KR920000783Y1 - Flexible composite hose - Google Patents

Abstract

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Description

Flexible Composite Hose

1 is a longitudinal sectional view of the flexible composite hose of the present invention.

2 is a longitudinal cross-sectional view taken along line A-A of FIG. 1 as an embodiment of the present invention.

3 is a cross-sectional view similar to FIG. 2 as another embodiment of the present invention.

4 is a longitudinal sectional view similar to FIG. 2 as an example of a conventional flexible composite hose.

* Explanation of symbols for the main parts of the drawings

1: inner tube 2: outer tube

3: adhesive

The present invention relates to an improvement on the structure of a flexible composite hose made of a synthetic resin having a relatively small diameter of about 20 mm or less. Such flexible composite hoses have good oil resistance, chemical resistance, and pressure resistance, and in particular, have characteristics of insulating moisture from the liquid flowing into the pipe and insulated from various materials in contact with the outside of the pipe. Due to these characteristics, the flexible composite hose of the present invention intends to provide a supply line for lubrication, air supply, and chemical liquid to various machines and equipment including automobiles.

The conventional flexible composite hose to which the present invention belongs has a structure as shown in FIG.

Such a conventional structure comprises a relatively thin inner tube 11 and a outer peripheral surface of the inner tube 11 made of polyamide resin (nylon) or a fluorine resin (polytetrafluoroethylene known as Te flon). 11 ') an adhesive tape 13 wound spirally around the fabric, a braid reinforcement 14 in the form of a fabric or a mesh covering the adhesive tape 13, and an outer tube formed by injection of a molten synthetic resin ( 12).

Conventional flexible composite hoses for the structures described above have the following drawbacks. That is, the work of winding the adhesive tape 13, the work of covering with the stiffening reinforcing member 14, and the work of forming the outer tube 12 by injection require a large-molecule device and complicated operation accordingly. This leads to high manufacturing costs.

It is an object of the present invention to provide a flexible composite hose which can be manufactured very easily at low cost without loss of oil resistance, chemical resistance and pressure resistance in order to solve the above-mentioned conventional problems.

In order to solve the above-mentioned drawbacks, the inventors have found that, by conducting various studies, the above-mentioned object can be achieved as a hose made of an inner tube and an outer tube of heat shrinkable material. In other words, the present invention provides a composite hose made of synthetic resin so that the inner tube of the synthetic resin is covered with the outer tube of the heat shrinkable material and compressed by the thermal contraction force of the outer tube.

Hereinafter, with reference to the accompanying drawings will be described in more detail the present invention.

According to the present invention, the inner tube is composed of a synthetic resin having flexibility and high oil resistance, chemical resistance and pressure resistance. For example, this includes polyamide resins and fluorosynthetic resins. Examples of the former include nylon-11 (i.e., hydrolyzable acid), nylon-12 (i.e., "diamide" and "grylamide"), and nylon-6 (ie, "amylo"), the latter Examples are commercially available polytetrafluoroethylene (i.e., "Telflon TFE®), tetrafluoroethylene-hexafluoro ethylene" (i.e. "Telflon TFE"), tetrafluoro ethylene-hexafluoro ethylene copolymerizable resins (ie, "Neoflon FEP®) And tetrafluoroethylene-perfluoro alkoxy ethylene copolymerizable resin (ie, “Teflon PFA”), wherein the inner tube may have a relatively thin film thickness and a desired length.

The outer tube consists of heat shrinkable synthetic resin. The outer tube contracts radially at a ratio of 1.3: 1 to 1: 4 when heated, and also contracts or expands from 5% to 10% in the longitudinal direction. In the case of inner tube, it should be made of material having flexibility and high oil resistance, chemical resistance and pressure resistance. Examples of such materials include bridged polyolefins, fluorine synthetic resins and synthetic rubbers. Finally, it is desirable to have flexibility, resilience, recovery from deformation, flexural uniformity and wear resistance at the point where the hose is needed.

Bridge-bonded polyolefins are one of those having a three-dimensional network structure of polymer resin molecules. It is marketed under the trade names "Penntube", "Insultite", "Thermofit Tube", and "Sumitube".

Examples of heat-shrinkable fluoropolymers include polytetrafluoroethylene (ie, "Teflon TFE®), tetrafluoro ethylene-hexafluoropropylene copolymer resins, polytetrafluoroethylene with perfluoroalkoxy groups, ethylene-tetrafluoroethylene copolymer resins and polyvinyl Indene fluoride. These heat shrink tubes are commercially available under the trade name "Penntube", for example.

Examples of heat-shrinkable rubbers include chloroprene rubber (ie "Neoprene") and bridged fluororubbers (ie "Viton"). Heat-shrink tubes consisting of these are commercially available under the trade name "Insultite", for example.

The flexible composite hose of the present invention is manufactured in the following steps.

Firstly, an inner tube 1 having a relatively thin film (as shown in FIG. 1) is made from a suitable material selected according to the intended application. The inner tube is then covered with an outer tube having an inner diameter slightly larger than the outer diameter of the inner tube 1. The material for the outer tube is appropriately selected depending on the specified application.

Finally, the tube assembly of the final double film is passed linearly through the electric furnace at a speed of 0.5 to 1 m / min. The electric furnace is heated to a temperature which causes the outer tube 2 to shrink as desired. Heat shrinkage is applied to the inner tube (1).

In another embodiment, the adhesive 3 is inserted between the inner tube 1 and the outer tube 2 as shown in FIG. This adhesive is applied precisely to the outer axis 1 ′ of the inner tube 1 by suitable means. It is also possible to use an outer tube having an inner surface which is previously coated with a molten pallet or hot melt adhesive. Examples of such adhesives include polyamide adhesives and polyvinyl acetate adhesives commonly used in the manufacture of composite hoses of the type to which the present invention belongs.

The flexible composite hose of the present invention has high pressure resistance because the outer tube excites the inward force to the inner tube due to its heat shrinkage rate. Such heat shrinkage can be achieved simply by passing the double membrane hose assembly through a heating oven. Thin film inner tubes can be easily manufactured from polyamide resins or fluorosynthetic resins, and the outer tubes can be coated in several steps by using small scale devices. Such flexible composite hoses have good oil and chemical resistance in contact with the inside and outside. In addition, it can be manufactured to any length and size desired.

The present invention will be described in more detail with respect to the following examples.

Example 1

An inner tube of 10 mm outer diameter made of polytetrafluoroethylene (Telflon®) and a thickness of 0.5 mm and a length of 50 cm has an inner diameter of 12.7 mm of 0.7 mm of bridged polyolefin (＂Insulitite VFP-876＂), 0.7 The outer tube with a thickness of mm and a length of 50 cm is covered. The straight tube assembly is passed through an electric furnace at a speed of 1 m / min, resulting in thermal shrinkage at 120 to 140 ° C. Thus, a composite hose as shown in FIGS. 1 and 2 is obtained. Such a composite hose has flexibility, excellent chemical resistance and pressure resistance. This is suitable for alcohol fuel piping.

Example 2

The inner tube with 4.6mm outer diameter, 0.3mm thickness and 50cm length made of polyamide resin (nylon) is 6.4mm inner diameter made of chloroprene rubber, 0.9mm thickness and 50cm length. Covered with an outer tube. The straight tube assembly was passed through an electric furnace at a rate of 0.5 m / min at 140-150 ° C. to produce thermal shrinkage. Thus, a composite hose as shown in FIGS. 1 and 2 was obtained. This composite hose is excellent in flexibility and heat resistance. It is suitable for fuel piping in the engine compartment of automobiles.

Example 3

The inner tube, made of polyamide resin (nylon) and covered with a polyamide adhesive, has an outer diameter of 7.0 mm, a thickness of 0.8 mm and a length of 50 cm. It was coated with a median diameter of 9.5 mm and a thickness of 0.3 mm and a length of 50 cm consisting of polytetrafluoroethylene having. The straight tube assembly was passed through an electric furnace at a rate of 0.5 m / min at 160-170 ° C. to effect heat shrinkage. Thus, a composite hose was obtained in which the adhesive layer was inserted between the inner and outer tubes as shown in FIG. This composite hose has an outer surface with excellent flexibility and chemical resistance. This is a solution of battery (sulfonic acid) under air and vacuum.

Claims (11)

A flexible composite hose comprising an inner tube of a synthetic resin and an outer tube of a heat shrinkable material, wherein the inner tube is compressed by the contracting force of the outer tube. The flexible composite hose according to claim 1, wherein the outer tube is made of a synthetic resin that contracts in a ratio of 1.3: 1 to 4: 1 in the radial direction and shrinks or elongates by 5 to 10% in the longitudinal direction. The flexible composite hose according to claim 1 or 2, wherein the outer tube is made of one member selected from the group consisting of crosslinked polyolefin resin, fluorosynthetic resin and synthetic rubber. The flexible composite hose according to claim 3, wherein the crosslinked polyolefin is a polyolefin generated by irradiating the polyolefin with high energy electron beam to form a three-dimensional network structure through the bridge bonding of the polymer molecules. The method of claim 3, wherein the fluoropolymer is polytetrafluoroethylene, tetrafluoro ethylene-hexafluoropropylene copolymer resin, polytetrafluoroethylene to add a perfluoroalkoxy group on the side chain, and polyvinylidene fluorine. Flexible composite hose characterized in that it is one member selected from the group consisting of a ride. The flexible composite hose according to claim 3, wherein the synthetic rubber is chloroprene rubber or bridged fluororubber. The flexible composite hose according to claim 1, wherein the inner tube is made of polyamide resin or fluorosynthetic resin. 8. The flexible composite hose of claim 7, wherein the polyamide resin is one member selected from the group consisting of nylon-11, nylon-12 and nylon-6. The method of claim 7, wherein the fluoropolymer is one member selected from the group consisting of polytetrafluoroethylene, tetrafluoro ethylene-hexafluoropropylene copolypolymer and tetrafluoroethylene-perfluoroalkoxyethylene copolymer resin. Flexible composite hose, characterized in that. The flexible composite hose according to claim 1, further comprising an adhesive layer inserted between the inner tube and the outer tube. The flexible composite hose of claim 10, wherein the adhesive is a polyamide adhesive or a polyvinyl acetate adhesive.