JP2004286143A - High pressure hose - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high pressure hose which can largely prolong the lifespan by adopting an original way of destruction without changing the structure of a conventional high pressure hose. <P>SOLUTION: The high pressure hose includes two or more reinforcement layers 3 between an inner tube 1 and a casing 2, and an intermediate yarn layer 4 interposed between the reinforcement layers 3. Since the reinforcement layer 3 has a spiral structure of hard wire and the intermediate yarn layer 4 is made of high tension fiber, wear at the time when the intermediate yarn layer 4 is rubbed against the hard wire is effectively eliminated, so that the lifespan can be prolonged largely without changing the structure of the conventional high pressure hose. In addition, the inner tube 1 and the casing 2 are made of, for example, thermoplastic resin. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a high-pressure hose used for hydraulic or hydraulic equipment for water jet, civil engineering, construction equipment, and the like, and more particularly, to a high-pressure hose capable of significantly extending its life.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, high-pressure hoses made of resin have been used in various types of hydraulic or hydraulic equipment and the like. That is, it is a hose in which a reinforcing layer of a hard wire is provided between an inner tube and a jacket made of a thermoplastic resin. The reinforcing layer may have a laminated structure of a plurality of layers depending on the operating pressure or the like. In this case, for example, an intermediate yarn layer is wound between reinforcing layers having a spiral structure.
[0003]
This intermediate yarn layer is used to prevent abrasion between the upper and lower reinforcement layers to prevent breakage of the reinforcement layers when pressure is applied to the high-pressure hose. Fibers and nylon fibers have been used (for example, see Patent Document 1).
[0004]
[Patent Document 1]
JP 2001-56073 A (page 2)
[0005]
[Problems to be solved by the invention]
However, the polyester fibers and nylon fibers used in the conventional intermediate yarn layer are damaged by the rubbing caused by the movement of the upper and lower reinforcement layers, which are caused by repeated pressurization in actual use, and relatively early. The intermediate yarn layer was sometimes broken. Then, when the intermediate yarn layer breaks, the upper and lower reinforcing layers are directly rubbed each other, resulting in breakage of the reinforcing layer and breakage of the hose.
[0006]
Therefore, especially in the case of a hard wire spiral structure of a resin hose, the life of the hose is not due to the tensile fatigue of the reinforcing layer due to repeated pressurization, but depends on the friction between the upper and lower reinforcing layers. In many cases, the life was shortened.
[0007]
Accordingly, the present invention provides a high-pressure hose capable of significantly extending the service life by changing the structure of the conventional high-pressure hose to the original destruction form without changing the structure of the conventional high-pressure hose. It is intended to provide a hose.
[0008]
[Means for Solving the Problems]
The present invention has been made to solve the above problems, and the gist of the present invention is to have two or more reinforcing layers between an inner tube and a jacket, and to provide an intermediate yarn layer between the reinforcing layers. , Wherein the reinforcing layer has a spiral structure of a hard wire, and the intermediate yarn layer comprises a high-tensile fiber. The inner tube and the outer cover are made of, for example, a thermoplastic resin.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
The high-pressure hose of the present invention has two or more reinforcing layers between the inner tube and the jacket. Since the reinforcing layer has a hard wire spiral structure, when pressure is applied to the hose, the spiral winding angle changes so as to approach the static angle. Then, each layer of the reinforcing layer moves separately, and rubbing occurs between the layers.
[0010]
In particular, if the pressure changes frequently, the friction increases, and in the worst case, the hard wire may be broken. Therefore, the intermediate yarn layer is provided to prevent the hard wire wires of the reinforcement layer from directly touching each other, but this time, the reinforcement layer and the intermediate yarn layer are rubbed.
[0011]
Here, the high-pressure hose of the present invention characteristically has an intermediate yarn layer made of high-tensile fibers. High-tensile fibers are sometimes used as a reinforcing layer due to their strength, but their properties that are effective against rubbing with hard wire are not known. The present invention has been made by finding that high-tensile fibers are extremely resistant to abrasion, not as a fiber reinforcing layer, but as an intermediate yarn layer between reinforcing layers of a hard wire.
[0012]
Examples of such high-tension fibers include aramid fibers, polyarylate fibers, ultrahigh molecular weight polyethylene fibers, and carbon fibers. Further, it is preferable that the tensile strength is 20 g / d or more and the thickness is 600d to 4500d.
[0013]
The high-pressure hose of the present invention using a high-tensile fiber (aramid fiber) for the intermediate yarn layer has a greater possibility of breaking the hose itself than a high-pressure hose of the same structure and the same dimensions using a conventional fiber (polyester fiber). Has about four times longer life. In the high-pressure hose of the present invention, only the intermediate yarn layer is made of high-tensile fiber, and the reinforcing layer, the inner tube and the outer jacket can be made the same as the conventional high-pressure hose. Absent.
[0014]
Next, the reinforcing layer has a spiral structure of a hard wire, which effectively prevents the generation of kink and ensures the pressure resistance of the hose when pressurized. That is, even if the hose is bent to a small radius, the portion is not flattened due to the rigidity of the hard metal wire, and the reinforcing layer is formed by the internal pressure at a general hose inner diameter (5 mmφ to 12 mmφ) as a high pressure hose. They do not break.
[0015]
In addition, regarding the hard wire, the piano wire is specified in JIS G 3502, the hard steel wire is specified in JIS G 3506, and the stainless steel wire for spring is specified in JIS G 4314, respectively. Stainless steel hard wires can be used to prevent corrosion in high pressure applications.
[0016]
The tensile strength of the hard line ^wire, preferably ^{1500N / mm 2 ~3200N / mm 2} , the wire diameter is 0.15Mm～0.5Mm is preferred. Although it depends on the type of hard wire, if the tensile strength is less than 1500 N / mm ² or the wire diameter is less than 0.15 mm, the rigidity is reduced and the force against bending of the hose becomes weak. It is.
[0017]
The inner tube is made of, for example, a thermoplastic resin, but may have a single-layer structure or a laminated structure. That is, the inner layer may be composed of a simple substance such as rubber, polybutene resin, crosslinked polyethylene resin, or the like, or may have a laminated structure in which the inner surface of rubber or the like is coated with a fluorine resin or the like. The general thickness of the inner tube of the high-pressure hose is 1.0 mm to 3.0 mm.
[0018]
Further, the jacket can be made of, for example, a thermoplastic resin, similarly to the conventional high-pressure hose. The jacket protects the hard wire constituting the reinforcing layer 3 and prevents trauma, and has a general thickness of 0.5 mm to 3.0 mm.
[0019]
【Example】
Hereinafter, specific examples of preferred embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a partially sectional perspective view showing an example of the high-pressure hose of the present invention. The high-pressure hose of the embodiment shown in FIG. 1 includes, in order from the inside, an inner tube 1, a first reinforcing layer 3A, a first intermediate yarn layer 4A, a second reinforcing layer 3B, a second intermediate yarn layer 4B, and a third reinforcing layer 3C. , A third intermediate yarn layer 4C, a fourth reinforcing layer 3D, and a jacket 2. The inner diameter of the hose is 5 mm, and the thickness of the hose is 3.0 mm.
[0020]
In this embodiment, the inner tube 1 and the outer jacket 2 are made of a thermoplastic resin, specifically, the inner tube 1 is made of polyoxymethylene (POM) and the outer jacket 2 is made of polyamide (PA). 0.0 mm, and the thickness of the jacket 2 is 1.0 mm. The first reinforcing layer 3A, the second reinforcing layer 3B, the third reinforcing layer 3C, and the fourth reinforcing layer 3D have a spiral structure of a hard wire made of a hard steel wire, have a wire diameter of 0.3 mm, and are wound. The pitch is 16-21 mm and the winding angle is 54.7 °. By the reinforcing layers 3A to 3D, no kink is generated even if the bending is performed to a small radius.
[0021]
The intermediate yarn layers between the reinforcing layers, that is, the first intermediate yarn layer 4A, the second intermediate yarn layer 4B, and the third intermediate yarn layer 4C are high tension fibers made of aramid fibers and having a thickness of 1000d, It is spirally wound like the reinforcing layer. Therefore, the first intermediate yarn layer 4A is for the movement between the first reinforcing layer 3A and the second reinforcing layer 3B, and is not for the movement between the second reinforcing layer 3B and the third reinforcing layer 3C. For the movement of the second intermediate yarn layer 4B between the third reinforcing layer 3C and the fourth reinforcing layer 3D, the third intermediate yarn layer 4C is interposed.
[0022]
As described above, since the structure of the high-pressure hose of the present invention is the same as that of the related art, there is no problem in the manufacturing process. Since each of the intermediate yarn layers 4A to 4C is made of aramid fiber, which is a high-tensile fiber, the intermediate yarn layers 4A to 4C are extremely resistant to rubbing with the reinforcing layers 3A to 3D. For this reason, the failure mode of the hose is due to the tensile fatigue of the reinforcing layers 3A to 3D due to the repeated pressurization, and the expected life is obtained.
[0023]
【The invention's effect】
The high-pressure hose according to the present invention is a high-pressure hose having two or more reinforcing layers between an inner tube and a jacket, and having an intermediate yarn layer between the reinforcing layers, wherein the reinforcing layer is a spiral wire of a hard wire. It has a structure, and the middle yarn layer is made of high-tensile fiber, so it is effective against rubbing with hard wire, and greatly increases the service life without changing the structure of the conventional high-pressure hose. be able to.
[Brief description of the drawings]
FIG. 1 is a partially sectional perspective view showing an example of a high-pressure hose of the present invention.
[Explanation of symbols]
1 inner pipe 2 outer jacket 3 reinforcing layer 3A first reinforcing layer 3B second reinforcing layer 3C third reinforcing layer 3D fourth reinforcing layer 4 intermediate yarn layer 4A first intermediate yarn layer 4B 2nd intermediate yarn layer 4C ‥ 3rd intermediate yarn layer

Claims (2)

A high-pressure hose having two or more reinforcing layers (3) between an inner pipe (1) and a jacket (2), and an intermediate yarn layer (4) between the reinforcing layers (3), A high-pressure hose characterized in that the reinforcing layer (3) has a hard wire spiral structure and the intermediate yarn layer (4) is made of high-tensile fiber. The high-pressure hose according to claim 1, wherein the inner tube (1) and the outer cover (2) are made of a thermoplastic resin.

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