JP2007216935A - Fuel feed pipe - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel feed pipe capable of suppressing or preventing electrolytic corrosion of a feed pipe body, attachment members and a vehicle body while suppressing cost increase by as partial measures as possible. <P>SOLUTION: This fuel feed pipe 1 is constituted by mounting a mounting bracket 12 with respect to the vehicle body to the feed pipe body 11 made of stainless steel. The mounting bracket 12 mounted to the stainless steel feed pipe body 11 is normally made of steel, and a portion of the mounting bracket 12 at least contacting the feed pipe body 11 is galvanized. In addition to the mounting bracket 12, a mounting flange 13 positioning and fixing an oil filler and a support bracket 15 of a breather pipe 14 etc. are also normally made of steel and are galvanized. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a fuel supply pipe constructed by attaching an accessory member to a stainless steel supply pipe main body.

  In recent years, with the extension of the life of vehicles, stainless steel members having excellent anticorrosion properties have been frequently used, and fuel supply pipes are no exception. Certainly, stainless steel exhibits excellent corrosion resistance due to the action of the passive film on the surface. However, since the attachment member is attached to the oil supply pipe body, it is necessary to perform welding, brazing or plastic working on the oil supply pipe body, so the stainless steel of the oil supply pipe body changes the crystal structure and is partially passivated. There is a possibility that the film may be damaged, and the defective part of the passive film may cause electrolytic corrosion. In addition, if the electrolyte accumulates and concentrates in the gaps between the attached parts that are assembled in a complicated manner, the passive film of the stainless steel oil supply pipe body may disappear and electrolytic corrosion may occur from the gaps. There is.

  For example, Japanese Patent Application Laid-Open No. H10-133707 discloses that the fuel supply pipe main body is subjected to cationic electrodeposition coating on the entire fuel supply pipe (fuel inlet) against partial electrolytic corrosion in the fuel supply pipe using the stainless steel fuel supply pipe main body. This suppresses or prevents partial electrolytic corrosion. Examples of the electrodeposition paint used for the coating include acrylic paints, alkyd paints, urethane paints, and epoxy paints provided as cationic aqueous solutions or emulsions. In addition, Patent Document 2 provides partial electrolytic corrosion of the oil supply pipe body by providing a sacrificial electrode containing zinc on the oil supply pipe body or the attachment member while the oil supply pipe body and the attachment members are all made of stainless steel. Suppressed or prevented.

JP 2002-242779 A JP 2005-206064 A

  The fuel supply pipe of Patent Document 1 is considered to be able to suppress or prevent partial electrolytic corrosion of the fuel supply pipe body made of stainless steel as long as a coating film by cationic electrodeposition coating exists. However, it is impossible to suppress or prevent electrolytic corrosion of the portion where the passive film is damaged due to the peeling of the coating film over time. Further, as described above, since the electrolyte deposited in the gap portion is concentrated, there is a risk that electrolytic corrosion will still occur even if there is a passive film. Furthermore, electrodeposition coating over the entire oil supply pipe body is costly and is not a very preferred rust prevention technique for automobile members that are required to be reduced or reduced in cost.

  On the other hand, the fuel oil supply pipe of Patent Document 2 is made of stainless steel in which the oil supply pipe main body and the accessory member each have excellent corrosion resistance, and a sacrificial electrode that suppresses or prevents the loss of the passive film of the stainless steel is provided. Since it is provided, it is easy to suppress or prevent partial electrolytic corrosion, and it is only necessary to partially provide a sacrificial electrode, so that an increase in cost can be suppressed. However, the use of stainless steel for the attachments creates a new cost increase, and if the attachment is a mounting bracket to the vehicle body, then partial electrolytic corrosion between the normal steel vehicle body and the mounting bracket. May occur. Therefore, based on the technical idea of Patent Document 2 instead of Patent Document 1, it is possible to suppress or prevent electrolytic corrosion of the oil supply pipe body, the accessory member, and further the vehicle body while suppressing the increase in cost by partial measures as much as possible. In order to provide a fuel refueling pipe that can be used.

  As a result of the study, the fuel oil pipe that was developed by attaching a mounting bracket and other attachments to the vehicle body to the stainless steel oil supply pipe body, and the attachment parts attached to the stainless steel oil supply pipe body are usually steel. A fuel oil supply pipe made of galvanized at least a portion in contact with the main oil supply pipe body of the accessory member. The accessory member includes a mounting bracket that is attached to fix the position of the oil supply pipe body to the vehicle body, a mounting flange that positions and fixes the oil supply port, and a support bracket for the blister pipe.

  In the present invention, since the accessory member welded or brazed to or near the plastic-processed portion of the oil supply pipe body is attached to a portion where partial electrolytic corrosion is likely to occur. Zinc plating and attached members themselves are used as sacrificial electrodes. First, galvanization interposed between a stainless steel oil supply pipe body and a normal steel accessory member is electrolytically corroded prior to the oil supply pipe body as a sacrificial electrode for the oil supply pipe body. Then, when the electrolytic corrosion of galvanization is finished, this time, the normal steel accessory member is electrolytically corroded before the oil supply pipe body as a sacrificial electrode. Thus, electrolytic corrosion occurs in the order of galvanization, accessory member, and oil supply pipe body, thereby suppressing or preventing partial electrolytic corrosion of the oil supply pipe body. Here, since the attachment member is made of the same normal steel as the vehicle body, there is an advantage that electrolytic corrosion is unlikely to occur between the attachment member and the vehicle body.

  As described above, the fuel supply pipe of the present invention suppresses or prevents partial electrolytic corrosion of the fuel supply pipe main body by delaying the order of electrolytic corrosion of the fuel supply pipe main body after the galvanization and the attached member. From this, the corrosion resistance of the oil supply pipe body can be further improved if the galvanization and the electrolytic corrosion of the accessory are difficult to occur. From this, it is desirable that the entire accessory member is galvanized, and further, the whole including the galvanization is rust-proofed. Examples of the antirust coating include electrodeposition coating and powder coating. These rust preventive coatings prevent electrolytic corrosion of the oil supply pipe body by suppressing electrolytic corrosion of the accessory member, and therefore may be used only for the accessory member. For this reason, compared with the case where antirust coating is applied to the oil supply pipe body, the increase in cost is greatly suppressed.

  In the present invention, since the accessory member welded or brazed to or near the plastic-processed portion of the oil supply pipe body is attached to a portion where partial electrolytic corrosion is likely to occur. By using the galvanized plating and the accessory member itself as a sacrificial electrode, electrolytic corrosion of the fuel supply pipe body is extremely difficult to occur, and a high rust prevention effect is brought about in the fuel supply pipe. The rust prevention effect can be further enhanced by galvanizing the entire attachment member or by further applying a rust prevention coating to prevent corrosion of the attachment member. Such galvanization and anticorrosion coating require only an accessory member, so that an increase in cost is suppressed. In addition, since the attachment member itself is made of the same normal steel as the vehicle body, the present invention also has a secondary effect of suppressing or preventing electrolytic corrosion between the attachment member and the vehicle body.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing the entire fuel supply pipe 1 to which the present invention is applied, FIG. 2 is an end view of the AA cross section in FIG. 1, and FIG. 3 is an enlarged end view taken along the arrow B in FIG. .

  As shown in FIG. 1, the fuel refueling pipe 1 of this example is a composite in which attachment members such as a mounting bracket 12 for a vehicle body, a mounting flange 13 for a refueling port, and a support bracket 15 for a blister pipe 14 are attached to a fueling pipe main body 11. It is a product. In this example, the oil supply pipe body 11 and the blister pipe 14 are made of stainless steel, and attachment members such as the mounting bracket 12, the mounting flange 13, and the support bracket 15 are made of normal steel, and the entire surface of each of the attachment members is galvanized. (See FIG. 2). Further, the fastening bolt 16 for fastening the mounting bracket 12 to the oil supply pipe body 11 is made of galvanized steel.

If the mounting bracket 12 is taken as an example, as shown in FIGS. 2 and 3, the mounting bracket 12 can be visually recognized from the outside when it is attached to the oil supply pipe main body 11 and the outer surface (the surface that contacts the oil supply pipe main body 11). The galvanized surface 121 formed on the entire surface including the surface) is interposed between the surface of the oil supply pipe body 11 and the inner surface of the mounting bracket 12, and exhibits a function equivalent to a so-called sacrificial electrode. As a result, in the portion of the oil supply pipe body 11 to which the mounting bracket 12 is attached, first, the galvanized surface 121 of the mounting bracket 12 is electrolytically corroded, then the steel mounting bracket 12 is electrolytically corroded, and the stainless steel oil supply pipe Electrolytic corrosion of the main body 11 can be suppressed or prevented. The thickness D ₁ of the galvanized surface 121 that functions as a sacrificial electrode is preferably 3 μm to ₁₃ μm.

  Further, the galvanized surface 121 existing on the entire surface including the inner surface and the outer surface of the mounting bracket 12 suppresses or prevents electrolytic corrosion of the mounting bracket 12. In addition, if the anticorrosion coating surface 122 is formed by cationic electrodeposition including the galvanization 121, the electrolytic corrosion of the mounting bracket 12 can be further suppressed or prevented. In this example, it is assumed that the portion of the fuel supply pipe 1 to which the mounting bracket 12 is attached including the fuel supply pipe main body 11 is subjected to cationic electrodeposition coating, and FIG. 3 shows the antirust coating surface 122 only on the outer surface side of the mounting bracket 12. ing.

The thickness D ₂ of the anticorrosion coating surface 122 formed by electrodeposition coating as in this example is preferably 10 μm to 25 μm. Here, in cationic electrodeposition coating, a cationic aqueous solution or emulsion such as an acrylic paint, an alkyd paint, a urethane paint, or an epoxy paint can be used. Also, if the anticorrosive coating surface 122 is formed by powder coating, the thickness D ₂ is 40μm~120μm is preferred. Paints that can be used for this powder coating include polyester paints, epoxy paints, acrylic paints, hybrid paints of polyester and epoxy, and modified EVA paints. Each painting uses various conventionally known means.

  In addition, in this example, since the fastening bolt 16 for fastening the mounting bracket 12 to the oil supply pipe body 11 is made of galvanized steel, the galvanized surface 121 is subject to electrolytic corrosion prior to the fastening bolt 16. Thus, electrolytic corrosion of the fastening bolt 16 can be suppressed or prevented. Further, for a vehicle body made of steel (not shown), the galvanized surface 121 precedes the electrolytic corrosion even between the mounting bracket 12 made of the same steel, thereby suppressing or preventing the electrolytic corrosion of the vehicle body. . However, since the mounting bracket 12 and the vehicle body have the same configuration, a potential difference is unlikely to occur, and electrolytic corrosion of the vehicle body can be suppressed or prevented.

It is a perspective view showing the whole fuel supply pipe to which the present invention is applied. It is an end view of the AA cross section in FIG. FIG. 3 is an enlarged end view as viewed from an arrow B in FIG. 2.

Explanation of symbols

1 Fuel supply pipe
11 Lubrication pipe body
12 Mounting bracket
121 Galvanized surface
122 Rust-proof painted surface
13 Mounting flange
14 Blister tube
15 Support bracket
16 Tightening bolt

Claims (5)

In a fuel supply pipe constructed by attaching an attachment member such as a mounting bracket for the vehicle body to a stainless steel supply pipe body,
A fuel supply pipe characterized in that an attachment member attached to a stainless steel supply pipe body is made of normal steel, and at least a portion of the attachment member that contacts the supply pipe body is galvanized. The fuel supply pipe according to claim 1, wherein the attachment member is entirely galvanized. The fuel supply pipe according to claim 1, wherein the attachment member is entirely rust-proofed including galvanization. The fuel supply pipe according to claim 3, wherein the rust-proof coating is an electrodeposition coating. The fuel supply pipe according to claim 3, wherein the antirust coating is powder coating.

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