JP4586516B2 - Joining structure of metal flexible tube and connecting joint - Google Patents

Description

  The present invention relates to a joining structure of a metal flexible tube and a joint for connection.

  In order to give flexibility and flexibility to the entire tube, it is assumed that the tube wall shape in the vertical cross-sectional shape of the metal tube exhibits a continuous wave shape in a metal tube made of stainless steel, which is originally a rigid material. A metal flexible tube is known.

  The metal flexible tube is generally configured such that the tube appearance is formed in a ridge-and-valley uneven shape that is continuous in a spiral or bellows shape.

  While such a metal flexible tube has good pressure resistance while having flexibility and flexibility due to the above-described ridge-and-valley uneven structure, it is easy to connect various devices, For example, in comparison with a non-metallic flexible tube typified by rubber, it has been effectively used as a material having extremely high non-permeability with respect to chemicals, gases, and the like.

  Usually, when the metal flexible tube is connected to a chemical apparatus or the like, a connection joint for assisting the connection with the apparatus to be connected is joined to the end opening of the metal flexible tube.

  In order to perform this joining, welding is generally used (Patent Document 1). However, welding provides high airtightness at the joint by integrating the members to be welded. Deterioration phenomenon occurs in metal flexible tube material. Due to this deterioration phenomenon, there is a problem that the metal flexible tube may be damaged at the deteriorated part before reaching the expected service life due to an external force such as bending or a change in internal pressure. It was.

  Various proposals have been made to solve such problems, but none of them are effective depending on the type of external force that can deform the deteriorated portion, or increase the number of parts and complicate assembly. There are new problems such as very high cost.

  For example, it has been considered to lengthen the pipe-shaped part at the tip of the metal flexible tube to protect the material deteriorated part due to welding, but this method has some effect on the bending force applied to the metal flexible tube. However, the effect was not recognized for the deformation of the metal flexible tube based on the change of the internal pressure caused by the pulsation of the fluid passing through the inside.

  In addition, in order to protect the material deteriorated part due to welding, a reinforcing member for fitting the corrugated shape of the metal flexible tube to prevent the displacement of the tube wall is attached to the tube wall near the end of the metal flexible tube. (Patent Document 2). However, in this method, it is necessary to manufacture a plurality of reinforcing members with high dimensional accuracy and then to join them together by welding or the like, resulting in an increase in the number of parts and a complicated manufacturing process. It was.

On the other hand, as a method of connecting the connecting joint and the metal flexible tube without using a welding technique, an outer layer blade is fitted on the outer surface of the end of the metal flexible tube, and the metal flexible tube and A sleeve is interposed between the outer layer blade, the insertion tube portion of the connecting joint is inserted into the extended end portion of the metal flexible tube, and the socket disposed on the outer peripheral surface of the outer layer blade is compressed. In the joint portion of the metal flexible tube that crimps and joins the blade, the sleeve, and the metal flexible tube to the insertion tube portion of the connection joint, a sealing material is interposed between the insertion tube portion of the connection joint and the metal flexible tube. A technique called “Patent Document 3” has been proposed. However, in this method, since that does not extend to high airtightness of definitive to welding as provided sealant, there is a problem that the fluid that can be used is limited.
JP 2004-52812 A Japanese Utility Model Publication No. 5-12881 Japanese Utility Model Publication No. 4-82484

  In view of the above-described points, the object of the present invention is excellent in airtightness at a joint when joining a metal flexible tube and a joint for connection, and an external force such as bending or change in pressure in the tube is applied. It is an object of the present invention to provide a joint structure that can be used while maintaining desired performance over a long period of time without being damaged.

The joining structure of the metal flexible tube and the joint for connection of the present invention that achieves the above-described object has the following configuration (1).
(1) A structure in which a metal flexible tube and a joint for connection are joined, the end of the joint for connection being inserted into an end of the metal flexible tube, and a joint on the outer surface side of the insertion portion A cover is attached, and the end of the metal flexible tube is tightly joined to the end of the connection joint by crimping the joint cover, and the end of the end of the metal flexible tube and the end The position at which the welded joint, which is the tip of the end of the metal flexible tube, projects from the surface of the end of the joint for connection to the outside through the region covered by the joint cover. bonding structure of the connection joint with the metal flexible tube, characterized in that formed by joining by welding in.

Moreover, in the joining structure of the metal flexible tube of this invention and the coupling for connection, Preferably, it has the specific structure of the following (2) .
(2) arranged reinforcing steel wire braid on the outer surface of the end portion of the metallic flexible tube, further covered state of the joint cover on the outside of該補steel wire braid for strength, the caulking of該継hand cover The joint structure of the metal flexible tube and the joint for connection according to the above (1), which is performed through a reinforcing steel wire blade.

  According to the present invention, when joining a metal flexible tube and a joint for connection, the joint is excellent in airtightness at the joint, and is not damaged even if an external force such as bending or a change in pressure in the tube is applied. A joint structure of a metal flexible tube and a joint for connection that can be used while maintaining desired performance for a long period of time is provided.

  Hereinafter, the joint structure of the metal flexible tube and the joint for connection according to the present invention will be described in more detail with reference to the drawings.

FIG. 1 schematically shows an example of a joint structure of a metal flexible tube and a joint for connection according to the present invention, and is a schematic cross-sectional model view of a main part of the joint structure.

The joint structure of the metal flexible tube and the joint for connection according to the present invention is a structure for joining the metal flexible tube 2 and the joint for connection 1 as shown in the schematic model structure in FIG. The end portion 1 ′ of the connecting joint 1 is inserted into the end portion 2 ′ of the tube 2, the joint cover 4 is mounted on the outer surface side of the insertion portion, and the joint cover 4 is caulked to tighten the metal The end portion 2 ′ of the flexible tube 2 made of the product is tightly joined to the end portion 1 ′ of the connection joint 1, and the end portion of the end portion 2 ′ of the metal flexible tube 2 and the end portion of the connection joint 1 The metal flexible tube 2 and the connecting joint 1 are joined by welding the surface of 1 '.

  That is, the joining structure of the present invention is based on a combination of two kinds of joining means, that is, a caulking means and a welding means. The caulking is performed by joining the two by a mechanical fastening force. It gives excellent airtightness.

In FIG. 1, an arrow A indicates a caulking force applying portion, 5 indicates a welded portion, and the welded portion 5 passes through a region covered with a joint cover 4 as shown in FIG. Welding is performed at a position that protrudes out of the region . Of course , welding joining may be performed at a plurality of locations in the joint axial direction. In any case, the weld joint is welded over the entire periphery of the end portion 2 'of the metal flexible tube 2 and the end portion 1' of the connecting joint 1 so that high weld-tightness is realized by the weld joint portion. It is important to let

  Since the joining structure according to the present invention is based on a combination of two kinds of joining means, that is, a caulking means and a welding means, as described above, a high airtightness can be obtained by the weld joint, and the weld joint can be obtained. Since the joining force is mechanically strongly applied by the caulking means, it is not subject to deformation due to external force, and deformation of the metal flexible tube is due to bending or internal pressure. Regardless, it contributes to maintaining a stable and strong joint structure and good airtightness.

In the joining structure of the metal flexible tube and the joint for connection according to the present invention, as shown in FIG. 1, a reinforcing steel wire blade 3 is provided on the outer surface of the end 2 ′ of the metal flexible tube 2 as shown in FIG. Further, the joint cover 4 is covered on the outer side of the reinforcing steel wire blade 3, and the joint cover 4 is caulked through the reinforcing steel wire blade 3. The reinforcing steel wire blade 3 is formed by braiding a wire rod into a cylindrical shape, and is preferably attached to the outer surface of the metal flexible tube 2 and integrated with the flexible tube 2. The reinforcing steel wire blade 3 is effective in improving the pressure resistance of the flexible tube.

  Further, the caulking force of the joint cover 4 is appropriately determined in accordance with the required pressure resistance performance, and when high pressure resistance is required, the ends of the reinforcing steel wire blade 3 and the metal flexible tube 2 are used. 2 'needs to be given a stronger bonding force. In this case, a protective sleeve made of a soft material is attached between the reinforcing steel wire blade 3 and the end 2 'of the metal flexible tube 2 so that the joining force is evenly distributed in the circumferential direction. desirable. In any case, the bonding structure according to the present invention remains stable and strong and maintains good airtightness.

FIG. 1 shows an example of a joining structure of a metal flexible tube and a joint for connection according to the present invention, and is a schematic cross-sectional model view of a main part of the joining structure.

Explanation of symbols

1: Connection joint 1 ': End of connection joint 2: Metal flexible tube 2': End of metal flexible tube 3: Reinforcing steel wire blade 4: Joint cover 5: Welded part A: Clamping force Granting part

Claims (2)

A structure in which a metal flexible tube and a joint for connection are joined, and the end of the connection joint is inserted into the end of the metal flexible tube, and a joint cover is covered on the outer surface side of the insertion portion. The end of the metal flexible tube is tightly joined to the end of the connection joint by crimping the joint cover, and the end of the end of the metal flexible tube and the connection joint The welded joint, which is the tip of the end of the metal flexible tube, is welded to the surface of the end of the metal at a position where the welded joint protrudes out of the region through the region covered by the joint cover. A joining structure of a metal flexible tube and a joint for connection, characterized by being joined together. Disposing a reinforcing steel wire braid on the outer surface of the end portion of the metallic flexible tube, further covered state of the joint cover on the outside of該補steel wire braid for strength, crimping the reinforcing steel該継hand cover The joint structure of a metal flexible tube and a joint for connection according to claim 1 , wherein the joint structure is performed via a wire blade.

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