JPH11230429A - Structure of high pressure hose - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the structure of a noble high pressure hose to prevent the occurrence of a twist during pressurization of a spiral hose. SOLUTION: This high pressure hose comprises an inner surface layer 1; fiber reinforcement layers 2 and 4 making a pair in a direction corresponding to the outerperiphery thereof and having a plurality of fibers spirally wound; and an outer surface layer 5 to cover the reinforcement layers. Provided a pitch of the lower layer fiber reinforcement layer 2 of the fiber reinforcement layers, making a pair, is P1 , a winding angle is θ2 , a pitch of an upper layer fiber reinforcement layer 4 is P2 , and a winding angle is θ2 , formulas of P2 >P2 and θ1 <θ2 are established, and an average of two angles is set to 51-57 deg..

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the structure of a high-pressure hose such as a hydraulic cleaning hose and a hydraulic hose.

[0002]

2. Description of the Related Art In general, a high-pressure hose is a spiral hose which reinforces a pair of two layers in which a plurality of fibers are wound around an inner rubber layer in opposite directions clockwise and counterclockwise as one unit. Has been adopted. Such a spiral hose is
It is wound by using equipment having a two-deck turntable called a spiral machine. The inner layer is extruded to a predetermined size on a mandrel, and a pair of the above-mentioned spiral machine is formed on the outer periphery by a spiral machine. Are wound at the same time, and if necessary, four layers may be wound at the same time.

Therefore, in general, it is needless to say that the reinforcing fibers wound simultaneously around the outer periphery of the inner rubber layer on the mandrel are wound at the same pitch, and each deck of the spiral machine rotates in the opposite direction. . Normally, a rubber sheet for bonding is inserted between the layers. In some cases, this is not used in a hose for relatively low pressure. Depending on the application, the rubber sheet is selectively inserted between the necessary fiber reinforced layers. Sometimes. In addition, it is common to further extrude and coat the outer cover rubber in addition to the reinforcement as described above. The outside of the outer cover rubber is coated with a lead mold or a resin mold and then heated and vulcanized. The way to do it is taken.

[0004] In the spiral hose obtained by the above manufacturing method, the winding pitch of the fiber reinforcing layer is the same.
The winding angle of the upper fiber reinforcing layer having a larger outer diameter than that of the lower fiber reinforcing layer is larger with respect to the inner rubber layer.

However, in this kind of spiral hose, when pressurized, that is, when the hose is used for use and the fluid passes through the inner rubber layer, the wound fiber reinforcing layer is formed by the hose shaft. Attempts to move in a direction that results in a stationary angle of 54 degrees 44 minutes relative to the direction. For this reason, in a normal spiral hose, the average angle of the fiber winding angle of the reinforcing layer is set to 53 to 55.
It has been practiced to determine the winding pitch in degrees. The same applies to the case where there are four fiber reinforcement layers.

[0006]

However, since the winding pitch of the fiber reinforcing layer is the same in a normal spiral hose, the difference in the winding angle differs depending on the thickness of the fiber and the presence or absence of an adhesive sheet. However, the difference is still about 2 to 4 degrees. In a hose having such a structure, when a fluid is passed through the inner rubber layer and pressurized, the hose is inevitably twisted. In the case of a relatively short hose such as used as a hydraulic piping part, the hose wound in a coil shape may be distorted by pressurization. There has been a problem that the hose is twisted and the life is shortened, or abrasion occurs due to contact with peripheral components.

The present invention provides a novel high-pressure hose structure for preventing such a spiral hose from being twisted during pressurization.

[0008]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and the gist of the present invention is to form an inner surface layer and a plurality of fibers in pairs in a direction facing the outer periphery. A high-pressure hose composed of a spirally wound fiber reinforcement layer and an outer surface layer covering the reinforcement layer, wherein the pitch P ₁ of the lower fiber reinforcement layer of the pair of fiber reinforcement layers and the winding angle θ
₁ , if the pitch P ₂ of the upper fiber reinforcing layer and the winding angle θ ₂ are P ₁ > P ₂ and θ ₁ <θ ₂ , and the average of both angles is 51 to 57 degrees, preferably 52 to 57 degrees. This is related to the structure of a high-pressure hose of 56 degrees.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In a conventional high-pressure spiral hose having the above-described structure, it is generally inevitable that when it is pressurized, it will be twisted in the winding direction of the upper fiber reinforcing layer. This is because, at the time of pressurization, the lower fiber reinforced layer first bears the pressure, so that the lower fiber reinforced layer is twisted in a direction in which the lower fiber reinforced layer spreads, that is, the lower fiber reinforced layer is in a direction opposite to the winding direction (unwinding side). When the lower fiber reinforcement layer expands sufficiently due to pressure, the pressure is then transmitted to the upper fiber reinforcement layer, where the upper fiber reinforcement layer also bears the pressure and acts to reduce the twist of the hose.

The present invention solves the problem by analyzing the behavior of each fiber reinforcing layer of such a hose. In this case, the winding angle of the upper fiber reinforcing layer with respect to the inner surface layer is made larger in advance than that of the prior art. The pressure load on the lower and upper fiber reinforcing layers during pressurization is equalized, thereby preventing the hose from being twisted during pressurization.

In the case where the whole hose has a plurality of pairs of fiber reinforcing layers, at least one pair of the fiber reinforcing layers exhibits the effect. It is needless to say that an adhesive rubber sheet layer can be inserted between the pair of fiber reinforced layers, and if the adhesive rubber sheet layer is not inserted, the pair of fiber reinforced layers contact each other. It may be.

As the reinforcing fibers used in the present invention, vinylon, polyester, aramid, nylon and the like can be used. Needless to say, the number of yarns can be appropriately changed. Needless to say, the number of yarns to be threaded is 16 in Table 1 described later, but in this case, the number of yarns to be driven can be changed to about ± 4.

The relationship between the winding angle θ ₁ of the lower fiber reinforcing layer and the winding angle θ ₂ of the upper fiber reinforcing layer is θ ₁ <θ ₂ , and the average value of both is 51 to 57 degrees. In order to almost completely prevent the torsion at the time of pressurization, the difference between the winding angles may be 5 degrees or more. It is also found that the change in the length of the hose is determined by the average value of the winding angles of the lower and upper fiber reinforced layers, which makes it possible to adjust the length.

[0014]

EXAMPLES The high-pressure spiral hose of the present invention will be further described below with reference to examples. FIG. 1 shows the structure of a high-pressure spiral hose. Reference numeral 1 denotes an inner rubber layer, 2 denotes a lower fiber reinforcing layer, 3 denotes an adhesive rubber sheet, 4 denotes an upper fiber reinforcing layer, and 5 denotes an outer rubber layer. It is. In the conventional high-pressure spiral hose, the spiral winding pitch of the lower fiber reinforcing layer 2 is P ₁ , the winding angle is θ ₁ , the spiral winding pitch of the upper fiber reinforcing layer 4 is P ₂ , and the spiral winding pitch is P ₂ . Angle
When _2, in _{P 1> P 2, θ 1} = θ 2 relationship. However, in the high pressure spiral hose of the present invention, P
₁ > P ₂ and a structure wound in a relationship of θ ₁ <θ ₂ .

Hereinafter, a comparative test was conducted on the structure of each fiber reinforcing layer and the torsion of the hose using the high-pressure spiral hose shown in the figure. The high-pressure spiral hose has an inner diameter of 12.7 mm, an outer diameter of 23.8 mm, and a reinforcing fiber of 540.
Fibers of each layer were obtained from 16 x 0 denier vinylon yarns.

In the test, the amount of twist was shown by cutting the hose to 1 m, fixing one end of the hose, and twisting the other end when pressurized. Also, change of hose length,
Burst pressure was measured by the method shown in JIS K 6331.
Table 1 shows the structures of the high pressure hoses tested and the test results.

[0017]

[Table 1]

[0018]

As shown in Table 1, it can be seen that the hose of the present invention has less torsion when pressurized and the burst pressure is improved as compared with the conventional hose. In addition, it was found that there was no problem in the practical use of the hose length change in any of the examples.

[Brief description of the drawings]

FIG. 1 is a partial anatomical view showing a high-pressure spiral hose.

[Explanation of symbols]

1 ‥‥ inner rubber layer, 2 ‥‥ lower fiber reinforcement layer, 3 ‥‥ adhesive rubber sheet, 4 ‥‥ upper fiber reinforcement layer, 5 ‥‥ outer rubber layer, P ₁ス パ イ spiral winding of lower fiber reinforcement layer Attached pitch, P ₂ピ ッ チ Spiral winding pitch of upper fiber reinforcing layer, θ ₁ス パ イ Spiral winding angle of lower fiber reinforcing layer, θ ₂ス パ イ Spiral winding angle of upper fiber reinforcing layer.

Claims (4)

[Claims] 1. A high-pressure hose comprising: an inner surface layer; a fiber reinforcing layer in which a plurality of fibers are spirally wound in pairs in a direction facing the outer periphery; and an outer surface layer covering the reinforcing layer. If the pitch P ₁ of the lower fiber reinforcement layer and the winding angle θ _{1 of} the pair of fiber reinforcement layers, the pitch P ₂ of the upper fiber reinforcement layer, and the winding angle θ ₂ , P ₁ > P ₂ , θ ₁ < θ ₂ and
And a high-pressure hose structure in which the average of both angles is 51 to 57 degrees. 2. The high pressure hose structure according to claim 1, wherein an adhesive rubber sheet layer is inserted between said pair of fiber reinforced layers. 3. The high pressure hose structure of claim 1 wherein said pair of fiber reinforced layers are in contact with each other. 4. The high pressure hose structure according to claim 1, wherein at least one pair of the fiber reinforcing layers is present.