JP2001032966A - High pressure rubber hose - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high pressure hose which can endure high pressure and large tensile strength, effectively avoid damages at the terminal section of a fixture and is rich in flexibility. SOLUTION: This high pressure rubber hose 1a comprises four steel wire spiral reinforcing layers 12a, 12b, 12c and 12d comprising rubber layers 5a and 5b intervening among an internal face rubber layer 2, center cloth 3 and an external layer 4 to bear internal pressure, two steel wire spiral reinforcing layers 13a and 13b to bear tensile loads arranged. The steel wire turning angles αa-αd of the steel wire spiral reinforcing layers 12a, 12b, 12c and 12d to bear internal pressure are set to 103-120 deg., the same as those of conventional general purpose hoses, and the steel wire turning angles αe-αf of the steel wire spiral reinforcing layers 13a and 13b to bear tensile loads are set to 90-103 deg., and the turning angle of a layer to bear a tensile load is set so as to become smaller than the minimum turning angle of the layers to bear internal pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-pressure rubber hose used by connecting several assembly hoses each having a metal fitting to both ends of a single length rubber hose of 20 m or 40 m and wound around a reel. The present invention relates to a high-pressure rubber hose used in civil engineering machines and the like that require bending, tension, and bending deformation at a part.

[0002]

2. Description of the Related Art Conventionally, as a low-elongation high-pressure rubber hose used in construction machines, civil engineering machines, and the like, in which internal pressure, tensile load, and bending act simultaneously and repeatedly wind and unwind around reels, etc. As shown in FIG. 6, several high-pressure rubber hoses 1 are used by connecting several assembly hoses each having a metal fitting 20 attached to both ends thereof. Such a high-pressure rubber hose 1 has, for example, a structure as shown in FIGS. Various structures have been proposed.

For example, in the case of a general-purpose high-pressure rubber hose 1 as shown in FIG. 2, an interlayer rubber layer 5 is interposed between an inner rubber layer 2, a center cloth 3 and an outer rubber layer 4 so that the internal pressure is increased. Six layers of steel wire spiral reinforcement layers 7a and 7 that serve as burden layers
b, 7c, 7d, 7e, 7f are arranged, and the steel wire winding angles α _{a to} α _f of the steel wire spiral reinforcing layers 7a to 7f are:
and it is configured such that _{α a <α b <α c} <α d <α e <α f.

As another conventional example, as shown in FIG. 3, an inner pressure bearing layer is provided by interposing an interlayer rubber layer 5 between the inner rubber layer 2 and the center cloth 3 and the outer rubber layer 4. Steel wire spiral reinforcing layers 8a, 8b, 8c, 8d
And a steel wire braided layer 9 serving as a tensile load-bearing layer, the steel wire spiral reinforcing layers 8a, 8b, 8
The steel wire winding angles α _{a to} α _d of c and 8d are α _a <α _b <
The configuration is such that α _c <α _d .

[0005] Further, the conventional example shown in FIG.
The two steel wire braided layers 10a and 10b serving as internal pressure bearing layers and the tensile load bearing layer 1 between
And a steel wire braided layer 10c, and the conventional example shown in FIG. 5 is provided between the inner rubber layer 2 and the outer rubber layer 4.
Two steel wire braided layers 11a and 11b serving as internal pressure bearing layers
And one layer of a yarn braided layer 11c serving as a tensile load bearing layer.

[0006]

However, the general-purpose high-pressure rubber hose 1 as shown in FIG. 2 is composed of only the internal pressure-bearing layer. Becomes very large, and the inner diameter of the hose body becomes thin, so that the original state cannot be restored even if the load is removed later.

In the case of the high-pressure rubber hose shown in FIG. 3, a steel wire braided layer 9 serving as a tensile load-bearing layer is disposed on the outermost layer. Because of the limitation of 0.4 mm or less in the diameter of the work, the tensile strength is insufficient, and the steel wire braided layer 9 is
There is a problem that it is damaged at the metal fitting terminal portion 20a.

Further, in the case of a high-pressure rubber hose shown in FIG. 4 comprising two steel wire braided layers 10a and 10b serving as internal pressure bearing layers and one steel wire braided layer 10c serving as a tensile load bearing layer, There are problems that the pressure resistance is insufficient and buckling easily occurs.

In the case of a high-pressure rubber hose shown in FIG. 5 comprising two steel wire braided layers 11a and 11b serving as internal pressure bearing layers and a single yarn braided layer 11c serving as a tensile load bearing layer. Due to insufficient pressure and insufficient tensile strength, elongation with respect to the load is large, and there is a problem that the original state is not restored even when the load is removed.

As described above, all of the conventional high-pressure hoses have various problems.

An object of the present invention is to provide a high-pressure hose which can withstand high pressure, has a large tensile strength, can effectively prevent breakage at metal fitting ends, and is highly flexible.

[0012]

According to the present invention, at least two layers on the inner rubber layer side of the steel wire spiral reinforcing layer are used as internal pressure bearing layers, and at least two layers on the outer periphery thereof are formed. The gist of the present invention is that the tension load-bearing layer is configured such that the winding angle of the tensile load-bearing layer is set smaller than the winding angle of the internal pressure-bearing layer.

According to the present invention, since the internal pressure bearing layer is made of a steel wire spiral as described above, it can withstand high pressure, and the tensile load bearing layer is made of a steel wire spiral. The diameter of the steel wire is not particularly limited, and it is possible to use a steel wire thicker than 0.4 mm, which increases the tensile strength and effectively prevents breakage at the metal fitting end. is there. Furthermore, since the steel wire density of the tensile load bearing layer is set to 70 to 90%, it can be easily wound around a reel with high flexibility.

[0014]

Embodiments of the present invention will be described below with reference to the accompanying drawings. The same components as those of the conventional example are denoted by the same reference numerals, and description thereof will be omitted.

FIG. 1 is a partially cutaway front view showing a reinforcing structure of a reel wound high pressure hose embodying the present invention.
This high-pressure rubber hose 1a has a four-layer steel wire spiral reinforcing layer which serves as an internal pressure bearing layer with interlayer rubber layers 5a and 5b interposed between the inner rubber layer 2, the center cloth 3 and the outer rubber layer 4. 12a, 12b, 12c, 12d and two layers of steel wire spiral reinforcing layers 13a, 1 serving as tensile load bearing layers
3b, and the internal pressure-bearing layer and the tensile load-bearing layer are desirably set to two or more even layers in view of the bunras.

The steel wire winding angles α _{a to} α _d of the four steel wire spiral reinforcing layers 12a, 12b, 12c and 12d serving as the internal pressure bearing layers are the same as those of the conventional general-purpose hose, ie, 103 °.
The steel wire winding angles α _e and α _f of the two steel wire spiral reinforcing layers 13a and 13b serving as tensile load bearing layers are set to 90 ° to 103 °, and the tensile load bearing is set. The winding angle of the layer is set to be smaller than the minimum winding angle of the internal pressure bearing layer.

That is, in a general high-pressure hose, when a tensile load is applied from one end of the hose, the winding angle of the reinforcing layer of the hose changes, and as a result, the hose elongates.
At this time, the larger the winding angle is, the more easily it changes, and the smaller the winding angle is, the harder it is to change. That is, when a tensile load is applied, a material having a small winding angle is apt to receive a tensile load, and a material having a large winding angle is easily changed (elongated). It becomes difficult to receive the load.

Therefore, unless the winding angle of the tension load-bearing layer is smaller than the winding angle of the internal pressure-bearing layer as described above, the tensile load must be received by the internal pressure-bearing layer. The pressure-bearing layer is apt to be broken due to a load obtained by adding a tensile load to the internal pressure of the hose. In order to prevent this, the winding angle is set as described above. This is schematically shown in FIG.

That is, if the steel wire (A) α is a small winding angle (tensile load-bearing layer) and the steel wire (B) β is a large winding angle (internal pressure-bearing layer), each layer is now free. Assuming you can move to
By pulling the hose, (A), (B)
Moves to (A ′) and (B ′). At that time, the elongation amount of the hose relation K _A, K _B is a K _A <K _B. Since the actual hose elongation is the same for both layers, (B)
There will be no tensile load on the layer.

For the above reasons, the winding angle from the internal pressure bearing layer to the tensile load bearing layer is defined as α _e ≦ α _f <α _a
It is desirable to set <α _b <α _c <α _d .

Next, the steel wire density of the tensile load-bearing layer (the steel wire spiral reinforcing layers 13a and 13b) is generally set to more than 90% and less than 95% for the conventional high-pressure hose. The high pressure hose 1a in the embodiment of the present invention is set at 70% to 90%.

That is, when the steel wire density is set to 70% or less, the steel wire is liable to be cut when the hose base is mounted, and when the steel wire density is set to 90% or more, the bending force becomes large, and the reel force is increased. This is because it becomes difficult to wrap the tape, which may hinder use.

The thickness of the interlayer rubber layer 5b on the side of the tensile load-bearing layer (steel wire spiral reinforcing layers 13a, 13b) is adjusted to the internal pressure-bearing layer (steel wire spiral reinforcing layers 12a, 12b).
The thickness is set to be larger than the thickness of the interlayer rubber layer 5a on the (b, 12c, 12d) side.

That is, the high-pressure rubber hose 1a in the embodiment of the present invention is required to have flexibility for winding on a reel. In order to improve the flexibility, the thickness of the interlayer rubber may be increased. However, on the other hand, the outer diameter of the hose is increased, the pressure resistance is reduced, and the mass is increased.

Therefore, in the case of the high-pressure hose 1a in this embodiment, the thickness of the interlayer rubber layer 5a on the inner pressure bearing layer side is the same as the thickness of the interlayer rubber layer of the conventional general-purpose hose (0.2 m).
m), the interlayer rubber layer 5b on the tensile load bearing layer side
Is thicker than the inner pressure bearing layer side (for example, 0.6
mm) makes the hose easier to bend.

Further, in the case of the conventional steel wire braided reinforcing layer, there is a restriction that the steel wire diameter is 0.4 mm or less due to braiding, but in the embodiment of the present invention, the steel wire spiral reinforcing layer is used. Since it is configured, there is no restriction in processing, and therefore, a steel wire having a wire diameter of more than 0.4 mm in the tensile load bearing layer can be used. As a result, the tensile strength is increased, and breakage at the metal fitting end can be prevented.

Next, the experimental results of the reel wound high pressure hose of the present invention are shown in Tables 1 and 2 below.

The specifications of the high-pressure hose used in this experiment were as follows: inner diameter: 50.8 mm, outer diameter: 75 mm, steel wire diameter: 0.8 m
m, interlayer rubber (inner pressure bearing layer: 0.2 mm, tensile load bearing layer: 0.6 mm). W / S is steel wire (wire)
/ Spiral.

Table 1 below shows the case where the winding angle of the internal pressure-bearing layer and the braid angle or the winding angle of the tensile load-bearing layer of the reel-wound high-pressure hose were variously set. 2, Comparative Examples 1, 2, 3, and Conventional Example 1,
For 2, the breaking pressure, tensile breaking force, hose elongation,
It is a comparison of bending force.

[0030]

[Table 1]

In Table 1, the bending force is in the order of Comparative Example 1> Comparative Example 3> Example 1> Example 2> Comparative Example 2 depending on the winding angle of the tensile load bearing layer. Things.

The reason why Conventional Example 2 (general-purpose hose) has a larger bending force than Examples 1, 2 and Comparative Example 2 is as follows.
This is because the thickness of the interlayer rubber between W / S and 5 W / S, 5 W / S and 6 W / S is thinner than that of Examples 1, 2 and Comparative Example 2. That is, the thickness of the interlayer rubber of Conventional Example 2 is 0.2 mm, and the thickness of the other hoses is 0.6 mm.

Table 2 below shows an experiment in which the winding angle of the internal pressure-bearing layer and the winding angle of the tensile load-bearing layer of the reel-wound high-pressure hose were fixed and the thickness of the interlayer rubber was changed. An example is shown.

[0034]

[Table 2]

In Table 2 above, in Comparative Example 2,
The reason why the bending force is smaller than in Examples 1 and 2 is that the thickness of the interlayer rubber of the tensile load bearing layer is large.

[0036]

As described above, in the present invention, at least two layers on the inner rubber layer side of the steel wire spiral reinforcing layer are formed as internal pressure bearing layers, and at least two layers on the outer periphery thereof are formed as tensile load bearing layers. However, since the winding angle of the tensile load-bearing layer is set smaller than the winding angle of the internal pressure-bearing layer, it is possible to withstand high pressure and has a large tensile strength, which effectively prevents damage at the metal fitting end. This has the effect that a high-pressure hose with high flexibility can be prevented.

[Brief description of the drawings]

FIG. 1 is a partially cutaway front view showing a reinforcing structure of a reel wound high pressure hose embodying the present invention.

FIG. 2 is a partially cutaway front view showing a conventional general-purpose high-pressure hose reinforcing structure.

FIG. 3 is a partially cutaway front view showing a conventional high-pressure hose reinforcing structure.

FIG. 4 is a partially cutaway front view of a conventional high-pressure hose having a steel wire braided reinforcing layer.

FIG. 5 is a partially cutaway front view of a conventional high-pressure hose provided with a steel wire braid reinforcement layer and a yarn braid reinforcement layer.

FIG. 6 is a partially enlarged front view of a high-pressure rubber hose equipped with a conventional fitting.

FIG. 7 is a schematic diagram when the winding angle of the tensile load bearing layer is set smaller than the winding angle of the internal pressure bearing layer.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 High-pressure rubber hose 2 Inner rubber layer 3 Center cloth 4 Outer rubber layer 5 Interlayer rubber layer 7a, 7b, 7c, 7d, 7e, 7f Steel wire spiral reinforcing layer 8a, 8b, 8c, 8d Steel wire spiral reinforcing layer 9 Steel wire braid Layers 10a, 10b, 10c Steel wire braided layers 11a, 11b Steel wire braided layers 11c Thread braided layers 12a, 12b, 12c, 12d Steel wire spiral reinforcement layers 13a, 13b Steel wire spiral reinforcement layers α _{a to} α _d Steel wire winding Angle 20 Metal fitting 20a Metal fitting terminal

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) 3H111 AA02 BA03 BA11 CB07 CB14 CB29 CC07 CC18 CC20 DA07 DA26 DB12 DB19 4F100 AB03D AB03E AN00A AN00B AN00C BA05 BA10A BA10B BA13 BA22 DA11 DD31 DH00D DH00E EH51E90K13 GB23 YY00D YY00E

Claims (5)

[Claims] 1. A high-pressure rubber hose comprising a plurality of steel wire spiral reinforcing layers interposed between an inner rubber layer and an outer rubber layer via an interlayer rubber layer, wherein the inner surface of the steel wire spiral reinforcing layer is provided. Two or more layers on the rubber layer side are used as an internal pressure bearing layer, and at least two or more layers on the outer periphery are configured as a tensile load bearing layer, and the winding angle of the tensile load bearing layer is determined by winding the inner pressure bearing layer. High-pressure rubber hose set smaller than the angle. 2. The high-pressure rubber hose according to claim 1, wherein the inner pressure-bearing layer and the tensile load-bearing layer are two or more even layers. 3. A winding angle of the tensile load-bearing layer,
90 to 103 smaller than the minimum winding angle of the inner pressure bearing layer
The high-pressure rubber hose according to claim 1 or 2, which is set to °. 4. The steel wire density of said tensile load bearing layer is 70
4. The high-pressure rubber hose according to claim 1, wherein the high-pressure rubber hose is set to 90%. 5. The method according to claim 1, wherein the thickness of the interlayer rubber layer on the tensile load-bearing layer side is set to be larger than the thickness of the interlayer rubber layer on the internal pressure-bearing layer side. High pressure rubber hose.