JPH0767233A - Suspension clamp - Google Patents

Abstract

PURPOSE:To achieve a specified gripping force while lowering the nicking rate by setting the diameter of a circle being formed the wire grooves in a clamp body are collected shorter than the nominal wire groove diameter corresponding to the nominal cross-sectional area regulated by JIS. CONSTITUTION:The wire groove diameter D is set shorter by 1-5% than a conventional one. When the wires L are gripped by a conventional clamp, each strand L', L'... can move relatively freely and although a part of gap is filled it is filled unevenly thus providing a cross-section which is not right circle. When the strands L', L'... are gripped by a clamp 1, free movement thereof is blocked and the strands L', L' are joined to fill the gap uniformly. Consequently, they are clamped while sustaining the original profile and the nicking rate is lowered. The clamp 1 provides a gripping force higher than a specified level while requiring a shorter marginal length and the mechanical characteristics of wire is sustained well while lowering the nicking rate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a suspension clamp, and more particularly to a nicking rate indicating the degree of deformation of a filament when grasping the filament, that is, an initial wire diameter d (m) before grasping.
m), the percentage of the initial wire diameter d when the wire diameter after gripping is d ′ (mm) ((d−d ′) / 100 × 10
0) (%) can be reduced.

[0002]

2. Description of the Related Art Conventionally, a suspension clamp of this type (hereinafter referred to as a clamp) has a wire fitting (wire) inserted in a wire groove provided in a clamp body, and a pressing metal fitting having a similar wire groove from above. , And the line is gripped by the clamp body.

A conventional clamp is further illustrated by using FIG. 1 showing a part of the left half of the clamp in cross section and FIG. 2 showing the cross section along the line AA of FIG. 1 and showing a part of the left half in cross section. Will be described.

The illustrated clamp 1 is a free-center type clamp, and the clamp body 2 is rotatably supported by a pair of link fittings 3a and 3b on both sides of the central portion thereof, and the link fitting 3a is also provided. , 3b are configured to be indirectly attached to a transmission line tower (not shown) via clevis fittings 4.

On the upper surface of the clamp body 2 in the longitudinal direction, there is provided a line groove 5 having a semicircular cross section adapted to a line (not shown) supported by the clamp.

The pressing metal fitting 6 has a line groove 7 similar to the above-mentioned line groove on the lower surface, and is made to face each other so that the directions of both wire grooves 5 and 7 are the same, and four bolts and nuts 8, 8 ... It is attached to the clamp body 2.

The diameter D of the circle formed when the two wire grooves 5 and 7 face each other (hereinafter, this diameter is referred to as wire groove diameter) is
It is determined by the Japanese Industrial Standards (hereinafter referred to as JIS) according to the cross-sectional area of the filament supported by the clamp 1.

Table 1 shows a steel-core aluminum stranded wire (hereinafter referred to as ACSR) as a filament, which is wound on a pre-homed doormer rod (the filament of the clamp portion is covered with a plurality of aluminum alloy strands to prevent lightning damage). Etc.) to prevent the damage to the wire and prevent the fatigue due to the vibration of the wire)) and shows a part of each nominal wire groove diameter for each nominal cross-sectional area.

[Table 1]

[0010]

However, in the above-mentioned conventional clamp, although the wire groove diameter D is determined by JIS, there is a disadvantage that the nicking rate is large.

That is, in order to support the linear strip with the clamp 1, it is necessary to press the linear strip with the pressing metal fitting 6 to obtain a predetermined gripping force, and some nicking is inevitable, but nicking is necessary. If it becomes too large, that is, if the filament is greatly deformed, it is feared that the mechanical properties of the filament are adversely affected.

Therefore, an object of the present invention is to provide a clamp which can obtain a predetermined gripping force and has a small nicking rate.

[0013]

In order to achieve the above-mentioned object, a clamp according to the present invention inserts a wire into a wire groove provided in a clamp body, and inserts the wire into the wire groove. In the clamp that holds the wire on the clamp body by pressing it with the holding metal fitting, the diameter of the circle formed when the wire grooves are aligned with each other is the nominal cross-sectional area of the wire determined by the Japanese Industrial Standards. It is characterized by making it smaller than the nominal wire groove diameter corresponding to.

[0014]

In the above structure, when the wire is pressed in the wire groove of the clamp body and the wire groove of the retainer, it is gripped by the clamp so as to fill the gap between the wires forming the wire, Each strand maintains its original shape. Therefore, the clamp has a small nicking rate.

[0015]

EXAMPLE A clamp according to an example of the present invention will be described below. The clamp according to the present embodiment has the same configuration as that shown in FIGS. 1 and 2, and is different from the conventional one in that the wire groove diameter D is smaller than that specified by JIS.

That is, the wire groove diameter D according to this embodiment is about 1 to 5% smaller than that of the prior art. Specifically, 54 mm is formed to 52 mm in the ACSR having a nominal cross-sectional area of 610 mm ² .

FIG. 3 is an explanatory view showing an outline of a state in which the filament L of the ACSR is gripped by the conventional clamp and when it is gripped by the clamp according to this embodiment.

FIG. 3 (a) shows a state before gripping with a clamp, in which the filament L is a plurality of strands L ', L' ... Arranged around the steel core S with a predetermined gap. In other words, the strands L ', L' ... Are loosely twisted around the steel core S.

FIG. 3 (b) shows a state in which the wire is gripped by a conventional clamp, and since the wire groove diameter is sufficiently large, each of the wires L ', L' ... Relatively (see FIG. (Compared with (1)), some gaps are filled, but they are not uniform, and the cross-sectional shape of each wire (L ', L' ...) is not a perfect circle.

FIG. 3 (c) shows a state of being gripped by the clamp according to this embodiment, and since the wire groove diameter is smaller than that of FIG. 3 (b) described above, the individual wires L ', L' ... Are prevented from moving freely, are joined to each other so that the gaps between the individual wires L ', L' ... Are evenly filled, and are clamped while maintaining the original shape of each of the wires L ', L' ... .

FIG. 4 is a graph showing the nicking characteristics of ACSR610 mm ² , in which the solid line shows the nicking rate (%) of the conventional clamp of D = 54 mm, and the chain line shows the nicking of the clamp of D = 52 mm according to this embodiment. The rate (%) is shown.

From this figure, it is apparent that the clamp according to this embodiment has a smaller nicking rate. In this figure, the unit length compression force (tightening force / holding length) on the horizontal axis corresponds to the fastening force when the holding metal fitting 6 is set by the bolts / nuts 8, 8 ...

[0023]

[Experimental Example] A clamp with an ASR of 610 mm ² with a wire groove diameter D of 52 mm and a presser foot length of 120 mm is tightened with a force of 110 kg.
When gripped at f / mm (tightening torque of 1000 kgf · cm), the gripping force of the filament was 5300 kgf or more, and the nicking rate at that time was 7.7%. In addition, the tightening force described above is 100 kgf / mm (tightening torque 900 k
The gripping force (gf · cm) was 5300 kgf or more, and the nicking rate was 7.1%.

On the other hand, with the conventional clamp having a wire groove diameter D of 54 mm and a presser foot length of 120 mm, the same line is tightened with a clamping force of 1 mm.
10 kgf / mm (tightening torque 1000 kgf ・ c
The gripping force when gripped in m) was 5300 kgf or more, but the nicking rate was 14.3%.

The tightening force described above is 100 kgf / mm.
The gripping force when the tightening torque was 900 kgf · cm was 5300 kgf, and slippage occurred, which was unusable. The nicking rate at this time was 13.2%.

As is clear from the above experimental results, the clamp according to the present invention can obtain a gripping force more than a predetermined value and can have a small nicking rate even when the clamp length is shorter than that of the conventional clamp. . The experimental results disclose the unit length compressive force-nicking characteristics when the pre-homed armor rod winding is attached, but the same nicking characteristics can be obtained even when the pre-homed armor rod winding is removed. You can

[0027]

In the clamp according to the present invention, the diameter of the circle formed when the two wire grooves are aligned with each other is smaller than the nominal wire groove diameter corresponding to the nominal cross-sectional area determined by the Japanese Industrial Standard of the wire. Since it is made small, the nicking rate can be made small, and therefore, the mechanical properties of the filament can be kept good.

[Brief description of drawings]

FIG. 1 is a front view showing a schematic configuration of a clamp with a part thereof shown in cross section.

FIG. 2 is a cross section taken along the line AA of FIG.

FIG. 3 is an explanatory diagram for explaining a gripping state of a filament.

FIG. 4 is a nicking characteristic diagram.

[Explanation of symbols]

 1 Suspension Clamp (Clamp) 2 Clamp Main Body 5 Wire Groove 6 Holding Metal 7 Wire Groove L Wire Stroke S Steel Core

[Table 1]

Claims (1)

[Claims] 1. A suspension in which a wire is inserted into a wire groove provided in a suspension clamp main body, and the inserted wire is held by a pressing metal fitting having a wire groove to grip the wire in the suspension clamp main body. In the clamp, a diameter of a circle formed when the two wire grooves are fitted to each other is smaller than a nominal wire groove diameter corresponding to a nominal cross-sectional area determined by the Japanese Industrial Standard of the wire. Suspended clamp.