JPH07264744A - Method of enlarging insulation tube - Google Patents

Abstract

PURPOSE:To prevent an insulation tube from bending when the insulation tube is enlarged, by using a guide bar passed in an insulation tube from one enlarging member to the other enlarging member while the enlarging members are inserted by press on each side. CONSTITUTION:An insulating tube (A) covered with a two-piece protective cover 12 is fitted to an opening part of a metallic set member 5. Each metallic enlarging member 2 is put on both end sides of the insulating tube (A). A joining plate 16 in a body with the metallic member 2 is fitted thereto. A guide bar 22 is passed from one metallic member 2 to the other metallic member 2, and thereby both metallic members 2 and the insulating tube (A) are put coaxially in a line. A sliding plate 4 is put nearer by driving a cylinder 3 to insert the enlarging metallic members 2 by press into the insulating tube (A). Since the metallic member 2 goes along the guide bar 22, the metallic member 2 is surely inserted, and the inner diameter of the insulating tube (A) is enlarged without causing a bent part thereof.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of enlarging an insulating cylinder used in a prefabricated type connecting portion.

[0002]

2. Description of the Related Art As a conventional prefabricated type connecting portion, the one shown in FIG. 8 is known. This uses an insulating tube 30 with an inner diameter smaller than the outer diameter of the cable insulator in order to make the connection part compact.
It is formed as follows.

First, the insulating cylinder 30 is expanded in the radial direction using a jig and inserted in advance on the cable sheath 31, and the connecting sleeve 32 is used to connect the cable conductor 33. Next, the insulating cylinder 30 is moved to the center of the connecting portion together with the jig, and the jig is removed so that the insulating cylinder 30 is brought into close contact with the cable insulator 34 by the elasticity of the insulating cylinder 30, and then predetermined processing is performed to form the connecting portion. To do.

The expansion of the insulating cylinder is carried out by inserting cylindrical expanding metal fittings having an outer diameter larger than the inner diameter of the insulating cylinder from both ends of the insulating cylinder. However, since the insulating cylinder is usually made of rubber, both expanding metal fittings are used. There was a problem that the insulating cylinder was bent due to the slight deviation of the core and the expansion metal fitting could not be inserted skillfully. There is also a jig shown in Japanese Patent Application No. 3-58368, which is a type of jig in which an expansion metal fitting is inserted from one end of an insulating cylinder.

[0005]

The present invention has been made to solve such a problem, and is characterized in that when the expansion metal fittings are inserted from both ends of the insulating cylinder, the insulating metal cylinders are inserted from one expansion metal fitting. It is to use a guide rod that passes through to the other expansion metal fitting.

[0006]

EXAMPLES Examples of the present invention will be described below. [Device Configuration] FIG. 1 is a cross-sectional view showing the overall configuration of the expansion device used in the method of the present invention, showing a state in which the expansion metal fittings 2 are press-fitted from both ends of the insulating cylinder A, and FIG. -B, C
The cross-sectional arrow view in -C is shown. This device has two expansion metal fittings 2 built in a case 1 which is almost a rectangular parallelepiped without a bottom surface. It is installed by a cylinder 3, a sliding plate 4, a set metal fitting 5, a sliding rod 6 (see FIG. 2), etc. It is configured to be able to reciprocate oppositely.

(Sliding Plate) First, the sliding plate 4 is for transmitting the driving force of the cylinder 3 to the expansion metal fitting 2, and as shown in FIG. Substantially square plates are arranged facing each other. 2 on each side of each sliding plate 4
By providing a pair of protrusions 8 and fitting the guide protrusions 9 into the guide grooves 9 on the side wall of the case, it is possible to slide along the grooves. In addition, the notch 7 is a place where a connecting plate 16 for joining the sliding plate 4 and the expansion metal fitting 2 is fitted, and a projection 10 that fits into an outer peripheral groove 17 of the connecting plate 16 is formed on the entire circumference of the notch end face. ing.

(Cylinder) Two double-acting cylinders 3 were used to drive the sliding plate 4 as described above. Each cylinder 3 is installed in parallel between both slide plates 4, one cylinder of which is the slide plate 4R on the right side of FIG. 1 and the other is the slide plate of the same left side.
It is connected to 4L and drives the corresponding sliding plate. In this example, a hydraulic cylinder was used.

(Set metal fitting) Two sets of metal fittings 5 are arranged between the sliding plates 4 with a space (see FIG. 1). This is a substantially U-shaped metal fitting (see FIG. 2B) for holding the insulating cylinder A with the opening 5A facing downward, and the above-mentioned three cylinders are fixed to the upper part through a mounting plate 11. When the expansion metal fitting 2 is press-fitted, the insulating cylinder A is provided with a tubular protective cover 12 which is broken into two pieces.

(Sliding bar) Then, eight through holes 13 are formed in both of the set fittings 5 (see FIG. 2B), and each through hole 13 is formed.
The sliding rod 6 is pierced through. The sliding rod 6 is the case 1
The guide groove 9 serves as a guide when the sliding plate 4 slides, and has a length substantially equal to that of the insulating cylinder A. One end of each sliding rod 6 is alternately joined to one of the sliding plates 4, and the other end is open. That is, if one end of a sliding rod is joined to the sliding plate 4R on the right side in FIG. 1 as shown in FIG. 2 (A) or (C), the other end of the sliding rod 6 adjacent thereto is The sliding plate 4L on the left side is joined, and the other sliding rods 6 are sequentially joined in the same manner. Therefore, the set fitting 5 and the cylinder 3 fixed thereto are held by the sliding plate 4 via the sliding rod 6.

(Expansion metal fitting) The expansion metal fitting 2 press-fitted from both ends of the insulating cylinder A by the above-mentioned mechanism has an outer tube as shown in FIG.
It has a double structure consisting of 2A and inner tube 2B. The outer tube 2A has a tapered outer shape as a whole and is formed in two split parts, and its length is almost half that of the insulating cylinder A.

On the other hand, when the inner pipe 2B is press-fitted into the expansion metal fittings, it penetrates through the guide rod 22 which will be described later, so that both expansion metal fittings can be press-fitted on the same axis. The outer tube 2A has a uniform diameter over its entire length and is slightly longer than the outer tube 2A. One end is tapered and the other end is flanged.

Then, in order to facilitate the work of inserting and removing the inner tube 2B, a handle 14 is provided on this flange-shaped end surface. This is one in which a pair of metal rods bent into a mold are attached to face the end surface of the inner tube 2B. In this example, as shown in FIG. 2 (A) or (C), the middle side of the metal rod is curved in an arc shape and attached concentrically with the end face of the inner pipe 2B, and the guide rod 22 is penetrated through the inner pipe 2B. It was configured so as not to become an obstacle when doing.

(Connecting plate) Further, three protrusions 15 (see FIG. 5A) are provided on the outer periphery of the flange-shaped end portion at substantially equal intervals,
It is configured so that it can be connected to the connecting plate 16. The connecting plate 16 is an annular member that connects the expansion metal fitting 2 and the sliding plate 4 and is fixed to the large-diameter side end of the outer tube 2A (see FIG. 3). A groove 17 is formed on the outer peripheral surface along the entire circumference, and the groove 17 is configured to be fitted to the protrusion 10 provided on the notched end surface of the sliding plate.

Further, as shown in FIG. 3, the inner peripheral surface is also provided with a groove 18 extending over the entire circumference thereof. When the connecting plate 16 fixed to the outer pipe 2A is viewed from the axial direction, three notches 19 are formed on the inner peripheral side as shown in FIG. 2A or 2C, and the notches 19 are It extends to groove 18. Therefore, when the inner tube 2B is fitted into the outer tube 2A, and the projection 15 provided on the flange-shaped end portion of the inner tube 2B is fitted into the notch 19 of the connecting plate 16 and appropriately rotated, the projection 15 is caught in the groove 18. , Outer tube 2A (connecting plate 15) and inner tube
2B can be joined together.

(Guide Rod) Further, a guide rod 22 can be cited as a member used when press-fitting the expansion metal fitting 2 (see FIG. 1). This is for penetrating into the insulating cylinder A when press-fitting the expanding metal fitting and holding the insulating material A so as not to bend from the inside thereof. In this example, the length is approximately “length of insulating cylinder + length of expanding metal fitting x 2”. I used the one from Sasa. In addition, the left and right end surfaces of the case in FIG. 1 are provided with notches (not shown) corresponding to the notches 7 of the sliding plate 4 in order to facilitate the insertion and removal of the guide rod 22.

[Operation] Using such a device, for example, a connecting portion of a 33 kv, 400 mm ² , CV cable is formed. Since the outer diameter of the cable sheath is about 51 mm, the inner diameter of the insulating cylinder needs to be expanded to about 55 mm. Further, since the outer diameter of the cable insulator is 42.1 mm, an insulating cylinder having an inner diameter of 40.9 mm before expansion was used. The work procedure is as follows. First, the insulation cylinder A (eg rubber, length 370 mm, outer diameter 60
mm) is covered with a protective cover 12 that has two cracks, and this is shown in FIG.
As shown in FIG.

At this time, the inner tube 2B is attached to the outer tube 2A of the expansion fitting 2.
Is inserted to form an integral unit, and the cylinder 3 is driven to widen the gap between the sliding plates 4. Next, as shown in FIG. 4 (A), the expansion metal fittings 2 are arranged at both ends of the insulating cylinder A, respectively.
The connecting plate 16 integrated with the above is fitted into the notch 7 of the sliding plate 4.

Further, from one of the expansion fittings 2 to the insulating cylinder A
The guide rod 22 is made to penetrate to the other enlargement metal fitting 2 through. As a result, both expansion metal fittings 2 and the insulating cylinder A are located on the same axis.

After the above work, the sliding plate 4 is brought close to the cylinder 3 by driving the cylinder 3, and the expansion metal fitting 2 is press-fitted into the insulating cylinder. At this time, since the expansion metal fitting 2 advances along the guide rod 22, the expansion metal fitting 2 is securely press-fitted into the insulation cylinder A without causing any bending, and the insulation cylinder inner diameter is expanded.

As shown in FIG. 4 (B), since the press-fitting stops when the tips (inner tubes 2B) of the two expansion metal fittings 2 come into contact with each other, in this state, as shown in FIG.
Pull out 22 and inner tube 2B. The guide rod 22 need only be pulled out in either direction from the state shown in FIG. 4 (B), and each inner tube 2B is held by the handle 14 and slightly rotated, and the projection 15 at the flange-shaped end portion 15 is rotated.
It suffices to disengage from the groove 18 on the inner circumference of the connecting plate and pull out.

When the inner tube 2B is pulled out, the outer tube 2A
Since the inner tube 2B is longer than the inner tube 2B, the outer tube 2A is not completely press-fitted as shown in FIG. 5 (A), and there is a space between the outer tubes 2A. Therefore, as shown in FIG. 5 (B), this outer tube 2A
Are further pressed into contact with each other (enlarged diameter of insulating cylinder about 55 mm).

In the above state, the one end insulating cylinder A is removed from the set fitting 5 (of course, the connecting plate 16 is also removed from the sliding plate 4), and the cable is fitted from one end of the cable. Next, the cable conductor is compressed or crimped by the connecting sleeve to perform the cable connecting work, and the cable connecting portion B is aligned with substantially the center of the insulating cylinder A as shown in FIG. Load the set metal fitting 5.

When the sliding plate 4 is driven by the cylinder 3 to pull out the outer tube 2A as shown in FIG.
As shown in (A), the inner diameter of the expanded insulating cylinder A is restored to its original size, and the elastic force causes the insulating cylinder A to come into close contact with the connecting portion B. The expansion metal fitting (outer tube 2A) may be split in two and removed from the cable.

Finally, the protective cover 12 is divided and removed, the tapes 20 at both ends of the insulating cylinder are wound, and the shrinkable tube 21 is covered to complete the connection work.

Although the outer diameter of the insulating cylinder A and the inner diameter of the protective cover 12 are almost the same in each figure, the outer diameter of the insulating cylinder A is often smaller than the outer diameter of the insulating cylinder A. Since there is a space between the cover and the cover, the conventional method is likely to cause the insulating cylinder A to bend.

[0027]

As described above, according to the present invention, when the expansion metal fitting is press-fitted, both expansion metal fittings and the insulating cylinder can be held on the same shaft by penetrating the guide rod, so that shaft shake can be eliminated.
It is possible to prevent bending of the insulating cylinder.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an entire enlarging device used in the present invention.

2 (A, (B), (C) are respectively A- of FIG.
It is a cross-sectional arrow view in A, BB, and CC.

FIG. 3 is a configuration diagram of an enlarged metal fitting used in the method of the present invention.

4A and 4B are explanatory views showing the operation procedure of the expansion device, in which FIG. 4A shows the expansion fitting immediately before being press-fitted, and FIG.

5A and 5B are explanatory views showing an operation procedure of the enlargement device, FIG. 5A shows a state where the inner pipe and the guide rod are pulled out, and FIG. 5B shows a state where the outer pipe is press-fitted.

6A and 6B are explanatory views showing an operation procedure of the enlargement device, FIG. 6A shows a cable connection portion insertion time, and FIG. 6B shows an outer tube extraction time.

7A and 7B are explanatory views showing an operation procedure of the enlargement device, in which FIG. 7A shows the outer tube withdrawal completed, and FIG. 7B shows the cable connection part completed.

FIG. 8 is an explanatory diagram of a cable connecting portion.

[Explanation of symbols]

1 Case 2 Enlargement fitting 2A Outer tube 2B Inner tube 3
Cylinder 4 Sliding plate 5 Set metal fitting 5A Opening 6 Sliding rod 7 Notch
8 Protrusion 9 Guide groove 10 Protrusion 11 Installation plate 12 Protective cover
13 Through hole 14 Handle 15 Protrusion 16 Connecting plate 17 Groove 18 Groove 19 Notch 20
Tape 21 Shrink tube 22 Guide rod A Insulation tube B Connection part 30 Insulation tube 31 Plastic sheath 32 Sleeve 33 Cable conductor 34 Insulator 35 Power cable 36 External semiconductive layer 37 Conductive layer 38
Semi-conductive layer 39 Tape winding layer 40 Insulating tape 41 Waterproof tape
42 heat shrink tube

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshimitsu Saito 1-3-3 Shimaya, Konohana-ku, Osaka City Sumitomo Electric Industries, Ltd. Osaka Works

Claims (1)

[Claims] 1. A method for press-fitting a cylindrical expansion metal fitting from both ends of the insulating cylinder to expand the inner diameter of the cable connecting portion so as to cover the outer circumference of the cable connection portion closely. At this time, the guide rod is penetrated from one expansion metal fitting to the other expansion metal fitting to the other expansion metal fitting, the expansion metal fitting is press-fitted into the insulation cylinder, and then the guide bar is pulled out, and then the cable connecting portion is arranged in the insulation cylinder. A method for enlarging an insulating cylinder, which is characterized in that