JP2006131012A - Valve for fuel tank - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To properly construct a valve for a fuel tank of a synthetic resin material so as to have predetermined weight and volume without enlarging a float valve constituting the valve for the fuel tank. <P>SOLUTION: The float valve 2 stored in a case 1 and moved to a valve closing position due to rising of fuel in a fuel tank T and/or inclination, etc. generated on a vehicle, etc. is furnished with a synthetic resin made cylindrical main floating structure 22 and a synthetic resin made auxiliary floating structure 23 built in this main floating structure 22 and assembled in this main floating structure 22. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an improvement in a valve for a fuel tank.

  It is provided in a gas flow path such as fuel evaporative gas that communicates between the inside and outside of a fuel tank of a vehicle such as an automobile, and closes the flow path when the fuel in the fuel tank rises to a certain level. As a valve having a function, a float having a valve hole located in the flow path on the top wall, and a float that floats by the inflow of fuel into the body and closes the valve hole by a valve portion provided at the top. There is something with. (See Patent Document 1)

  Such a float needs to have a certain weight so that the valve can be quickly lowered from the valve closing position to the valve opening position, but quickly floats to the valve closing position due to the inflow of fuel into the case. It is necessary to have a certain volume. On the other hand, there is a limit to increasing the size of the float from the viewpoint of making the valve compact. If the float is made of a synthetic resin so as to have a constant weight and volume without increasing the size of the entire float, the float becomes thick, so that molding distortion is likely to occur, and the dimensional accuracy is likely to be lowered. Further, since the time for cooling the mold after injecting the synthetic resin into the mold becomes long, it becomes difficult to mold the float in a short cycle.

For this reason, in the valve, a metal weight is assembled to the synthetic resin valve. However, the metal weight incorporated in the float in this way has a smaller volume with respect to the weight. For this reason, the above-mentioned valve tends to make the float heavier, but it is difficult to simply increase the volume while reducing the size of the entire float, making it difficult to increase the buoyancy of the float. Further, since the swelling ratio of the synthetic resin float to the fuel is larger than that of the metal weight, the assembled state of both is likely to be lost over time.
Japanese Utility Model Publication 2-92320

  The main problem to be solved by the present invention is that a float valve (float) having a valve body that lifts up and closes a valve seat constituting a fuel tank valve of this kind is predetermined by a synthetic resin material without increasing the size. It is in the point that it can be appropriately configured so as to have a weight and a volume.

In order to solve the above problems, in the present invention, the fuel tank valve has the following configurations (1) to (3).
(1) A case that is attached to a fuel tank and includes a flow path for a gas such as fuel evaporative gas that communicates between the inside and outside of the fuel tank;
(2) a float valve that is housed in this case and is moved to a valve closing position that closes the flow path due to a rise in fuel in the fuel tank or an inclination generated in a vehicle or the like;
(3) This float valve
A main float structure having a cylindrical shape made of synthetic resin;
And a sub-float structure made of a synthetic resin that is inserted into the main float structure and assembled to the main float structure.

  The float valve constituting the valve comprises a synthetic resin main float component and a synthetic resin sub float component assembled thereto, so that the thickness of both components does not become excessive. Therefore, it is possible to configure a valve including a float valve having a certain weight and volume with high molding accuracy and easy molding in a short cycle. Since the float valve can be reduced in size without hindrance, the entire valve can be made compact.

  In some cases, the outer shape of the sub-float component in contact with the inner surface of the main float component substantially conforms to the inner shape of the main float component.

  In this case, the float valve can be sufficiently reduced in weight while being made as small as possible.

  In some cases, the swelling rate of the synthetic resin material constituting the main float constituent and the synthetic resin material constituting the sub-float constituent is substantially equal to each other.

  In this case, it is possible to prevent the assembled state of the main float structure and the sub float structure from being damaged over time.

  The main float structure and the sub float structure may be made of the same synthetic resin material.

  In this case, it is possible to stably maintain the assembled state of the main float structure and the sub-float structure without considering the swelling ratio of both the structures with respect to the fuel, and to calculate the weight of the float valve. This makes it easy to determine the specifications.

  This insertion end position of the engaging portion provided on the other of the main float structure and the sub float structure, which is elastically deformed as the sub float structure is inserted into the main float structure. A hooked portion to which the hooking portion is hooked may be formed by a bullet.

  In this case, the main float structure and the sub-float structure can be assembled with one touch.

  According to the fuel tank valve of the present invention, the float valve constituting the valve can be appropriately configured so as to have a predetermined weight and volume with the synthetic resin material without increasing the size.

  The best mode for carrying out the present invention will be described below with reference to FIGS.

  Here, FIGS. 1 to 5 show the valves according to the embodiments, respectively. In particular, FIG. 5 shows the use state of the valves by showing the fuel tank T with an imaginary line. A portion of the outer peripheral portion 10a of the flange 10 that overlaps the outer surface portion Tb of the fuel tank T is a welding allowance. 6 and 7 show the main float structure 22 and the sub float structure 23 constituting the float valve 2 separately, and FIGS. 8 to 10 show the main float structure 22 as a diagram. 11 to 15 show the sub float structures 23, respectively. FIG. 16 shows the position of the valve seat 11 of the valve when the vehicle is tilted.

  The valve according to this embodiment is provided in a gas flow path L such as fuel evaporative gas that communicates between the inside and outside of the fuel tank T, and the fuel in the fuel tank T rises to a certain level or occurs in a vehicle or the like. It is a valve having a function of closing the flow path L by a tilt or the like.

  Such a flow path L is typically provided from the fuel tank T to the canister. Such a valve is typically used to close the flow path L when the fuel is raised to a certain level so that the fuel itself is not sent to the canister.

  Typically, such a valve is usually provided in a flow path L connecting the fuel tank T and the canister so that the pressure in the fuel tank T does not abnormally increase or abnormally decrease. It can be used as an opened valve. (So-called cut valve)

  In addition, such a valve is typically a valve having a function of blocking or reducing the air flow to the flow path L of the canister when the fuel level in the fuel tank T reaches a certain level. Can also be used. That is, such a valve increases the internal pressure of the fuel tank T by blocking or reducing the ventilation, and increases the liquid level of the fuel in the fuller tube by increasing the internal pressure. It can be used for the purpose of preventing supercharging by causing the sensor on the side to detect a full tank. (So-called vent valve)

  Such a valve includes a case 1 and a float valve 2.

  The case 1 is attached to the fuel tank T and includes a gas flow path L such as fuel evaporating gas that communicates between the inside and the outside of the fuel tank T.

  In the illustrated example, the case 1 is configured to have a cylindrical shape having an outward flange 10 on the upper portion 1a. A valve seat 11 is formed inside the upper portion 1 a of the case 1, and a connecting pipe 12 is integrally formed outside the upper portion 1 a of the case 1. The pipe inner end of the connection pipe 12 communicates with the valve seat 11. A venting tube P constituting the flow path L to the canister is connected to the outer end side of the connecting pipe 12. A through hole 13 is provided in the side 1b and the bottom 1c of the case 1. In the illustrated example, the bottom 1c of the case 1 is constituted by a cover plate 15 that is assembled to the lower portion of the case main body 14 so as to close the open lower surface of the case main body 14 with the lower surface open. . After the float valve 2 is inserted into the case main body 14 from below the case main body 14, the cover plate 15 is assembled to the case main body 14 so that the valve is configured.

  In the illustrated example, such a valve is inserted below the flange 10 of the case 1 into the mounting hole Ta provided in a penetrating manner in the upper wall portion constituting the fuel tank T, and the fuel tank The outer peripheral portion 10a of the flange 10 is welded and fastened to the outer surface portion Tb of T, so that it can be attached to the fuel tank T.

  In a state in which the float valve 2 is raised and the valve seat 11 is not closed by the valve body 20, the inside and outside of the fuel tank T are connected by the through hole 13 of the case 1, the valve seat 11 and the connection pipe 12. A communicating gas flow path L is formed.

  On the other hand, the float valve 2 is housed in the case 1 and is configured to be moved to a valve closing position that closes the flow path L due to an increase in fuel in the fuel tank T or an inclination generated in a vehicle or the like. Yes.

  In the illustrated example, the float valve 2 is normally positioned by its own weight at a valve opening position where the bottom portion is in contact with the inner surface of the bottom portion 1c of the case 1. When the fuel in the fuel tank T is raised to a certain level, the float valve 2 is lifted to the valve closing position by the fuel flowing into the case 1 from the through hole 13 of the case 1. Further, the float valve 2 is moved to the valve closing position when a certain inclination occurs. In the illustrated example, a recess 21 is formed at the approximate center of the bottom of the float valve 2, and a raised portion 15 a that protrudes upward is formed at the approximate center of the cover plate 15 constituting the case 1. Then, the compression coil spring 3 is inserted between the float valve 2 and the bottom 1c of the case 1 so that the upper end of the spring is inserted into the recess 21 and the raised portion 15a is inserted into the spring from the lower end of the spring. It is intervened. By means of this spring 3, the float valve 2 is always subjected to a constant upward biasing force even in its closed position.

Moreover, the float valve 2 is
A main float structure 22 having a cylindrical shape made of synthetic resin;
The main float structure 22 is composed of a synthetic resin sub-float structure 23 that is inserted into the main float structure 22 and assembled to the main float structure 22.

  In the illustrated example, the main float structure 22 is configured to have a substantially cylindrical shape in which the upper end of the cylinder is generally closed and the lower end of the cylinder is opened. A bulging portion 221 having a short cylindrical shape is formed at a substantially central portion of the outer surface of the upper end of the cylinder of the main float structure 22, and from the substantially central portion of the bulging portion 221 toward the upper side. A valve body 20 having a conical shape that gradually narrows is integrally projected. Further, a cylindrical projecting portion 222 that protrudes downward and opens the bottom end of the cylinder is formed at a substantially central portion of the inner surface of the upper end of the cylinder of the main float structure 22.

  The space in the cylindrical projecting portion 222 continues to the base portion of the raised portion 221, and a round hole-shaped concave portion 223 is formed in the upper portion of the main float structure 22. Further, a tapered recess 224 having a conical hole inner peripheral surface following the outer shape of the valve body 20 is formed inside the valve body 20, and the tapered recess 224 and the round hole-shaped recess 223 are formed. And communicate with each other.

  In addition, four communication holes 225... 225 are formed at substantially equal intervals between adjacent communication holes 225 in the circumferential direction around the raised portion 221 of the main float structure 22. Each of the communication holes 225 is the same between the upper hole 225 a extending long along a virtual circular arc around the raised portion 221, the side surface of the cylindrical protrusion 222, and the inner surface of the main float structure 22. And a lower hole 225b formed at the bottom. Of the four communication holes 225... 225, the lower hole 225b of the two communication holes 225, 225 on both sides in the diameter direction is formed to be narrower than the upper hole 225a. On the hole wall located on the outer surface side of the main float structure 22 in the holes 225 and 225, a step surface 225c facing upward is formed. In the illustrated example, the step surface 225c functions as a hooked portion 225d described later. In the example shown in the drawing, the hole wall located on the inner side of the main float structure 22 in the two communication holes 225 and 225 has a vertical direction at a position approximately in the middle of the left and right direction of the communication hole 225. A groove 225e is formed extending in the direction.

  On the other hand, in this embodiment, the sub float structure 23 is fitted into the main float structure 22 from the open bottom end of the main float structure 22, and the main float structure 22 is inserted. It is comprised so that it may be integrated.

  In the illustrated example, the sub-float structure 23 has a truncated cone portion 231 that fits into the tapered recess 224 of the main float structure 22 at a top portion thereof, and a lower portion of the truncated cone portion 231. Thus, a substantially equal interval is provided between the columnar portion 232 that fits in the round hole-shaped concave portion 223 of the main float structure 22 substantially densely and the projecting piece 233 that is adjacent to the cylindrical portion 232 in the circumferential direction. Four protrusions 233... 233 that are provided and protrude upwardly and fit into the communication hole 225 of the main float constituting body 22 from the lower side substantially densely.

  The outer peripheral surface between the upper part and the lower part of the sub float structure 23 is configured to have a cylindrical outer peripheral surface that fits in the main float structure 22 almost densely.

  In addition, the concave portion 21 is formed at substantially the center of the bottom portion of the sub-float structure 23, and the sub-float structure body 23 is hollowed to reach the cylindrical portion 232 following the concave portion 21. A hole 234 is formed.

  Of the four projecting pieces 233... 233 of the sub float structure 23, the two projecting pieces 233, 233 on both sides in the diametrical direction have a pair of longitudinal grooves 233a, 233a and the pair of longitudinal grooves 233a, respectively. An elastic piece 233c divided by a transverse groove 233b extending between the lower ends of the grooves 233a is formed, and a hooking protrusion 233d having a hooking surface 233e facing downward is formed on the lower outer surface of the elastic piece 233c. Is formed. In the illustrated example, the engaging protrusion 233d functions as an engaging portion 233f described later.

  The float valve 2 needs to have a certain weight so that the valve valve can be quickly lowered from the valve closing position to the valve opening position. However, the float valve 2 is brought to the valve closing position by inflow of fuel into the case 1. It is necessary to have a certain volume so that it can rise quickly. On the other hand, there is a limit to increasing the size of the float valve 2 from the viewpoint of making the valve compact. When the float valve 2 is made of synthetic resin so as to have a constant weight and volume without increasing the size, the float valve 2 is thickened, so that molding distortion is likely to occur and dimensional accuracy is likely to be lowered. Further, since the time for cooling the mold after injecting the synthetic resin into the mold becomes long, it is difficult to mold the float valve 2 in a short cycle.

  In this embodiment, the float valve 2 constituting the valve includes a main float structure 22 made of synthetic resin and a sub float structure 23 made of synthetic resin to be assembled thereto. Therefore, the float valve 2 having a constant weight and volume is obtained without excessively increasing the thickness of both the structural members 22 and 23, and thus with high molding accuracy and easy molding in a short cycle. The provided valve can be configured. Since the float valve 2 can be reduced in size without hindrance, the entire valve can be made compact.

  In the illustrated example, the float valve 2 is configured by assembling one sub-float structure 23 to the main float structure 22, but two or more sub-float structures 23, 23. The float valve 2 can be configured by being assembled.

  Further, in this embodiment, the outline shape of the portion of the sub float structure 23 that is in contact with the inner surface of the main float structure 22 is substantially the same as the outline shape of the main float structure 22. Yes.

  In the illustrated example, the outer contour shape extending from the upper portion to the lower portion of the sub-float component body 23 substantially follows the inner contour shape extending from the upper portion to the lower portion of the main float component body 22. The sub float structure 23 fitted into the main float structure 22 from the lower end fills the inner space of the main float structure 22 almost densely.

  As a result, in this embodiment, the float valve 2 can be made sufficiently small while being made as small as possible.

  Further, if the swelling ratio of the synthetic resin material constituting the main float constituting body 22 and the synthetic resin material constituting the sub float constituting body 23 with respect to the fuel is made substantially equal, the main float constituting body 22 and the sub float constituting the main float constituting body 22 are substantially equal. It can prevent that the assembly | attachment state with the structure 23 will be impaired over time.

  Further, if the main float structure 22 and the sub float structure 23 are made of the same synthetic resin material, the main float structure 22 and the sub float structure 22 and the sub float structure 23 are not considered without considering the swelling ratio of both the structures 22 and 23 with respect to the fuel. The assembly state with the float structure 23 can be stably maintained, and specification of the float valve 2 such as calculation of the weight of the float valve 2 can be easily performed.

  Further, the engagement provided on either one of the main float structure 22 and the sub float structure 23, which is elastically deformed with the insertion of the sub float structure 23 into the main float structure 22 If the hooked portion 225d to which the hook portion 233f is hooked is formed by the bullet at the insertion end position of the portion 233f, the main float structure body 22 and the sub float structure body 23 can be assembled with one touch. it can.

  In the illustrated example, the sub-float structure is inserted into the communication hole 225 of the main float structure 22 from the lower hole 225 b of the communication hole 225 as the sub-float structure 23 is inserted into the main float structure 22. The protruding piece 233 of the body 23 is inserted, and the engaging protrusion 233d of the elastic piece 233c of the protruding piece 233 provided with the elastic piece 233c is connected to the communication hole 225 provided with the step surface 225c. After the elastic piece 233c is once bent by being pressed against the hole wall, the engagement of the elastic piece 233c at the insertion position where the engagement protrusion 233d enters above the stepped surface 225c causes the engagement. The surface 233e is engaged with the step surface 225c.

  In the illustrated example, the groove 225e formed in the hole wall of the communication hole 225 of the main float structure 22 functions as a bending space for the elastic piece 233c of the projecting piece 233 of the sub float structure 23. It is supposed to be.

  It is preferable that the pitch between the outer surface of the float valve 2 and the inner surface of the case 1 is gradually narrowed toward the lower side. If it does in this way, the fuel which flows in in the case 1 through the through-hole 13 of the bottom 1c of the case 1 will not easily enter between the outer surface of the upper part of the float valve 2 and the inner surface of the upper part of the case 1, and the valve seat 11 Thus, it is possible to more reliably prevent the fuel from leaking out of the fuel tank T, typically to the canister side.

  Further, in the illustrated example, when the valve seat 11 is inclined about 39 degrees due to the inclination generated in the vehicle or the like or the turning acceleration of the vehicle, the side portion of the case 1 It is positioned above the horizontal line y passing through the upper edge of the through hole 13 of 1b. (FIG. 16) Thus, in the example shown in the figure, at the moment when such an inclination occurs, the valve seat 11 has a case 1 in the valve seat 11 earlier or at the same time as the float valve 2 moves to the valve closing position. The fuel that has entered the case 1 from the through hole 13 of the side portion 1b does not reach.

Front view of valve Side view Plan view Bottom view AA line sectional view in FIG. 3 (use state) Separate perspective view of float valve 2 Separate perspective view of float valve 2 Plan view of main float structure 22 Bottom view BB sectional view in FIG. Side view of the sub float structure 23 Front view Plan view Bottom view CC sectional view in FIG. Valve cross section

Explanation of symbols

T Fuel tank L Flow path 1 Case 2 Float valve 22 Main float component 23 Sub float component

Claims (5)

A case attached to the fuel tank and provided with a gas flow path such as fuel evaporative gas communicating between the inside and outside of the fuel tank;
A float valve that is housed in this case and is moved to a valve closing position that closes the flow path due to a rise in fuel in the fuel tank or an inclination generated in a vehicle, etc.
This float valve
A main float structure having a cylindrical shape made of synthetic resin;
A fuel tank valve comprising: a synthetic resin sub-float component that is inserted into the main float component and assembled to the main float component.   2. The fuel tank for a fuel tank according to claim 1, wherein an outer shape of a portion of the sub-float structure that is in contact with an inner surface of the main float structure substantially follows the inner shape of the main float structure. valve.   3. The fuel according to claim 1, wherein the swelling rate of the synthetic resin material constituting the main float constituent and the synthetic resin material constituting the sub-float constituent is substantially equal to each other. Tank valve.   3. The fuel tank valve according to claim 1, wherein the main float structure and the sub float structure are made of the same synthetic resin material.   At one of the main float structure and the sub float structure, at the insertion end position of the engaging portion provided on the other of the main float structure and the other, which is elastically deformed as the sub float structure is inserted into the main float structure. The fuel tank valve according to any one of claims 1 to 4, wherein a hooked portion to which the hooking portion is hooked is formed by the bullet.

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