JPH04201323A - 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 a material pipe hose is vulcanized partly, into which a bent mandrel is inserted and main vulcanization is performed. CONSTITUTION:An inside resin layer 3, intermediate rubber layer 4, reinforcement yarn layer or reinforcement wire layers 5a, 5b are applied in order on an outer circumferential surface of a resin mandrel 2, to which an outside rubber layer 6 is applied after that and a material pipe hose 1a in a unvulcanized state is molded. After the material hose 1a is encased with lead, lapped and coated with polymethyl.pentene resin 7, the same is vulcanized partly. After completion of the partial vulcanization, the lead or the resin 7 is peeled off, the resin mandrel 2 is pulled out from the partly vulcanized hose 1b and the partly vulcanized hose 1b is cut into a fixed length. After that, preshaped bent mandrel 8 is inserted into the partly vulcanized hose 1b and the partly vulcanized hose 1b is vulcanized extensively. After completion of extensive vulcanization, the bent mandrel 8 is pulled out from a molded hose main body 1 and the bent molded hose is molded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for manufacturing a molded hose, and more specifically, when manufacturing a bend-molded hose of a resin-rubber composite hose having a resin layer as the innermost layer, The present invention relates to a method for manufacturing a molded hose that is molded without causing wrinkles on the inner surface of a resin layer.

[Conventional technology]

Traditionally, hoses used for automobile air conditioning piping, etc.
A molded hose with a resin layer as the innermost layer is known, and this molded hose is made of resin and rubber, which is made by sequentially applying an intermediate rubber layer, a reinforcing thread layer, and an outer rubber layer to the outer peripheral surface of the innermost resin layer. The hose has an inner diameter of about 4 mm to 25 mm, is a straight pipe type, and is bent in one direction with a bend radius of 300 mm or more during manufacturing.

[Problem that the invention seeks to solve]

However, when the above-mentioned molded hose is in an unvulcanized state, the innermost resin layer is bent with a radius of 200 W or less, especially 15
When molded and vulcanized after being bent to less than 0 aa, wrinkles occur on the inner surface of the bent resin layer, and there is a problem in that the straight hose cannot be bent to the minimum bending radius.

When such wrinkles are present in a part of the resin layer, internal stress is concentrated in that part, which not only reduces the durability of the molded hose but also leads to a reduction in quality.

In addition, there is a problem in that wrinkles occur on the inner surface of the resin layer as described above, and at the same time, a wavy uneven pattern of the reinforcing thread layer or the like occurs on the outer surface of the molded hose, deteriorating the appearance.

Further, there were problems in that the adhesion between the resin layer and the intermediate rubber layer between the eyebrows was reduced, the dimensions were large, and the mandrel insertion processability was poor.

[Object of the Invention] This invention was devised by paying attention to such conventional problems, and it is possible to prevent wrinkles from forming 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 to solve the problem]

In order to achieve the above object, the present invention extrudes an inner resin layer onto a resin mandrel, and sequentially applies an intermediate rubber layer, a reinforcing thread layer, a reinforcing wire layer, and an outer rubber layer to the outer circumferential surface of the unvulcanized raw tube hose. After coating this raw hose with lead or resin, it is partially vulcanized, and after the partial vulcanization is completed, the lead or resin is peeled off and the resin mandrel is extracted from the partially vulcanized hose. After cutting to the specified length,
A pre-shaped bent mandrel is inserted into a partially vulcanized hose, and after the partially vulcanized hose is fully cured, the bent mandrel is pulled out from the vulcanized formed hose body to form a bent hose. Vulcanization degree of sulfur from 2.5%
The gist is that it is set to 95χ.

[Action of the invention]

This invention is constructed as described above, and by partially vulcanizing an unvulcanized raw pipe hose before main vulcanization, the intermediate rubber layer, reinforcing thread layer, and outer rubber layer are slightly hardened. As a result, when the bending mandrel is inserted into the partially vulcanized hose and bent into a predetermined shape,
This suppresses kinks in the inner resin layer and allows molding and vulcanization to be performed without causing wrinkles in the innermost resin layer.

[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 showing a first embodiment of the present invention.
is a flexible resin mandrel 2 with a predetermined diameter made of polymethyl pentene resin, etc.
Inner surface resin layer 3, intermediate rubber layer 4. It is constructed by sequentially applying spirally knitted reinforcing thread layers or reinforcing wire layers 5a and 5b, and covering the outer surface with an outer rubber layer 6.

The thickness of the inner surface resin layer 3 is 0.05ffIln to 2I
IIm, preferably 0.1 mm to 1 mm, is used. The material for the inner resin layer 3 is nylon 6°, nylon 11. Or a blend of these nylons and polyolefins, nylon 6, nylon 66, nylon 11.
Nylon 12 alone or blended with a rubber elastomer, polyester, polyurethane, polysulfone, polyolefin alone or blended with a rubber elastomer, etc. are used.

Further, as the material of the intermediate rubber layer 4, for example, IIR, C
IIR, CR, C3M, NBR, CR, EPDM, acrylic, etc. are used, and the outer rubber layer 6 is made of, for example, 11R, CIIR, CM, CSM, NBR, CR, EP.
DM, SBR, etc. are used.

The reinforcing threads such as polyester, vinylon, rayon, aramid, etc. constituting the reinforcing thread layers 5a and 5b have a dry heat shrinkage rate of 0 to 2.0x, preferably 0 to 1.5% or less at 150°C for 230 minutes. or wire.

In addition, in the case of the embodiment shown in FIG. 2, wire is used as the reinforcing layer 5c and braided, and the other structure is exactly the same as that of the first embodiment. Reference numerals are given and explanations are omitted. The reinforcing yarn layer 5
Yarns a and 5b can also be braided and used in the same manner as above.

A method for manufacturing such a molded hose body 1 is to mold the outer peripheral surface of a hollow or solid reusable resin mandrel 2 using polymethyl pentene resin (manufactured by Mitsui Petrochemical Industries ■...trade name, TPX) or the like. , inner surface resin layer 3 that becomes the inner tube
Push out 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,
A spirally knitted reinforcing yarn layer or reinforcing wire layer 5a, 5b as shown in FIG. 1 or a braided reinforcing layer or reinforcing wire layer 5C as shown in FIG. are sequentially applied to form an unvulcanized raw pipe hose 1a.

As shown in FIG. 3, this raw hose 1a is leaded, wrapped, and coated with polymethyl-pentene resin 7, and then partially vulcanized (referred to as semi-vulcanization or primary vulcanization). The heating temperature for this partial vulcanization is preferably set to a degree of vulcanization of 2.5% to 95χ when converted to an equivalent vulcanization value.

Equivalent vulcanization here refers to the theoretical relationship between vulcanization and temperature. It causes a vulcanization reaction depending on the history.

After the above-mentioned partial vulcanization is completed, the lead or resin 7 is peeled off and the resin mandrel 2 is extracted from the partially vulcanized hose 1b,
After cutting the partially vulcanized hose 1b to a predetermined length, a pre-shaped bent mandrel 8 is inserted into the partially vulcanized hose 1b, and the partially vulcanized hose 1b is fully vulcanized.

After the main vulcanization is completed, the bending mandrel 8 is pulled out from the vulcanized formed hose body 1 to form a bent hose as shown in FIG. 5.

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.

Next, as a result of experimentally molding a curved hose having the inner resin layer 3 as the innermost layer using the manufacturing method described above,
I was able to obtain the results in the table below.

(Left below) Aramid: Aromatic polyamide fiber As is clear from the above experimental results, the degree of vulcanization is 2.5%.
In the range of ~95χ, wrinkles do not occur in the inner resin layer 3,
A smooth curved hose without wrinkles could be obtained.

[Effects of the Invention] The present invention extrudes an inner resin layer onto a resin mandrel as described above, and an intermediate rubber layer is formed on the outer peripheral surface of the resin mandrel.

A reinforcing yarn layer or a reinforcing wire layer and an outer rubber layer are sequentially formed to form an unvulcanized raw hose, and after coating this raw hose with lead or resin, it is partially vulcanized, and the partial vulcanization is completed. After the resin mandrel is removed from the partially vulcanized hose by peeling off the resin and cutting the partially vulcanized hose to a predetermined length, a pre-shaped bent mandrel is inserted into the partially vulcanized hose. After fully curing the partially vulcanized hose,
Since the bent mandrel is pulled out from the vulcanized formed hose body to form the bent hose, the following excellent effects are achieved.

(a) By partially vulcanizing an unvulcanized raw hose before main vulcanization, the intermediate rubber layer, reinforcing thread layer, and outer rubber layer are slightly hardened and have elasticity. As a result, when the bending mandrel is inserted into a partially vulcanized hose and bent into a predetermined shape and molded, kinking of the inner resin layer is suppressed, and wrinkles are not generated in the innermost resin layer. Can be molded and vulcanized.

(b) Since wrinkles are not generated in the inner resin layer, problems such as stress concentration can be prevented, so it is possible to form a curved hose with high quality accuracy and improved durability.

(C) By performing one part vulcanization, the outer surface is closely attached to the glabella.

The dimensions can be on the same level as a conventional hose with an inner resin layer.

(d) 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 and accuracy without scratches or contamination with foreign matter.

(e) The resin mandrel is economical because it can be reused repeatedly.

The vulcanization process is efficient because it can be performed in large quantities at one time, and productivity can be improved.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway perspective view of a molded hose body showing a first embodiment of the present invention, and FIG. 2 is a partially cutaway perspective view of a molded hose body showing a second embodiment of the invention. Figure 3~
FIG. 5 is an explanatory diagram showing the manufacturing process of the molded hose. 1... Molded hose body, 2... Resin mandrel, 3
...Inner surface resin layer, 4...Intermediate rubber layer, 5a, 5b. 5c... Reinforcing yarn layer or reinforcing wire layer, 6... External rubber layer, 7... Leaded material, resin material, 8... Bent mandrel. Agent Patent Attorney Nobuo Ogawa −

Claims (1)

[Claims] 1. A resin layer is provided as the innermost layer, and an intermediate rubber layer is provided on the outer peripheral surface of the resin layer.
In a method for manufacturing a molded hose in which a reinforcing thread layer and an outer rubber layer are sequentially laminated and integrally molded, 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 the inner resin layer. , an unvulcanized raw hose is formed by successively applying outer rubber layers, this raw hose is coated with lead or resin, and then partially vulcanized, and after the partial vulcanization is completed, the lead or resin is peeled off. After removing the resin mandrel from the partially vulcanized hose and cutting the partially vulcanized hose to a predetermined length, a pre-shaped bent mandrel was inserted into the partially vulcanized hose, and the partially vulcanized hose was fully vulcanized. A method for manufacturing a molded hose, which comprises: then pulling out the bent mandrel from the vulcanized molded hose body to form a bent hose. 2. The method for manufacturing a molded hose according to claim 1, wherein the degree of vulcanization in the partial vulcanization is set at 2.5% to 95%.