JPH10336829A - Head guide for threading wire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to pass a guide wire even though a bent part has a small radius of curvature. SOLUTION: A head guide 12 has a shape line a thine pole and has an axial part 13 with flexural rigidity smaller than that of a guide wire 11. A rear end of the axial part 13 is joined rigidly to an end of the wire 11 through a connection part 14. In pushing work for inserting the wire 11 into a tube path 3, when a round swollen top part 13a of the head guide 12 goes against the tube wall, the axial part 13 is bent and the head guide 12 is passed. Since the flexural curvature of the axial part 13 is smaller than that of the wire 11, force for bending the axial part 13 is made small, and pushing force for passing the bent part is made small. As a result, the guide wire 11 can be passed even when the bent tube part has small radius (R) of curvature.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for passing a connecting rod through a conduit in which a cable is laid or a vacant conduit, for example, for drawing a sub duct for accommodating an optical fiber. In addition, the present invention relates to a tip guide for a wire rod attached to a tip of the wire rod.

[0002]

2. Description of the Related Art When laying a sub duct for storing an optical fiber in a conduit in which a cable is laid, usually, first, the through rod is passed through the conduit, and the through rod is passed through the conduit. A method called the bamboo threading method in which the subducts are connected and the subducts are pulled in is adopted. Generally, an FRP rod (a rod made of fiber-reinforced plastic), a carbon rod, or the like is used as the wire rod.

Conventionally, when this bamboo threading method is carried out, as shown in FIG. 4, a block-shaped tip head 2 is attached to the tip of a wire rod 1, and the pushing operation of the wire rod 1 (ie, the wire rod 1) is performed. Line work).

[0004]

As shown in FIG. 4, in the operation of connecting the connecting rod 1, the distal end head 2 is bent at a portion of the pipe 3 (curved pipe portion: the radius of curvature is indicated by R). ), The tip of the tip head 2 hits the inner wall of the pipe 3 at the start of bending, and then moves while being in contact with the inner wall of the pipe 3. As shown by, it passes while bending along the curve of the pipeline 3. Therefore, when the distal end head 2 passes through the curved pipe portion, in addition to the pushing force necessary to overcome the friction in the straight line portion of the communication rod 1, it corresponds to the bending force near the front end of the communication rod 1. The pushing force is required,
The pushing force is increased as a whole. The force required for rod bending is greater as the radius of curvature is smaller. Therefore, when the radius of curvature R of the curved tube is small, the force required for rod bending increases, and if it is attempted to force the tube to pass through the curved tube, the force required for bending is increased. There is a problem that the wire rod 1 buckles and the wire of the wire rod 1 becomes impossible.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional disadvantages, and an object of the present invention is to provide a guide rod for a wire rod which can easily wire the wire rod even in a curved pipe portion having a small radius of curvature. Aim.

[0006]

According to a first aspect of the present invention, there is provided a guide rod for a transmission rod, which has an elongated rod shape and has a lower bending rigidity than the transmission rod and a rear end of the shaft. A connecting portion for detachably and rigidly connecting to the distal end of the wire rod.

According to a second aspect, the connecting portion in the first aspect is
It is characterized in that the threaded portion formed at the tip of the through rod has a screw hole into which the thread is screwed.

A third aspect of the present invention is characterized in that a rounded enlarged portion is provided at the tip of the shaft portion in the first aspect.

[0009]

FIG. 1 is a block diagram showing an embodiment of the present invention.
A description will be given with reference to the embodiment shown in FIGS. In FIG. 1, reference numeral 11 denotes a wire rod formed of an FRP rod, a carbon rod, or the like, and a wire rod tip guide 12 according to one embodiment of the present invention is attached to the tip of the wire rod 11. As shown in FIGS. 1 and 2, the distal end guide 12 is formed in an elongated rod shape and has a bending rigidity smaller than that of the through rod 11, and a rear end of the through hole
And a connecting portion 14 for detachably and rigidly connecting to the distal end of the connector. The connecting portion 14 has a screw hole 14a into which the screw portion 11a formed at the tip of the wire rod 11 is screwed. In addition, a rounded enlarged portion 13a, that is, a rounded portion is provided at the tip of the shaft portion 13 in order to reduce sliding resistance and not to damage an existing cable in the pipeline. The tip itself of the shaft portion 13 may be rounded to form a rounded portion.

As a mode of making the bending rigidity of the shaft portion 13 smaller than the bending rigidity of the wire rod 11, the same material is used, but when the diameter of the shaft portion 13 is made smaller than the diameter of the wire rod 11, the diameter is the same. However, when the material of the shaft portion 13 is made of a material whose longitudinal elastic modulus is smaller than that of the wire rod 11, there are three cases in which both of the above and both are adopted. The embodiment is the case of, for example, the diameter of the shaft portion 13 is 9 mm when the diameter of the wire rod 11 is 11 mm.

A wire rod 1 with the above-mentioned tip guide 12
As shown in FIG. 3, when the end guide 12 passes through the curved pipe portion in the line 1 work, the tip of the end guide 12, that is, the enlarged portion 13 a at the end of the shaft portion 13, forms an inner wall at which the pipe line 3 starts to bend. , And moves while being in contact with the inner wall of the pipeline 3. Meanwhile, as indicated by the two-dot chain line,
It passes while bending along the bend of the pipeline 3, but the shaft 1
Since the bending stiffness of No. 3 is smaller than that of the wire rod 11, the bending force for bending the shaft portion 13 is small, and therefore, the pushing force required to apply this bending force is small, and the pushing force as a whole is small. Smaller. Therefore, even if the radius of curvature R of the curved pipe portion is small, the increase in the force required for rod bending is small, and the situation in which the wire rod 11 cannot be routed rarely occurs.

The structure of the connecting portion 14 for rigidly connecting the shaft portion 13 to the end of the wire rod 11 is not limited to the embodiment. For example, a structure in which a threaded portion formed at the rear end of the shaft portion 13 is screwed into a threaded hole drilled on the side of the wire rod 11 or a means that does not rely on screws is optional. In short, it is not a hinge connection or a connection that is easily bent at the connection part,
Any connection portion having a high rigidity that has a bending rigidity greater than the bending rigidity of the shaft portion 13 may be used.

[0013]

According to the end guide for a wire rod of the present invention, since it has an elongated structure having a shaft portion having a smaller bending rigidity than the wire rod, it easily bends when passing through a curved pipe portion. Therefore, it is possible to easily pass through the wire rod even in a curved pipe with a small radius of curvature.

[Brief description of the drawings]

FIG. 1 is a front view of the vicinity of a distal end of a wire rod equipped with a wire rod tip guide according to an embodiment of the present invention.

FIG. 2 is an enlarged view partially showing a vicinity of a connection portion of a distal end guide in FIG. 1 in a cross section.

FIG. 3 is a view for explaining a situation in which the distal end guide passes through a curved pipe portion in a wiring operation of the wiring rod to which the distal end guide is attached.

FIG. 4 is a view for explaining a situation in which a distal end head passes through a curved pipe portion in a conventional wiring operation of a wiring rod to which a distal end head is attached.

[Explanation of symbols]

 Reference Signs List 3 Pipeline 11 Communication rod 11a Screw part 12 Tip guide 13 Shaft part 14 Connection part 14a Screw hole

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Teiji Suzuki 1-5-1, Kiba, Koto-ku, Tokyo Inside Fujikura Co., Ltd. (72) Inventor Hidetoshi Katahira 1-5-1, Kiba 1-chome, Koto-ku, Tokyo Stock Company (72) Inventor Toshio Horikoshi 1-3-1 Uchisaiwaicho, Chiyoda-ku, Tokyo Tokyo Electric Power Company (72) Inventor Koichi Yokosuka 1-1-3 Uchisaiwaicho, Chiyoda-ku, Tokyo Tokyo Electric Power Company Inside

Claims (3)

[Claims] A shaft portion having an elongated rod shape and a bending rigidity smaller than that of the wire rod; and a connecting portion for detachably rigidly connecting a rear end of the shaft portion to a tip of the wire rod. Characteristic tip guide for wire rod. 2. The guide for a wire rod according to claim 1, wherein the connecting portion has a screw hole into which a screw portion formed at the tip of the wire rod is screwed. 3. The guide according to claim 1, wherein a rounded bulge is provided at a tip of the shaft.