JPS6218914A - Branching of cable - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a cable branching method for drawing out a branch cable for temporary power supply, etc. from a power distribution cable, particularly a relatively low voltage rubber/plastic insulated cable. .

[Prior art] When it becomes necessary to obtain a bypass power source in an emergency or a temporary power source for construction work from a power distribution cable installed in an underground trench in an urban area, for example, it is necessary to obtain a power source from a nearby manhole or handhole. It is common to have a branch at the end.

When performing such cable branching work, the power distribution cable in the manball or handhole is cut to expose the required length of the conductor, a cable branch body of a predetermined shape is inserted through this, and then compressed using pressure WJIa or the like. A method has been adopted in which the connected V, and furthermore, the connected portion and its vicinity are covered with insulating tape or an insulating cover.

[Problems to be Solved by the Invention] However, in the conventional method, a large working space is required for cutting the conductor of the power distribution cable, attaching the cable branch body, and performing insulation treatment, etc. Moreover, since the shape of the cable branch itself becomes large, it may not be possible to pull out the branch cable in narrow manholes, hand holes, etc. Furthermore, since it is essential to cut the power distribution cable when branching, it is inevitable that the power transmission will be stopped during the work, and therefore, the working hours will be subject to severe restrictions. On the other hand, there may not even be a manhole where a branch cable can be pulled out near a construction site that requires temporary power supply, and in such cases, it is necessary to first find an appropriate branch point with the necessary space. It took a lot of time. In addition, after the temporary power supply is used, it is necessary to remove the branch cable and restore the power distribution cable to its original state, but in this case, it is necessary to cut both ends of the compressed cable branch body, so the power distribution cable In some cases, conductors were missing and reconnection was impossible.

[Means for Solving the Problems] The present invention has been made to solve all of the above problems, and includes a cable gripping portion for connecting to a power distribution cable, a tightening portion communicating therewith, and a lead cable. The present invention provides a cable branching construction method that can easily pull out a branch cable from a power distribution cable or restore the power distribution cable using a cable branch body consisting of the following. In the cable branch body, the cable gripping portion is formed into a cylindrical shape consisting of an upper metal fitting and a lower metal fitting, and a contact is attached on the inner surface of each of the upper and lower metal fittings, and a connecting portion thereof is provided. One side of the is joined by an opening/closing mechanism,
The other sides of the upper and lower fittings to which they are joined are each integrally formed with a tightening portion, which will be described later.

A flexible lead cable for connecting a branch cable is connected to the tip of the tightening part having a tightening mechanism. In the cable branch construction method of the present invention, the above-mentioned cable branch body is opened using the groove as a fulcrum to embrace the power distribution cable, and then the tightening mechanism provided in the tightening part is tightened, and then the cable gripping part The tightening is characterized by covering the outer peripheral surface of the part with an insulator.

[Function] When tightening IiA@ is tightened, the contact on the inner surface of the cable grip part bites into the insulator of the power distribution cable and comes into contact with the cable conductor, thereby establishing an electrical connection with the power distribution cable. Furthermore, since the lead cable is flexible, it can be branched in any direction.

[Example] An example of the cable branching method based on the present invention will be described with reference to the drawings. Figure 3 shows switch 3 in a manhole etc.
0, etc., and the branch is taken from the rising part 25 of the distribution cable 20 connected to this, and a cable branch body 1, which will be described later, is attached to each of the three cores of the cable, The branch cable is pulled out through this. Now, to explain the cable branch body 1 used in this embodiment, as shown in FIG. 1 (a top plan view of the cable branch body) and FIG. 2 (a sectional view of the same), the cable branch body 1 is cylindrical cable grip part 2;
It is formed with the tightening part 3 and the lead cable 4 as main parts, and is formed in a divided shape that can be opened and closed up and down using the opening and closing mechanism 5 as a fulcrum. In other words, the cylindrical cable gripping part 2 consists of an upper metal fitting 21 and a lower metal fitting 22, and the joint portions of the upper and lower metal fittings 21 and 22 on the negative side are each processed into a comb-like shape and engage with each other. are combined. The opening/closing machine fS5 is formed so that the inoculation of the upper and lower metal fittings can be freely crossed by inserting a bolt or pin-shaped metal fitting into the common portion of the mutually engaging portion. In other words, like a hinge, it functions as a fulcrum when opening and closing. On the other hand, on the inner surface of each of the upper metal fitting 21 and the lower metal fitting 22,
For example, blade-shaped contacts 61 and 62 are attached. The contacts 61 and 62 are attached to the inner surfaces of the upper and lower metal fittings by fitting into grooves, but when designing the fitting parts, the contacts may fall off during transportation or work. Please be careful not to do so. In addition, contactor 61.62
This allows them to be replaced to match the conductor size of the distribution cable. Next, the tightening part 3 is attached to the upper and lower metal fittings 2 on the side of the cable gripping part 2 that does not have the opening/closing mechanism @5.
1.22, and in its central part there is a tightening mechanism 7, such as a grooved hole that engages with a tightening port.
A lead cable 4 is connected to the tip thereof. A highly flexible insulated wire is used as the lead cable 4, and as described above, one end thereof is connected to the tightening section 3 by a bolt tightening method, a contact method, or the like. Further, a branch cable is attached to the tip of the lead cable 4, and a branch cable connecting portion 9 such as a terminal or a contactor is formed in advance at the tip.

The cable branching procedure will be explained below with reference to FIGS. 1 to 3. When branching a cable, first select a suitable location for branching at the rising portion 25 of the distribution cable, and peel off the cable sheath at that location using a hand tool or the like to expose the insulator. Next, the cable branch bodies 1 are attached to each of the cables in sequence, but the work procedure for each of the eight branches is the same.

First, the cable branch body 1 is pushed open vertically using the opening/closing mechanism 5 as a fulcrum, the cable is inserted into the cable grip part 2, and then the cable grip part 2 is closed and tightened by tightening the part 3. When the bolts are inserted into the mechanism 7 and tightened gradually, the contacts 61 and 62 provided on the inner surfaces of both the upper metal fitting 21 and the lower metal fitting 22 engage the cable insulator and come into contact with the conductor, creating an electrical connection. can get. In this case, if the cable insulator is heated and softened, the tightening operation becomes extremely easy. Further, when installing the above-mentioned cable branch body, the waterproof effect can be enhanced by applying a mixture such as grease to the surface of the cable insulator before tightening.

After the above work is completed, the outer circumferential surface of the cable gripping part 2 and the tightening part 3 is covered with an insulator 8 such as an insulating cover formed as a divided body and whose joint parts are overlapped. Insulate. Incidentally, the insulator 8 does not necessarily have to be a one-cover type, and may be formed integrally with the cable gripping part 2, the tightening part 3, etc. in advance. On the other hand, since the lead cable 4 uses a flexible insulated wire having a predetermined length, it can be bent in a desired direction. Furthermore, when determining the number of lead cables to be connected, the surface of the lead cables is coated with finger temperature paint, and if a lack of capacity is found through temperature observation, for example, the necessary number is added. Next, regarding the attachment of the branch cable to the tip of the lead cable, as long as the branching work is done while power transmission is stopped, it can be done at any time before or after the cable branch is connected to the distribution cable. .

In addition, in the cable branching method of this embodiment, there is no need to cut the cable conductor, and an electrical connection can be obtained by inserting the contact from above the cable insulator. If you attach a branch cable to the tip of the lead cable in advance and work with insulated tools, insulated protectors, etc., it is possible to branch the cable while it is live.

FIG. 4 shows the state of cable branches in the normal part of the triplex type power distribution cable 20.
In such a case, a plate-shaped separator 4 made of, for example, rubber or plastic is placed in advance before and after the planned branching point of the cable 20.
0 to maintain the expanded state between each core of the cable, and then branching is performed in the same manner as above.

Next, when performing restoration work on the distribution cable after using the temporary power source, first remove the cable branch 1 from the distribution cable, and then
, 62 were press-fitted by wrapping an insulating tape mainly around the outer peripheral surface of the insulator, and then waterproofing that part. Incidentally, instead of wrapping with the above-mentioned insulating tape, it may be covered with heat-shrinkable insulating sheet 1. In the construction method of this example, there is no need to use sleeves for connecting cable conductors as in conventional construction methods, and there is no need to remove cable insulation for branching, so restoration to the original state is extremely easy. . This construction method can also be applied to cable branches for permanent purposes; in such cases, a waterproof layer should be formed by wrapping tape around areas where there is a risk of flooding or submergence. It's better to darken.

[Effects of the Invention] As described above, in the cable branching method of the present invention, a cable branch body consisting of a cable gripping part having a blade-shaped contact on the inner surface, a tightening part and a lead cable is used,
After the distribution cable is inserted into the cable gripping part and tightened, the branched cable can be pulled out very easily and in a short time because the cable is tightened to a length that makes electrical contact with the cable conductor. In addition, with this method, there is no need to cut the conductor of the power distribution cable, so the outer diameter of the branch part becomes smaller, so it is not only possible to pull out the branch cable from a narrow manhole, for example, but also after the temporary power supply has been used. The work of repairing power distribution cables is also extremely easy.

[Brief explanation of the drawing]

FIG. 1 is a top plan view of a cable branch body used in an embodiment of the cable branch construction method based on the present invention, FIG. 2 is an explanatory cross-sectional view of the cable branch body in FIG. 3
The figure is an explanatory diagram showing how the cable branching method of the present invention is applied to a cable rising part, and FIG. 4 is an explanatory diagram showing how the same method is applied to a normal part of a triplex cable. 1: Cable branch, 2: Cable grip, 3: Tightening part, 4: Lead cable, 5: Opening/closing mechanism, 61.62: Contact, 7: Tightening groove, 8: Insulator, 9 Two branches Cable connection part, 20: Cable, 21: Upper metal fitting, 22: Lower metal fitting, 30: Switch, 40: Separator, 61.62: Contact. Agent Patent Attorney Fujio Sato 1960 Patent Application No. 157616
No. 2 Name of invention Cable branching method

Claims (4)

[Claims] (1) A cylindrical cable grip that has an opening/closing mechanism on one side and a contact on its inner surface, and a tightening mechanism that is molded integrally with the cylindrical cable grip. After the power distribution cable is held in the cable gripping part of the cable branch body, which is made up of a clamping part having a clamping part and a lead cable connected to the tip thereof, the contactor is tightened by tightening the clamping part. Engage with the distribution cable from above the insulator, bring the tip of the contact into contact with the conductor of the distribution cable, and further cover at least the outer peripheral surface of the cable gripping part and the tightening part of the cable branch with an insulator. This cable branching method is characterized by: (2) The cable branch construction method according to claim 1, in which the cable branch body is attached while heating and softening the insulator of the power distribution cable. (3) The cable branching method according to claim 1, in which a layer of a waterproof mixture is provided on the outer peripheral surface of the insulator of the power distribution cable. (4) The cable branching method according to claim 1, in which a temperature detection part is provided on the surface of the lead cable to observe the temperature rise in the part, and the number of lead cables attached to the cable branch body is increased as necessary. .