JP2860318B2 - Terminal structure of resin-coated steel pipe - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a terminal structure of a resin-coated steel pipe, and more particularly to a terminal structure of a resin-coated steel pipe for improving corrosion resistance and water resistance of the resin-coated steel pipe.

[0002]

2. Description of the Related Art Conventionally, steel pipes are frequently used for various pipes used for automobiles and the like, for example, brake pipes, fuel pipes, and the like. Further, for the purpose of protection from corrosion and the like, a multilayer protective coating layer is formed.

As this multilayer protective coating layer, for example, first, a coating layer of several tens μm consisting of a galvanized layer having a chromate film is formed on the outer peripheral surface of a steel pipe, and an adhesive is formed as an upper layer of the galvanized layer. A resin layer made of a heat-shrinkable resin such as a vinyl chloride resin or a polyolefin resin is thermally shrunk through a tube-shaped coating material made of the heat-shrinkable resin through a steel pipe without or with an adhesive therebetween. What was formed on the surface. Alternatively, as described above, as an upper layer of a galvanized layer or the like, and further as an upper layer of an intermediate layer such as a fluororesin layer, for example, a thermoplastic resin such as nylon, polyethylene, or polypropylene may be used without an adhesive. And a resin layer formed by coating the thermoplastic resin on the surface of a steel pipe by extrusion molding.

Here, in the case of a steel pipe in which the above-mentioned resin layer is the outermost layer of the protective coating layer, the resin layer is used as a countermeasure against impact from hopping stones, pipes which follow complicated paths, or pipes and a vehicle body or other parts. Since it is formed as a measure against interference with parts and further as a measure against heat insulation, the layer thickness is formed relatively thick, and the above resin layer covered when connecting the steel pipe to the rubber hose becomes an obstacle. The resin layer 102 in the vicinity 101a of the end of the steel pipe 101 as shown in FIG.
Was often peeled off and connected to the rubber hose 103 in many cases.

[0005] Therefore, a gap X may be formed between the new protective layer 104 and the lower protective coating layer 104 at the new end portion 102 a of the resin layer 102 from which a part of the resin layer 102 has been peeled off due to a peeling force at the time of peeling. Also, even if the resin-coated steel pipe 101 is mounted on an actual vehicle and repeatedly subjected to a severe temperature change, even if the resin layer 102 is formed via an adhesive, even if the resin-coated steel pipe 101 is used for a long time, Is gradually the resin layer 102
The gap X between the metal layer and the lower protective coating layer 104 extends deeply into the inside, and there is a possibility that rainwater or the like may enter the gap X to promote corrosion of the steel pipe.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the resin-coated steel pipe, and has as its object the purpose of connecting a rubber hose with a part of the resin layer whose part has been peeled off from the end of the resin layer. And the like to prevent intrusion of the resin-coated steel pipe, thereby improving the corrosion resistance and water resistance of the resin-coated steel pipe.

[0007]

In order to achieve the above-mentioned object, the present invention utilizes a rubber hose itself to connect a new end of a resin layer formed by peeling a part thereof. And sealed. That is, the present invention
As the outermost layer of the multilayer protective coating layer formed on the outer peripheral surface of the steel pipe, a resin-coated steel pipe having a relatively thick resin layer formed thereon, and when connecting the resin-coated steel pipe to a rubber hose, In the terminal structure of the resin-coated steel pipe having a structure in which the resin layer near the end of the resin-coated steel pipe serving as a connection portion is connected to a rubber hose, the end of the rubber hose to be connected is provided outside the resin layer in advance. An enlarged step portion having an inner diameter slightly smaller than the diameter is formed, and an end portion of a new resin layer formed by the separation is fitted into the enlarged step portion, and the end portion of the resin layer is brought into a watertight state. The structure was covered.

[0008]

According to the above-mentioned terminal structure of the resin-coated steel pipe according to the present invention, a new end of the resin layer, part of which has been peeled off, is connected to the rubber hose by using the rubber hose itself. Because the structure is covered in a watertight state, even if a gap is formed at a new end of the resin layer due to a peeling force at the time of peeling, rainwater or the like can be prevented from entering from the gap, The effect of making the resin-coated steel pipe excellent in corrosion resistance and water resistance is produced.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the terminal structure of the resin-coated steel pipe according to the present invention will be described in detail based on embodiments.

Here, FIG. 1 is an enlarged longitudinal sectional view of a steel pipe to which a terminal structure of a resin-coated steel pipe according to the present invention is applied. In FIG. 1, 1 is used as, for example, a fuel pipe part of an automobile. The steel pipe 1 has an outer diameter of about 10 mm, and a copper plating layer (not shown) is first formed on the surface of the steel pipe 1.

A zinc plating layer 2 on which a chromate film is formed is coated on the copper plating layer, and a fluororesin layer 3 is formed thereon. Since these copper plating layer, zinc plating layer, and fluororesin layer are extremely thin, they are collectively described as a lower protective coating layer 4 in FIG.

On the outer peripheral surface of the fluororesin layer 3, a resin layer 5 made of a thermoplastic resin such as nylon, polyethylene, or polypropylene is further provided with an adhesive or without an adhesive. It is formed by extrusion as an outer protective coating layer.

The outermost resin layer 5 is formed as a countermeasure against impact from stepping stones, a countermeasure against interference between pipes following complicated paths, or a pipe and a vehicle body or other parts, and a countermeasure against heat insulation. Therefore, the layer thickness is formed to be relatively thick, so that the resin layer 5 coated when the steel pipe 1 is connected to the rubber hose or when the connection terminal 6 is applied to the steel pipe 1 is not obstructed. Near the end of the steel pipe 1
Of the resin layer 5 is peeled off, and the end 5a of the new resin layer 5 is removed.
Exists near the terminal portion 1a of the steel pipe 1.

The end 5a of the new resin layer 5 generated by the peeling is covered in a watertight state by using the rubber hose itself to be connected as shown in FIG.

That is, the structure shown in FIG.
This shows an embodiment of a structure in which a new end 5a of the resin layer 5 is covered in a water-tight state by using a rubber hose 7 connected to the rubber hose 7. The end of the rubber hose 7 in this embodiment has a resin in advance. An enlarged step 7a with an inner diameter slightly smaller than the outer diameter of the layer 5
Is formed, and a new end portion 5a of the resin layer 5 is covered in a watertight state by fitting the resin layer 5 into the enlarged step portion 7a.

Assuming that the new end portion 5a of the resin layer 5 from which a part has been peeled off for connection with the rubber hose as described above is covered in a watertight state by using the rubber hose 7 itself to be connected. Even if a gap X is formed in a new end 5a of the resin layer 5 due to a peeling force at the time of peeling as shown in FIG. 1, rainwater or the like may enter from the gap X. Can be prevented, and a resin-coated steel pipe excellent in corrosion resistance and water resistance can be obtained.

While the embodiments of the present invention have been described above,
The present invention is not limited to the embodiments described above, and various modifications and changes can be made based on the technical concept of the present invention. For example, in the above embodiment, as the lower protective coating layer 4 formed on the surface of the steel pipe 1, a copper plating layer,
Although described with a galvanized layer, and a fluororesin layer,
The plating layer or the baking coating layer is not limited at all, and the outermost resin layer 5 is not limited to a material formed by coating a thermoplastic resin on the surface of a steel pipe by extrusion molding, but also to a heat-shrinkable resin. May be a resin layer formed on the surface of a steel pipe by heat shrinking a tubular coating material.

[0018]

According to the terminal structure of the resin-coated steel pipe according to the present invention described above, a new end of the resin layer whose part has been peeled off for connection to the rubber hose is connected to the rubber hose. Because the structure is covered in a watertight state using itself, it is possible to prevent rainwater and the like from entering from a new end of the resin layer without using any other member, and it has excellent corrosion resistance and water resistance. There is an effect of using a resin-coated steel pipe.

[Brief description of the drawings]

FIG. 1 is an enlarged longitudinal sectional view of a steel pipe to which a terminal structure of a resin-coated steel pipe according to the present invention is applied.

FIG. 2 is a longitudinal sectional view of an embodiment of the terminal structure of the resin-coated steel pipe according to the present invention.

FIG. 3 is a longitudinal sectional view showing a connection state of a conventional resin-coated steel pipe with a rubber hose.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Steel pipe 2 Galvanized layer 3 Fluororesin layer 4 Lower protective coating layer 5 Resin layer 5a New end of resin layer generated by exfoliation 6 Terminal for connection 7 Rubber hose 7a Step with enlarged inner diameter 8 Rubber hose fastener

Claims (1)

(57) [Claims] 1. A resin-coated steel pipe on which a relatively thick resin layer is formed as an outermost layer of a multilayer protective coating layer formed on the outer peripheral surface of a steel pipe, wherein the resin-coated steel pipe is connected to a rubber hose. In doing so, the resin layer near the terminal portion of the resin-coated steel pipe to be the connection portion is peeled off, and in the terminal structure of the resin-coated steel pipe having a structure for connecting to the rubber hose, the end of the rubber hose to be connected is Forming an enlarged step having an inner diameter slightly smaller than the outer diameter of the resin layer, and fitting an end of a new resin layer formed by the peeling into the enlarged step; A terminal structure of a resin-coated steel pipe, in which a portion is covered in a watertight state.