JPH11344166A - Synthetic resin protection tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a synthetic resin protective tube which is excellent in flexibility and lineability and has good durability in which a tube wall is not damaged or broken even when used in a bent state. SOLUTION: When a synthetic resin pipe in which a reinforcing member made of a hard synthetic resin is spirally attached to an inner peripheral surface of a tube wall formed of a soft synthetic resin is bent at a minimum bending radius, the inside of the tube of the reinforcing member is bent. The inner diameter surface protruding in the radial direction of the tube body is configured to protrude more inward in the radial direction of the tube than the innermost surface of the contraction curved portion of the tube wall. The relationship between the length H in the radial direction of the pipe between the innermost surface of the pipe wall and the inner diameter surface of the reinforcing body and the pitch length L of the reinforcing body is expressed as H> L.
/ 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a synthetic resin pipe for protecting electric wires, cables, pipes and the like which are wired or piped to various machines.

[0002]

2. Description of the Related Art Conventionally, when the above-mentioned electric wires, pipes and the like are exposed and wired and laid, they are easily damaged, so that they are inserted into a protective tube for protection.

[0003] Incidentally, the above-mentioned protective tube is required to have excellent pressure resistance and bendability, and also to have good wire permeability so that an electric wire or the like can be easily inserted. In addition, the protective tube is used in a state where the protective tube is bent at a sharp angle. It is also desired that the wire is not damaged by contact abrasion with an electric wire or the like inserted therein.

[0004] As this kind of protective tube, for example, as shown in Japanese Utility Model Application Laid-Open No. 55-66278, a helical projection is formed along a corresponding position on the surface and the inner surface of a thin cylindrical tube. It is known that a thick portion is provided to reduce the frictional resistance at the time of pulling in the cable and to increase the crush resistance.

However, when such a protective tube is used in a bent state, the thin tube main body is bent toward the inside of the tube on the inner peripheral side of the bent portion and is positioned radially inward from the thick portion having a spiral projection shape. As a result, there is a problem that this portion is worn by contact with an electric wire or the like and is easily broken.

[0006]

SUMMARY OF THE INVENTION In view of the above-mentioned problems, the present invention is excellent in flexibility and lineability, and has good durability such that the tube wall is not damaged or broken even when used in a bent state. It is an object to provide a synthetic resin protective tube.

[0007]

SUMMARY OF THE INVENTION The present invention has the following arrangement to solve the above-mentioned problems. (1) A synthetic resin tube in which a reinforcing member made of a hard synthetic resin is spirally attached to an inner peripheral surface of a tube wall formed of a soft synthetic resin, and when the synthetic resin tube is bent at a minimum bending radius, A synthetic resin protective tube, wherein an inner diameter surface of the reinforcing member protruding into the inside of the tube protrudes inward in a radial direction of the tube body from an innermost surface of a contraction curved portion of the tube wall. (2) The relationship between the length H in the pipe radial direction between the innermost surface of the pipe wall and the inner diameter surface of the reinforcement and the pitch length L of the reinforcement is H
The synthetic resin protective tube according to the above (1), wherein> L / 2.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a partially sectional front view of a synthetic resin protective tube 1.
Reference numeral 2 denotes a tube wall which forms a tube main body formed of a soft synthetic resin. For example, a heat-fusible tape formed by extrusion molding of a soft synthetic resin is spirally wound to form side edges of adjacently polymerized tapes. Is a helical reinforcing member formed of a hard synthetic resin, for example, by helically winding a heat-fusible wire rod by extrusion molding of a hard synthetic resin on the inner surface of the tube wall 2. Is attached to the inner surface of the tube wall 2 and fused and integrated.

FIG. 2 is a partially enlarged cross-sectional view of the protective tube 1. The spiral reinforcing member 4 is attached to the tube wall 2 with its inner diameter surface 4a protruding into the tube, so that the protective tube 1 does not bend. In a substantially linear state, the contact area with the electric wire cord, the pipe, and the like is small, and the spiral reinforcing member 4 is made of a hard synthetic resin, so that it has good slipperiness and excellent lineability.

A pitch length between adjacent reinforcing members 4 is defined as L, and a pipe between the innermost surface 2a of the tube wall 2 between the adjacent reinforcing members 4 and 4 and the inner diameter surface 4a of the spiral reinforcing member 4 is defined as L. When the length in the radial direction is H, the dimensions are set so that H> L / 2.

FIG. 3 is a partial cross-sectional view showing the inside of the bent portion in a state where the protective tube 1 is bent at the minimum bending radius. The tube wall 2 contracts and flexes inward between the spiral reinforcements 4 and 4. However, the radial length of the contraction bending portion 3 protruding inward is a maximum of L / 2.
On the other hand, the spiral reinforcements 4 and 4 are dimensioned so as to protrude from the innermost surface 2a of the tube wall to H having a length exceeding L / 2, so that they are always contracted and curved no matter how steeply curved. The inner diameter surface 4a of the helical reinforcement 4 projects more inward in the radial direction of the tube than the innermost surface 2a of the portion 3. As a result, the electric wire or the like inserted into the protection tube 1 never contacts the soft tube wall, and there is no possibility that the tube wall is damaged.

[0012]

As described above, according to the present invention, the spiral reinforcing body of the hard synthetic resin is attached to the inner peripheral surface of the tube wall of the soft synthetic resin to form the uneven surface. Low frictional resistance and easy wiring work. Since the pipe body is made of a soft resin, the pipe body is excellent in flexibility and flexibility, and at the same time, a reinforcing force against an external pressure can be exerted by a spiral reinforcing body made of a hard synthetic resin. Even when bent to the minimum bending radius, the electric wire and the like do not contact the tube wall, so that the tube wall is not worn or damaged, and the protective tube can be freely bent and used.

[Brief description of the drawings]

FIG. 1 is a front view showing a cross section of a part of a synthetic resin protection tube.

FIG. 2 is a partially enlarged sectional view of a synthetic resin protection tube.

FIG. 3 is a partially enlarged sectional view of a bent state of the synthetic resin protection tube.

[Explanation of symbols]

 Reference Signs List 1 synthetic resin protective tube 2 tube wall 2a innermost surface of tube wall 3 shrinkage curved portion 4 spiral reinforcing member 4a spiral reinforcing member inner diameter surface

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Seiji Hattori 6 Titan Polymer, Shizuoka Pref. Inside the factory (72) Inventor Masataka Morikawa 6, Tanyo, Kakegawa-shi, Shizuoka Prefecture Inside the Tiger Polymer Co., Ltd. Shizuoka Factory

Claims (2)

[Claims] 1. A synthetic resin pipe in which a reinforcing member made of a hard synthetic resin is spirally attached to an inner peripheral surface of a pipe wall formed of a soft synthetic resin, wherein the synthetic resin pipe is bent at a minimum bending radius. A synthetic resin protective tube, characterized in that the inner diameter surface of the reinforcing member protruding into the tube protrudes inward in the radial direction of the tube from the innermost surface of the contraction curved portion of the tube wall. 2. The relationship between the length H in the pipe radial direction between the innermost surface of the pipe wall and the inner diameter surface of the reinforcement and the pitch length L of the reinforcement is H> L / 2. 2. The synthetic resin protective tube according to 1.