JPH04250025A - Manufacture of bent formed hose - Google Patents

Abstract

PURPOSE:To from a high-quality, precision-finished and durable molded hose with a resin layer free from creases and offset thickness efficiently by introducing the inner resin layer into a resin mandrel and at the same time, pulling a main hose body from an outer mold, and drawing the resin mandrel from the hose body. CONSTITUTION:When manufacturing a bent molded hose body 1, first a reusable resin mandrel 2 and an inner resin layer 3 which becomes an inner pipe on an outer peripheral surface are extruded simultaneously or continuously. In addition, an intermediate rubber layer 4, a reinforcing thread layer or a reinforcing wire layer 5 and an outer rubber layer 6 are arranged sequentially on the outer peripheral surface of the inner resin layer 3 to form a blank hose 1a. Next an outer mold material 7 consisting of a coating lead material is applied to the blank hose 1a as a coat and is vulcanized partially. After that, the outer mold material 7 is peeled apart and cut to a specified length. Following this procedure, the blank hose 1a is heated, then is inserted into an outer mold of pipe shape formed previously to perform regular vulcanization process. Finally the hose body 1 is extracted from the outer mold 8 and at the same time, the resin mandrel is pulled out of the hose body 1.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a method for manufacturing a curved hose having a resin layer as the innermost layer, and more specifically, to efficiently manufacture a curved hose without wrinkles in the resin layer during molding. The present invention relates to a method of manufacturing a bend-formed hose that can be bent.

0002

[Prior Art] Conventionally, the structure of a molded hose with a resin layer as the innermost layer used for air conditioning piping of automobiles, etc. is such that on the outer peripheral surface of the resin layer, an intermediate rubber layer, a reinforcing thread layer, an outer rubber layer, etc. It is made of a composite material of resin and rubber, which is made by sequentially applying. By the way, conventional methods for manufacturing a bend-molded hose having a resin layer as the innermost layer include, for example, a manufacturing method in which a pre-curved inner mandrel is inserted into an unvulcanized hose, and a manufacturing method in which a split mold is used. A method of manufacturing a bent hose is known.

0003

[Problems to be Solved by the Invention] However, the method using the inner mandrel requires that the hose made of a composite material of resin and rubber, which has a resin layer as the innermost layer, be in an unvulcanized state at the time of molding. Alternatively, if the partially vulcanized (semi-vulcanized) state is inserted into a curved mandrel that has been curved in advance and vulcanization is performed, the curved inner side will be compressed and wrinkles will occur in the resin layer. especially,
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 that wrinkles will occur on the bent inner surface of the resin layer due to shrinkage of the reinforcing thread layer during vulcanization. The wall thickness was not adequate, which caused problems with product accuracy.

[0004] Furthermore, the method of manufacturing a curved hose using a split mold has the problem that wrinkles occur on the bent inner surface of the resin layer as described above, making the wall thickness uneven, and the mold There were problems in that it was difficult to match, the mold seams appeared on the outside of the hose, worsening its appearance, and workability was poor. If there are wrinkles in a part (inside) 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 decrease in quality. was there.

[0005]

[Purpose of the Invention] This invention was devised by focusing on the above-mentioned conventional problems, and it is possible to efficiently mold the innermost resin layer without wrinkles or uneven thickness during molding. The object of the present invention is to provide a method for manufacturing a curved hose that can be molded, has high quality accuracy, and has improved durability.

[0006]

[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. Rubber layers are sequentially applied to form an unvulcanized raw hose, and after coating this raw hose with an outer mold material made of leaded material, partial vulcanization or main vulcanization is performed to remove the outer mold material. After peeling off the hose, it is cut to a predetermined length, heated as necessary, and heated or main vulcanized while inserted into a pre-shaped pipe-shaped outer mold. The gist of this method is to pull out a hose body into which a resin mandrel is inserted from an outer mold, and further pull out the resin mandrel from the hose body to produce a bent hose body having a predetermined shape.

[0007] Furthermore, after the main vulcanization is completed, the resin mandrel is pulled out from the hose body inserted into the outer mold, and the hose body is further pulled out from the outer mold to produce a bent hose body having a predetermined shape. It is something to do.

[0008]

Effect of the Invention The present invention is constructed as described above, and an inner resin layer consisting of a hollow or solid reusable resin mandrel and an inner tube is extruded simultaneously or continuously, and the outer periphery of this resin layer is extruded. An intermediate rubber layer of a predetermined thickness is extruded onto the surface. After forming a reinforcing yarn layer or a reinforcing wire layer made of braid, spiral, or knit on the outer peripheral surface of this intermediate rubber layer, outer rubber layers are sequentially applied to form an unvulcanized raw tube hose.

[0009] After covering this raw hose with an outer mold material made of a leaded material, partial vulcanization is performed, and after peeling off the outer mold material, the hose is cut into a predetermined length, and this hose is cut into a predetermined length. The main vulcanization is performed by inserting it into a pre-shaped pipe-shaped outer mold. After the main vulcanization, the hose body with the resin mandrel inserted is pulled out from the outer mold, and the hose is further inserted into the outer mold. To manufacture a bend-molded hose body having a predetermined shape without uneven thickness without causing wrinkles in the innermost resin layer during molding by pulling out a resin mandrel from the main body.

In addition to the above-mentioned method, after the main vulcanization is completed, the resin mandrel is pulled out from the hose body inserted into the outer mold, and the hose body is further pulled out from the outer mold. Moreover, a bent hose body having a predetermined shape without uneven thickness is manufactured.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows a partially cutaway perspective view of a molded hose body 1 according to the present invention. An inner resin layer 3, an intermediate rubber layer 4, and a reinforcing yarn layer or reinforcing wire layer 5 made of spiral, braided, knitted, etc. are sequentially applied to the outer circumferential surface of 2, and the outer surface thereof is covered with an outer rubber layer 6. It is made up of.

[0012] The method for manufacturing such a molded hose body 1 includes 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 the outer circumferential surface of the mandrel. extrude simultaneously or sequentially. Then, an intermediate rubber layer 4 of a predetermined thickness is extruded onto the outer peripheral surface of this inner resin layer 3, and a reinforcing thread layer or reinforcing wire layer made of braid, spiral, or knit is further applied to the outer peripheral surface of the intermediate rubber layer 4. After forming, 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, partial vulcanization (semi-vulcanization) is performed. After peeling off the outer mold material 7, the resin mandrel 2 is cut into a predetermined length without being pulled out, and the hose is heated as necessary, i.e., the resin mandrel 2 is heated to a degree of softening of about 100%. ℃ for about 5 minutes to make it easy to insert, as shown in Figure 2.
Then, main vulcanization is performed by inserting it into a pipe-shaped outer mold 8 that has been molded in advance as shown in FIG.

[0014] If the raw hose 1a is in an unvulcanized state, main vulcanization is performed, but if it has already been main vulcanized, it is sufficient to perform preheating. After the main vulcanization is completed in this way, the hose body 1 with the resin mandrel 2 inserted therein is pulled out from the outer mold 8 in a hot state, and after the resin mandrel 2 is pulled out from the hose body 1, a washing and cooling process is carried out. Then, both ends of the hose body 1 are cut to produce a bent hose body of a predetermined shape.

In addition to the method described above, after the main vulcanization is completed, the resin mandrel 2 is pulled out from the hose body 1 inserted into the outer mold 8, and the hose body 1 is further pulled out from the outer mold 8 to form a predetermined shape. It is also possible to form a bent hose body 1 of. Note that the other methods are completely the same as in the first embodiment. By manufacturing a bent hose body of a predetermined shape by such a method, the resin mandrel 2
Since the molding is performed without creating a gap between the inner resin layer 3 and the inner resin layer 3, there are no wrinkles in the inner resin layer 3, and there is no uneven thickness, making it possible to efficiently manufacture products with high precision. .

[0016]

[Effects of the Invention] The present invention extrudes an inner resin layer onto a resin mandrel as described above, and on the outer peripheral surface of this resin layer,
An intermediate rubber layer, reinforcing thread layer or reinforcing wire layer, and outer rubber layer are sequentially applied to form an unvulcanized raw hose.
After covering this raw hose with an outer mold material made of leaded material, partial vulcanization or main vulcanization is performed, and after peeling off the outer mold material, the hose is cut to a predetermined length and used as needed. After heating or main vulcanization while inserting this into a pre-shaped pipe-shaped outer mold, the hose body with the resin mandrel inserted is pulled out from the outer mold, and the hose body is further heated. Since the resin mandrel is pulled out from the resin mandrel to produce a bent hose body of a predetermined shape, the following excellent effects are achieved. (a). Since the resin mandrel and the inner resin layer are bent and vulcanized with no gap between them, the inner resin layer does not have wrinkles and can be molded without uneven thickness, thereby reducing stress concentration, etc. Since this problem can also be prevented, the durability and quality accuracy of the hose can be significantly improved. (b). Also, since we do not use split molds like in the past,
Productivity and workability are good, and the appearance of the hose body can also be improved. (c). Vulcanization processing is efficient because a large amount can be produced at one time, and continuous molding is also possible.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway perspective view of a molded hose body embodying the present invention.

FIG. 2 is an explanatory diagram showing a forming process of a bend-formed hose of the present invention.

FIG. 3 is an explanatory diagram showing a forming process of a bend-formed hose of the present invention. FIG.

[Explanation of symbols]

1 Molded hose body,
1a Raw pipe hose 2 Resin mandrel
3 Inner surface resin layer 4 Intermediate rubber layer

Claims (2)

[Claims] [Claim 1] An inner resin layer is extruded onto a resin mandrel, and an intermediate rubber layer and a reinforcing thread layer are formed on the outer peripheral surface of this resin layer.
Alternatively, a reinforcing wire layer and an outer rubber layer are sequentially applied to form an unvulcanized raw hose, and this raw hose is coated with an outer mold material made of leaded material, and then partially or fully vulcanized. After peeling off the outer mold material, the hose is cut to a predetermined length, heated as necessary, and heated or main-filled with the hose inserted into a pre-shaped pipe-shaped outer mold. After vulcanization, the hose body into which the resin mandrel has been inserted is pulled out from the outer mold, and the resin mandrel is further pulled out from the hose body to produce a bent hose body having a predetermined shape. Method. 2. After the main vulcanization is completed, the resin mandrel is pulled out from the hose body inserted into the outer mold, and the hose body is further pulled out from the outer mold to produce a bent hose body having a predetermined shape. The method for manufacturing the bend-formed hose described above.