U.S. patent application number 14/267473 was filed with the patent office on 2014-11-06 for rubber hose.
This patent application is currently assigned to Hitachi Metals, Ltd.. The applicant listed for this patent is Hitachi Metals, Ltd.. Invention is credited to Takafumi NONAKA, Tomonori SAITO, Tomonori SHIBATA.
Application Number | 20140326355 14/267473 |
Document ID | / |
Family ID | 51252486 |
Filed Date | 2014-11-06 |
United States Patent
Application |
20140326355 |
Kind Code |
A1 |
NONAKA; Takafumi ; et
al. |
November 6, 2014 |
RUBBER HOSE
Abstract
A rubber hose includes an inner rubber layer including a hollow
part, an first braided layer formed on the inner rubber layer by
braiding a plurality of first yarn materials, a middle rubber layer
formed on the first braided layer, a second braided layer formed on
the middle rubber layer by braiding a plurality of second yarn
materials, and an outer rubber layer formed on the second braided
layer. The first braided layer is formed by braiding the plurality
of first yarn materials including a vinylon fiber made by a dry
process such that the braided first yarn materials includes a braid
formed in a three-over, three-under pattern. The second braided
layer is formed by braiding the plurality of second yarn materials
including a vinylon fiber made by a wet process such that the
braided second yarn materials includes a braid formed in a
two-over, two-under pattern.
Inventors: |
NONAKA; Takafumi; (Bangkok,
TH) ; SAITO; Tomonori; (Hitachi, JP) ;
SHIBATA; Tomonori; (Hitachi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Hitachi Metals, Ltd. |
Tokyo |
|
JP |
|
|
Assignee: |
Hitachi Metals, Ltd.
Tokyo
JP
|
Family ID: |
51252486 |
Appl. No.: |
14/267473 |
Filed: |
May 1, 2014 |
Current U.S.
Class: |
138/126 |
Current CPC
Class: |
F16L 11/086 20130101;
B29L 2023/006 20130101; F16L 11/087 20130101; B29C 48/151 20190201;
B29D 23/00 20130101; B29C 48/21 20190201; B29K 2023/16 20130101;
B29C 48/0015 20190201; B29K 2029/04 20130101 |
Class at
Publication: |
138/126 |
International
Class: |
F16L 11/00 20060101
F16L011/00 |
Foreign Application Data
Date |
Code |
Application Number |
May 2, 2013 |
JP |
2013-096950 |
Claims
1. A rubber hose, comprising: an inner rubber layer comprising a
hollow part; a first braided layer formed on an outer periphery of
the inner rubber layer by braiding a plurality of first yarn
materials; a middle rubber layer formed on an outer periphery of
the first braided layer; a second braided layer formed on an outer
periphery of the middle rubber layer by braiding a plurality of
second yarn materials; and an outer rubber layer formed on an outer
periphery of the second braided layer, wherein the first braided
layer is formed by braiding the plurality of first yarn materials
comprising a vinylon fiber made by a dry process such that the
braided first yarn materials comprises a braid formed in a
three-over, three-under pattern, and wherein the second braided
layer is formed by braiding the plurality of second yarn materials
comprising a vinylon fiber made by a wet process such that the
braided second yarn materials comprises a braid formed in a
two-over, two-under pattern.
2. The rubber hose according to claim 1, wherein the first yarn
materials and the second yarn materials comprise a bundled yarn
with two or three wound yarns.
3. The rubber hose according to claim 1, wherein the inner rubber
layer and the outer rubber layer comprise EPDM.
Description
[0001] The present application is based on Japanese patent
application No.2013-096950 filed on May 2, 2013, the entire
contents of which are incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to a rubber hose such as a brake hose
etc.
[0004] 2. Description of the Related Art
[0005] A brake hose is extremely important to secure the safety of
the vehicles and is appointed in the important security parts.
[0006] JP-A-2005-180694 discloses a brake hose. The brake hose
disclosed in JP-A-2005-180694 comprises a first core hose layer
(tube) inside of which is filled with brake fluid, a first
reinforcing member layer provided on the outer periphery on the
first core hose layer, a middle hose layer provided on the outer
periphery on the first reinforcing member layer, a second
reinforcing member layer provided on the outer periphery of the
middle hose layer, and an outer hose layer provided on the outer
periphery of the second reinforcing member layer, wherein the first
reinforcing member layer is constructed by braiding reinforcing
yarns in a one-over, one-under pattern, and wherein the second
reinforcing member layer is constructed by braiding reinforcing
yarns in a three-over, three-under pattern.
[0007] The related arts may also include JP-A-2010-515002.
SUMMARY OF THE INVENTION
[0008] The brake hose is required to have a durability against the
hard mechanical stresses (i.e., durability against a shaking
movement) such as a bending, a steering change and a shaking caused
by the repeating motion of the vehicle steering wheel, and at the
same time required not to grow an expansion quantity in
pressurizing (low expansion performance) which is an expansion
quantity of a brake hose in applying pressure to brake liquid
filled in a hollow part of an inner hose layer.
[0009] However, there is a problem that the brake hose disclosed in
JP-A-2005-180694 does not provide a high durability against the
shaking movement and a low expansion performance.
[0010] It is an object of this invention to provide a rubber hose
that allows improvement in durability against a shaking movement
and low expansion performance.
[0011] (1) According to one embodiment of the invention, a rubber
hose comprises: [0012] an inner rubber layer comprising a hollow
part; [0013] a first braided layer formed on an outer periphery of
the inner rubber layer by braiding a plurality of first yarn
materials; [0014] a middle rubber layer formed on an outer
periphery of the first braided layer; [0015] a second braided layer
formed on an outer periphery of the middle rubber layer by braiding
a plurality of second yarn materials; and [0016] an outer rubber
layer formed on an outer periphery of the second braided layer,
[0017] wherein the first braided layer is formed by braiding the
plurality of first yarn materials comprising a vinylon fiber made
by a dry process such that the braided first yarn materials
comprises a braid formed in a three-over, three-under pattern, and
[0018] wherein the second braided layer is formed by braiding the
plurality of second yarn materials comprising a vinylon fiber made
by a wet process such that the braided second yarn materials
comprises a braid formed in a two-over, two-under pattern.
[0019] In the above embodiment (1) of the invention, the following
modifications and changes can be made. [0020] (i) The first yarn
materials and the second yarn materials comprise a bundled yarn
with two or three wound yarns. [0021] (ii) The inner rubber layer
and the outer rubber layer comprise EPDM.
EFFECTS OF THE INVENTION
[0022] According to one embodiment of the invention, a rubber hose
can be provided that allows improvement in durability against a
shaking movement and low expansion performance.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] The preferred embodiments according to the invention will be
explained below referring to the drawings, wherein:
[0024] FIG. 1 is a total view schematically showing a rubber hose
according to an embodiment of this invention;
[0025] FIGS. 2A and 2B are views schematically showing the details
of the braided layers of a rubber hose according to an embodiment
of this invention, wherein FIG. 1A is a view schematically showing
the first braided layer (with a braid formed in a three-over,
three-under pattern), and FIG. 1B is a view schematically showing
the second braided layer (with a braid formed in a two-over,
two-under); and
[0026] FIG. 3 is a view schematically explaining the examination of
bending durability of a rubber hose according to an embodiment of
this invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0027] The preferred embodiment of this invention will be explained
below referring to the figures attached.
[0028] As shown in FIG. 1, a rubber hose 1 according to an
embodiment of this invention comprises an inner rubber layer 2
inside of which a hollow part is formed along the longitudinal
direction, a first braided layer 3 provided on the outer periphery
on the inner rubber layer 2 and formed by braiding the plural first
yarn materials, a middle rubber layer 4 provided on the outer
periphery on the first braided layer 3, a second braided layer 5
provided on the outer periphery on the middle rubber layer 4 and
formed by braiding the plural second yarn materials, and an outer
rubber layer 6 provided on the outer periphery on the second
braided layer 5.
[0029] It is preferable that the inner rubber layer 2 and the outer
rubber layer 6 is formed of ethylene propylene diene rubber (EPDM),
and other than the EPDM, chloroprene rubber (CR), natural rubber
(NR), styrene-butadiene rubber (SBR), isobutylene rubber (IIR), and
chlorosulfonated polyethylene rubber (CSM) are used depending on
the characteristics. Besides, a filler, a cross-linking agent, a
reinforcing agent, a plasticizer, a cross-linking assistant, an
activator, an anti scorching agent, and an oxidation inhibitor may
be property added to the rubbers, and a vulcanizing agent, a
vulcanization accelerator, and a vulcanization assistant, etc, may
be added to a vulcanized rubber as needed.
[0030] In addition, the inner rubber layer 2 and the outer rubber
layer 6 made of EPDM are excellent in heat resistance, cold
resistance, ozone resistance, and light resistance caused by the
molecular structure of EPDM. The EPDM is most suitable as a stuff
of a brake hose because it is a low polarity polymer and at a low
risk of corroding metal fitting parts.
[0031] FIG. 2A shows the details of the first braided layer 3, and
the first braided layer 3 is constructed by braiding plural first
yarn materials 7, which are each formed of vinylon fibers
manufactured by a dry process, in a three-over, three-under
pattern. The first yarn materials 7 shown in FIG. 2A are each
formed of a bundled yarn with three wound yarns 7a, 7b, and 7c
bundled collectively, but it may be formed of a bundled yarn with
two wound yarns bundled collectively. The first yarn materials 7
are braided such that vertical first yarn materials 7 and
horizontal first yarn materials 7 are crossed each other so that at
the crossing part three units of the vertical or horizontal first
yarn materials 7 pass over the horizontal or vertical first yarn
materials 7 respectively (3-over), and that at the next crossing
part three units of the horizontal or vertical first yarn materials
7 pass under the vertical or horizontal first yarn materials 7
respectively (3-under).
[0032] FIG. 2B shows the details of the second braided layer 5, and
the second braided layer 5 is constructed by braiding plural second
yarn materials 8, which are each formed of vinylon fibers
manufactured by a wet process, in a two-over, two-under pattern.
The second yarn materials 8 shown in FIG. 2B are each formed of a
bundled yarn with three wound yarns 8a, 8b, and 8c bundled
collectively, but it may be formed of a bundled yarn with two yarns
bundled collectively. The second yarn materials 8 are braided such
that the vertical second yarn materials 8 and the horizontal second
yarn materials 8 are crossed each other so that at the crossing
part two units of the vertical or horizontal second yarn materials
8 pass over the horizontal or vertical second yarn materials 8
respectively (2-over) and at the next crossing part two units of
the horizontal or vertical second yarn materials 8 pass under the
vertical or horizontal second yarn materials 8 respectively
(2-under).
[0033] The three wound yarns 7a, 7b, and 7c composing the first
yarn material 7 of the first braided layer 3 are formed a vinylon
fiber manufactured by the dry process, more specifically, a vinylon
fiber fibrosed by the process that a vinylon polymer dissolved in a
volatile spinning solution is spat from a nozzle and simultaneously
heated so as to vaporize the volatile spinning solution. The three
wound yarns 8a, 8b, and 8c composing the second yarn material 8 of
the second braided layer 5 are formed of a vinylon fiber
manufactured by the wet process, more specifically, a vinylon fiber
fibrosed by the process that a vinylon polymer dissolved in the
spinning solution is spat from a nozzle in a liquid. The vinylon
fiber manufactured by the wet process can have a high tensile
strength and a small elongation to a load because the wet process
enables to control the molecular orientation of vinylon polymer in
a high degree by extruding the spinning solution to a liquid
(solidification liquid). Thus, the vinylon fiber manufactured by
the wet process can exhibit a low expansion performance and a high
tensile strength of a hose.
[0034] Reducing a total fineness (or total fiber fineness/denier)
in addition to applying the three-over, three-under braid pattern
to the first braided layer 3 and applying the vinylon fibers
manufactured by the wet process to the second braided layer 5
having only a small influence on the durability can provide a hose
having a further low expansion. This is because the tension applied
to the yarn is varied by (or proportional to) the inner pressure
multiplied by the perimeter or cross section. Therefore the tension
applied to one yarn at the same inner diameter decreases according
as the outer diameter decreases. Thereby, the elongation of the
yarn decreases and results in a small expansion of the hose.
Meanwhile, even if the total fineness is reduced, a reduction in
the tensile strength can be minimized by using the vinylon fibers
with a high tensile strength manufactured by the wet process.
[0035] As mentioned above, the increment of manufacturing cost can
be lowered by reducing the total fineness even when the costly
vinylon fibers manufactured by the wet process are used.
Examples
[0036] Example 1 as a preferred embodiment of this invention will
be described below in conjunction with Comparative Examples 1 to
3.
[0037] The materials of the hoses in Example 1 and Comparative
Examples 1 to 3, and the experiment results of the hoses are shown
in Table 1 below.
TABLE-US-00001 TABLE 1 Comparative Comparative Comparative Example
1 Example 1 Example 2 Example 3 Specification of Inner rubber Kind
of rubber EPDM EPDM EPDM EPDM hose layer First braided Kind of yarn
Dry process Dry process Dry process Wet process layer vinylon
vinylon vinylon vinylon Elongation rate 0.55 0.55 0.55 0.50 of a
yarn at load of 10 N (%) Total fineness 52,800 52,800 52,800 52,800
Braiding method 3-over, 3-under 2-over, 2-under 2-over, 2-under
3-over, 3-under Middle Kind of rubber EPDM EPDM EPDM EPDM rubber
layer Second Kind of yarn Wet process- Dry process- Dry process-
Wet process- braided layer vinylon vinylon vinylon vinylon
Elongation rate 0.50 0.55 0.55 0.50 of a yarn at load of 10 N (%)
Total fineness 63,840 95,760 63,840 95,760 Braiding method 2-over,
2-under 2-over, 2-under 2-over, 2-under 2-over, 2-under Outer
rubber Kind of rubber EPDM EPDM EPDM EPDM layer Performance of hose
Expansion 0.087 0.129 0.119 0.095 quantity (ml/305 mm) Number of
700,000 800,000 700,000 200,000 durability (times) Tensile strength
2,800 2,800 2,600 3,000
[0038] The hose of Example 1 comprising the materials described in
Table 1 was manufactured such that the inner rubber layer is first
extruded on the mandrel, the first braided layer is then formed on
the outer periphery of the inner rubber layer by braiding, the
middle rubber layer is then formed on the outer periphery of the
first braided layer, the second braided layer is then formed on the
outer periphery of the middle rubber layer by braiding, the outer
rubber layer is then formed on the outer periphery of the second
braided layer by extrusion, and the vulcanization is finally
conducted to obtain the hose. The hoses of Comparative Example 1 to
3 comprising the materials described in Table 1 were manufactured
by the same process as Example 1.
[0039] The examinations of expansion quantity, durability, and
tensile strength were carried out for the hoses manufactured by the
processes, after cutting the hoses to the prescribed lengths.
[0040] The examination of the durability was carried out by the
following method by using a bending testing machine (model number:
V270-2) from Sum Electro Mechanics Co., LTD. A brake fluid (JIS
K2233) is filled in a hollow part of a brake hose, the hose is
attached to a system for repeatedly applying pressures of 0 MPa and
9.8 MPa thereto, and the atmosphere temperature is adjusted to
100.degree. C. Then, as shown in FIG. 3, fixing one end of the
hose, bending strokes of .+-.40 mm at a frequency of 1.66 Hz are
applied to the other end of the hose. Herein, the number of bending
strokes until the hose is damaged is defined as the number of
durability. Meanwhile, the hose was attached at the time of the
examination in a layout to cause simultaneously the bending and
twisting of the hose.
[0041] The elongation rate of the yarn at a load of 10 N is an
index assuming that a hose is pressurized at 10 MPa, and multiple
wound yarns of 1330 dtex in fineness were used for the measurement
thereof.
[0042] From the results shown in Table 1, it is proved by comparing
Comparative
[0043] Example 1 and Comparative Example 2 that a reduction in the
total fineness of the second braided layer causes a reduction in
the expansion quantity, and by comparing Comparative Example 1 with
Comparative Example 3 that a low elongation rate of a yarn at a
load of 10 N causes a low expansion quantity, but results in a low
durability.
[0044] In comparing Example 1 and Comparative Examples 1 to 3 shown
in Table 1, it is proved that the tensile strength tends to
increase when the elongation rate of a yarn at a load of 10 N is
small and the total fineness is large.
[0045] Thus the hose of Example 1 as an embodiment of this
invention is such a hose that can controls the reduction of the
tensile strength to a minimum in spite of the reduction of the
total fineness, and has the ultralow expansion quantity performance
not more than 0.090 ml/305 mm (0.087 ml/305 mm in Example 1), and
keeps the durability not less than 600,000 times (700,000 times in
Example 1).
[0046] As described above, this invention can realize the ultralow
expansion quantity performance by using the three-over, three-under
braid pattern to the braiding method of the first braiding layer.
Besides, this invention can achieve the further low expansion
quantity performance and minimize the reduction of the tensile
strength in spite of the reduction of the total fineness by using
the vinylon fibers manufactured by the wet process to the second
braided layer having only a small influence on the durability and
by reducing the median diameter of the braided layer by reducing
the total fineness.
[0047] Furthermore, with regard to the facility for manufacturing
the hoses of the invention, only the length of deflector which
controls the method of braiding the first braided layer is needed
to be changed. Therefore, the manufacturing cost of the hose can be
prevented from increasing. Thus the invention is extremely
practical.
[0048] Although this invention has been described with respect to
the specific embodiments and examples, this invention should not be
restricted within the range described above and it should be noted
that this invention would be variously changeable within the scope
of the description of the claims.
* * * * *