hose

Abstract

Compared to conventional technology, this technology improves the pressure resistance of the hose while also increasing its durability. [Solution] The hose comprises an inner tube, a reinforcing layer positioned radially outside the inner tube and formed by spirally winding a steel cord, and an outer layer positioned radially outside the reinforcing layer, wherein the steel cord has multiple twisted layers formed by twisting together multiple filaments, and the twisting direction of the filaments of adjacent twisted layers is the same.

Description

Technical Field

[0001] The present disclosure relates to a hose.

Background Art

[0002] High-pressure hoses with high-pressure resistance and flexibility are used in construction machinery, machine tools, power steering of automobiles, measuring instruments, etc.

[0003] Generally, a high-pressure hose is configured by laminating a plurality of reinforcing layers on the outer periphery of an inner rubber or resin layer. Fibers such as single-wire wires, nylon, and polyester are often used as the reinforcing material for the reinforcing layer.

[0004] In the currently required operating pressure range for high-pressure hoses, it is an area where a single-wire wire can sufficiently cope, and in fact, steel cords that require the labor and effort of twisting steel filaments have generally not been used.

[0005] However, with the increasing high pressure of recent hydraulic systems, hydraulic hoses used in construction machinery and the like tend to require even higher high-pressure resistance. If the future required high-pressure range is to be achieved with a single-wire wire, it is expected that problems such as the hose becoming harder and the handling during installation becoming difficult will arise.

[0006] In order to impart corresponding high strength and flexibility to a high-pressure hose that requires even higher high-pressure resistance, there is a limit with a single-wire wire (steel filament). For this reason, it is desired to apply a steel cord obtained by twisting steel filaments used for reinforcing tires to a high-pressure hose.

[0007] Patent Document 1 describes an aspect in which a layer of steel cord formed by braiding is used on the surface of the pressure-resistant reinforcing layer of a hose in order to suppress elongation according to a tensile load.

[0008] Furthermore, Patent Document 2 describes an embodiment in which the winding direction of the steel cords in each layer of the reinforcing layer constituting the hose is set to be different from that of the other in order to improve the impact resistance of the hose. [Prior art documents] [Patent Documents]

[0009] [Patent Document 1] Japanese Patent Publication No. 2006-220290 [Patent Document 2] International release WO2018 / 164082 [Overview of the project] [Problems that the invention aims to solve]

[0010] This disclosure aims to improve the durability of a hose while increasing its pressure resistance compared to conventional technology. [Means for solving the problem]

[0011] A hose according to a first aspect of the present disclosure comprises an inner tube, a reinforcing layer disposed radially outside the inner tube and formed by spirally winding a steel cord, and an outer layer disposed radially outside the reinforcing layer, wherein the steel cord has a plurality of twisted layers formed by twisting a plurality of filaments together, and the twisting direction of the filaments of adjacent twisted layers is the same.

[0012] In the hose of the first aspect of this disclosure, the twist direction of the filaments of adjacent twisted layers in the steel cord is the same. As a result, in the hose, the direction in which the twists of each filament of adjacent twisted layers in the steel cord tighten and the direction in which they untwist are the same, making it possible to suppress the occurrence of defects in the steel cord. By suppressing the occurrence of defects in the steel cord in this way, the pressure resistance of the hose can be increased and the durability of the hose can be improved.

[0013] A hose according to a second aspect of the present disclosure, wherein the steel cord has three or more twisted layers, and the twist direction of the filaments is the same in all of the twisted layers.

[0014] In the hose of the second aspect of this disclosure, the twist direction of the filaments in all strands of the steel cord is the same. Therefore, in the above hose, compared to a configuration in which, for example, the twist direction of the filaments in some strands differs from the twist direction of the filaments in other strands, it is possible to effectively suppress the occurrence of defects in the steel cord.

[0015] A third aspect of the present disclosure is a hose in the first aspect, wherein the steel cord has three or more twisted layers, and the outermost twisted layer and the twisted layers adjacent to the outermost twisted layer radially inward have the same twisting direction of the filaments.

[0016] In the hose of the third aspect of this disclosure, the twist direction of the filaments in the outermost twisted layer and the adjacent twisted layers radially inward of the outermost twisted layer are the same. Therefore, in the hose described above, the twist direction of the filaments in the twisted layers other than the outermost twisted layer and the adjacent twisted layers radially inward of the outermost twisted layer can be freely set while suppressing deterioration of the appearance.

[0017] A fourth aspect of the present disclosure is a hose in any one of the first to third aspects, wherein the steel cord is twisted in a direction that untwists the filaments forming the outermost twisted layer.

[0018] In the hose of the fourth aspect of this disclosure, the steel cord is twisted in a direction that unravels the twist of the filaments forming the outermost twisted layer, thereby suppressing the occurrence of kinks (bending deformation) as a defect in the steel cord.

[0019] The hose according to the fifth aspect of the present disclosure is the hose according to any one of the first to third aspects, wherein the steel cord is twisted in the direction in which the twisting of the filaments forming the outermost twisted layer is tightened.

[0020] In the hose according to the fifth aspect of the present disclosure, since the steel cord is twisted in the direction in which the twisting of the filaments forming the outermost twisted layer is tightened, it is possible to suppress the filaments of the outermost twisted layer from untwisting as a defect of the steel cord.

Advantages of the Invention

[0021] According to the present disclosure, compared with the prior art, it is possible to enhance the pressure resistance of the hose while enhancing the durability of the hose.

Brief Description of the Drawings

[0022] [Figure 1] FIG. 1 is a view showing the structure of the hose according to the first embodiment, and is a perspective view showing an internal state with a part broken. [Figure 2] FIG. 2 is a view showing the structure of the hose according to the second embodiment, and is a perspective view showing an internal state with a part broken. [Figure 3] FIG. 3 is a view showing the structure of the hose according to the third embodiment, and is a perspective view showing an internal state with a part broken. [Figure 4A] FIG. 4A is a plan view of the steel cord. [Figure 4B] FIG. 4B is a cross-sectional view of the steel cord. [Figure 4C] FIG. 4C is a plan view of the wire. [Figure 5] FIG. 5 is a view showing a cross-section of the hose according to the first embodiment. [Figure 6] FIG. 6 is a view showing a cross-section of the hose according to the second embodiment. [Figure 7] FIG. 7 is a view showing a cross-section of the hose according to the third embodiment. [Figure 8A]Figure 8A is a partial longitudinal cross-sectional view showing the state of the hose before the hose fitting is crimped to the end of the hose. [Figure 8B] Figure 8B is a partial longitudinal cross-sectional view showing the state after the hose fitting has been fixed to the end of the hose by crimping. [Figure 9A] Figure 9A is a diagram illustrating the twisting direction of the filaments that make up the steel cord. [Figure 9B] Figure 9B is a diagram illustrating the twisting direction of the filaments that make up the steel cord. [Figure 10A] Figure 10A is a diagram illustrating the winding direction of the steel cord. [Figure 10B] Figure 10B is a diagram illustrating the winding direction of the steel cord. [Modes for carrying out the invention]

[0023] The following describes the hose configuration for implementing this disclosure, based on the drawings. Components indicated by the same reference numerals in each drawing are considered to be the same or similar components. In the embodiments described below, redundant descriptions and reference numerals may be omitted. Furthermore, the drawings used in the following description are all schematic, and the dimensional relationships and ratios of the elements shown in the drawings do not necessarily correspond to reality. Also, the dimensional relationships and ratios of the elements do not necessarily correspond between multiple drawings.

[0024] (First Embodiment) Figure 1 is a diagram showing the structure of the hose 10 of the first embodiment, and is a perspective view showing the internal state with a portion of it broken.

[0025] <Overall hose configuration> Figures 4A and 4B show a plan view and a cross-sectional view of the steel cord 110, respectively, and Figure 4C is a plan view of the wire 120.

[0026] Figure 5 is a cross-sectional view of the hose 10 of the first embodiment.

[0027] Hose 10 can be used for any application that involves circulating a high-pressure fluid such as hydraulic oil.

[0028] The hose 10 comprises an inner pipe 11, a plurality (for example, four) of reinforcing layers 1S, 2S, 3S, and 4S arranged radially outside the inner pipe 11, and an outer surface layer 12 arranged radially outside these multiple reinforcing layers 1S, 2S, 3S, and 4S. Specifically, the multiple reinforcing layers 1S, 2S, 3S, and 4S are sequentially laminated on the outer surface of the inner pipe 11. The outer surface layer 12 is formed on the outer surface of the multiple reinforcing layers 1S, 2S, 3S, and 4S.

[0029] The inner pipe 11, the multiple reinforcing layers 1S, 2S, 3S, 4S, and the outer layer 12 are each arranged to be coaxial with the longitudinal central axis 10C of the hose 10.

[0030] Intermediate layers 13, 14, and 15 are interposed between the multiple reinforcing layers 1S, 2S, 3S, and 4S, respectively.

[0031] The inner tube 11 is made of, for example, rubber, resin, etc., and a high-pressure fluid such as hydraulic oil flows through its interior. The inner tube 11 functions as a component that ensures airtightness of the flowing fluid.

[0032] The multiple reinforcing layers 1S, 2S, 3S, and 4S function as components that hold fluid pressure.

[0033] The intermediate layers 13, 14, and 15 are composed of, for example, rubber, resin, adhesive, etc., and function as components that prevent wear caused by contact between the reinforcing layers 1S, 2S, 3S, and 4S.

[0034] The outer layer 12 is composed of, for example, rubber, resin, etc., and functions as a component that protects the reinforcing layers 1S, 2S, 3S, and 4S from the external environment, while also ensuring the aesthetic appearance of the hose 10.

[0035] Each of the multiple reinforcing layers 1S, 2S, 3S, and 4S is composed of a steel cord reinforcing layer 110S, which uses a steel cord 110 made by twisting together multiple filaments 111 as a metal reinforcing material.

[0036] The multiple reinforcing layers 1S, 2S, 3S, and 4S each include an outer reinforcing layer 10U on the side closer to the outer surface layer 12 and an inner reinforcing layer 10L on the side closer to the inner pipe 11.

[0037] The outer reinforcing layer 10U is composed of reinforcing layers 1S and 2S, and the inner reinforcing layer 10L is composed of reinforcing layers 3S and 4S.

[0038] In the steel cord reinforcement layer 110S, the steel cord 110 is wound spirally along the longitudinal direction of the hose 10. In other words, the steel cord reinforcement layer 110S is constructed by winding the steel cord 110 spirally.

[0039] Figures 8A and 8B show partial longitudinal sections of the hose before and after the hose fitting 20 is fixed to the end of the hose 10 by crimping.

[0040] The hose fitting 20 consists of a core fitting 21 and a fastening fitting 22 equipped with crimping claws. The area to be crimped by the fastening fitting 22 is indicated by a dashed line K.

[0041] The claws of the fastening fitting 22 bite into the outer layer 12 and the outermost reinforcing layer 4S of the hose 10, thereby fixing the hose 10 to the hose fitting 20.

[0042] <Main components of the hose> As described above, the steel cord reinforcement layer 110S is constructed by winding the steel cord 110 in a spiral shape. As shown in Figure 4B, the steel cord 110 has multiple twisted layers 112 formed by twisting together multiple filaments 111. In this embodiment, as an example, the steel cord 110 has three twisted layers 112, resulting in a 3+9+15 twisted structure. Specifically, the steel cord 110 has a core first twisted layer 112A formed of three filaments 111. A second twisted layer 112B, formed of nine filaments 111, is formed on the outer circumference of the first twisted layer 112A. A third twisted layer 112C, formed of fifteen filaments 111, is formed on the outer circumference of the second twisted layer 112B.

[0043] Figure 9A shows the Z-twist (left-hand twist) of multiple filaments 111, and Figure 9B shows the S-twist (right-hand twist) of multiple filaments 111.

[0044] As shown in Figure 9A, when the filaments 111 of the steel cord 110 are twisted in a Z-twist, the twisting direction RZ of the filaments 111 is to the right with respect to the axis of the steel cord 110.

[0045] As shown in Figure 9B, when the filaments 111 of the steel cord 110 are twisted in an S-twist, the twisting direction RS of the filaments 111 is to the left with respect to the axis of the steel cord 110.

[0046] In this embodiment of the steel cord 110, the first twisted layer 112A is Z-twisted, the second twisted layer 112B is Z-twisted, and the third twisted layer 112C is Z-twisted. That is, in this embodiment of the steel cord 110, the twist direction of the filaments 111 of the adjacent first twisted layer 112A and second twisted layer 112B is the same Z-twist, and the twist direction of the filaments 111 of the adjacent second twisted layer 112B and third twisted layer 112C is the same Z-twist. Furthermore, in the steel cord 110, the outermost third twisted layer 112C and the second twisted layer 112B, which is radially inward from the third twisted layer 112C, have the same Z-twist of the filaments 111. In this embodiment of the steel cord 110, the twist direction of the filaments 111 is the same in all three twisted layers 112.

[0047] Next, we will explain how to wrap the steel cord 110. Figure 10A shows the steel cord 110 in a Z-winding (right-hand winding) configuration, and Figure 10B shows the steel cord 110 in an S-winding (left-hand winding) configuration.

[0048] As shown in Figure 10A, when the steel cord 110 is wound in a Z-wind along the longitudinal central axis 10C of the hose 10, the winding direction VZ of the steel cord 110 will be to the right with respect to the longitudinal central axis 10C of the hose 10. For example, it will be wound to the right of the longitudinal central axis 10C of the hose 10 at a static angle of 54.7°.

[0049] As shown in Figure 10B, when the steel cord 110 is wound in an S-shape along the longitudinal central axis 10C of the hose 10, the winding direction VS of the steel cord 110 will be to the left with respect to the longitudinal central axis 10C of the hose 10. For example, it will be wound to the left of the longitudinal central axis 10C of the hose 10 at a static angle of 54.7°.

[0050] Note that in Figures 10A and 10B, the winding direction is shown using a single steel cord 110 as a representative example for illustrative purposes.

[0051] By adjusting the twisting directions RZ and RS of the outermost third twist layer 112C of the steel cord 110, and the winding directions VZ and VR of the steel cord 110, the steel cord 110 can be twisted in a direction that untwists the filaments 111, or in a direction that tightens the filaments 111. That is, the steel cord 110 may be twisted in a direction that untwists the filaments 111 forming the outermost third twist layer 112C, or it may be twisted in a direction that tightens the filaments 111 forming the third twist layer 112C.

[0052] Here, twisting refers to the phenomenon in which the steel cord 110 is distorted by a force acting on it in the circumferential direction. When the hose 10 is disassembled and the steel cord 110 is removed, the steel cord 110 rotates in the direction that releases the twist, so the direction in which the steel cord 110 is twisted can be determined.

[0053] Furthermore, twisting the steel cord 110 in the direction that untwists it is called twisting in the negative direction, and twisting the steel cord 110 in the direction that tightens it is called twisting in the positive direction. In other words, the direction in which the steel cord 110 untwists is the direction in which it is twisted in the negative direction from the amount of twist that is initially applied to the steel cord 110 (for example, 0), and the direction in which the steel cord 110 tightens is the direction in which it is twisted in the positive direction from the amount of twist that is initially applied to the steel cord 110 (for example, 0).

[0054] Here, twisting occurs during the manufacturing process in which the steel cord 110 is wound in a spiral shape. If twisting occurs in the steel cord 110, there is a risk of a decrease in breaking strength and a decrease in breaking elongation.

[0055] In this embodiment, by taking into account the twisting that occurs during the manufacturing process and keeping the amount of twisting applied to the steel cord 110 of the manufactured hose 10 within a predetermined range, it is possible to improve the pressure resistance and durability of the hose 10.

[0056] (Second Embodiment) Figure 2 shows the structure of the hose 10 of the second embodiment, with a portion cut open to show the internal state in a perspective view. Figure 6 shows a cross-section of the hose 10 of the second embodiment.

[0057] In the second embodiment, the same reference numerals are used for components similar to those in the first embodiment, redundant explanations are omitted as appropriate, and only the parts that differ from the first embodiment are described.

[0058] In the second embodiment, the hose 10 has an outer reinforcing layer 10U which includes a steel cord reinforcing layer 110S, and an inner reinforcing layer 10L which includes a wire reinforcing layer 120S. The other components of the hose 10 are the same as those of the hose 10 in the first embodiment.

[0059] The hose 10 of the second embodiment is composed of a combination of a wire reinforcement layer 120S, which uses a single wire 120 as a metal reinforcement material, and a steel cord reinforcement layer 110S.

[0060] In the wire reinforcement layer 120S, a single wire 120 is wound spirally along the longitudinal direction of the hose 10. In other words, the wire reinforcement layer 120S is constructed by winding the wire 120 spirally.

[0061] (Third embodiment) Figure 3 shows the structure of the hose 10 of the third embodiment, with a portion cut open to show the internal state in a perspective view. Figure 7 shows a cross-section of the hose 10 of the third embodiment.

[0062] In the third embodiment, the same reference numerals are used for components similar to those in the first embodiment, redundant explanations are omitted as appropriate, and only the parts that differ from the first embodiment are described.

[0063] In the third embodiment, the hose 10 has an outer reinforcing layer 10U which includes a wire reinforcing layer 120S, and an inner reinforcing layer 10L which includes a steel cord reinforcing layer 110S. The other components of the hose 10 are the same as those of the hose 10 in the first embodiment.

[0064] The hose 10 of the third embodiment is composed of a combination of a wire reinforcement layer 120S, which uses a single wire 120 as a metal reinforcement material, and a steel cord reinforcement layer 110S.

[0065] Next, we will explain the effects and advantages common to the first, second, and third embodiments.

[0066] In the hose 10 of this embodiment, by using a steel cord reinforcement layer 110S as the reinforcing layer, it is possible to provide high strength and flexibility to high-pressure hoses that require even greater pressure resistance.

[0067] In the hose 10 of this embodiment, the twist direction of the filaments 111 of adjacent twisted layers 112 in the steel cord 110 is the same. Therefore, in the hose 10, the direction in which the twists of each filament 111 of adjacent twisted layers 112 in the steel cord 110 tighten and untwist is the same, making it possible to suppress the occurrence of defects in the steel cord 110. By suppressing the occurrence of defects in the steel cord 110 in this way, the pressure resistance of the hose 10 can be increased and the durability of the hose 10 can be increased. In addition, in the first and second embodiments, the appearance of the steel cord 110 is also improved.

[0068] In the hose 10 of the first and second embodiments, the twist direction of the filaments 111 in the outermost third twist layer 112C and the second twist layer 112B of the steel cord 110 is the same. Therefore, in the hose 10 described above, the twist direction of the filaments 111 in the twist layers other than the third twist layer 112C and the second twist layer 112B (first twist layer 112A in this embodiment) can be freely set while suppressing deterioration of the appearance.

[0069] In the hose 10 of the first to third embodiments, the twist direction of the filaments 111 of all twisted layers 112 in the steel cord 110 is the same. Therefore, in the above hose, compared to a configuration in which, for example, the twist direction of the filaments 111 of some twisted layers 112 differs from the twist direction of the filaments 111 of other twisted layers 112, it is possible to effectively suppress the occurrence of defects in the steel cord 110.

[0070] In the hose 10 of the first to third embodiments, if the steel cord 110 is twisted in a direction that untwists the filaments forming the outermost third twisted layer 112C, it is possible to suppress the occurrence of kinking (bending deformation) as a defect in the steel cord 110.

[0071] Furthermore, in the hose 10 of the first to third embodiments, the steel cord 110 is twisted in a direction that tightens the twist of the filaments 111 that form the outermost third twisted layer 112C. Therefore, it is possible to suppress the untwisting of the filaments 111 of the outermost third twisted layer 112C, which is a defect of the steel cord 110.

[0072] In the hose 10 of the embodiment described above, the steel cord 110 had a three-layer structure, but this disclosure is not limited to this configuration. For example, the steel cord 110 may have a two-layer structure or a structure of four or more layers.

[0073] The structure of the steel cord used in one embodiment of the present disclosure is not particularly limited. For example, the steel cord may be an M+N structure in which N sheath filaments (where N is an integer greater than 1) are spirally twisted around M core filaments (where the core filaments may be twisted together or bundled together without twisting), or it may be a multi-twist structure in which multiple M+N structures are further twisted together. [Explanation of Symbols]

[0074] 1S, 2S, 3S, 4S reinforcement layer 10 hoses 110 Steel Code 111 Filaments 112 strands

Claims

1. Inner tube and A reinforcing layer is positioned radially outward of the inner tube and is formed by spirally winding a steel cord, An outer layer disposed radially outward from the reinforcing layer, Equipped with, The steel cord has multiple twisted layers formed by twisting together multiple filaments, The twist direction of the filaments in adjacent twist layers is the same. hose.

2. The hose according to claim 1, wherein the steel cord has three or more twisted layers, and the twist direction of the filaments is the same in all of the twisted layers.

3. The hose according to claim 1, wherein the steel cord has three or more twisted layers, and the outermost twisted layer and the twisted layers adjacent to the outermost twisted layer radially inward have the same twisting direction of the filaments.

4. The hose according to any one of claims 1 to 3, wherein the steel cord is twisted in a direction that untwists the filaments forming the outermost twisted layer.

5. The hose according to any one of claims 1 to 3, wherein the steel cord is twisted in a direction that tightens the twist of the filaments forming the outermost twisted layer.

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