JP2018100726A - Hydraulic pressure brake hose - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hydraulic pressure brake hose having a structure that can prevent a first reinforcement yarn layer and a second reinforcement yarn layer from shifting in an axial direction relatively without an intermediate rubber layer.SOLUTION: A hydraulic pressure brake hose 100 includes: an inner surface rubber layer 1; a first reinforcement yarn layer 2 with a blade knitting structure; a second reinforcement yarn layer 3 with a blade knitting structure; and an outer surface rubber layer 4 in this order from the inside. Part (rubber 1a) of the inner surface rubber layer 1 adheres to an outer peripheral surface of the first reinforcement yarn layer 2 while sticking out therefrom.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a hydraulic brake hose having a reinforcing yarn layer, and more particularly to a hydraulic brake hose that is suitably used as a hydraulic brake hose.

  Examples of hoses having a reinforcing yarn layer include those described in Patent Documents 1 and 2. The hose described in Patent Document 1 is, for example, a refrigerant transport hose, and its reinforcing layers (inner reinforcing layer and outer reinforcing layer) are reinforcing yarn layers having a spiral winding structure. The reinforcing yarn layer having a spiral wound structure is formed by winding a reinforcing yarn in one direction around the outer peripheral surface of the reinforcing yarn layer inside.

  Here, the refrigerant transport hose used in a vehicle or the like is required to have a pressure resistance of about 3.5 MPa, for example. On the other hand, a hydraulic brake hose used in a vehicle or the like is required to have a pressure resistance performance of about 25 MPa, for example. Moreover, the hydraulic brake hose used for a vehicle etc. is a hose with a smaller diameter than the refrigerant transport hose from the viewpoint of the arrangement space.

  Therefore, in the hydraulic brake hose, a reinforcing yarn layer having a spiral winding structure is not adopted as the reinforcing yarn layer, and a reinforcing yarn layer having a blade knitting structure is adopted as the reinforcing yarn layer. This is because the pressure resistance of the spiral wound structure reinforcing yarn layer is lower than the pressure resistance of the braided knitting structure reinforcing yarn layer. And in the hydraulic brake hose, when it is a reinforcing thread layer of spiral winding structure, it is necessary to provide a multilayer of reinforcing thread layer of spiral winding structure to ensure its pressure resistance performance, turn into. Further, when the hose has a small diameter, the pressure resistance performance of the hose cannot be satisfied.

  Therefore, the hydraulic brake hose, like the hose described in Patent Document 2, has an inner rubber layer, a first reinforcing yarn layer having a blade knitting structure, an intermediate rubber layer, a second reinforcing yarn layer having a blade knitting structure, and an outer rubber layer. In general, the hose has a five-layer structure in this order from the inside.

JP2013-242000A Japanese Patent Laid-Open No. 10-122444

  Usually, a metal fitting is attached to the end of the hydraulic brake hose. When the metal fitting is attached (fastened) to the end portion of the hydraulic brake hose, the first reinforcing yarn layer and the second reinforcing yarn layer are compressed from the circumferential direction of the hose, and thus are extended in the axial direction of the hose. . Then, the intermediate rubber layer provided between the first reinforcing thread layer and the second reinforcing thread layer has a tendency that the first reinforcing thread layer and the second reinforcing thread layer are relatively extended in the axial direction and are displaced. It is for preventing. In addition, when the first reinforcing yarn layer and the second reinforcing yarn layer are relatively displaced in the axial direction, oil leakage occurs from a portion where the metal fitting is attached.

  Here, the present inventors examined whether the intermediate rubber layer could be eliminated with respect to the hydraulic brake hose as described above. If the intermediate rubber layer can be eliminated, the hydraulic brake hose can be manufactured with fewer steps than before, and the hydraulic brake hose can be made thinner than before.

  That is, an object of the present invention is to provide a hydraulic brake hose having a structure capable of preventing the first reinforcing yarn layer and the second reinforcing yarn layer from being relatively displaced in the axial direction even without an intermediate rubber layer. is there.

  The hydraulic brake hose according to the present invention has an inner rubber layer, a first reinforcing yarn layer having a blade knitted structure, a second reinforcing yarn layer having a blade knitted structure, and an outer rubber layer in this order from the inner side. A part of the inner rubber layer protrudes and adheres to the outer peripheral surface of the reinforcing yarn layer.

  In the present invention, the first reinforcing yarn layer and the second reinforcing yarn layer are brought into close contact with a part of the inner rubber layer protruding from the outer peripheral surface of the first reinforcing yarn layer. Thereby, even if there is no intermediate rubber layer, it is prevented that the first reinforcing yarn layer and the second reinforcing yarn layer are relatively shifted in the axial direction.

1 is a partially cutaway perspective view of a hydraulic brake hose according to an embodiment of the present invention. FIG. 2 is a partial development view (schematic diagram) of the first reinforcing yarn layer shown in FIG. 1 before vulcanization treatment. FIG. 2 is a partial development view (schematic diagram) of the first reinforcing yarn layer shown in FIG. 1 after vulcanization treatment.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

(Configuration of hydraulic brake hose)
As shown in FIG. 1, a hydraulic brake hose 100 (hydraulic brake hose) according to an embodiment of the present invention includes, from the inside, an inner rubber layer 1, a first reinforcing yarn layer 2 having a blade knitting structure, and a blade knitting structure. The second reinforcing yarn layer 3 and the outer rubber layer 4 are provided. The inner space of the inner rubber layer 1 is filled with brake oil. A brake (not shown) is actuated by applying pressure to the brake oil. The hydraulic brake hose 100 is suitably used for a four-wheeled vehicle, for example.

  The inner rubber layer 1 is formed of an ethylene-propylene-diene rubber (EPDM) composition. The material of the inner rubber layer 1 is not limited to the EPDM composition. Examples of other materials for the inner rubber layer 1 include a styrene-butadiene rubber (SBR) composition. Further, a rubber composition obtained by blending EPDM and SBR may be used as a material for the inner rubber layer 1.

  The Mooney viscosity of the rubber composition constituting the inner rubber layer 1 is preferably 55 or more and 115 or less. The Mooney viscosity refers to the viscosity value of rubber before vulcanization (unvulcanized rubber) measured using a Mooney viscometer by a method specified in JIS K6300-1. That is, the Mooney viscosity of the rubber composition constituting the inner rubber layer 1 is the rubber before vulcanization of the rubber measured with a Mooney viscometer according to the method specified in JIS K6300-1 (unvulcanized rubber). ) Viscosity value (so-called ML [1 + 4] 100 ° C.).

  The first reinforcing yarn layer 2 is formed by braiding braided reinforcing yarns 11 made of polyvinyl alcohol (hereinafter referred to as PVA) fibers on the outer peripheral surface of the inner rubber layer 1. The material of the reinforcing yarn 11 is not limited to the PVA fiber. Examples of other materials of the reinforcing yarn 11 include polyester fibers, polyamide fibers, aramid fibers, glass fibers, and metal fibers.

  The blade knitting is a known knitting method, for example, knitting a plurality of reinforcing yarns 11 crossing each other on the same circumference from both directions of one direction and the other direction. The first reinforcing yarn layer 2 of this embodiment is a blade knitted with two reinforcing yarns 11 as a set.

  Further, the inclination angle of the braided reinforcing yarn 11 with respect to the axial direction of the hose, that is, the braid angle θ (see FIG. 2) is preferably 54 degrees 44 minutes or more. This angle of 54 degrees and 44 minutes is called a static angle.

  Here, as shown in FIGS. 1 and 3, a part of the rubber 1 a of the inner surface rubber layer 1 protrudes and adheres to the outer peripheral surface of the first reinforcing yarn layer 2 from the inner side. The rubber 1a is obtained by protruding a part of the inner rubber layer 1 from the mesh 12 of the reinforcing yarn 11 (see FIG. 2). The mesh 12 of the reinforcing yarn 11 is an adjacent reinforcing yarn 11a braided in one direction on the same circumference, and an adjacent reinforcing yarn crossed to these and braided in the other direction on the same circumference. A slight gap surrounded by 11b.

  Further, the ratio of the total area of the rubber 1a (inner rubber) that is a part of the inner rubber layer 1 that protrudes and adheres to the outer peripheral surface of the first reinforcing yarn layer 2 to the area of the outer peripheral surface of the first reinforcing yarn layer 2, That is, the total area ratio of the rubber 1a is preferably 5% or more and less than 100%. The total area of the rubber 1a sticking out and sticking out is the sum of the areas of the rubber 1a sticking out and sticking out at a plurality of places.

  What percentage of the outer peripheral surface of the first reinforcing yarn layer 2 is attached with the protruding rubber 1a that is part of the inner rubber layer 1 is determined by disassembling the hydraulic brake hose 100 after vulcanization, The outer peripheral surface of one reinforcing yarn layer 2 can be automatically measured as the total area ratio of the rubber 1a by, for example, camera photography and image processing.

  The second reinforcing yarn layer 3 is formed on the outer peripheral surface of the first reinforcing yarn layer 2 by braiding the reinforcing yarn 13 made of PVA fiber by blade knitting. The material of the reinforcing yarn 13 is not limited to the PVA fiber like the reinforcing yarn 11. Examples of other materials of the reinforcing yarn 13 include polyester fibers, polyamide fibers, aramid fibers, glass fibers, and metal fibers.

  Here, the presence ratio of the reinforcing yarn 11 per unit volume in the first reinforcing yarn layer 2 is preferably smaller than the existing ratio of the reinforcing yarn 13 per unit volume in the second reinforcing yarn layer 3. In other words, the first reinforcing yarn layer 2 is preferably “rougher” than the second reinforcing yarn layer 3. The presence ratio of the reinforcing yarns 11 and 13 per unit volume in the reinforcing yarn layers 2 and 3 is determined by the fineness, the number and the number of pieces of the reinforcing yarns 11 and 13 to be braided, and the diameter of the reinforcing yarn layers 2 and 3. .

  The second reinforcing yarn layer 3 is covered with an outer rubber layer 4. The outer rubber layer 4 is formed of an ethylene-propylene-diene rubber (EPDM) composition. The material of the outer rubber layer 4 is not limited to the EPDM composition. Examples of other materials of the outer rubber layer 4 include a chloroprene rubber (CR) composition. Further, a rubber composition obtained by blending EPDM and CR may be used as a material for the outer rubber layer 4.

(Manufacturing method of hydraulic brake hose)
An outer peripheral surface of a long mandrel (not shown) is covered with a tubular inner rubber layer 1 formed by an extruder. The reinforcing yarn 11 is braided on the outer peripheral surface of the inner rubber layer 1 coated on the mandrel while applying a predetermined tension. Here, as described above, the Mooney viscosity of the rubber composition constituting the inner rubber layer 1 is not limited, but is preferably 55 or more and 115 or less. In the process of braiding the reinforcing yarn 11 on the outer peripheral surface of the inner rubber layer 1 while applying a predetermined tension, the inner rubber layer 1 is crushed by the reinforcing yarn 11 and, to some extent, in the axial direction. Stretched. When the Mooney viscosity of the rubber composition constituting the inner rubber layer 1 is 55 or more and 115 or less, a rubber composition that is neither too hard nor too soft is selected. A part of the inner rubber layer 1 tends to protrude from the outer peripheral surface of the thread layer 2.

  On the other hand, when the Mooney viscosity of the rubber composition constituting the inner rubber layer 1 is less than 55, it is too soft and too squeezed in the process of blade knitting. Part of the rubber layer 1 is difficult to protrude. On the contrary, if the Mooney viscosity of the rubber composition constituting the inner rubber layer 1 is more than 115, it is too hard, and part of the inner rubber layer 1 is difficult to protrude in the vulcanization process performed later.

  The second reinforcing yarn layer 3 is formed by braiding the reinforcing yarn 13 while applying a predetermined tension to the outer peripheral surface of the first reinforcing yarn layer 2 formed by braiding the reinforcing yarn 11 with the blade. . The outer peripheral surface of the second reinforcing yarn layer 3 is covered with a tubular outer rubber layer 4 formed by an extruder. Thereafter, the hose composed of the unvulcanized inner rubber layer 1, the first reinforcing yarn layer 2, the second reinforcing yarn layer 3, and the unvulcanized outer rubber layer 4 is vulcanized. Thereby, the hydraulic brake hose 100 is completed.

  In the vulcanization process, a part of the inner rubber layer 1 protrudes from the outer peripheral surface of the first reinforcing yarn layer 2. Since the first reinforcing yarn layer 2 is formed by braiding the reinforcing yarn 11, the outer peripheral surface thereof is uneven. Similarly, since the second reinforcing yarn layer 3 is formed by braiding the reinforcing yarn 13, the inner peripheral surface thereof is uneven. The rubber 1a protruding from the inner rubber layer 1 between the first reinforcing yarn layer 2 and the second reinforcing yarn layer 3 enters the recesses in the outer peripheral surface of the mesh 12 and the first reinforcing yarn layer 2, and the second reinforcing yarn. The first reinforcing yarn layer 2 and the second reinforcing yarn layer 3 are brought into close contact (integrated) by entering also into the concave portion of the inner peripheral surface of the yarn layer 3. Thereby, the rubber 1a exhibits a close contact (integration) effect and a wedge effect. As a result, the first reinforcing yarn layer 2 and the second reinforcing yarn layer 3 are prevented from being relatively displaced in the axial direction.

  In addition, the convex part of the outer peripheral surface of the first reinforcing yarn layer 2 (the reinforcing yarn 11 positioned on the second reinforcing yarn layer 3 side of the braided reinforcing yarn 11) and the inner periphery of the second reinforcing yarn layer 3 The first reinforcing yarn layer 2 and the second reinforcing portion are in a portion where the convex portion of the surface (the reinforcing yarn 13 positioned on the first reinforcing yarn layer 2 side of the braided reinforcing yarn 13) is in contact with each other. Between the thread layer 3, the rubber 1 a protruding from the inner rubber layer 1 does not enter. In other words, since the protruding part of the inner rubber layer 1 does not adhere to the entire outer peripheral surface of the first reinforcing yarn layer 2, the total area ratio of the inner rubber that adheres is less than 100%. .

(Example)
Tables 1 and 2 show five examples of the hydraulic brake hose 100. In Examples 4 and 5, although oil leakage finally occurred from the portion where the bracket of the hydraulic brake hose 100 was attached, a part of the inner rubber layer 1 was formed on the outer peripheral surface of the first reinforcing yarn layer 2. It has been confirmed that the film protrudes and adheres and has sufficient pressure resistance and burst pressure performance.
In addition, the oil leakage test as to whether or not oil leakage occurred was evaluated as follows in accordance with JIS D2601 “Brake fluid compatibility”. After holding for 72 hours at 120 ° C. with the brake fluid filled inside, if there is no abnormality by applying a pressure of 27.6 MPa for 120 seconds, then a burst test was performed, and then the part where the bracket was attached The presence or absence of oil leakage from the pipe (including oil around the fastening part fitting) was confirmed.

(Action / Effect)
The hydraulic brake hose 100, which is an example of a hydraulic brake hose, includes an inner rubber layer 1, a first reinforcing yarn layer 2 having a blade knitting structure, a second reinforcing yarn layer 3 having a blade knitting structure, and an outer rubber layer 4. It has in this order from the inside. A part of the inner rubber layer 1 (rubber 1 a) protrudes and adheres to the outer peripheral surface of the first reinforcing yarn layer 2.

  According to this configuration, the first reinforcing yarn layer 2 and the second reinforcing yarn layer 3 are brought into close contact with the outer peripheral surface of the first reinforcing yarn layer 2 by a part of the protruding inner rubber layer 1 (rubber 1a). The rubber 1a exhibits an adhesion (integration) effect and a wedge effect, and the first reinforcing yarn layer 2 and the second reinforcing yarn layer 3 are prevented from being relatively displaced in the axial direction even without an intermediate rubber layer. Is done.

  Here, it is preferable that the existence ratio of the reinforcing yarn 11 per unit volume in the first reinforcing yarn layer 2 is smaller than the existence ratio of the reinforcing yarn 13 per unit volume in the second reinforcing yarn layer 3.

  According to this configuration, a part of the inner rubber layer 1 is relatively easy to pass through the first reinforcing yarn layer 2, but the second reinforcing yarn layer 3 is difficult to pass through. Thereby, the rubber 1a which exhibits the adhesion (integration) effect and the wedge effect can be present between the first reinforcing yarn layer 2 and the second reinforcing yarn layer 3 with a moderate total area ratio. Further, when a part of the inner rubber layer 1 passes through the second reinforcing yarn layer 3 and reaches the outer rubber layer 4, it becomes a hose with an abnormal appearance, but this can be prevented.

  The Mooney viscosity of the rubber constituting the inner rubber layer 1 is preferably 55 or more and 115 or less. According to this configuration, a part of the inner rubber layer 1 tends to protrude from the outer peripheral surface of the first reinforcing yarn layer 2.

  Further, the ratio of the total area of the inner rubber (rubber 1a) that protrudes and adheres to the outer peripheral surface of the first reinforcing yarn layer 2 with respect to the area of the outer peripheral surface of the first reinforcing yarn layer 2, that is, the total area ratio of the rubber 1a. It is preferably 5% or more and less than 100%. According to this configuration, it is possible to further prevent the first reinforcing yarn layer 2 and the second reinforcing yarn layer 3 from being relatively displaced in the axial direction.

(Modification)
The above embodiment can be modified as follows.
The presence ratio of the reinforcing yarn 11 per unit volume in the first reinforcing yarn layer 2 is not limited to being less than the existing ratio of the reinforcing yarn 13 per unit volume in the second reinforcing yarn layer 3. For example, the existence ratio of the reinforcement yarn 11 per unit volume in the first reinforcement yarn layer 2 and the existence ratio of the reinforcement yarn 13 per unit volume in the second reinforcement yarn layer 3 may be approximately the same.

  The Mooney viscosity of the rubber composition constituting the inner rubber layer 1 is not limited to 55 or more and 115 or less. Even if the Mooney viscosity is out of the above range, the inner rubber layer 1 partially protrudes and adheres to the outer peripheral surface of the first reinforcing yarn layer 2, and an effect of having sufficient pressure resistance and burst pressure performance is obtained.

  The protruding portion of the inner rubber layer 1 is not limited to a part of the outer peripheral surface of the first reinforcing yarn layer 2 that is 5% or more and less than 100%. Even if a part of the protruding inner rubber layer 1 is attached to a portion of the outer peripheral surface of the first reinforcing yarn layer 2 that is less than 5%, the first reinforcing yarn layer 2 and the second reinforcing yarn layer 3 are relatively Thus, the effect of preventing the axial displacement can be obtained.

  In addition, it is needless to say that various modifications can be made within a range that can be assumed by those skilled in the art.

1: inner rubber layer 1a: rubber protruding from inner rubber layer 1: first reinforcing thread layer 3: second reinforcing thread layer 4: outer rubber layer 11, 13: reinforcing thread 100: hydraulic brake hose (hydraulic brake hose )

Claims (4)

A hydraulic brake hose having an inner rubber layer, a first reinforcing yarn layer having a blade knitting structure, a second reinforcing yarn layer having a blade knitting structure, and an outer rubber layer in this order from the inside,
A hydraulic brake hose characterized in that a part of the inner rubber layer protrudes and adheres to the outer peripheral surface of the first reinforcing yarn layer. In the hydraulic brake hose according to claim 1,
The hydraulic brake hose according to claim 1, wherein a presence rate of the reinforcing yarn per unit volume in the first reinforcing yarn layer is smaller than a presence rate of the reinforcing yarn per unit volume in the second reinforcing yarn layer. The hydraulic brake hose according to claim 1 or 2,
A hydraulic brake hose characterized by having a Mooney viscosity of the rubber composition constituting the inner rubber layer of 55 or more and 115 or less. In the hydraulic brake hose according to any one of claims 1 to 3,
The ratio of the total area of the inner rubber that protrudes and adheres to the outer circumferential surface of the first reinforcing yarn layer to the area of the outer circumferential surface of the first reinforcing yarn layer is 5% or more and less than 100%. , Hydraulic brake hose.

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