43a. Bypass the passage that leads to. Therefore, the liquid fuel etc. which flowed out from the 1st pipe line 42a do not go directly to the 2nd pipe line 43a.

(4) -4 The barrier 35e is disposed so as to incline so that the liquid fuel or the fuel droplets flowing out from the first pipe line 42a are directed to the valve chamber 30S through the vent hole 35d. When the hit fuel hits, the amount of fuel flowing out toward the vent hole 35d can be further reduced.

(4) -5 Since the circular protrusion 35c of the shielding plate 35 is disposed at a position facing the connection passage 32b, the liquid fuel and the fuel droplets flowing out from the connection passage 32b are returned to the valve chamber 30S to the outside. Prevent spillage.

(4) -6 As shown in FIGS. 5 and 6, the shielding plate main body 35a of the shielding plate 35 has a slope inclined from its outer periphery toward the vent hole 35d, and therefore, within the external communication chamber 40S. The condensed liquid fuel is quickly returned to the fuel tank FT through the vent hole 35d without stagnation.

(4) -7 Even if the liquid fuel flows into and out of the valve chamber 30S due to turning or swinging of the vehicle and the float mechanism 50 swings in the radial direction toward the case body 30 and contacts the guide member 36, the guide Since the member 36 is spaced apart from the side wall portion 31 and protrudes downward from the partition wall 32, the guide member 36 is easily elastically deformed, and the contact noise can be reduced.

B. Second Embodiment FIG. 7 is a cross-sectional view showing a fuel cutoff valve 10B according to a second embodiment. FIG. 8 is a perspective view showing the bottom plate 45B.
The second embodiment differs from the first embodiment of FIG. 3 in the position of the guide member 46. The guide members 46 are arranged at four positions between the communication holes 45d arranged on the circumference, and project upward from the bottom plate 45B so as to be separated from the inner circumference of the case main body 30B. The float mechanism 50 is accommodated inside the circumference where the guide member 46 is arranged so as to slide with the guide member 46. With this configuration, even when the float mechanism 50 floats and sinks, swings in the radial direction, and violently contacts the guide member 46, the guide member 46 is elastically deformed and contacted because the guide member 46 is supported at one point by the bottom plate 45B. Sound can be reduced. Since the guide member 36 is not provided in the case main body 30B, the uneven thickness is eliminated, and deformation of the seal portion 32c due to sink marks after resin molding can be prevented.

C. Third Embodiment FIG. 9 is a cross-sectional view showing a fuel cutoff valve 10C according to a third embodiment. FIG. 10 is a perspective view showing the float mechanism 50C.
The third embodiment also differs from the first embodiment of FIG. 3 in the position of the guide member 59. The guide member 59 includes a root portion 59a and a sliding portion 59b. The root portion 59a protrudes from the side surface of the upper portion of the float main body 52 in the outer diameter direction by one point support, and the sliding portion 59b is spaced apart from the float main body 52 from the distal end portion of the root portion 59a. It is extended toward. The extending portion is chamfered to form a chamfered portion 59c. The float mechanism 50C having the guide member 59 is accommodated in the case body 36C so as to slide. Similar to the first embodiment, the float mechanism 50C includes a float 51C including a float body 52C and a seal member 55. By providing the guide member 59 in the float mechanism 50, the sliding portion 59b on the outermost periphery of the float main body 52C comes into contact. Therefore, by changing the shape other than the guide member 59, the outermost diameter of the float is not changed. In addition, the mass of the float mechanism 50C can be adjusted, and productivity can be improved. Moreover, since the base part which is hard to bend is chamfered, the sliding part 59b easily hits the inner wall of the case body 30C and is easily elastically deformed.

(1) The present invention is not limited to the above-described embodiments, and can be implemented in various modes without departing from the gist thereof. For example, the following modifications are possible.
The fuel cutoff valve 10 of the above embodiment has been described with respect to the configuration in which the float mechanism is raised by the fuel introduced by the siphon phenomenon into the valve chamber when the fuel level reaches the lower end of the fuel cutoff valve 10. Alternatively, the float may be raised or lowered according to the liquid level in the valve chamber according to the liquid level in the fuel tank.

(2) Although the root portion 59a of the guide member 59 of the third embodiment protrudes from the upper side surface of the float body 52, the root portion 59a projects from the lower side surface of the float body 52 and slides upward. The structure by which the moving part 59b is extended may be sufficient.

(3) In the above embodiment, the guide members (36, 46, 59) are provided only on the case body 30, the bottom plate 45B, and the float mechanism 50C. However, the guide members (36, 46) are provided on both the case body 30 and the bottom plate 45B. , 59), and the like.

It is explanatory drawing explaining the ventilation apparatus of the fuel tank carrying the fuel cutoff valve concerning one Example of this invention. It is a top view which shows the fuel cutoff valve 10 attached to the upper part of the fuel tank of the motor vehicle concerning one Example of this invention. FIG. 3 is a cross-sectional view taken along line 3-3 in FIG. 2. 3 is an exploded cross-sectional view of the fuel cutoff valve 10. FIG. It is a perspective view which shows the shielding board 35. FIG. FIG. 5 is an explanatory diagram for explaining the operation of the fuel cutoff valve 10. It is sectional drawing which shows the fuel cutoff valve 10B concerning 2nd Example. It is a perspective view which shows the baseplate 45B. It is sectional drawing which shows 10 C of fuel cutoff valves concerning 3rd Example. It is a perspective view which shows 50C of float mechanisms.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Fuel cutoff valve 10B ... Fuel cutoff valve 10C ... Fuel cutoff valve 20 ... Casing 30 ... Case main body 30B ... Case main body 30C ... Case main body 30S ... Valve chamber 31 ... Side wall part 31a ... Engagement hole 32 ... Partition wall 32a ... Passage Forming protrusion 32b ... Connection passage 32c ... Seal part 33 ... Flange 34 ... Jointing part 35 ... Shielding plate 35a ... Shielding plate body 35b ... Holding end 35c ... Circular protrusion 35d ... Vent hole 35e ... Wall 36 ... Guide member 37 ... Root Part 40 ... Lid 40S ... External communication chamber 41 ... Lid main body 42 ... First pipe part 42a ... First pipe 43 ... Second pipe part 43a ... Second pipe 44 ... Flange 44a ... Outer welding part 45 ... Bottom plate 45B ... Bottom plate 45a ... Engaging claw 45b ... Projection 45c ... Spring support 45d ... Communication hole 50 ... Float mechanism 50C ... Float mechanism 51 ... Float 5 C ... Float 51S ... Buoyancy chamber 52 ... Float main body 52C ... Float main body 53 ... Valve support 53a ... Support base 53b ... Stopper 55 ... Sealing member 56 ... Mounting portion 56a ... Mounting hole 57 ... Sealing portion 58 ... Spring 59 ... Guide Member 59a ... Root portion 59b ... Sliding portion 59c ... Chamfering portion 59d ... Float upper chamfering portion 59e ... Float lower chamfering portion CN ... Canister FT ... Fuel tank COV ... Cut valve FTa ... Tank upper wall FTb ... Mounting hole

Claims (4)

A fuel cutoff valve that is mounted on the upper part of the fuel tank (FT) and that opens and closes a connection passage (32b) that connects the inside of the fuel tank (FT) and the outside to cut off the communication between the fuel tank (FT) and the outside. ,
A valve chamber (30S) that connects the fuel tank (FT) and the connection passage (32b), a case body (30) that engages with a bottom plate (45) to form the valve chamber (30S),
A float mechanism (50) housed in the valve chamber (30S) so as to be movable up and down, and opened and closed according to the liquid level of the fuel tank to open and close the connection passage (32b);
With
A guide member (36) interposed in the valve chamber (30S) between the case main body (30) and the float mechanism (50) and guiding the ascent and descent of the float mechanism (50) to elastically deform in the radial direction. And a fuel shut-off valve. The fuel cutoff valve according to claim 1,
The said guide member (36) is a fuel cutoff valve which protrudes in multiple numbers toward the downward direction from the partition wall (32) which is an upper wall of the said case main body (20). The fuel cutoff valve according to claim 1,
A plurality of the guide members (36) projecting upward from the bottom plate (45). The fuel cutoff valve according to claim 1,
A fuel cutoff valve, wherein the guide member (36) is supported on a side surface of the float mechanism (50), and a plurality of the guide members (36) are provided protruding in the axial direction apart from the side surface of the float mechanism (50).

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