JP2010281259A - Non-return valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a non-return valve having improved sealability while preventing the horizontal rattling of a valve element. <P>SOLUTION: The non-return valve includes a housing having a flow path, the valve element 3 stored in the housing movably along a liquid flow direction, a spring 5 urging the valve element to be closed, and a ring-shaped elastic sealing member 4 having a flow path opening 41 into which the valve element is fitted when closed. The valve element is pressed at its annular slope 43a against an edge 41 of the flow path opening, when closed. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a backflow prevention valve for preventing a backflow of fluid, and more particularly to a backflow prevention valve suitable for preventing a backflow of fuel in a fuel supply path of a fuel tank.

  Conventionally, the fuel supply path of a fuel tank in an automobile or the like is opened by hydraulic pressure during refueling to allow the fuel to flow into the fuel tank, and closed by spring energization when refueling is stopped. A backflow prevention valve is provided to prevent this. As this kind of backflow prevention valve, for example, a valve body spring-biased in the valve closing direction in the housing, a valve seat having a contact surface perpendicular to the moving direction of the valve body, and a peripheral edge of the valve body And a valve body support piece that opens and closes the valve body by separating or abutting against the valve seat, and is arranged along the peripheral edge of the valve body, and when the valve is closed, the valve body support piece and the valve seat And an elastic seal member that is sandwiched between the two (see Patent Document 1).

JP 2005-226617 A

  By the way, the backflow prevention valve described in the above-mentioned patent document 1 has, in the closed state, a contact surface of the valve seat perpendicular to the moving direction of the valve body and a contact surface of the valve body support piece opposed thereto. Since the elastic seal member is sandwiched between the valve bodies, there is a problem that the valve body is likely to rattle in the lateral direction (that is, the direction perpendicular to the moving direction of the valve body). Further, in the configuration in which the elastic seal member is sandwiched between the contact surface of the valve seat and the contact surface of the valve body support piece as described above, the valve body support piece (elastic seal member) for the valve seat is necessary. There was also a problem that it was difficult to stably secure the pressure contact force.

  The present invention has been devised in view of such problems of the prior art, and provides a backflow prevention valve that prevents the backlash of the valve body in the lateral direction and improves the sealing performance of the valve. With the goal.

  A first invention made to solve the above problems is a backflow prevention valve (1) provided in a liquid supply path (P), in which a flow path is formed, a housing (2), and a liquid in the housing. A valve body (3) accommodated movably along the flow direction, a biasing means (5) for biasing the valve body in the valve closing direction, and a flow path opening (in which the valve body is fitted when the valve is closed) 41), and the valve body is configured to be in pressure contact with the edge (41) of the channel opening with its annular inclined surface (43a) when the valve is closed.

  Further, as a second invention, the elastic seal member has a groove portion (4b) that extends in the circumferential direction on the inner peripheral surface thereof and is compressed by the pressure contact of the valve body when the valve is closed. Can do.

  As a third aspect of the invention, the housing includes a first member (11) that houses the valve body, and a second member (12) that is coupled to the valve closing direction of the first member. The elastic seal portion may be configured to be sandwiched and fixed by the first member and the second member.

According to the first aspect of the invention, since the annular inclined surface of the valve body is pressed against the edge of the flow path opening of the elastic seal member when the valve is closed, the lateral direction of the valve body (that is, in the moving direction of the valve body). As a result, it is possible to prevent the rattling in the vertical direction) and to increase the pressure contact force of the valve body against the elastic seal member (valve seat) to improve the sealing performance of the valve.
In addition, according to the second aspect, since the groove portion of the elastic seal member is compressed by the pressure contact of the valve body when the valve is closed, the adhesion between the valve body and the elastic seal member is increased, and the sealing performance of the valve is further improved. This can be further improved.
According to the third aspect, since the elastic seal member is sandwiched and fixed between the first member and the second member, there is no need to attach a member for fixing the elastic seal member to the housing or the like. It is possible to reduce the number of parts.

The perspective view of the backflow prevention valve which concerns on embodiment Exploded perspective view of a backflow prevention valve according to an embodiment Sectional drawing of the backflow prevention valve in the valve opening state which concerns on embodiment Sectional drawing of the backflow prevention valve in the valve closing state which concerns on embodiment Enlarged sectional view of part X in FIG. An expanded sectional view showing the 1st modification of an elastic seal member An expanded sectional view showing the 2nd modification of an elastic seal member

  A backflow prevention valve 1 according to an embodiment of the present invention is disposed at a downstream end of a fuel supply path P (see FIG. 3) of a fuel tank T of an automobile, and is opened during refueling to enter fuel (gasoline into the fuel tank T). Etc.) and is closed when refueling is stopped to prevent backflow of fuel (including evaporative gas).

  As shown in FIGS. 1 and 2, the backflow prevention valve 1 is housed in a housing 2 in which a flow path is formed and in a housing 2 that can move forward and backward along the fuel flow direction (see arrow A in FIG. 3). The valve body 3, the ring-shaped elastic seal member 4 that functions as a valve seat that receives the valve body 3 when the valve is closed, the compression spring 5 that urges the valve body 3 in the valve closing direction, and the compression spring 5 are supported. The spring support member 6 is mainly composed.

  The housing 2 accommodates the valve body 3, is connected to a fuel discharge pipe 11 that discharges fuel into the fuel tank T, and an upstream side (valve closing direction side) of the fuel discharge pipe 11. And a connecting pipe 12 fixed to the head.

  The fuel discharge pipe 11 has a substantially cylindrical shape, and a plurality of fuel discharge openings 21 are provided on the peripheral wall thereof. A plurality of guide ribs 22 are provided on the inner peripheral surface of the fuel discharge pipe 11 to guide the movement of the valve body 3 along the axial direction. These guide ribs 22 are respectively disposed between adjacent fuel discharge openings 21 so as to be separated from each other in the circumferential direction. A plurality of locking holes 23 are provided on the downstream side of the peripheral wall of the fuel discharge pipe 11, and a plurality of locking claws 24 projecting from the peripheral surface of the spring support member are provided in each locking hole 23. Are respectively locked. Thus, the spring support member 6 is fitted into the downstream opening of the fuel discharge pipe 11. In addition, a plurality of cutout grooves 25 are provided at the lower end of the peripheral wall of the fuel discharge pipe 11, and a plurality of regulating ribs 26 protruding from the peripheral surface of the spring support member 6 are fitted into the cutout grooves 25, respectively. Is done. Thereby, the rotational movement of the spring support member 6 with respect to the fuel discharge pipe 11 is restricted. Further, the reduced diameter portion 27 located on the upper end side of the fuel discharge pipe 11 is provided for connection with the connection pipe 12.

  The connecting pipe 12 has a substantially cylindrical shape, and an upstream part 12a to which a fuel pipe 30 (see FIG. 3) in which a fuel inlet (not shown) is formed is connected, a downstream part 12b connected to the fuel discharge pipe 11, and these It has a flange portion 12c provided between the upstream portion 12a and the downstream portion 12b. A metal collar member 31 for reinforcing the connection portion of the oil supply pipe 30 is fitted inside the upstream portion 12a. The plurality of locking claws 32 projecting from the outer peripheral surface of the downstream portion 12 b are respectively locked in locking holes 33 provided in the reduced diameter portion 27 of the fuel discharge pipe 11. Accordingly, the connecting pipe 12 is connected to the fuel discharge pipe 11 in a state where the downstream part 12 b is fitted inside the reduced diameter part 27 of the fuel discharge pipe 11. Further, the plurality of regulating ribs 34 projecting from the peripheral surface of the downstream portion 12 b are respectively fitted into cutout grooves 35 provided at the upper end of the peripheral wall of the fuel discharge pipe 11. Thereby, the rotational movement of the connecting pipe 12 with respect to the fuel discharge pipe 11 is restricted. As shown in FIG. 3, the connecting pipe 12 is fixed by welding the flange portion 12 c to the resin fuel tank T with the downstream portion 12 b inserted into the opening 36 of the fuel tank T.

  As shown in FIGS. 3 and 4, the valve body 3 has a cross section that is substantially convex in the valve closing direction, and a protrusion 42 that is inserted into the flow path opening 41 of the elastic seal member 4 when the valve is closed. And a shoulder 43 that is formed so as to be continuous with the peripheral edge on the downstream side of the protrusion 42 and press-contacts with the edge 41a of the flow passage opening 41 of the elastic seal member 4 when the valve is closed, and is formed on the downstream side of the shoulder 43. The straight body portion 44 is provided. The protrusion 42 is disposed at the central portion through which the axis of the valve body 3 passes, and has a bell shape or a terrace shape. The shoulder portion 43 has an annular inclined surface 43a that exhibits a rotating curved surface (that is, a curved surface obtained by rotating a line segment or a curve around the axis of the valve body 3). A spring accommodating portion 45 that accommodates one end side of the compression spring 5 is formed on the downstream side of the valve body 3. The other end of the compression spring 5 is fitted into a spring fixing protrusion 6 a formed at the center of the spring support member 6. A plurality of openings 6b are provided around the spring fixing projection 6a.

  The elastic seal member 4 is made of an elastic material such as rubber, and a mounting groove 4 a extending in the circumferential direction on the outer peripheral surface thereof protrudes from the inner peripheral surface of the downstream end of the reduced diameter portion 27 of the fuel discharge pipe 11. The annular projecting piece 51 is fitted. The elastic seal member 4 has a sealing groove 4b that extends in the circumferential direction on the inner peripheral surface thereof and is compressed by the pressure contact of the valve body 3 when the valve is closed. The inner peripheral surface of the flow path opening 41 is formed so as to be substantially continuous with the inner peripheral surface of the connecting pipe 12. The elastic seal member 4 is sandwiched and fixed between the lower end of the connecting pipe 12 (downstream part 12 b) and the upper surface of the annular projecting piece 51 of the fuel discharge pipe 11.

  The housing 2, the valve body 3, and the spring support member 6 constituting the backflow prevention valve 1 are made of a resin material (for example, polyacetal) in consideration of not only mechanical characteristics but also swelling resistance and permeation resistance to fuel. Can be formed.

  In the backflow prevention valve 1 having the above-described configuration, as shown in FIG. 3, the fuel flows in the fuel supply path P in the direction of arrow A when the vehicle is refueled. At this time, the pressure of the inflowing fuel causes the valve body 3 to move downstream from the closed position for closing the fuel supply passage P shown in FIG. 4 to the open position for opening the fuel discharge opening 21 while compressing the compression spring 5. To do. As a result, as shown by the arrow B, the fuel flows from the central protrusion 42 along the peripheral shoulder 43 toward the fuel discharge openings 21 and is discharged into the fuel tank T. The fuel pressure for moving the valve body 3 to the downstream side can be adjusted by changing the shape and size of the protrusion 42.

  On the other hand, when refueling of the automobile is stopped, the valve body 3 returns to the closed position again by the urging force of the compression spring 5, as shown in FIG. At this time, as shown in FIG. 5, the shoulder portion 43 of the valve body 3 comes into pressure contact with the end edge 41 a of the elastic seal member 4, and the sealing groove 4 b is compressed. Thereby, the elastic seal member 4 is elastically deformed so that the end edge 41a is along the annular inclined surface 43a, and is in close contact with the valve body 3.

  As described above, the backflow prevention valve 1 according to the present invention is configured so that the annular inclined surface 43a of the valve body 3 is in pressure contact with the end edge 41a of the flow path opening 41 of the elastic seal member 4 when the valve body is closed. The backlash in the lateral direction (that is, the direction perpendicular to the moving direction of the valve body 3) is prevented, and the pressure contact force of the valve body 3 against the elastic seal member 4 is increased, thereby improving the sealing performance of the valve.

  Moreover, in this backflow prevention valve 1, since the sealing groove 4b of the elastic seal member 4 is compressed by the pressure contact of the valve body 3 when the valve is closed, the adhesion between the valve body 3 and the elastic seal member 4 is increased, and the valve It becomes possible to further improve the sealing performance.

  Further, in this backflow prevention valve 1, since the elastic seal member 4 is sandwiched and fixed by the fuel discharge pipe 11 and the connecting pipe 12, it is necessary to attach a member for fixing the elastic seal member 4 to the housing 2 or the like. However, the number of parts can be reduced.

  FIG. 6 is an enlarged cross-sectional view similar to FIG. 5 and shows a first modification of the elastic seal member 4. Note that matters not specifically mentioned below are the same as those of the elastic seal member 4 shown in FIG.

  As shown in FIG. 6, the elastic seal member 4 is provided with a sealing groove 4b on the outer peripheral surface side that is compressed by the pressure contact of the valve body 3 when the valve is closed. Further, as shown by a two-dot chain line in FIG. 6, the end edge 41 a of the elastic seal member 4 is inclined obliquely downward in the initial state (before deformation). It is set to be larger than the annular inclined surface 43a. Then, the annular inclined surface 43 a is pressed against the end edge 41 a of the elastic seal member 4, whereby the end edge 41 a is elastically deformed along the annular inclined surface 43 a and is in close contact with the valve body 3.

  By configuring the sealing groove 4b and the end edge 41a of the elastic seal member 4 in this way, it is possible to suppress a decrease in sealing performance due to the pressure in the fuel tank. That is, the pressure in the fuel tank acting from the outer peripheral surface side of the elastic seal member 4 acts in the direction in which the end edge 41a of the elastic seal member 4 is pressed by the annular inclined surface 43a.

  FIG. 7 is an enlarged cross-sectional view similar to FIG. 5 and shows a second modification of the elastic seal member 4. Note that matters not specifically mentioned below are the same as those of the elastic seal member 4 shown in FIG.

  As shown in FIG. 7, the elastic seal member 4 does not have the sealing groove 4b as shown in FIG. 5, but its end edge 41a protrudes horizontally from the lower part of the inner peripheral surface toward the inside. ing. Then, the annular inclined surface 43 a is pressed against the end edge 41 a of the elastic seal member 4, whereby the end edge 41 a is elastically deformed along the annular inclined surface 43 a and is in close contact with the valve body 3.

  Thus, there exists an advantage that the manufacture becomes easy by setting it as the structure in which the elastic seal member 4 does not have the sealing groove | channel 4b.

  Although the present invention has been described in detail based on specific embodiments, the above embodiments are merely examples, and the present invention is not limited to these embodiments. For example, the backflow prevention valve housing according to the present invention is not necessarily configured as an independent member, and may be configured as a part of an oil supply pipe, for example.

DESCRIPTION OF SYMBOLS 1 Backflow prevention valve 2 Housing 3 Valve body 4 Elastic seal member 4b Sealing groove (groove part)
5 Compression spring (biasing means)
6 Support member 11 Fuel discharge pipe (first member)
12 Connecting pipe (second member)
21 Fuel discharge opening 27 Reduced diameter part 31 Oil supply pipe 41 Flow path opening 41a Edge 42 Projection part 43 Shoulder part 43a Annular inclined surface 51 Annular projection piece P Fuel supply path (liquid supply path)
T Fuel tank

Claims (3)

A backflow prevention valve provided in the liquid supply path,
A housing in which a flow path is formed;
A valve body accommodated in the housing so as to be movable along the liquid flow direction;
Urging means for urging the valve body in a valve closing direction;
A ring-shaped elastic seal member having a channel opening into which the valve body is fitted when the valve is closed;
The valve body is in pressure-contact with the end of the channel opening with its annular inclined surface when the valve is closed.   2. The backflow prevention valve according to claim 1, wherein the elastic seal member has a groove portion that extends in a circumferential direction on an inner peripheral surface thereof and is compressed by pressure contact of the valve body when the valve is closed. . The housing includes a first member that houses the valve body, and a second member that is coupled to the valve closing direction side of the first member,
The backflow prevention valve according to claim 1 or 2, wherein the elastic seal portion is sandwiched and fixed by the first member and the second member.

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