JPS5944211B2 - 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. The purpose of the method is to manufacture a synthetic resin flexible tube, which is characterized by inserting it into a blow molding mold 4 subjected to..., softening it, and blowing air into it for blow molding. However, when used as a flexible tube, when set to a certain bending angle state by bending, it is difficult to restore due to the elasticity of the synthetic resin and the bending angle can be maintained once set. It is on offer.

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 professional molding mold 4 includes a plurality of pieces, for example two mold pieces 4a, which grip the tube material 1 from the outer periphery with one end of the tube material 1 closed and the other end open.
4b, these mold pieces 4a, 4b
As shown in FIG. 2, a plurality of semi-annular recesses 3a, 3b for forming a plurality of grooves 3, 3, . However, inside the tubing 1 (
The tube material 1 is blow-molded as shown in FIG. 3 by blowing high-pressure air into the tube. In this way, a flexible tube in which the metal material 2 is applied to the outer periphery of the bellows part 5 as shown in FIG. 4 is obtained. Oka, as a metal material 2, it is relatively soft and has a small elastic repulsion force, and is easily plastically deformed even under high blow molding pressure.
In addition, a thin strip material having a relatively large shape-retaining force, such as soft iron, copper, aluminum, lead, tin, or other metals or alloys having these properties, is used. In addition, when the flexible tube is used as a joint, an elbow, etc., one end can be made into a small diameter part for internal insertion, and the other end can be made into a large diameter part 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. Since the pro-forming is performed by inserting it into a pro-forming mold with concave strips, the resulting flexible tube with bellows has a metal material that can be plastically deformed and has elasticity. This is a part with little repulsive force, and when bent at a predetermined angle, the elasticity of the synthetic resin suppresses the restoring properties of this part, allowing it to retain its shape in the predetermined bending shape, resulting in good workability. There is an advantage that a flexible tube can be obtained.

Moreover, this blow molding allows bending of the metal material to be performed at the same time, which has the advantage of facilitating molding.

[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. A schematic cross-sectional view of the state, and FIG. 4 is a perspective view of an embodiment of the flexible tube obtained by the same method. In the figure, 1 is a tube material, 2 is a metal material, 3 is a grooved strip, and 4 is a blow molding die.

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 multiple grooves on the inner periphery, softened, and then inserted into the mold. A method for manufacturing synthetic resin flexible tubes, which is characterized by blow molding by blowing air into them.