JPH09240294A - Fuel supply pipe for automobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To have necessary flexibility given to a fuel supply tube, enable the tube to be integrally formed up to its base part so as to aim at simplification of production process, by using a stainless steel tube of a particular plate thickness so as to carry out processing by a corrugated processing method. SOLUTION: A stainless steel tube 1 of 0.4-0.6mm plate thickness is used as a fuel supply tube 10 so that it can be formed integratedly up to its base part 13 and the bellows part 10a is formed by corrugated processing method so as to compensate for flexibility drop of the bellow part 10a owing to the increase of thickness. In this way, flexibility necessary for the fuel supply tube 10 can be secured. And the other end 1B of the stainless steel tube 1 is subjected to tube expansion work and screw work to be integrally formed as the base part 13. Because of its large plate thickness, even though it is formed in the base part 13 by means of tube expansion work and screw work, strength necessary for its use can be secured. In this way, integral formation up to the base part 13 becomes available, production processes can be remarkably simplified so as to reduce the production cost.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel oil supply pipe for an automobile, and more particularly, to a novel improvement for integrally forming a bellows portion and a base portion using a stainless steel pipe having a wall thickness of 0.4 to 0.6 mm. Regarding

[0002]

2. Description of the Related Art Generally, a conventional fuel oil supply pipe is made of a steel pipe such as STKM having an inner surface subjected to surface treatment such as galvanization so as not to be corroded by intermittent passage of gasoline or light oil, as shown in FIG. The mouthpiece portion 13 of the steel pipe 1 equipped with the blizzer tube on the oil filler port 1a side is formed by pipe expanding / screwing, and has a structure in which a cap is screwed in via the vehicle body 6 for plugging. On the other hand, this steel pipe 1 is fastened to a fuel tank 7 mounted on a chassis 9 via a bracket 8 by a flexible tube 3 made of rubber or the like capable of absorbing vibrations due to different vibration modes of the vehicle body 6 and the chassis 9 and absorbing mounting errors. The metal fittings 4 are connected so that fuel does not leak. However, in this method, rust prevention may be insufficient depending on the use environment, and an unnecessarily large filter must be installed at the outlet of the fuel tank 7, and the rubber of the flexible tube 3 deteriorates. There is a drawback in that the sealing by the tightening metal fitting 4 becomes poor and the fuel, particularly gasoline that is easily vaporized, easily leaks. In order to prevent this leakage, there is a problem that a very expensive fluororubber must be used.

In order to prevent such a drawback, a fuel oil supply pipe 10 in which a bellows portion 10a is integrally formed using the stainless steel pipe 1 disclosed in Japanese Utility Model Laid-Open No. 56-212221 shown in FIG. 3 has been proposed. . That is, the fuel filler pipe 10 of FIG. 3 is formed with the blister tube 2 similar to that of FIG.
And a packing 11 are provided, and the mouthpiece portion 13 is formed separately from the stainless steel pipe 1 and attached later.

[0004]

According to the conventional construction of Japanese Utility Model Laid-Open No. 56-212121 shown in FIG. 3, the stainless steel pipe 1 has a plate thickness of 0.2 to 0.2 as shown in FIG. Three
A thin stainless steel pipe having a thickness of mm is used in which the bellows portion is partially processed by the hydraulic bulge method, and the bellows portion is intended to replace the rubber of the flexible tube 3 in FIG. However, the fuel oil supply pipe 10 needs the mouthpiece portion 13 for repeatedly screwing and removing the cap at the time of oil supply, but the fuel oil supply pipe 10 having the configuration of FIG. 3 is designed with the highest priority on flexibility. Therefore, the wall thickness of the stainless steel pipe 1 is 0.2 to 0.3.
Since it is thin and has no strength, the base portion 13 cannot be integrally formed, and the separately manufactured base portion 13 needs to be joined to the stainless steel pipe 1 by brazing or the like. Therefore, there is a risk that gasoline may leak in the brazing part, and the manufacturing process is complicated, resulting in a high cost.

The present invention has been made to solve the above problems, and in particular, a stainless steel pipe having a wall thickness of 0.4 to 0.6 mm is integrally formed up to the bellows portion and the die portion. An object is to provide a fuel filler pipe for an automobile.

[0006]

A fuel oil supply pipe for an automobile according to the present invention is a fuel oil supply pipe for an automobile, which is connected to a fuel tank and integrally has a bellows portion, and which is made of a stainless steel pipe, and has a wall thickness of 0.4 to 0.2. This is a structure in which the mouthpiece is integrally formed with the 6 mm stainless steel pipe.

More specifically, the bellows portion is processed by corrugation.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of a fuel oil supply pipe for an automobile according to the present invention will be described in detail below with reference to the drawings. The same or equivalent parts as those in the conventional example will be described using the same reference numerals. In FIG. 1, reference numeral 1 is a stainless steel pipe having a wall thickness of 0.4 to 0.6 mm and a blister tube 2, and a pair of bellows portions 10a is provided at a substantially central portion of the stainless steel pipe 1. It is formed integrally. One end 1A of the stainless steel pipe 1 is connected to the fuel tank 7, and the other end 1B is formed with a mouthpiece portion 13 having a diameter larger than the diameter of the stainless steel pipe 1 and integrally formed. It is fixed to the vehicle body 6.

As the fuel oil supply pipe 10, a stainless steel pipe 1 having a plate thickness of 0.4 to 0.6 mm is used so that the mouth portion 13 can be integrally formed. Bellows portion 10 is used to compensate for the decrease in flexibility.
a is not a hydraulic bulge method, but is, for example, Japanese Patent Publication No. Sho 49-430.
Molding is performed by a well-known corrugating method represented by the method disclosed in Japanese Patent No. 69. In the case of a fuel oil supply pipe, if the outer diameter of the base pipe is the same, the corrugated machining method has a smaller trough diameter than the hydraulic bulge method.
Even in the case of the stainless steel pipe 1 having a thickness of 0.6 mm, the flexibility required for this application can be obtained. Therefore, the other end 1B of the stainless steel pipe 1 is expanded and screwed to be integrally formed as the mouthpiece portion 13. However, since the wall thickness is large as described above, the mouthpiece portion 1 is formed by the pipe expansion processing and the screwing.
Even if it is molded into No. 3, it can have the strength required for the intended use.

Therefore, the fuel oil supply pipe 10 has a plate thickness of 0.4-0.
Since the 6 mm stainless steel pipe 1 is used and the bellows molding process by corrugation process is applied, the trough diameter of the corrugated part is smaller than that of the hydraulic bulge method, and it is 0.4 to 0.0.
Even in the case of the 6 mm thick stainless steel pipe 1, the flexibility required for this application can be obtained. By such corrugation, it is possible to sufficiently absorb the vibration and the mounting error due to the different vibration modes. It should be noted that the die having the required strength can also be obtained by the integral molding, and it can be manufactured at a low cost by a simple manufacturing process.

[0011]

Since the vehicle fuel oil supply pipe according to the present invention is constructed as described above, the following effects can be obtained. That is, since a stainless steel pipe having a plate thickness of 0.4 to 0.6 mm is used and processed by the corrugating method, not only has the flexibility necessary for the fuel oil supply pipe,
It is also possible to integrally mold up to the mouthpiece part, so that the manufacturing process is greatly simplified and the manufacturing cost can be reduced.

[Brief description of drawings]

FIG. 1 is a schematic view of a fuel oil supply pipe for an automobile of the present invention.

FIG. 2 is a schematic view of a conventional vehicle fuel oil supply pipe.

FIG. 3 is a schematic view of a conventional stainless bellows type fuel oil supply pipe.

[Explanation of symbols]

 1 Stainless Steel Pipe 2 Blizzer Tube 6 Car Body 7 Fuel Tank 10 Fuel Refueling Pipe 10a Bellows 13 Clasp

Claims (2)

[Claims] 1. A bellows portion (10) connected to a fuel tank (7).
In a fuel oil supply pipe for an automobile having a) integrally formed of a stainless steel pipe (1), a base portion (13) is integrally formed on the stainless steel pipe (1) having a wall thickness of 0.4 to 0.6 mm. Characteristic fuel supply pipe for automobiles. 2. The fuel oil supply pipe for an automobile according to claim 1, wherein the bellows portion (10a) is processed by corrugation.