JP2001270337A - Small component fixing part for synthetic resin-made fuel tank - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a structure of a small component fixing part for a synthetic resin-made fuel tank capable of restraining the deterioration of accuracy of the small components fitting part and the reduction of strength against external forces, caused by the deterioration with the lapse of time, without inducing the deterioration of manufacturing property and the excessive increase in weight. SOLUTION: An engaging part mounted integrally on the opening of the blow-molded synthetic resin fuel tank (1) is installed as the structure for fixing a small component through the medium of a seal member between the engaging part and a fastening member paired with the engaging part in the cylindrical part (12) formed by burying the wall of the tank (1) inwardly. The fastening member is provided with an annular part (14) fitted into the inner periphery surface of the cylindrical part (12). Consequently, only the thickness of a part supporting the small component, where the seal member is installed, can be increased without increasing the thickness of the tank (1) because the part contacts the inner surface of a metallic mold early.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for fixing small parts to a synthetic resin fuel tank, and more particularly to fixing a small part such as a pump module to an opening provided in a synthetic resin fuel tank. It is related to the structure of.

[0002]

2. Description of the Related Art A fuel tank formed by blow molding a synthetic resin material is known (see Japanese Patent Publication No. 7-17160). In order to assemble a small component such as a pump module into such a synthetic resin fuel tank, a protrusion having an external thread formed on the outer peripheral surface is provided on the outer wall of the tank, and a union nut is screwed onto the external thread to form the small component. Is generally adopted.

[0003] On the other hand, in blow molding, the thickness of the portion that first comes into contact with the inner surface of the mold when air is blown tends to be largest. The protruding portion of the tank outer wall that comes into contact last means that it has the thinnest wall. That is, according to the conventional structure in which the male screw is formed on the protruding portion, it is troublesome to secure the strength as the mounting portion for the small component.

[0004] Increasing the thickness of this portion to ensure strength results in a relative increase in the thickness of other portions, which leads to an increase in weight. In addition, it is conceivable to insert-mold the tank body after forming the attachment part of the small part as a separate member, but this complicates the manufacturing process and causes a problem of the strength of the joint part between different materials. Therefore, it is not always optimal for enhancing reliability.

[0005]

That is, according to the prior art, it is difficult to satisfy the trade-off demands of reducing the weight of the tank body and securing the strength of the small component mounting portion.
As a result, the design flexibility of the synthetic resin fuel tank was hindered.

[0006] The present invention has been devised to solve such problems of the prior art, and its main objects are as follows.
To provide a structure of a small-part fixing part for a synthetic resin fuel tank that can suppress the deterioration of the precision of the small-part mounting part due to aging and a decrease in strength against external force without causing a decrease in manufacturability and an excessive increase in weight. Is to do.

[0007]

In order to achieve the above object, according to the present invention, an engaging portion provided integrally with an opening of a blow-molded synthetic resin fuel tank is provided. As a structure for fixing a small component via a seal member, between a pair of fastening members, the engaging portion,
An annular portion (14) is provided on a cylindrical portion (12) formed by immersing a wall of the tank (1) inward, and the fastening member is fitted on an inner peripheral surface of the cylindrical portion. It is intended to provide a structure of a small part fixing portion for a synthetic resin fuel tank, which is provided with the fuel tank.

[0008] According to this structure, the portion where the small member is supported and the seal member is installed comes into contact with the inner surface of the mold at an early stage. Therefore, only the thickness of the portion is reduced without increasing the thickness of the entire tank. Can be bigger.

In particular, a radially inward flange (7a) is provided at the inner end in the axial direction of the cylindrical portion, and the inner peripheral edge of the flange is formed as an opening (7). By providing the outward flange (6a) and sandwiching the seal member (8) between these two flanges, only the thickness of the seal portion can be easily and efficiently increased.

In addition to these, a female screw (11) is formed on the inner peripheral surface of the cylindrical portion, and a male screw (1) screwed to the female screw is formed.
If 3) is characterized in that it is formed in the annular portion, the small parts can be fixed to the tank by screw connection.

[0011]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 shows a fuel tank T to which the present invention is applied.
The whole is shown. The fuel tank T has a main tank 1 which functions as a fuel storage tank and a main tank 1 which shuts off the liquid level fluctuation due to the movement of the vehicle so that the suction port of the fuel pump 2 always sinks below the liquid level. And a sub-tank 3 provided in the sub-tank. And in the main tank 1,
A connection port 4 with an oil supply pipe which is opened at an appropriate position on the vehicle body is provided.

The sub-tank 3 comprises a cylindrical container 5 having a bottom with a fuel inlet provided at an appropriate position, and a container 5 having a bottom.
And a lid plate 6 fitted in a liquid-tight manner into the opening of the main tank 1 and inserted into the main tank 1 through an opening 7 provided in the upper wall of the main tank 1. As shown in an enlarged view in FIG. 2, the radially outward flange 6 a formed on the cover plate 6 is liquid-tight via the seal member 8 with respect to the radially inward flange 7 a formed on the opening 7 of the main tank 1. Joined to.

The fuel pump 2 is housed inside the container 5. The cover plate 6 is integrally provided with a discharge passage 9 connected to a discharge port of the fuel pump 2 and a return passage 10 for returning excess fuel from the engine.

The main tank 1 is formed seamlessly by blow molding, and a cylindrical portion 12 having an internal thread 11 provided on an inner peripheral surface thereof is formed integrally with a part of an upper wall thereof being immersed inward. Is formed. By cutting off the bottom wall of the cylindrical portion 12 by secondary processing, the radially inward flange 7a for supporting the radially outward flange 6a of the cover plate 6 and the sub tank 3 are inserted into the main tank 1. Opening 7 is formed.

Between a radially inward flange 7a whose inner peripheral edge forms an opening 7 and a radially outward flange 6a of the cover plate 6,
After sandwiching a sealing member 8 such as an O-ring or a gasket, an annular holding ring 14 having an external thread 13 formed on the outer peripheral surface thereof is screwed into the female screw 11 on the inner peripheral surface of the cylindrical portion, thereby forming the outward flange 6a and the inwardly facing ring. The sealing member 8 is appropriately compressed between the flange 7a and the desired sealing property is obtained.

A stopper means comprising an axial end face 15 (see FIG. 3) abutting on the upper surface of the inward flange 7a of the cylindrical portion 12, or an outward flange 16 (see FIG. 4) abutting on the outer surface of the upper wall of the main tank 1. Is provided on the holding ring 14 so that the sub tank 3
By controlling the interference of the press ring 14 when fixing the sealing member 8, the pressing force applied to the seal member 8 can be made constant.

Thus, the initial stage of blow molding,
That is, since the material comes into contact with the mold at a stage where the thickness is relatively large, it is possible to relatively easily achieve the increase in the thickness of the small-part engaging portion. In addition, by forming the female screw in this thick part, the strength of the screw part can be easily secured, so that the occurrence of looseness in the screw part due to thinning due to deterioration with time such as creep phenomenon is also eliminated.

The holding ring 14 is connected not only by screw means but also by a claw 18 which is caught by an engaging projection 17 protruding from the inner peripheral surface of the cylindrical portion 12 as shown in FIG. The pressing ring 14 may be connected to the tubular portion 12 by utilizing the elastic deformation of the synthetic resin material itself by pushing the ring.

[0020]

As described above, according to the present invention, during blow molding, a portion for supporting a small part and installing a seal member comes into contact with the inner surface of the mold at an early stage. Only the thickness can be increased without increasing the thickness of the entire tank. Therefore, in combination with the fact that there is no need to perform insert molding of a separate member, a large effect can be achieved in increasing the strength and sealing performance of the small component fixing portion without increasing the weight of the entire tank or lowering the manufacturability. Can be played. In particular, if the seal member is sandwiched between the radially inward flange provided on the cylindrical portion and the radially outward flange provided on the small component, only the thickness of the seal portion is easily and efficiently increased. Therefore, higher sealing performance can be obtained without increasing the weight. Furthermore, if the male screw of the annular portion is screwed to the female screw of the inner peripheral surface of the cylindrical portion, the small parts can be fixed to the tank by screw connection, so that the manufacturability can be further improved.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a synthetic resin fuel tank to which the present invention is applied.

FIG. 2 is an enlarged sectional view of a main part of the present invention.

FIG. 3 is an enlarged sectional view of a main part showing another embodiment.

FIG. 4 is an enlarged sectional view of a main part showing still another embodiment.

FIG. 5 is an enlarged sectional view of a main part showing still another embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Main tank 2 Fuel pump 3 Sub tank 4 Connection port 5 Container body 6 Cover plate 6a Outward flange 7 Opening 7a Inward flange 8 Seal member 9 Discharge passage 10 Return passage 11 Female screw 12 Cylindrical part 13 Male screw 14 Pressing ring 15 Axial end face 16 Outward flange 17 Engagement projection 18 Claw

Claims (3)

[Claims] 1. A seal member is interposed between an engagement portion provided integrally with an outer peripheral portion of an opening of a blow-molded synthetic resin fuel tank and a fastening member forming a pair with the engagement portion. Wherein the engaging portion is provided on a cylindrical portion formed by inwardly immersing a wall of the tank, and the fastening member is provided inside the cylindrical portion. A structure of a small component fixing portion for a synthetic resin fuel tank, comprising an annular portion fitted to a peripheral surface. 2. A radially inward flange is provided at an inner end in the axial direction of the cylindrical portion, and an inner peripheral edge of the flange is used as the opening, and a radially outward portion is provided at a portion of the small component located outside the opening. The structure of a small-part fixing portion for a synthetic resin fuel tank according to claim 1, wherein a flange is provided, and the seal member is sandwiched between the two flanges. 3. The synthetic resin according to claim 1, wherein a female screw is formed on an inner peripheral surface of the cylindrical portion, and a male screw to be screwed with the female screw is formed on the annular portion. The structure of the small part fixing part to the fuel tank.