JPH11280580A - Fuel piping system for automobile and parts to be used for fuel piping system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel piping system for automobile capable of preventing the destruction of a resin coating layer due to spark by discharging static electricity generated by fluid friction between wall surfaces within a pipe to an engine side or a tank side and parts to be used for the fuel piping system. SOLUTION: In a fuel piping system for automobile constituted by connecting an engine side pipe and a fuel tank side pipe with a fuel pipe 5 having a resin coating layer 5-2 on the outer peripheral surface via a coupling and a resin tube, the fuel pipe 5 is constituted by being electrically conducted and connected with at least one of the engine side pipe or the fuel tank side pipe. Further, a coupling main body is formed by a material having conductivity, a conducting means is interposed between a metallic pipe 5 of the fuel pipe 5 having the resin coating layer 5-2 on the outside surface and this coupling main body, and the conducting means is constituted by peeling off a tip side from an annular swollen wall 5' of the resin coating layer 5-2 provided on the outer peripheral surface of the fuel pipe 5 and bringing the peeled part 5-3 into contact with the coupling main body having conductivity.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel pipe system for connecting an engine and a fuel tank, wherein the fuel pipe system is constituted by connecting an engine side pipe and a fuel tank side pipe to fuel pipes via a joint and a resin tube. The present invention also relates to an automotive fuel piping system and parts used for the piping system.

[0002]

2. Description of the Related Art Conventionally, an engine side and a fuel tank side are connected by a main fuel piping system, a return fuel piping system, and an evaporative fuel piping system, respectively. In general, metal pipes without a resin coating layer are used, but chipping (stepping stones) and splash (muddy water) during running are applied to the outer peripheral surface of fuel pipes etc., which are mainly arranged under the floor of automobiles and the like. ) Was provided with a film-like resin coating layer in order to impart corrosion resistance.

[0003] As a specific example of such a resin-coated metal tube, as necessary, a zinc or zinc / nickel plating layer formed on the outer peripheral surface of the metal tube by an electroplating method such as electric, chemical, or melting is used. A chromate film is formed, and an epoxy-based primer and polyvinyl fluoride (PVF) having a thickness of about 20 μm is further coated, and a heat-shrinkable tube is further applied over the entire length to cover the polymer resin. A polyamide-based resin (PA) such as PA11 or PA12 having a thickness of about 200 to 300 μm on a layer formed thereon, or on a zinc or zinc / aluminum plating layer provided on the outer peripheral surface of a metal tube; Polypropylene (P
What extruded resin such as P) is known.

[0004]

When fuel passes through the fuel pipe system, fluid friction occurs between the fuel pipe and the inner wall of the pipe, thereby generating static electricity. On the other hand, connect the engine side pipe and the fuel tank side pipe to the resin tube,
Also, since the joint for connecting each resin tube to the fuel pipe is usually formed of a resin material and thus has insulation properties, the resin tube used for the fuel piping system also includes a rubber tube or a nylon tube. It is also insulating. Therefore, the static electricity generated by the fluid friction with the inner wall surface of the pipe as described above remains charged without being discharged in the joint or the resin tube. The rubber tube used as the resin tube usually has a thickness of about 3 mm, and the nylon tube has a thickness of about 1 mm.

[0005] On the other hand, fuel pipes and the like generally have conductivity because they are made of metal pipes such as steel.
The film-like resin coating layer applied to the outer peripheral surface makes the whole insulating. Now, as described above, the static electricity generated by the fluid friction between the inner wall of the pipe is gradually charged without being discharged due to the use of an insulating material for the components constituting the fuel pipe system, and is increased to 1000 V or more. When it reaches, a spark is generated in the portion of the resin coating layer on the outer peripheral surface of the fuel pipe having a smaller thickness than the resin tube, which is closest to the vehicle body, and the spark partially destroys the resin coating layer. This broken portion becomes a pinhole in the resin coating layer, and corrosion of the metal pipes such as fuel pipes starts from the pinhole.

SUMMARY OF THE INVENTION It is an object of the present invention to discharge static electricity generated by fluid friction between the pipe and the inner wall of the pipe to an engine or a tank to spark from a fuel pipe or the like to a vehicle body or the like to break the resin coating layer. To prevent corrosion of metal pipes by water, muddy water, snow melting agent, salt water, battery fluid, etc., improve the durability of fuel pipes, and increase the reliability of automotive fuel piping systems and piping systems. It is to provide the parts to be used.

[0007]

In order to achieve the above object, a first embodiment of the present invention is a piping system for connecting an engine and a fuel tank, wherein an engine side pipe and a fuel tank side pipe are connected with a joint and a fuel tank. In a fuel piping system for an automobile, which is connected to a fuel pipe having a resin coating layer on an outer peripheral surface via a resin tube, the fuel pipe may be electrically connected to at least one of an engine-side pipe and a fuel tank-side pipe. The present invention is characterized by a fuel piping system for an automobile configured to be connected.

In a second embodiment of the present invention, the joint body is formed of a conductive material, and a conductive means is provided between a metal pipe of a fuel pipe having a resin coating layer on an outer surface and the joint body. A connecting structure used for a fuel piping system for an automobile, wherein the conductive means is further stripped to an annular bulging wall at least longer than a tip end of a resin coating layer provided on an outer peripheral surface of the fuel pipe. The stripped portion is configured to be in contact with the conductive joint body, and the conductive means is stripped to the annular bulging wall at least longer than the tip end of the resin coating layer provided on the outer peripheral surface of the fuel pipe. The outer peripheral surface of the metal tube at the stripped portion is connected to the conductive joint body by a conductive O-ring, a bush, a combination of an axial spring and a pad, a combination of a radial spring and a steel ball, or a snap ring. Are those composed by electrically conductive is not through at least one.

The conductive means makes the conductive collar contained in the joint body contact the inner peripheral surface of the metal pipe of the fuel pipe, or the conductive collar fitted to the tip of the metal pipe of the fuel pipe. The sleeve is configured to be in contact with the joint body, and the conductive joint body is further connected to a resin tube or an engine-side pipe or a fuel tank-side pipe made of a conductive material, and the joint is It consists of a one-touch connector made of resin mixed with metal or conductive material.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings. FIG. 1 is a schematic view showing an embodiment of an automotive fuel piping system according to the present invention, and FIG. 2 is a partially cutaway longitudinal sectional view of an embodiment of a connecting structure used in the automotive fuel piping system according to the present invention. 3 is an enlarged sectional view of another embodiment of the connection structure, FIG.
FIG. 5 is an enlarged sectional view of still another embodiment of the connection structure, FIG. 5 is an enlarged sectional view of still another embodiment of the connection structure, and FIG. 6 is an enlarged sectional view of still another embodiment of the connection structure. 7 is an enlarged sectional view of still another embodiment of the connecting structure, FIG. 8 is an enlarged sectional view of still another embodiment of the connecting structure, FIG. 9 is an enlarged sectional view of still another embodiment of the connecting structure, FIG. 10 is an enlarged sectional view of still another embodiment of the connection structure, FIG. 11 is an enlarged sectional view of still another embodiment of the connection structure, and FIG. 12 is an enlarged sectional view of still another embodiment of the connection structure. 1 is an engine, 2 is a fuel tank, 3 is an engine side pipe, 4 is a fuel tank side pipe, 5 is a fuel pipe, 6, 6 'are resin tubes, 7a, 7b, 7c, 7d, 8 are resin. Tube 6
And a band member 9 for connecting the resin tube 6 'to the engine side pipe 3 and the fuel pipe 5, respectively, and the resin tube 6' to the fuel tank side pipe 4 and the fuel pipe 5 respectively.

In the present invention, the fuel pipe 5 is an electric resistance welded pipe,
Metal pipes made of seamless pipes, semi-seamless pipes, and brazed pipes or welded pipes that have been preliminarily coated with a copper alloy plating layer and wound into a single layer or multiple layers, for example, steel pipes having a pipe diameter of about 20 mm or less. 5-1
And forming a plating layer such as zinc, zinc / nickel or zinc / aluminum on the outer peripheral surface of the metal tube by a plating method such as electric, chemical or melting, and optionally forming a chromate film on the upper surface of the plating layer. And a resin coating layer 5-2 comprising a polymerized resin layer of an epoxy resin and PVF coated on the outer peripheral surface thereof, and a film-like single layer resin layer made of polypropylene, polyethylene or polyamide resin. It is.

The resin tubes 6 and 6 'are formed by mixing a conductive metal powder or fiber such as copper, brass or silver and a powder or fiber such as carbon into a thermoplastic resin and molding the resin tube. The resin composite tube disclosed in Japanese Patent Application Laid-Open No. Hei 3-69887, proposed by the present applicant, can be used as desired. Further, the fuel tank side pipe 4 has an immersion pipe 4-1 extending to the fuel contained in the fuel tank 2, a pump 4-2 at a lower end of the immersion pipe, and a filter 4-3 near the pump. Are provided respectively.

Next, the fuel pipe 5 and the joints 7a, 7
A description will be given of conductive means for securing an electrical conduction state between the conductive members b, 7c, and 7d. A metal pipe 5-1 whose outer peripheral surface is covered with a resin coating layer 5-2, and joints 7a, 7b, 7c;
In order to secure the electrical conduction state with 7d, first, joint 7
a, 7b, 7c and 7d are made of metal, or mixed with conductive metal powder or fiber such as copper, brass or silver and powder or fiber such as carbon as in the resin tube, into the thermoplastic resin. It is necessary to form a conductive material by molding.

On the other hand, in order to make the fuel pipe 5 conductive, the resin coating layer 5-2 has a required length from the front end side between the front end side and the annular bulging wall portion 5 'formed in the metal tube 5-1. Peel all over. This stripping operation can be performed by buffing or cutting with a wire buff as usual, but as described in Japanese Patent Application No. 9-257689 filed by the applicant of the present invention, the stripping work is radially inward from the outside. The resin coating layer 5-2 is pressed by pressing means, and the metal tube 5-
It is preferable that the pressing member 1 and the pressing means are relatively moved in the circumferential direction and peeled off.

The joint 7 having conductivity as described above
It is preferable to use a one-touch type connector as shown in FIGS. 2 to 11 as a, 7b, 7c and 7d, and to remove the stripped portion 5-3 at the tip of the fuel pipe 5 with the joints 7a, 7b,
7c and 7d are configured to be brought into contact with the flow holes 7-2 of the main body 7-1 so as to electrically conduct the two. However, there is no problem in operation as long as the gap is electrically small without contact. The stripped portion 5-3 is directly connected to the main body 7-1.
Of the small diameter chamber 7-4
The seal ring member 7-5 provided in the above can be made conductive so as to be in close contact with the stripped portion 5-3.

At this time, if a plurality of annular or helical protrusions 7-3 are provided on the inner peripheral surface of the flow hole 7-2 as shown in FIG. The effect of preventing vibration is also obtained.

Further, as shown in FIG. 4, a conductive bush 7-6 is interposed between the stepped portion of the small diameter chamber 7-4 of the joint body 7-1 and the seal ring member 7-5.
6 may be configured to be in contact with the stripped portion 5-3, or as shown in FIG. 5, a conductive bush 7-6 may be provided in the through hole 7-2 to be in contact with the stripped portion 5-3. Such a configuration may be used as the conductive means. Preferably, the conductive seal ring member 7-5 and the conductive bush 7-6 are formed of conductive rubber, and the conductive bush 7-6 in FIG. The effect is also given.

Next, in FIG. 6, the conductive means is connected to the small-diameter chamber 7.
A metal spring 7-7 interposed between the stepped portion of the fuel pipe 5 and the tip of the fuel pipe 5, and a conductive pad 7-8 disposed on the stripped portion 5-3 and urged by the spring. And a combination of the above. As described in Japanese Patent Application Laid-Open No. 3-113193 proposed by the present applicant, a spring may be provided between the tip of the fuel pipe 5 and the stepped portion of the flow hole 7-2, or a seal ring member 7- The conductive means can also be constituted by making the bush to be brought into contact with 5 conductive as described above, and extending a spring between the bush and the step portion of the small diameter chamber 7-4.

Further, in FIG. 7, a spring 7-10 is provided in a hole 7-9 formed in the flow hole 7-2 in the radial direction, and the steel ball 7-11 urged by the spring is attached to the stripped portion 5 as shown in FIG. -3 to form conductive means. FIG. 7
Although a means for preventing the steel balls 7-11 from falling off is not shown in the figure, known preventive means can be employed as appropriate.

FIG. 8 shows an annular groove 7-12 provided on the inner peripheral surface of the flow hole 7-2, and a metal snap ring 7
-13 is fitted, and the snap ring 7-13 contacts the stripped portion 5-3 to constitute a conductive means.

In Examples 2 to 8 described above, the resin coating layer 5-2 of the fuel pipe 5 was peeled off at the tip end side to secure conductivity. However, in the present invention, the stripped portion 5-3 is formed. It can be implemented without doing. That is, a conductive collar 7-14 having a substantially L-shaped cross section as shown in FIG. 9 or a substantially T-shaped cross section as shown in FIG. 10 is pressed against the step portion of the flow hole 7-2 and inserted into the joint body 7-1. The conductive collar is brought into contact with the inner peripheral surface of the metal pipe 5-1 of the fuel pipe 5 to form conductive means.

Further, as shown in FIG. 11, a metal sleeve 5-4 is press-fitted in advance at the tip of the metal pipe 5-1 of the fuel pipe 5, and the fuel pipe 5 thus formed is connected to the joint body 7-1.
And the metal sleeve 5-4 is brought into contact with the communication hole 7-2 of the joint main body 7-1 to form a conductive means. Although the above-described embodiments of FIGS. 2 to 11 have been described individually, they can be used in combination as desired, and Japanese Patent Application Laid-Open No. 7-269765 proposed by the present applicant.
It can also be adopted by appropriately selecting from the components shown in the publication.

FIG. 12 also shows separate joints 7a, 7b, 7
c, 7d without connecting the end of the fuel pipe 5
After the resin coating layer 5-2 is peeled off as described above, the joint 8 is formed with a bulge processing part 8-1 and a spool processing part 8-2 at the peeling part 5-3. The resin tubes 6, 6 'having electrical conductivity are externally fitted to the joint 8, and the resin tubes 6, 6' cross over the bulge processing portion 8-1 and the end faces thereof are spool-processed portions 8--. 2 until it comes into contact with the resin tubes 6, 6 ', and tightened and connected by a band member 9 between the bulge processing portion 8-1 and the spool processing portion 8-2 from outside the resin tubes 6, 6'.
And electrical conduction between the fuel pipe 5 and the fuel pipe 5.
In the embodiment of FIG. 12, the connection between the fuel pipe 5 and the resin tubes 6, 6 'has been described. However, since the engine-side pipe 3 and the fuel-tank-side pipe 4 are each formed of a metal pipe, It goes without saying that the connection structure described above can be applied without any change.

[0024]

As described above, according to the method of the present invention, the static electricity generated by the fluid friction with the pipe inner wall surface is discharged to the engine side or the tank side to spark from the fuel pipes to the vehicle body or the like. Provide a fuel piping system for automobiles and a component used for the piping system that can prevent the resin coating layer from being destroyed and prevent corrosion of metal pipes by water, muddy water, snow melting agent, salt water, battery fluid, and the like. can do.

[Brief description of the drawings]

FIG. 1 is a schematic view showing one embodiment of an automotive fuel piping system according to the present invention.

FIG. 2 is a partially cut-away longitudinal sectional view of one embodiment of a connection structure used for an automotive fuel piping system according to the present invention.

FIG. 3 is an enlarged sectional view of another embodiment of the connection structure used in the fuel piping system for an automobile according to the present invention.

FIG. 4 is an enlarged sectional view of still another embodiment of the connection structure used for the fuel piping system for an automobile according to the present invention.

FIG. 5 is an enlarged sectional view of still another embodiment of the connection structure used for the fuel pipe system for a vehicle according to the present invention.

FIG. 6 is an enlarged sectional view of still another embodiment of the connection structure used for the fuel pipe system for an automobile according to the present invention.

FIG. 7 is an enlarged sectional view of still another embodiment of the connection structure used for the fuel pipe system for an automobile according to the present invention.

FIG. 8 is an enlarged sectional view of still another embodiment of the connection structure used for the fuel piping system for an automobile according to the present invention.

FIG. 9 is an enlarged sectional view of still another embodiment of the connection structure used for the fuel piping system for an automobile according to the present invention.

FIG. 10 is an enlarged cross-sectional view of still another embodiment of the connection structure used for the fuel piping system for an automobile according to the present invention.

FIG. 11 is an enlarged cross-sectional view of still another embodiment of the connection structure used for the fuel piping system for an automobile according to the present invention.

FIG. 12 is an enlarged sectional view of still another embodiment of the connection structure used for the fuel piping system for an automobile according to the present invention.

[Explanation of symbols]

 Reference Signs List 1 engine 2 fuel tank 3 engine side pipe 4 fuel tank side pipe 4-1 immersion pipe 4-2 pump 4-3 filter 5 fuel pipe 5 'annular bulging wall 5-1 metal pipe 5-2 resin coating layer 5-3 Stripped portion 5-4 Sleeve 6, 6 'Resin tube 7a, 7b, 7c, 7d, 8 Joint 7-1 Main body 7-2 Flow hole 7-3 Projection 7-4 Small diameter chamber 7-5 Seal ring member 7- 6 conductive bush 7-7 metal spring 7-8 conductive pad 7-9 hole 7-10 spring 7-11 steel ball 7-12 concave groove 7-13 metal snap ring 7-14 conductive collar 8-1 bulging Part 8-2 Spool processing part 9 Band member

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[Procedure amendment]

[Submission date] April 28, 1998

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] Fig. 6

[Correction method] Change

[Correction contents]

FIG. 6

[Procedure amendment 2]

[Document name to be amended] Drawing

[Correction target item name] Fig. 7

[Correction method] Change

[Correction contents]

FIG. 7

Claims (7)

[Claims] 1. A piping system for connecting an engine and a fuel tank, wherein the engine side pipe and the fuel tank side pipe are connected to a fuel pipe having a resin coating layer on an outer peripheral surface via a joint and a resin tube. A fuel piping system for an automobile, wherein the fuel pipe is connected to at least one of an engine-side pipe and a fuel-tank-side pipe so as to be electrically conductive. 2. The joint body is formed of a conductive material, and conductive means is interposed between a metal pipe of a fuel pipe having a resin coating layer on an outer surface and the joint body. Connection structure used in automotive fuel piping systems. 3. The conductive means peels off at least the annular bulging wall longer than the tip end of a resin coating layer provided on the outer peripheral surface of the fuel pipe, and brings the stripped portion into contact with the conductive joint body. 3. A connection structure for use in an automotive fuel piping system according to claim 2, wherein the connection structure is configured. 4. The conductive means peels off the outer peripheral surface of the metal tube at the stripped portion at least from the tip end side of the resin coating layer provided on the outer peripheral surface of the fuel pipe to the annular bulging wall. The coupling body is electrically connected to at least one of a conductive O-ring, a bush, a combination of an axial spring and a pad, a combination of a radial spring and a steel ball, or a snap ring. A connection structure for use in an automotive fuel piping system according to claim 2, characterized in that: 5. The conductive means makes the conductive collar contained in the joint body come into contact with the inner peripheral surface of the metal pipe of the fuel pipe, or the conductive collar fitted inside the tip of the metal pipe of the fuel pipe. 3. The connection structure for use in an automotive fuel piping system according to claim 2, wherein a conductive sleeve is configured to contact the joint body. 6. The vehicle according to claim 2, wherein a resin tube, an engine-side pipe, or a fuel tank-side pipe made of a conductive material is further connected to the conductive joint body. Connection structure used for fuel piping system. 7. The fuel piping system for an automobile according to claim 2, wherein the joint comprises a one-touch connector made of a resin mixed with a metal or a conductive material. The connection structure to use.