JPH0560280A - Connecting structure of hose - Google Patents

Abstract

PURPOSE:To increase the fastening strength and sealing force of a hose by forming a ring protruding part bitten into the hose on the inner circumferential surface of the end part of a resin cover part. CONSTITUTION:A pipe member 2 is formed of a cylinder part 20 having a plurality of ring projections 21 for stopping on the surface and a thick part 22 in the middle. The pipe member 2 in which hoses 1 are inserted to three cylinder parts 20 is put in a molding die. In the end part of the cavity, then, the hoses 1 are compressed by a ring seal core to form a ring recessed part contracted in diameter into a tapered form. A fused resin is injected into the cavity to form a resin cover part 3. The resin is then charged in the ring recessed part, and a ring protruding part 30 of the form bitten into the hose 1 is formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a connecting structure for a hose mainly used in a branch portion such as a two-way branch hose and a three-way branch hose.

[0002]

2. Description of the Related Art Conventionally, as a hose connection structure, for example, one disclosed in Japanese Patent Laid-Open No. 62-233591 is known. As shown in FIG. 5, this connection structure has branch pipes 100 that branch in three directions, and hoses 201 and 202 inserted into the branch pipes of the branch pipes 100, respectively.
203, and a resin coating portion 300 that covers the joint between the hose and the branch pipe.

In order to form this hose connection structure, the branch pipes of the branch pipe 100 are respectively connected to the hoses 201 to 203.
To insert. Then each hose and branch pipe 10
The joint portion of 0 is arranged in the mold, and the resin covering portion 300 is formed on the joint portion by molding. At this time, since the resin coating portion 300 contracts and solidifies at a contraction rate of 0.5% or more, a diameter reducing force acts on each hose. As a result, each hose is strongly sandwiched between the resin coating portion 300 and the branch pipe 100, and a high sealing pressure is obtained.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to further improve the fastening strength of a hose in a connection structure such as the above hose connection structure.

[0005]

A hose connection structure of the present invention which solves the above problems has a pipe member inserted in a hose having an annular projection for preventing the surface from coming off, and the entire connecting portion between the hose and the pipe member. In a connection structure of a hose consisting of a resin-made coating portion which is coated on the circumference and formed by molding, the resin-made coating portion has an annular convex portion that bites into the hose on the inner peripheral surface of the end portion. Connection structure.

The hose connection structure of the present invention comprises a pipe member, a hose, and a resin coating portion. As the hose, various hoses can be used as in the conventional case. Above all, it is preferable to use a reinforcing hose having a reinforcing yarn layer braided in the middle. The pipe member is inserted into the hose to form a flow path. The number of branches is not limited, and various branch structures can be used. On the surface of the end of the pipe member that is inserted into the hose, a ring-shaped projection for retaining is formed as in the conventional case.

The resin coating portion is the same as the conventional one, which is formed by molding over the entire circumference of the connecting portion between the hose and the pipe member. The greatest feature of the present invention is that the resin coating portion has an annular convex portion that bites into the hose on the inner peripheral surface of the end portion. By sandwiching the hose in a compressed state between the annular convex portion and the surface of the pipe member, the fastening strength can be further improved. It is desirable that the annular convex portion is located at a position facing the annular protrusion on the surface of the pipe member. This compresses the hose more strongly,
Further, the fastening strength is improved.

The resin coating may be divided into a plurality of parts along the axial direction of the pipe member. In this case, the annular convex portion can be formed at the end of each divided covering portion, and a plurality of annular convex portions are formed. Further, since it does not look good when divided, it is possible to further form a coating layer so as to cover the entire resin coating portion.

In order to form the annular convex portion, the resin coating portion is molded while the hose surface is pressed against the pipe member by the mold. At this time, since the outer diameter of the portion of the hose adjacent to the pressing portion is smaller than that of the other portion of the hose, an annular convex portion is formed at that portion. After the molded body is solidified, the pressure on the hose is released, whereby the hose elastically deforms, and the annular convex portion bites into the hose.

[0010]

In the hose connection structure of the present invention, the resin-coated portion is formed with an annular convex portion that bites into the hose on the inner peripheral surface of the end portion. As a result, a large radial compressive force acts on the hose between the pipe member and the annular convex portion, and the fastening strength and the sealing force increase.

Further, the annular convex portion can be easily formed at the same time when the resin coating portion is formed, and the number of steps is not increased. Therefore, it is possible to provide a hose connection structure that is inexpensive and has excellent fastening strength.

[0012]

Embodiments will be specifically described below with reference to embodiments. (Embodiment 1) FIGS. 1 and 2 are sectional views of a connection structure according to an embodiment of the present invention. This connection structure has three hoses 1
And a pipe member 2 inserted into the hose 1 and branched in three directions, and a resin covering portion 3 covering the entire circumference of the connecting portion between the hose 1 and the pipe member 2.

As the hose 1, a three-layer structure reinforcing hose in which a reinforcing yarn is braided in an intermediate layer is used. The pipe member 2 is composed of a tubular portion 20 that extends in three directions and has a plurality of annular projections 21 on its surface for preventing slipping off, and a thick portion 22 formed between the tubular portions 20 on both sides. The annular protrusion 21 is
It has a tapered surface whose diameter gradually increases from the opening side of the tubular portion 20 toward the thick portion 22 side.

The resin coating portion 3 is provided at a position to cover almost the entire pipe member 2, and at each tip end branching in three directions, an annular convex portion 30 protruding to the inner peripheral surface and biting into the hose 1 is respectively provided. Has been formed. Annular protrusion 30
Is provided at a position facing the annular projection 21 of the pipe member 2, as shown in an enlarged manner in FIG. To form this connection structure, first, the three tubular portions 20 extending in the three directions are inserted into the hose 1, respectively. At this time, a part of the end surface of the hose 1 comes into contact with the thick portion 22 to determine the insertion position. Then, the pipe member 2 with the hose 1 inserted therein is placed in the molding die.

At this time, as shown in FIG. 3, a molding cavity 5 formed by the molding die 4, the hose 1 and the pipe member 2.
At the end portion of 1, the ring-shaped seal core 40 compresses the hose 1 toward the pipe member 2, and the elasticity of the hose 1 seals the molding cavity 5. And the seal core 4
A ring-shaped recess 10 having a surface that is tapered in diameter by compression is formed at a position adjacent to the compressed portion 0.

Then, the molten resin is injected into the cavity 5 to form the resin coating portion 3. At this time, the molten resin is also filled inside the concave portion 10 to form the annular convex portion 30. When the molding die 4 and the seal core 40 are removed after the resin-coated portion 3 is cooled and solidified, a part of the hose 1 pressed by the seal core 40 expands in diameter due to its own elastic reaction force, and as a result, the annular convex portion 30 causes the hose to move. It will be in the state of cutting into 1.

In the hose connection structure of this embodiment, the hose 1 is compressed and sandwiched between the annular projection 30 and the annular projection 21, so that the hose 1 is superior in fastening strength and sealing property to the conventional connection structure. ing. (Embodiment 2) The connection structure of the present embodiment is shown in FIG. In this embodiment, a part of the resin-made covering portion 3 is broken into a ring shape, and a first covering portion 31 that covers the thick portion 22 and a tubular shape that is formed in front of the first covering portion 31 with a space therebetween. It has the same configuration as that of the first embodiment except that it is formed of the second covering portion 32 and the annular convex portion 30 is formed at each end portion.

The connection structure of this embodiment is formed by providing another plate-shaped seal core in the middle portion of the cavity 4 in addition to the seal core 40 of the first embodiment.
According to this connection structure, the number of the annular protrusions 30 is larger than that in the first embodiment, so that the hose 1 has a further increased compressive force and a further improved fastening strength. Since the hose 1 is exposed in a ring shape between the first covering portion 31 and the second covering portion 32,
When the design is not preferable, it is advisable to form a coating layer that covers the first coating portion 31, the second coating portion 32, and the entire portion between them. This coating layer can be formed by molding similarly to the formation of the resin coating portion. In this case, it is advisable to form them continuously by two-color molding.

[Brief description of drawings]

FIG. 1 is a sectional view of a hose connection structure according to an embodiment of the present invention.

FIG. 2 is an enlarged sectional view of a main part of FIG.

FIG. 3 is a cross-sectional view illustrating a method of forming a resin coating portion of the connection structure of FIG.

FIG. 4 is a cross-sectional view of a hose connection structure according to a second embodiment of the present invention.

FIG. 5 is a cross-sectional view of a conventional hose connection structure.

[Explanation of symbols]

1: Hose 2: Pipe member
3: Resin coating part 4: Mold 5: Mold cavity 2
0: Cylindrical part 21: Annular protrusion 22: Thick part
30: annular convex portion 31: first covering portion 32: second covering portion
40: Seal core

Claims (1)

[Claims] 1. A hose, a pipe member having a ring-shaped projection for preventing the hose from being inserted into the hose, and a resin formed by molding over the entire circumference of a connecting portion between the hose and the pipe member. A covering part,
In the hose connection structure, the hose connection structure is characterized in that the resin coating portion has an annular convex portion that bites into the hose on the inner peripheral surface of the end portion.