JP2005082013A - Mounting structure of component in resin fuel tank - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mounting structure of a component of a resin fuel tank for improving sealing property without interposing a seal member such as an O-ring and satisfying strength, rigidity and high barrier property. <P>SOLUTION: This mounting structure of a back flow check valve 2 is provided with a joint part 3 having a bonding part to a resin tank main body 1 formed by a thermal weldable material and bonded to the tank main body 1 by thermal welding and a valve main body part 4 formed by a non-welding member and inserted into the tank main body 1 to be bonded to the joint part 3. At least either one of the joint part 3 or the valve main body part 4 is provided with a moving regulating means for regulating a shaft direction moving of the valve main body part 4 in relation to the joint part 3. The joint part 3 and the valve main body part 4 are formed as integral molding. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a resin fuel tank mounted on an automobile or the like.

  In recent years, fuel tanks mounted on automobiles are mainly made of resin type by blow molding from the viewpoint of rust prevention and weight reduction. Normally, the fuel tank has a vent valve for leading the fuel evaporative gas in the space above the liquid surface outside the tank and keeping the tank internal pressure constant, a backflow prevention valve connected to the filler tube, or a fuel pump, etc. Various components are attached, and in the case of a resin fuel tank, from the viewpoint of simplifying the manufacturing process, it is desirable that the component and the tank main body are joined by thermal welding.

  FIG. 4 is a partial cross-sectional view showing a mounting structure of component parts in a conventional resin fuel tank. Reference numeral 24 denotes a tank body of a resin fuel tank, and the component 31 is attached to a through hole formed in the housing wall of the tank body 24. In the figure, the component 31 is shown as a backflow prevention valve, and is a cylindrical shape having a joint portion 32 having a flange 36 joined to the outer surface of the tank body 24 and a valve mechanism 40 inserted into the tank body 24 at the tip. The valve main body part 33 is provided. The joint portion 32 is formed with a primary molding portion 37 made of a material that can be welded to the tank main body 24 and a hole 39 through which a molten resin material can flow, and two colors on the inner periphery of the flange 36. And a secondary molding portion 38 made of an HC (hydrocarbon) barrier material layer formed by a molding method. The HC barrier material is generally a non-welded member.

  On the other hand, the housing of the valve body 33 is formed of a non-welding member such as POM (polyacetal resin). The valve body 33 is engaged with the joint 32, and an O-ring 52 is interposed in a part of the engagement surface. The O-ring 52 is for ensuring airtightness between the inside and outside of the tank. Usually, a fuel tank is provided with a blister port (not shown) as a vent for refueling, and the air in the fuel tank is basically vented only through this blister port. . Accordingly, if there is a gap between the joint portion 32 and the valve main body portion 33, air may leak from that portion, and the O-ring 52 is provided to prevent this air leakage.

Now, since the outside of the flange 36 is formed as the primary molding portion 37, the component 31 is coupled to the tank body 24 by heat welding on the outer wall side of the tank body 24. Since the inner part of the flange 36 facing the inside of the tank body 24 is formed by a secondary molding portion 38 made of an HC barrier material layer, permeation of HC (hydrocarbon) to the outside of the tank is caused by the secondary molding portion 38. It is suppressed. The above structure is also disclosed in Patent Document 1, for example.
JP 2003-2074 A (FIG. 1, [0022])

  In the conventional component 31, since the joint portion between the joint portion 32 and the valve main body portion 33 is formed by a non-welding member, they cannot be joined by heat welding. After the main body portion 33 is engaged with the joint portion 32, the gap between the two is sealed by the O-ring 52. However, the structure in which the O-ring 52 is interposed causes an increase in the number of parts and a reduction in assembly efficiency.

  The present invention has been made to solve such problems, and is a resin fuel that improves sealing performance and satisfies strength, rigidity, and high barrier properties without interposing a sealing member such as an O-ring. A structure for mounting the components of the tank is provided.

  In order to solve the above problems, the present invention provides a joint portion with a resin tank body formed of a heat-weldable material, a joint portion coupled with the tank body by thermal welding, and supported by the joint portion, An internal cylinder member built in the tank body, wherein the internal cylinder member is attached to at least one of the joint part and the internal cylinder member. A movement restricting means for restricting the movement of the member in the axial direction is provided, and the joint portion and the inner cylinder member are formed by integral molding.

  According to the structure, the sealing performance can be improved and the strength / rigidity and the high barrier performance can be satisfied without separately interposing a sealing member such as an O-ring.

  According to the present invention, since the component parts are manufactured integrally, the assembly work of the joint portion and the inner cylinder member is unnecessary, and the assembly efficiency of the entire unit of the resin fuel tank is improved. Become. In addition, since the joint portion and the inner cylinder member are firmly joined together, the backlash is reduced, and the assembling accuracy with respect to the tank body is improved. Further, since there is no need to separately provide a seal member such as an O-ring as in the prior art, the number of parts can be reduced, and the assembly of an O-ring or the like is not necessary. The assembly efficiency of the entire unit is improved.

  In the following embodiment, a case will be described in which a resin fuel tank is a fuel tank mounted on an automobile, and a component to be attached is a backflow prevention valve connected to a filler tube for refueling.

<First Embodiment>
FIG. 1 is a cross-sectional view schematically showing a structure for mounting a component (backflow prevention valve 2) according to the present embodiment, and FIG. 2 is an enlarged view showing the backflow prevention valve 2 shown in FIG. FIG. 2A is a cross-sectional explanatory view, and FIG. 2B is a front view seen from the inside of the tank. In these drawings, a fuel tank T is provided with a resin tank body 1 for storing fuel, and a backflow prevention valve 2 for preventing backflow of fuel is attached to a side surface of the tank body 1. The backflow prevention valve 2 includes a joint portion 3 attached to the outer peripheral edge of a through-hole 1c formed on the side surface of the tank body 1 and a valve mechanism 5 at the tip, and is supported by the joint portion 3 so that the tank body 1 And a cylindrical inner cylinder member (valve body part 4) inserted (built-in) inside. The tank body 1 is made of, for example, a material capable of thermally welding the HC barrier material layer 1b made of EVOH (ethylene vinyl alcohol copolymer) having excellent HC (hydrocarbon) impermeability, such as PE (polyethylene). It has a cross-sectional shape sandwiched between heat-weldable layers 1a.

  The joint portion 3 is a flange portion 3a attached to the outer peripheral edge portion of the through-hole 1c by heat welding, and a tube connecting tube portion 3c formed from the flange portion 3a toward the outside of the tank and fitted with a filler tube H. It has a shape with The portions of the flange portion 3a and the tube connecting tube portion 3c that face the outside of the tank body 1 are formed of a heat-weldable material such as PE (polyethylene).

  The portion formed continuously across the surface of the flange portion 3a facing the inside of the tank body 1 and the inner peripheral surface of the tube connecting tube portion 3c is HC (hydrocarbon) such as EVOH (ethylene vinyl alcohol copolymer). It is formed as the HC barrier material layer 3b which is excellent in opacity. The HC barrier material layer 3b and the flange portion 3a formed of PE (polyethylene) or the like and the portion of the tube connecting pipe portion 3c facing the outside of the tank body 1 are formed by two-color molding, The integral joint part 3 is comprised.

  A casing of the valve main body 4 is formed on a cylindrical cylinder body 4a that is gradually reduced in diameter toward the side to be connected to the joint part 3, and on the distal end side of the cylinder body 4a, and incorporates the valve mechanism 5. In this embodiment, it is formed by a non-welding member such as POM (polyacetal resin). The valve mechanism 5 is configured as a backflow prevention mechanism 6 that prevents a backflow of fuel from the tank body 1 side to the filler tube H side, and includes a sliding portion 6a and a spring 6b. It is fixed to the valve built-in body part 4b by the fixing part 7. The valve fixing portion 7 is provided with an insertion port 7a, and fuel is supplied into the tank body 1 through the insertion port 7a.

  In the present invention, when the joint portion 3 and the valve main body portion 4 are coupled, at least one of the joint portion 3 or the valve main body portion 4 is a movement that restricts the axial movement of the valve main body portion 4 with respect to the joint portion 3. The main feature is that the restricting means is provided and the joint portion 3 and the valve body portion 4 are formed as an integral molding. As the integral molding, molding by a mold, particularly insert molding is economical, and in this embodiment, backflow prevention is achieved by inserting POM (polyacetal resin) into the joint portion 3 formed by the two-color molding described above. The entire housing of the valve 2 is integrally formed.

  As the movement restricting means, an annular protrusion 3e is provided on the inner peripheral surface in the vicinity of the end of the tube connecting pipe portion 3c so as to bite into the outer periphery of the cylinder body 4a, and the HC facing the inner side of the tank body 4 is provided. The projecting portion 4c formed in an annular shape on the outer peripheral surface of the cylindrical body portion 4a is abutted against the end surface 3d of the barrier material layer 3b. As a result, the valve body 4 is formed integrally with each other by insert molding as described above after the axial movement of the valve body 4 is reliably restricted with respect to the joint 3.

  According to the present invention, since the backflow prevention valve 2 is manufactured integrally, the assembly work of the joint portion 3 and the valve main body portion 4 is not required, and the assembly efficiency of the entire resin fuel tank unit is improved. Will be improved. Moreover, since the joint part 3 and the valve main body part 4 are firmly joined together, the backlash is reduced and the assembling accuracy with respect to the tank main body 1 is improved.

  Furthermore, the joint part 3 and the valve body part 4 are formed as an integral molding with a mold, and especially by insert molding, the sealing performance between the two is ensured, and the O-ring is conventional. This eliminates the need for a separate sealing member. Therefore, the number of parts can be reduced, and the assembly of an O-ring or the like is not necessary. From this point, the assembly efficiency of the entire resin fuel tank unit is improved. In addition, since a large seal area can be secured as compared with the case of the O-ring, the sealing performance is also improved as compared with the conventional case.

<Second Embodiment>
Next, a second embodiment will be described. FIG. 3 is an enlarged cross-sectional view for explaining the second embodiment. In the present embodiment, the same elements as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted. This embodiment is different from the first embodiment in the specific shape related to the movement restricting means. In the first embodiment, on the tube connecting tube portion 3c side, an annular protrusion 3e is provided so as to bite into the outer periphery of the cylindrical body portion 4a, and the end surface 3d of the HC barrier material layer 3b facing the inner side of the tank body 1 is provided. In this embodiment, the annular protrusion 4c is abutted against the outer peripheral surface of the cylinder body 4a. However, in this embodiment, a hook-shaped claw part 4d is provided at the end of the cylinder body 4a of the valve body 4. The claws 4d are formed and externally fitted to the end 3f of the HC barrier material layer 3b facing the inside of the tank body 1.

  Also with this structure, the axial movement of the valve body 4 with respect to the joint 3 is reliably restricted, and the joint 3 and the valve body 4 are integrally formed by insert molding. Also according to the present embodiment, sealing performance is ensured between the joint portion 3 and the valve main body portion 4, and there is no need to separately provide a sealing member such as an O-ring as in the conventional case. Therefore, the number of parts can be reduced, and the assembly of an O-ring or the like is not necessary. From this point, the assembly efficiency of the entire resin fuel tank unit is improved.

  The preferred embodiments have been described above. However, the present invention is not limited to the above-described embodiments, and appropriate modifications can be made without departing from the scope of the present invention. For example, in the present embodiment, the description is applied to a fuel tank of an automobile. However, the present invention is not limited to this, and can be applied to a fuel tank mounted on a ship or the like, for example.

It is sectional drawing which shows the outline of the attachment structure of the component parts of the resin fuel tank of this invention. It is an enlarged view which shows the backflow prevention valve shown in FIG. 1, (a) is sectional explanatory drawing, (b) is the front view seen from the inner side of the tank. It is explanatory drawing which concerns on 2nd Embodiment, (a) is sectional explanatory drawing, (b) is the front view seen from the inner side of the tank. It is a partial cross section explanatory drawing which shows the attachment structure of the conventional backflow prevention valve.

Explanation of symbols

H Filler tube T Fuel tank 1 Tank body 2 Backflow prevention valve (component)
3 Joint 4 Valve body (inner cylinder member)

Claims (1)

A joint part with a resin tank body is formed of a heat-weldable material, a joint part joined by thermal welding with the tank body, an inner cylinder member supported by the joint part and incorporated in the tank body, A mounting structure for component parts in a resin fuel tank comprising:
At least one of the joint part or the inner cylinder member is provided with a movement restricting means for restricting the axial movement of the inner cylinder member relative to the joint part, and the joint part and the inner cylinder member are integrated. A structure for mounting component parts in a resin fuel tank, which is formed by molding.

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