JP4486370B2 - Vibration absorption tube - Google Patents

Description

  The present invention relates to a vibration absorbing tube incorporated in a piping circuit that receives vibration.

Pipes made of metal such as copper are usually used for piping circuits where refrigerant circulates inside such as air conditioners, but the piping also vibrates and resonates due to the transmission of vibration from the drive source, Problems such as generation of noise and breakage of piping occur.
Therefore, a vibration absorption pipe is incorporated in a piping circuit that constantly receives vibration as described above, and the pipe itself absorbs vibration (for example, Patent Documents 1 and 2).

  As shown in FIG. 4, the conventional vibration absorbing tube is a flexible tube capable of absorbing vibration, which includes a metal bellows tube 100 and a tubular metal braided body 110 that covers the outside of the bellows tube. A metal pipe is brazed to the end portion of the bellows tube 100 as a base 120. At this time, a covering tube 130 is further attached to the end portion of the braided body 100 so as to cover the bellows tube 100 and the braid. The body 110 and the cladding tube 100 are brazed to the base 120 at the same time, with the end faces of the respective ends being substantially aligned. In FIG. 4, 140 is a brazing material. A part of the brazing material penetrates into the braided body.

  By this brazing, the bellows tube 100 and the base 120 are joined with sufficient strength, and the sealing performance of the joined portion is ensured. The braided body 110 and the cladding tube 130 are joined to the base 120 with sufficient strength. Therefore, this brazed part has a good connection structure that does not cause damage or leakage of the joint part or disconnection of the braided body even if it continues to receive vibration, and it becomes a vibration absorption pipe with high connection reliability as a whole. ing.

However, when the inventor paid attention to the manufacturing process of the brazing part, in order to achieve the above-described highly reliable connection state, the brazing operation requires high skill and the production efficiency is low. I understood it.
As shown in FIG. 4, it was found that the main cause requiring high skill in this brazing operation is that the three members simultaneously braze the bellows tube 100, the braided body 110, and the cladding tube 100 to the base.
That is, there are two main purposes for brazing this part, one is to hermetically join the bellows tube and the base, and the other is to fix the blade to the base. However, in the conventional brazing structure as shown in FIG. 4, since the three-layer body (lower bellows tube, middle blade, upper cladding tube) is brazed to the base at the same time, the lower bellows tube It becomes difficult to confirm the brazing state with the base. For this reason, it is difficult to stabilize the brazed state between the resulting bellows tube and the base. If the brazing between the bellows tube and the base is insufficient, leakage will occur from the gap between the bellows tube and the cladding tube, but this cannot be judged from the appearance of the brazing portion. As described above, it is difficult to confirm the state during the direct brazing operation and the quality confirmation of the result of the brazing of this part. It was overcome by skilled brazing skills.
JP 10-318479 A JP 2003-202088 A JP-A-3-138024 JP-A-4-172132 JP 7-151230 A JP 2000-271675 A

  The object of the present invention is to solve the above-mentioned problems and to absorb the vibration of the joint structure that can facilitate the joining process while maintaining the reliability of the joint state between the bellows pipe and the braided body in the base portion of the vibration absorbing pipe. To give to the tube.

The present invention has the following features.
(1) having a metal bellows tube and a tubular metal braided body covering the outside of the bellows tube;
At least one end of the metal bellows pipe is joined with a metal pipe as a base,
The metal braid extends to the arbitrary position in the longitudinal direction of the base so as to cover the outer periphery thereof, and an end portion of the metal braid is further provided with a covering tube covering the top,
The cladding tube is deformed so that the metal braided body is fixed to the base after being crimped in a state where the end surface on the distal side of the cladding tube is aligned with the end surface on the distal side of the metal braided body. And
In a state in which the cladding is subjected to caulking, further, the end face of each end side of the metal braid and the covering tube is brazed to the base in a state Tsu assortment each other, and a metal cladding tube A vibration-absorbing tube characterized in that wax penetrates from the end face on the end side into the braided body .
( 2 ) The cladding tube is provided with a through hole for exposing the metal braided body at a predetermined position from the end face on the terminal side, and the braze penetrates the metal braided body at least to a predetermined position through the through hole. The vibration absorbing tube according to (1) , wherein the vibration absorbing tube is configured to confirm that the
( 3 ) An annular recess or a single recess is provided on the inner side of the cladding tube and / or the outer side of the base so as to prevent the wax from flowing out and prevent it from coming off, as described in (1) or (2) above Vibration absorption tube.

In the vibration absorbing tube of the present invention, the structure in which the bellows tube, the braided body, and the cladding tube are brazed to the base at the same time as in the conventional vibration absorbing tube is eliminated, and as shown in FIG. The pipe 1 and the base 3 are joined independently at the S portion, the braided body 2 is extended to cover any position on the outer peripheral side surface of the base 3, and the cladding tube 4 is covered thereon, the cladding pipe 4 and the braided body 2 is brazed to the base 3 (reference numeral 5 in FIG. 1).
The present inventor considered that when the cladding tube 4 and the braided body 2 are joined to the base 3, the braided body is caulked and joined to the base only by caulking and plastically deforming the cladding tube. It was found that loosening occurs only with caulking joints due to the harsh usage environment subjected to vibration.
With the joining structure adopted in the present invention, the brazing state between the bellows pipe and the base can be directly confirmed, so the brazing quality is always stable without requiring high skill, and the step between the cladding pipe and the base Since it became smaller, brazing work became easier. Moreover, the brazed joint state between the cladding tube and the base has high mechanical strength and high reliability against vibration.

Hereinafter, a vibration absorbing tube of the present invention will be described with reference to a specific structure according to an embodiment.
As shown in FIG. 1, the vibration absorbing tube has a metal bellows tube (hereinafter referred to as bellows tube) 1 and a tubular metal braided body (hereinafter referred to as braided body) 2 that covers the outside of the bellows tube 1. Configured. A metal pipe is joined to at least one end of the bellows tube 1 as a base 3. The base may be joined to both ends of the bellows tube as in a conventional vibration absorbing tube, and both ends may have the same connection structure.
The braided body 2 extends to and covers a predetermined position on the base 3, that is, an intermediate part (or a terminal part) of the entire length of the base 3. The braided body 2 is further provided with a cladding tube 4 covering the end thereof, and the braided body 2 and the cladding tube 4 are brazed to the base 3 by a brazing material 5 with their end surfaces on the end sides substantially aligned. It is attached.

  By adopting this connection structure, as explained in the above [Effects of the invention], it is possible to easily braze without lowering the joining state of the brazing between the cladding tube and the base than in the past and without requiring excessive skill. Work becomes possible.

A conventionally known bellows tube and braided body may be used for the vibration absorbing tube.
For example, as the bellows pipe, those used in the vibration absorption pipes of Patent Documents 1 and 2, and those described in Patent Documents 3, 4, and 5 can be used.
Preferable materials for the bellows pipe when used for a refrigerant circulation pipe of an air conditioner include SUS304, SUS304L, SUS316, SUS316L, SUS321, and the like.

  The range of the inner diameter, the outer diameter, the thickness, etc. of the bellows pipe used for the vibration absorbing pipe is not limited, but the preferred range of the dimensions of each part of the bellows pipe is 7 mm to 50 mm as the inner diameter and 12 mm as the outer diameter. 70 mm, the wall thickness is 0.2 mm to 0.6 mm, and the pitch of the bellows in the longitudinal direction (the distance between the centers of two adjacent peaks) is 2 mm to 8 mm.

  The braid is also referred to as a “braid”. The braided structure is a basic one-layer structure in which a plurality of metal wires are arranged in parallel to form a bundle in a tubular shape with an intersection angle and number of strikes that do not cause a gap according to the outer diameter of the bellows tube. It is what. Depending on the use, the braided body may be superposed on a plurality of layers to improve the tensile strength. For the braiding pattern, the braiding technique, and the technique for covering the bellows tube, the prior art may be referred to.

As the metal strands used for the braided body, those manufactured for a conventionally known metal braided body may be used, and examples thereof include those specified in JIS G4309. The diameter of the metal strand is not limited, but is preferably 0.3 mm to 0.6 mm, particularly preferably 0.3 mm to 0.5 mm.
The material of the metal wire is not limited, but a material having strength and corrosion resistance is preferable, and an example of such a material is stainless steel. The stainless steel is preferably a stainless steel defined in JIS G4305 (for example, SUS304, SUS329J1, etc.). For example, an austenite-ferritic duplex stainless steel or the like, which is a further improvement of a JIS-defined stainless steel. It may be.

The base is a metal tube that is joined to the end of the bellows tube, and can be used for connection with other pipes and can function as a tube. The base may be further provided with a structure for connection with an external pipe line such as a screw or pipe joint structure at the outermost end. Further, the base is not limited to a simple straight pipe, but may be a bent pipe or a pipe whose diameter changes along the longitudinal direction.
The inner diameter or the outer diameter of both ends of the base may be determined by the shape and size of a mating pipe connected to each end (a bellows pipe at one end of the base and an external pipe at the other end).
The outer diameter of the end portion on the bellows tube side of both ends of the base is preferably 2 mm to 6 mm smaller than the outer diameter of the bellows tube, which is a preferable dimension in terms of joining the two. For example, when the outer diameter of the bellows tube is 26 mm and the inner diameter is 19 mm, the outer diameter of the base is preferably about 22 mm to 23 mm.
The thickness of the die is determined so as to have a sufficient strength with respect to the working pressure (design pressure). For example, when the working pressure is 3.45 MPa to 4.7 MPa and the outer diameter is about 30 mm, the thickness is preferably 1.6 mm to 2.1 mm.

The length of the base varies depending on the outer diameter, and there is a case where a joint mechanism for connecting to another pipe is further provided at the endmost part, but the length as a part of the base alone is 40 mm to 150 mm. Degree.
The length that the braided body covers the base (any position where the end of the braided body reaches, that is, the length from the joint surface of the base and the bellows tube to the end of the braided body) varies depending on the inner diameter and outer diameter of the base. 20 mm to 40 mm is appropriate.

  The base material is preferably a metal material that can withstand internal pressure and has corrosion resistance, and examples thereof include C1220T defined in JIS H 3300.

  The method for joining the base and the bellows tube is not limited, but brazing or the like may be mentioned as a preferable method from the viewpoint of ensuring mechanical strength and sealing performance.

The cladding tube is a metal tube for further improving the bonding strength between the braided body and the base, but it may function as a tube for preventing fraying of the strands at the end of the braided body and making the appearance beautiful. .
The material of the cladding tube may be a metal material that can be brazed, but is preferably a material that has corrosion resistance and can be crimped as described below. Examples of such a material include a copper pipe typified by C1220T and a stainless steel pipe typified by SUS304TP.

The inner diameter of the cladding tube may be determined according to the outer diameter when the braid covers the base. If the outer diameter of the die is 6 mm to 50 mm and the thickness of the braid is about 0.6 mm to 1.5 mm, the inner diameter of the cladding tube is preferably about 8 mm to 55 mm.
The thickness of the cladding tube is not particularly limited, but is preferably about 1 mm to 4 mm, particularly preferably 1 mm to 3 mm in consideration of strength, deformation, and an appropriate outer diameter as a product.
The length of the cladding tube is not particularly limited, but is preferably about 10 mm to 50 mm, and particularly preferably 10 mm to 30 mm.

In the step of brazing the braided body to the base, as shown in FIG. 1, the end faces of both ends are substantially aligned and the braided material 5 is soaked into the braided body 2 with the cladding tube being put on the braided body. Then, the cladding tube 4 and the braided body 2 are brazed to the base 3.
Preferred examples of the brazing material include silver brazing (JIS Z 3261), copper and copper alloy brazing (JIS Z 3262), and phosphorous copper brazing (JIS Z 3264).

As described above, the cladding tube and the braided body are brazed to the base, but in addition to this, by applying caulking to the cladding tube and plastically deforming it, the bonding strength becomes higher and a preferable bonding structure is obtained. .
The timing of the caulking process is preferably before the brazing process from the viewpoint of reducing the gap through which the brazing material flows. Further, by performing the caulking process first, the cladding tube and the braided body are temporarily fixed with the end surfaces aligned, and there is an advantage that the efficiency of the brazing operation is improved.

  The caulking process may be any process that allows the cladding tube to be locally, entirely or entirely pressed from the outside to be plastically deformed and pressure-bonded to the die together with the braided body. For a technique of caulking processing itself, for example, a conventionally known caulking technique such as Patent Document 4 may be referred to.

In the present invention, the cladding tube is covered on the braided body and brazed to the base. However, since the cladding tube covers the brazing material, the brazing material passes through the braided body from the end surface of the cladding tube toward the other end. It was newly found that it was difficult to know how far it had penetrated.
Therefore, in the present invention, as shown in FIG. 2, it is proposed that a through-hole 6 for exposing the braided body is provided in the cladding tube 4 at a predetermined position m from the end face on the terminal side. The “predetermined position” is a minimum brazing material penetration distance necessary for joining. By providing the through-hole 6, it is possible to visually confirm that the wax has penetrated the braided body to at least a predetermined position, and the braided body 2 is joined to the base 3 with sufficient strength. It can be confirmed easily.
In FIG. 2, as shown by hatching, the brazing material has penetrated to a position directly below the through hole 6, and the brazing material that has penetrated into the braided body can be visually confirmed through the through hole 6.

The position, shape, size, and number of through-holes provided in the cladding tube are not limited, but in order to ensure a sufficient brazing penetration distance (= strength) and confirm it clearly It is preferable that the position is 3 mm or more, particularly 4 mm or more from the side end face. The upper limit of the position from the end face is not particularly limited, but a practical range for avoiding excessive penetration is preferably 10 mm or less, particularly 8 mm or less.
The opening diameter of the through hole is not particularly limited, but is preferably about 1 mm to 2 mm in consideration of ease of confirmation and a decrease in strength of the cladding tube. A plurality of the through holes may be provided in consideration of strength in the circumferential direction of the body of the cladding tube.

When covering the braided body on the braid and brazing the base, as shown in FIG. 3, a recess 7 is provided on the inner side of the cladding pipe and / or the outer side of the base so that the brazing material can flow into the base and prevent it from coming off. preferable.
The concave portion may be an annular groove or a spiral groove around the inner circumferential direction of the cladding tube or the outer circumferential direction of the base, or may be a single hole or a rough surface with large irregularities. .
The recess may be provided either on the inside of the cladding tube or on the outside of the base, but if a recess is provided on the inside of the cladding tube, it becomes difficult to cover the braided body, It is preferable to provide only on the outer side of the base (however, in FIG. 3, concave portions are provided on both sides for the sake of explanation).
The number of recesses, the opening size, shape, and depth of the recesses may be appropriately determined according to the strength obtained by filling the recesses with wax.

  The use of the vibration absorption pipe is the same as that of a conventionally known vibration absorption pipe, and includes an air conditioner in which a compressor generates vibration, a dehumidifier, a refrigerant pipe in a refrigerator, and the like.

  According to the present invention, it is possible to provide a low-cost and high-performance vibration absorbing tube while maintaining the reliability in terms of strength of the vibration absorbing tube while facilitating the joining process of the base portion.

It is a figure which shows one Example of the vibrational absorption tube by this invention. In the figure, in order to show the sectional structure and the appearance at the same time, a center line is added, the section is shown above the center line, and the appearance is shown below. Similarly in the other figures, the hatching is added for the purpose of clearly distinguishing the region, not to show that it is a cross section. It is a fragmentary figure which shows the preferable aspect of the cladding tube in the vibrational absorption tube by this invention. In the figure, a cross section is shown entirely. It is a fragmentary figure which shows the preferable aspect of the brazing part in the vibrational absorption tube by this invention. In the figure, a cross section is shown entirely. It is a figure which shows the structure of the conventional vibration absorption pipe. As in FIG. 1, the cross section is shown above the center line, and the appearance is shown below.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Metal bellows pipe 2 Metal braided body 3 Base 4 Cladding pipe 5 Brazing material

Claims (3)

A metal bellows tube, and a tubular metal braided body covering the outside of the bellows tube,
At least one end of the metal bellows pipe is joined with a metal pipe as a base,
The metal braid extends to the arbitrary position in the longitudinal direction of the base so as to cover the outer periphery thereof, and an end portion of the metal braid is further provided with a covering tube covering the top,
The cladding tube is deformed so that the metal braided body is fixed to the base after being crimped in a state where the end surface on the distal side of the cladding tube is aligned with the end surface on the distal side of the metal braided body. And
In a state in which the cladding is subjected to caulking, further, the end face of each end side of the metal braid and the covering tube is brazed to the base in a state Tsu assortment each other, and a metal cladding tube A vibration-absorbing tube characterized in that wax penetrates from the end face on the end side into the braided body . The cladding tube is provided with a through hole that exposes the metal braid at a predetermined position from the end face on the end side, and the braze penetrates through the metal braid at least to a predetermined position through the through hole. The vibration absorbing tube according to claim 1 , wherein the vibration absorbing tube has a configuration capable of confirming The vibration absorbing tube according to claim 1 or 2 , wherein an annular recess or a single recess is provided on the inner side of the cladding tube and / or the outer side of the base so as to prevent wax from flowing in and preventing it from coming off.

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