JPS5944210B2 - Manufacturing method of synthetic resin flexible tube - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention comprises a tube material 1 made of thermoplastic synthetic resin having a metal material 2 applied along the longitudinal direction on the outer periphery, a plurality of grooved stripes 3 on the inner periphery,
3... is inserted into the blow molding mold 4 which has been subjected to the above-mentioned blow molding mold 4. A synthetic resin flexible tube characterized by blow molding by softening the tube material 1 and blowing air into it while pressing the part of the material 1 on which the metal material 2 is applied to grooves 3, 3... The purpose of this method is to create a flexible tube that, when used as a flexible tube, can be bent to any desired bending angle without restoring due to the elasticity of the synthetic resin, thus maintaining the bending angle once set. An object of the present invention is to provide a method for manufacturing a synthetic resin flexible tube that can be used to produce flexible synthetic resin tubes.

Conventionally, flexible tubes have been made of thermoplastic synthetic resin tubes with bellows-like parts that can be bent to adjust the bending angle. There was a strong tendency to try to restore it, and it had the disadvantage of poor workability.

The present invention aims to eliminate such conventional drawbacks, and will be described in detail below with reference to the accompanying drawings.

In the present invention, as shown in FIG. 1, one or more metal members 2 are provided on the outer periphery of a tube material 1 made of any (preferably soft) thermoplastic synthetic resin such as polyvinyl chloride or polyethylene along its longitudinal direction. The applied material is Parylin, a rib blow molding material, and in this case, the metal material 2 is attached to the pipe material 1.
It can be carried out by any method, such as simultaneously extruding along the extrusion direction during extrusion molding, pasting and extruding, or pasting onto a pre-formed pipe material 1. However, the pipe material 1 with the metal material 2 attached to the outer periphery in this way
is preheated as parylene to soften it and then inserted into the blow molding mold 4. The blow molding mold 4 includes a plurality of pieces, for example, two mold pieces 4a and 4, which grip the tube material 1 from the outer periphery with one end of the tube material 1 closed and the other end open.
As shown in FIG. 2, a plurality of grooves 3 for forming the bellows part are formed on the inner periphery of these mold pieces 4a and 4b.
, 3, . . . are each provided with a plurality of semi-annular recesses 3a, 3b. Further, in this case, inside the tube material 1, as shown in FIG. The tool 5 is inserted and (high pressure) air is blown into the tube material 1 to perform blow molding of the tube material 1. At the same time, the presser jig 5 is operated to press the metal material 2 of the tube material 1 as shown in FIG. The part where the
, 3... In this way the fifth
As shown in the figure, a flexible tube in which the metal material 2 is applied to the outer periphery of the bellows part T is obtained. As for the metal material 2, metals such as soft iron, copper, aluminum, lead, tin, or others that have a small elastic force, can be plastically deformed, and have a relatively large shape-retaining force, or other materials having these properties. Metals and alloys are used.
Further, in the case of a joint, an elbow, etc., the flexible tube can have one end as a small diameter portion for insertion and the other end as a large diameter portion for external insertion. In the present invention, when molding a synthetic resin flexible tube having a bellows part, a plurality of thermoplastic synthetic resin tube materials having a metal material applied along the longitudinal direction on the outer periphery are used on the inner periphery. Because it is inserted into a blow molding mold with concave strips and blow molded, the resulting flexible tube with a bellows part can be plastically deformed in the metal part and has an elastic repulsion force. This is a part where there is little friction, and when it is bent to a certain angle, the elasticity of the synthetic resin suppresses the restorability of this part. This has the advantage of being able to maintain a predetermined bent shape and providing a flexible pipe with good workability.

In addition, during this professional molding, the metal-covered part of the pipe material is pressed against the grooves using a holding jig whose shape almost matches the grooves of the blow molding die. The bending process can be performed smoothly, even metal materials that are relatively hard and have great shape retention after bending can be used without difficulty, making it possible to obtain a flexible pipe with even better workability.

[Brief explanation of the drawing]

Fig. 1 is a partially omitted perspective view of an embodiment of the pipe material with metal material used in the present invention, Fig. 2 is a cross-sectional view of the same pipe material inserted into the mold, and Fig. 3 is the molding of the same material. FIG. 4 is a schematic cross-sectional view of the above molded state, and FIG. 5 is a perspective view of an example of the flexible tube obtained by the same method.

Claims (1)

[Claims] 1. A thermoplastic synthetic resin pipe material with a metal material applied along the longitudinal direction on the outer periphery is inserted into a blow molding mold with a plurality of grooves on the inner periphery, and the above-mentioned blow molding mold is inserted. Blow molding is performed by pressing the metallic part of the pipe material against the groove using a holding jig whose shape almost matches the groove of the mold, softening the pipe material, and blowing air into it. A method for manufacturing a synthetic resin flexible tube characterized by: