JP2003097770A - Hose for cooling carbon dioxide gas - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hose for cooling carbon dioxide gas, which has constant low permeability corresponding to the temperature of carbon dioxide gas, and prevents deterioration of a cooling performance. SOLUTION: This hose for cooling carbon dioxide gas comprises an inner pipe 1, which is made of polyamide resin having lower permeability to carbon dioxide gas that flows in a pipe; a plurality of barrier layers 2, which are installed around the inner pipe 1 and are obtained by spirally winding barrier tapes 20 that are composed of a laminar element of a metallic foil and a resin film; a resin reinforced layer 3, which is installed around the barrier layer 2; and an outer pipe 4, which is coated around the resin reinforced layer 3 and made of a thermoplastic elastomer (TPE). The number of barrier layers 2 corresponding to the temperature of carbon dioxide gas are installed, so that the hose has constant low permeability corresponding to the temperature of carbon dioxide gas. The inner pipe 1 is formed of resin having low permeability to carbon dioxide gas, so as to prevent a fluid path from being narrowed due to retention of carbon dioxide in the barrier layer 2.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a home air conditioner,
Regarding a carbon dioxide cooling hose used for cooling car air conditioners, various showcases, etc., in particular, carbon dioxide cooling that has a certain low permeability depending on the temperature of carbon dioxide and can prevent deterioration of cooling performance. For hoses.

[0002]

2. Description of the Related Art In cooling hoses used for home air conditioners, car air conditioners, etc., the use of carbon dioxide as a substitute for CFCs has been studied from the viewpoint of preventing the destruction of the ozone layer by CFCs.

As such a conventional carbon dioxide cooling hose, for example, there is one shown in Japanese Patent Application Laid-Open No. 11-264488.

This carbon dioxide cooling hose has an inner rubber tube through which carbon dioxide flows, a barrier layer formed around the inner rubber tube, an intermediate rubber layer formed around the barrier layer, and an intermediate rubber. A reinforcing layer formed around the layer and a rubber outer tube formed around the reinforcing layer are provided. The barrier layer is formed by adhering a metal foil to the inner rubber tube and the intermediate rubber layer via an adhesive layer. The metal foil of the barrier layer can prevent carbon dioxide from permeating into the atmosphere through the intermediate rubber layer, the reinforcing layer and the rubber outer tube. Further, since the inner tube and the outer tube are made of rubber, they have excellent flexibility.

[0005]

However, according to the conventional hose for cooling carbon dioxide, since the barrier layer is a single layer,
When carbon dioxide having a molecular weight lower than that of chlorofluorocarbon is used as the refrigerant, the higher the temperature, the easier the permeation becomes. Also, since the barrier layer is adhered to the inner pipe, when the hose is bent, a large stress is applied to the metal foil of the barrier layer, causing unrecoverable plastic elongation or rupture, and the barrier function disappears. Sometimes. Also, since the inner tube is made of rubber, carbon dioxide gas is more likely to permeate it than resin, so carbon dioxide gas stays in the barrier layer and the inner tube collapses inside, narrowing the flow path and cooling performance. May decrease.

Accordingly, an object of the present invention is to provide a carbon dioxide cooling hose which has a certain low permeability depending on the temperature of carbon dioxide and can prevent the deterioration of cooling performance.

[0007]

In order to achieve the above object, the present invention provides an inner tube made of a resin having a low permeability to carbon dioxide flowing in the tube, and an inner tube formed on the outer periphery of the inner tube. A hose for cooling carbon dioxide, comprising a barrier layer having a number of layers according to the temperature of carbon dioxide, and an outer tube formed on the outer periphery of the barrier layer. According to the above configuration, by providing the number of barrier layers according to the temperature of the carbon dioxide gas, the barrier layer has a certain low permeability according to the temperature of the carbon dioxide gas. By forming the inner tube from a resin having low permeability to carbon dioxide, carbon dioxide is less likely to stay in the barrier layer.

[0008]

FIG. 1 shows a carbon dioxide cooling hose according to an embodiment of the present invention. This carbon dioxide cooling hose is an inner tube 1 made of a resin having low permeability to carbon dioxide flowing in the tube, and a barrier provided in the periphery of the inner tube 1 and having a number of layers according to the temperature of the carbon dioxide. Layer 2 (2 ₁ ,
2 ₂ , 2 ₃ ), a fiber reinforcing layer 3 provided around the barrier layer 2, and an outer tube 4 made of a thermoplastic elastomer (TPE) coated around the fiber reinforcing layer 3. ing.

The inner tube 1 may be made of polyamide resin such as 6 nylon, 11 nylon, 12 nylon, 46 nylon, 6-66 copolymer nylon, etc., but has a low permeability to carbon dioxide gas. If so, other resins may be used.

2A and 2B show cross sections of the barrier layer 2. The barrier layer 2 is a metal foil 2 having a thickness of 2 to 20 μm.
1. A barrier tape 20 made of a laminate in which 1 and a resin film 23 having a thickness of 10 to 30 μm are joined by an adhesive layer 22 and spirally wound at an overlapping rate of 10 to 50% of the tape width. is there. As the metal foil 21, for example, an aluminum foil can be used. Resin film 23
Is, for example, polyethylene terephthalate (PET),
Polyamide (PA), polyvinyl alcohol (PV
A), polyvinylidene chloride (PVDC), etc. can be used. The strength of the barrier tape 20 can be secured by using the resin film 23. Metal foil 2
1 and the resin film 23 are the temperature of the carbon dioxide gas refrigerant (150
It is adhered by the adhesive layer 22 so as not to peel even at (° C.). The combination of the metal foil 21 and the resin film 23 has at least one layer of the metal foil 21, and may be a combination of the metal foil 21 / resin film 23 as shown in FIG. 2 (a), or as shown in FIG. 2 (b). Thus, a combination of resin film 23 / metal foil 21 / resin film 23 or the like can be used. Note that an adhesive (for example, PVDC) may be applied or laminated on both sides or one side of the barrier layer 2. Further, each of the barrier layers 2 ₁ to 2 _3, all right-handed helical or may be wound in counterclockwise spiral, may be wound alternately in a right-handed spiral and the left-handed spiral.

According to the carbon dioxide cooling hose constructed as described above, since the barrier layer 2 having the number of layers corresponding to the temperature of the carbon dioxide is formed on the outer circumference of the inner pipe 1, the barrier layer 2 corresponding to the temperature of the carbon dioxide is formed. It is possible to secure a certain low permeability. Also,
Since the inner pipe 1 is made of a resin having low permeability to carbon dioxide, carbon dioxide does not easily leak to the barrier layer 2 and stay in the barrier layer 2 and the flow passage can be prevented from narrowing. It is possible to prevent the cooling performance from deteriorating. Further, since the inner tube 1 and the barrier layer 2 are not adhered to each other, even if the hose is bent, the metal foil 21 of the barrier layer 2 does not undergo plastic elongation, so that the barrier function can be ensured. Further, since the barrier layer 2 is formed by winding the barrier tape 20, the displacement between the inner tube 1 and the outer tube 4 can be absorbed when the hose is bent, and the flexibility can be ensured.

FIG. 3 shows the relationship between the temperature of carbon dioxide and the amount of permeation. As is clear from the figure, by providing the three barrier layers 2, the permeation amount of carbon dioxide gas can be significantly suppressed, and the permeation amount of carbon dioxide gas at 150 ° C. can be reduced to a practical level of 3%.
It can be g / 50 cm or less.

[0013]

As described above, according to the carbon dioxide cooling hose of the present invention, since the number of barrier layers corresponding to the temperature of carbon dioxide is formed on the outer circumference of the inner tube, the temperature of carbon dioxide is reduced. Has a certain low permeability. Further, since the inner pipe is formed of a resin having low permeability to carbon dioxide gas, it is possible to prevent carbon dioxide gas from staying in the barrier layer and prevent deterioration of cooling performance.

[Brief description of drawings]

FIG. 1 is a perspective view of essential parts showing a carbon dioxide cooling hose according to an embodiment of the present invention.

2A and 2B are cross-sectional views of a barrier layer.

FIG. 3 is a diagram showing the relationship between the temperature of carbon dioxide and the amount of permeation according to the number of barrier layers.

[Explanation of symbols]

1 Inner Tube 2, 2 ₁ , 2 ₂ , 2 ₃ Barrier Layer 3 Fiber Reinforcement Layer 4 Outer Tube 20 Barrier Tape 21 Metal Foil 22 Adhesive Layer 23 Resin Film

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Katsuhiro Aoyagi             Hitachi, 1-1 Sukegawa-cho, Hitachi City, Ibaraki Prefecture             Electric Wire Co., Ltd. Inside the electric wire factory (72) Inventor Tomoya Ishii             Hitachi, 1-1 Hidaka-cho, Hitachi City, Ibaraki Prefecture             Electric Cable Co., Ltd. F-term (reference) 3H111 AA02 BA01 BA15 CA03 CA08                       CA52 CB07 CB14 CB24 CB29                       CC03 DA26 DB11                 4F100 AB01B AB33B AK01A AK01C                       AK42C AK46A AK48 AL09                       AR00A AT00C BA03 BA04                       BA05 BA07 BA10A BA10C                       DA11 DC22B DC30B DG01                       EC18 EC182 GB31 JB16                       JD02 JD02A JD02B JD02D                       JD05E JK01 YY00B

Claims (7)

[Claims] 1. An inner tube made of a resin having a low permeability to carbon dioxide flowing in the tube, a barrier layer formed on the outer periphery of the inner tube and having a number of layers according to the temperature of the carbon dioxide, A hose for cooling carbon dioxide, comprising an outer tube formed on the outer periphery of the barrier layer. 2. The carbon dioxide cooling hose according to claim 1, wherein the resin is a polyamide resin. 3. The carbon dioxide cooling hose according to claim 1, wherein the barrier layer is formed with 3 to 5 layers of the barrier layer. 4. The carbon dioxide cooling hose according to claim 1, wherein the barrier layer is provided on the outer periphery of the inner tube without using an adhesive. 5. The hose for cooling carbon dioxide gas according to claim 1, wherein the barrier layer is provided with a barrier tape which is spirally wound around the outer circumference of the inner pipe at a predetermined overlapping ratio. 6. The carbon dioxide gas cooling hose according to claim 4, wherein the barrier tape is made of a laminate of a metal foil and a resin film. 7. The carbonic acid according to claim 6, wherein the metal foil is an aluminum foil having a thickness of 2 to 20 μm, and the resin film is a polyethylene terephthalate film having a thickness of 10 to 30 μm. Gas cooling hose.