JPH11201340A - High pressure rubber hose - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rubber hose that ensures a high internal pressure and has an excellent flexibility. SOLUTION: This rubber hose comprises a first layer that a first reinforcement layer 11 and a second reinforcement layer 12 are provided between an inner rubber tube 10 and an outer rubber tube 14. The first reinforcement layer 11 is formed by a first layer that reinforcement lines are spirally wound on the inner rubber tube 10 in one direction, and further a second layer that reinforcement lines are spirally wound on the first layer in the reversed direction. The second reinforcement layer 12 is formed by a braided layer that reinforcement lines are incorporated each other.

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, and more particularly to a high-pressure rubber hose suitable for a brake hose used in an automobile brake device.

[0002]

2. Description of the Related Art In a hydraulic brake in a brake device of an automobile, the depressing force of a brake pedal is changed to a hydraulic pressure by a master cylinder and transmitted to each wheel cylinder through a brake hose. Conventional brake hoses consist of a rubber tube and a reinforcing layer. That is, the brake hose is made of ethylene-propylene-diene rubber (EPDM) and styrene-butadiene rubber (SB
R), a first reinforcing layer using vinylon yarn as a reinforcing yarn, natural rubber (NR), EPD
M, butyl rubber (IIR), etc., an intermediate rubber layer, a second reinforcing layer using vinylon yarn, and an outer rubber tube made of EPDM and chloroprene rubber (CR) having good ozone resistance. . The first reinforcing layer and the second
The reinforcing layer is a braided layer formed by a blade or a spirally wound wound layer. The wound layer is formed by winding a second layer on the first layer of reinforcing yarn wound in one direction so as to be opposite to each other.

[0003] The brake hose having the above structure is usually manufactured as follows. That is, an inner rubber tube is extruded around the outer periphery of a long resin mandrel prepared in advance, and the first reinforcing layer is formed as a braided layer or formed as a wound layer on the outer surface of the inner rubber tube. Next, the intermediate rubber layer is extruded on the outer peripheral surface of the first reinforcing layer by an extruder, or the intermediate rubber layer is formed while winding a long rubber tape. When the rubber tape is wound, the second reinforcing layer is formed by braid braiding while winding the rubber tape, or is formed by spiral winding. Further, an outer rubber tube is extruded on the outer periphery of the second reinforcing layer. These rubber hoses are vulcanized, and after vulcanization, a mandrel is extracted, cut into a predetermined length, and used.

[0004]

However, the conventional brake hose has the following problems. When the reinforcing layer is a braided layer, the reinforcing yarns are woven together, so that the reinforcing yarns easily move when subjected to internal pressure. The brake hose is repeatedly subjected to internal pressure due to the depressing force of the brake pedal during traveling, but the braided braid is easy to move and has excellent flexibility and durability, but it easily expands and maintains constant braking performance There was a problem that it was not possible. On the other hand, when the reinforcing layer is a wound layer, the reinforcing yarns are wound without gaps, and the second layer is wound in the opposite direction so that the reinforcing yarns are difficult to move. I have. The brake hose receives internal pressure during running and is constantly rocked by tire bounce and rebound. For this reason, the wound layer does not easily expand even when subjected to an internal pressure, and does not reduce the braking performance. However, since the wound layer is inflexible, the reinforcing yarn is apt to be broken and has poor durability.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a brake hose which does not reduce the braking performance even when subjected to high internal pressure or repeated bending, and has excellent durability. Aim.

[0006]

The present invention has the following configuration to achieve the above object. That is, the high-pressure rubber hose according to the present invention is provided with a first reinforcing layer and a second reinforcing layer between the inner rubber tube and the outer rubber tube, and the first reinforcing layer is provided with a reinforcing thread on the inner rubber tube in one direction. A first layer wound in a spiral shape, and a reinforcing layer formed on the first layer by a second layer in which a reinforcing yarn is spirally wound in the opposite direction;
The second reinforcing layer is formed of a braided layer in which reinforcing yarns are woven together. It is preferable that the inner rubber tube and the outer rubber tube are formed of ethylene / propylene / diene rubber, and an intermediate rubber layer of chloroprene rubber is provided between the first reinforcing layer and the second reinforcing layer.

[0007]

The wound layer of the first reinforcing layer suppresses expansion due to internal pressure,
The braided layer of the second reinforcing layer acts to absorb the tensile strain generated when the hose is bent, so that a high-performance rubber hose having a small amount of expansion and excellent in durability can be obtained.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments of the present invention will be described. First, FIG. 1 shows a side view of a brake hose according to the present invention with a part cut away, and FIG. 2 shows an enlarged sectional view. In the figure, 10 is EPD in which the brake fluid is hardly permeated
M is an inner rubber tube, 11 is a first reinforcing layer, which is a wound layer in which vinylon yarn is spirally wound around the outer peripheral surface of the inner rubber tube 10, and 12 is a second braided layer formed by weaving vinylon yarn. The reinforcing layer 13 is composed of the first reinforcing layer 11 and the second reinforcing layer 1.
An intermediate rubber layer 14 is provided between the two and bonded to each other, and 14 is an outer rubber tube coated with EPDM having very good ozone resistance.

The inner rubber tube 11 has a thickness of 0.6 to 1 mm.
The intermediate rubber layer 13 is formed by applying a rubber paste. The rubber glue is more excellent in brake fluid permeability than the EPDM forming the inner rubber tube 10, and is preferably prepared from CR having polarity. Outer rubber tube 1
The thickness of 4 is preferably 0.8 to 1.2 mm.

The first reinforcing layer 11, which is a wound layer, forms a first layer 11a by winding vinylon yarn without any gap in a state where the yarns are aligned in a direction opposite to, for example, clockwise. A vinylon yarn is wound on the opposite side of the first layer 11a in the opposite direction to the first layer, that is, clockwise, like the first layer 11a.
It is formed by forming the layer 11b. The second reinforcing layer 12 is formed by braiding with a normal braider.

In the present invention, the reason why the inner first reinforcing layer is a wound layer and the outer second reinforcing layer is a braided layer is as follows. That is, when an internal pressure is applied to the rubber hose, a tensile stress is generated in the hose, and the magnitude of the tensile stress becomes maximum inside the hose. On the other hand, when the hose is bent, tensile strain is generated outside the hose, and compressive strain is generated inside the hose. The magnitude of each strain is maximum on the outer peripheral surface and the inner peripheral surface of the hose. For this reason, the inner peripheral surface of the hose requires pressure resistance,
Rather, the outer peripheral surface requires flexibility.

It can be seen that the first reinforcement layer controls the expansion due to the internal pressure, and that the second reinforcement layer controls the flexibility.
Therefore, in the present invention, in order to suppress expansion due to internal pressure, the spiral wound layer is used as the first reinforcing layer, and the braided layer that is easy to move is used as the second reinforcing layer. By such a combination of configurations, it is possible to provide a brake hose having little change in expansion and excellent durability.

[0013]

Next, specific examples of the brake hose according to the present invention will be described together with comparative examples. The brake hose has an inner diameter of 3.4 mm, an outer diameter of 10.5 mm, and an inner rubber tube 1
0 has a thickness of 0.8 mm and a reinforcing yarn of vinylon yarn is 1200.
The thickness of the denier outer rubber tube 14 was 1.0 mm. In Comparative Example 1, the first reinforcing layer 11 and the second reinforcing layer 12 were both braided layers, and in Comparative Example 2, the first reinforcing layer 11 and the second reinforcing layer 1 were used.
In Comparative Example 3, the first reinforcing layer 11 was a braided layer, and the second reinforcing layer 12 was a wound layer.
About the Example and the comparative example, the expansion amount test and the whip test were performed, respectively. These tests are based on JIS D2601
(Automotive hydraulic brake rubber hose).
The test results are as shown in Table 1.

[0014]

[Table 1]

As is clear from Table 1, in the examples, not only the amount of expansion was small, but also the durability was excellent, and a high performance brake rubber hose was obtained as compared with the comparative example.

[0016]

As described above in detail, in the present invention, since the inner first reinforcing layer is a wound layer and the second reinforcing layer is a braided layer, a rubber hose which is strong against internal pressure and flexible. Thus, a brake hose having excellent durability under repeated pressure swings can be obtained.

[Brief description of the drawings]

FIG. 1 is a perspective view of a partially cut-away brake hose according to the present invention.

FIG. 2 is an enlarged sectional view of the same.

[Explanation of symbols]

 Reference Signs List 10 inner rubber tube 11 first reinforcing layer 12 second reinforcing layer 13 intermediate rubber layer 14 outer rubber tube

Claims (2)

[Claims] 1. A first reinforcing layer and a second reinforcing layer are provided between an inner rubber tube and an outer rubber tube, and the first reinforcing layer spirally winds a reinforcing thread in one direction on the inner rubber tube. A first layer formed on the first layer, and a second layer formed by winding a reinforcing yarn spirally in the opposite direction on the first layer, and a second reinforcing layer is a braided layer for knitting the reinforcing yarn with each other. A high-pressure rubber hose characterized by being formed by: 2. The inner rubber tube and the outer rubber tube are made of ethylene.
2. The high-pressure rubber hose according to claim 1, wherein an intermediate rubber layer made of chloroprene rubber is provided between the first reinforcing layer and the second reinforcing layer.