JP2005335502A - Vehicular fuel tank - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicular fuel tank in which the rigidity thereof is enhanced and the noise level is reduced while suppressing an increase of the number of components and the weight to a minimum. <P>SOLUTION: The vehicular fuel tank T has a cylindrical member 11 of a substantially circular section which is blow-molded of synthetic resin, and the cylindrical member 11 folded in a winding manner consists of six straight parts 12a-12f extending parallel to each other, and five bent parts 13a-13e to connect adjacent ends of the six straight parts 12a-12f to each other in a U-shape. Joining parts of the cylindrical member 11 are functioned as reinforcing ribs to obtain the high rigidity capable of withstanding the change in the internal pressure associated with the temperature change, and to suppress generation of fluctuation of the fuel level and the noise by functioning the joining parts as a baffle plate. In addition, no special reinforcing member or baffle plate is required, an increase of the number of components and the weight can be suppressed to a minimum. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a vehicle fuel tank that stores fuel to be supplied to a vehicle engine.

A conventional fuel tank for a vehicle is manufactured by separately manufacturing an upper half whose lower surface is opened with a metal or a synthetic resin and a lower half whose upper surface is opened, and a flange and a lower half which are provided on the lower surface of the upper half. It was comprised in the container shape sealed by combining with the flange provided in the upper surface open | release part (for example, refer the following patent document 1).
JP 11-11167 A

  By the way, since the fuel tank for vehicles mounted on the lower surface of the vehicle body generally has a shape that is wide in the front-rear direction and left-right direction and flat in the vertical direction, if the internal pressure of the fuel tank increases or decreases due to temperature changes, There is a problem that the upper and lower walls having a large area are deformed in the vertical direction. In order to prevent deformation of the fuel tank due to temperature changes, it is necessary to press and fix the fuel tank to the lower surface of the floor with a strong mounting band, or to provide a special reinforcing member or special reinforcing rib on the fuel tank, This has been a factor in increasing the number of parts and weight.

  In addition, if the fuel level in the fuel tank fluctuates greatly or wiggles due to acceleration or swaying as the vehicle travels, it may interfere with fuel suction or cause noise when the fuel collides with the inner surface of the fuel tank. There is a problem to do. In order to solve this problem, if a baffle plate is provided inside the fuel tank or a rubber is sandwiched between the fuel tank and the lower surface of the floor, the number of negative items and weight will also increase.

  The present invention has been made in view of the above-described circumstances, and an object thereof is to enable improvement in fuel tank rigidity and noise reduction while minimizing an increase in the number of parts and weight.

  In order to achieve the above object, according to the first aspect of the present invention, the outer surfaces of the cylindrical members that are bent a predetermined number of times are connected to each other, and fuel is stored in the cylindrical member. A fuel tank for a vehicle is proposed.

  According to the second aspect of the present invention, in addition to the configuration of the first aspect, a vehicle fuel tank is proposed in which the portions of the cylindrical members in contact with each other constitute a common partition wall. . According to the invention described in claim 3, in addition to the configuration of claim 1 or 2, a vehicle fuel tank is proposed in which a cylindrical member is blow-molded with a synthetic resin.

  According to the configuration of the first aspect, since the fuel tank is configured by connecting the outer surfaces of the cylindrical members that are bent a predetermined number of times to each other, the joining portion of the cylindrical member functions as a reinforcing rib to change the temperature. In addition to obtaining high rigidity that can withstand the accompanying changes in internal pressure, the joint can function as a baffle plate to suppress fluctuations in the fuel level and noise, and a special reinforcing member and baffle plate. Therefore, the increase in the number of parts and the weight can be minimized.

  According to the structure of Claim 2, since the part which a cylindrical member mutually contacts comprises a common partition, the weight of a partition can be suppressed to the minimum and a fuel tank can be reduced in weight.

  According to the third aspect of the present invention, by adopting the synthetic resin blow molding, it is possible to easily manufacture a fuel tank having a structure in which the outer surfaces in contact with each other of the cylindrical members bent a predetermined number of times are combined.

  Hereinafter, embodiments of the present invention will be described based on examples of the present invention shown in the accompanying drawings.

  1 to 5 show an embodiment of the present invention. FIG. 1 is a perspective view of a vehicle fuel tank, FIG. 2 is a sectional view taken along line 2-2 of FIG. 1, and FIG. 3 is 3-3 of FIG. FIG. 4 is a diagram illustrating a manufacturing process of a vehicle fuel tank, and FIG. 5 is an operation explanatory diagram corresponding to FIG.

  As shown in FIGS. 1 to 3, the fuel tank T for a vehicle includes a cylindrical member 11 having a generally circular cross section that is blow-molded with a synthetic resin. Six straight portions 12a to 12f extending in parallel to each other and five bent portions 13a to 13e that connect adjacent end portions of the six straight portions 12a to 12f in a U-shape. The tubular member 11 is bent on the same plane, and the fuel tank T has a rectangular shape in plan view and is formed flat in the vertical direction.

  The inside of the fuel tank T is partitioned between the six straight portions 12a to 12f by five partition walls 14a to 14e, and each partition wall 14a to 14e is not double but is single. That is, the adjacent two linear portions 12a to 12f are partitioned by one common partition wall 14a to 14e.

  The fuel pump unit 18 is attached to the lower surface of the mounting flange 16 that detachably covers the opening 15 formed in the upper wall of one of the five straight portions 12a to 12f (the straight portion 12c in the embodiment) via a stay 17. A feed pipe 19 that is supported and extends from the fuel pump unit 18 passes through the mounting flange 16 and is connected to an engine (not shown), and a return pipe 20 from the engine passes through the mounting flange 16 and a fuel tank. It extends into T. A liquid level sensor 22 having a float 21 is provided on the lower surface of the mounting flange 16.

  Next, a method for manufacturing the fuel tank T will be described with reference to FIG.

  First, as shown in FIG. 4A, a parison 24 obtained by extruding a thermoplastic resin into a tube shape through a die orifice 23 is set in a zigzag cavity 25 a formed in a first mold 25. Subsequently, as shown in FIG. 4B, when the second mold 26 is clamped with respect to the first mold 25, the air nozzle 27 provided in the second mold 26 pierces the parison 24. Subsequently, as shown in FIG. 4C, when air is blown from the air nozzle 27 into the parison 24, the expanded parison 24 is pressed against the cavity 25a of the first mold 25 and the cavity 26a of the second mold 26. As a result, the tubular member 11 is blow-molded. At this time, the outer surfaces of the adjacent straight portions 12a to 12f are brought into contact with each other to be integrated to form the common partition walls 14a to 14e, so that the weight can be reduced by sharing the partition walls 14a to 14e. .

  Since the tubular member 11 of the fuel tank T blow-molded in this way has its upper wall and lower wall connected to each other by the partition walls 14a to 14e, when the internal pressure increases due to temperature rise, the partition walls 14a to 14e. Supports the tensile load, and when the internal pressure decreases due to the temperature drop, the partition walls 14a to 14e support the compressive load, thereby preventing the fuel tank T from being deformed in the vertical direction without requiring a special reinforcing member or reinforcing rib. can do.

  In addition, if the fuel level in the fuel tank T greatly fluctuates due to acceleration or swaying as the vehicle travels, the fuel suction port of the fuel pump unit 18 may be exposed outside the fuel level and hinder fuel suction. However, as shown in FIG. 5, the partition walls 14 a to 14 e exhibit the function of the baffle plate, whereby the fluctuation of the fuel liquid level can be minimized and the above problem can be solved.

  Furthermore, noise is generated when the fuel rippling due to acceleration or swaying as the vehicle travels collides with the inner surface of the fuel tank T vigorously. However, the partition walls 14a to 14e exert the function of the baffle plate to cause the fuel undulation. Noise can be reduced to a minimum without providing a special baffle plate.

  The embodiments of the present invention have been described above, but various design changes can be made without departing from the scope of the present invention.

  For example, in the embodiment, the cylindrical member 11 is bent in a zigzag shape, but the bending method is arbitrary, and the zigzag shape may be folded in a spiral shape or a combination of a zigzag folding shape and a spiral bend shape.

  Moreover, the manufacturing method of the cylindrical member 11 is not limited to blow molding, You may couple | bond the upper half body and lower half body which were divided into 2 up and down.

  Further, instead of forming the tubular member 11 into a previously bent shape, the tubular member formed in a linear shape may be bent later to join the contact portions.

Perspective view of vehicle fuel tank 2-2 sectional view of FIG. 3-3 sectional view of FIG. The figure explaining the manufacturing process of the fuel tank for vehicles Action explanatory diagram corresponding to FIG.

Explanation of symbols

11 Tubular members 12a to 12f Straight portions 13a to 13e Bent portions 14a to 14e Partition wall 24 Parison T Fuel tank

Claims (3)

  A fuel tank for vehicles, wherein outer surfaces of cylindrical members that are bent a predetermined number of times are connected to each other and fuel is stored inside the cylindrical member.   The fuel tank for vehicles according to claim 1, wherein the portions of the cylindrical members that are in contact with each other constitute a common partition wall. The vehicle fuel tank according to claim 1 or 2, wherein the cylindrical member is blow-molded with a synthetic resin.

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