JPH10252955A - Refrigerant hose - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the flexibility of a hose while maintaining the durability of the hose in a multiple-layer refrigerant hose 1 having a resin layer 5 as an innermost layer. SOLUTION: A refrigerant hose 1 has a multi-layer structure including a first rubber layer 2, a reinforcing layer 3 made of a metal wire, a second rubber layer 4, and a resin layer 5 as an innermost layer from the outside to the inside. The resin layer 5 is made of an aromatic polyamide-based synthetic resin, has a spiral bellows shape, and has the same elasticity as each of the outer rubber layers.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a durable and flexible refrigerant hose comprising a multi-layer having a resin layer as an innermost layer, and is particularly suitable for use in a refrigeration cycle of a car air conditioner. .

[0002]

2. Description of the Related Art A refrigerant hose of this type is generally used in a refrigeration cycle or the like, and connects between various devices to allow the refrigerant to flow. The refrigerant hose is disposed on a route bent in accordance with the arrangement of each device, and is repeatedly subjected to bending stress due to vibration or the like from each device. For this reason, a structure having durability and flexibility is required.

FIG. 6 shows a structure of a refrigerant hose for a car air conditioner refrigeration cycle, which is generally used at present. The hose 11 has multiple layers. The layer structure is such that the first rubber layer 1 extends from the outside to the inside of the hose 11.
2, a reinforcing layer 13, a second rubber layer 14, and a resin layer 15 each made of a resin material (PET, aramid, etc.) and a metal wire, and the adjacent layers are bonded to each other with an adhesive.

Here, the two rubber layers 12 and 14 mainly secure the flexibility of the hose, and the reinforcing layer 13 mainly secures the strength of the hose. The resin layer 15 has a function of preventing leakage of the refrigerant flowing through the hose. This effect utilizes the property that resin has lower refrigerant permeability than rubber due to differences in molecular density and the like. Refrigerant leakage is not preferable from the viewpoint of environmental protection (stopping global warming). By the way, the above hose 1
1 is a case where there is no resin layer 15, that is, a first rubber layer,
Refrigerant permeation can be suppressed to about 1/10 as compared with a hose consisting of only the three layers of the reinforcing layer and the second rubber layer.

[0005]

In the above-mentioned general refrigerant hose, the resin does not have elasticity comparable to that of rubber, and the flexibility of the resin layer is not sufficient. As a result, the flexibility of the entire hose is reduced and rebound against bending occurs.
The workability of assembling such as attaching / detaching a hose to a device or arranging a hose in an arrangement route is deteriorated.

To solve the above problems, the innermost resin layer may be simply eliminated or the resin layer may be made thinner. However, such a measure is not desirable in view of the above-described prevention of refrigerant leakage. According to the study by the present inventors, the bonding surface between the second rubber layer and the resin layer in the above-mentioned general refrigerant hose is easily peeled off when subjected to large vibration or tension, and the possibility of hose clogging may occur. It became clear that there was. In view of the above, it is an object of the present invention to improve the flexibility of a hose while maintaining the durability of the hose in a multilayer hose having a resin layer as an innermost layer.

[0007]

Means for Solving the Problems The present inventors have paid attention to the fact that the above-mentioned lack of flexibility and peeling of the resin layer are caused by a difference in expansion and contraction performance between the rubber layer and the resin layer. The object is achieved by making the resin layer have the same elasticity as the rubber layer by changing the shape. That is, according to the first aspect of the present invention, at least one reinforcing layer (3), a resin layer (5) as an innermost layer, and a rubber layer (4) as an outer layer of the resin layer (5) are provided. A hose (1) composed of multiple layers and through which a refrigerant flows,
The resin layer (5) has a bellows shape and has flexibility.

As a result, the resin layer (5) has the same expansion and contraction performance as the rubber layer (4) due to expansion and contraction of the bellows, so that the flexibility of the hose as a whole can be improved and
In the bonding surface between the rubber layer (4) and the resin layer (5), the difference in shrinkage between the rubber and the resin can be reduced. Therefore, the workability of assembling the hose can be improved, the peeling of the rubber layer (4) and the resin layer (5) due to vibration or the like can be prevented, and the durability of the hose can be improved.

The resin used for the resin layer (5), which is hardly permeated by the refrigerant, is an aromatic polyamide synthetic resin represented by 6-nylon or the like. According to a third aspect of the present invention, in addition to the configuration of the first or second aspect, the bellows shape of the resin layer (5) is spiral. Thereby, the resin layer (5) integrally molded by the mandrel as a molding die
By rotating along the spiral, the action of the male screw and the female screw is generated, and the mold can be easily released.

Here, if the size of the bellows is too large, the pressure loss of the refrigerant flowing through the hose becomes too large, and if the size of the bellows is too small, the expansion and contraction of the bellows becomes difficult to be exhibited. . According to the study of the present inventors, as in claim 4, the pitch (L) of the bellows is 0.05 to 5 mm.
It has been found that when the height (H) of the bellows is 0.05 to 5 mm, the pressure loss of the refrigerant is not adversely affected while the effect of claim 1 is more effectively achieved.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS. 1 and 2,
An embodiment in which the present invention is applied to a refrigerant hose used to connect each device of a car air conditioner refrigeration cycle will be described. FIG. 1A shows a refrigerant hose 1 according to the present embodiment.
FIG. 1B is a partially cutaway perspective view of FIG.
It is an enlarged view of A part of (a). FIG. 2 is a cross-sectional view of the refrigerant hose 1 in a direction parallel to the axis.

The refrigerant hose 1 has a multi-layer structure, and has a first layer structure from the outside to the inside of the refrigerant hose 1.
A rubber layer 2, a reinforcing layer 3, a second rubber layer 4, and a resin layer 5 as an innermost layer. And each adjacent layer is mutually adhere | attached with the adhesive agent. Here, the two rubber layers 2 and 4 (for example, thickness of 1.2 to 1.5 mm) are made of an elastic member such as synthetic rubber, and secure the flexibility of the hose against bending and the like. The reinforcing layer 3 is made of a metal wire or the like, and secures the strength of the hose against pulling and the like. Here, the metal wire of the reinforcing layer 3 is, for example, 2000 to 4000 denier (D, 1D).
Is about 1 gram / 9000 m).

The resin layer 5 is formed of a resin through which a refrigerant hardly permeates, for example, an aromatic polyamide synthetic resin such as 6-nylon. Its thickness is, for example, 1
It is 00 to 150 μm, and has a thickness that does not easily allow the refrigerant to permeate. FIG. 1B is an enlarged view of the resin layer 5 (portion A in FIG. 1A). The shape of the resin layer 5 is a bellows shape, and the unevenness of the bellows is spiral. Due to the expansion and contraction action of the bellows, even if the refrigerant hose 1 is bent or pulled, the innermost resin layer 5 can expand and contract without a load according to the expansion and contraction of the outer rubber layers 2 and 4.

According to the study of the present inventors, if the pitch L of the bellows is 0.05 to 5 mm and the height H of the bellows is 0.05 to 5 mm, the expansion and contraction action of the bellows is increased. It turned out to be effective. That is, the pitch L
If the height H is too small, the bellows will not expand and contract sufficiently. If the height H is too large, the pressure loss of the refrigerant in the hose will increase due to the resistance of the bellows. Therefore, the size of the bellows is preferably in the above range.

As shown in FIG. 2, the resin layer 5 is bonded at the portion of the bellows unevenness which is in contact with the second rubber layer 4 of the outer surface layer. 4, a gap 6 corresponding to the height H of the bellows is present. next,
As a method of manufacturing the refrigerant hose 1 having the above configuration, first, the resin layer 5 is molded by a shaft-shaped mold (mandrel) (not shown) corresponding to the bellows shape. Then, by rotating the formed resin layer 5 along the spiral shape, the mold is released by the action of the male screw and the female screw.

Subsequently, a sheet-like layer coated with an adhesive is wound around the resin layer 5 in the order of the second rubber layer 4, the reinforcing layer 3, and the first rubber layer, so that the refrigerant is formed. The hose 1 is completed. Here, the method of connecting the refrigerant hose 1 to each device of the car air conditioner refrigeration cycle is mainly performed by caulking. For example, by inserting a pipe on the device side into the refrigerant hose 1 and caulking the outer peripheral surface of the refrigerant hose 1 (the outer peripheral surface of the first rubber layer) via a thin metal layer such as aluminum or iron, the innermost layer is formed. The resin layer 5 is plastically deformed and bonded to the pipe.

Further, as another caulking example, there is one shown in FIGS. In FIG. 3, a coating 8 such as a rubber or an adhesive is wound around a pipe 7 on the device side, inserted into the refrigerant hose 1, and then connected by caulking as described above. In FIG. 4, the outer peripheral surface of the pipe 7 is in a relationship of a male screw and a female screw with respect to the resin layer 5, and the pipe 7 is screw-fitted to the refrigerant hose 1 and connected by caulking as described above.

According to this embodiment, the resin layer 5
Since the rubber hose 2 has the same elastic performance as the rubber layers 2 and 4 due to the expansion and contraction of the bellows, the bending flexibility of the refrigerant hose 1 as a whole can be improved. Therefore, compared to the general refrigerant hose (see FIG. 6) described in the section of the related art, the repulsion against bending is weakened, so that the assembling workability for the worker can be improved. In addition, since the difference in shrinkage between the rubber and the resin can be reduced at the bonding surface between the second rubber layer 4 and the resin layer 5, peeling of the rubber and the resin due to bending or vibration can be prevented, and the durability of the hose is improved. it can.

Further, according to the present embodiment, since the bellows are formed in a spiral shape, the mold release at the time of molding is easy, and an excessive force is not required at the time of mold release. Can be prevented from being damaged and whitening. (Other Embodiments) In the above embodiment, the gap 6 corresponding to the height H of the bellows was present at the non-adhesion portion between the resin layer 5 and the second rubber layer 4. As described above, a configuration in which the rubber layer enters the gap may be adopted. Even with this configuration, the above-described effects of improving the flexibility and durability of the refrigerant hose can be realized. In addition, the second
The rubber portion of the rubber layer 4 and the resin layer 5 may or may not be bonded.

Since each of the above-described embodiments has durability against vibration as well as bending as described above, it can be used, for example, for a refrigerant hose of a car air conditioner which is susceptible to vibration from a vehicle or the like. it can. Among them, it is particularly suitable for use as a refrigerant hose connected to a device that receives a lot of vibration such as a compressor. In each of the above embodiments,
The present invention can be applied to not only a refrigerant hose of a car air conditioner refrigeration cycle but also a refrigerant hose of an engine heat pump which is easily affected by vibration from an engine or the like. That is, the application of the refrigerant hose to which the present invention is applied is not particularly limited to a refrigeration cycle for a car air conditioner.

In the above embodiments, the reinforcing layer is one layer, but may be two or more layers.

[Brief description of the drawings]

FIG. 1A is a partially cutaway perspective view of a refrigerant hose according to an embodiment of the present invention, and FIG. 1B is a partially enlarged view of FIG.

FIG. 2 is a sectional view in the axial direction of the hose of FIG. 1;

FIG. 3 is a cross-sectional view showing one connection method of the refrigerant hose of the embodiment.

FIG. 4 is a sectional view showing another connection method of the refrigerant hose of the embodiment.

FIG. 5 is a sectional view in the hose axis direction of a refrigerant hose according to another embodiment of the present invention.

FIG. 6A is a perspective view of a general refrigerant hose with a part cut away, and FIG. 6B is a cross-sectional view in the hose axial direction of FIG.

[Explanation of symbols]

1 ... Refrigerant hose, 3 ... Reinforcing layer, 4 ... Second rubber layer, 5 ... Resin layer, L ... Bellows pitch, H ... Bellows height.

Claims (4)

[Claims] An inner layer comprising at least one reinforcing layer (3), a resin layer (5) as an innermost layer, and a rubber layer (4) as an outer surface layer of the resin layer (5). A hose through which the refrigerant flows, wherein the resin layer (5) has a bellows shape and has flexibility. 2. The refrigerant hose according to claim 1, wherein the resin layer (5) is made of an aromatic polyamide-based synthetic resin. 3. The refrigerant hose according to claim 1, wherein the bellows shape of the resin layer (5) is spiral. 4. In the resin layer (5), the bellows pitch (L) is 0.05 to 5 mm, and the bellows height (H)
Is between 0.05 and 5 mm, the refrigerant hose according to any one of claims 1 to 3.