JP2005155751A - Flexible hose - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pressure resistant hose for well avoiding troubles including separation for a long period by actualizing an increase in pressure resistance while suppressing an increase in weight. <P>SOLUTION: The flexible hose comprises a cylindrical body 2 consisting of an inside layer 4 having an almost flat inner face 2C formed of EPDM, an outside layer 5 formed of EPDM, and a net portion 6 formed of a number of reinforcing yarns arranged between both layers, and a spiral reinforcing part 3 spirally wound and fixed on the outer face of the body 2. The reinforcing part 3 mainly contains at least one type of hard polypropylene and hard polyethylene compatible with the body 2. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention comprises an inner layer made of EPDM having a substantially flat inner surface, an outer layer made of EPDM, and a net-like portion made of a large number of reinforcing yarns arranged between both layers, and particularly requires pressure resistance. The present invention relates to a pressure-resistant hose used in the case.

In the above-mentioned pressure hose, there is an increasing need for a material having excellent cold impact resistance and heat distortion resistance. Among them, EPDM (Ethylene Propylene Diene Mine Linkage), which is attracting attention as a rubber material that can be reduced in weight, is an abbreviation for ethylene propylene. A pressure-resistant hose using a rubber (also called rubber) has been proposed. For example, a pressure-resistant hose is composed of an inner layer made of EPDM, an outer layer made of EPDM, and reinforcing yarns arranged between these two layers (see, for example, Patent Document 1).
Japanese Patent Laid-Open No. 11-311377

  In Patent Document 1, the thickness of the outer layer and the inner layer is increased in order to increase the pressure resistance. However, as the thickness increases, not only the weight increases but also the flexibility decreases. Invited, it was disadvantageous in terms of handling, and material costs increased accordingly, which was also disadvantageous in terms of cost.

  In view of the above-mentioned situation, the present invention intends to solve the problem that the pressure resistance can be increased while suppressing an increase in weight, and troubles such as peeling can be favorably avoided over a long period of time. It is in providing a pressure-resistant hose that can be used.

In order to solve the above-mentioned problems, the pressure-resistant hose of the present invention comprises an inner layer made of EPDM having a substantially flat inner surface, an outer layer made of EPDM, and a net-like portion made of a large number of reinforcing yarns arranged between these two layers. A cylindrical main body portion and a spiral reinforcing portion that is spirally wound around and fixed to the outer surface of the main body portion, and the reinforcing portion is made of hard polypropylene and hard material compatible with the main body portion It is characterized by comprising at least one kind of polyethylene as a main component.
Moreover, you may comprise the said reinforcement part by mixing talc with the said hard polypropylene or hard polyethylene.
Further, the reinforcing portion may be configured by mixing the hard polypropylene and the hard polyethylene with talc.
Moreover, you may equip the junction part of the said reinforcement part and the said outer layer with the helical reinforcement thread | yarn which follows this reinforcement part.
The cross-sectional shape of the reinforcing portion may be a substantially semicircular shape, and a portion corresponding to the diameter of the reinforcing portion may be fixed to the outer surface of the main body portion.

EPDM, which has a low specific gravity among rubber, is used as the material of the main body constituting the hose, and a reinforcing portion formed of polypropylene or polyethylene having a low specific gravity among the plastic materials or both of them is spirally provided on the outer surface of the main body. By doing so, it is possible to increase the strength of the hose while reducing the weight and suppressing the decrease in flexibility as compared with the case where the thickness of the cylindrical main body is simply increased. And since it is a helical reinforcement part, it can be set as the hose which is easy to bend | curve compared with what provides a ring-shaped protrusion.
In addition, by configuring the reinforcing part fixed to the outer surface of the main body part with polypropylene or polyethylene compatible with the main body part or both of them, it is possible to improve the adhesion performance and make it difficult to peel off both. Can be used satisfactorily.
In addition, since a reinforcing thread is provided between the outer layer and the inner layer, it is as good as it is stretched (it has the advantage of being difficult to stretch), and in terms of durability when used for water pressure. Will also be advantageous.
In addition, when the reinforcing part is composed only of polypropylene, the specific gravity is smaller than polyethylene and the weight can be further reduced, as well as excellent heat resistance and oil resistance, as well as tensile strength, bending strength, and rigidity. This is also advantageous. Further, when the reinforcing portion is made of only polyethylene, the flexibility is not lost even at a low temperature, and there is an advantage of strong impact force. In addition, when the reinforcing part is made of polypropylene and polyethylene (preferably containing a larger amount of polypropylene than polyethylene), it is possible to make the hose excellent in all of weight reduction, rigidity and flexibility. it can.

  Rigidity can be improved by mixing talc with hard polypropylene or hard polyethylene to form a reinforcing part, and a hose that is not easily crushed can be obtained.

  Combining hard polypropylene and hard polyethylene with talc to form a reinforcing part provides excellent heat resistance and oil resistance, is advantageous in terms of tensile strength, bending strength, and rigidity, and does not lose flexibility even at low temperatures. There is a strong advantage in impact force.

  It is possible to prevent the hose from expanding radially outward by providing a spiral reinforcing thread along the reinforcing portion at the joint between the reinforcing portion and the outer layer. Moreover, since the reinforcing yarn is used, the increase in the weight of the hose can be neglected.

  The cross-sectional shape of the reinforcing part is almost semicircular, and by fixing the part corresponding to the diameter of the reinforcing part to the outer surface of the main body part, compared with the case where the circular cross-sectional shape is fixed to the outer surface of the main body part In addition, not only can the bonding area be ensured, but also the amount of protrusion of the reinforcing portion radially outward can be kept small, and the adhesion and accumulation of dust between the reinforcing portions can be suppressed.

1 (a) and 1 (b) show a pressure hose 1 (hereinafter simply referred to as a hose) that is excellent in pressure resistance and oil resistance. In addition to guiding liquids for food such as muddy water and juice, various fluids can be used. You can guide.
The hose 1 includes a main body portion 2 having a flat inner surface 2C so that fluid can be smoothly guided, and a reinforcing portion 3 having a substantially semicircular cross section that is melt bonded to the outer surface of the main body portion 2. It has become. A portion of the outer surface of the main body 2 where the reinforcing portion 3 is not welded, that is, an arc shape in which the outer surface 2A between the reinforcing portions 3 and 3 adjacent in the longitudinal direction of the hose is gently recessed radially inward. However, the hose 1 can be easily bent at that portion, but it can also be implemented with a straight outer surface 2A as shown in FIG. In order to raise, you may make it the circular-arc-shaped outer surface which protruded to the radial direction outer side gently. The hose 1 is a hose that can be used particularly effectively when it is lightweight and requires shape retention and flexibility. 2 is the same as that in FIGS. 1A and 1B except for the straight outer surface 2A.

  As shown in FIG. 1, the main body 2 includes an inner layer 4 having a flat inner surface 2C made of EPDM and an outer layer 2A made of EPDM and having an outer surface 2A between the reinforcing portions 3 and 3 formed into an arcuate concave surface. 5 and a net-like portion 6 made of a large number of reinforcing yarns arranged between these two layers. The radial thickness of each of the inner layer 4 and the outer layer 5 is appropriately set according to the purpose of use.

The reinforcing yarn of the mesh portion 6 uses an aramid fiber (made of an aramid resin) that is difficult to stretch among fibers to make the hose 1 more difficult to stretch, but may be made of other materials. . When this reinforcing thread is provided in the main body 2, the inner layer 4 is formed by winding a molten strip-shaped tape having a predetermined thickness around a homer (not shown). Reinforcing yarn is drawn out to form a net-like portion, and then a belt-like tape in a molten state having a predetermined thickness is wound thereon to form the outer layer 5 to constitute the main body portion 2. Become. Then, by winding the molten reinforcing portion 3 on the outer layer 5, the hose 1 in which the inner surface 3 </ b> B of the reinforcing portion 3 and the outer surface 2 </ b> A of the main body portion 2 are substantially flush can be formed. As described above, the hose 1 is easily bent between the reinforcing portions 3 and 3 adjacent to each other in the longitudinal direction of the hose, and the reinforcing portion 3 is wound in a spiral shape to be further easily bent.
In addition, the hose longitudinally substantially central portion of the inner surface of the reinforcing portion 3 (a central portion is preferable, but another portion of the inner surface of the reinforcing portion 3 may be used) and the outer surface of the outer layer 5 are reinforced. By providing the spiral reinforcing yarn 7 along the portion 3, it is possible to suppress the hose 1 from expanding outward in the radial direction while suppressing an increase in weight as much as possible. I am doing so. The reinforcing yarn 7 is also made of an aramid fiber (made of an aramid resin) which is difficult to stretch among the fibers, but may be made of other materials. In the figure, a spiral reinforcing thread 7 along the reinforcing portion 3 is provided at the joint portion between the inner surface of the reinforcing portion 3 and the outer surface of the outer layer 5, but the upper side of the mesh portion 6 (the upper side of the mesh portion 6). However, it is also preferable that it be provided on the lower side of the mesh portion 6).

  As shown in FIGS. 1A and 1B, the reinforcing portion 3 corresponds to a diameter connecting an outer surface 3A formed in a semicircular arc shape and both ends of the outer surface 3A in the hose longitudinal direction, and a main body portion. The cross-sectional shape composed of the arc-shaped inner surface 3B gently curved inward in the radial direction and melt-bonded to the outer surface of the outer surface 2 is substantially semicircular, and is made of hard polypropylene, hard polyethylene, or hard polypropylene and hard polyethylene. Of course, it is possible to reduce the weight of the hose 1 when the material is composed of any one of the above two mixtures, or the three kinds of the mixture of hard polypropylene, hard polyethylene, and talc. By using it, the adhesive force with the main body 2 can be increased. In the case of the mixture of the hard polypropylene, the hard polyethylene and talc, when the weight is 100% by weight, it is possible to suppress the adhesive force from being lowered by restraining the talc to 40% by weight or less. Further, by using the arc-shaped inner surface 3B, the bonding area with the main body 2 is increased compared to the inner surface formed linearly, which is advantageous in terms of adhesive strength, but the inner surface is made linear. It may be formed. Moreover, although the figure shows the case where the arc-shaped inner surface 3B of the reinforcing portion 3 does not bite into the main body 2 at all (not embedded), it may be bitten slightly.

  In FIG. 3, the reinforcing portion 3 has a cross-sectional shape comprising an arc-shaped outer surface 3A, an arc-shaped inner surface 3B, and linear lateral side surfaces 3C and 3C for connecting both ends of the inner and outer surfaces 3A and 3B. Shows a case where the reinforcing portion 3 is melt bonded to the main body portion 2 so that the elliptical longitudinal direction is a radial direction (vertical direction, vertical direction in the drawing) as shown in the figure. Yes. In this case, if the outer layer 5 wraps around not only the arc-shaped inner surface 3B of the reinforcing portion 3 but also a part of both lateral side surfaces 3C, 3C, the main body portion 2 and the reinforcing portion 3 There is an advantage that the adhesion area can be increased.

(A) is the side view which made a part of 1st hose the cross section, (b) is the end elevation which shows the upper part of the 1st hose. It is an end view which shows the upper part of the 2nd hose from which the shape of the outer surface of a main-body part differs. It is an end view which shows the upper part of the 3rd hose from which the cross-sectional shape of a reinforcement part differs.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hose 2C Inner surface 2A Outer surface 2 Main-body part 3C Lateral side surface 3B Inner surface 3A Outer surface 3 Reinforcement part 4 Inner layer 5 Outer layer 6 Mesh part

Claims (5)

  An inner surface made of EPDM has a substantially flat inner layer, an outer layer made of EPDM, and a cylindrical main body made of a plurality of reinforcing yarns arranged between the two layers, and a spiral shape on the outer surface of the main body. A helical reinforcing portion wound around and fixed, and the reinforcing portion is composed mainly of at least one of hard polypropylene and hard polyethylene compatible with the main body portion. Pressure-resistant hose characterized by   The pressure-resistant hose according to claim 1, wherein the reinforcing portion is formed by mixing talc with the hard polypropylene or hard polyethylene.   The pressure-resistant hose according to claim 1, wherein the reinforcing portion is formed by mixing the hard polypropylene and the hard polyethylene with talc.   The pressure | voltage resistant hose in any one of Claims 1-3 which equips the junction part of the said reinforcement part and the said outer layer with the helical reinforcement thread | yarn which follows this reinforcement part. The pressure-resistant hose according to any one of claims 1 to 4, wherein a cross-sectional shape of the reinforcing portion is substantially semicircular, and a portion corresponding to a diameter of the reinforcing portion is fixed to an outer surface of the main body portion.

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