JP2011131710A - Fuel cutoff valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable an upper valve element to perform stable lifting operation to a float by performing stable valve closing operation by large buoyancy, in a constitution of the float of a two-stage structure in a fuel cutoff valve. <P>SOLUTION: The fuel cutoff valve 10 has a casing 20 and a float mechanism 50. The float mechanism 50 has the float 51 and the upper valve element 60 liftable to an upper part of the float 51. The float 51 has a valve forming member 54 for dividing a storage chamber 51S into a plurality of pieces. An upper part of the valve part forming member 54 has a storage part 55 having a sub-valve 55d and forming a spring chamber 55S and a partition wall 56 for partitioning a space of an outer wall of the storage part 55 and an inner wall of an upper wall 52 and a sidewall 53. The partition wall 56 is partitioned into an air chamber 56Sa closed in an upper part and a communicating chamber 56Sb opened in an upper part via a claw inserting cutout 56a formed adjacent to an engaging part 52b. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a fuel cutoff valve that is mounted on an upper portion of a fuel tank and that cuts off the communication between the fuel tank and the outside according to the fuel level in the fuel tank.

  Conventionally, patent document 1 etc. are known as this kind of a fuel cutoff valve. The fuel shut-off valve is mounted on the upper part of the fuel tank, and is moved up and down by increasing / decreasing buoyancy in the valve chamber of the casing provided with a connection passage connected to the outside (canister) and the valve chamber of the casing. The float and the upper valve body mounted on the upper part of the float are provided. As the fuel level in the fuel tank rises, the float increases buoyancy, and the upper valve body rises integrally with the float, thereby closing the connection passage and preventing the fuel from flowing out. In such a fuel cutoff valve, when the passage area of the connection passage is large, if the connection passage is directly opened and closed by a float, the float is adsorbed and opened again, so-called reopening valve characteristics are not good, so a small passage area It has a two-stage valve structure provided with an upper valve body having a passage. Such a support mechanism and engagement mechanism for the upper valve body and the float form a sliding recess formed by hollowing out the upper portion of the float, and the engaging claw protruding from the lower portion of the upper valve body is accommodated in the sliding recess. In this way, the engagement claw is engaged with the upper part of the float.

  However, the support mechanism and the engagement mechanism formed at the upper part of the float cannot take a large buoyancy chamber formed by hollowing out the lower part of the float, and there is a problem that a stable lifting operation cannot be obtained. there were.

JP-A-2-112658

  The present invention is based on solving the above-mentioned problems of the prior art, and in a two-stage float structure, can perform a stable valve closing operation with a large buoyancy, and the upper valve body with respect to the float. An object of the present invention is to provide a fuel shut-off valve that can move up and down in a stable posture.

  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]
Application Example 1 is mounted on the upper part of the fuel tank, and has a casing that forms a valve chamber connected to the outside of the fuel tank and a connection passage that connects the valve chamber and the outside, and is arranged to be movable up and down in the valve chamber. A fuel cutoff valve having a main valve portion for opening and closing the connection passage, and opening and closing the connection passage by raising and lowering the float mechanism according to a fuel level in a fuel tank.
The float mechanism is
An upper wall having an upper wall hole, a side wall that protrudes in a cylindrical shape from the outer peripheral portion of the upper wall and forms a storage chamber together with the upper wall, and is disposed in the storage chamber and exposed from the upper wall hole A float having a valve portion forming member provided with a sub valve portion,
An upper valve body mounted on the upper part of the float so as to be movable up and down, and having a main valve part and a connection hole formed through the main valve part and connected to the connection passage and having a smaller passage area than the connection passage. An upper valve body in which the connection hole is opened and closed by the sub-valve part, and
A spring for biasing the float in the valve closing direction;
With
The float has an engaging portion that faces the upper wall hole and is formed on the upper wall;
The upper valve body has an engaging claw that protrudes from the upper valve body and engages with the engaging portion, thereby restricting movement of the upper valve body in a vertical range within a predetermined range,
The valve part forming member has the sub valve part on the upper part of the valve part forming member, and opens to the bottom and extends to the vicinity of the upper wall to form a spring chamber for storing the spring; A partition wall that divides a space between the outer wall of the storage unit and the upper wall and the inner wall of the side wall, and the partition wall is formed adjacent to the air chamber closed above and the engagement unit Configured to be partitioned into a communication chamber that opens upward through the nail insertion notch,
It is characterized by.

  In the fuel shut-off valve in Application Example 1, fuel enters the valve chamber according to the fuel level in the fuel tank, and opens and closes the connection passage by raising and lowering the float mechanism by giving buoyancy. The float mechanism includes a float and an upper valve body mounted on the upper part of the float so as to be movable up and down. The upper valve body regulates the movement in the ascending / descending direction within a predetermined range by engaging with the engaging portion of the float via the engaging claw. The float is divided into a spring chamber, an air chamber, and a communication chamber by a valve portion forming member. Since the spring chamber and the air chamber are large-volume chambers formed up to the position of the upper wall of the float, a large buoyancy can be generated and a stable lifting operation can be performed. Further, since the communication chamber is opened above the float through the nail insertion notch, the communication chamber can be quickly removed even if fuel enters and there is no hindrance to the lifting operation.

[Application Example 2]
The air chamber and the communication chamber of Application Example 2 can be configured to be alternately arranged in the circumferential direction. With this configuration, the float can be lifted and lowered in a stable posture while suppressing the inclination of the float.

[Application Example 3]
In Application Example 3, the upper valve body includes an upper plate portion and a cylindrical guide member protruding from the lower surface of the upper plate portion, and the valve portion forming member is interposed between the storage portion and the upper portion. Further, it is possible to adopt a configuration having a cylindrical wall forming a guide gap for slidably supporting the guide member. In this configuration, the guide member of the upper valve body is housed in the guide gap of the float, and since the upper valve body does not protrude greatly from the upper part of the float, the height of the fuel cutoff valve 10 itself can be reduced, The upper dead space can be reduced.

[Application Example 4]
The claw insertion notch of the application example 4 can take a configuration in which it is cut out with a width that restricts the movement of the engaging claw in the circumferential direction. With this configuration, the claw insertion notch serves to guide the engaging claw in the up-and-down direction, so that it is not necessary to provide a plurality of notches and holes in the float, and the configuration is simplified.

It is a top view which shows the fuel cutoff valve attached to the upper part of the fuel tank of the motor vehicle concerning one Example of this invention. FIG. 2 is a cross-sectional view taken along line 2-2 in FIG. It is sectional drawing which decomposes | disassembles and shows a fuel cutoff valve. It is a perspective view which shows a float mechanism. It is the perspective view which fractured | ruptured and disassembled the float mechanism partially. FIG. 6 is a sectional view taken along line 6-6 of FIG. 4 and exploded. FIG. 7 is a cross-sectional view taken along line 7-7 in FIG. FIG. 8 is a cross-sectional view taken along line 8-8 in FIG. 7. It is explanatory drawing explaining operation | movement of a fuel cutoff valve. It is explanatory drawing explaining the operation | movement following FIG. It is explanatory drawing explaining the operation | movement following FIG. It is explanatory drawing explaining the operation | movement following FIG.

  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 shut-off valve 10 FIG. 1 is a plan view of a fuel shut-off valve 10 attached to an upper part of a fuel tank of an automobile according to an embodiment of the present invention, and FIG. FIG. In FIG. 2, 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. The fuel shut-off valve 10 regulates the outflow to the canister when the fuel in the fuel tank rises to a predetermined liquid level during refueling and allows the auto stop to function, and thereafter allows only a predetermined amount of additional refueling. The fuel cutoff valve 10 includes a casing 20, a float mechanism 50, and a spring 70 as main components. The casing 20 includes a casing body 30, a bottom plate 35, and a lid body 40. A space surrounded by the casing body 30 and the bottom plate 35 is a valve chamber 20S, and is supported by a spring 70 in the valve chamber 20S. The float mechanism 50 is accommodated.

(2) Configuration of each part of fuel cutoff valve 10 (2) -1 casing 20
FIG. 3 is an exploded sectional view of the fuel cutoff valve. In FIG. 3, the casing 20 includes a casing body 30, a bottom plate 35 attached to the lower part of the casing body 30, and a lid body 40 attached to the upper part of the casing body 30. The casing body 30 includes a ceiling wall part 32 and a side wall part 33 extending in a cylindrical shape downward from the ceiling wall part 32, and is surrounded by the ceiling wall part 32, the side wall part 33, and the bottom plate 35. A cup-shaped valve chamber 20S is formed, and a lower portion thereof is a lower opening 30a. A connecting passage 32a connected to the valve chamber 20S passes through the central portion of the ceiling wall portion 32, and an annular seal portion 32b is formed on the valve passage 20S side of the connecting passage 32a. A first introduction hole 33a that connects the inside of the fuel tank FT and the valve chamber 20S is formed in the lower portion of the side wall 33, and a second introduction hole 33b is formed above the first introduction hole 33b. Further, an engaging claw 33 c is formed at the lower portion of the side wall portion 33. The engaging claw 33 c is for attaching the bottom plate 35.

  The bottom plate 35 is a member that closes the lower opening 30 a of the casing main body 30. By engaging an engaging claw 35 a formed on the outer periphery of the bottom plate 35 with the engaging claw 33 c of the casing main body 30, the lower opening of the casing main body 30 is provided. It is mounted so as to close 30a. A communication hole 35 b is formed through the bottom plate 35. The communication hole 35b is a hole for connecting the inside of the fuel tank and the valve chamber 20S to allow fuel to flow into the valve chamber 20S. A spring support portion 35 c that supports the spring 70 is formed on the upper portion of the bottom plate 35.

  The lid body 40 includes a lid body 41 and a tubular body portion 42 that protrudes from the center of the lid body 41 to one side, and these are integrally formed. The inside of the tube part 42 is a tube passage 42a having a circular cross section. One end of the pipe passage 42a is connected to the valve chamber 20S of the casing body 30 through the connection passage 32a, and the other end is connected to the canister (not shown) side. The lid body 41 includes a flange 41a on the outer periphery thereof. The flange 41a is welded to the inner welding end 41b for welding the inner welding flange 30b of the casing body 30, and the outer side extended to the outer peripheral portion of the inner welding end 41b and welded to the tank upper wall FTa (FIG. 2) of the fuel tank FT. A welding portion 41c.

(2) -2 Float mechanism 50
4 is a perspective view showing the float mechanism 50, FIG. 5 is a partially broken perspective view of the float mechanism 50, FIG. 6 is a sectional view taken along line 6-6 of FIG. FIG. 7 is a cross-sectional view taken along line 7-7 in FIG. The float mechanism 50 is housed in the valve chamber 20 </ b> S (FIG. 2), and includes a float 51 and an upper valve body 60 placed on the top of the float 51.

  5 and 6, the float 51 includes a disk-shaped upper wall 52 having an upper wall hole 52a, and a side wall 53 protruding in a cylindrical shape from the outer peripheral portion of the upper wall 52 downward. A storage chamber 51S (FIG. 5) opened downward is formed. The upper wall 52 has an engaging portion 52b that faces the upper wall hole 52a and is formed by cutting out a part of the opening periphery of the upper wall hole 52a. On the side wall 53, eight guide ribs 53a are formed in a substantially rib shape along the vertical direction and at equal intervals in the circumferential direction, and the valve is arranged so that the outer peripheral end follows the inner wall of the casing body 30 (FIG. 3). The outer diameter is slightly smaller than the inner diameter of the chamber 20S. The guide protrusion 53a guides so as to prevent inclination when the float 51 moves up and down by sliding on the inner wall of the casing body 30.

  As shown in FIG. 6, an integral valve portion forming member 54 is disposed in the storage chamber 51 </ b> S of the float 51. The valve portion forming member 54 divides the storage chamber 51 </ b> S into a plurality of chambers, and includes a storage portion 55, a partition wall 56, and a cylindrical wall 57. The storage portion 55 is connected so as to reduce the diameter of the lower inner cylinder 55a disposed concentrically with the side wall 53, the upper cylinder 55b disposed above the lower inner cylinder 55a, and the lower inner cylinder 55a. A connecting wall 55c to be connected to the upper cylindrical body 55b. The inner space of the storage portion 55 is a spring chamber 55S, which is a lower chamber 55Sa surrounded by the lower inner cylinder 55a and an upper chamber 55Sb surrounded by the upper cylinder 55b. The spring chamber 55S houses the spring 70, and supports the upper end of the spring 70 placed on the spring support portion 35c (FIG. 3) with the connecting wall 55c, thereby urging the float 51 upward. . The sub-valve portion 55d opens and closes a connection hole 65c of the upper valve body 60 described later. The sub valve portion 55d is exposed in the upper wall hole 52a.

  FIG. 8 is a sectional view taken along line 8-8 in FIG. As shown in FIGS. 6, 7, and 8, the partition wall 56 connects the outer wall of the storage portion 55 and the inner wall of the side wall 53, thereby connecting the storage portion 55, the side wall 53, and the cylindrical wall 57. It is a member that divides a space, and is arranged radially at four locations at intervals of 90 ° in the circumferential direction. The space partitioned by the partition wall 56, the upper wall 52, and the side wall 53 is four chambers in which air chambers 56Sa and communication chambers 56Sb are alternately arranged. As shown in FIG. 7, the air chamber 56Sa opens downward and is closed upward. Further, as shown in FIG. 6, the communication chamber 56Sb opens downward and communicates upward by being cut out by the claw insertion cutout 56a.

  As shown in FIGS. 7 and 8, the cylindrical wall 57 is formed in a cylindrical shape downward from the opening peripheral edge of the upper wall hole 52a, and is connected to the connecting wall 55c of the storage portion 55. A guide gap 57Sa is formed between 55b and 55b. As will be described later, the guide gap 57Sa is a gap for guiding the upper valve body 60 in the vertical direction.

  5 and 6, the upper valve body 60 is a valve for improving the restart valve characteristic, and is supported on the upper part of the float 51 so as to be movable up and down, and is attached to the upper valve body 61 and the upper valve body 61. A rubber valve body 65 and a spring 68 interposed between the upper valve body 61 and the float 51 are provided. The upper valve main body 61 includes a disc-shaped upper plate portion 62, a guide member 63 projecting in a cylindrical shape from the outer periphery of the upper plate portion 62, and an engaging claw 64. The guide member 63 includes a cylinder 63a protruding from the lower surface of the upper plate portion 62, and a plurality of guide protrusions 63b formed on the outer periphery of the cylinder 63a. The guide member 63 guides the upper valve body 60 in the up-and-down direction by being inserted into the guide gap 57Sa of the float 51. The engaging claw 64 is cantilevered at two locations downward from the outer peripheral portion of the upper plate portion 62, and is formed to be bent by being arranged at a predetermined gap from the cylinder 63a, and is inserted into the claw insertion notch 56a. In addition, the upper valve body 60 is arranged so as to be able to move up and down within a predetermined distance with respect to the float 51 by engaging the claw engaging portion 52c with the tip portion protruding toward the outer peripheral portion. Yes.

  In FIG. 5, a support hole 62a of the upper plate portion 62 is formed in the central portion of the upper valve main body 61, and the peripheral edge of the opening serves as a valve holding end 62b. A rubber valve element 65 is attached to the valve holding end 62b. The rubber valve body 65 includes a support base portion 65a that is press-fitted and supported by the valve holding end 62b, a main valve portion 65b that is formed on the outer periphery of the support base portion 65a, a connection hole 65c that penetrates the support base portion 65a, and a connection hole 65c. And a lower sheet portion 65d formed at the lower portion of the head. The connection hole 65c is formed in a passage area having a smaller passage area than the connection passage 32a. The rubber valve body 65 has a main valve portion 65b that contacts and separates from the seal portion 32b of the connection passage 32a shown in FIG. 3 and a lower seat portion 65d that contacts and separates from the sub-valve portion 55d of the float 51. The connection passage 32a is opened and closed. As shown in FIG. 6, the spring 68 is disposed on the inner peripheral side of the cylinder 63a of the guide member 63, and is disposed in the guide gap 57Sa, and the upper seat with a spring force that does not open the connection hole 65c. The valve body 60 is urged upward.

(3) Operation at the time of fuel supply of the fuel shut-off valve 10 When fuel is supplied to the fuel tank FT by a fuel gun (not shown) from the opened state of the fuel shut-off valve 10 shown in FIG. As the fuel level in the fuel tank FT rises, the fuel vapor that has been discharged is released mainly to the canister side through the first introduction hole 33a of the side wall 33, and further through the valve chamber 20S, the connection passage 32a, and the pipe passage 42a.

  As the fuel level in the fuel tank FT rises, the liquid fuel flows into the valve chamber 20S through the communication hole 35b and increases the buoyancy of the float mechanism 50. As shown in FIG. 10, when the fuel liquid level in the fuel tank FT reaches the first liquid level FL1, the fuel closes the first introduction hole 33a, thereby increasing the tank internal pressure in the fuel tank FT. In this state, the differential pressure between the tank internal pressure and the pressure in the valve chamber 20S increases, the liquid fuel flows into the valve chamber 20S through the first introduction hole 33a and the communication hole 35b, and the fuel liquid level passes through the valve chamber 20S. To rise. When the fuel level in the valve chamber 20S 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 70 and the downward force due to the weight of the float mechanism 50. The float mechanism 50 rises integrally with the latter, and the main valve portion 65b of the rubber valve body 65 of the upper valve body 60 is seated on the seal portion 32b to close the connection passage 32a. At this time, when fuel accumulates in the inlet pipe and the fuel touches the fuel gun, the auto-stop is activated. As a result, when fuel is supplied to the fuel tank, it is possible to escape the fuel vapor from the fuel tank and to prevent the fuel from flowing out of the fuel tank.

  When the main valve portion 65b of the upper valve body 60 is seated on the seal portion 32b, the main valve portion 65b is held with a force that comes into close contact with the seal portion 32b, and a downward force applied to the upper valve body 60 is reduced. Then, as shown in FIG. 11, when the downward force of the upper valve body 60 is reduced, the spring force of the spring 68 becomes a force that lowers the float 51. By this force, the float 51 moves away from the upper valve body 60. As the float 51 descends, the sub-valve portion 55d opens away from the lower seat portion 65d and opens the connection hole 65c. Due to the communication of the connection hole 65c, the pressure below the upper valve body 60 becomes the same pressure as the vicinity of the connection passage 32a, and the pressure received on both surfaces of the upper valve body 60 is reduced. Then, as shown in FIG. 12, the upper valve body 60 is lowered, the main valve portion 65b is separated from the seal portion 32b, and the connection passage 32a is opened. Thereby, it will be in the state in which additional oil supply is possible. When the fuel level rises due to the additional fuel supply, reaches the second liquid level FL2, and closes the second introduction hole 33b, the tank internal pressure in the fuel tank FT rises again as shown in FIG. The differential pressure between the internal pressure and the pressure in the valve chamber 20S increases, and liquid fuel flows into the valve chamber 20S through the first introduction hole 33a and the communication hole 35b, the float mechanism 50 rises, and the rubber of the upper valve body 60 rises. The main valve portion 65b of the valve body 65 is seated on the seal portion 32b and closes the connection passage 32a. As a result, the auto-stop is activated again, and additional fueling cannot be performed.

(4) Effects of fuel cutoff valve 10 The fuel cutoff valve 10 according to the above embodiment provides the following actions and effects.

(4) -1 As shown in FIG. 7, the spring chamber 55S and the air chamber 56Sa of the float 51 are large-volume chambers formed up to the position of the upper wall 52 of the float 51. The raising / lowering operation can be performed. Therefore, the float is not thickened to obtain a large buoyancy, and there are no problems such as resin sink marks.

(4) -2 As shown in FIG. 5, the guide member 63 of the upper valve body 60 is housed in the guide gap 57Sa of the float 51, and the upper valve body 60 does not protrude greatly from the upper part of the float 51. The height of 10 itself can be made low, and the dead space of the upper part in fuel tank FT can be made small.

(4) -3 Since the guide member 63 of the upper valve body 60 is inserted into the guide gap 57Sa of the float 51, the upper valve body 60 reduces backlash with respect to the float 51 and reliably closes the connection passage 32a. This makes it difficult to leak.

(4) -4 As shown in FIG. 9, the height of the side wall 53 of the float 51 is formed up to the upper portion of the valve chamber 20S and is guided by the side wall 33 through the guide protrusion 53a. Since the float 51 is guided over almost the entire length in the axial direction, the float 51 can obtain a stable lifting operation with little backlash.

(4) -5 As shown in FIG. 6, since the communication chamber 56Sb of the float 51 is opened above the float 51 through the claw insertion notch 56a, it can be quickly removed even if fuel enters, which hinders the lifting operation. There is no. In addition, the claw insertion notch 56a also serves as an engagement with the engagement claw 64 of the upper valve body 60 and a guide action in the up-and-down direction, so there is no need to provide a plurality of notches and holes in the float 51. Configuration is simplified.

(4) -6 When the tank internal pressure around the fuel shut-off valve 10 suddenly increases due to the vehicle swing or the lateral wave of the fuel tank FT, the fuel vapor flows from the lower space of the valve chamber 20S to the large flow velocity from the lower portion of the float 51. You may win. The fuel vapor having such a large flow velocity passes through the claw insertion notch 56a and the guide gap 57Sa from the communication chamber 56Sb and further escapes into the upper space of the valve chamber 20S. The communication chamber 56Sb, the claw insertion notch 56a, and the guide gap 57Sa are open upward in the float 51 where the airflow flows, and the force that raises the float 51 due to the airflow is reduced. Therefore, the float mechanism 50 does not close the connection passage 32a due to a sudden increase in the air flow, and the fuel cutoff valve 10 closes at a stable valve closing liquid level.

(4) -7 At the time of refueling, as shown in FIGS. 10 and 11, the fuel cutoff valve 10 operates the auto-stop at the first liquid level FL1 that closes the first introduction hole 33a, and further opens the second introduction hole 33b. By closing the connection passage 32a with the float mechanism 50 again at the second liquid level FL2 to be closed, the additional oil supply is disabled. At this time, when the main valve portion 65b of the upper valve body 60 is held by a force that is seated on the seal portion 32b and is in close contact with the seal portion 32b, the spring 68 supports the upper valve body 60 upward, and floats. This is the force that lowers 51 downward. Due to this force, the float 51 is moved away from the upper valve body 60 to be opened, and the upper valve body 60 is further lowered. Therefore, the valve is restarted so that additional fuel can be supplied promptly.

(5) Other Embodiments 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 shut-off valve according to the above embodiment was used as a full tank regulating valve that closes the connection passage when the full tank level at the time of refueling, but this is not the only case, and the fuel tank flows out when the vehicle is inclined. You may use for the rollover valve which prevents.

DESCRIPTION OF SYMBOLS 10 ... Fuel cutoff valve 20 ... Casing 20S ... Valve chamber 30 ... Casing main body 30a ... Lower opening 30b ... Inner welding flange 32 ... Ceiling wall part 32a ... Connection passage 32b ... Sealing part 33 ... Side wall part 33a ... 1st introduction hole 33b ... 2nd introduction hole 33c ... Engagement claw 35 ... Bottom plate 35a ... Engagement claw 35b ... Communication hole 35c ... Spring support part 40 ... Cover body 41 ... Cover body 41a ... Flange 41b ... Inner welding end 41c ... Outer welding part 42 ... Pipe body part 42a ... Pipe passage 50 ... Float mechanism 51 ... Float 51S ... Storage chamber 52 ... Upper wall 52a ... Upper wall hole 52b ... Engagement part 52c ... Claw engagement part 53 ... Side wall 53a ... Guide protrusion 54 ... Valve part Forming member 55 ... Housing portion 55S ... Spring chamber 55Sa ... Lower chamber 55Sb ... Upper chamber 55a ... Lower inner cylinder 55b ... Upper cylinder 55c ... Connecting wall 55d ... Sub valve 56 ... Partition wall 56Sa ... Air chamber 56Sb ... Communication chamber 56a ... Claw insertion notch 57 ... Cylindrical wall 57Sa ... Guide gap 60 ... Upper valve body 61 ... Upper valve body 62 ... Upper plate part 62a ... Support hole 62b ... Valve holding end 63 ... Guide member 63a ... Cylinder 63b ... Guide protrusion 64 ... Engagement claw 65 ... Rubber valve element 65a ... Support base part 65b ... Main valve part 65c ... Connection hole 65d ... Lower seat part 68 ... Spring 70 ... Spring FT ... Fuel tank FTa ... Tank upper wall FTb ... Mounting hole

Claims (4)

A casing (20S) attached to the upper part of the fuel tank (FT) and connected to the outside of the fuel tank (FT), and a casing (32a) connecting the valve chamber (20S) and the outside (32a) 20) and a float mechanism (50) having a main valve portion (65b) that is disposed in the valve chamber (20S) so as to be movable up and down and opens and closes the connection passage (32a), and is provided in the fuel tank (FT). In a fuel cutoff valve that opens and closes the connection passage (32a) by raising and lowering the float mechanism (50) according to the fuel level,
The float mechanism (50)
An upper wall (52) having an upper wall hole (52a) and a cylindrical projection projecting downward from the outer peripheral portion of the upper wall (52) together with the upper wall (52) form a storage chamber (51S). A float (51) having a side wall (53) and a valve portion forming member (54) provided with a sub-valve portion (55d) disposed in the storage chamber (51S) and exposed from the upper wall hole (52a);
The upper part of the float (51) is mounted so as to be movable up and down. The main valve part (65b) is formed through the main valve part (65b) and connected to the connection passage (32a). An upper valve body (61) having a connection hole (65c) having a smaller passage area than 32a), and the connection hole (65c) is opened and closed by the sub-valve portion (55d). When,
A spring (70) for biasing the float (51) in the valve closing direction;
With
The float (51) has an engaging portion (52b) that faces the upper wall hole (52a) and is formed in the upper wall (52).
The upper valve body (60) protrudes from the upper valve body (61) and engages with the engaging portion (52b), thereby allowing the upper valve body (60) to move in the vertical direction within a predetermined range. It has an engaging claw (64) that regulates inside,
The valve portion forming member (54) has the sub valve portion (55d) on the upper portion of the valve portion forming member (54), opens downward and extends to the vicinity of the upper wall (52). A partition that divides the space between the storage portion (55) that forms the spring chamber (55S) that stores the spring (70), and the outer wall of the storage portion (55) and the inner walls of the upper wall (52) and the side wall (53). The partition wall (56) has an air chamber (56Sa) closed above and a claw insertion notch (56a) formed adjacent to the engaging portion (52b). Configured to partition into a communication chamber (56Sb) that opens upward through
A fuel shut-off valve characterized by The fuel cutoff valve according to claim 1,
The fuel shutoff valve in which the air chamber (56Sa) and the communication chamber (56Sb) are alternately arranged in the circumferential direction. The fuel cutoff valve according to claim 1 or 2,
The upper valve body (61) has an upper plate portion (62) and a cylindrical guide member (63) protruding from the lower surface of the upper plate portion (62).
The valve part forming member (54) has a cylindrical wall (57) that forms a guide gap (57Sa) into which the guide member (63) is slidably inserted between the valve part forming member (54) and the storage part (55). Shut-off valve. The fuel cutoff valve according to any one of claims 1 to 3,
The claw insertion cutout (56a) is a fuel cutoff valve cut out with a width that restricts movement of the engagement claw (64) in the circumferential direction.

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