WO2005052350A1

WO2005052350A1 - Fuel tube and earth structure of vehicle fule piping

Info

Publication number: WO2005052350A1
Application number: PCT/JP2004/016594
Authority: WO
Inventors: Takanori Kon
Original assignee: Sanoh Kogyo Kabushiki Kaisha
Priority date: 2003-11-28
Filing date: 2004-11-09
Publication date: 2005-06-09
Also published as: JP4439889B2; JP2005155572A

Abstract

A fuel tube requiring no special components for peeling off part of resin coating or grounding and allowing static electricity to escape to the vehicle body side. The fuel tube comprises a metal rough pipe (13) coated on the outer peripheral surface thereof with multi-layer coating, wherein the multi-layer coating consists of an inner-most-side layer of plated coating (14), and an outer-layer conductive resin coating (18).

Description

Specification

Ground structure of fuel tube and vehicle fuel pipe

Technical field

The present invention relates to a fuel tube used for a vehicle fuel pipe for supplying fuel to an engine and an earth structure of the vehicle fuel pipe.

Background art

[0002] A fuel tube used for a vehicle fuel pipe is required to have corrosion resistance and chemical resistance. Therefore, an outer peripheral surface of the raw tube is coated with zinc, and the outer surface of the tube is coated with a chromate diversion coating film. And other electrolytic and electroless chemical conversion treatments.

[0003] In general, vehicle fuel piping extends to the engine by routing the lower side of the vehicle body, and it is necessary to improve chipping resistance so that pebbles and the like splashed during traveling do not damage the resin film. is there. Also, it is relatively thick to prevent the resin film from being damaged by rubbing pipes that follow complicated paths, vehicle bodies or other parts.ヽ榭 A resin film is often provided on the outermost layer. Conventionally, as a material for a resin film of a fuel tube, PVdF or PVF, which is mainly a fluorine resin, has been used.

[0004] In recent years, the demand for the service life of the fuel tube has become more and more strict. In particular, automobiles intended for areas with heavy snowfall are not affected by salt and potassium which are sprayed on roads to prevent freezing. Strong chemical resistance is required.

[0005] In order to meet such a demand, a fuel tube covered with a resin film made of PA resin has been used. Therefore, Fig. 7 shows a cross section of this type of fuel tube. In FIG. 7, reference numeral 1 denotes a raw pipe 1 made of steel pipe. The outer peripheral surface of the tube 1 is covered with a Zn plating film 2. The surface of the Zn film 2 is subjected to a chromate conversion treatment, and a primer 3 is applied and baked thereon as a pretreatment for coating with a resin film. Overlying the primer 3, for example, a PP film 4 made of a polyphenylene resin and a PA film 5 made of a polyamide resin are coated.

Disclosure of the invention

Problems the invention is trying to solve [0006] In a conventional vehicle fuel pipe, there is a phenomenon that when a pump discharges fuel from a fuel tank, static electricity is generated due to friction due to flow path resistance of the fuel tube, and the fuel tube is charged. In the case of the fuel tube shown in FIG. 6, since both the PP coating 4 and the PA coating 5 are non-conductive, if there is no escape for static electricity, dielectric breakdown or spark discharge may occur. Dielectric breakdown and spark discharge will damage the coating of the fuel tube, so it is necessary to ground and discharge static electricity.

[0007] In a vehicle fuel pipe, where a metal flare nut is used as a joint, the flare nut and the raw pipe are electrically connected. In this case, the static electricity can be released, and there was no problem of damage to the film due to spark generation.

[0008] However, in recent years, resin-made joints, which do not use any metal as joints, have become widespread. If such joints are used, dielectric breakdown or sparking where there is no place for static electricity to escape is performed. Discharge cannot be prevented. Therefore, conventionally, as shown in FIGS. 8 and 9, a part of the resin film is peeled off and grounded.

Fig. 8 shows a part of the PP resin 4 and PA coating 5 that are peeled off to provide an exposed part 6 of the metal surface or the plated surface, and a conductive rubber, such as a conductive rubber, that closely covers the surface of the PA coating 5. This is a conventional example in which a masking member 7 made of EPDM rubber is covered. On the inner peripheral surface of the masking member 7, a projection 8 reaching the exposed portion 6 is formed. Therefore, by using the masking member 7 to ground the vehicle body and the conductor 9 to ground, static electricity generated in the fuel tube can be released to the vehicle body.

[0009] Next, Fig. 9 shows that instead of peeling off a part of the PP resin 4 and the PA film 5 and covering the masking member 7, a conductive cap 10 which also has a conductive material such as a metal at the tip of the fuel tube. This is a conventional example of a grounding structure in which a conductive resin tube 11 made of conductive resin is attached to a conductive cap 10 by press-fitting while being attached. In this case, since the metal surface is exposed at the end face of the fuel tube, the conductive resin tube 11 that does not peel the resin film is grounded to the vehicle body with the conductor 9 to discharge the static electricity generated in the fuel tube to the vehicle body. You can escape.

[0010] However, when a part of the resin film is peeled, it is necessary to peel the plating film covering the raw tube so as not to damage the chromate film, which requires a complicated processing step. At the same time, water or the like penetrates into the peeled portion, causing corrosion. In addition, when a component such as a conductive cap is used, the number of components increases, and the cost increases.

[0011] Therefore, an object of the present invention is to solve the above-mentioned problems of the prior art, and to dissipate static electricity on the vehicle body side without removing a part of the resin coating or requiring a special part for grounding. Another object of the present invention is to provide a ground structure for a fuel tube and a vehicle fuel pipe which can escape to a vehicle.

[0012] Another object of the present invention is to provide a ground structure for a fuel tube and a vehicle fuel pipe which can prevent the progress of corrosion caused by the transfer of electrons to the resin film. It is in.

Means for solving the problem

[0013] In order to achieve the above object, the present invention provides a fuel tube in which the outer peripheral surface of a metal pipe is coated in multiple layers with a coating, wherein the multi-layer coating is an innermost plating film and an outer layer. Characterized by comprising a conductive resin film.

[0014] Further, the present invention provides a fuel tube in which an outer peripheral surface of a metal pipe is coated with a multilayer coating, wherein the multilayer coating comprises an innermost plating coating and a surface resin coating.榭 The resin film is made of conductive resin.

[0015] According to the invention, it is possible to ground so that static electricity can escape to the vehicle body side without removing a part of the resin coating or special components for grounding.

Further, according to the present invention, it is possible to prevent the progress of corrosion caused by the transfer of electrons to the resin film.

Brief Description of Drawings

FIG. 1 is a cross-sectional view showing a fuel tube according to a first embodiment of the present invention.

FIG. 2 is an explanatory view of a first example of a ground structure when the fuel tube of FIG. 1 is used for a fuel pipe.

FIG. 3 is an explanatory view of a second example of the ground structure when the fuel tube of FIG. 1 is used for a fuel pipe.

FIG. 4 is an explanatory view of a third example of the ground structure when the fuel tube of FIG. 1 is used for a fuel pipe. FIG. 5 is a cross-sectional view showing a fuel tube according to a second embodiment of the present invention.

FIG. 6 is a cross-sectional view showing an example of a fuel tube grounding structure according to a second embodiment of the present invention.

FIG. 7 is a cross-sectional view showing a conventional fuel tube.

FIG. 8 is an explanatory view showing a conventional earth structure of a fuel pipe.

FIG. 9 is an explanatory view showing another example of a conventional earth structure of a fuel pipe.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, an embodiment of a fuel tube according to the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a cross-sectional view of a fuel tube according to a first embodiment of the present invention. In FIG. 1, reference numeral 12 indicates a fuel tube, and 13 indicates a raw tube. Preferably, a single-wound steel pipe or a double-wound steel pipe is used as the raw tube 13.

[0018] The entire outer peripheral surface of the raw tube 13 is covered with a Zn plating film 14, and a chromate film (not shown) is formed on the Zn plating film 14 by a chemical conversion treatment. Further, the surface of the mouth mate film is coated with a primer film 16 for the resin film so as to enhance the adhesiveness with the resin film. The primer film 16 may be formed by applying a primer agent and baking force, or may be formed by extrusion molding. The chemical conversion coating is not limited to the chromate coating, and may be, for example, a phosphoric acid coating.

The outermost layer on the primer film 16 is a conductive resin film 18. The conductive resin film 18 is a resin provided with conductivity by mixing a conductive material such as carbon fiber with a polyamide (PA) resin. The coating of the conductive resin film can be performed by an extrusion molding method or a powder coating method.

[0020] According to the fuel tube 12 coated with the conductive resin film 18, the conductive resin film 18 does not insulate the base tube 13 unlike the conventional resin film, so that the conductive resin film 18 does not insulate the conductive tube 13. A conductive wire or the like can be attached to the conductive resin film 18 without peeling a part of the resin film 18 and grounded. This not only prevents damage to the coating due to static electricity discharge sparks, but also enhances the inherent properties of PA resin to enhance its durability against salt damage and chipping resistance. An excellent fuel tube can be obtained.

[0021] The conductive resin film 18 described above has a specific resistance value representing the magnitude of the electric resistance, for example, about 10 ⁴ Ω'cm, and has a property as a conductor. On the other hand, by adjusting the content of conductive materials such as carbon fiber to be mixed, the electrical properties of the resin film are adjusted so as to have an electrical resistance between a conductor and an insulator, that is, a semiconductor equivalent. It is also possible to have such a characteristic.

In FIG. 1, a resin film 18 (hereinafter, referred to as a resin film 18 when having conductivity and a resin film 18 ′ when having properties of a semiconductor) is located between the conductor and the insulator. If the fuel tube 12 made of a PA system榭脂having a specific resistance of regions in which 10 ⁶ one 10 ^omega omega 'cm, it is possible to obtain a new effect as follows.

As described above, when the resin coating 18 has conductivity, the base tube 13 and the resin coating 18 are electrically connected to the base tube 13, so that the base tube 13 and the resin tube are always connected even when static electricity escapes. Electron transfer occurs with the coating 18. The fact that electrons are transferred means that Fe constituting the raw tube 13 and Zn of the Zn plating film 14 are ionized. If the bare tube 13 and the Zn plating film 14 have very slight scratches or the like from the beginning, corrosion may progress due to ionization.

[0024] On the other hand, if the resin film 18 'is neither an insulator nor a conductor, the static electricity accumulates and if the potential increases, the static electricity escapes through the resin film 18'. No current flows during the period. That is, since there is usually no transfer of electrons, the progress of corrosion due to ionization can be suppressed, and when static electricity accumulates, static electricity can be discharged, so that both the earth discharge action and the corrosion suppression action can be achieved.

Next, FIGS. 2 to 4 are diagrams showing grounding methods when the fuel tube 12 of FIG. 1 is used for a fuel pipe of an automobile.

FIG. 2 shows an example in which the fuel tube 12 is directly grounded to the vehicle body. The fuel tube 12 of the first embodiment can be directly grounded to the vehicle body by using a conductor 20 that needs to peel off the outermost resin coatings 18 and 18 '.

Next, FIG. 3 shows an example of grounding using a stay 22 for fixing the fuel tube 12 to the vehicle body. In this case, the stay 22 is made of a metal material. Therefore, by connecting the stay 22 to the vehicle body with the conducting wire 20, the ground can be directly provided. FIG. 4 shows an example in which a resin tube 24 made of a conductive resin is connected to the fuel tube 12, and the resin tube 24 is connected to a vehicle body via a conductor 20 and grounded. In this example, the end of the fuel tube 12 has a straight end shape. In order to increase the press-fit connection strength with the force tube 24, the spool portion and the like may be processed by end processing as necessary. .

[0029] As described above, the outermost layer of the fuel tube 12 is made of the resin film 18 or 18 ', so that the parts required for grounding are not particularly required, and the grounding position and the equipment around the fuel pipe are not required. Depending on the installation situation, a suitable one can be selected from the ground structures shown in FIGS.

Next, FIG. 5 is a diagram showing a cross section of a fuel tube 30 according to a second embodiment of the present invention.

The first embodiment of FIG. 1 is different from the first embodiment in that a resin material in which a conductive material such as carbon fiber is mixed with PP resin (polypropylene resin) is superimposed on a resin film 18 or 18 ′ made of PA resin. This means that the protective resin film 32 has been coated. In other respects, there is no difference from FIG. 1, and the same components are denoted by the same reference numerals and description thereof will be omitted.

According to the fuel tube 30 of the second embodiment, the ground structure shown in FIG. 4 is effective when the fuel tube 12 is a quick spool type connection terminal as shown in FIG. is there.

That is, the PA resin resin films 18 and 18 ′ are covered with the protective resin film 32 except for the terminal portions, and the resin films 18 and 18 ′ become the surface layer at the terminal portions. The area that is not covered with the protective resin film 32 at this end portion is to allow for the chucking fee required when spooling the spool 33.

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As shown in FIG. 6, a mating tube 34 made of a conductive resin is connected to the terminal portion of the fuel tube 30 having the spool portion 33 formed by press fitting. Then, the other tube 34 may be grounded. As described above, in the fuel tube 30, it is possible to achieve both easy grounding to the vehicle body without peeling the outermost protective resin film 32 and enhancement of durability by the protective resin film 32. Become.

[0034] The fuel tube according to the present invention has been described with reference to the preferred embodiment. When the fuel tube of the present invention is used for a fuel pipe, it can be easily grounded by a method other than the ground structure shown in FIGS. For example, when a quick connector is connected to the fuel tube 12, the quick connector itself is made of a conductive material and an O-ring that also has a conductive rubber force is used, so that the quick connector force can be easily reduced. Can be taken.

Claims

The scope of the claims

[1] In a fuel tube in which the outer peripheral surface of a metal tube is coated with a multilayer coating,

The multilayer coating,

The innermost coating film,

With a surface resin film,

The resin film is made of conductive resin.

A fuel tube, characterized in that:

[2] In a fuel tube in which the outer peripheral surface of a metal tube is coated with a multilayer coating,

The multilayer coating,

The innermost coating film,

With a surface resin film,

The resin film has an electrical resistance equivalent to that of a semiconductor material

A fuel tube, characterized in that:

[3] The surface layer of榭脂coating has a specific resistance of 10 ⁶ - fuel tube according to claim 2, 10 ^1Q Q 'cm feature in that it consists of PA system榭脂of.

[4] Covered with PA resin film via primer film

4. The fuel tube according to claim 3, wherein:

[5] The resin film made of the PA resin was coated with a protective film made of the PP resin except for the end of the tube.

5. The fuel tube according to claim 3, wherein:

[6] A chemical conversion coating was provided between the paint coating and the resin coating.

The fuel tube according to any one of claims 1 to 4, characterized in that:

[7] The chemical conversion coating is a chromate coating or a phosphoric acid coating.

7. The fuel tube according to claim 6, wherein:

[8] The primer film is a film formed by applying a primer agent and baking with force, or a film formed by coating by extrusion molding.

5. The fuel tube according to claim 4, wherein:

[9] The resin film forms an outermost layer of the multilayer film. The fuel tube according to claim 1, wherein:

[10] A protective resin film is coated on the outside of the resin film.

The fuel tube according to claim 1, wherein:

[11] The protective resin film is made of a resin material obtained by mixing a conductive material with a polypropylene resin.

11. The fuel tube according to claim 10, wherein:

[12] The fuel tube according to any one of claims 1 to 11 is directly brazed to the vehicle body.

An earth structure for a vehicle fuel pipe.

[13] The fuel tube according to any one of [1] to [11] is indirectly grounded to the vehicle body via a fixing member made of a conductive material.

An earth structure for a vehicle fuel pipe.

[14] The fuel tube according to any one of claims 1 to 11, wherein the fuel tube is indirectly grounded to a vehicle body via a piping member made of a conductive material.

An earth structure for a vehicle fuel pipe.