JP3329766B2 - Lifting terminal part of triplex type cable - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of pulling and laying a triplex type cable and a terminal unit used for the same, and more particularly to a method and a terminal unit useful for pulling and laying a triplex type cable in a skyscraper or the like. Things.

[0002]

BACKGROUND OF THE INVENTION Conventionally, a method of pulling and laying a trunk cable for power supply to a high-rise building or the like in the building is as follows.
The retaining bracket system and the messenger-attached system were common. The above-mentioned retaining bracket system is a system in which a terminal branch portion of a cable is fixed for each phase with a special bracket, and is lifted using the bracket. The messenger-attached system is a system in which special processing is performed at regular intervals so that the messenger can be attached along the longitudinal direction of the cable, and the cable is suspended by the messenger.

[0003] However, in the above-mentioned fastening metal fitting system, it is necessary to pull up each single core.
In the case of a wire-type track, three lifting works were required. In addition, since a special metal fitting is attached to each single core when pulling up, there is a problem that the occupied area on the cable rack increases. On the other hand, in the messenger-attached system, since such a cable with a messenger is not a general-purpose product, the cable price is relatively high, and there is an inconvenience that it takes time to manufacture. In addition, it is necessary to remove the messenger wire at the time of laying, and there has been a problem that the working time is lengthened.

Further, as a method of pulling up and laying a triplex type cable in which three-phase single-core cables are twisted, there is a method described in Japanese Patent No. 2826788 previously proposed by the present applicant. In this method, a triplex type cable is twisted and unraveled at its end to form a horizontal line, and these cables are sandwiched and fixed by a band-shaped bracket, and the tension applied to each cable is adjusted to be equal, and then the band-shaped bracket is pulled up and laid. Is what you do. This method is an excellent laying method when laying in a relatively low-rise building or the like.For example, in the case of a 100 m to 300 m class skyscraper, the cable will have a corresponding own weight. If it is pulled up while being sandwiched and fixed from the outside, there is a fear that the sheath may be damaged.

[0005]

Accordingly, the present invention provides a 10
Provided is a method for pulling up a triplex type cable, which can surely lay up a skyscraper of 0m to 300m class or the like and can simplify the processing and pulling up work for the same, and a terminal used for the method. The purpose is to do.

[0006]

[0007]

[0008]

[0009]

[0010]

According to the present invention, a pull-up terminal of a triplex type cable directly connects tip metal fittings to respective cable conductors, screws mounting bolts to these metal fittings, and collectively mounts the mounting bolts to a fixing bar. On the other hand, an insulation reinforcing member is provided at each of the cable end portions, and these insulating reinforcing members are collectively and individually attached to a fixing plate located on the rear surface by respective holding members, and The mounting position on the fixing plate is adjustable.

With such a terminal section, it is possible to form an electrically and mechanically stable terminal by performing only simple terminal operations. In addition, it is possible to prevent the tension from becoming non-uniform due to a cable shift or the like, thereby enabling a stable construction method. In other words, it is practically very difficult to completely match the length of each cable at the end portion of the triplex type cable, and in this state, the end fitting is attached to the fixing bar and pulled up. In this case, the lifting load cannot be evenly distributed.
In view of this, the tip fitting can be adjusted in tension by adjusting the degree of screwing of the mounting bolt, for example, with a spacing adjusting tool. In addition, in the case where the insulation reinforcing member is provided at the terminal portion, the mounting position of each holder to the fixing plate is adjusted so that the mounting position of the insulating reinforcing member can be adjusted in accordance with the adjustment of the mounting position of the tip fitting. It is adjustable.

[0012] In the above case, it is preferable that a suspension support portion is provided on the fixing plate, and that the fixing plate is used as a suspension support plate after pulling up and laying. This makes it possible to efficiently perform the suspending process performed after the pull-up installation.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a partially cutaway front view of one cable terminal portion of a triplex type cable pulling terminal portion according to the present invention, FIG. 2 is a top view thereof, and FIG. 3 is a side view thereof. 4 is an overall view of a triplex type cable pulling terminal section, and FIG. 5 is a side view thereof. In these figures, reference numeral 1 denotes a triplex-type power cable (the twisted portions of these cables are not shown).
0 is stripped off, the cable conductor 11 (shown by a dotted line in the figure), an insulating layer (not shown) made of cross-linked polyethylene or the like extruded thereon, and an outer semiconductive layer 13 , And a shielding layer 14 composed of a copper tape winding layer or the like
Is exposed.

A connection terminal 21 having a male thread 21a at the tip is compression-connected to the cable conductor 11 of the cable 10, and a female thread is screwed into the male thread 21a at the tip of the connection terminal 21. By doing so, the center conductor 22 is connected and fixed. Also, on the tip side of the center conductor 22,
A receiving hole 220 provided with a female screw portion 221 is provided.
20 can be fixed. The receiving hole 220
Is used as a terminal to which the terminal conductor of the branch cable is connected after the completion of the installation.

The connection terminal 21 and the center conductor 22 in this embodiment correspond to the "tip fitting 2 directly connected to the cable conductor 11" in the present invention. The tip fitting 2 may be directly connected to the cable conductor 11, and the form is not limited to the present embodiment, and the form may be appropriately changed according to a laying location, a laying environment, a terminal treatment performed thereafter, and the like. Can be determined.

The portion from the metal fitting 2 consisting of the connection terminal 21 and the central conductor 22 to the exposed portion of the cable outer semiconductive layer 13 is covered with the insulating reinforcing member 3 with a part of the spacer 31 interposed therebetween. The insulating reinforcing member 3 includes an inner semiconductive layer 32 made of semiconductive EP rubber or the like, and an insulating layer 3 made of insulating EP rubber or the like.
3, and an external semi-conductive layer 34 made of semi-conductive EP rubber or the like, for performing insulation reinforcement and electric field relaxation at a terminal portion of the cable 10. The cable shield layer 14 and the end of the cable sheath from the rear end of the insulating reinforcement 3 are covered with a waterproof cover 4 made of EP rubber.

In actually manufacturing the insulation reinforcing member 3, the inner semiconductive layer 32 and the insulating layer 33 are sequentially molded on the central conductor 22, and then the outer semiconductive layer 34 is molded. That is, it can be formed by a molding process integrated with the center conductor 22. In this embodiment, since a gripping force is also applied to the insulating reinforcing body 3 as described later, a cross section made of a stainless steel bending material or the like is used from the viewpoint of mechanically reinforcing the rubber-made external semiconductive layer 34. A reinforcing metal fitting 35 having a rectangular shape is adhered so as to surround three surfaces of the external semiconductive layer 34 having a rectangular cross section.

The insulating reinforcement 3 is held and fixed by two holders 50, 50 supported by a support plate 51. Specifically, the holder 50 is attached adjacent to the reinforcing bracket 35 on both sides of the insulating reinforcing body 3, and the opening of the reinforcing bracket 35 is provided by a protrusion 501 provided on the front end side of the holder 50. By covering the edges and applying pressing force for integration,
The insulating reinforcement 3, the holder 50, and the support plate 51 are integrally fixed.

The terminal portion of each cable 10 subjected to such terminal processing is attached to a fixing bar 6 and a fixing plate 7 as shown in FIG. That is, the tip metal fitting 2 directly connected to the cable conductor 11 is fixed to the fixing bar 6 via the mounting bolt 54, and the insulation reinforcing member 3 is fixed to the holding member 50 by the bolt or the like using the long hole 7 a provided in the fixing plate 7. Each is attached to the plate 7.

More specifically, the tip fitting 2 is attached to a hole 6 provided in the thickness direction of a solid bar 6 made of a rod-shaped metal body.
a is screwed into the female screw 221 provided on the center conductor 21 of each end fitting 2 to collectively connect each phase cable 10 of the triplex to one fixing bar 6. Attach. Note that eyebolts 61 are fixed to both ends of the fixed bar 6, and the triplex type cable is lifted using the eyebolts 61.

As described above, since it is difficult to make the length of the end portion of each cable 10 constant, each of the mounting bolts 54 is screwed into the center conductor 22, and the fixing bar is fixed at the same height level. By attaching to 6,
Excessive tension may be applied to a specific cable because, for example, the horizontality of the fixed bar 6 cannot be maintained during lifting due to the irregular cable length.

Therefore, in the present invention, a mechanism is provided which can adjust the position of attachment to the fixed bar 6 according to the length of each cable 10 in order to evenly distribute the tension. Specifically, the position of the penetration height of the hole 6 a provided in the solid bar 6 of the mounting bolt 54 is adjusted to an appropriate position according to the length of each cable, and in this state, the nut 55 is used to fix the fixed bar 6. Tighten up and down. This makes it possible to keep the fixed bar 6 horizontal and equalize the tension applied to each cable 10.

In view of adjusting the mounting height position of the tip fitting 2 as described above, the insulating reinforcing member 3 already fixed to the terminal portion of each cable 10 and its holder 50 and the fixing plate of the support plate 51 It is necessary to adjust the position of attachment to 7 accordingly. Therefore, in this embodiment, the supporting plate 5 is bolted through the long hole 7a provided in the fixing plate 7.
1 and the fixing plate 7 are fixed, and the mounting position can be adjusted using the long hole 7a.

Next, the actual work of laying a triplex cable using the present invention will be described. First, before pulling up, the end portion of the triplex type cable is untwisted and each cable 10 is subjected to the above-described terminal treatment. Then, the fixing bar 6 and the fixing plate 7 are attached in consideration of equalizing the tension. Next, the triplex type cable is vertically pulled up along the cable ladder at the place where the lifting wire is to be laid on the eyebolt 61 to be laid. At this time, a protective cap or the like may be appropriately provided at the tip of the insulating reinforcement 3 as necessary.

When the pulling up to the uppermost portion is completed, the cable load is dispersed by bundling or fixing to a cable ladder at an appropriate position in the longitudinal direction of the triplex type cable. Thereafter, the fixing plate 7 is suspended and fixed to a structure or the like via a suspension fitting by using the suspension holes 71 provided in the fixing plate 7. Further, mounting bolts 54,
The lifting operation is completed by removing the fixing nut 55 and the fixing bar 6. Thereafter, the female screw portion 22 of the center conductor 22 is formed.
A work such as attaching a conductor connection receptacle to 1 with a special tool and connecting an L-shaped connection portion of a branch cable is performed.

[0026]

According to the method for pulling and laying a triplex type cable of the present invention and the terminal portion used in the same as described above, the pulling tension is applied to the cable conductor itself by directly connecting the tip metal fitting to the cable conductor and pulling it up. Because of the burden, it is possible to pull up and lay triplex cables to skyscrapers. Therefore, the vertical laying of long and large-sized cables in a skyscraper can be lifted and laid at a stretch by hanging at the top at a single point, which is coupled with the adoption of the triplex three-core collective pull-in method. Therefore, it is possible to simplify the laying work and narrow the cable laying space, and as a result, there is an excellent effect that the cost of laying cables in a skyscraper can be greatly reduced.

[Brief description of the drawings]

FIG. 1 is a partially cutaway front view of one cable terminal of a triplex cable pulling terminal according to the present invention.

FIG. 2 is a top view of FIG.

FIG. 3 is a side view of FIG. 1;

FIG. 4 is an overall front view of a triplex type cable pulling terminal according to the present invention.

FIG. 5 is a side view of FIG. 4;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Triplex type cable 10 Cable 11 Cable conductor 2 Tip fitting 21 Connection terminal 22 Center conductor 3 Insulation reinforcement 4 Waterproof cover 50 Holder 51 Support plate 54 Mounting bolt 55 Fixing nut 6 Fixing bar 7 Fixing plate 7a Slot

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-6-98434 (JP, A) JP-A-49-39788 (JP, A) JP-A-55-61224 (JP, A) JP-A-7-98 123562 (JP, A) Hira 5-43719 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H02G 1/06 H02G 3/30

Claims (2)

(57) [Claims] An end fitting is directly connected to each of the cable conductors, a mounting bolt is screwed to the fitting, and the mounting bolt is collectively mounted on a fixing bar. On the other hand, an insulation reinforcing member is provided at each of the cable end portions. The insulating reinforcing members are collectively and individually attached to a fixing plate positioned on the back surface by respective holders, and the mounting positions of the respective holders on the fixing plate are adjustable. Lifting terminal part of triplex type cable. 2. The lifting terminal section of a triplex cable according to claim 1, wherein a suspension support section is provided on the fixing plate, and the suspension section is used as a suspension support plate after pulling up.