JPS6179619A - Manufacture of synthetic resin coiled tube - Google Patents

Abstract

PURPOSE:To very easily obtain coiled tube having circular cross-section and consequently excellent flow characteristics by a method wherein a straight tube, the cross-sectional form of which is formed elliptically in advance, is wound in such a manner that the surface in the direction of the major axis of an ellipse contacts with the surface of a cylindrical mandrel. CONSTITUTION:A straight tube 1 having elliptic cross-sectional form is wound around a mandrel in such a manner that the surface in the direction of the major axis of an ellipse contacts with the surface of the cylindrical mandrel by means of a proper means such as by rotating the mandrel or the like. Because the winding of the tube 1 around said mandrel produces the force of flatten the tube 1, the force contracts the major axis of an ellipse, resulting in turning the cross-sectional form into a circle. Accordingly, when the cross-sectional form of the tube 1 is made elliptically, said elliptic form must have the form, which turns into a circular form when the tube is wound in coils.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of manufacturing a tube for conveying pressure fluid.

[Prior Art] Conventionally, it has been known to coil a straight synthetic resin tube with a circular cross section in order to give elasticity to a tube for supplying pressure fluid and to prevent the tube from tangling. ing.

[Problems to be solved by the invention] Conventional synthetic resin coil tubes are made by winding a linear tube with a circular cross section around a core metal to form a coil, but the winding diameter, in other words, the radius of curvature When the diameter becomes small, the cross section of the tube becomes flattened by winding it around the mandrel, which causes a problem in that the effective cross-sectional area of the tube decreases and the flow characteristics deteriorate.

[Means for Solving the Problems, Effects 1] The manufacturing method of the invention provides a method for manufacturing a coil tube in which a linear synthetic resin tube is wound around the surface of a cylindrical core to form a coil. By using a method in which the cross section of the tube to be wound around the gold is elliptical, the major diameter direction of the tube is in contact with the surface of the metal core, the cross section is circular in the wound state, and the tube is fixed in that state. This solves the above problem.

To explain more specifically with reference to the drawings, in manufacturing the synthetic resin coil tube according to the present invention, first, 1.
A linear tube 1 made of synthetic resin and having an elliptical cross section as shown in FIG. Wind the tube around the mandrel. This mandrel may be a simple round bar, but it may also be one with a spiral groove provided at the position where the tube is wound.

By winding the tube 1 around the mandrel in this way, a force acts on the tube l to flatten it, so
Due to this force, the major axis of the ellipse is shortened, and the cross section becomes circular as shown in FIG. 2B.

Therefore, when the tube l is previously formed to have an elliptical cross-section, the ellipse must be such that the cross-section becomes circular when the tube is coiled.

The tube thus transformed into a circular cross-section is fixed in a coiled state and a circular cross-sectional state by means such as heat setting, which involves heating and cooling in a heat-deformable temperature atmosphere, and then the mandrel is removed. By this, the first
The coiled tube can have a desired shape as shown in the figure. In addition, the above heat setting can be carried out 2 times as necessary.
This may be repeated more than once, in which case the coil diameter can be reduced in stages.

Further, both end portions 3.3 of the coil tube in which the coiled portion 2 is formed in this manner are held in a circular cross-section by appropriate correction means such as pressurizing with a mold, and then fixed in this state by heat setting or the like. do.

[Effects of the Invention] As described in detail above, according to the method of the present invention, a linear tube formed in advance to have an elliptical cross section is wound with its long diameter surface in contact with the surface of a cylindrical mandrel. By rotating the tube, a coiled tube with a circular cross section can be obtained by simply using the force applied to the tube when winding the tube around the mandrel, and no other special operations are required. A circular coiled tube with good flow characteristics can be obtained.

[Brief explanation of drawings]

FIG. 1 is a side view of a coiled tube manufactured according to the present invention, FIG. 2A is a cross-sectional view of a tube used in the present invention, and FIG. 2B is a cross-sectional view of the tube after being coiled. 1.Tube, 2.e coiled part, 3.both ends.

Claims (1)

[Claims] 1. In manufacturing a coiled tube in which a straight synthetic resin tube is wound around the surface of a cylindrical mandrel, the cross section of the tube wound around the mandrel is elliptical, and its major diameter direction is A method for manufacturing a coil tube, characterized by winding the tube in contact with the surface of a core metal, making the cross-sectional shape circular in the wound state, and fixing the coil tube in that state.