JP4882253B2 - High pressure rubber hose - Google Patents

Description

  The present invention relates to a high-pressure rubber hose, and more particularly, to a high-pressure rubber hose that can improve durability by preventing contact between reinforcing layers and is excellent in preventing metal fittings from coming off.

  A high-pressure rubber hose is generally configured by winding a plurality of reinforcing layers made of wires or the like in a spiral shape with an intermediate rubber layer sandwiched between an inner rubber layer and an outer rubber layer. This intermediate rubber layer prevents the reinforcing layers from contacting each other, and suppresses fatigue breakage of the wire resulting from this contact, thereby ensuring the durability of the high-pressure hose.

  However, when the high-pressure rubber hose 1 is manufactured as shown in FIG. 3, the intermediate rubber layer 4 may not follow a predetermined thickness. If the thickness of the intermediate rubber layer 4 is not uniform, the intermediate rubber layer 4 cannot perform a sufficient function, and the pressure fluctuation of the fluid in which the reinforcing layers 5 circulate inside the inner rubber layer 2 at the thin portion C. There is a problem that the contact of the high-pressure rubber hose 1 cannot be ensured due to fatigue failure of the wire 6 due to contact.

  Further, when the metal fitting is caulked, the intermediate rubber layer 4 is easily deformed and it is difficult to firmly fix the metal fitting, and further improvement in the prevention of removal of the metal fitting is necessary.

  A hose in which a predetermined amount of short fibers is blended in an intermediate rubber layer has been proposed for the purpose of eliminating such a high-pressure rubber hose and improving durability (see Patent Document 1).

However, at the time of vulcanization when manufacturing a high pressure rubber hose, the short fibers flow together with the rubber of the intermediate rubber layer and flow out from the intermediate rubber layer to the gap of the wire of the reinforcing layer, so that a sufficient amount of short fibers are added to the intermediate rubber layer. However, there is a problem in that contact between the reinforcing layers may not be prevented and durability cannot be ensured. Further, the intermediate rubber layer from which the short fibers have flowed cannot sufficiently improve the metal fitting prevention property.
Japanese Patent Publication No. 3-81035

  An object of the present invention is to provide a high-pressure rubber hose that can improve durability by preventing contact between reinforcing layers and that is excellent in preventing metal fittings from coming off.

In order to achieve the above object, the high-pressure rubber hose of the present invention has a plurality of reinforcing layers formed by winding a wire in a spiral shape between an inner rubber layer and an outer rubber layer, and an intermediate between each reinforcing layer. In the high-pressure rubber hose provided with the rubber layer, only the innermost intermediate rubber layer among the intermediate rubber layers is inserted with a cloth layer knitted in a lattice shape, and the thickness of the intermediate rubber layer inserted with the cloth layer Is 0.05 mm or more and 0.5 mm or less, the gauge thickness of the cloth layer is 0.05 mm or more and 0.3 mm or less, and the unit mass is 10 g / m ² or more and 60 g / m ² or less. is there.
Another high-pressure rubber hose of the present invention has a plurality of reinforcing layers formed by winding a wire in a spiral shape between an inner rubber layer and an outer rubber layer, and an intermediate rubber layer is provided between each reinforcing layer. In the high pressure rubber hose, among the intermediate rubber layers, only the innermost intermediate rubber layer is inserted with a cloth layer knitted in a lattice shape, and the thickness of the intermediate rubber layer with the cloth layer interposed is 0.05 mm. 0.5 mm or less, the gauge thickness of the cloth layer is 0.05 mm or more and 0.3 mm or less, the unit mass is 10 g / m ² or more and 60 g / m ² or less, and the cloth layer is in the thickness direction in the intermediate rubber layer. It is biased to one side and is in contact with the wire constituting the reinforcing layer.

According to the high pressure rubber hose of the present invention, there are a plurality of reinforcing layers formed by winding a wire in a spiral shape between the inner rubber layer and the outer rubber layer, and an intermediate rubber layer is provided between each reinforcing layer. In the high-pressure rubber hose, the intermediate rubber layer has a structure in which only the innermost intermediate rubber layer is interlaced with a cloth layer knitted in a lattice shape. The contact between the reinforcing layers, which could not be made, can be prevented by the cloth layer.

  As a result, fatigue breakage of the reinforcing layer wire due to contact between the reinforcing layers can be suppressed, and the durability of the high-pressure rubber hose can be improved.

  In addition, the intermediate rubber layer with the cloth layer interposed has a higher modulus than the rubber-only intermediate rubber layer, is hard to deform when the metal fitting is tightened to the end of the hose, and the metal fitting can be firmly fixed. It is possible to make it difficult to remove the bracket.

Hereinafter, the high-pressure rubber hose of the present invention will be described based on the embodiments shown in the drawings. FIG. 1 is a partially cutaway view of a high-pressure rubber hose 1 according to a reference embodiment , and FIG. 2 illustrates a cross section of the high-pressure rubber hose 1.

  In this high pressure rubber hose 1, four reinforcing layers 5 in which wires 6 are wound spirally are laminated between an inner rubber layer 2 and an outer rubber layer 7, and an intermediate rubber is interposed between the reinforcing layers 5. Layer 4 is provided. A cloth layer 3 knitted in a lattice shape is inserted in the intermediate rubber layer 4 coaxially.

  The high-pressure rubber hose 1 is formed by, for example, coating a rubber member to be an inner rubber layer 2 on an iron mandrel as in a conventional manufacturing method, and sequentially winding a wire 6 to be a reinforcing layer 5 in a spiral shape around the outer periphery thereof. The process of coating the rubber member to be the intermediate rubber layer 4 is repeated, and finally the rubber member to be the outer rubber layer 7 is coated to form an intermediate product made of unvulcanized rubber, which is then vulcanized and manufactured. can do.

  In this production, the rubber layer may be coated on the outer periphery of the reinforcing layer 5 using a rubber member laminated on one side or both sides of the fabric layer 3 as a rubber member to be the intermediate rubber layer 4. When covering, a tape-like sheet with a predetermined width may be wound in a spiral at an angle, or a tape-like sheet with a predetermined width may be wound in parallel with the axial direction of the hose without an angle. it can.

  In the high-pressure rubber hose 1 having this structure, even when the thickness of the intermediate rubber layer 4 becomes nonuniform during manufacture, the fabric layer 3 can prevent the reinforcing layers 5 from contacting each other. Since the fabric layer 3 is wound as an integrated sheet unlike short fibers, it hardly flows with the rubber of the intermediate rubber layer 4 during vulcanization, and can be reliably inserted between the reinforcing layers 5.

  As a result, even if the pressure fluctuation of the fluid flowing through the inner surface rubber layer 2 is repeatedly received, the wire 6 of the reinforcing layer 5 can be prevented from coming into contact and being damaged by fatigue. Accordingly, the durability of the high pressure rubber hose 1 can be improved. It becomes possible to improve.

  Furthermore, by inserting the fabric layer 3 into the intermediate rubber layer 4, the modulus of the intermediate rubber layer 4 is increased as compared with the case where only the rubber or short fibers are blended with the rubber. Therefore, when the metal fitting is crimped and fixed to the end of the high pressure rubber hose 1, the deformation of the intermediate rubber layer 4 is reduced, and the metal fitting can be firmly fixed to the high pressure rubber hose 1, and it is difficult to remove the metal fitting for a long time. It can be fixed.

The thickness of the intermediate rubber layer 4 interposed fabric layer 3, and 0.5mm or less. If the thickness exceeds 0.5 mm, the flexibility of the high-pressure rubber hose 1 is impaired and the transmission of pressure to the respective reinforcing layers 5 is hindered, resulting in problems that the reinforcing layers 5 cannot function sufficiently. is there. The lower limit of the thickness of the intermediate rubber layer 4 is 0.05 mm or more .

From the viewpoint of workability and flexibility of the high-pressure rubber hose 1 , the structure and material of the fabric layer 3 are made to have elasticity like a knitted fabric . Further, in order to prevent the rubber of the intermediate rubber layer 4 from entering the gap of the cloth layer 3 and to prevent the rubber and the cloth layer 3 from being separated from each other, the cloth layer 3 may have a certain amount of gap penetrating in the thickness direction. desirable. To ensure this gap, the unit mass of the gauge of the fabric layer 3 by 0.3mm or less and 60 g / m ² or less. These lower limits are defined by the material of the fabric layer 3, etc., but the gauge thickness is 0.05 mm or more and the unit mass is 10 g / m ² or more .

In this reference form , the cloth layer 3 is inserted in all the intermediate rubber layers 4, but the cloth layer 3 may be inserted in at least one intermediate rubber layer 4. In the present invention, the cloth layer 3 is inserted only into the innermost rubber layer 4 which is easily affected by the pressure fluctuation of the fluid circulating inside the inner rubber layer 2, while suppressing an increase in cost. The effect can be increased.

  The cloth layer 3 is inserted in the middle of the thickness of the intermediate rubber layer 4, but is not limited to this, and may be biased to one side in the thickness direction, and is in contact with the wire 6 of the reinforcing layer 5. Also good. That is, at the time of manufacturing the hose, as the rubber member of the intermediate rubber layer 4, one obtained by laminating rubber on one side of the cloth layer 3 or one obtained by laminating rubber on both sides of the cloth layer 3 can be used.

With a 4S / W spiral wire structure as shown in FIG. 1, the reinforcing layer has a wire diameter of 0.6 mm, the rubber of the inner rubber layer is a blend of SBR and NBR, and the rubber of the outer rubber layer is blended of CR and SBR. As a common condition that the rubber and the size were the same, only the specifications of the intermediate rubber layer between the reinforcing layers were changed to three as shown in Table 1 ( reference example , comparative examples 1 and 2), Performance was evaluated. The evaluation results are shown in Table 1. The evaluation items are the contact degree of the reinforcing layer, the impulse resistance, and the metal fitting prevention property.

The rubber of the intermediate rubber layer is CR for all three types, and the intermediate rubber layer of Comparative Example 2 is a mixture of 20% by mass of 6 nylon short fibers (6 mm in length) in the intermediate rubber layer of Comparative Example 1. is there. In addition, the intermediate rubber layer of the reference example is obtained by inserting a 6 nylon knitted fabric layer (gauge thickness of 0.20 mm, unit mass of 20 g / m ² ) into the intermediate rubber layer of Comparative Example 1.

[Reinforcement layer contact degree]
The inside of the manufactured high pressure rubber hose is inspected to show how many contact portions between the reinforcing layers (wires) exist due to non-uniformity of the intermediate rubber layer within a range of 10 m in length.

[Impulse resistance]
This evaluation is carried out in accordance with the impact pressure test specified in JIS B 8360, and the pressure is 34.5 MPa × 133% with a trapezoidal wave with a cycle of 1.17 Hz using oil at a temperature of 100 ° C. on a high pressure rubber hose. And the number of impulses until the hose was broken was measured, and the measurement result of Comparative Example 1 was indicated as 100, which was displayed as an index. The larger the value, the better the durability against repeated internal pressure.

[Metal fitting prevention]
A metal fitting was attached to the end of the high-pressure rubber hose at a predetermined tightening rate, and the pull-out resistance of the metal fitting was measured with a tensile tester. A slightly inferior case is indicated by a triangle, a good case is indicated by a circle, and a very good case is indicated by a double circle.

From these results, the high-pressure rubber hose of the reference example has a lower contact degree of the reinforcing layer than that of Comparative Examples 1 and 2 (no contact portion), and has excellent impulse resistance, and can prevent damage due to the contact of the reinforcing layer. It was confirmed that it was excellent in durability.

  It was also confirmed that the metal fitting prevention property can be improved more than Comparative Examples 1 and 2 by the cloth layer.

It is the side view partly cut open which illustrates the high pressure rubber hose of the reference form of the present invention. It is a cross-sectional view which illustrates the high pressure rubber hose of the reference form of this invention. It is a cross-sectional view which shows the state which the reinforcement layer is contacting in the conventional high pressure rubber hose.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 High pressure rubber hose 2 Internal rubber layer 3 Cloth layer 4 Intermediate rubber layer 5 Reinforcement layer 6 Wire 7 External rubber layer

Claims (2)

In the high pressure rubber hose having a plurality of reinforcing layers formed by winding a wire in a spiral shape between an inner rubber layer and an outer rubber layer, and providing an intermediate rubber layer between the respective reinforcing layers, the intermediate rubber layer Among them, only the innermost intermediate rubber layer is inserted with a cloth layer knitted in a lattice shape, and the thickness of the intermediate rubber layer inserted with the cloth layer is 0.05 mm or more and 0.5 mm or less, A high-pressure rubber hose characterized by having a gauge thickness of the fabric layer of 0.05 mm or more and 0.3 mm or less and a unit mass of 10 g / m ² or more and 60 g / m ² or less. In the high pressure rubber hose having a plurality of reinforcing layers formed by winding a wire in a spiral shape between an inner rubber layer and an outer rubber layer, and providing an intermediate rubber layer between the respective reinforcing layers, the intermediate rubber layer Among them, only the innermost intermediate rubber layer is inserted with a cloth layer knitted in a lattice shape, and the thickness of the intermediate rubber layer inserted with the cloth layer is 0.05 mm or more and 0.5 mm or less, The gauge thickness of the fabric layer is 0.05 mm or more and 0.3 mm or less, the unit mass is 10 g / m ² or more and 60 g / m ² or less, and the fabric layer is arranged in one direction in the thickness direction in the intermediate rubber layer, A high pressure rubber hose which is in contact with a wire constituting a reinforcing layer.

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