JP2014206261A - High pressure hose - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve durability of a high pressure hose having a reinforcing layer, in which metallic wires are mutually braided.SOLUTION: A high pressure hose is provided with one or more metallic wire reinforcing layers formed by braiding metallic wires on an outer periphery of an inner layer tube. The metallic wires are braided by mutually braiding units of belt-like metallic wires formed by parallely aligning three or more metallic wires. In the belt-like metallic wire unit, a wide metallic wire with width larger than height from an outer surface of the inner layer tube is positioned at an outermost side. Height of the wide metallic wire from the outer surface of the inner layer tube is not more than height of the metallic wire positioned on an inner side from the outer surface of the inner layer tube, and width of the wide metallic wire is larger than width of the metallic wire positioned on the inner side.

Description

  The present invention relates to a high-pressure hose reinforced with a metal wire, and particularly to a high-pressure hose having a reinforcing layer formed by braiding a metal wire.

  The high-pressure hose is used for, for example, piping used in a high-pressure state in a drive system that uses a liquid such as water or mineral oil or compressed air as a transmission medium. In particular, among these high-pressure hoses, those used for hydraulic devices are provided with a reinforcing structure composed of a metal wire on the high-pressure hose so that the high-pressure hose can withstand use in an ultra-high pressure state. This reinforcing structure is generally called a spiral structure or a blade structure.

  Patent Document 1 discloses a high-pressure hose having a reinforcing layer having a spiral structure. As shown in FIG. 5, the high-pressure hose 50 has a total of four reinforcing layers 54 having a spiral structure in which a metal wire is spirally wound around an inner tube 52 (in this case, a rubber tube) without gaps. . The high-pressure hose having this spiral structure generally has a problem that it is difficult to handle while having high structural rigidity.

  In addition, as shown in FIG. 6, the blade structure is a structure in which an inner layer is formed by braiding a band-like metal wire in which a plurality of single-wire metal wires (here, three) are arranged in parallel and formed into a band shape (here, in a net-like shape). This is a reinforcing structure wound around the tube 62. The high-pressure hose 60 shown in FIG. 6 includes two reinforcing layers 64 having this blade structure.

JP 2005-308114 A

  Among these reinforcing structures, the high-pressure hose having a braided reinforcing layer has the advantage of being easier to handle than those having a spiral structure, while the metal wire breaks at the intersection of braided metal wires. It also has a structural weakness that is easy to do. Specifically, stress concentrates on the single-wire metal wire located on the outermost side of the strip-shaped metal wire, and repeated bending input is applied to the outermost single-wire metal wire to cause fatigue and fracture. Therefore, in a high-pressure hose having a braided reinforcing layer, it has been desired to improve durability against repeated use in an ultra-high pressure state.

  The present invention has been made in view of the above problems, and an object thereof is to improve the durability of a high-pressure hose having a reinforcing layer formed by braiding metal wires.

  The invention according to claim 1 for solving the above-mentioned problems is a high-pressure hose in which one or a plurality of metal wire reinforcing layers formed by braiding metal wires are provided on the outer peripheral surface of the inner tube, and the braiding of the metal wires. Is made by mutually knitting a band-shaped metal wire in which three or more metal wires are arranged in parallel, and the band-shaped metal wire unit is wider than the height from the outer surface of the inner tube. A large wide metal wire is located on the outermost side, and the height of the wide metal wire from the outer surface of the inner tube is equal to or lower than the height of the inner surface of the metal wire located from the inner surface of the inner tube. The width of the wide metal wire is larger than the width of the metal wire located inside thereof.

  As described above, in a metal wire reinforcing layer in which band-shaped metal wire units are braided with each other, the strongest bending input is generally applied to the outermost metal wire in the other band-shaped metal wire that intersects with one band-shaped metal wire. However, according to this configuration, since the wide metal wire is positioned on the outermost side of the other band-shaped metal wire unit, the load received from one band-shaped metal wire is distributed in the width direction, and the outer surface of the inner tube of the wide metal wire is Fracture due to fatigue of the outermost metal wire due to repeated bending input in the height direction of is suppressed.

  The invention according to claim 2 is the high-pressure hose according to claim 1, wherein the height of the wide metal wire from the outer surface of the inner tube is equal to the height of the metal wire located inside from the outer surface of the inner tube. It is characterized by being substantially identical.

  According to this configuration, the cross-sectional area is secured by the wide metal wire located on the outermost side of the other band-shaped metal wire unit, and the stress concentrated on the outermost metal wire is dispersed, and the height direction from the outer surface of the inner tube Fracture due to fatigue of the outermost metal wire due to repeated bending input to is suppressed. In addition, since the height of the wide metal wire from the inner layer tube is substantially the same as the height of the metal wire located inside, the surface strain of the wide metal wire against the repeated bending input in the height direction is the inner metal wire. Is not increased as compared with the case of arranging them at the outermost side. Therefore, the breakage starting from the outermost metal wire is effectively suppressed, and the durability of the high-pressure hose can be improved.

  According to a third aspect of the present invention, in the high pressure hose according to the second aspect, the inner metal wire is a circular metal wire having a circular cross-sectional shape, and the wide metal wire is the outermost metal in the band-shaped metal wire unit. It is characterized by being located only outside.

  According to this configuration, many conventional circular metal wires can be arranged on the inner side while the durability improving effect of the high-pressure hose is exerted by the wide metal wire positioned only on the outermost side in the band-shaped metal wire unit. Therefore, the number of wide metal wires that need to be separately rolled can be reduced to the minimum number, the additional steps involved in the production of the high-pressure hose can be minimized, and the increase in production cost can be suppressed to the minimum. .

  The invention according to claim 4 is the high-pressure hose according to claim 3, wherein the ratio of the width of the wide metal wire to the height from the outer surface of the inner tube is in the range of 1.5-6. And

  According to this configuration, the wide metal wire having the width / height value of 1.5 or more maintains the durability improvement effect of the high-pressure hose, and the wide metal wire is rolled by the width / height value of 6 or less. Processing is easy. Thereby, while increasing the durability of the high-pressure hose, an increase in production cost related to the production is also suppressed.

  The invention according to claim 5 is the high-pressure hose according to claim 3 or 4, wherein the ratio of the number of wide metal wires to the number of circular metal wires in the band-shaped metal wire unit is in the range of 0.5 to 2. It is characterized by.

  According to this configuration, not only the durability of the high-pressure hose is improved, but also the pressure resistance (breaking pressure) is improved as compared to the case where all the metal wires in the band-shaped metal wire have a circular cross-sectional shape. This is presumed to be an effect due to the increased contact area between the braided strip-shaped metal wires by using a wide metal wire.

  According to the present invention, since the durability of the high-pressure hose having a reinforcing layer formed by braiding a metal wire is improved, it is used in a high-pressure state while utilizing the characteristic of the blade structure that it is relatively easy to handle. The product life of piping can be extended.

1 is a schematic perspective view of a high-pressure hose 10 according to an embodiment of the present invention. (A) It is an enlarged plan view of a part A of FIG. (B) It is the II _B- II _B sectional view taken on the line of FIG. It is a fragmentary sectional view of the reinforcement layer 72 of the conventional high-pressure hose 70. It is sectional drawing for demonstrating the other aspect of a strip | belt-shaped metal wire unit. It is a schematic perspective view for demonstrating the conventional high-pressure hose 50 which has a reinforcement layer of a spiral structure. It is a schematic perspective view for demonstrating the conventional high pressure hose 60 which has a reinforcement layer of a blade structure.

Next, embodiments of the present invention will be described in detail with reference to the drawings. 1 is a schematic perspective view of a high-pressure hose 10 according to the present invention, FIG. 2A is an enlarged plan view of a part A of FIG. 1, and FIG. 2B is II of FIG. _{It is a B-} II _B line sectional view. FIG. 3 is a partial cross-sectional view of the reinforcing layer 72 of the conventional high-pressure hose 70.

  The arrow I indicates the radially inner side of the high-pressure hose, and the arrow O indicates the radially outer side of the high-pressure hose.

  As shown in FIG. 1, the high-pressure hose 10 according to the present embodiment includes a single-layer metal wire reinforcing layer 14 made of a metal wire on the outer peripheral surface of an inner-layer tube 12 through which a high-pressure fluid flows. Yes. The number of metal wire reinforcing layers stacked is not particularly limited, and for example, 1 to 10 reinforcing layers may be stacked. It is also optional to provide an intermediate layer made of synthetic rubber or the like between the reinforcing layer and the reinforcing layer.

  The metal wire reinforcing layer 14 is formed by braiding metal wires on the outer peripheral surface of the inner layer tube 12, and a rubber jacket layer 16 is provided on the outermost layer on the outer surface of the metal wire reinforcing layer 14. Yes. Note that whether or not to provide the outer cover layer 16 is arbitrary in the present invention.

  As shown in FIG. 2 (A), the metal wire reinforcing layer 14 is formed of three metals so as to extend in the longitudinal direction of the inner layer tube 12 (that is, in the direction of arrow 100) while being wound around the inner layer tube 12 in a clockwise direction. Wires are arranged next to each other in parallel to form a band-shaped metal band 20 unit, and this one band-shaped metal wire 20 unit extends in the longitudinal direction of the inner tube 12 (that is, in the direction of arrow 100) while being wound around the inner tube 12 in a left-handed manner. In this way, the other braided metal wires 20 arranged on the inner tube 12 are braided by mutual knitting operation.

  In the present embodiment, the metal wire reinforcing layer 14 is braided in a net-like shape as shown in the figure. However, any braided braid may be used. And the sixth knitted shape (including turtle shell knitted shape).

  The strip-shaped metal wire 20 constituting the metal wire reinforcing layer 14 is composed of three metal wires in the present embodiment. Specifically, as shown in FIG. 2 (B), one wide metal wire 22 is arranged on the outermost side of the band-shaped metal wire 20 unit, and the cross-sectional shape is circular on the inner side. A circular metal wire 24 is arranged.

  As shown in the drawing, the wide metal wire 22 has wide surfaces 22a and 22a which are larger in width (W) than the height (H) from the outer surface of the inner tube 12 and are opposed to each other. The cross-sectional shape of the wide metal wire 22 is a wide cross-sectional shape in which a circle is crushed from both sides in the radial direction and a substantially flat surface facing the both sides is provided, or four corners of a wide rectangle are rounded. is there. That is, the wide surface 22a has a planar shape ranging from a substantially flat surface to a gently curved surface.

The height (H) of the wide metal wire 22 from the outer surface of the inner layer tube 12 is equal to the diameter (l) of the circular metal wire 24. Accordingly, the height (h) of the circular metal wire 24 is equal to the height (H) of the wide metal wire, and the width (w) of the circular metal wire 24 is smaller than the width (W) of the wide metal wire 22. The cross-sectional area of the wire 22 is larger than the cross-sectional area of the circular metal wire 24.

  The ratio of the width (W) of the wide metal wire 22 to the height (H) of the wide metal wire 22 is 1.5 in the present embodiment. This ratio is 1.5 or more from the viewpoint of improving the durability of the high-pressure hose 10 described later. Moreover, it is preferable that it is 6 or less from a viewpoint of making the rolling process of the wide metal wire 22 easy and improving the productivity of the high-pressure hose 10. Especially, it is preferable that the value of (W) / (H) is the range of 1.5-3.

  Any metal wire may be used, but a carbon steel wire is used in the present embodiment.

  Next, a state in which a liquid such as mineral oil is circulated at a high pressure to the high-pressure hose 10 having the above configuration will be described by comparison with a conventional high-pressure hose 70. FIG. 3 is a cross-sectional view of a main part of a reinforcing layer 72 according to a conventional high pressure hose 70. This high-pressure hose 70 is different from the high-pressure hose 10 according to the present invention only in the metal wire constituting the reinforcing layer 72.

  Specifically, in the high-pressure hose 70, four metal wires 74 having a circular cross section are arranged in parallel to form a belt-shaped belt-shaped metal wire 76, and each belt-shaped metal wire 76 is braided in a mesh pattern. A reinforcing layer 72 is configured. Since the metal wire 74 has a circular cross-sectional shape, the ratio of the width (w) to the height (h) of the metal wire 74 related to the high-pressure hose 70 is 1. The height (h) of the metal wire 74 and the height (h) of the circular metal wire 24 according to the present invention are the same height.

According to this conventional high-pressure hose 70, the metal wire 74 located on the outermost side in the other band-shaped metal wire 76 unit that intersects with the one band-shaped metal wire 76 extending in the left-right direction shown in the figure is receiving the contact portion P ₁ height to the starting point (h) strong bending input direction downward with similarly strongly bent contact portion P ₂ from one strip metal wire 74 height starting from (h) in the upward direction Receive input. When the high-pressure fluid repeatedly flows through the high-pressure hose 70, the outermost metal wire 74 gradually fatigues, and finally the outermost metal wire 74 breaks before the other inner metal wires 74.

  On the other hand, according to the high-pressure hose 10 according to the present invention, as shown in FIG. 2 (B), the bending input is strongly applied in the vertical direction which is the height (H) direction at the portion where the strip-shaped metal wires 20 intersect each other. Since the outermost metal wire to be received is the wide metal wire 22, the cross-sectional area is ensured larger than that of the circular metal wire 24, and the stress concentrated on the outermost wide metal wire 22 in the band-shaped metal wire 20 unit is dispersed. In addition, breakage due to fatigue of the outermost metal wire due to repeated bending input in the height (H) direction is also suppressed.

  Further, since the height (H) of the wide metal wire 22 is substantially the same as the height (h) of the circular metal wire, the surface distortion of the wide metal wire 22 with respect to repeated bending input in the height (H) direction is circular. There is no increase compared to the case where the metal wire 24 is arranged on the outermost side. Therefore, the breakage starting from the outermost metal wire is effectively suppressed, and the durability of the high-pressure hose 10 can be improved.

  In addition, according to the present embodiment, only the metal wire arranged on the outermost side of the band-shaped metal wire 20 unit is the wide metal wire 22, and the conventional circular metal wire 24 is arranged on the inner side. Many conventional circular metal wires can be arranged on the inner side while the durability improving effect of the high-pressure hose 10 is exhibited by the wide metal wire 22 arranged on the outermost side. Therefore, the number of the wide metal wires 22 that need to be separately rolled can be reduced to the minimum two, minimizing the additional steps related to the production of the high-pressure hose 10 and suppressing the increase in production cost to the minimum. be able to.

  In particular, when increasing the number of metal wires constituting the band-shaped metal wire unit, the effect of suppressing the increase in production cost and minimizing the additional process is great. FIG. 4 is a cross-sectional view for explaining another embodiment of the band-shaped metal wire unit. As shown in the figure, the band-shaped metal wire 80 unit is composed of six metal wires, one wide metal wire 22 is disposed only on the outermost side, and four circular metal wires 24 having a circular cross section are disposed on the inner side. Yes.

According to this configuration, when the reinforcing layer having the blade structure is applied to the high-pressure hose, the number of the wide metal wires 22 used can be reduced with respect to the number of the circular metal wires 24 used, and an increase in production cost is greatly suppressed. . In addition, since it is not necessary to roll the inner circular metal wire, a large number of circular metal wires having a large tensile strength value can be used for the inner metal wire. It is also possible to increase the (breaking pressure).

  In the present invention, the wide metal wire 22 may be disposed on the outermost side and the circular metal wire 24 may be disposed on the inner side in the band-shaped metal wire 20 unit, and the number thereof is not limited. However, the ratio of the number of the wide metal wires 22 to the number of the circular metal wires 24 in the belt-shaped metal wire 20 unit is preferably in the range of 0.5-2.

  If it is this range, in addition to the durability improvement effect of the high-pressure hose 10 as shown in the Example mentioned later, compared with the case where all the strip | belt-shaped metal wire units are set to the circular metal wire 24, the pressure resistance (breaking pressure) improvement effect It is because it is obtained. This is presumed to be because the use of wide metal wires increases the contact area between the braided strip metal wires.

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the invention.

  For example, in the above-described embodiment, the metal wire positioned inside in the band-shaped metal wire unit is the circular metal wire 24 having a circular cross-sectional shape, but may have other shapes such as a substantially rectangular cross section and an elliptical cross section.

  In that case, the height (H) of the wide metal wire located on the outermost side is equal to or lower than the height (w) of the inner metal wire from the outer surface of the inner tube 12, and the width (W) is the inner metal. It may be larger than the width (w) of the wire. Even in this case, when a strong bending input is applied to the outermost wide metal wire in the other band metal wire intersecting with the one band metal wire, the load received from the other metal wire is dispersed in the width direction, Breakage due to fatigue of the outermost metal wire due to repeated bending input in the height (H) direction of the wide metal wire is suppressed. Therefore, the effect of the present invention that the durability of the high-pressure hose is improved can be obtained.

  In addition, it is not essential in the practice of the present invention that the cross-sectional area of the wide metal wire is larger than the cross-sectional area of the inner metal wire.

  However, it is preferable that the height (H) of the wide metal wire is substantially the same as the height (h) of the inner metal wire from the outer surface of the inner tube 12, and the cross-sectional area of the wide metal wire is the same as that of the inner metal wire. The fact that it is preferably larger than the cross-sectional area is as described in the above embodiment.

Hereinafter, the present invention will be described with reference to examples.
1. Production of high-pressure hose One metal wire reinforcing layer was formed by braiding metal wires made of carbon steel wires into a blade shape on the outer surface of the inner tube. The outer side of the reinforcing layer was further covered with a nylon jacket to form a high-pressure hose.

  Table 1 shows the hose diameter of the high-pressure hose thus configured, the arrangement of the wide metal wire and the circular metal wire in the band-shaped metal wire unit, the width (W) of the wide metal wire, the height of the wide metal wire from the outer surface of the inner layer tube (H), diameter of circular metal wire (l), value of (W) / (H), number of wide metal wires with respect to the number of circular metal wires in strip metal wire unit, fracture pressure index, and impulse durability life index Write.

  In addition, between Example 1 and Comparative Example 1 to compare, Examples 2-3 and Comparative Example 2, and Examples 4-5 and Comparative Example 3, all the widths of the total metal wire in each braid unit are the same. It was.

2. Measurement of burst pressure [1. The pressure resistance test according to JIS K6330-2 was performed on the high-pressure hose prepared according to [Preparation of high-pressure hose], and the breaking pressure of the high-pressure hose was measured. Table 1 shows the breaking pressure of the high-pressure hose according to the example by the ratio when the value of the corresponding comparative example is 100.

3. Measurement of impulse durability life [1. For the high-pressure hose prepared according to [Preparation of high-pressure hose], an impact pressure test in accordance with JIS K6330-8 was performed, and the number of pressure tests performed until the high-pressure hose burst was recorded. Table 1 shows the number of pressure tests of the high-pressure hose according to the example by the ratio when the number of pressure tests of the corresponding comparative example is 100.

[result]
As shown in Table 1, when Examples 1 to 5 according to the present invention were compared with Comparative Examples 1 to 3 corresponding to the respective examples, it was found that the durability life was increased in the examples.

  Further, when the ratio of the wide metal wire to the number of circular metal wires in the band-shaped metal wire is in the range of 0.5 to 2 (Examples 1 to 4), the fracture pressure is also improved as compared with the corresponding Comparative Examples 1 to 3. It was confirmed.

DESCRIPTION OF SYMBOLS 10 High pressure hose 12 Inner-layer tube 20, 80 Strip-shaped metal wire 22 Wide metal wire 22a Wide surface 24 Circular metal wire

Claims (5)

In the high-pressure hose in which one or more metal wire reinforcing layers braided metal wires are provided on the outer peripheral surface of the inner layer tube,
The braiding of the metal wire is performed by mutually knitting a band-shaped metal wire in which three or more metal wires are arranged in parallel, in units of the band-shaped metal wire,
The band-shaped metal wire unit is such that a wide metal wire having a width larger than the height from the outer surface of the inner tube is located on the outermost side,
The height of the wide metal wire from the outer surface of the inner layer tube is equal to or less than the height of the metal wire located inside from the outer surface of the inner layer tube, and the width of the wide metal wire is located inside the metal wire A high-pressure hose characterized by being larger than the width.   2. The high-pressure hose according to claim 1, wherein a height of the wide metal wire from the outer surface of the inner layer tube is substantially the same as a height of the metal wire located inside from the outer surface of the inner layer tube. The inner metal wire is a circular metal wire having a circular cross-sectional shape,
The high-pressure hose according to claim 2, wherein the wide metal wire is located only on the outermost side in the band-shaped metal wire unit.   The high-pressure hose according to claim 3, wherein a ratio of the width of the wide metal wire to the height from the outer surface of the inner tube is in the range of 1.5-6.   5. The high-pressure hose according to claim 3, wherein a ratio of the number of wide metal wires to the number of circular metal wires in the band-shaped metal wire unit is in a range of 0.5 to 2. 5.

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