JPH0596629A - Method of manufacturing hose with connection - Google Patents

Abstract

(57) [Summary] [Purpose] A manufacturing method of inserting a pipe end into a hose, arranging the end in a hose as an insert, and forming a resin-coated portion integrally covering a joint between the hose and the pipe. In, the sealability is satisfied, and the movement of the insert is prevented without the hose being caught. [Structure] In a molding process, a seal ring 4 for holding the hose 2 in a reduced diameter at a position corresponding to an end of a resin coating portion is held on the entire surface of a molding die 3 to prevent a molding material from leaking. It is characterized in that the hose 2 is firmly held by a chuck member 5 that is held adjacent to the seal ring 4 by the molding die 3 and locally presses the hose 2 in the circumferential direction in the inner diameter direction. ..

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a hose having a connecting portion formed by integrally connecting a pipe and a hose with a resin coating portion. INDUSTRIAL APPLICATION This invention can be utilized for manufacture of the branch hose, such as a radiator hose of a motor vehicle.

[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. 9, 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. After that, a branch pipe (hereinafter referred to as an insert) to which a hose is attached is placed in a mold as shown in FIG. 10, and the hose surface is pressed by seal rings 401, 402, 403 at the end of each branch cylinder to seal. And fix it. Then, the mold surface of the mold 400, the seal rings 401 to 403, and the cavity 500 formed by the insert are filled with molten resin by injection molding, and the resin coating portion 300 is formed on the joint portion and the central portion of the branch pipe 100.
At this time, the resin coating portion 300 contracts and solidifies at a contraction rate of 0.5% or more, so that a pressure reducing force acts on each hose together with the injection pressure. As a result, the respective hoses 201 to 203 are strongly sandwiched between the resin coating portion 300 and the branch pipe 100, and a high sealing pressure is obtained.

[0004]

However, in the conventional manufacturing method described above, since the hose, which is an elastic body, is sandwiched and held by the seal ring, the insert in the mold is made by injection pressure during injection molding. Was slightly moved (about 0.8 mm). When the insert moves in this manner, there arises a problem that the formed resin coating portion has an uneven thickness or burrs occur. In order to solve such a problem, it is necessary to strengthen the holding force of the insert in the mold.

Therefore, it can be considered to increase the holding force of the insert by the seal ring. As shown in FIGS. 2 and 3, this seal ring has a two-divided shape, and is configured to clamp and seal the hose by the mold clamping force.
Therefore, if the inner diameter of the seal ring is made significantly smaller than the outer diameter of the hose attached to the branch tube, the hose can be firmly held, but on the other hand, the split part of the seal ring causes biting of the hose and May cause scratches.

On the other hand, Japanese Patent Laid-Open No. 60-241595 discloses a method of providing a tab projecting from the surface of a branch pipe and holding the tab in contact with the mold surface. According to this method, the movement of the insert can be surely prevented, but it is difficult to cover the end face of the tab with the resin coating portion, and there is concern about the sealing property. The present invention has been made in view of such circumstances, and an object thereof is to satisfy the sealing property and prevent the movement of the insert without the hose being caught.

[0007]

A method of manufacturing a hose having a connecting portion according to the present invention, which solves the above-mentioned problems, includes a connecting step of inserting an end portion of a pipe into the hose and connecting the hose to each other, and a connecting step of the hose. In the molding process, the molded pipe is placed in a molding die to form a resin coating part that integrally coats the joint part of the hose and the pipe, and A seal ring that holds the hose around the entire circumference at a position corresponding to the end of the coating is held on the mold surface to prevent the molding material from leaking, and the hose is held by the mold adjacent to the seal ring. The hose is firmly held by a chuck member that locally presses in the inner diameter direction in the circumferential direction.

The feature of the present invention resides in that the hose is held by the chuck member while sealing with the seal ring in the molding process. Therefore, since it is not necessary to firmly hold the hose with the seal ring, the hose is prevented from being caught. Further, since the chuck member does not need to have a sealing property, the hose can be locally pressed and held in the circumferential direction, and the hose is not caught by the chuck member.

In order to locally press and hold the hose with the chuck member in the circumferential direction in the inner diameter direction, for example, a chuck ring having a two-divided structure may be used, and a polygonal recess for holding the hose may be formed in each chuck ring. In this way, the portion corresponding to the side of the polygon comes into tangential contact with the hose and can be pressed locally. Further, since the extra thickness portion moved by pressing enters the portion corresponding to the corner, the hose is prevented from being caught. However, it is desirable to avoid that the portions corresponding to the sides of the polygon are located on the dividing surface of the chuck ring, and to arrange the corner portions on the dividing surface. This surely prevents the hose from being caught. The recesses may be provided symmetrically to the chuck ring having a divided structure.
It is also preferable that the center is displaced rearward with respect to the direction in which the injection pressure acts. By doing so, the movement of the insert can be further prevented. Further, it is desirable that the surfaces of the chuck member and the seal ring that come into contact with the hose be chamfered.

The bonding step and the molding step can be performed in the same manner as in the conventional method except that a chuck member is used. Further, the materials of the pipe, the hose, and the resin coating portion can be selected from various materials and used as in the conventional case.

[0011]

In the method of manufacturing a hose having a connecting portion according to the present invention, the sealing property is provided by the seal ring and the chuck member is held so as to withstand the injection pressure. That is, the seal ring may press the hose with a force sufficient to prevent the molten resin from leaking when the resin coating portion is molded. Therefore, it is not necessary to strongly hold the hose with the seal ring, and the hose is prevented from being caught.

On the other hand, since the chuck member does not need to contribute to the sealing property, the hose is locally pressed in the circumferential direction toward the inner diameter side. Therefore, the surplus portion moved by pressing can escape to the space other than the local pressing portion and can be pressed with a strong force without being caught, so that the insert can be firmly held. Therefore, according to the manufacturing method of the present invention, the sealability is satisfied, and the movement of the insert can be reliably prevented without the biting of the hose. As a result, the resin coating portion has a uniform thickness, and burrs can be prevented from occurring.

[0013]

EXAMPLES The present invention will be specifically described below with reference to examples. (Embodiment 1) FIG. 1 shows a molding die used in this embodiment together with an insert. The insert 10 is a branch pipe 1 made of glass fiber reinforced polyamide and branched in three directions.
And three hoses 2 into which the respective branch cylinders 11 of the branch pipe 1 are inserted in the joining step. The branch pipe 1 has a thick central portion 12 from which a branch cylinder 11 branches in three directions. <Joining Step> In the joining step, the hose 2 is inserted into each branch cylinder 11. Here, since the outer diameter of the branch cylinder 11 is formed larger than the inner diameter of the hose 2, the hose 2 is inserted into the surface of the branch cylinder 11 in the expanded state, and the central portion 12
Axial positioning is performed by abutting on the end surface of the.
Further, on the three end faces of the central portion 12, the positioning groove 13 is provided.
Are formed respectively, and by aligning a mark (not shown) formed on the hose 2 with the groove 13, the branch cylinder 11 is positioned in the circumferential direction. A plurality of ring-shaped projecting ridges 14 are formed on the outer peripheral surface of the branch cylinder 11 so as to make one round in the circumferential direction, and function as a retainer for the hose 2. <Molding Step> The insert 10 formed as described above is placed in the molding die 3. Here, the molding die 3 is composed of an upper die and a lower die, and the lower die is shown in FIG. The molding die 3 holds a seal ring 4 and a chuck ring 5 adjacent to the outside of the seal ring 4 at a position where the end of the branch cylinder 11 is arranged.

Here, the seal ring 4 is divided symmetrically at the center as shown in FIGS. 2 and 3, and both are combined to form a ring shape. The center hole formed by combining the two forms a two-step circular shape having a large diameter portion 40 and a small diameter portion 41, and the inner diameter of the small diameter portion 41 of the hose 2 inserted into the branch cylinder 11 of the insert 10. It has the same outer diameter. Further, notches 42 are formed on the side surfaces of the seal ring 4, respectively.

The chuck ring 5 is divided symmetrically at the center as shown in FIGS. 4 and 5, and is constructed so that both are combined to form a ring. The central hole 50 formed by combining the two has a rhombic shape, and its corners are located on the division surface. This central hole 50
The diameter of the inscribed circle is 5% smaller than the outer diameter of the hose 2 inserted into the branch cylinder 11 of the insert 10. The inner peripheral surface of the center hole 50 is chamfered. A notch 51 is formed on each side surface of the chuck ring 5. The notch portion 51 is located at the same position as the notch portion 42 of the seal ring 4, and engages with a part of the upper die and the lower die so that the seal ring 4 and the chuck ring 5 are held by the molding die 3, respectively. Is configured.

The seal ring 4 is arranged around the hose 2 whose diameter is expanded at the tip of the branch cylinder 11, and the inner peripheral surface of the small diameter part 41 is liquid-tightly contacted with the hose 2 for sealing. Since the inner diameter of the small diameter portion 41 is the same as the outer diameter of the enlarged diameter portion of the hose 2, there is no problem that the hose 2 is caught between the divided surfaces of the seal ring 4, and the hose 2 is not damaged. It is prevented. The large diameter portion 40 faces the central portion 12 side and is continuous with the mold surface of the molding die 3 to form a part of the mold surface.

The chuck ring 5 is arranged in contact with the outer side of the seal ring 4 in the axial direction, and the center hole 50 is formed by the clamping force.
A hose 2 having a diameter increased by being inserted into a branch cylinder 11 is sandwiched therein. Since the diameter of the inscribed circle of the center hole 50 is smaller than the outer diameter of the expanded hose 2, the four side portions 52 of the center hole 50 press the hose 2 and firmly hold it, as shown in FIG. To do. Since the extra thickness portion moved by this pressing enters the four corner portions 53, the hose 2 is prevented from being caught between the divided surfaces. As a result, the insert 10 is held and fixed in the molding die 3. At this time, the mold surface 3 of the molding die 3
0, the end portion of the hose 2, the central portion 12 of the branch pipe 1, and the large diameter portion 40 of the seal ring 4 form a cavity 31 in a space.

Molten resin is injected from the gate 32 into the cavity 31. At this time, the injection pressure is the insert 1
However, since the chuck ring 5 firmly holds the insert 10, the movement of the insert 10 is prevented. Therefore, the seal ring 4 and the insert 1
There is no relative movement between 0 and. As a result, the seal ring 4 closely seals with the hose 2 to prevent burrs from occurring. In addition, the obtained resin coating portion has a uniform thickness as a whole.

The molten resin injected into the cavity 31 strongly presses the hose 2 due to the injection pressure and the contraction caused by cooling, and comes into pressure contact with the branch cylinder 11. Therefore, it is possible to easily manufacture a branch hose in which the resin-coated portion has a uniform thickness, has no burr, and the hose 2 is strongly fastened to the branch pipe 1. In addition,
In the present embodiment, the central hole 50 of the chuck ring 5 has a rhombic shape, but it may have a polygonal shape such as a hexagonal shape as shown in FIG. 7. However, as with the diamond shape, if the sides are located on the dividing surface, biting may occur, so
It is necessary to configure the dividing surface so that the corners are located. (Example 2) This example is the same as Example 1 except that the shape of the chuck ring 5 is different. That is, as shown in FIG. 8, in the present embodiment, the center of the center hole 50 is the hose 2.
It is formed so as to deviate from the axis center of about 0.5 mm (Fig. 8).
Is drawn exaggerated in). Therefore, when the hose 2 is placed on the molding die 3, the pressing force of the hose 2 is different on the four sides, and the insert 10 is in a state of being moved before injection. If the direction of this movement is adjusted to be opposite to the direction of movement at the time of injection, the amount of movement of the insert 10 can be made even smaller than in the first embodiment.

[Brief description of drawings]

FIG. 1 is an explanatory cross-sectional view showing a state in which an insert is placed in a molding die in one embodiment of the present invention.

FIG. 2 is a plan view of a seal ring used in an example.

3 is a cross-sectional view taken along the line AA of FIG.

FIG. 4 is a plan view of a chuck ring used in an embodiment of the present invention.

5 is a sectional view taken along line BB of FIG.

FIG. 6 is an explanatory view showing a state in which a chuck ring holds a hose.

FIG. 7 is a plan view showing another aspect of the chuck ring.

FIG. 8 is a plan view of a chuck ring used in Example 2.

FIG. 9 is a sectional view of a conventional branch hose.

FIG. 10 is an explanatory cross-sectional view of a conventional manufacturing method.

[Explanation of symbols]

1: Branch pipe 2: Hose
3: Mold 4: Seal ring 5: Chuck ring (chuck member)

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location F16L 41/08 8508-3J // B29L 31:24 4F

Claims (1)

[Claims] 1. A joining step of inserting an end of a pipe into a hose to join the hose and the pipe, and a step of placing the pipe to which the hose is joined in a molding die to join the hose and the pipe. In a molding step of forming a resin coating part that integrally coats the hose, and in a method of manufacturing a hose having a connecting part, in the molding step, the hose is completely covered at a position corresponding to an end of the resin coating part. A sealing ring held around the circumference is held on the surface of the mold to prevent the molding material from leaking, and the hose is held adjacent to the seal ring in the mold and the hose is circumferentially localized in the inner diameter direction. A method of manufacturing a hose having a connecting portion, characterized in that the hose is firmly held by a chuck member that presses against the hose.