JP2000312429A - Cable gland - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cable gland for a multi-cable, whose connecting work is easy and which is capable of preventing the infiltration of water into a terminal part and generation of high stress to the terminal part. SOLUTION: This gland is provided with an adapter 3, formed out of an elastic material having a plurality of through-holes 3a through which the respective single-core cables 2a of a multi-cable 2 penetrate, a retaining body 4 retaining the outer periphery surface 3b of the adapter 3 and including an engagement step part 4b in it, a front ring 5 whose one side is made abut on the adapter 3 and the other side on the engagement step part 4b and which has the same number of penetrating holes 5a as the through-holes 3a, a patch 6 made abut on the adapter 3 and having the same number of penetrating holes 6a as the through-holes 3a, and a lock nut 7 whose female thread part 7a and the male thread part 4c of the retaining body 4 is screwed together. Therefore, the lock nut 7 is tightened to press the patch 6 by a pressing part 7b, thereby compressively deforming the front ring 5 and the adapter 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cable gland used for holding and connecting a terminal portion of a power cable or the like to an electric device, and more particularly to a cable gland for a multi-wire type cable.

[0002]

2. Description of the Related Art A multi-strand cable in which a plurality of single-core cables are twisted (for example, a triplex cable in the case of three-strands) has a smaller current capacity than a multi-core cable having the same copper wire diameter. About 10% larger. The outer diameter is slightly larger, but the weight can be reduced. Excellent flexibility, laying work is easy. There are features such as.

[0003] With respect to such a multi-cable, a conventional terminal holding method will be described with an example of connection of a power cable to an electric device. FIG. 6 shows an example of connection of a motor as an example of electric equipment. A multi-strand cable 2 routed from a power source is first fixed and protected rigidly by a conduit 12. A flexible tube 13 is disposed between the electric conduit 12 and the motor 10, and the multi-strand cable 2 is routed and routed therein. One end of the flexible tube 13 is connected to the conduit tube 12 via the combination connector 14, and the other end is connected to the terminal box 11 of the motor 10 via the straight box connector 15. In this way, the terminal section of the multi-strand cable 2 is isolated and protected from the external environment. Here, there is no particular constraint between the multi-strand cable 2 and the flexible tube 13 or between the multi-strand cable 2 and the straight box connector 15.

[0004]

However, in the conventional cable holding method as described above, the flexible tube requires a separate component such as a straight box connector in order to secure the sealing performance of the multi-cable terminal holding portion. Also, the work of passing the multi-strand cable through the flexible tube is sometimes complicated. Furthermore, since there is no means for restraining the multi-strand cable itself, there has been a problem that excessive stress may be generated in the terminal connection portion due to vibration of the connection device or the like.

On the other hand, for a multi-core cable having a circular cross section, a cable gland 5 as shown in FIG.
1 is generally available. The cable gland 51 is composed of an adapter 53 made of a rubber material or the like, a holding body 54, and a lock nut 57. In use, the adapter 53 is compressed and deformed by tightening the lock nut 57, so that the periphery of the cable 52, The sealing performance around the adapter 53 is obtained, and the cable 52 is also restrained. However, such a cable gland 5
Reference numeral 1 denotes a structure that cannot cope with holding a multi-cable.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and can prevent water from penetrating into the terminal portion of a multi-strand cable without using a flexible tube or a straight box connector. An object of the present invention is to provide a multi-cable cable gland which is easy and can prevent the occurrence of high stress in a terminal portion by fixing the multi-strand cable itself to a connection device.

[0007]

According to a first aspect of the present invention, there is provided a cable gland for holding a multi-strand cable in which two or more single-core cables are twisted. An adapter made of an elastic material having a plurality of through holes through which each single-core cable of the strip cable is inserted, and a holder having an adapter fitting portion for fitting the adapter,
Holding means for compressing and holding the adapter in the axial direction of the through-hole while the single-core cables are inserted.

[0008] According to this configuration, by securely connecting and holding the end portion of the multi-cable to the electric device or the like, the stress of the terminal portion generated by the vibration of the electric device can be reduced. It is possible to prevent water from entering the terminal portion without using the terminal.

According to a second aspect of the present invention, in the cable gland according to the first aspect, the holding means comes into contact with an engagement step formed on an inner surface of the holding body and one surface of the adapter, The through-hole has an insertion hole whose number and arrangement coincide with each other, and includes a front ring locked by the engagement step portion, and a pressing member that presses the other surface of the adapter. And

[0010] According to this configuration, the central portion of the adapter, that is, the region surrounded by the plurality of through-holes abuts on the front ring and is compressed, so that the sealing performance around the cable and the cable binding force are improved.

According to a third aspect of the present invention, in the cable gland according to the second aspect, the pressing member has a through plate having an insertion hole whose number and arrangement coincide with the number of the through holes, and a corresponding plate is connected to the adapter. And a lock nut having a female screw portion on one end side, and a male screw portion screwed to the female screw portion is formed on the outer peripheral surface of the holding body. It is characterized by the following.

According to this structure, the adapter of the elastic material is compressed by rotating and screwing the lock nut,
The diameter of the through hole provided in the adapter is reduced, so that the adapter and each single-core cable are in close contact with each other, and the cable is held.

According to a fourth aspect of the present invention, in the cable gland according to any one of the first to third aspects, the outer peripheral surface of the adapter and the adapter fitting portion of the holder have a truncated cone peripheral surface shape. It is characterized by.

According to this configuration, the adapter is compressed in the axial direction of the through hole and contracts in its outer diameter at the same time due to the peripheral surface shape of the truncated cone, so that the adapter is in a more compressed and deformed state than when held on the inner surface of the cylinder. Is improved, thereby improving the sealing performance around the cable and the cable binding force.

The invention according to claim 5 is the invention according to claim 3 or 4.
In the above described cable gland, the backing plate has a protruding portion protruding from a peripheral edge portion on a side of the adapter at a center portion thereof.

According to this structure, the center part of the adapter can be strongly compressed, so that the sealing performance around the cable and the cable binding force are improved as compared with the case where the adapter is compressed in a plane.

According to a sixth aspect of the present invention, in the cable gland according to the fifth aspect, the adapter has a concave portion on the side of the backing plate on which the projecting portion is seated.

According to this structure, the adapter and the backing plate are centered, and the compression deformation state of the adapter can be improved, thereby further improving the sealing performance around the cable and the cable restraining force. .

[0019]

Embodiments of the present invention will be described below in detail with reference to the drawings. Here, as the multi-strand cable, a description will be given by exemplifying a three-triple type cable which is a typical power cable, but the multi-strand cable to which the cable gland according to the present invention is applied is as follows.
Needless to say, it is not limited to Article 3.

FIG. 1 is a partial sectional view of a cable gland according to an embodiment of the present invention in a temporarily assembled state, and FIG.
FIG. 2 is a sectional view taken along line AA in FIG. 1. The cable gland 1 is for holding the multi-strand cable 2. The multi-strand cable 2 shown in the present embodiment is called a triplex type, and three similar single-core cables 2a
As one set. Accordingly, when the cable is inserted into the cable gland 1, as shown in the cross section in FIG.

At a substantially central portion of the cable gland 1, an adapter 3 made of a relatively soft elastic material such as a rubber material is arranged. This adapter 3 is formed in the shape of a truncated cone, and its outer surface is composed of an outer peripheral surface 3b, a front surface 3c, and a rear surface 3d. Then, from the rear surface 3d to the front surface 3
c, there are three through holes 3a through which each single core cable 2a is inserted, and these through holes 3a
As shown in the cross section in FIG. 2, the vertexes are arranged at the positions of the vertices of an equilateral triangle. The inner diameter of the through hole 3a is formed slightly larger than the outer diameter of each single-core cable 2a. On the other hand, a conical recess 3e is formed at the center of the rear surface 3d.

Outside the outer peripheral surface 3b of the adapter 3, an adapter fitting portion 4a of the holder 4 is arranged. This adapter fitting portion 4a is similar to the outer peripheral surface 3b of the adapter 3,
It has a conical peripheral shape. The holding body 4 has a male thread 4c at one end of the outer peripheral surface and a male thread 4d at the other end, and a flange 4e projecting outward is formed between the male threads 4c. ing. Further, the holding body 4 has an axis O near the inner end of the adapter fitting portion 4a on the inner surface thereof.
Is provided with an engagement step portion 4b which is an annular plane perpendicular to the projection.

The front surface 3c of the adapter 3 is in contact with the disk-shaped front ring 5, and the opposite surface of the front ring 5 is in contact with the engaging step 4b of the holder 4. The front ring 5 has a plurality of (here, three) insertion holes 5a corresponding to the number of through holes 3a in the adapter 3. The inside diameter of these insertion holes 5a is set to be larger than the outside diameter of the single-core cable 2a.

On the other hand, the backing plate 6 is in contact with the rear surface 3d of the adapter 3. The backing plate 6 has a plurality of (three in this case) insertion holes 6 a corresponding to the number of through holes 3 a in the adapter 3, like the front ring 5. The inside diameter of these insertion holes 6a is set to be larger than the outside diameter of the single-core cable 2a. Further, the backing plate 6 has a protruding portion 6b protruding from the peripheral edge on the side of the adapter 3 at the center thereof.
The projecting portion 6b in the present embodiment is formed by making one surface of the backing plate 6 into a conical shape.

Further, a lock nut 7 is arranged as a pressing member of the adapter 3 so as to surround the periphery of the backing plate 6. The lock nut 7 has a female screw portion 7a which is screwed into the male screw portion 4c of the holder 4 on the inner peripheral surface on one end side, and the female screw portion 7a is It has a pressing portion 7b that presses the backing plate 6 by being screwed into 4a.

Next, a method of assembling and using the cable gland 1 having the above configuration will be described. FIG.
1 shows a state in which the lock nut 7 is screwed and advanced to the holding body 4 from the temporarily assembled state shown in FIG. 1 to hold each single-core cable 2a.

First, the three single-core cables 2a of the multi-strand cable 2 are inserted through the lock nut 7, the backing plate 6, the adapter 3, the front ring 5, and the holder 4 in this order. The female thread 7a of the lock nut 7 is engaged with the male thread 4c of the holder 4. This results in the temporary assembly state shown in FIG.

Next, the lock nut 7 is removed from the temporarily assembled state.
Tighten. Then, the contact plate 6 becomes the lock nut 7
1 and moves rightward in FIG. 1 along the axis O. The protruding portion 6b comes into contact with the concave portion 3e of the adapter 3 to perform centering. And adapter 3
Also moves rightward and abuts on the front ring 5, and the front ring 5 abuts the engaging step 4 b of the holder 4. From this point, when the lock nut 7 is further continued to be tightened, the front ring 5 is firmly supported by the engagement step portion 4b, so that the compression deformation of the adapter 3, which is an elastic body, proceeds.
Since the outer peripheral surface 3b of the adapter 3 is supported in close contact with the adapter fitting portion 4a of the holder 4, the rubber material that has lost its place acts to close the gap between the through hole 3a and the single-core cable 2a.

On the other hand, the rubber material in the region surrounded by the three through holes 3a also undergoes an expansion deformation outward from the axis O due to the compression in the direction of the axis O. This means that the single core cable 2a and the through hole It acts to compress and fill the gap with 3a from the direction of the axis O. Note that, as in the present embodiment, when one surface of the backing plate 6 has a conical shape, the central portion of the adapter 3 is more strongly compressed than in the case where it is a flat surface. The effect becomes more pronounced.

FIG. 3 shows a state in which the tightening of the lock nut 7 has been completed. Since the single-core cable 2a is in close contact with the adapter 3 over the entire circumference thereof and further receives a compressive force, not only a sealing action occurs at this portion, but also the movement of the single-core cable 2a in the direction of the axis O is restricted. Will be. Thus, the holding property and the sealing property of the multi-strand cable 2 by the cable gland 1 are realized.

FIG. 3 further shows a connection state between the cable gland 1 and the terminal box 11 assembled as described above. The assembly is performed by the male screw 4
d is passed through a hole 11 a provided in the terminal box 11 and tightened with a nut 20. At this time, a sealing member 21 is provided between the flange 4 e of the holder 4 and the terminal box 11.
In this case, the sealing performance of this portion can be ensured, and the multi-cable terminal section can be protected from the external environment, similarly to the conventional connection method shown in FIG.

The assembling of this part may be performed in the order in which the holder 4 is fixed to the terminal box 11 first, and the front ring 5 and the adapter 3 are assembled later.

FIG. 5 shows a cable gland 1 according to the present invention.
5 shows a state in which the multi-strand cable 2 is connected to the motor 10, and it can be seen that the flexible tube 13 and the straight box connector 15 are not required as compared with the conventional connection state shown in FIG. An insulating bushing 17 is used at the outlet of the conduit tube 12 instead of the combination connector 14.

FIG. 4 shows another embodiment of the backing plate together with the lock nut 7. The backing plate 16 in the present embodiment has an insertion hole 16a similarly to the backing plate 6.
And a projection 16b, and an annular projection 16c is formed on the back side thereof. The outer diameter of the projection 16c is slightly smaller than the inner diameter of the hole 7c of the lock nut 7, so that the centering of the backing plate 16 can be performed reliably. In this case, the recess 3e formed in the adapter 3 may be eliminated.

In the embodiments described above, the protruding portion 6b or 16b is provided on the backing plate 6 or 16,
The surface of the front ring 5 on the adapter 3 side has been flat,
If a protrusion is added to the front ring 5 as well, the compression of the center portion of the adapter 3 in the direction of the axis O can be further increased.

Further, in the above description, the pressing member for pressing the adapter is a lock nut having a female screw portion. However, the pressing member is not provided with a screw portion, and the adapter is compressed by some means. The configuration may be such that the pressing member is locked to the holding member using the elastic repulsion force.

[0037]

As described above, when the cable gland according to the present invention is used, a multi-strand cable can be easily connected and fixed to an electric device without using a flexible tube or a straight box connector. It is possible to obtain an excellent effect that it is possible to prevent water from entering the terminal portion and to prevent the occurrence of high stress in the multi-cable terminal portion.

[Brief description of the drawings]

FIG. 1 is a partial sectional view showing a temporarily assembled state of an embodiment of a cable gland according to the present invention.

FIG. 2 is a sectional view taken along line AA in FIG.

FIG. 3 is a partial cross-sectional view showing a state in which a lock nut is tightened from the temporarily assembled state in FIG. 1 to hold a multi-strand cable.

FIG. 4 is a partial cross-sectional view showing another embodiment relating to a backing plate.

FIG. 5 is a perspective view showing a state where a multi-strand cable is connected to a motor using the cable gland according to the present invention.

FIG. 6 is a perspective view showing a state in which a multi-strand cable is connected to a motor by a conventional method.

FIG. 7 is a sectional view showing a conventional cable gland for a multi-core cable.

[Description of Signs] 1 Cable gland 2 Multi-strand cable 2a Single-core cable 3 Adapter 3a Through-hole 3b Outer peripheral surface 3e Depression 4 Holder 4a Adapter / fitting portion 4b Engagement step 4c / 4d Male thread 5 Front ring 6 Backing plate 6b Projecting part 5a ・ 6a Insertion hole 7 Lock nut 7a Female screw part 7b Pressing part 10 Motor 11 Terminal box

Claims (6)

[Claims] 1. A cable gland for holding a multi-strand cable in which two or more single-strand cables are twisted, comprising: an elastic material having a plurality of through holes through which each single-strand cable of the multi-strand cable is inserted. An adapter, a holder having an adapter fitting portion for fitting the adapter, and holding means for compressing and holding the adapter in the axial direction of the through hole with the single-core cables being inserted. A cable gland characterized by that. 2. The holding means has an engaging step formed on an inner surface of the holding body, and an insertion hole which is in contact with one surface of the adapter and whose number and arrangement coincide with the number of the through holes. And
The cable gland according to claim 1, further comprising a front ring locked by the engagement step, and a pressing member that presses the other surface of the adapter. 3. The pressing member has a backing plate having an insertion hole whose number and arrangement coincide with the through hole, a pressing portion for pressing the corresponding plate toward the adapter, and one end side. The cable gland according to claim 2, further comprising a lock nut having a female screw portion, and a male screw portion screwed to the female screw portion is formed on an outer peripheral surface of the holding body. 4. The cable gland according to claim 1, wherein the outer peripheral surface of the adapter and the adapter fitting portion of the holder have a truncated cone peripheral surface shape. 5. The cable gland according to claim 3, wherein the backing plate has a protruding portion protruding from a peripheral portion on a side of the adapter at a center portion thereof. 6. The cable gland according to claim 5, wherein the adapter has a concave portion on the side of the backing plate on which the protruding portion is seated.