JP2006182217A - Fuel shut-off valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To quickly correct a valve mechanism in which a float is inclined, raised and abutted on a seat part and to enhance sealing property of the valve mechanism to the seat part in a fuel shut-off valve. <P>SOLUTION: The fuel shut-off valve 10 has a casing 20; a float body 41 lifted by increasing/decreasing buoyancy by a fuel liquid level in a valve chamber 30S; and the valve mechanism 44 placed on an upper part of the float 41 body and opening/closing a connection passage 32b and a spring 48 is interposed between the float body 41 and the valve mechanism 44. The valve mechanism 44 is constituted by a valve element 45 and a seal member 49 and a projection part 47 is formed on a lower part of the valve element 45. It is set such that it abutted on a recession part 42a of an upper wall of the float body 41 immediately after the float body 41 is raised and the seal member 49 is seated on a seat part 32c. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

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

  Conventionally, patent document 1 etc. are known as this kind of a fuel cutoff valve. As shown in FIG. 6, the fuel cutoff valve 100 is mounted on the upper part of the fuel tank, and a casing 101 provided with a connection passage connected to the outside (canister) in the upper part thereof, and in the valve chamber S of the casing 101. A float 102 that raises and lowers buoyancy according to the fuel level and a valve mechanism 103 placed on the float 102 are provided. The fuel flows into the valve chamber S due to the rise of the fuel level in the fuel tank, the float 102 increases the buoyancy, and the valve mechanism 103 rises integrally with the float 102, thereby closing the connection passage and fuel. Is prevented from leaking outside.

  The valve mechanism 103 is supported on the upper portion by a spring 104 interposed between the upper portion of the float 102 and the valve mechanism 103. With such a configuration, when the float 102 is tilted and seated on the seat portion 105 due to the inclination of the vehicle or the like, the valve mechanism 103 that contacts the seat portion 105 corrects the tilt and completely closes the seat portion 105 so that the canister Prevents fuel spills.

However, according to this configuration, when the spring overload of the spring 104 is set low, the valve mechanism 103 comes into contact with the seat portion 105 and corrects the tilt quickly. However, since the biasing force of the spring is weak, the valve mechanism The adhesiveness to the seal part 105 of 103 will become weak, and a sealing performance will become low. Further, when the spring overload is set high, the adhesion of the valve mechanism 103 to the seat portion 105 is increased, but the phenomenon of a contradiction occurs that the valve mechanism 103 that has hit one side is difficult to correct the inclination.
Japanese Patent Laid-Open No. 10-238429

  The present invention is based on solving the above-mentioned problems of the prior art, and the float is tilted and rises, the valve mechanism that hits the seat part corrects quickly, and the sealing performance of the valve mechanism to the seat part is improved. An object of the present invention is to provide a fuel cutoff valve.

The present invention made to solve the above problems
In a fuel cutoff 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 casing body that forms a valve chamber that communicates the inside of the fuel tank and the connection passage;
A float main body that is housed in the valve chamber and moves up and down by increasing or decreasing buoyancy depending on the fuel level in the valve chamber, and is placed on the upper portion of the float main body via a spring member so as to be movable in the axial direction of the float main body. A float mechanism having a valve mechanism for opening and closing the connection passage by raising and lowering the float body;
With
The valve mechanism has a protrusion on the upper wall portion of the float body that is separated from and connected to the shaft center at a single point, and the protrusion is separated from the upper wall portion by a predetermined amount when the connection passage is open. The spring member is set so that it is compressed by a predetermined amount and abuts against the upper wall after the float body is raised and the connection passage is closed;
It is characterized by.

  In the fuel cutoff valve according to the present invention, when the fuel in the fuel tank reaches a predetermined liquid level, the float main body is raised by buoyancy due to the fuel flowing into the valve chamber, and the valve mechanism is also raised integrally with the float main body. The valve mechanism closes the connection passage, thereby shutting off the fuel tank from the outside and preventing the fuel from flowing out from the fuel tank.

  The engaged portion of the valve mechanism is supported by an engaging portion provided on the upper wall portion of the float body, and a spring is interposed between the valve mechanism and the float body. In addition, a seat portion on which the valve mechanism is seated is present on the valve chamber side opening end peripheral portion of the connection passage. When the liquid level rises while tilting with respect to the float mechanism due to a sudden turn of the vehicle or the like, the float mechanism rises while tilting with respect to the seat portion of the connection passage, and the valve mechanism of the float mechanism hits the seat portion. Here, since the excessive weight of the spring is set lightly, the inclination of the valve mechanism is quickly corrected with respect to the seat portion, and the valve mechanism completely blocks the connection passage.

  At this time, the projection formed on the valve mechanism is set so as to be supported and contacted with the upper wall portion of the float body shortly after the valve mechanism blocks the connection passage. Therefore, since the upward force is received not only from the urging force of the spring but also from the float body, the sealing performance of the valve mechanism that shuts off the seat portion is enhanced. With this configuration, even if the float mechanism tilts and rises and hits the seat portion, the valve mechanism can quickly correct and improve the sealing performance of the valve mechanism to the seat portion.

  As another aspect, the valve mechanism includes a valve body having an engaged portion that engages with an engaging portion provided on an upper wall portion of the float body, and flexibility for opening and closing the connection passage. A projecting seat portion is formed at the valve chamber side opening end peripheral portion of the connection passage, and the valve body and the seal are disposed around a seating surface of the seal member seated on the seat portion. It is possible to adopt a configuration in which a valve body recess is formed in the valve body so as to provide a gap between the members.

  At least a gap is provided between the valve body and the seal member so that when the seal member of the valve mechanism is seated on the protruding seat portion provided at the peripheral edge of the opening of the connection passage, the seal member around the seat is bent. As a result, the sealing performance is improved and the inclination can be easily corrected.

  As another aspect, the valve body may be formed of a resin material, the seal member may be formed of a rubber material, and the protrusion may be integrally formed with the valve body.

  Furthermore, as another aspect, the protrusion may be formed in a conical shape. With this configuration, even when only the float main body is tilted due to vehicle vibration, etc., the projection follows the upper wall of the float main body while supporting it at a single point, thus maintaining high sealing performance to the seat of the valve mechanism it can.

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.
A. First Example (1) Schematic Configuration of Fuel Shutoff Valve 10 FIG. 1 is a cross-sectional view showing a fuel cutoff valve 10 attached to an upper portion of a fuel tank (not shown) of an automobile according to an embodiment of the present invention. The fuel shut-off valve 10 regulates the outflow of fuel to the outside (canister) when the fuel in the fuel tank rises to a predetermined liquid level.

  The fuel cutoff valve 10 includes a casing body 30, a bottom plate 35, a float mechanism 40, a spring 20, and a lid 50 as main components. The casing body 30, the bottom plate 35, and the float body 41 (float mechanism 40) are made of a synthetic resin polyacetal having excellent fuel permeation resistance and fuel oil resistance. On the other hand, the lid 50 is formed by mixing polyacetal having excellent fuel permeation resistance as a base material and polyethylene as a dispersion material. That is, the dispersion material is formed of the same polyethylene as the fuel tank FT and is a material for welding.

  The casing body 30 includes a ceiling wall portion 32 and a side wall portion 33 extending in a cylindrical shape downward from the ceiling wall portion 32, and is cup-shaped surrounded by the ceiling wall portion 32 and the side wall portion 33. A valve chamber 30S is formed, and a lower portion thereof is a lower opening 30a. An upper protrusion 32 a is formed at the center of the ceiling wall portion 32 of the casing body 30. A connection passage 32b passes through the upper protrusion 32a, and a seat portion 32c is formed at the opening end of the connection passage 32b on the valve chamber 30S side. An annular step 32d for supporting the O-ring 36 is formed on the outer peripheral side wall of the upper protrusion 32a. An engagement hole 33 a is formed in the lower portion of the side wall portion 33. This engagement hole 33a is for attaching the bottom plate 35 as will be described later.

  The bottom plate 35 is a member that closes the lower opening 30a of the casing body 30, and an engaging portion 35a formed on the outer periphery of the bottom plate 35 engages with the engaging hole 33a. Mounted to close. The bottom plate 35 is formed with a communication hole 35b that communicates the valve chamber 30S and the inside of the fuel tank FT. Therefore, the inside of the fuel tank FT communicates with the valve chamber 30S through the communication hole 35b. A projecting spring support portion 35 c is formed at the center upper portion of the bottom plate 35. The spring support portion 35 c supports the spring 20 between the inner lower surface of the float body 41.

  The float mechanism 40 accommodated in the valve chamber 30S includes a float main body 41 and a valve mechanism 44, and a spring 48 is interposed as a spring member therebetween. The float body 41 is configured in a container shape having an upper wall portion 42 and a cylindrical side wall portion 43 formed downward from the outer periphery of the upper wall portion 42, and the inner space generates buoyancy. Buoyancy chamber 40S. A guide protrusion 41a is formed on the outer peripheral portion of the float body 41 and is guided by the inner wall on the casing body 30 side. An upper wall recess 42a is formed at the center of the upper wall 42, and four engaging portions 42b are formed around the upper wall recess 42a so as to face the central axis of the float body 41. The valve mechanism 44 includes a valve body 45 made of a resin material and a seal member 49 made of a rubber material seated on the seat portion 32c at the upper part thereof. The valve main body 45 is formed with an engaged portion 46, and the engaged portion 46 is formed with an engaging hole 46 a that engages with the engaging portion 42 b of the float main body 42. In addition, a valve body recess 45a is formed in the upper part of the valve body 45, and when the seal member 49 is seated on the seat portion 32c, the seal member 49 bends to ensure high sealing performance, and high processing accuracy at the time of molding is also achieved. The configuration is unnecessary. Further, a conical protrusion 47 is formed at the lower center of the valve body 45. As will be described later, the protrusion 47 is a member that abuts against the upper portion of the float body 41 by bending the spring 48.

  On the other hand, the lid 50 includes a lid main body 51, a tube part 52 protruding in an L shape from the center of the lid main body 51 to the upper part, a flange part 53 formed on the outer periphery of the lid main body 51, and a lower part of the lid main body 51. And a fitting portion 54 projecting from each other, and these are integrally formed. A lid fitting portion 51 a for fitting the upper protruding portion 32 a of the casing body 30 is formed at the lower center of the lid body 51. Further, a lid side passage 52a is formed in the tubular body 52, and one end of the lid side passage 52a is connected to the connection passage 32b of the casing body 30, and the other end is connected to the canister side. Further, an annular welded portion 53 a that is welded to a tank upper wall FTa (not shown) of the fuel tank FT is formed at the lower end portion of the flange portion 53. Further, the fitting portion 54 is provided in a cylindrical shape so as to fit the upper portion of the casing body 30, and a slit 54 a and an engagement hole 54 b that are open at the lower end side are formed in a part of the fitting portion 54. .

Next, an operation of mounting the fuel cutoff valve 10 on the tank upper wall (not shown) of the fuel tank will be described. In FIG. 1, the float mechanism 40 and the spring 20 are housed in the valve chamber 30 </ b> S of the casing body 30, and the lower end of the spring 20 is aligned with the spring support portion 35 c of the bottom plate 35 and the engaging portion of the bottom plate 35. The bottom plate 35 is attached to the casing body 30 by engaging 35 a with the engagement hole 33 a of the side wall portion 33. Further, the O-ring 36 is inserted into the upper protruding portion 32a and held on the annular step portion 32d. In this state, the fitting portion 54 is fitted to the upper portion of the casing body 30, and the upper protruding portion 32a is covered with the lid. It fits into the fitting part 51a. At this time, the engagement protrusion 37 engages with the engagement hole 54b, and the lid 50 and the casing body 30 are integrated. Moreover, since the position of the front end of the fitting portion 54 is regulated by the inner peripheral surface of the outer peripheral portion 35d, it is possible to prevent the lid 50 and the casing body 30 from falling off due to fuel swelling.
(3) Operation of the fuel cutoff valve 10 Next, the operation of the fuel cutoff valve 10 will be described. When the vehicle tilts and the fuel level rises to reach a predetermined level, the fuel flows into the valve chamber 30S through the communication hole 35b of the bottom plate 35. Thereby, as shown in FIG. 2, buoyancy arises in the float main body 41 and it raises, and the valve mechanism 44 sits on the seat part 32c. After that, as shown in FIG. 3, the spring 48 is compressed by a predetermined amount, and the protrusion 47 abuts on the float upper wall recess 42 a, so that the spring 48 receives the sheet portion 32 c received from the float body 41 in addition to the urging force. The sealing performance of the seat portion 32c is enhanced by force to close the connection passage 32b, so that the fuel does not flow out to the canister side. Therefore, the fuel cutoff valve 10 can escape the fuel vapor from the fuel tank FT and prevent the fuel from flowing out of the fuel tank FT.

  On the other hand, when the vehicle turns sharply and rises in liquid level while tilting with respect to the float mechanism 40, the float body 41 rises while tilting with respect to the seat portion 32c, and the valve mechanism 44 of FIG. The seal member 49 comes into contact with the sheet portion 32c. At this time, since the spring overload of the spring 48 is set low, the inclination of the valve mechanism 44 is corrected with respect to the seat portion 32c, and the seal member 49 is completely seated on the seat portion 32c as shown in FIG. To do. Further, as shown in FIG. 4C, the spring 48 is bent by a predetermined amount, so that the projection 47 of the valve mechanism 44 is supported at one point on the upper wall recess 42a of the float body 41 and comes into contact therewith. Therefore, in addition to the biasing force of the spring, an upward force is also received from the float main body 41, and the adhesion of the seal member 49 to the seat portion 32c is increased and the sealing performance is improved.

  Further, since the protrusion 47 is formed in a conical shape, the float mechanism 40 is not inclined with respect to the seat portion 32c as shown in FIG. 3, and when the seal member 49 is seated on the seat portion 32c, When only the float main body 41 is tilted due to vibration or the like, the projection 47 has a conical shape and follows the upper concave portion 42a while supporting it at one point. Therefore, the adhesion of the valve portion 49 to the seat portion 32c is not impaired, and a high seal is achieved. Sex is maintained.

  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.

  For example, in the above embodiment, the protrusion 47 is formed on the valve body 45. However, the present invention is not limited to this, and the valve mechanism 44B is made of a rubber having a resin valve body 45B and a protrusion 47B as shown in FIG. You may be comprised with the sealing member 49B.

It is sectional drawing which shows the fuel cutoff valve attached to the upper part of the fuel tank of the motor vehicle concerning 1st Example of this invention. It is the figure which the fuel cutoff valve interrupted | blocked the connection channel at the time of the normal fuel liquid level rise. FIG. 3 is an explanatory diagram for explaining an operation following FIG. 2. It is explanatory drawing explaining operation | movement of the fuel cutoff valve which interrupts | blocks a connection channel | path at the time of the rocking | fluctuation raise of a fuel liquid level. It is sectional drawing which shows the fuel cutoff valve concerning 2nd Example of this invention. It is sectional drawing which shows the conventional fuel cutoff valve.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Fuel cutoff valve 20 ... Spring 30 ... Casing main body 30a ... Lower opening 30S ... Valve chamber 32 ... Ceiling wall part 32a ... Upper protrusion part 32b ... Connection passage 32c ... Sheet part 32d ... annular step part 33 ... side wall part 33a ... engagement hole 35 ... seat plate 35a ... engagement part 35b ... communication hole 36 ... O Ring 40 ... Float mechanism 41 ... Float main body 41a ... Guide protrusion 42 ... Upper wall part 42a ... Upper wall concave part 42b ... Valve main body 43 ... Side wall part 44 ... Valve mechanism 44B ... Valve mechanism 45 ... Valve body 45B ... Valve body 45a ... Valve body recess 46 ... Engagement part 46a ... Engagement hole 47 ... Projection part 47B・ ・ Protrusions 48 ・ ・ ・ Spring 49 ・ ・ ・ Seal member 49B ・··· Sealing member 50 ··· Lid 51 ··· Lid body 52 ··· Tube portion 53 ··· Flange portion 53a · · · annular weld portion 54 · · · fitting portion 54a · · · slit 54b · · · ..Engagement holes

Claims (4)

In a fuel shut-off valve that is mounted on the upper part of the fuel tank and opens and closes a connection passage (32b) that connects the inside and outside of the fuel tank so as to cut off communication between the fuel tank and the outside.
A casing body (30) forming a valve chamber (30S) communicating the inside of the fuel tank and the connection passage (32b);
A float body (41) that is housed in the valve chamber (30S) and moves up and down with increasing or decreasing buoyancy depending on the fuel level in the valve chamber (30S), and a spring member (48) on the top of the float body (41). Float mechanism (40) having a valve mechanism (44) that is mounted so as to be movable in the axial direction of the float body (41) and opens and closes the connection passage (32b) when the float body (41) moves up and down. )When,
With
The valve mechanism (44) has a protrusion (47) that is separated from and connected to the axial center of the upper wall (42) of the float body,
The protrusion (47) is separated from the upper wall (42) by a predetermined amount when the connection passage (32b) is open,
After the float main body (41) is lifted and the connection passage (32b) is closed, the spring member (48) is set to be compressed by a predetermined amount and brought into contact with the upper wall (42). ,
A fuel shut-off valve characterized by The fuel cutoff valve according to claim 1,
The valve mechanism (44) includes a valve body (45) having an engaged portion (46) that engages with an engaging portion (42b) provided on an upper wall portion (42) of the float body, and the connection It comprises a flexible sealing member (49) that opens and closes the passage (32d), and a protruding seat portion (32c) is formed at the peripheral edge of the connection passage (32d) on the valve chamber (30S) side opening end. The valve main body (45) is provided around the seating surface of the seal member (49) seated on the seat portion (32c) so that a gap is provided between the valve main body (45) and the seal member (49). 45) A fuel cutoff valve characterized in that a valve body recess (45a) is formed in 45). The fuel cutoff valve according to claim 2,
The valve body (45) is made of a resin material, the seal member (49) is made of a rubber material, and the protrusion (47) is formed integrally with the valve body (44). Shut-off valve. The fuel cutoff valve according to any one of claims 1 to 3,
The fuel cutoff valve, wherein the protrusion (47) has a conical shape.