JPH04201325A - Manufacture of molded hose - Google Patents

Abstract

PURPOSE:To obtain a bent molded hose whose rigidity is caused to improve without generating creases on a resin layer of the innermost layer, by a method wherein after coating a material pipe hose with an outer mold material comprised of a lead encasing material, the same is cut into fixed lengths and the same is heated and vulcanized under a bent state into a molding shape. CONSTITUTION:After formation of an inside resin layer 3, intermediate rubber layer 4, reinforced yarn layer or reinforcement wire layers 5a, 5b on an outer circumferential surface of a resin mandrel 2, to which an outside rubber layer 6 is applied and a material pipe hose 1a in a unvulcanized state is molded. After the material pipe hose 1a is coated with an outer mold material comprised of a lead encasing material, the same is cut into fixed lengths, a shape of which is held in a bent state into a molding shape, which are heated and vulcanized. After completion of partial vulcanization like this, an outer mold material is peeled off from a molded hose main body 1 and the resin mandrel 2 is pulled off further, through which the bent molded hose main body 1 where the inside resin layer 3 is free from creases and it is in a fixed shape is manufactured.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for manufacturing a bend-molded hose having a resin layer as the innermost layer, and more specifically, to a method for manufacturing a bend-molded hose having a resin layer as the innermost layer. The present invention relates to a method for manufacturing a molded hose that can produce a well-curved molded hose.

[Prior Art] Conventionally, the structure of a molded hose with a resin layer as the innermost layer used for automobile air conditioning piping, etc. includes an intermediate rubber layer and a reinforcing thread layer on the outer peripheral surface of the resin layer.

It is made of a resin and rubber composite material with successive outer rubber layers.

[Problem to be Solved by the Invention] However, when a hose made of a composite material of resin and rubber with a resin layer as the innermost layer as described above is bent into a predetermined shape in an unvulcanized state during molding, it is difficult to bend the hose. The inner side is compressed and wrinkles occur in the resin layer.

In particular, if there is a gap between the inner diameter of the unvulcanized raw pipe and the outer diameter of the bent mandrel, there is a problem in that wrinkles will occur on the bent inner surface of the resin layer due to contraction of the reinforcing thread layer during vulcanization. .

When there are wrinkles in a part of the resin layer as described above, internal stress concentrates in the wrinkled area, which not only reduces the durability of the molded hose, but also leads to a decline in quality. .

[Purpose of the invention]

This invention was devised by focusing on such conventional problems, and eliminates wrinkles in the innermost resin layer during molding.
The object of the present invention is to provide a method for manufacturing a bent hose with high quality accuracy and improved durability.

[Means for Solving the Problems] In order to achieve the above object, the present invention extrudes an inner resin layer onto a resin mandrel, and on the outer peripheral surface of this resin layer, an intermediate rubber layer, a reinforcing thread layer or a reinforcing wire layer, and an outer surface are formed. Rubber layers are sequentially applied to form an unvulcanized raw hose. After covering this raw hose with an outer mold material made of leaded material, it is cut to a predetermined length and bent into the molded shape. After vulcanization, the outer mold material is peeled off from the molded hose body, and the resin mandrel is pulled out to produce a curved molded hose body with no wrinkles in the inner resin layer and a predetermined shape. The gist of this is to

[Operation of the Invention] The present invention is configured as described above, and extrudes simultaneously or continuously an inner resin layer consisting of a hollow or solid reusable resin mandrel and an inner tube, and extrudes the outer periphery of this resin layer. An intermediate rubber layer of a predetermined thickness is extruded onto the surface. Then, a blade or spiral is placed on the outer peripheral surface of this intermediate rubber layer.

After forming a reinforcing yarn layer or a reinforcing wire layer made of knit, an outer rubber layer is sequentially applied to form an unvulcanized raw tube hose.

This raw hose is coated with an outer mold material made of a leaded material, and then cut into a predetermined length. This is bent into a molded shape and held in shape, and then heated and vulcanized. After vulcanization,
By peeling off the outer mold material from the molded hose body and then pulling out the resin mandrel, the inner resin layer is free of wrinkles.
Moreover, a bent hose body having a predetermined shape is manufactured.

[Embodiments of the invention]

The present invention will be described in detail below based on the accompanying drawings.

FIG. 1 shows a partially cutaway perspective view of a molded hose body 1 embodying the present invention. On the outer peripheral surface of the mandrel 2, an inner resin layer 3, an intermediate rubber layer 4. spiral, blade or two
Reinforcing yarn layer or reinforcing wire layer 5a consisting of 7 layers, etc.
, 5b are sequentially applied, and the outer surface thereof is covered with an outer surface rubber layer 6.

A method for manufacturing such a molded hose body 1 is to simultaneously or simultaneously apply a hollow or solid reusable resin mandrel 2 made of polymethyl pentene resin, etc., and an inner resin layer 3 that will become an inner tube on its outer peripheral surface. Extrude continuously.

Then, an intermediate rubber layer 4 of a predetermined thickness is extruded on the outer peripheral surface of this inner resin layer 3, and further, on the outer peripheral surface of the intermediate rubber layer 4,
blade or spiral.

Reinforcing yarn layer or reinforcing wire layer 5a made of knit a
, 5b are formed, an outer rubber layer 6 is sequentially applied to form an unvulcanized raw hose 1a.

After covering this raw hose 1a with an outer mold material 7 made of a leaded material, it is cut into a predetermined length, and as shown in FIG. This is heated and vulcanized.

After completion of vulcanization, the outer mold material 7 is peeled off from the molded hose body 1 and the resin mandrel 2 is pulled out, so that the inner resin layer 3 is free from wrinkles and is bent into a predetermined shape. It is possible to produce I.

By the method described above, the bent hose main body 1 of a predetermined shape is manufactured, so that the innermost inner resin layer 3 does not wrinkle during molding, and the bending is performed with high quality accuracy and improved durability. It is possible to manufacture molded hoses.

〔Effect of the invention〕

In this invention, as described above, an inner resin layer is extruded onto a resin mandrel, and an intermediate rubber layer, a reinforcing thread layer, or a reinforcing wire layer is formed on the outer peripheral surface of this resin layer.

The outer rubber layer is successively knotted to form an unvulcanized raw hose. After covering this raw hose with an outer mold material made of leaded material, it is cut to a predetermined length and shaped into a molded shape. The hose is heated and vulcanized in the bent state, and after vulcanization, the outer mold material is peeled off from the molded hose body, and the resin mandrel is pulled out to produce the bent hose body in a predetermined shape, so it has the following advantages: It has the following effects.

(a) By extruding the resin mandrel and the inner resin layer simultaneously or successively, it is possible to mold the inner resin layer with high quality accuracy without scratches or contamination with foreign matter.

(b) The resin mandrel is economical because it can be pelletized and reused each time.

(C) Since the resin mandrel and the inner resin layer are bent and formed without any gaps, wrinkles do not occur in the inner resin layer, and problems such as stress concentration can be prevented. Durability and quality accuracy can be significantly improved.

(d) Vulcanization processing is efficient because it can be performed in large quantities at once, and productivity can be improved.

(e) The leaded charter material retains its bent shape;
It has the characteristic of being able to maintain its bent shape even at high temperatures during vulcanization.

The leaded material is economical because it can be melted after stripping each time and used again as a leaded material.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway perspective view of a molded hose body embodying the present invention, and FIG. 2 is an explanatory view showing the manufacturing process of the molded hose. ■...Molded hose body, 2...Resin mandrel, 3
...Inner surface resin layer, 4...Intermediate rubber layer, 5a, 5b.
... Reinforcement yarn layer or reinforcing wire layer, 6 ... External rubber layer, 7 ... Outer mold material made of leaded material. Agent Patent Attorney Nobuo Ogawa −

Claims (1)

[Claims] An inner resin layer is extruded onto a resin mandrel, and an intermediate rubber layer, a reinforcing thread layer or reinforcing wire layer, and an outer rubber layer are sequentially applied to the outer circumferential surface of this resin layer to form an unvulcanized raw hose. After covering a raw hose with an outer mold material made of leaded material, it is cut into a predetermined length, and heated and vulcanized while being bent into a molded shape. After vulcanization, the outer mold material is molded. A method for manufacturing a molded hose, which comprises peeling the hose body from the hose body and further pulling out a resin mandrel to produce a bent hose body in a predetermined shape.