JPH1023650A - Machine direct-coupled cable head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate the large current application with a compact construction by a method, wherein a plug fixed to the tip of a cable conductor is inserted into a plug insertion part which is opened downward with a multicontact contactor therebetween. SOLUTION: An inner conductor 2 and a shielding metal fitting 30 are molded and buried in the insulating bushing 1 of a cable head. The shielding metal fitting 30 is electrically connected to the inside of the inner conductor 2 with a connection conductor plug 40, which is detachably attached to a plug insertion hole 1a. The connection conductor plug 40 is pressed against the inner conductor 2 or the plug insertion parts 21 and 32 of the shielding metal fitting 30 with multicontact contactors 41 and 42, such as multiram bands, etc., which are fitted to the trenches in the cylindrical outer circumference on both the left and right end neighborhoods of the connection conductor plug 40. A cable conductor 11a is inserted into the plug insertion part 34 of the shielding metal fitting 30 and connected to the shielding metal fitting 30 with a multicontact contactor 37 and electrically connected to a high-voltage conductor on the machine side. As a result, the overall construction can be made compact, and a large current can be applied.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device-directly connected cable head used when a power cable is directly connected to a sealed electric device.

[0002]

2. Description of the Related Art Recently, electric devices such as switchgears and transformers have been housed in an equipment case together with an insulating medium such as gas or oil from the viewpoint of reducing the size of land at a substation and improving the reliability of power transmission and distribution. Although sealed electric devices have been widely adopted, when a power cable is connected to these sealed electric devices, a device directly connected cable head is used. Since the high-voltage part of enclosed electrical equipment is not exposed to the outside of the equipment case, especially in the case of a power cable line whose both ends are directly connected to the enclosed electrical equipment, the equipment case must be It was necessary to remove gas and oil from the inside, and to attach an adapter for power application, and there was a problem that it took a lot of man-hours and time. In order to solve such a problem, a T-shaped cable head having a disconnection function as shown in FIG. 5 has been developed and put to practical use.

In FIG. 5, an inner conductor 2 and a shield 3 are embedded and molded in an insulating bushing 1. The inner end of the inner conductor 2 and the shield 3 are electrically connected by a detachable connection conductor plug 4. A pre-molded insulator 5, shielding electrodes 6 and 7 molded at inner and outer ends thereof, and a spring formed on a tapered opening of the insulating bushing 1 on a surface opposite to the inner conductor 2. An insulating plug 10 consisting of a lid 9 and a cover 9 is mounted. Cable conductor 11 of power cable 11
The cable terminal 12 crimped and fixed to the end of the shield a is electrically connected to the shield 3 via a contact 13 such as a tulip contact in a conductive sleeve 3 a extending below the shield 3. Bushing 1
Power cable 11
The stress cone 14 is mounted on the insulator 11b.

[0004] The T-shaped cable head having such a structure is as follows.
Three of the inner conductors 2 of each T-shaped cable head protrude from the inside of the insulating bushing 1 in the equipment case, and are mounted adjacent to the case side plate 15 of the sealed electrical equipment such as GIS. (Not shown). Therefore, in a normal use state, the power from the power cable 11 is supplied to the high-voltage conductor on the device side through the cable conductor 11 a, the cable terminal 12, the contact 13, the shield 3, the connection conductor plug 4, and the inner conductor 2. Is done. An insulating plug 1 is provided in the opening of the insulating bushing 1.
0 and a stress cone 14 are attached to maintain the required dielectric strength.

[0005] When performing a DC withstand voltage test of the power cable 11 directly connected to the sealed electric device in this manner,
To prevent DC voltage from being applied to the electrical equipment,
As shown in FIG. 6, the insulating plug 10 and the conductor plug 4 for connection are removed from the power supply port, and the end of the test lead cable 17 is connected. In this case, a disconnecting insulating plug 16 is attached in place of the connecting conductor plug 4, and a distal end of a test lead cable 17 and a stress cone 18 are inserted in place of the insulating plug 10, and a distal end of the cable conductor 17 a is inserted. Contact 19 adhered to
Is electrically contacted with the inner surface of the shield 3 via a spring. In this state, when a test power supply is connected to the other end of the test lead cable 17 and a predetermined DC voltage is applied, the test voltage is changed to the cable conductor 17 as shown by an arrow in FIG.
a, the contact 19, the shield 3, the contact 13 and the cable terminal 12 are applied to the cable conductor 11a of the cable under test, but the inner conductor 2 is cut off from the shield 3 by the disconnecting insulating plug 16. Therefore, no voltage is applied to the high-voltage conductor on the sealed electrical device side. As described above, the use of the T-type cable head with the DC power application function allows the sealed electric device to be opened without opening the case, treating the insulating medium, and applying a DC voltage to the device side.
DC withstand voltage test of cable directly connected to equipment can be performed.
Other tests can be performed efficiently.

[0006]

However, in the T-shaped cable head having the above-described structure, a finger-type contact is used to connect the shielding bracket 3 to the cable terminal 12, so that a large current is supplied. Therefore, there has been a problem that it is not easy to adapt to the withstand current test, and the overall dimensions and weight are also large. Further, if a pulling force acts on the cable, the cable may fall off. However, there has been a problem that the structure and mounting of the dropout prevention mechanism for preventing the dropout are not easy. The present invention solves such a conventional technical problem, and is compact and capable of conducting a large current, and even if a pull-out force acts on the cable, the cable is directly connected to a device without the risk of accidentally falling off. It is an object to provide a head.

[0007]

According to a first aspect of the present invention, there is provided a direct-connecting cable head in which an inner conductor and a shield are molded in an insulating bushing. A plug insertion portion, the insulating bushing is formed with a tapered opening that opens on the axis of these plug insertion portions, and the shielding fitting has an upper surface of the plug insertion portion that opens downward,
A connection hole is formed between the plug insertion portion and the lower surface of the plug insertion portion that opens laterally, and the plug fixed to the tip of the cable conductor of the power cable is opened downward through a multi-contact type contact. And a fastening bolt inserted into the connection hole and screwed and fixed to a cable conductor inserted into the plug insertion portion opening downward.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS According to the present invention, the use of a multi-contact type contact makes the whole compact, adapts to the application of a large current, and has an insulating material necessary for the construction of an insulating bushing. Weight and cost can be greatly reduced. Further, the structure of the dropout prevention mechanism and the mounting operation are also facilitated. In the cable head directly connected to equipment of the present invention, the connecting hole is a stepped hole, the large diameter portion of which is opened on the cylindrical lower surface of the plug insertion portion which opens laterally, and the retaining bolt inserted through this connecting hole. May be housed in the large-diameter portion, and the vicinity of the lower end of the retaining bolt may be screwed to a nut attached to a wedge fitting fixed to the cable conductor side. In this case, since the heads of the retaining bolts opening laterally do not protrude from the plug insertion portion, there is no hindrance to the mounting of the power application lead cable and the like.

In the present invention, a plug insertion hole is formed between the inner conductor in the insulating bushing and the shielding metal, and the connection conductor plug or the disconnection insulating plug is selectively mounted in the plug insertion hole. Can be Therefore, in a DC power application test or the like of the power cable, by mounting the disconnection insulating plug, it is possible to prevent the DC voltage from being applied to the high-voltage conductor on the device side. In the present invention, a fastening ring is screwed to a plug insertion portion opened on a surface opposite to the plug insertion portion opened to the side of the shielding metal, and the fastening ring is connected to a conductor plug for connection or an insulating plug for disconnection. Can be connected by a connecting bolt loosely fitted to the tightening ring. In this case, when the tightening ring is pulled out by twisting, the connecting conductor plug or disconnecting insulating plug is also pulled out together, but since the connecting bolt is loosely fitted to the tightening ring, the connecting conductor plug or disconnecting plug is disconnected. The insulation plug is pulled out without rotation. Thus, it is possible to prevent the multi-contact type contactor attached to the connection conductor plug from being damaged or damaged by the plug insertion portion.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. In these figures, the same parts as those in FIGS. 5 and 6 are denoted by the same reference numerals, and description thereof will be omitted unless necessary. FIG. 1 is a longitudinal sectional view of an embodiment of a cable head directly connected to equipment of the present invention, and FIG. 2 is a side view of the cable head with its insulating plug removed. In these figures, an inner conductor 2 and a shield 30 are embedded and molded in an insulating bushing 1. The shielding bracket 30 is on the right side (up, down, left, and right directions are represented in the states of FIGS. 1 and 3).
A plug insertion part 31 having a large diameter is provided on the left side, and a plug insertion part 32 having a slightly smaller diameter is provided on the left side. A large-diameter plug insertion portion 34 is provided in a short conductive sleeve 33 extending downward. A small-diameter plug insertion portion 21 is formed at the inner end of the internal conductor 2, and a tapered plug insertion portion whose diameter decreases toward the plug insertion portion 21 is inserted between the small-diameter plug insertion portion 21 and the plug insertion portion 32. A hole 1a is formed. Shield 30 and inner conductor 2
Are electrically connected to each other by a connection conductor plug 40 removably inserted into the plug insertion hole 1a. The connecting conductor plug 40 has a cylindrical shape in the vicinity of the right end and the left end, and a tapered shape in the middle corresponding to the plug insertion hole 1a, and is mounted in a cylindrical outer peripheral groove near both right and left ends. The inner conductor 2 or the shielding metal 30 is formed by multi-contact type contacts 41 and 42 such as a multi-lamb band.
Are in pressure contact with the plug insertion portions 21 and 32. A tightening ring 51 is screwed into the screw portion 32 a on the inlet side of the plug insertion portion 32, and the tightening ring 51 and the connecting conductor plug 40 are connected by a connecting bolt 52 loosely fitted to the tightening ring 51. .

The tightening ring 51 is, as shown in FIG.
A threaded fastening portion 51a is provided on the outer surface, and a pressing portion 51b protruding to the left and inserted into a recess formed in the connection conductor plug 40 is provided, and a bolt insertion hole 51c is formed at the center thereof. A plurality of boss holes 51d for inserting a detachable tool are formed around the bolt insertion hole.
In the right half of the bolt insertion hole 51c, a reverse screw 51e for attaching a drawing tool is cut. The left end surface of the pressing portion 51b is reduced in diameter to a smaller diameter than its head portion 52a so that the bolt 52 does not come off. An insulating plug 10 is attached to a tapered opening 1c of the insulating bushing 1 which opens on a surface opposite to the inner conductor 2. As shown in FIG. 3, a conductive plug 36 is fitted and fixed to a distal end of the cable conductor 11 a of the power cable 11 via a wedge fitting 35. The plug 36 is pressed against the plug insertion portion 34 by a multi-contact type contact 37 such as a multi-ram band mounted in a groove on the outer periphery thereof, and electrically connects the cable conductor 11a and the shielding metal 30. .

The cable conductor 11a and the shield 30
A drop-off prevention mechanism is attached between the two. As shown in FIG. 3, the drop-out prevention mechanism includes a connection hole 6 provided in the lower surface of the shield fitting 30 near the left end of the plug insertion portion 31.
1, a nut 62 fixed to the wedge fitting 35 at the tip of the cable conductor 11a, and a retaining bolt 63 connecting the nut 62 and the connection hole 61. Connection hole 6
Reference numeral 1 denotes a stepped hole having a large-diameter portion having a size capable of completely storing the head 63a of the retaining bolt 63.
A hexagonal hole 63b for mounting a wrench is formed in the head 63a of the third. The nut 62 includes a sleeve 62 a having a smaller diameter than the through hole 35 a formed on the top surface of the wedge fitting 35, and a flange 62 b having a larger diameter than the through hole 35 a. The screw corresponding to the screw is cut. In the above description, the multi-contact type contacts 37, 41, and 42 such as a multi-ram band are connected to the conductive leaf spring 70 as shown in FIGS.
A number of cuts 71 parallel to the width direction (A-line direction) are provided to form a number of bridge pieces 72 connecting both edges, and these bridge pieces 72 are twisted around the center line in the longitudinal direction as an axis, and the thickness direction is changed. Is a shape obtained by bending a material having the above-mentioned spring property into a ring shape.

When assembling the cable head with the disconnection function configured as described above, first, the insulating bushing 1 is attached to the equipment case (15 in FIG. 5) of the electric equipment, and the outer end of the inner conductor 2 is connected to the equipment side. To the high-voltage conductor. next,
The sleeve 6 of the nut 62 is inserted into the through hole 35a of the wedge fitting 35.
2a, the wedge fitting 35 is connected to the cable conductor 1
1a, the plug 36 is press-fitted from the outside thereof, thereby reducing the diameter of the slit-shaped conical portion 35b of the wedge fitting 35 on the tapered inner surface, and connecting the plug 36 and the cable conductor 11a via the wedge fitting 35. And firmly connect. In this case, by arranging the nut 62 so that the flange 62b is lower than the top surface of the wedge fitting 35, the nut 62 is also connected to the cable conductor 11a via the wedge fitting 35.

The cable conductor 11a to which the plug 36 is attached in this manner is connected to the plug insertion portion 3 of the shield 30.
4 and is connected to the shield 30 by a multi-contact type contact 37. In addition, the power cable 1
The stress cone 14 put on the first insulator 11b is inserted into the tapered opening 1b opened at the lower end of the insulating bushing 1, pressed by the stress cone pressing mechanism 14a and pressed against the tapered surfaces to maintain the dielectric strength. I do. The attachment of the retaining bolt 63 of the dropout prevention mechanism is performed through the right tapered opening 1c and the plug insertion portion 31. That is, the insulating plug 10 is removed from the tapered opening at the right end of the insulating bushing 1, a tool such as an L-shaped wrench is inserted therefrom, a retaining bolt 63 is inserted into the connecting hole 61, and a hexagonal hole 63b formed in the head thereof. Attach a wrench to and rotate,
The lower end of the retaining bolt 63 is screwed into the nut 62.

The connection of the connecting conductor plug 40 and the tightening ring 51 is also performed through the right tapered opening 1c and the plug insertion portion 31. In this case, the insulating plug 10 is removed, and the fastening ring 51 is screwed into the screw portion 32a on the inlet side of the plug insertion portion 32. As a result, the connecting conductor plug 40 is pressed to the left by the pressing portion 51b inserted into the concave portion thereof, and the multi-contact type contacts 41, 4 previously mounted.
2 through the inner conductor 2 or the plug insertion portion 2 of the shielding fitting 30
1 and 32, and are electrically connected. Next, a bolt 52 is inserted into a bolt insertion hole formed in the center of the tightening ring 51 and the connection conductor plug 40, and the vicinity of the left end thereof is screwed into the connection conductor plug 40. Thereafter, the tapered shape of the right end of the insulating bushing 1 is again formed. When the insulating plug 10 is attached to the opening, the connection is completed.

As a result, the cable conductor 11a of the power cable 11 is electrically connected to the high-voltage conductor on the device side via the wedge fitting 35, the plug 36, the shielding fitting 30, the connecting conductor plug 40 and the internal conductor 2. Used for power transmission. On the other hand, when the DC power application test of the power cable 11 is performed, the power cable 11 is disconnected from the device side in order to avoid the DC power application to the device side.
From the insulating bushing 1 and the right tapered opening 1
Insert the tool through c and twist off the fastening ring 51. In this case, since the fastening ring 51 and the connecting conductor plug 40 are connected by the connecting bolt 52, the connecting conductor plug 40 is also pulled out, but since the connecting bolt 52 is loosely fitted to the fastening ring 51, Even if the tightening ring 51 is rotated, no turning force is transmitted to the connecting conductor plug 40,
It is pulled out as it is. After that, the same shape and the same size as the connecting conductor plug 40 (however, the contacts 41 and 42 are not attached, and the grooves for attaching them are not formed).
After inserting the disconnecting insulating plug into the plug insertion hole 1a and attaching the tightening ring 51 and the connecting bolt 52 again, the power application lead cable is attached. This installation is insulated bushing 1
A power supply lead cable is inserted through the tapered opening 1c, and a plug with a multi-contact type contact attached to the end thereof is inserted into the plug insertion portion 31, and attached to the outer periphery near the distal end of the power supply lead cable. This is performed by crimping a pre-molded insulation reinforcement (stress cone) to the tapered opening 1c. In the case where a test voltage cannot be applied even when a test voltage is applied to the device side, such as in an AC power application test, the power supply lead cable can be connected with the connection conductor plug 40 attached. Good.

As described above, in the cable head directly connected to the equipment of the present invention, the adoption of the multi-contact type contact makes the whole compact and adapts to the application of a large current. The weight and cost of the insulating material required for the configuration can be significantly reduced. The insulating bushing 1 has two tapered openings 1.
b, 1c are provided so as to be orthogonal to each other, and the plug insertion portions 31,
34, a power cable can be removably attached thereto. A retaining bolt 63 of a drop-prevention mechanism is inserted into a connection hole 61 provided between the plug insertion portions 31 and 34, and the vicinity of the lower end thereof is used for power supply. Cable side wedge bracket 35
Since the screw is screwed into the nut 62 locked to the plug, the structure of the drop-out prevention mechanism is facilitated, and the attachment and detachment can be easily performed by inserting a tool into the one plug insertion portion 31. In the above description, an example is described in which the present invention is applied to a device direct connection type cable head having a disconnection function. However, the present invention is not limited to this, and the internal conductor 2 and the shielding metal 30 are directly connected. The present invention can be applied to a device-directed cable head having the above structure.

[0018]

According to the present invention, it is possible to obtain a cable head directly connected to a device which is compact and can carry a large current and which is not inadvertently dropped even if a pulling force acts on the cable. it can.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an embodiment of a cable head directly connected to equipment of the present invention.

FIG. 2 is a side view of the embodiment of FIG. 1 with an insulating plug removed.

FIG. 3 is an enlarged longitudinal sectional view showing the vicinity of a shield in the embodiment of FIG. 1;

FIG. 4 is an explanatory view illustrating a multi-contact type contactor used in the present invention (FIG. 4 (b) is a cross-sectional view taken along line bb in FIG. 4 (a)).

FIG. 5 is a longitudinal sectional view illustrating a conventional cable head with a disconnection function.

FIG. 6 is a longitudinal sectional view of a main part explaining a method of using the cable head of FIG. 5;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Insulating bushing 2 ... Internal conductor 3,30 ... Shielding fitting 4 ... Connection conductor plug 5 ... Pre-mold insulator 6,7 ... Shielding electrode 8 ... Spring 9 ... Lid 10 ... Insulation Plug 11 ... Power cable 12 ... Cable terminal 13, 19 ... Contact 14, 18 ... Stress cone 15 ... Case side plate 16 ... Disconnecting insulation plug 17 ... Test lead cable 21,32 ... Plug Insertion portions 31, 34 Plug insertion portions 33, 37, 41, 42 Multi-contact type contact 40 Connection conductor plug 51 Connection ring 52 Connection bolt 61 Connection hole 62 Nut 63 retaining bolt 70 conductive leaf spring 72 bridge piece

Claims (4)

[Claims] 1. An equipment direct connection type cable head in which an inner conductor and a shielding metal are molded in an insulating bushing, wherein the shielding metal has two plug insertion portions which are opened in orthogonal directions. A tapered opening that opens on the axis of the plug insertion portion is formed, and the shield has a top surface of the plug insertion portion that opens downward,
A connection hole is formed between the plug insertion portion and the lower surface of the plug insertion portion that opens laterally, and the plug fixed to the tip of the cable conductor of the power cable is opened downward through a multi-contact type contact. A fastening bolt inserted into the connecting portion and screwed and fixed to a cable conductor side inserted in the plug insertion portion opening downward, wherein the fastening bolt is inserted into the connecting hole. 2. A connecting hole comprising a stepped hole, a large diameter portion of which is opened on a cylindrical lower surface of a plug insertion portion which is opened laterally, and a head of a retaining bolt inserted through the connecting hole is formed by the head. 2. A device-directly connected cable head according to claim 1, wherein said cable head is housed in a large diameter portion, and a lower end of said retaining bolt is screwed to a nut attached to a wedge fitting fixed to said cable conductor. 3. A plug insertion hole is formed between the inner conductor in the insulating bushing and the shielding metal, and a connection conductor plug or a disconnection insulation plug is selectively mounted in the plug insertion hole. The device-directly connected cable head according to claim 1 or 2, wherein: 4. A tightening ring is screwed to a plug insertion portion opening on a surface opposite to the plug insertion portion opening to the side of the shielding metal, and the tightening ring is connected to a conductor plug for connection or an insulating plug for disconnection. 4. The device-directly-connected cable head according to claim 1, wherein the space between the cable heads is connected by a connection bolt loosely fitted to the tightening ring. 5.