JPH09112757A - Flexible tube and refrigerating machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flexible tube which is effective to prevent excessive deformation of a bellows and suppress damage of the bellows, even in the case of used under strong vibration or large relative displacement environment. SOLUTION: A flexible tube 1 comprises a corrugated bellows 2 alternatingly continuing crown parts 20 and valley parts 21 along the axial length direction in a cross section and a cylindrical braided body 6 arranged outside of the bellows 2. The cylindrical braided body 6 which is formed by braiding a plurality of nonmetal wire rods into a cylinder shape is displaced in the internal diameter direction with application of tensile force. The internal wall face of the cylindrical braided body 6 which is subjected to the tensile force in the axial length direction touches the tops 20a of the crown parts 20 of the bellows internally with application of the tensile force.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a flexible tube and a refrigerator. INDUSTRIAL APPLICABILITY The flexible tube according to the present invention can be used in places where vibration is severe or where relative displacement frequently occurs. The flexible tube according to the present invention, for example, in a refrigerator in which a compression unit and a low temperature generation unit are separated (for example, Gifode McMahon, Solvay refrigerator, pulse refrigerator, etc.), a compression unit and a low temperature generation unit. Can be used as piping to connect

[0002]

2. Description of the Related Art As a conventional technique, there is known one having a cylindrical metal bellows having continuous peaks and valleys and a cylindrical braid covering the bellows (Swagelo).
Catalog MS-01-39 of company k). The braid is formed by spirally weaving strips made of stainless steel-based wire rods in one direction and in the opposite direction so as to pass through and cross each other. According to this, since the braid covers the bellows, it is advantageous to prevent the bellows from extending and meandering due to the pressure of the working fluid flowing inside the bellows.

As a conventional technique, as shown in FIG.
It is known that a bellows 800 having a cylindrical shape in which peaks 800a and valleys 800b are alternately continuous and a cushioning material 900 made of a gel-like or elastomer-like substance adhered to the valleys 800b of the bellows 800 are known. (Actual fair 5-3
1321). According to this publication, even when placed in an environment with severe vibration conditions, the cushioning function of the cushioning material 900 can absorb the vibration.

[0004]

However, according to the above-mentioned technique of Swagelok, when placed in an environment with severe vibration conditions, the bellows and the blade are relatively displaced relative to each other. As a result, the peaks of the bellows and the blade are easily rubbed and easily damaged. In some cases, the wall of the bellows has a damaged hole, and the airtightness of the bellows is reduced.

According to the technique shown in FIG. 12, the cushioning material 9 is used.
Numeral 00 is for sealing the valley portion 800b of the bellows 800 without any gap. Therefore, when the bellows 800 greatly expands and contracts or bends significantly, the pressure of the cushioning material 900 tends to locally become excessively high. It is considered that this is because there is no escape place for the cushioning material 900 because the cushioning material 900 fills the valleys 800b of the bellows 800 without any gap.

In such a case, a large stress concentration is likely to occur on the bellows 800. As a result, the bellows 800 may be damaged. The present invention has been made in view of the above circumstances, and the technical problems of claims 1 to 4 are advantageous in regulating excessive deformation of the bellows, and are used in an environment where vibration is severe or an environment where relative displacement is severe. Even in the case where the bellows is used, it is to provide a flexible tube which is advantageous in suppressing damage to the bellows.

The technical problem of claim 5 is advantageous in controlling excessive deformation of the bellows, and is also advantageous in suppressing damage to the bellows even when the bellows is used in an environment with severe vibration conditions. It is to provide a refrigerator equipped with a flexible tube.

[0008]

In order to solve the above-mentioned technical problem of the present invention, the following technical means are adopted. The flexible tube according to claim 1 is disposed on the outer side of the inner tube, the inner tube including at least a part of which has a corrugated bellows in which peaks and valleys are alternately continuous in a cross section along the axial direction. It is formed by braiding a large number of non-metallic wire rods in a tubular shape, and is composed of a tubular braid that is displaced in the inner diameter direction when tension is applied. Is added, and the inner wall surface of the tubular braid is inscribed at the top of the mountain portion of the bellows.

A flexible tube according to a second aspect of the present invention is the flexible tube according to the first aspect, wherein a tubular base to which at least one end of the inner pipe in the axial direction is connected, and a ring-shaped base provided on the outer peripheral surface of the base. And a fastening member, the end of the tubular braid is fixed to the outer peripheral surface of the die by the fastening member while being attached to the outer peripheral surface of the die.

A flexible tube according to a third aspect of the present invention is the flexible tube according to the second aspect, wherein the fastening member is made of the same material as the base. A flexible tube according to a fourth aspect of the present invention is the flexible tube according to the first aspect, including a tubular mouthpiece to which at least one end of the inner tube in the axial direction is connected by a welded portion, and a covering tube that covers the welded portion from the outside. It is characterized in that the end portion of the tubular braid is adhered to the outer peripheral surface of the covering cylinder and is not in contact with the welded portion.

According to a fifth aspect of the present invention, there is provided a refrigerator having a compression section for compressing a refrigerant and a low temperature generation section for expanding the refrigerant, and the low temperature generation section and the compression section are relatively displaced. And the flexible pipe described in the first paragraph are communicated with each other.

[0012]

According to the flexible tube of the first aspect, the tubular braid is a tubular braid of non-metallic wire rods. A tubular braid is generally a braid formed by spirally weaving in one direction and in the opposite direction so that a suitable number of long wire rods are aligned and the strips cross each other. Can be adopted. Resin can be adopted as the non-metallic wire material constituting the tubular braid, and for example, aramid fiber system, wholly aromatic polyester fiber system, and ultra-high degree of polymerization polyethylene fiber system can be adopted.

According to the flexible tube of the first aspect, since the tubular braid is tensioned in the axial direction of the tubular braid, the diameter of the tubular braid is reduced and the inner wall surface of the tubular braid is reduced. It is strongly inscribed on the top of the bellows mountain. Moreover, the contact area between the inner wall surface of the tubular braid and the top of the mountain portion of the bellows is increased. Therefore, the vibration and displacement of the ridges of the bellows are easily suppressed. Therefore, excessive deformation of the bellows is restricted.

According to the flexible tube of the second aspect, the end portion of the tubular braid is fixed to the outer peripheral surface of the die by the ring-shaped fastening member while being attached to the outer peripheral surface of the die. Therefore, it is advantageous to apply tension to the tubular braid in the axial direction thereof. According to the flexible tube of the third aspect, since the fastening member is made of the same material as the base, the thermal expansion coefficient and the thermal contraction rate of the base and the thermal expansion coefficient and the thermal contraction rate of the fastening member are brought close to each other. Or it is advantageous to make them the same.

Therefore, even when it is used in an environment where the temperature fluctuation is large, for example, when it is used in a refrigerator that lowers the temperature from a normal temperature range to a low temperature or an extremely low temperature (about several to several tens of K), The difference in thermal expansion and the difference in thermal contraction can be suppressed. Therefore, it is possible to suppress the loosening of the fastening strength of the fastening member due to the difference in thermal expansion and the difference in thermal contraction, and the fastening member satisfactorily fastens the base and thus the tubular braid.

Further, the inner tube provided with the bellows and the mouthpiece are often connected by welding. The welded part may have unevenness or sharpness. Therefore, when the tubular braid formed by weaving a non-metallic and flexible wire rod rubs the welded portion, the tubular braid is easily damaged. In this respect, according to the flexible tube of the fourth aspect, since the welded portion connecting the inner tube provided with the bellows and the mouthpiece is covered with the covering cylinder, the tubular braid directly contacts the welded portion having the mating damage. Can be prevented. Therefore, it is advantageous for ensuring the protection of the flexible tubular braid.

According to the refrigerator of the fifth aspect, the low temperature generating section and the compression section, which are relatively displaced, are connected by the flexible tube according to the first aspect. Even if the relative displacement occurs, since the inner wall surface of the tubular braid is in close contact with the top of the mountain portion of the bellows,
Excessive deformation of the bellows is suppressed, and excessive frictional sliding between the tubular braid and the bellows is suppressed.

[0018]

【Example】

(Embodiment 1) FIG. 1A shows a cross section of a flexible tube 1 according to the first embodiment, and FIG. 1B shows a cross section of a main part thereof. A bellows 2 that functions as an inner tube is provided. Bellows 2
In the section, the cross section along the axial direction has a wave shape in which the peaks 20 and the valleys 21 are alternately continuous.

The bellows 2 is thin and made of metal (for example, stainless steel, Hastelloy, Inconel). The wall thickness of the bellows 2 is about 0.1 to 0.4 μm, but the thickness is not limited to this. To both ends of the bellows 2 in the axial direction, metal bases 3 and 4 (for example, stainless steel, Hastelloy, Inconel) which are relatively thick and are cylindrical are hermetically connected at welded portions 3 m.

On the outer peripheral side of the bellows 2, a cylindrical braided body 6 having a cylindrical shape is fitted substantially coaxially. Tubular braid 6
Is made up of braids. The braid is formed as follows. That is, as can be understood from FIG. 2, an appropriate number of resin wire rods 60, which are flexible non-metal wire rods, are arranged in an aligned state, and a band member 61 is used. The braid is formed by spirally winding from one direction and the opposite direction.

The wire 60 which constitutes the braid which is the tubular braid 6 is made of non-metal, that is, aramid fiber. As the aramid fiber type, a meta type aramid type and a para type aramid type can be adopted. As can be understood from FIG. 1A, the end portions 63 of the tubular braided body 6 in the axial direction are attached to the outer peripheral surface of the base 3 and the outer peripheral surface of the base 4, respectively. In this state, a large number of ring-shaped fastening members 7 are wound around the portions of the tubular braid 6 that are attached to the mouthpieces 3 and 4. Thus, the end portions 63 of the tubular braided body 6 are fixed to the outer peripheral surface of the base 3 and the outer peripheral surface of the base 4, respectively. The base 3 is integrally fixed to the base body 30, and the base 4 is integrally fixed to the base body 40.

As the fastening member 7, a ring-shaped member is used as can be understood from FIG. 2, but the present invention is not limited to this, and a wire rod, a strip tape, a string-shaped member or the like can be used. According to this embodiment, the material of the fastening member 7 is similar to that of the caps 3 and 4, and specifically, metal (generally stainless steel) can be adopted. According to this embodiment, as a result of the end portion 63 of the tubular braid 6 being fastened by the fastening member 7, tension is applied to the tubular braid 6 in the axial direction thereof, that is, the arrow X1 direction.

In this way, the tubular braid 6 is applied with tension in the direction of arrow X1. By addition, Fig. 1 (B)
As can be understood from the above, the inner diameter of the inner wall surface of the tubular braided body 6 is somewhat reduced inward, that is, in the direction of the arrow Y1. As a result, the inner wall surface of the tubular braided body 6 strongly adheres to the top portion 20a of the mountain portion 20 of the bellows 2 in an inscribed state. The diameter of each wire 60 that constitutes the blade is Da in FIGS. 2 and 3.
Indicated by The side surface of one wire 60 is shown in FIG.
The cross section is shown in FIG. As can be understood from FIG. 3, one wire 60 is formed by twisting a large number of ultrafine fibers 60f. Therefore, as can be understood from FIG. 4 (B), when the force Fa is applied, the fibers 60f can be displaced relative to each other, so that one wire 60 can be flattened. It is considered that this flattening is more advantageous for improving the adhesion of the inner wall surface of the tubular braid 6 to the top 20a of the crest 20 of the bellows 2.

According to this embodiment, as can be understood from FIG. 1 (B), in the tubular braided body 6, the peak portion 2 of the bellows 2 is formed.
The braided ridge portion 6e that closely adheres to 0 and the braided ridge portion 6h that faces the valley portion 21 of the bellows 2 are alternately continuous in a wave shape. Further, as can be understood from FIG. 1B, a ring-shaped space 6k is formed between the valley portion 21 of the bellows 2 and the braid body valley portion 6h. The space 6k can ensure the allowance when the wall of the bellows 2 is deformed.

As described above, according to this embodiment, since the tubular braid 6 is firmly adhered to the top portion 20a of the mountain portion 20 of the bellows 2, the inner wall surface of the cylindrical braid body 6 and the mountain portion of the bellows 2 are adhered. In addition to increasing the adhesion with the top 20a of the bellows 20, the inner wall surface of the tubular braid 6 and the top 20a of the mountain portion 20 of the bellows 2
The contact area with is also increasing. According to this embodiment in which the above configuration is adopted, it is advantageous to suppress the excessive deformation of the bellows 2. In particular, according to this embodiment, the inner wall surfaces of the tubular braid 6 are in close contact with the tops 20a of all the peaks 20 of the bellows 2, which is advantageous for suppressing excessive vibration in the entire bellows 2.

Moreover, according to this embodiment, the tubular braid 6 is made of resin, not of hard metal. Therefore, since the flexible tube 1 is used in an environment where the vibration is severe or the relative displacement amount of the bases 30 and 40 is severe, even if the bellows 2 and the tubular braid 6 violently slide against each other, excessive friction sliding occurs. This is advantageous in preventing damage to the bellows 2 due to
Therefore, it is advantageous to improve the durability and life of the bellows 2.

According to this embodiment, unlike the prior art shown in FIG. 12, a space 6k is formed between the inner wall surface of the tubular braid 6 and the bellows 2 as shown in FIG. 1 (B). Therefore, the space 6k ensures the deformation tolerance of the wall of the bellows 2. Therefore, even when the bellows 2 is largely bent or a large displacement is added to the bellows 2, unlike the conventional technique shown in FIG. It is possible to prevent the bellows 2 from being damaged due to such stress concentration. Also in this sense, it is advantageous to improve the durability and life of the bellows 2.

According to this embodiment, the fastening member 7 includes the base 3,
Since it is made of the same material as that of No. 4, it is advantageous to bring the thermal expansion coefficient and the thermal contraction rate of the caps 3 and 4 close to or the same as the thermal expansion coefficient and the thermal contraction rate of the fastening member 7. Therefore, even when the flexible tube 1 is used in an environment where the temperature fluctuation is large,
For example, even when the flexible tube 1 is used in an environment where the temperature is lowered from the normal temperature range to a low temperature or an extremely low temperature, the fastening member 7
It is possible to suppress a dimensional change due to a temperature change between the base and the die 3, 4. Therefore, the fastening member 7 satisfactorily fastens the bases 3, 4 and thus the end portion 63 of the tubular braided body 6.

Therefore, the loosening of the fastening strength of the fastening member 7 due to the difference in the amount of thermal expansion or the amount of thermal contraction can be suppressed.
Therefore, it is advantageous to ensure the tension of the tubular braid 6 well for a long period of time and to inscribe the inner wall surface of the tubular braid 6 in the top 20a of the crest 20 of the bellows 6 for a long period of time. According to this embodiment, the central hole 3a of the mouthpiece 3, the central hole 2a of the bellows 2, and the central hole 4a of the mouthpiece 4 form a passage through which a fluid passes. The pressure of the fluid passing through the central hole 2a of the bellows 2 may be low pressure, medium pressure or high pressure. It is 0.8 to 7 at a low pressure and 10 at a high pressure.
It is about 20 ata. Note that ata means absolute pressure.

In this embodiment, the end portion 63 of the tubular braided body 6 is
Is fixed to the outer peripheral surfaces of the mouthpieces 3 and 4 with a ring-shaped fastening member 7. However, the present invention is not limited to this. The end portion 63 of the fastening member 7 is fixed to the bases 3 and 4 by impregnating and solidifying the adhesive.
A method of fixing to the outer peripheral surface may be adopted. By doing so, the liquid adhesive is impregnated and solidified between the wire rods 60 forming the end portions 63 of the tubular braided body 6, which is advantageous in preventing the fiber rods of the wire rods 60 from unraveling.

(Second Embodiment) FIG. 5 shows a second embodiment. This example also has basically the same configuration as that of the first embodiment, and basically has the same operational effect. That is, tension is applied to the tubular braid 6 in the direction of the arrow X1, and the inner wall surface of the tubular braid 6 strongly adheres to the top 20a of the ridge 20 of the bellows 2 in an inscribed state. ing.

Also in this example, the end portion 2r in the axial direction of the bellows 2 and the metal base 3 are hermetically connected to each other at the welded portion 3m. In FIG. 5, only one mouthpiece 3 is shown, but the same applies to the other mouthpiece 4. Since the welded portion 3m often has irregularities, if the flexible tubular braid 6 directly contacts the welded portion 3m, the tubular braid 6 may be damaged in a short period of time. Therefore, according to this example, a metal cylindrical collar 8 as a covering cylinder is coaxially fitted on the outer side of the welded portion 3m, and the tubular braid 6 is applied to the outer peripheral surface of the collar 8. ing. Therefore, it is possible to prevent the flexible tubular braid 6 from directly rubbing against the welded portion 3m, and effectively prevent the tubular braid 6 made of the resin wire material from being damaged.

It is more preferable that a lubricating film made of a material having a good lubricating property such as Teflon is laminated on the outer peripheral surface of the collar 8.
The collar 8 may be fixed to the base 3 or simply fitted. Further, as can be understood from FIG. 5, a ring-shaped groove portion 33 is provided on the outer peripheral surface of the base 3. The end 63 of the tubular braid 6 is adhered to the groove 33, and the fastening member 7 is further fastened to the adhered portion to fix the end 63 of the tubular braid 6 to the die 3.

According to this embodiment, the end portion 63 of the tubular braid 6 is applied to the groove portion 33 of the die 3 and the groove portion 3 is formed.
Since the fastening member 7 is fastened to 3, the end portion 63 of the tubular braid 6 and the fastening member 7 are advantageously prevented from being displaced in the axial direction. Therefore, the end portion 63 of the tubular braid 6 is
And the die 3 have good adhesion. (Third Embodiment) FIG. 6 shows a third embodiment. This example is also Example 1
Is basically the same configuration, and basically the same operation and effect are exhibited. That is, tension is applied to the tubular braid 6 in the direction of the arrow X1, and the inner wall surface of the tubular braid 6 strongly adheres to the top 20a of the ridge 20 of the bellows 2 in an inscribed state. ing.

In this example, the end portion 63 of the tubular braid 6 is attached to the ring-shaped groove portion 33 of the die 3, and a large number of ring-shaped first fastening members 7 are fastened at positions facing the groove portion 33. doing. Furthermore, the end portion 63 of the tubular braided body 6 in the axial direction is folded back to form a folded portion 63w. Then, the second fastening member 72 is fastened from above the folded-back portion 63w, whereby the end portion 63 of the tubular braided body 6 is fixed to the base 3.

The first fastening member 7 and the second fastening member 72 are made of the same material as the base 3 as described above, and the thermal expansion coefficient and the thermal contraction rate of the first fastening member 7 and the second fastening member 72 are the same. ,
The coefficient of thermal expansion and the coefficient of thermal contraction of the base 3 are made to correspond to each other to secure the fastening strength even if there is a large temperature change. According to this example, the first fastening member 7 faces the groove portion 33, and the folded-back portion 63w is fastened by the second fastening member 72, so that the end portion 63 of the tubular braided body 6 does not adhere well. Even better. Therefore, it is more advantageous to maintain the tension in the tubular braid 6 good for a long period of time.

(Fourth Embodiment) FIG. 7 shows a fourth embodiment. This example also has basically the same configuration as that of the first embodiment, and basically has the same operational effect. That is, tension is applied to the tubular braid 6 in the direction of the arrow X1, and the inner wall surface of the tubular braid 6 strongly adheres to the top 20a of the ridge 20 of the bellows 2 in an inscribed state. ing.

The different parts will be mainly described below. In this example, the outer peripheral surface of the mouthpiece 3 is formed with a conical tapered portion 35 whose outer diameter increases toward the opening 3t. Further, a male screw portion 36 is formed on the outer peripheral surface of the base 3. A relatively thick metal ring-shaped fastening member 7 is arranged on the outer peripheral side of the base 3. On the inner peripheral surface of the fastening member 7, a tapered surface-shaped tapered portion 75 having an inclination corresponding to the tapered portion 35 of the base 3 is formed.

As can be understood from FIG. 7, the end 63 of the tubular braid 6 is inserted between the tapered portion 35 of the die 3 and the tapered portion 75 of the fastening member 7. At this time, as can be understood from FIG. 7, the end 63 of the tubular braid 6 is inserted between the ring-shaped washer 83 and the shaft end surface of the fastening member 7, and the end 63 of the tubular braid 6 is folded back. The folded portion 63w is formed in advance.

As can be understood from FIG. 7, the female screw portion 85e of the nut member 85 is screwed into the male screw portion 36 of the base 3 and the washer 83 is axially oriented in the direction of arrow C1 (see FIG. 7). The end portion 63 of the tubular braided body 6 is sandwiched between the washer 83 and the fastening member 7 by pressing the
The taper portion 75 of the fastening member 7 and the taper portion 35 of the die 3 hold the end portion 63 of the tubular braided body 6. In this example, the washer 83, the fastening member 7, and the nut member 85 function as a fixing means for fixing the end 63 of the tubular braided body 6 to the outer peripheral surface of the base 3.

With the above structure, the end portion 6 of the tubular braid 6 is
3 is easy to put on and take off. Further, according to this embodiment, the base 3 and the fastening member 7 are of the same type of metal (generally stainless steel).
Therefore, the heat shrinkage rates of the base 3 and the fastening member 7 can be approximated or made equal to each other. Further, the heat shrinkage rate of the aramid fiber-based tubular braid 6 is determined by the metal die 3 and the fastening member 7.
It is smaller than the heat shrinkage rate of.

Therefore, the operating environment temperature is low (for example, 1
0 to 100K), the heat shrinks in the direction in which the gap between the outer peripheral surface of the base 3 and the inner peripheral surface of the fastening member 7 narrows, so that the space between the outer peripheral surface of the base 3 and the inner peripheral surface of the fastening member 7 decreases. The force for tightening the end portion 63 of the tubular braided body 6 inserted into the tubular braided body 6 increases, which is advantageous for further improving the adhesiveness of the tubular braided body 6. (Fifth Embodiment) FIG. 8 shows a fifth embodiment. This example is also Example 1
Is basically the same configuration, and basically the same operation and effect are exhibited. That is, tension is applied to the tubular braid 6 in the direction of the arrow X1, and the inner wall surface of the tubular braid 6 strongly adheres to the top 20a of the ridge 20 of the bellows 2 in an inscribed state. ing.

The different parts will be mainly described below. In this example, a ring-shaped groove 33 is provided behind the fastening member 7 on the outer peripheral surface of the mouthpiece 3, and a thin cylindrical portion 84 is coaxially extended on the inner peripheral portion of the metal washer 83. Then, the cylindrical portion 84 of the washer 83 is caulked into the groove 33 of the die 3 to fix the end 63 of the tubular braid 6 to the die 3. Also in this example, as can be understood from FIG. 8, the end portion 6 of the tubular braided body 6 is interposed between the washer 83 and the fastening member 7.
3 is inserted.

According to this example, since the base 3 and the fastening member 7 are made of the same material as described above, the outer peripheral surface of the base 3 is used when the environment temperature is low (for example, 20 to 100K). Since the heat shrinks in a direction in which the gap between the inner peripheral surface of the fastening member 7 and the inner peripheral surface of the fastening member 7, the end portion 63 of the tubular braided body 6 inserted between the outer peripheral surface of the die 3 and the inner peripheral surface of the fastening member 7. The power to tighten is increased.

Further, it is preferable that the washer 83 is made of the same material as the fastening member 7. With this, washers 8
The coefficient of thermal expansion or coefficient of thermal contraction of No. 3 and the coefficient of thermal expansion or coefficient of thermal contraction of the fastening member 7 can be approximated or made equal. Therefore, it is advantageous to maintain the caulking force of the cylindrical portion 84 of the washer 83, even if the washer 83 is used in an environment with large temperature fluctuations. (Sixth Embodiment) FIG. 9 shows a sixth embodiment. This example is also Example 1
Is basically the same configuration, and basically the same operation and effect are exhibited. That is, tension is applied to the tubular braid 6 in the direction of the arrow X1, and the inner wall surface of the tubular braid 6 strongly adheres to the top 20a of the ridge 20 of the bellows 2 in an inscribed state. ing.

The different parts will be mainly described below. In this example, a ring-shaped groove portion 77n is provided on the outer peripheral surface of the thick-walled fastening member 7, and a thin-walled cylindrical portion 86 is coaxially formed on the outer peripheral portion of the washer 83. The end portion 63 of the tubular braided body 6 inserted between the washer 83 and the fastening member 7 is then inserted.
The thin cylindrical portion 86 of the washer 83 is caulked in the groove portion 77n of the fastening member 7 so that the end portion 63 of the tubular braided body 6 is fixed to the die 3.

In this example, as can be understood from FIG. 9, since the folded-back portion 63w of the end portion 63 of the tubular braid 6 is surrounded by the thin-walled cylindrical portion 86 of the washer 83, the folded-back portion 63w is different from other portions. Direct contact with the member can be effectively prevented, and the protection of the folded-back portion 63w can be secured. In this example, the washer 83 is preferably made of the same material as the fastening member 7. By doing so, the coefficient of thermal expansion and coefficient of thermal contraction of the washer 83 and the coefficient of thermal expansion and coefficient of thermal contraction of the fastening member 7 can be approximated or made the same. Therefore, even if it was used in an environment with large temperature fluctuations, the cylindrical portion 86 of the washer 83
It is advantageous to maintain the crimping force.

(Seventh Embodiment) FIG. 10 shows a seventh embodiment. This example is applied to a heat insulating double flexible pipe. In this example, the basic diameter of the bellows 2 according to the first embodiment is indicated by Db. The second bellows 27 is arranged coaxially outside the bellows 2, and the basic diameter of the second bellows 27 is indicated by Dc.

In this example, the second bellows 27 described above is used.
The second tubular braid 69 having a diameter larger than that of the tubular braid 6 is used. That is, the bellows 2 having a basic diameter of Db is surrounded by the tubular braided body 6, and a second bellows 27 having a large diameter and a basic diameter of Dc is coaxially provided on the outer peripheral side of the tubular braided body 6. It is located in. A large-diameter second tubular braid 69 is arranged on the outer peripheral side of the second bellows 27. The second tubular braid 69 has a large diameter,
Basically, the material and structure are similar to those of the tubular braided body 6.

That is, as described above, the braid constituting the second tubular braided body 69 is a strip made of a suitable number of resin wire rods, which are flexible non-metal wire rods. It is spirally wound from one direction and the opposite direction so as to pass through alternately. The end portion 63 of the large-diameter second tubular braided body 69 has a metal-made tubular base 3
8 and the outer surface of the base 48, respectively. In this state, the fastening members 78 fix the outer surfaces of the mouthpieces 38 and 48.

Therefore, similarly to the tubular braid 6, the second tubular braid 69 is also applied with a tension in the direction of the arrow X1, and the inner wall surface of the second tubular braid 69 is the second tubular braid 69. It strongly adheres to the top portion 20a of the mountain portion 20 of the bellows 27 in an inscribed state. In this example, the central hole 27a of the second bellows 27 is substantially in a vacuum state, and the central hole 2a of the bellows 2 is
A cryogenic refrigerant such as helium passes through a.

(Embodiment 8) FIG. 11 shows an embodiment 8. This example also has basically the same configuration as that of the first embodiment, and uses the flexible tube 1 (1A to 1D) adopted in the first embodiment. In this example as well, basically the same action and effect can be obtained. Hereinafter, the different parts will be mainly described. This example is an example applied to a refrigerator for generating cryogenic temperature for obtaining refrigeration of liquid helium temperature, that is, cryogenic temperature (about 4 to 5K).

This refrigerator is a cold storage type refrigerator (for example,
Gifode McMahon refrigerator, Solvay refrigerator, etc., and a compression unit 10 having a built-in compressor for compressing a refrigerant.
0, and the low temperature generation part 200 which produces | generates a cryogenic temperature with a refrigerant. The compression unit 100 is composed of a first compression unit 101 and a second compression unit 102. The low temperature generation unit 200 generates an extremely low temperature (for example, about 70 to 15K, but is not limited to this). The first low temperature generation unit 201.
And a second low temperature generating unit 202 that generates an extremely low temperature lower than that of the first low temperature generating unit 201 (for example, about 4 to 5K, but is not limited to this).

As can be understood from FIG. 11, the first compression section 1
01 is a high pressure outlet 101h and a low pressure inlet 101 above it.
i. The second compression section 102 is also the high pressure outlet 102.
and a low pressure inlet 102i above the h. As can be understood from FIG. 11, the first low temperature generation unit 201 includes a high pressure inlet 201h and a low pressure outlet 201i above it. The second low temperature generator 202 has a high pressure inlet 202h,
A low pressure outlet 202i is provided above it.

As can be understood from FIG. 11, the high-pressure inlet 201h and the high-pressure outlet 101h are connected in an airtight state by using the flexible tube 1A according to the first embodiment. Similarly, using the flexible tube 1B, the low pressure outlet 201i and the low pressure inlet 101i
And are connected in an airtight state. Similarly, the flexible tube 1C is used to connect the high pressure inlet 202h and the high pressure outlet 102h in an airtight state. Similarly, the low-pressure inlet 102i and the low-pressure outlet 202i are connected in an airtight state using the flexible tube 1D.

In this example, the high-pressure (pressure: 10 to 20 ata) gaseous refrigerant (helium) compressed in the first compression section 101 is a high-pressure outlet 101h and the bellows 2 of the flexible tube 1A.
Passing through the high-pressure passage 2A and the high-pressure inlet 201h, reaching the cylinder chamber of the expansion cylinder 203 of the first low-temperature generating unit 201, being expanded by the operation of a piston (not shown) to generate a low temperature, and further the low-pressure outlet. 201i, low pressure passage 2B formed by bellows 2 of flexible tube 1B, low pressure inlet 101i
And returns to the first compression unit 101,
Is again compressed to a high pressure state and discharged again from the high pressure outlet 101h. This is repeated, and the expansion cylinder 203 generates a low temperature.

A high-pressure (pressure: 10 to 20 ata) gaseous refrigerant (helium) compressed by the second compression section 102.
Passes through the high-pressure outlet 102h, the high-pressure passage 2C formed by the bellows 2 of the flexible tube 1C, the high-pressure inlet 202h, the heat exchanger 301, and the heat exchanger 302 on the expansion cylinder 203 side. After passing through the heat exchanger 304 that has been cooled and further passed through the heat exchanger 303, the heat is passed through the heat exchanger 304 that is being cooled by the expansion cylinder 203, then passed through the heat exchanger 305, and passed through the Joule-Thomson valve 306. It reaches the exchanger 307, further passes through the heat exchangers 308 to 310 in order, passes through the low pressure outlet 202i, the low pressure passage 2D formed by the bellows 2 of the flexible tube 1D, and the low pressure inlet 102i, and then passes through the second compression portion 102. Then, the second compression unit 102 compresses it again to a high pressure state and discharges it again from the high pressure outlet 102h.
This is repeated. As a result, an extremely low temperature is generated in the heat exchanger 307 of the low temperature generation unit 200.

As can be understood from FIG. 11, the low temperature generator 2
00 is placed on the first underframe 210, and the first underframe 210 is elastically supported by the base 230 via the first elastic supporter 211 such as a spring. Similarly, the compression unit 100 also has the second underframe 22.
The second underframe 220 is also elastically supported by the base 230 via an elastic supporter 221 such as a spring. Therefore, when the base 230 vibrates or moves frequently, the first underframe 21
0 and the second underframe 220 are frequently displaced relative to each other. In this respect, according to this example, since the flexible tubes (1A to 1D) are used, it is possible to prevent the bellows 2 in the flexible tube 1 (1A to 1D) from being damaged due to the reason described above.

In this example, both the first underframe 210 and the second underframe 220 are mounted on the base 230 via the elastic supports 211, 221, respectively, but the first underframe 210,
Either one of the second underframes 220 may be directly fixed to the base 230. (Other Examples) In addition, the present invention is not limited to the embodiments described above and shown in the drawings. For example, the flexible tube is not limited to the refrigerator, but can be applied to other devices such as vehicles. ,
It can be appropriately selected as needed within a range not departing from the gist.

[0060]

According to the flexible tube of the first aspect, tension is applied to the tubular braid in the axial direction of the tubular braid.
The inner wall surface of the tubular braid strongly inscribes the top of the mountain portion of the bellows. Moreover, the contact area between the inner wall surface of the tubular braid and the top of the mountain portion of the bellows increases. As a result, it is advantageous to suppress excessive deformation of the bellows even if the flexible tube is used in an environment with severe vibration conditions or an environment with a large relative displacement. Further, it is possible to suppress excessive frictional sliding between the top of the mountain portion of the bellows and the inner wall surface of the tubular braid. Therefore, it is possible to prevent the bellows from being damaged by excessive frictional sliding. Therefore, it is very suitable when the bellows is thin.

Further, according to the flexible tube of the first aspect, the flexible tube shown in FIG.
Unlike the prior art shown in FIG. 2, the gel-like or elastomer-like cushioning material is not buried, so that a space is formed between the inner wall surface of the tubular braid and the bellows. Therefore, even when the bellows is greatly bent or a large displacement is applied to the bellows, it is possible to suppress the local concentration of stress on the bellows. Therefore, damage to the bellows due to excessive stress concentration can be suppressed.

According to the flexible tube of the second aspect, the end portion of the tubular braid is fixed to the outer peripheral surface of the die by the ring-shaped fastening member while being attached to the outer peripheral surface of the die. Therefore, it is advantageous to apply tension to the tubular braid in the axial direction thereof. Therefore, it is more advantageous to obtain the effect according to claim 1. According to the flexible tube of the third aspect, since the fastening member is made of the same material as that of the base, it is advantageous to bring the base and the fastening member close to or to have the same thermal expansion coefficient or thermal contraction rate. Is. Therefore, even when the flexible tube is used in an environment where the temperature changes drastically, it is possible to prevent the fastening strength of the fastening member that fastens the tubular braid due to the difference in the amount of thermal expansion or the amount of thermal contraction from being loosened. .

For example, even when it is used in a refrigerator in which the temperature is lowered from the normal temperature range to a low temperature or an extremely low temperature, the fastening member favorably fastens the tubular braid. Therefore, the inner wall surface of the tubular braid can be in good contact with the top of the mountain portion of the bellows for a long period of time. Therefore, it is possible to reduce or avoid damage to the bellows, which is advantageous for maintaining good refrigeration performance of the refrigerator.

According to the flexible tube of the fourth aspect, since the welded portion connecting the inner tube provided with the bellows and the mouthpiece is covered with the covering cylinder, it is possible to prevent the tubular braid from directly contacting the welded portion. . Therefore, it is advantageous for ensuring the protection of the tubular braid made of resin, and for improving the durability and life of the tubular braid. Therefore, it is advantageous for maintaining the vibration suppressing function of the bellows by the tubular braid for a long period of time.

According to the refrigerator of the fifth aspect, the low temperature generating portion and the compression portion, which are relatively displaced, are connected by the flexible tube according to the first aspect. Therefore, it is advantageous for suppressing the damage of the bellows that allows the refrigerant to pass therethrough for a long period of time, and thus can contribute to the securing of the refrigeration performance of the refrigerator.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a flexible tube according to a first embodiment.

FIG. 2 is a plan view showing a state where the end portion of the tubular braid is fastened by a fastening member.

FIG. 3 is a plan view showing one of the braid wire rods that form the tubular braid.

FIG. 4 is a configuration diagram showing a deformed state of one wire member of the braid constituting the tubular braid.

FIG. 5 is a sectional view of a main part of a flexible tube according to a second embodiment.

FIG. 6 is a sectional view of a main part of a flexible tube according to a third embodiment.

FIG. 7 is a sectional view of a main part of a flexible tube according to a fourth embodiment.

FIG. 8 is a sectional view of a main part of a flexible tube according to a fifth embodiment.

FIG. 9 is a sectional view of a main part of a flexible tube according to a sixth embodiment.

FIG. 10 is a sectional view of a flexible tube according to a seventh embodiment.

FIG. 11 is a configuration diagram of a refrigerator according to an eighth embodiment equipped with a flexible tube.

FIG. 12 is a cross-sectional view of a flexible tube according to the related art.

[Explanation of symbols]

In the figure, 1 (1A to 1D) is a flexible tube, 2 is a bellows (inner tube), 20 is a mountain portion, 20a is a top portion, 21 is a valley portion, 3 and 4 are caps, 3m is a welded portion, and 35 is a taper. Part, 75 is a tapered part, 6 is a tubular braid, 60 is a wire rod, 63 is an end part, 7
Is a fastening member, 8 is a collar (covered cylinder), 83 is a washer,
Reference numerals 85 respectively denote nut members.

Claims (5)

[Claims] 1. An inner pipe having at least a part of a bellows having a corrugated shape in which peaks and valleys are alternately continuous in a cross section along the axial direction, and a plurality of inner pipes arranged outside the inner pipe. And a tubular braid that is displaced in the inner diameter direction when tension is applied. The tubular braid is applied with tension in the axial direction thereof. The flexible tube is characterized in that the inner wall surface of the tubular braid is inscribed at the top of the mountain portion of the bellows with the addition. 2. A tubular braid, comprising: a tubular base to which at least one end of the inner tube in the axial direction is connected; and a ring-shaped fastening member mounted on the outer peripheral surface of the base. The flexible tube according to claim 1, wherein the end portion is fixed to the outer peripheral surface of the mouthpiece by the fastening member while being attached to the outer peripheral surface of the mouthpiece. 3. The flexible tube according to claim 2, wherein the fastening member is made of the same material as the base. 4. An end portion of the tubular braided body, comprising: a tubular mouthpiece to which at least one end of the inner tube in the axial direction is connected by a welded portion; and a covering cylinder that covers the welded portion from the outside. Part is attached to the outer peripheral surface of the coated cylinder,
The flexible tube according to claim 1, wherein the flexible tube is not in contact with the welded portion. 5. A refrigerator having a compression part for compressing a refrigerant and a low temperature generation part for expanding the refrigerant to generate a low temperature, and the relative displacement of the low temperature generation part and the compression part. A refrigerator having a flexible tube according to claim 1 connected to the part.