JPS6329488B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a crimp connection method for a retaining clamp for retaining and fixing an overhead power transmission line to a steel tower. Steel core aluminum stranded wire used as overhead power transmission line 1
A restraining clamp as shown in FIG. 8 is used to secure the 0 to the tower. The steel core is stripped in steps at its ends, first crimped with a steel clamp having an insulator connection part 6' at one end, and then covered with an aluminum clamp 1' having a jumper terminal 5' and crimped. do. When crimping this aluminum clamp 1', in order to prevent a gap from forming between the steel clamp and the steel clamp after crimping is completed, and to prevent rainwater from entering, connect the steel clamp to the base of the aluminum clamp (on the insulator side). Normally, the clamps are crimped by a so-called positive compression method, in which the ends of the clamps are made to coincide with each other, and the clamps are compressed sequentially from the ends on the insulator side toward the distal end of the retaining clamp. However, according to this positive compression method, the aluminum clamp 1' expands in the direction of the tip of the clamp due to the compression work, and the aluminum wire under the aluminum clamp 1' in particular has an outer layer of wire. As the material stretches, it stretches in the same direction, and when the crimping is completed, there is a risk that a birdcage-like so-called laughter BC as shown in Fig. 1 may occur. For this reason, a reverse compression method has been developed, in which compression is not performed from the base side of the retaining clamp, but instead from the tip side of the aluminum clamp, and some of the methods have been put into practice.
However, even in the case of this reverse compression method, it is necessary to complete the crimping in a state where the end of the steel clamp and the end of the aluminum clamp are securely in contact with each other. Otherwise, a gap may be created at the end, and water may enter through the gap and freeze, destroying the retaining clamp or causing further corrosion. For this reason, the reality is that decompression has conventionally required advanced technology and experience.

The present invention aims to provide a method of decompressing a retaining clamp which eliminates the above-mentioned concerns about accidents and which can be easily carried out by anyone.

The following will be explained based on examples. 1st to 4th
The figure is an explanatory diagram showing the compression splicing method according to the present invention. 10 is a steel core aluminum stranded wire. First, the ends of the steel-core aluminum stranded wire 10 are stripped in steps, and a predetermined length of the steel core 11 is exposed. In this state, the aluminum clamp 1 is previously fitted onto the steel core aluminum stranded wire 10 and shifted to the right in the figure. A steel clamp 2 is then crimped onto the steel core 11 as shown in FIG. This steel clamp 2 is provided with a groove, as shown in FIG. A removable stopper 4 is adapted to be removably engageable. Specifically, a donut-shaped ring made of a plate having a missing part 4a for fitting on one side as shown in FIG. 2 is used, and is press-fitted into the groove 3 from the missing part 4a side for engagement. Can be done. However, the shape is not necessarily limited to this, as long as it is removable and functions as a stopper. Therefore, the position where this groove 3 is set is important. That is, the position of this groove is such that when the aluminum clamp 1 is reversely compressed from the position where it is blocked by the stopper 4, the aluminum clamp 1 expands due to the compression, and when the compression is completed, the steel clamp 2
The outer tapered portion 2a of the aluminum clamp 1 and the inner tapered portion 1a of the aluminum clamp 1 are set at a position where they can be in close contact with each other, that is, specifically, at a position where a distance S shown in FIG. 3 is created.

Next, the compression splicing method according to the present invention will be explained.

When the steel clamp 2 is crimped onto the steel core 11 as shown in FIG. 2, the stopper 4 is inserted into the groove 3.
, pull back the aluminum clamp 1 that has already been fitted, and tighten the stopper 4.
and set at a distance S necessary for proper contact when the compression is completed as shown in FIG. This distance S varies depending on the size and configuration of the wire to be crimped or the configuration of the retaining clamp itself, and is a unique value for each, but it can be easily determined by experiment.
Once you know the value of S, it will be the same for all copies, so you can mass-produce it mechanically.

After setting the distance S as shown in FIG. 3 and fitting the aluminum clamp 1 onto the steel clamp 2, the aluminum clamp 1 is pre-compressed. This preliminary compression is preferably performed at the tip of the aluminum clamp 1 for the purpose of reverse compression. This pre-compression is done by temporarily fixing the aluminum clamp 1 at a distance S to prevent it from slipping during the subsequent compression work, so one-time compression is enough for most purposes, but if necessary. It may be compressed two or three times. After this preliminary compression is completed, the stopper 4 is removed using pliers or the like. In the present invention, this stopper 4
The removal of is one of the feature points. Conventionally, in order to set this distance S, it was not necessary to install a gauge, draw a reference line, or provide a special stopper, but using a gauge requires a special jig for this purpose. Up,
It's too complicated to prepare different items for each size, and it's difficult to set it properly on the guide line, so there's a risk that it will move during compression work, and special stoppers don't allow for that. It is not intended to be removed, but as the aluminum clamp is compressed and elongated, it is rolled up under the gap between the aluminum clamp and the steel clamp. There was a risk that the product would remain in that area.

In the present invention, the stopper 4 is configured to be removable from the groove 3, and a special process called pre-compression is provided, so that the aluminum clamp 1 can be kept in a stable state using the contact force of the stopper 4 during pre-compression. This eliminates the above-mentioned inconvenience that might occur when the stopper 4 is removed and caught in the compressor by leaving a distance S behind, and the stopper 4 is removed before the main compression.

FIG. 4 shows a state in which the main compression is completed, and the arrow in the figure indicates the direction of compression. Since the stopper is not wound up as described above, the outer tapered portion 2a of the steel clamp 2 and the inner tapered portion 1a of the aluminum clamp 1 can be very smoothly brought into close contact and compression can be completed.

Note that when the aluminum clamp 1 is set as shown in Fig. 3 and pre-compressed, the aluminum clamp 1 rotates due to the state of the tool set when compressing with the compression tool, and the jumper terminal 5 is connected to the insulator connection of the steel clamp 2. Part 6
The connecting hole 7 may not have the correct angle and may be crimped in a twisted position. To prevent this, for example, if a rotation preventing device 20 as shown in FIG. can be crimped at the correct angle. That is, 21 and 21 are aluminum clamp-side clamping pieces that clamp the jumper terminal of the aluminum clamp, and 22 and 22 are steel clamp-side clamping pieces that fit and clamp the jumper terminal of the steel clamp, respectively. In addition, respective clamping insertion grooves 23 and 24 of the insulator connecting portion are provided, and a bridging piece 25 bridging these is integrally formed. The rotation prevention device 20 thus formed is used as the fifth
Aluminum clamp 1 and steel clamp 2 as shown in the figure
Fix the bridge between the two clamps so that both clamps do not rotate, and pre-compress. In this way, there is no possibility that the jumper terminal 5 will be compressed in the twisted position as described above. After the preliminary compression is completed, the rotation prevention device 20 is removed in the same way as the stopper, and the main compression is performed. Regarding the external tapered portion 2a of the steel clamp, instead of processing the steel clamp in this way, an aluminum collar 30 as shown in FIG. 7 and a cross-sectional view is fitted onto the steel clamp. It may be formed by In this way, it is easy to form the engagement groove 3 of the stopper 4 on the steel clamp side, and the steel clamp itself does not require any such processing, but an aluminum collar 30 that has undergone the necessary processing is prepared separately. Since the same distance S as described above can be set by selectively fitting them, a more general-purpose decompression connection can be expected.

As described above, with the present invention, the reverse compression connection of the retaining clamp has been simplified and there is no need to rely on experience or intuition, making it extremely common. In terms of size reduction, the present invention has a great effect on this industry.

[Brief explanation of the drawing]

Figures 1 to 4 are explanatory diagrams showing the connection method according to the present invention, Figure 5 is a front view showing the state in which the rotation prevention device is applied, Figure 6 is a sketch showing an example of the rotation prevention device, and Figure 7 is FIG. 8 is a sectional view showing a state in which a stopper is engaged with an aluminum collar used in another embodiment of the present invention, and FIG. 8 is a sketch showing a state in which laughter occurs after the retaining clamp is crimped. 1...aluminum clamp, 2...steel clamp, 3...
Groove, 4...stopper, 5...jumper terminal, 6...
Insulator connection part, 11...steel core, 20...rotation prevention device,
30...Aluminum color.

Claims (1)

[Scope of Claims] 1. In the case where a retaining clamp is crimped by a reverse compression method, in which the outer surface tapered portion of the steel clamp adjacent to the insulator connecting portion and the inner surface tapered portion of the aluminum clamp can be brought into close contact after crimping is completed, and A stopper engagement groove is provided at the end of the wire, which has been fitted with an aluminum clamp in advance and whose end is stripped in steps, so as to leave a distance S that allows the aluminum clamp and the steel clamp to fit snugly together when the reverse compression is completed. A steel clamp is crimped, a stopper is removably engaged with this engagement groove, the aluminum clamp is pulled back, and with the aluminum clamp being stopped by the stopper and leaving the distance S, the aluminum clamp is A reverse compression connection method for a retaining clamp, characterized in that after the aluminum clamp is substantially fixed by preliminary crimping, the stopper is removed and the entire aluminum clamp is reversely compressed. 2. When crimping a retaining clamp by the reverse compression method, in which the outer tapered part of the steel clamp adjacent to the insulator connection part and the inner tapered part of the aluminum clamp can be brought into close contact after crimping is completed, the aluminum clamp is fitted in advance. A steel clamp is crimped to the end of the wire, which has been rolled and the end has been stripped in steps, with a stopper engagement groove that leaves a distance S that allows the aluminum clamp and steel clamp to fit snugly together when reverse compression is completed. , a stopper is removably engaged with this engagement groove, the aluminum clamp is pulled back, and the aluminum clamp is stopped by the stopper and bridges the steel clamp and the aluminum clamp while leaving the distance S. After the aluminum clamp is pre-crimped, and the aluminum clamp is substantially fixed by the preliminary crimping, the stopper and the fixing preventer are fixed. A reverse compression connection method for retaining clamps, which is characterized by removal and reverse compression of the entire body. 3. The reverse compression connection method according to claim 1 or 2, wherein the external tapered portion is formed by an aluminum collar fitted into a steel clamp.