JP4976017B2 - High pressure hose - Google Patents

Description

  The present invention relates to a high-pressure hose, and specifically to a high-pressure hose having a fiber reinforcing layer.

Conventionally, high-pressure hoses have been used in various hydraulic or hydraulic devices. This high-pressure hose is a hose in which a fiber reinforcement layer is provided between the inner tube (inner surface layer) and outer skin (outer surface layer) made of thermoplastic resin or rubber, but it is excellent in water resistance and oil resistance and is easy to mold. Resin and rubber hoses are liable to be deformed by pressure. For this reason, a reinforcing layer formed by knitting fibers according to operating pressure or the like is provided as a single layer or a plurality of layers as necessary.
In addition, as a fiber which comprises this reinforcement layer, conventionally, the metal fiber or the polyester fiber and nylon fiber which are cheap and cost-effective are used (for example, refer patent document 1).

  When a gas is used as the fluid of the high-pressure hose, the fiber reinforced hose is subjected to a prepicking process (step of continuously providing minute holes in the outer surface layer) so that the gas that has permeated through the inner tube can be discharged to the outside. (For example, refer to Patent Document 2) In the case of a steel wire reinforced hose, the metal fiber in the reinforcing layer is rusted due to the intrusion of moisture from the prepicking portion, and there is a concern about the decrease in pressure resistance. I couldn't.

  For this reason, when a gas is used as a fluid for the steel wire reinforcing hose, the gas that has permeated through the inner tube may stay in the outer skin, resulting in a bulge or puncture. Further, in a steel wire reinforced hose whose inner tube / outer material is made of synthetic rubber, an inner tube drop (a phenomenon in which the inner tube is recessed inside) may occur.

As described above, when a gas is transported using a conventional high-pressure hose, the above-mentioned various problems occur, and it cannot be stably used as a high-pressure hose.
JP 2002-089756 A JP 59-40079

An object of the present invention is to solve such problems.
That is, an object of the present invention is to provide a high-pressure hose that can be used stably over a long period of time without causing a decrease in pressure resistance even when a gas is transported.

The above-mentioned subject is achieved by the following present invention. That is, the present invention
<1> A high pressure hose having at least an inner surface layer, a reinforcing layer formed by knitting including metal fibers, and an outer surface layer, and provided with a wicking portion in which a piercing hole is formed in the outer surface layer,
A region including the pricking of the surface, a high pressure hose formed by providing a rubber or Ranaru coating layer formed by applying the rubber.

<2> The high-pressure hose according to <1> or <2>, wherein the rubber is at least one selected from silicone rubber-based materials, natural rubber, SBR, and EPDM.

<3> The high-pressure hose according to <1> or <2>, wherein the rubber is silicone rubber.

< 4 > The high-pressure hose according to any one of <1> to < 3 >, wherein the coating layer has a thickness in the range of 10 to 1000 μm.
<5> The high-pressure hose according to any one of <1> to <4>, wherein the coating layer has a thickness in a range of 100 to 500 μm.

<6> The high-pressure hose according to any one of <1> to <5>, wherein the metal fiber is a hard steel wire or a stainless steel wire.

<7> in the range tensile strength of 200N / mm ² ~3200N / mm ² of the metal fibers, wire diameter is in the range of 0.15mm~1.0mm <1> ~ to any of <6> The high-pressure hose described.

  According to the present invention, it is possible to provide a high-pressure hose that can be used stably over a long period of time without causing a decrease in pressure resistance even when transporting a gas.

Hereinafter, the high-pressure hose of the present invention will be described in detail.
The high-pressure hose of the present invention has at least an inner surface layer, a reinforcing layer formed by knitting including metal fibers, and an outer surface layer, and a high-pressure hose provided with a wicking portion in which a piercing hole is formed in the outer surface layer. And the coating layer which consists of rubber | gum or resin is provided in the area | region containing the said wicking part of the surface, It is characterized by the above-mentioned. The coating layer in the present invention is formed by applying rubber.

That is, in the high-pressure hose of the present invention, in order to avoid the occurrence of the above problem, the deterioration of the reinforcing layer including the metal fiber as described above is assumed even when the prepicking hole is formed on the premise of the prepicking process to the outer surface layer. In addition, the function of releasing the original gas to the outside by the precicking process can be maintained.
Specifically, in the present invention, it has been found that the above-mentioned problem can be solved by providing a coating layer made of rubber or resin having gas permeability in a region including a priking portion on the hose surface.

In the present invention, each of the inner surface layer, the reinforcing layer, and the outer surface layer may be independently a single layer, or each may be composed of a plurality of layers as required or necessary. In addition, the high-pressure hose of the present invention may have two or more of the inner surface layer, the reinforcing layer, and the outer surface layer, and other layers such as a liner layer, an intermediate layer, and a coating layer depending on the purpose. You may have.
Specifically, for example, in addition to the configuration of an inner surface layer-reinforcing layer-outer surface layer, an inner surface layer-reinforcing layer-intermediate layer-outer surface layer or an inner surface layer-reinforcing layer-intermediate layer-reinforcing layer-outer surface layer Can take various forms.

Hereinafter, the high-pressure hose of the present invention will be described along each configuration.
(Inner layer)
The material for the inner surface layer constituting the high-pressure hose of the present invention is not particularly limited, and can be appropriately selected in consideration of the physical and chemical properties of the substance transported in the hose. Among these, an inner surface layer made of a rubber material composition having both airtightness (non-permeability of substances), flexibility (flexibility), durability, and the like is preferably used.

  Examples of the rubber component constituting the rubber material composition include ethylene-propylene copolymer rubber (EPM), ethylene-propylene-diene terpolymer rubber (EPDM), acrylic rubber (ACM), and chloroprene rubber (CR). Chlorosulfonated polyethylene rubber, hydrin rubber, styrene-butadiene copolymer rubber (SBR), acrylonitrile-butadiene copolymer rubber (NBR), isobutylene-isoprene copolymer rubber (IIR), natural rubber (NR), isoprene rubber (IR) ), Butadiene rubber (BR), urethane rubber, silicone rubber, fluorine rubber, and the like. These rubber components can be used alone or as an arbitrary blend of two or more.

  Among the above rubber components, butyl rubber (IIR) is preferable from the viewpoint of airtightness, and acrylic rubber (ACM), chloroprene rubber (CR), chlorosulfonated polyethylene rubber, hydrin rubber, and acrylonitrile-butadiene are used from the viewpoint of oil resistance. Polymer rubber (NBR), silicone rubber, and fluorine rubber are preferable. From the viewpoint of heat resistance, ethylene-propylene copolymer rubber (EPM) and ethylene-propylene-diene terpolymer rubber (EPDM) are preferable, and low temperature. From the viewpoint of flexibility, silicone rubber and butadiene rubber (BR) are preferable.

  Further, as the rubber composition for the inner layer of the hose, in consideration of material strength, durability, extrusion moldability, etc., known rubber compounding chemicals and rubber fillers generally used in the rubber industry are used in the present invention. Can be used as long as the purpose is not impaired. Examples of such compounding chemicals and fillers include inorganic fillers such as carbon black, silica, and calcium carbonate; process oils, plasticizers, softeners; vulcanizing agents such as sulfur; and additives such as zinc oxide and stearic acid. Sulfur aids; vulcanization accelerators such as dibenzothiazyl disulfide; anti-aging agents such as N-cyclohexyl-2-benzothiazyl-sulfenamide, N-oxydiethylene-benzothiazyl-sulfenamide; antioxidants, prevention of ozone degradation An additive such as an agent can be used as appropriate. These compounding chemicals and fillers may be used alone or in combination of two or more.

Moreover, when the inner surface layer does not have to have flexibility, the inner surface layer may be made of a thermoplastic resin. Examples of the thermoplastic resin that can be used here include polyamide, polyester, and polyurethane.
When the thermoplastic resin is used, the inner surface layer may have a single layer structure made of the thermoplastic resin, or may have a laminated structure in which the outer surface is made of a thermoplastic resin. In the case of a laminated structure, it may have an inner layer made of other thermoplastic polyamide, polyester resin or rubber, polybutene resin, cross-linked polyethylene resin, etc. suitable for the application on its inside, and its surface is heated. Can be configured by coating with a plastic resin layer,
Moreover, it is good also as a laminated structure which coated the fluororesin etc. on the inner surface of inner layers, such as rubber | gum.

  Although the thickness of an inner surface layer changes with kinds of material which comprises an inner surface layer, it is the range of 0.1-3 mm, Preferably it is the range of 0.5-2.0 mm. In addition, the inner diameter of the hose is selected according to the purpose, but generally it is preferably in the range of 3 mm to 25 mm.

(Reinforcing layer)
The reinforcement layer formed by knitting including the metal fibers constituting the high-pressure hose of the present invention is not particularly limited in material and structure, and can be appropriately selected according to the purpose and necessity.
In the present invention, the reinforcing layer contains metal fibers, and a braided structure composed of metal fibers alone or a combination of metal fibers and organic fibers is preferable. The effect of the present invention is particularly effective when metal fibers alone are used. The most effective.

  These fibers are preferably knitted (knitted), preferably in a spiral shape or a blade shape, and are arranged on the outer peripheral surface of the inner surface layer. The fiber and knitting method used for this fiber reinforcement layer are not particularly limited, and can be appropriately selected according to the intended use. Further, an adhesive rubber sheet may be inserted between the alternately wound fiber layers.

  The reinforcing layer may be formed of two or more layers. The number of layers is preferably determined appropriately according to the pressure of the liquid during use, that is, the internal pressure applied to the hose. There is no particular limitation on the configuration of the individual layers in the reinforcing layer in this case, but a configuration in which metal wires are wound in a mesh shape (mesh configuration) is preferable. Moreover, it can also be set as the structure (helical structure) etc. by which the metal wire was wound helically. The mesh configuration is mainly used for low pressure applications, and the helical configuration is mainly used for high pressure applications.

  The metal fiber used for the reinforcing layer is not particularly limited, but preferably, a metal wire, for example, a hard steel wire with brass plating; a stainless steel wire; a known metal wire with galvanization; .

  As for the hard wire, the piano wire is defined in JIS G 3502, the hard steel wire is defined in JIS G 3506, and the stainless steel wire for spring is defined in JIS G 4314. In addition, a stainless steel wire that can prevent corrosion in high pressure applications can be used.

The tensile strength of the metal fibers is preferably in the range of ^{200N / mm 2 ~3200N / mm 2} , the range of 2000N / mm ² ~2900N / mm ² is more preferable. The wire diameter is preferably in the range of 0.15 mm to 1.0 mm, and more preferably in the range of 0.2 mm to 0.4 mm. Although it depends on the type of metal fiber, if the tensile strength is less than 200 N / mm ² or the wire diameter is less than 0.15 mm, the rigidity may be low and the force against bending of the hose may be weakened. is there. On the other hand, if the tensile strength exceeds 3200 N / mm ² and the wire diameter exceeds 1.0 mm, the flexibility of the entire hose may be considerably reduced.

  Examples of the organic fiber include aramid fiber, polyester fiber, polyarylate fiber, nylon fiber, vinylon fiber, polyethylene terephthalate fiber, polyethylene naphthalate fiber, ultrahigh molecular weight polyethylene fiber, and carbon-based fiber. The organic fibers used in the present invention preferably have an amount of heat shrinkage of 0.3% or more, preferably 1% or more after heating at 150 ° C. for 30 minutes, compared to before heating. In view of heat shrinkability and durability, polyethylene terephthalate fibers are particularly preferable. Moreover, you may use the blended yarn which combined 2 or more types of fiber mentioned above according to the need and the objective.

  In order to increase the heat shrinkability, the reinforcing fiber may be preliminarily subjected to a heat stretching treatment so as to obtain a desired heat shrinkage rate.

  In addition, at the time of vulcanization after the lamination of the respective layers, in order to improve the adhesion between the inner surface layer and the reinforcing layer, and between the reinforcing layer and the outer surface layer, an adhesive treatment agent or a chemical agent is used in advance for the reinforcing fiber. Also good. Specifically, it is used by dipping in an adhesive treatment agent liquid (for example, an RFL resin dispersion, or an epoxy resin liquid as a first liquid and an RFL resin dispersion as a second liquid) before the above heat stretching treatment. Is preferred.

  Only one type of fiber may be used for the reinforcing layer, or two or more types may be used in combination. The thickness and the number of braids of the reinforcing fibers listed above can be appropriately determined according to the pressure at the time of use, but in consideration of the reinforcing property, flexibility, durability, etc., two layers in the opposite direction It is preferable to wind the above. Here, a presser thread may be provided outside the reinforcing layer as necessary.

  The thickness of the reinforcing fiber used in the present invention is preferably in the range of 560 to 10,000 dtex, and more preferably in the range of 1100 to 5000 dtex.

(Outer surface layer)
In the high-pressure hose of the present invention, an outer surface layer is further provided outside the reinforcing layer. The outer surface layer can be composed of, for example, a layer made of a thermoplastic resin or the like as in the conventional high-pressure hose, or may be composed of the various rubbers. By providing the outer surface layer, the fibers constituting the reinforcing layer are protected, and the reinforcing layer can be prevented from being damaged, and the appearance is also preferable.
The general thickness of the outer surface layer is preferably in the range of 0.3 mm to 2.0 mm.

(Coating layer)
In the high-pressure hose of the present invention, the hose surface laminated in the order of the inner surface layer, the reinforcing layer, and the outer surface layer is subjected to a prepicking process, which will be described later, and then a rubber or resin coating layer is formed on the surface including the priming portion on the surface. Form. The rubber or resin constituting the coating layer is waterproof and rustproof so as not to cause rust on the metal fibers constituting the reinforcing layer by sealing the prickle holes, as described above. In order to release the gas that has permeated through the inner surface layer to the outside, it is preferable that the gas has a certain gas permeability or more.

As the rubber for the coating layer, one or more selected from silicone rubber materials, natural rubber, SBR and EPDM can be used.
In these, it is preferable to use the silicone rubber excellent in the said gas permeability, waterproofness, and rust prevention property.

The resin for the covering layer, Ru can be used stretched also had a port re tetrafluoroethylene (PTFE).

  The covering layer needs to be formed in an area including at least the pre-nicking portion. Here, the above-mentioned “region including the prikking portion” refers to a range that can completely cover the wicking hole on the surface of the hose and is further expanded to the vicinity thereof if necessary. Therefore, depending on the constituent material, it may be a coating layer covering the entire outer surface layer.

  The thickness of the coating layer is preferably in the range of 10 to 1000 μm, and more preferably in the range of 100 to 500 μm. If the thickness is less than 10 μm, moisture from the outside air or the like may not be sufficiently blocked from the reinforcing layer, and if it exceeds 1000 μm, the gas release effect may be insufficient.

Next, the manufacturing method of the high-pressure hose of the present invention will be described together with the precicking process.
The high-pressure hose of the present invention can be manufactured by, for example, (1) a step of extruding and coating the inner surface layer on the outer peripheral surface of the elastic mandrel, and (2) winding the reinforcing layer on the outer peripheral surface of the coated inner surface layer. A step, (3) a step of extruding and coating the outer surface layer on the outer peripheral surface of the wound reinforcing layer, (4) a step of vulcanizing an unvulcanized hose having an inner surface layer, a reinforcing layer and an outer surface layer, (5 It is carried out through a step of pulling out the mandrel from the vulcanized hose, (6) a step of applying a prepicking process to the surface of the outer surface layer, and (7) a step of forming a coating layer.

  In the above production method, as the elastic mandrel used in step (1), for example, a steel cord is put in the core, and a vulcanized rubber, preferably ethylene-propylene-diene terpolymer rubber (EPDM) is provided on the outer periphery thereof. A mandrel provided with a vulcanized rubber made of rubber can be preferably used. The mandrel may be a thermoplastic resin such as polypropylene or polyamide. What is necessary is just to select the outer diameter of this mandrel suitably according to the internal diameter of the hose to manufacture. An inner surface layer is continuously extruded and coated on the outer peripheral surface of such an elastic mandrel. When it is difficult to release the mandrel and the inner layer after vulcanization, it is preferable to apply a release agent such as silicone to the surface of the mandrel.

  In step (2), a reinforcing layer is wound on the outer peripheral surface of the inner rubber layer. The reinforcing layer is formed by knitting metal fibers, for example, hard steel wire, preferably in a spiral shape or a blade shape, and is disposed on the outer peripheral surface of the inner rubber layer. The fiber and knitting method used for the fiber reinforcing layer are not limited, and can be appropriately selected according to the intended use. Moreover, you may insert the rubber sheet for adhesion | attachment between each layer wound by turns.

  When the outer surface of the inner surface layer is composed of a thermoplastic resin, the outer surface of the inner tube containing the thermoplastic resin is softened, and a reinforcing layer is disposed on the softened resin layer, so that the The resin may be re-cured by holding it as it is, and the inner tube and the reinforcing layer may be welded.

  In the step (3), the outer surface layer is coated on the outer peripheral surface of the reinforcing layer wound as described above. The coating of the outer surface layer can be performed by extrusion molding in which a tubular shape is laminated.

  In step (4), an unvulcanized hose having an inner surface layer, a reinforcing layer, and an outer surface layer is heated for a required time to be vulcanized and cured. By this vulcanization, the inner surface layer, the reinforcing layer, and the outer surface layer are completely vulcanized and integrated, and a predetermined shape and required mechanical characteristics as a hose are obtained. The heating is preferably a dry hot air type.

  In the step (5), the mandrel is pulled out from the hose vulcanized as described above by a known method (for example, by applying water pressure), and a high-pressure hose before precicking and forming a coating layer can be obtained.

In the step (6), a precicking process is performed on the surface of the laminated outer surface layer. In the prepicking process, for example, two rollers provided with needles at regular intervals on the circumference in the rotation direction are arranged facing each other with a gap between them, and a hose is inserted between them to rotate the rollers and at regular intervals on the hose surface. This can be done by a method of forming a precricking hole.
The diameter of the precricking hole is preferably in the range of 100 to 1000 μm, and the interval is preferably in the range of 20 to 3000 mm.
In addition, you may perform the said precicking process before vulcanization | cure of the hose laminated | stacked to the said outer surface layer.

In the step (7), a coating layer is formed on the hose surface in the region including the priking portion. As a coating method, for example, a liquefied rubber or resin is applied to the above region, or a rubber or resin sheet is attached to the above region, and further, a rubber or resin is filled into a prickle hole. Can do.
This step may also be performed before vulcanization of the hose laminated to the outer surface layer, and the coating layer may be vulcanized simultaneously with the inner surface layer and the like in the vulcanization step.

  In the present invention, the above steps (1) to (7) may be performed continuously, or each step may be performed alone as appropriate.

  In addition, after said process (3), you may carry out extrusion coating of the heat resistant resin layer etc. on the outer peripheral surface of the unvulcanized hose which provided the outer surface layer, or you may wrap a sheet. By coating or wrapping in this way, a molding effect can be obtained, and the rubber composition or the like of the outer surface layer can be effectively pressurized and heated to be vulcanized well. Here, as the heat resistant resin layer, a polymethylpentene resin is preferable, and resins such as polypropylene and polyethylene can be used depending on applications. The sheet is not particularly limited as long as it has heat resistance, but a polyamide-based fiber can be suitably used.

  Although it does not restrict | limit especially as a use of the high pressure hose of this invention demonstrated above, It is preferable to use as a hose which conveys gas as mentioned above, and it is preferably used especially as a hose for transportation of high pressure hydrogen gas.

  Examples of the present invention will be described below, but the present invention is not limited to these examples.

<Example 1>
(Production of high-pressure hose)
-Inner layer-
An extruded polyamide resin tube having an inner diameter of 7 mm and a wall thickness of 1.0 mm was used.

-Reinforcing layer-
Using the spiral reinforcing layer knitting machine on the outer circumference of the inner surface layer produced above, a diameter of 0.3 mm hard steel wire wire (core wire is iron, copper and galvanized, tensile strength: 2800 N / mm ² ), Six layers were alternately wound in a spiral shape to prepare a reinforcing layer.
Between each reinforcing layer, a hollow fiber layer of polyester fiber was similarly wound in five layers in a spiral shape.

-Outer surface layer-
Next, an outer surface layer was formed on the reinforcing layer by extrusion molding of a polyamide resin.

-Pricking treatment, formation of coating layer-
The surface of the high-pressure hose was subjected to a priming treatment using a priming roller. As a result, prepicking holes having a diameter of about 100 μm were formed on the hose surface in a straight line at about 50 mm intervals in the length direction (pricing part).

  Next, a silicone rubber coating material (Supermed X, manufactured by Cemedine Co., Ltd.) is applied to the hose surface so as to cover the formed priming part, and a protective heat-shrinkable tube is applied to the application part, according to the present invention. A high pressure hose was obtained.

(Evaluation)
Using helium gas, the pressure was set to 10 MPa, and a continuous pressurization test for 1500 hours was performed.
As a result, the helium gas that has permeated through the inner tube does not stay between the reinforcing layer and the jacket, but is released to the outside from the priking part, and phenomena such as peeling, swelling, and destruction of the jacket do not occur. It was.

  Further, the salt spray cycle test described in JIS H 8502 8.1 was conducted for 20 days, but no rust and discoloration of the reinforcing layer due to moisture intrusion from the priking portion did not occur.

<Comparative Example 1>
In the production of the high-pressure hose of Example 1, a high-pressure hose was produced in the same manner except that the precicking treatment was not performed, and the helium gas continuous pressurization test of Example 1 was conducted.
As a result, the inner tube permeating gas stayed between the reinforcing layer and the outer casing, and after about 120 hours, the outer casing peeled from the reinforcing layer.

<Comparative example 2>
In the production of the high-pressure hose of Example 1, the salt spray cycle test of JIS H8502 8.1 was performed using a high-pressure hose that did not form a coating layer after the prepicking treatment.
As a result, discoloration (rust) occurred in the reinforcing layer immediately below the prepicked portion after about 96 hours.

  As is clear from the above results, in the high-pressure hose of Comparative Example 1, the gas that permeated the inner appearance stayed between the reinforcing layer and the outer cover, and the outer cover was swollen and the outer cover was broken. Further, in the high pressure hose of Comparative Example 2, although the effect of releasing the inner tube permeating gas can be obtained, moisture enters from the outside through the prikking portion, and as a result, the reinforcing layer is corroded, and the fixed pressure resistance is reduced when used for a long time. It turns out that it happens. On the other hand, in the high-pressure hose of the example manufactured according to the present invention, it was found that the above problems did not occur and the durability performance was excellent.

Claims (7)

A high-pressure hose having at least an inner surface layer, a reinforcing layer formed by knitting including metal fibers, and an outer surface layer, and provided with a wicking portion in which a piercing hole is formed in the outer surface layer,
Wherein the region including the pricking unit, high pressure hose, characterized by comprising providing a rubber or Ranaru coating layer formed by coating a rubber surface.   The high-pressure hose according to claim 1, wherein the rubber is at least one selected from silicone rubber-based materials, natural rubber, SBR, and EPDM.   The high-pressure hose according to claim 1 or 2, wherein the rubber is silicone rubber. The thickness of the said coating layer is the range of 10-1000 micrometers, The high pressure hose of any one of Claims 1-3 characterized by the above-mentioned.   5. The high-pressure hose according to claim 1, wherein a thickness of the coating layer is in a range of 100 to 500 μm.   The high-pressure hose according to claim 1, wherein the metal fiber is a hard steel wire or a stainless wire. The tensile strength of the metal fiber is in the range of ^{200N / mm 2 ~3200N / mm 2} , any one of claims 1 to 6, wherein the wire diameter is in the range of 0.15mm~1.0mm The high pressure hose according to item.