JPH06311618A - Method and device for stripping power cable - Google Patents

Abstract

PURPOSE:To enhance the electric characteristics of a power cable having an easy strip semiconductor layer after molding. CONSTITUTION:When a slit S is made on a predetermined circle in an outer semiconductor layer 35 of a power cable 31 and then a spiral slit S is made up to the end 35a of the outer semiconductor layer 35, a V-cut is made with the slit S on the circle as a center. Since the residual end part of the outer semiconductor layer 35 is prevented from biting an insulator 34 at the time of semiconductive molding and the air gap is eliminated at the time of winding a semiconductive molding tape, electric characteristics can be enhanced after semiconductive molding.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power cable coating stripping method and a stripping apparatus thereof, and more particularly to a power cable coating stripping method having an easy strip type semiconductive layer and a stripping apparatus thereof.

[0002]

2. Description of the Related Art Conventionally, a CV cable (crosslinked polyethylene power cable) has been used as a large power cable for transmitting a high voltage current. In the CV cable, as shown in FIG. 9, a conductor 32 is covered with an insulator 34 made of crosslinked polyethylene via an inner semiconductive layer 33, and further covered with a sheath 37 via an outer semiconductive layer 35 and a shielding copper 36. Is. The inner semi-conducting layer 33 and the outer semi-conducting layer 35 alleviate the potential gradient between the surface of the conductor 32 and the inner wall of the outermost sheath 37 (insulating part), and maintain a uniform concentric cylindrical electric field. There is. The sheath 37 has a role of enclosing the outer semiconductive layer 35 with an insulating portion mainly made of plastic and holding a voltage.

To connect such a CV cable 31, first, the sheath 37 and the shielding copper 36 are removed, and then the outer semiconductive layer 35 is peeled off to expose the insulator 34. To peel off the outer semiconductive layer 35, a peeling device dedicated to peeling off the cable coating is used. As shown in FIG. 10A, the cutting operation of the outer semiconductive layer 35 is performed by cutting a slit S on a predetermined circumference of the outer semiconductive layer 35 with a slitting tool (blade) provided in a peeling device or the like. No
At this time, the slit S is cut so that the depth thereof does not exceed the thickness of the outer semiconductive layer 35, that is, the insulator 34 is not scratched. After the slit S is cut on the circumference of the outer semiconductive layer 35, the slit S is spirally cut toward the end portion 35 a of the outer semiconductive layer 35. Also at this time, the depth of the slit S is set so that the insulator 34 is not scratched.

A cutter knife or a driver is inserted into the end of the outer semiconductive layer 35 having the slits S formed in a spiral shape, and FIG.
As shown in (b), the outer semiconductive layer 35 is slowly peeled off in a spiral shape. Then, a slit S is further cut on the circumference of the insulator 34 to remove it, and the conductor 32 is exposed to expose the CV.
The cable 31 can be connected.

[0005]

However, when the CV cable 31 is subjected to the semiconductive molding, the residual side end portion 35b of the outer semiconductive layer 35 is an edge as shown in FIG. 11A. When the molding semiconductive tape 38 was wound around the outer semiconductive layer 35, an air gap G was formed in the vicinity of the residual side end portion 35b. Further, as shown in FIG. 11B, when the mold semiconductive tape 38 is heated to bring it into close contact with the insulator 34, a CV of 660 KV or more is obtained.
In the cable 31, the residual side end portion 35b sometimes bit into the insulator 34.

As described above, since the air gap G is generated or the residual side end portion 35b bites into the insulator 34,
There is a problem that the electrical characteristics of the CV cable 31 are deteriorated.

[0007]

An object of the present invention is to solve such conventional problems, and to improve electric characteristics after molding, which is a method of connecting a power cable having an easy strip type semiconductive layer. An object of the present invention is to provide a power cable coating peeling method and a peeling apparatus for the same.

[0008]

SUMMARY OF THE INVENTION A power cable coating stripping method of the present invention which achieves such an object is a coating for stripping one coating layer of a plurality of coating layers formed on a conductor of a power cable. In a power cable coating stripping method in which a notch is cut on the circumference of a layer and then spirally cuts to the end surface of one covering layer, the notch on the circumference of one covering layer is cut over a certain range. The cutting is performed in a concave shape in the thickness direction of the coating layer.

The power cable sheath stripping device of the present invention is a power cable sheath stripping device that cuts one coating layer of a power cable having a plurality of coating layers, and is fixed to the frame and the same position of the frame. A processing means for forming a notch or a concave cutting groove on the circumference of the one coating layer, and a plurality of spindles provided with a threaded portion and fixed at symmetrical positions of the frame about the processing means, The pressing means includes a pressing member that is inserted into the plurality of support shafts and that is screwed into the screwing portion, and an elastic member that is provided in the pressing means and that presses the power cable by the processing means.

[0010]

[Function] In order to easily peel off one of the plurality of coating layers, a cut is made on the circumference of the one coating layer and then a spiral cut is made to the end surface of the one coating layer. At this time, the one coating layer is cut into a concave shape in the thickness direction of the one coating layer over a certain range of the notch on the circumference.

As a result, the end portion of the coating layer can be cut into the insulator during molding and the air gap when the semiconductive tape for molding is wound can be eliminated, so that the electrical characteristics after molding can be improved. Can be improved. Further, when making a notch in the one coating layer, or when cutting into a concave shape in the thickness direction of the one coating layer, the notch along the shape of the power cable by the pressing force of the pressing means inserted into the plurality of support shafts, Since cutting can be performed, a stable depth of cut can be obtained.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the power cable coating stripping method and stripping apparatus of the present invention will be described below with reference to the drawings. As shown in FIG. 1, the power cable coating stripping apparatus of the present invention includes a frame 5 having a stopper hole 5a and a sliding hole 5b, and an external semiconductive layer which is inserted into the stopper hole 5a and forms a CV cable 31. A taper making holder 2 which is a processing means for forming a concave groove having a taper bite (cutting tool) 9 for cutting 35, and a stepped shaft 4 which is a spindle inserted into the sliding hole 5b. , Inserted into the stepped shaft 4, presses the CV cable 31 against the taper cutting tool 9 and bites the taper cutting tool 9 into the outer semi-conductive layer 35. Spring holder 15 provided with a spring 14 that is an elastic member
It consists of and.

The stopper hole 5a of the frame 5 is formed in the frame 5
The sliding hole 5b is formed at a symmetrical position with respect to the stopper hole 5a. As shown in FIG. 2, the taper forming holder 2 has a cylindrical shape and is divided into two parts, which are fixed by bolts 11 and 12 to be integrated. The taper bite 9 fixed to the taper creation holder 2 is fixed by a set screw 13 while being sandwiched by a guide plate 10 in a recess provided in the taper creation holder 2. The shape of the taper cutting tool 9 is to form a taper surface on the circumference of the outer semiconductive layer 35.
As shown in FIG. 3, the V-cut is symmetrically formed, and a sharp protrusion is provided at the tip of the V-cut so that the V-cut can be easily cut into the outer semiconductive layer 35. On the other hand, the guide plate 10 is for adjusting the cutting amount of the taper bite 9, and the taper bite 9 is adjusted by a screwdriver or the like from the cutting edge adjustment window 2a provided in the taper making holder 2.
Adjust the height of the blade edge of.

As shown in FIG. 4, a specific adjusting method is as follows. The guide plate 10 is provided on the upper surface 16a of the cutting edge adjusting jig 16 according to the thickness of the outer semiconductive layer 35 of the CV cable 31 to be cut.
And the taper bite 9 from the blade tip adjusting window 2a by a screwdriver or the like to the recess 16 provided in the blade tip adjusting jig 16.
Adjust until the blade edge of the taper cutting tool 9 contacts the bottom surface of b. After the adjustment, the taper bite 9 and the guide plate 10 are fixed with the set screw 13.

On the other hand, a conventional slit making holder 20 as shown in FIG. 5 is used as a processing means for cutting a circumferential slit or a spiral slit in the outer semiconductive layer 35. Since the slit forming holder 20 has a cylindrical shape having the same diameter as the taper forming holder 2, it can be inserted into the stopper hole 5a similarly to the taper forming holder 2. This slit holder 2
A slit cutting blade 20b for cutting a slit is fixed to the front end portion of 0, and a cutting direction knob 20a for changing the direction of the cutting edge of the slit cutting blade 20b is provided at the rear end portion. .

Further, the taper forming holder 2 and the slit forming holder 20 are provided with notches so as to stop at predetermined positions when inserted into the stopper holes 5a. After the insertion, the taper making holder 2 or the slit making holder 20 described later is fixed to the frame 5 with the swivel nut 8. Also, the stepped shaft 4 has a sliding hole 5
After inserting into b, it is fixed to the frame 5 with the butterfly nut 7.

In the pressing metal fitting 3, the pressing plate 3a is bent in a dogleg shape so that the CV cable 31 can be pressed at two points, and the pressing plate 3a is brought into contact with the CV cable 31. A sliding plate 3c made of Teflon, which is a sliding material, is fixed to the CV cable 31 so that the power cable coating peeling device 1 can smoothly slide on the CV cable 31. Further, when the pressing fitting 3 is inserted into the stepped shaft 4 and moved up and down, the pressing plate 3a may be caught on the stepped shaft 4 because it is a thin plate. Therefore, the guide member 3b for reinforcement is pressed by the pressing plate 3a. It is fixed to. When the pressing metal fitting 3 is inserted into the stepped shaft 4, the pressing metal fitting 3 is locked at the stepped portion.

In order to press the CV cable 31 with the pressing metal fitting 3 as described above, the pressing metal fitting 3 is fixed with a butterfly nut 6 which is a screw member through a spring holder 15 having a spring 14 and a step having a threaded portion. It is locked to the attached shaft 4.
By adjusting the spring holder 15 provided with the spring 14 with the hinge nut 6, the pressing force on the CV cable 31 can be adjusted.

A method of working the cable coating stripping device 1 thus constructed will be described below. To connect the CV cable 31 as shown in FIG.
7. The shielding copper 36 is removed to expose the outer semiconductive layer 35. After the exposure, as shown in FIG. 6A, the outer semiconductive layer 3 is exposed.
Make slits S on the circumference of 5 and spirally.
In order to cut such a slit S, the slit making holder 20 is inserted into the stopper hole 5a of the frame 5 of the cable coating stripping device 1 until it is stopped, and is fixed to the frame 5 with the butterfly nut 8. The cutting direction knob 20a provided on the slit making holder 20 is set at a position where the slit S can be cut on a predetermined circumference.

At a predetermined position of the CV cable 31 where the outer semiconductive layer 35 is exposed, the cable coating stripping device 1 having the slit making holder 20 fixed thereto is fitted. After fitting, while tightening the butterfly nut 6, the outer semiconductive layer 35
Bite into the slit cutting blade 20b provided in the slit making holder 20. At this time, the bottom surface of the guide member 3b and the stepped shaft 4 are secured so that a uniform pressing force can be secured.
Make a gap with the step at a predetermined interval.

While holding the slit making holder 20 lightly, the cable coating stripping device 1 is rotated from the front side to the upper side, and the slit S is cut on a predetermined circumference. At this time,
A stable slit depth can be obtained by the pressing force of the spring 14 provided in the spring holder 15. After the cutting is completed on the predetermined circumference, the cutting direction knob 20a is set at a position where the spiral slit S can be cut. Similarly to when the slit S is cut on a predetermined circumference, when the cable coating stripping device 1 is rotated upward from the front while holding the slit making holder 20 lightly,
While performing the spiral cutting in the direction of the end portion 35a of the outer semiconductive layer 35, the cable coating stripping device 1 moves to complete the spiral cutting. Since the insulator 3 covered with the outer semiconductive layer 35 is required to have high insulation characteristics and low loss, when the slit S is cut in the outer semiconductive layer 35, the insulator 3 having a thickness of 1 μm is cut. Do not scratch it.

After cutting the spiral slit S, the butterfly nut 8 is loosened to remove the slit making holder 20. The taper making holder 2 in which the cutting amount of the taper cutting tool 9 has been adjusted by the cutting edge adjusting jig 16 is inserted into the stopper hole 5a of the frame 5 until it is stopped, and is fixed to the frame 5 by the butterfly nut 8. The cable coating stripping device 1 is fitted so that the sharp protrusions provided on the taper cutting tool 9 are aligned with the positions of the circumferential slits S cut in the outer semiconductive layer 35. After fitting, tighten the butterfly nut 6 and bite the taper bite 9 until the guide plate 10 fixed to the taper making holder 2 comes into contact with the outer semiconductive layer 35. While holding the slit making holder 20 lightly, the cable coating stripping device 1 is rotated from the front side to the upper side, and the V-cut taper surface V as shown in FIG. 6B is cut over a certain range. At this time, a stable taper depth can be obtained by the pressing force of the spring 14 provided in the spring holder 15.

By inserting a cutter knife or a screwdriver into the end of the outer semiconductive layer 35 having the slit S formed in a spiral shape, as shown in FIG.
As shown in (c), the outer semiconductive layer 35 is slowly peeled off in a spiral shape. Then, a slit is further cut on the circumference of the insulator 34 to remove the insulator 34 of a predetermined length, and a semiconductive molding process is performed. In the semi-conductive molding process, as shown in FIG. 7, the semi-conductive tape for molding 38 is wound around the residual side end portion 35v of the outer semi-conductive layer 35 and the insulator 34, and the semi-conductive tape for molding 38 is insulated. It is heated to bring it into close contact with 34. At this time, the remaining end 35v is V
Since it is on the valley side of the cut-shaped taper surface V, the external force at the time of semiconductive molding is dispersed on the taper surface V. As a result, it is possible to prevent the residual side end portion 35v from biting into the insulator 34. Further, since the residual side end portion 35v is formed to be very thin, no air gap is generated even when the molding semiconductive tape 38 is wound around the residual side end portion 35v and the insulator 34.

Incidentally, in this embodiment, the convex shape which is the shape of the taper cutting tool 9 is formed into a V-cut which is symmetrical to the left and right, but the present invention is not limited to this, and it is asymmetrical as shown in FIG. 8A. You may form in V cut 9A and R cut 9B as shown in FIG.8 (b). Further, since a sharp protrusion capable of cutting the slit S is formed at the tip of the taper bite 9, the external semiconductive layer is formed by using the taper making holder 2 to which the taper bite 9 is fixed. 35
At the same time as forming the V-cut tapered surface V, the slit S is cut on the circumference, and then the spiral slit S is cut by the slit cutting blade 20b provided in the slit making holder 20. Good.

[0025]

As is apparent from the above embodiments, the power cable coating stripping method and stripping apparatus of the present invention are
In order to easily peel off one of the plurality of coating layers, when making a cut on the circumference of the one coating layer and then making a spiral cut to the end surface of the one coating layer, By cutting into a concave shape in the thickness direction of one coating layer over a certain range of the notch on the circumference of the coating layer, it is necessary to cut into the insulator at the end of the coating layer when molding the power cable or to mold it. Since it is possible to eliminate the air gap that occurs when winding the semi-conductive tape for winding, it is possible to improve the electrical characteristics of the power cable after the molding process, and it is also possible to improve the electrical characteristics of the pressing means inserted into a plurality of spindles. Since it is possible to perform cutting and cutting along the shape of the power cable by the pressing force, it is possible to obtain a stable cutting amount.

[Brief description of drawings]

1A and 1B are views showing a power cable coating stripping device of the present invention, in which FIG. 1A is a front view and FIG. 1B is a side view.

FIG. 2 is a detailed view showing the parts of the power cable coating stripping device of the present invention.

FIG. 3 is a detailed view showing a taper bite used in the power cable sheath peeling device of the present invention.

FIG. 4 is an explanatory view showing adjustment of a cutting amount of a taper cutting tool.

FIG. 5 is a detailed view showing parts used in the power cable sheath stripping device of the present invention.

6A and 6B are views showing a method for peeling off a power cable according to the present invention, wherein FIG. 6A is an explanatory view showing a method of cutting a slit on a predetermined circumference and a spiral slit, and FIG. 6B is a V-cut taper surface. It is explanatory drawing which shows the method of cutting, (c) is explanatory drawing which shows the method of peeling a semiconductive layer after cutting and cutting.

FIG. 7 is an explanatory view showing a state of semiconductive molding.

8A and 8B are views showing another embodiment of the taper cutting tool used in the power cable coating stripping device of the present invention, FIG. 8A is a detailed view of an asymmetric V-cutting taper cutting tool, and FIG.
Detailed view of taper bite for cutting.

FIG. 9 is a cross-sectional view of a power cable.

10A and 10B are diagrams showing a conventional method for peeling off a power cable coating, wherein FIG. 10A is an explanatory diagram showing a method for cutting a slit on a predetermined circumference and a spiral shape, and FIG. 10B is a method for peeling a semiconductive layer after cutting. Explanatory diagram showing a method of doing.

FIG. 11 is an explanatory view showing a state of semi-conductive molding,
(A) is explanatory drawing of the power cable which wound the semiconductive tape for molds, (b) is explanatory drawing which shows the state of the power cable when the power cable wound with the semiconductive tape for molds was heated.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Power cable coating stripping device 2 ... Taper making holder 2a ... Blade edge adjusting window 3 ... Pressing metal fitting 3a ... Pressing plate 3b ... Guide member 3c ... Sliding plate 4 ... Stepped shaft 5 ... Frame 5a ... Stopper hole 5b ... Sliding hole 6, 7, 8 ... Butterfly nut 9 ... Taper bite 10 ... Guide plate 11, 12 ... Bolt 13 ... Set screw

Claims (2)

[Claims] 1. A cutout is formed on the circumference of one coating layer for peeling off one coating layer of a plurality of coating layers formed on a conductor of a power cable, and from the end surface of the one coating layer. In the method for peeling off a power cable coating in which a spiral cut is made, the cut on the circumference of the one coating layer is cut into a concave shape in the thickness direction of the one coating layer over a certain range. A method for stripping a power cable coating. 2. A power cable coating stripping device for cutting one coating layer of a power cable having a plurality of coating layers, the frame and a circumference of the one coating layer fixed at the same position of the frame. A plurality of spindles provided with a machining means for forming a notch or a concave cutting groove on the frame, and a screwing portion, and fixed to symmetrical positions of the frame about the machining means, and the plurality of spindles. Power cable comprising a pressing means having a screwing member that is inserted into the screwing portion and screwed into the screwing portion, and an elastic member that is provided in the pressing means and that presses the power cable by the processing means. Coating stripping device.