JP2000115980A - Plug-in type connection part for power cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plug-in type connection part for power cable, capable of preventing slip-off of a connecting terminal efficiently without causing stability loss in a function as a current-carrying contact even if excessive axial force occurs, by setting the inserting force of a power cable into a socket so as to be smaller than current inserting force and locking a cable plug against the socket after connection. SOLUTION: This plug-in type connection part for power cable is provided with a locking metal fitting 30 arranged at a cable connection end 201, and a locking groove 40 formed at the inner periphery of a recessed part 2 on a housing 3 and so as to be locked with the lock clamp 30. The locking metal fitting 30 is engaged with the locking groove 40 when a plug 204 of the cable connection end 201 and a conductive rod 4 are connected through a garter spring type tulip contact 20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plug-in type connection part for a power cable, and more particularly to an L-type connector for mounting an overhead transmission line and an underground transmission line, which is attached to a tower.
The present invention relates to a plug-in connection portion with a lock mechanism having a structure for preventing accidental withdrawal after connection, which can be suitably embodied in a shaped air terminal box or the like.

[0002]

2. Description of the Related Art In recent years, the number of cases of connecting an overhead transmission line and an underground transmission line on a tower has increased, and for this purpose, an L-shaped connection system which is advantageous for the cable arrangement and the tower configuration on the tower has been adopted. In addition, there has been proposed an L-shaped aerial terminal box having a plug-in type cable connection structure and saving labor on a steel tower.

FIG. 8 shows an example of such an L-shaped aerial terminal box. The L-shaped aerial terminal box is a porcelain tube side unit (female side) 100 pre-assembled and integrated in a factory.
And a cable-side treatment material (male side) 200 that is assembled and processed on site.

A porcelain tube side unit (female side) 100 includes a protective case 101 and a porcelain tube 102, both of which are an adapter 1
03 are integrally connected. An embedded conductor 105 attached to an epoxy bushing 104 is disposed inside the protective case 101, the adapter 103, and the insulator tube 102, and one end (lower end) of a conductor extraction rod 106 is connected to one end (upper end) of the embedded conductor 105. The connection is made by the unit 107. The other end (upper end) of the conductor lead-out bar 106 is connected to the insulator 10
It protrudes above 2. A space formed in the outer periphery of the epoxy bushing 104 and the conductor lead rod 106 in the insulator tube 102 and the adapter 103 is filled with an insulating mixture (insulating oil) 108. Embedded conductor 1
The other end (lower end) of the plug 05 has a plug-in structure provided with a contact (tulip contact) 20 for conductor connection with the male side 200, and the tulip contact 20 is provided in the protective case 101.

On the other hand, a cable side processing material (male side) 20
Reference numeral 0 denotes a prefabricated structure known to those skilled in the art, and a cable (underground transmission line) connection end 201 includes a conductor rod 203 attached to a tip conductor 202, a connection terminal (plug) 204 integrated with the conductor rod 203, Pre-mold stress cone 20
6. It has connection parts such as a cable protection fitting 207 and a compression device 208, and is configured to be fitted to the female side 100.
The cable side processing material (male side) 200 having such a configuration is
It is assembled at the site and inserted into the insulator tube side unit (female side) 100 mounted on a steel tower. The cable plug 204 is connected to the female-side conductor 4 by a plug-in type, a so-called plug-in type, with a female contact (tulip contact) 20.

The plug-in connection 1 of the L-shaped aerial terminal box will be described in more detail with reference to FIG. In this example, the plug-in connection part 1 for a power cable has a substantially cylindrical embedded electrode 10 in the housing 3, one end 11 of which is closed and the other end 12 is open. The embedded electrode 10 forms a socket portion 13 that receives the male side. Also, the closed end 1 of the embedded electrode 10
1, a conductor bar 4 is formed integrally with the socket 13 so as to protrude in the axial direction at the same center.

The protruding end surface of the conductor bar 4 has a flange portion 4b having an outer diameter larger than the outer diameter of the shaft portion 4a of the conductor bar 4.
Are formed integrally, and an annular concave groove 17 is formed on the outer peripheral surface of the conductor rod 4. A garter spring type tulip contact 20 is arranged inside the socket portion 13.

The tulip contact 20 has a plurality of contacts 21 aligned in a circumferential direction to form a ring, and a garter spring 22 is provided on the outer periphery of the ring-shaped contact 21.
Are attached and integrated into a fixed structure.

Further, at both inner ends of each contact 21, convex portions 23, 24 protruding inward in the radial direction are formed, and one convex portion 23 is formed on the outer peripheral surface of the conductor rod 4. The other convex portion 24 fits in the annular groove 17, and the other convex portion 24 fits in the annular groove 205 formed on the outer periphery of the tip plug 204 of the male conductor rod 203 inserted in the socket portion 13.

Therefore, the plug 204 of the power cable connection end 201 inserted into the plug-in connection portion 1 first comes into contact with the projection 24 of each contact 21, and connects the ring-shaped contact 21 to the garter spring 22. It is pushed into the socket portion 13 while expanding radially outward against the spring force. Further, by pushing the plug 204 into the connection portion, the convex portion 24 of the contact 21 fits into the annular concave groove 205 of the plug 204 and prevents the cable plug 204 from coming out of the socket portion 13.

The annular concave groove 205 and the convex portion 24 of the tip plug 204 have a rounded cross section so that the cable can be pulled out if necessary, and a garter spring 22 for fixing the contact 21. Spring force, and
The insertion force of the cable plug 204 into the socket portion 13 and the pull-out force from the socket portion 13 are determined by the fitting dimensions of the contact 21 and the plug 204 and the like. Normally, the insertion force of the cable plug 204 into the socket portion 13 is 80 kgf or less from the viewpoint of workability, and the pull-out force is 190 kF.
gf or more.

In general, in the connecting part assembling work, the cable is not usually pulled out after the cable is inserted and the conductor is connected, but it may be necessary to pull out the cable by exchanging the cable. Therefore, the tulip contact 20 is designed in consideration of such a case so that the tulip contact 20 can be pulled out with a force of about 220 to 350 kgf.

For this reason, after the cable connection end is inserted into the connection portion, depending on the condition of the assembly place and the offset dimension of the cable, an excessive axial force may be generated during the assembling work, or at the time of the bending work or the cleat fixing work after the assembling. Occurs,
When a force higher than the set value is applied to the cable, there is a problem that the conductor connection portion is disengaged. In order to solve such a problem, it is conceivable to set the above-mentioned pulling force 220 to 350 kgf of the tulip contact even higher. However, the insertion force for inserting the cable plug into the socket greatly exceeds 80 kgf. A problem arises in terms of gender.

[0014]

In order to solve the above-mentioned problem, as shown in FIG. 10, engagement surfaces 205a, 2a of the annular concave groove 205 of the tip plug 204 and the convex portion 24 of the contact 21 are formed.
There has been proposed a configuration in which 4a is formed perpendicular to the axis and engaged perpendicular to each other. Therefore, cable connection end 2
Even if a pull-out force is applied to 01, the abutting portions thereof are engaged and locked, so that the cable does not fall off.

In order to release the lock, the pre-mold stress cone 206, the cable protector 207 and the like are moved outward, and then the cylindrical lock release tool 50 is moved.
As shown by the imaginary line in FIG. 10, the end 24a of the contact 21 is pushed outward in the radial direction to disengage the plug 204, whereby the cable connection end 201 can be easily detached. .

However, in the plug-in connection having such a structure, the contact 21 which is a current-carrying part and the plug 20
In order to provide the lock retaining function to 4, when an axial force in the pull-out direction is generated, there is a possibility that a force for expanding the contact 21, that is, a force for making the current-carrying contact unstable may act. Therefore, a further improvement of the plug-in connection for the power cable is required.

Accordingly, an object of the present invention is to set the insertion force of the cable plug into the socket portion to the current insertion force that guarantees good workability, for example, 80 kgf or less, while the plug (cable connection terminal) after connection. The power cable plug that locks the cable to the socket so that even if an excessive axial force is generated, the cable connection end can be effectively prevented from being pulled out without impairing the stability of the function as a current-carrying contact. Is to provide a shaped connection.

Another object of the present invention is that when the cable connection end is pulled out, the lock of the plug and the socket portion can be released very easily using an unlocking tool, and the cable connection end can be pulled out. It is to provide a bayonet connection for a power cable.

[0019]

The above object is achieved by a plug-in connection for a power cable according to the invention. In summary, the present invention provides a housing formed of an insulating material and having a recess for receiving a plug at a cable connection end, a conductor bar disposed in the recess of the housing, and inserted into the housing recess. And a garter spring type tulip contact for electrically connecting the plug at the cable connection end to the conductor rod. A lock fitting placed at the cable connection end,
A locking groove formed in an inner peripheral portion of the housing concave portion and capable of locking with the lock fitting, wherein the plug at the cable connection end and the conductor bar are connected via the garter spring type tulip contact. Wherein the lock fitting engages with the locking groove when connected.

According to one embodiment of the present invention, the lock fitting has a ring-shaped support portion and a locking portion including a plurality of locking claws arranged in a ring shape in a circumferential direction. Each of the locking claws has one end fixed to the ring-shaped support portion and has a shape gradually expanded toward the other end, and protrudes radially outward on its outer peripheral surface. A claw portion that can be locked in the locking groove is formed. here,
The locking claw of the lock fitting is moved by the lock release tool to a position where the claw is released from the locking groove to release the lock.

According to a preferred embodiment of the present invention, the housing is an L-shaped aerial terminal box housing,
A part of the recess of the housing is formed of a substantially cylindrical embedded electrode having one end closed and the other end opened, and the conductor rod is provided at the closed end of the embedded electrode at the same center as the recess. And are integrally formed so as to protrude in the axial direction, and the locking groove is formed on an inner peripheral surface of the embedded electrode.

[0022]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a plug-in connection for a power cable according to the present invention.

FIG. 1 and FIG. 2 show an embodiment of a plug-in type connection portion for a power cable according to the present invention. The plug-in connection part 1 of this embodiment is embodied in an L-shaped aerial terminal box which is an intermediate connection part provided with a branch connection conductor 105 as shown in FIG. 8, but the present invention is not limited to this. However, the present invention can be applied to a linear connection.

In this embodiment, the plug-in connection portion 1 for a power cable is formed of an insulating material such as an epoxy resin, and is a cable-side processing material (male side), that is, a cable connection end 2.
The housing includes an epoxy insulator having a concave portion for receiving a connection terminal (plug) 204, that is, a housing, and a conductor rod disposed in the concave portion of the housing.
In the L-shaped aerial termination box, the housing 3 is formed integrally with the epoxy bushing 104 (FIG. 8).

In this embodiment, the recess 2 of the housing 3 is used.
Are partially provided in the housing 3, one end 1
1 is closed, and is formed of a substantially cylindrical embedded electrode 10 formed of a conductive material and having the other end 12 opened.
The conductor rod 4 is integrally formed at the closed end 11 of the embedded electrode 10 at the same center as the recess 2 in the axial direction.

That is, the embedded electrode 10 is formed of copper or a copper alloy, and has a substantially cylindrical socket portion 13 having one end 11 closed and a concave portion 2 open at the other end 12. Branch connection conductor 10 integrally connected to
5 and are integrally molded in an epoxy insulator inside the housing 3. The epoxy insulator 3 communicates with the opening of the socket portion 13 and extends outward from the socket portion 13 to the right in FIG. An opening 15 is formed.

A flange portion 4b having an outer diameter larger than the outer diameter of the shaft portion 4a of the conductor rod 4 is provided on the projecting end surface of the conductor rod 4.
Are formed integrally, and an annular concave groove 17 is formed on the outer peripheral surface of the conductor rod 4. A garter spring type tulip contact 20 is arranged inside the socket portion 13.

To further illustrate, the tulip contact 20 may include a plurality of contacts 2 as is well known to those skilled in the art.
1 are arranged in the circumferential direction to form a ring, and a garter spring 22 is attached to the outer periphery of the ring-shaped contact 21 and integrally fixed. Also, each contact 2
At both inner end portions of the projection 1, projections 2 projecting inward in the radial direction are provided.
3 and 24 are formed, and one of the protrusions 23 is
And the other convex portion 24 is formed on the outer periphery of the tip plug 204 of the cable connection end 201 inserted into the socket portion 13 as described later. The groove 205 is adapted to fit.

As described above, the power cable connection end 201 has the cylindrical conductor 203 fitted into the end conductor 202 and fixed by crimping or the like. A connection terminal (plug) 204 having a diameter smaller than that of the conductor 203 and having substantially the same diameter as the conductor rod 4 of the socket portion 13 described above is integrally formed at the tip of the cable-side conductor 203. Also, as described above, this plug 2
An annular groove 205 having substantially the same outer diameter as the annular groove 17 formed in the conductor bar 4 of the socket portion 13 is formed in the socket 04, and the contact protrusion 24 of the tulip contact 20 is engaged.

According to the present invention, the lock fitting 30 integrally formed of an elastic metal member, for example, phosphor bronze, is disposed adjacent to the plug 204 at the cable connection end 201. As shown in detail in FIG. 2, the lock fitting 30 has a ring-shaped support portion 31 and a locking portion 33 including a plurality of locking claws 32 arranged in a ring shape in a circumferential direction. . Each locking claw 32 has one end 32a.
Is fixed to the ring-shaped support portion 31, and has a shape gradually expanded toward the other end 32b. That is, each locking claw 3
2 is an inclined surface 34 having a larger diameter than the link-shaped support portion 31.
And a claw portion 36 protruding radially outward at a substantially axial center portion of each locking claw 32 to provide a locking shoulder 35. An inclined surface 37 whose diameter is gradually reduced from the claw portion 36 toward the tip 36b is formed. Each locking claw 32 is considered to be a spring member whose tip portion 32b can be elastically bent in the radial direction around an end portion 32a fixed to the ring-shaped support portion 31. The lock fitting 33 is connected to the cable-side conductor 20.
3 and the inner circumference 2 of the embedded electrode 10.

Further, according to the present embodiment, as shown in FIG.
A gap is provided between the end face 203b of the cable connecting end 201 and the end face 201b of the insulating coating material 201a of the cable connection end 201 to form an annular groove G. The lock fitting 30 is inserted into this annular groove G.
Is disposed. The groove width T of the annular groove G in the axial direction is made larger than the thickness t of the ring-shaped support portion, so that the lock fitting 30 is movable in the annular groove G in the axial direction.

Further, in this embodiment, a locking groove 40 is formed in the inner peripheral surface 2 of the embedded electrode 10. Therefore, as shown in FIG. 1, the locking portion 33 of the lock fitting 30 resiliently moves outward in the radial direction, and the claw portion 36 of each locking claw 32.
Resiliently enters the locking groove 40 so that the locking shoulder 35 can be locked to the peripheral wall of the locking groove 40.

Next, the operation of the plug type connecting portion 1 for a power cable according to the present invention having the above configuration will be described.

When connecting the plug 204 of the cable connection end 201 to the power cable plug-in connection portion 1 of the present invention, as shown in FIG. It is inserted into the opening 15 and pushed in to the left in FIG. As a result, the locking metal fitting 30 is elastically deformed resiliently inward in the radial direction with the locking part tip inclined surface 37 being guided by the socket recess 2, that is, the inner peripheral surface of the embedded electrode 10. Further, the ring support portion 31 is pressed by the end surface 201b of the cable insulator 201a, and moves to the left along with the cable connection end 201.

Further, by pushing the cable connection end 201 into the socket portion 13, the cable connection end 201 is pushed.
Of the plug 204 has a ring-shaped contact 21
Abuts on the convex portion 24. Further, by pushing the plug 204 into the connection portion, the plug 204 expands the contact 21 radially outward against the spring force of the garter spring 22, and Is pushed in towards. When the plug 204 is further pushed into the socket portion 13, the projection 24 of the contact 21 fits into the annular groove 205 of the plug 204 as shown in FIG.

At this time, the locking portion 33 of the lock fitting 30
Is located at the position of the annular groove 40 of the buried electrode 10, so that the locking claws 32 of the locking portion 33 resiliently move outward in the radial direction, and The claw portion 32 resiliently enters the locking groove 40, and the locking shoulder 35 engages with the peripheral wall of the locking groove 40. Next, the pre-mold stress cone 206, the cable protection fitting 207, the compression device 2
A connecting part such as 08 is installed at a predetermined position and fixed.

In order to confirm that the above-described insertion process has been completed, as shown in FIG.
Move to the right with. Thereby, the lock fitting 30
Means that the support portion 31 is connected to the end surface 20 of the cable-side conductor 203.
3b, and is pressed rightward in FIG. However, in this state, since the claw portion 36 of the lock fitting 30 is locked in the locking groove 40, further movement is prevented, and the cable connection end 201 is prevented from being pulled out.

According to the above procedure, the branch conductor 105, the socket portion 13, the conductor bar 4, the contact 21, the plug 204, the conductor 203, and the cable tip conductor 202 are electrically connected and brought into a conductive state.

When the plug 204 is pulled out from the connection part 1, first, as shown in FIG.
The connecting parts such as the pre-molded stress cone 206, the cable protection fitting 207, and the compression device 208 are moved outward and shifted, and then the unlocking tool 50 is moved to the recess 2 through the opening 15 of the epoxy insulator 3. That is, it is inserted into the socket 13.

As shown in FIG. 6, the unlocking tool 50 is constituted by combining split members 50A and 50B, and has a mounting flange 51 formed at one end. Then, the opening 15 of the epoxy insulator 3 is formed. The guide member 52 includes a guide portion 52 that fits into the front end portion, an intermediate portion 53 inclined toward the front end, and a front end portion 54 that is formed in a cylindrical shape.

The tip cylindrical portion 54 of the unlocking tool 50 is
It is inserted into an annular space formed between the inner peripheral surface 2 of the embedded electrode 10 and the outer periphery 31 a of the lock fitting support 31. As a result, the distal end portion of the distal end cylindrical portion 54 comes into contact with the inclined surface 34 of the lock fitting locking claw 32. Further, the tip of the unlocking tool 50 presses the inclined surface 34 inward in the radial direction against the spring force of the locking claw 32,
0 is pushed to the left in FIG. As a result, the claw portion 36 of the lock fitting 30 is moved inward in the circumferential direction, and the engagement of the claw portion 36 with the annular groove 40 is released. This state is shown in FIG.

In this state, the cable connection end 201 is
, The protrusion 24 of the ring-shaped contact 21 first comes into contact with the annular groove 205 of the plug 204, and further pulling out is prevented. So, for example, 190k
gf or more to the cable 201
To the plug 204, the garter spring 22
The contact 21 can be expanded outward in the radial direction against the spring force of (1), and the cable connection end 201 can be pulled outward. This state is shown in FIG.

Actually, when the insertion force and the pull-out force of the power cable plug-in type connection portion 1 having the above-described configuration were measured, the insertion force of the cable plug 204 into the socket portion 13 was found to be not more than the current insertion force of 80 kgf. However, when the cable is moved during or after the assembling work of the connecting portion 1 by cleat fixing work of the cable, the conductor connecting portion, ie,
Even if an excessive axial force is generated in the plug 204, the cable can be prevented from being pulled out. On the other hand, the unlocking tool 5
By using 0 to unlock it,
It could be pulled out with a force of 350 kgf.

[0044]

As described above, the plug-in connection portion for a power cable according to the present invention is formed of an insulating material, and has a housing provided with a recess for receiving a plug at the cable connection end, and a housing having a recess. A power cable plug-in connection comprising a conductor bar arranged and a garter spring tulip contact for electrically connecting the plug of the cable connection end inserted into the housing recess to the conductor bar. A lock fitting disposed at the cable connection end adjacent to the plug at the cable connection end, and a locking groove formed in the inner peripheral portion of the housing recess and capable of locking with the lock fitting, When the plug at the connection end and the conductor bar are connected via the garter spring type tulip contact, the lock fitting is configured to engage with the locking groove. The insertion force of the bull plug into the socket part is the current insertion force that guarantees good workability, for example, 80 kgf or less. On the other hand, after connection, the cable plug is locked to the socket part by the lock fitting, and excessive axial force is generated. Even with this, it is possible to effectively prevent the cable connection end from being pulled out without impairing the stability of the function as the current-carrying contact. (2) When pulling out the cable connection end, the lock between the plug and the socket portion can be released very easily using an unlocking tool, and the cable connection end can be pulled out. The effect can be obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an embodiment of a plug-in type connection portion for a power cable according to the present invention.

FIG. 2 shows an embodiment of a lock fitting, and FIG.
2A is a perspective view, and FIG. 2B is a partial sectional view.

FIG. 3 is a diagram illustrating an operation of inserting a cable connection end into a power cable plug-in connection portion.

FIG. 4 is a diagram illustrating a check operation after insertion of a cable connection end into a power cable plug-in connection portion.

FIG. 5 is a diagram illustrating an operation of pulling out a cable connection end from a power cable plug-in connection portion.

FIG. 6 is a perspective view of a lock release tool.

FIG. 7 is a diagram illustrating an operation of pulling out a cable connection end from a power cable plug-in connection portion.

FIG. 8 is a schematic configuration diagram of one embodiment of an L-shaped aerial terminal box embodying a plug type connection portion for a power cable according to the present invention.

FIG. 9 is a cross-sectional view of an example of a conventional plug-in connection portion for a power cable.

FIG. 10 is a cross-sectional view of another example of a conventional plug-in connection portion for a power cable.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Insertion connection part for electric power cables 2 Concave part 3 Housing (epoxy insulator) 4 Conductor rod 10 Embedded electrode 13 Socket part 14 Branch connection conductor 20 Garter spring type tulip contact 21 Contact 22 Coil spring 23, 24 Contact convex Reference Signs List 25 projection 30 lock fitting 31 support part 32 locking claw 33 locking part 36 claw part 40 socket part groove part 50 unlocking tool 201 cable connection end 204 cable connection terminal (plug)

Claims (4)

[Claims] 1. A housing formed of an insulating material and having a recess for receiving a plug at a cable connection end, a conductor rod disposed in the recess of the housing, and the cable inserted into the housing recess. A garter-spring-type tulip contact for electrically connecting a plug at a connection end to the conductor bar, wherein the cable connection end is adjacent to the plug at the cable connection end. And a locking groove formed in the inner peripheral portion of the housing concave portion and capable of locking with the lock metal, wherein the plug at the cable connection end and the conductor rod are provided. Wherein the lock fitting engages with the locking groove when connected via the garter spring type tulip contact. Connection. 2. The lock fitting includes a ring-shaped support portion and a plurality of locking claws arranged in a ring shape in a circumferential direction. Has one end fixed to the ring-shaped support portion and gradually expanded toward the other end, and has an outer peripheral surface protruding outward in the radial direction and capable of being locked in the locking groove. The plug-in connection part for a power cable according to claim 1, wherein a claw part is formed. 3. The locking claw of the lock fitting is operated by an unlocking tool to move the claw from the locking groove to a position where the lock is released. 2. Plug-in connection for power cable. 4. The housing according to claim 1, wherein the housing is an L-shaped aerial terminal box, and a part of the recess of the housing is formed by a substantially cylindrical embedded electrode having one end closed and the other end opened. The conductor bar is provided at the closed end of the embedded electrode,
4. The power cable according to claim 1, wherein the recess is formed integrally with the concave portion so as to protrude in the axial direction at the same center, and the locking groove is formed on an inner peripheral surface of the buried electrode. 5. Plug-in connection.