JP2022150694A - Attachment member attached to tip of power cable and working method for making use of the same to tow power cable - Google Patents

Abstract

To provide an attachment member and a working method capable of simplifying a step of attaching an attachment part to a power cable and thereby improving the efficiency of the power cable towing operation.SOLUTION: The attachment member is attached to a tip part of the power cable when the power cable is towed. The attachment member includes an attachment part having an insertion hole into which the tip part is inserted, provided with a towing part at one end in an extension direction of the insertion hole, and open on the other end in the extension direction of the insertion hole so that the tip can be inserted into the insertion hole. The inner surface of the attachment part surrounding the interior space of the insertion hole has an outwardly recessed recess that constitutes an adhesive coating part to which an adhesive for bonding the tip is bonded so that the adhesive coated on the adhesive coating part accumulates.SELECTED DRAWING: Figure 2

Description

TECHNICAL FIELD The present invention relates to an attachment member attached to the tip of a power cable, and a working method for pulling the power cable using the attachment member.

2. Description of the Related Art Conventionally, there is known a jig (mounting member) called a pulling eye that is mounted on the terminal portion of a power cable when laying the power cable or removing the existing power cable. By pulling the pulling eye attached to the power cable with a traction device, the power cable can be pulled into a conduit, etc., and can be easily moved to the connection location where the target device to which the power cable is connected is installed. Become.

Generally, it is known that the pulling eye is compression connected to the exposed cable conductor at the end of the power cable. Further, in Patent Document 1, an adhesive is applied between the tip of the optical cable and the inner surface of the insertion hole in the pooling eye, and a waterproof compound is applied to the tip of the optical cable to form the pooling eye. A method for connecting with an optical cable is disclosed.

JP-A-2000-2827

By the way, when moving a power cable by pulling it with a pulling eye, it takes a long time to lay a long line and perform a plurality of pulling operations. Specifically, a step of stripping off the covering portion of the power cable to expose the cable conductor, a step of attaching a pulling eye, and a step of cutting the cable after pulling are repeatedly performed.

Among these processes, the process of attaching the pulling eye, that is, the process of compressing and connecting the attachment part (attachment part) of the pulling eye to the cable conductor, takes the most time. There has been a demand for simplification of the process of attaching the pulling eye to the power cable.

An object of the present invention is to simplify the process of attaching the attachment portion to the power cable, and thereby to improve the efficiency of pulling work of the power cable. An object of the present invention is to provide a work method for pulling a power cable using the mounting member.

The attachment member attached to the tip of the power cable according to the present invention is
A mounting member that is attached to the tip of the power cable when towing the power cable,
An insertion hole into which the tip is inserted is provided, a traction part is provided on one end in the extension direction of the insertion hole, and the tip can be inserted into the insertion hole on the other end in the extension direction of the insertion hole. having a mounting part that opens to
The inner surface of the mounting portion surrounding the inner space of the insertion hole is
configuring an adhesive application section to which an adhesive for bonding the tip is applied;
It has a concave portion recessed outward so that the adhesive applied to the adhesive application portion is accumulated.

A working method for pulling the power cable using the mounting member according to the present invention includes:
It has an insertion hole into which the tip of the power cable is inserted, a traction part is provided on one end in the extension direction of the insertion hole, and the tip is inserted into the insertion hole on the other end in the extension direction of the insertion hole. The mounting portion has an insertable opening, and the inner surface of the mounting portion surrounding the inner space of the insertion hole constitutes an adhesive application portion to which an adhesive for bonding the tip portion is applied. A work method for pulling the power cable using a mounting member having a concave portion recessed outward so that the adhesive applied to the adhesive applied portion is accumulated,
an inserting step of inserting the tip portion into the insertion hole; and an applying step of applying the adhesive to at least one of the tip portion and the inner surface before or after the inserting step; A bonding step of bonding to the mounting part;
a pulling step of pulling the power cable with the pulling portion through the mounting portion after the bonding step;
have

ADVANTAGE OF THE INVENTION According to this invention, the simplification of the process which attaches|wears a power cable with an attachment part can be aimed at, and the efficiency of pulling work of an electric power cable can be aimed at by extension.

FIG. 4 is a half cross-sectional view showing a pulling eye having a mounting portion according to an embodiment of the present invention; FIG. 4 is a half cross-sectional view showing the pulling eye in a state in which the insertion hole of the mounting portion is filled with adhesive; FIG. 10 is a half cross-sectional view showing a pulling eye with recessed cable conductors inserted; FIG. 11 is a half cross-sectional view showing a modified pulling eye with spacers; FIG. 11 is a half cross-sectional view showing a modified pulling eye having a wedge member;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a half-sectional view showing a pulling eye 1 having a mounting portion according to an embodiment of the invention.

As shown in FIG. 1 , the pulling eye 1 is a mounting member for pulling the power cable 2 and has a connecting portion 10 and a mounting portion 20 . The connecting part 10 is a pulling part connected to a pulling device (not shown) such as an eye nut for pulling the power cable 2 to the connection place, and is connected to the mounting part 20 .

The attachment portion 20 is a portion attached to the power cable 2 . The mounting portion 20 extends in a predetermined direction and has a cylindrical shape with a bottom. Incidentally, the predetermined direction is the direction in which the power cable 2 is pulled. The mounting portion 20 has an insertion hole 21 . The insertion hole 21 opens at the end opposite to the connecting portion with the connecting portion 10 (the other end in the extending direction of the insertion hole 21). The insertion hole 21 extends in a predetermined direction to the bottom portion located on the side of the connecting portion with the connecting portion 10 (one end in the extending direction of the insertion hole 21), and the cable conductor 3 (tip portion) of the power cable 2 is inserted.

The diameter of the insertion hole 21 is larger than the diameter of the cable conductor 3, and when the cable conductor 3 is inserted into the insertion hole 21, the inner surface 21A, which is the inner peripheral surface of the mounting portion 20, surrounds the inner space of the insertion hole 21. and the cable conductor 3, there is a slight gap. The gap between the inner surface 21A and the cable conductor 3 is a very small gap that other members cannot enter. In addition, in FIG. 1 and the like, the gap between the inner surface 21A and the cable conductor 3 is enlarged in consideration of the visibility of the drawing.

An adhesive for adhering the cable conductor 3 is applied to the inner surface 21A of the mounting portion 20 . In other words, the inner surface 21A of the mounting portion 20 constitutes an adhesive application portion to which an adhesive for bonding the tip portion of the power cable 2 is applied.

The length of the gap between the inner surface 21A of the mounting portion 20 and the cable conductor 3 can be appropriately set according to the type of adhesive.

An inner surface 21A of the mounting portion 20 has a concave portion 21B that is concave to the side opposite to the inner space of the insertion hole 21, that is, to the outside. Specifically, a plurality of recesses 21B are provided in the extending direction of the insertion hole 21, and are provided over the entire inner surface 21A in the circumferential direction. In other words, the inner surface 21A of the insertion hole 21 has, for example, a threaded shape. In addition, the recessed part 21B is not limited to this, For example, the recessed part 21B may be formed by a rough cutting bit.

By providing the concave portion 21B in this way, as shown in FIG. 2, the adhesive G applied to the inner surface 21A (adhesive applied portion) of the insertion hole 21 is accumulated in the concave portion 21B.

As a result, the anchoring effect based on the shearing force of the adhesive G accumulated in the recess 21B can stabilize the pulling force of the power cable 2 while increasing the bonding strength between the mounting portion 20 and the power cable 2.

Specifically, when the cable conductor 3 and the mounting portion 20 are adhered with the adhesive G and the pulling eye 1 is pulled, the cable conductor 3 generates a reaction force T(N) as tension. This resistance T depends on the shear strength P (N/mm ² ) of the adhesive G.

In addition to the repulsive force T of the adhesive G spreading planarly between the surface of the cable conductor 3 and the inner surface 21A, the adhesive G enters and accumulates in the recess 21B so as to have a thickness in the radial direction that intersects the pulling direction. The total tension added with the shear stress t1 of the adhesive G acts when the pulling eye 1 is pulled. As a result, it is possible to stabilize the pulling force of the power cable 2 in the pulling direction while increasing the bonding strength between the mounting portion 20 and the power cable 2 .

In addition, the relationship between the reaction force T and the shear force P is expressed by the following formula (1).
L>T/(d×π×P) (1)

L in equation (1) is the length (mm) of the cable conductor 3 . d in the formula (1) is the diameter length (mm) of the cable conductor 3 .

Examples of the adhesive G include a cyanoacrylate adhesive, a reactive resin adhesive (reactive acrylic), an alkyl cyanoacrylate adhesive, a one-liquid thermosetting epoxy adhesive, and a methacrylate anaerobic adhesive. agents, α-cyanoacrylate jelly-like instant adhesives, and the like. Also, the adhesive G may be, for example, jelly-like, liquid, etc., as long as it can accumulate in the recess 21B and bond the mounting portion 20 and the cable conductor 3 together. But it's okay.

Further, the mounting portion 20 is provided with a through hole 21</b>C penetrating from the outer surface positioned around the inner surface of the mounting portion 20 toward the insertion hole 21 . In other words, the through hole 21</b>C is arranged at a position facing the side surface of the cable conductor 3 when the cable conductor 3 is inserted into the insertion hole 21 in the mounting portion 20 . 21 C of through-holes are provided in four on the upper side of the mounting part 20 in FIG.1 and FIG.2.

By providing the through hole 21C in this manner, after the cable conductor 3 is installed in the insertion hole 21, the adhesive G can be injected between the installation portion 20 and the cable conductor 3 through the through hole 21C. It becomes possible.

Further, by providing the through hole 21C, when the space between the mounting portion 20 and the cable conductor 3 is filled with the adhesive G, the adhesive G overflows from the through hole 21C. It is also possible to confirm that the gap has been filled with the adhesive G.

Further, by providing the through hole 21C, it is possible to mechanically fix the mounting portion 20 and the cable conductor 3 by providing a fixing member 30 such as a set screw through the through hole 21C. The fixing member 30 has, for example, a tip that can be bitten into the cable conductor 3 . A hole into which the tip of the fixing member 30 is inserted may be formed in the cable conductor 3 .

Thus, by providing the fixing member 30, the mechanical gripping force t2 of the fixing member 30 can be added to the above total tension (T and t1) to further increase the total tension. As a result, the bonding strength between the mounting portion 20 and the cable conductor 3 can be further increased.

Also, the size of the through-hole 21C into which the fixing member 30 is inserted may be made different from the sizes of the other through-holes 21C according to the size of the fixing member 30 .

Also, a plurality of fixing members 30 may be provided. By providing a plurality of fixing members 30, the mechanical holding force of the fixing members 30 can be increased, so that the bonding strength between the mounting portion 20 and the cable conductor 3 can be further increased.

Next, an example of a series of work processes from attaching the pulling eye 1 to the power cable 2 to moving it will be described.

First, the operator applies the adhesive G to both the cable conductor 3 of the power cable 2 and the insertion hole 21 of the mounting portion 20 . The adhesive G may be applied by the operator to either the cable conductor 3 of the power cable 2 or the insertion hole 21 of the mounting portion 20 .

Next, the operator inserts the cable conductor 3 into the insertion hole 21 of the mounting portion 20 . After inserting the cable conductor 3 into the insertion hole 21 of the mounting portion 20, the operator may inject the adhesive G between the mounting portion 20 and the cable conductor 3 through the through hole 21C.

As a result, the adhesive G can be easily filled between the cable conductor 3 and the mounting portion 20 . In addition, the operator can confirm that the adhesive G is overflowing from the through hole 21C, and by extension, it is possible to easily confirm that the adhesive G is filled between the cable conductor 3 and the mounting portion 20. can.

After inserting the cable conductor 3 into the insertion hole 21 of the mounting section 20 , the operator may mechanically fix the mounting section 20 and the cable conductor 3 with the fixing member 30 .

Thereby, the bonding strength between the mounting portion 20 and the power cable 2 can be further increased.

After inserting the cable conductor 3 into the insertion hole 21, the worker leaves the pulling eye 1 and the power cable 2 to cure the adhesive G to bond the mounting portion 20 and the power cable 2 together. The connecting part 10 of the pooling eye 1 is pulled by a pulling device or the like to pull the power cable 2 through the mounting part 20 . In this manner, the power cable 2 is moved to lay or remove the power cable 2 .

By the way, when using a pulling eye for compression connection to the power cable, first, it is necessary to carry a press device for compression connection to the work place, but the weight of the press device increases according to the size of the power cable 2.

For this reason, it is necessary to secure a plurality of workers for the compression connection and to adjust the work dates and times of the plurality of workers.

On the other hand, in the present embodiment, the pulling eye 1 and the power cable 2 are connected with the adhesive G, so that the pulling eye 1 and the power cable 2 can be adhered with a simple operation. That is, in the present embodiment, the process of attaching the pulling eye 1 to the power cable 2 can be simplified, and the pulling work of the power cable 2 can be made more efficient.

In addition, since the recess 21B is provided on the inner surface of the insertion hole 21 of the mounting portion 20, the adhesive G can be hardened while remaining in the recess 21B. As a result, the anchoring effect of the adhesive G can increase the adhesive strength between the mounting portion 20 and the power cable 2 and stabilize the pulling force of the power cable 2 .

Further, when the cable conductor 3 is composed of a stranded wire obtained by twisting a plurality of strands, dents are also formed between the strands. accumulates. As a result, the anchor effect of the adhesive G accumulated in the recess 21B and the recess on the cable conductor 3 side can be further enhanced, and the pulling force of the power cable 2 can be further stabilized.

Moreover, the anchoring effect of the adhesive G can be further enhanced by entering the adhesive G into the through holes 21C, and the pulling force of the power cable 2 can be further stabilized.

Further, as shown in FIG. 3, an operator processes and forms depressions 3A on the surface of the cable conductor 3 to form an uneven shape, and the adhesive G is accumulated in the depressions 3A so that the adhesive G can be applied. The anchor effect may be enhanced. Further, by providing the recess 3A at a position corresponding to the recess 21B, it is possible to easily enhance the anchor effect. The step of processing and forming an uneven shape on the surface of the cable conductor 3 is performed before the step of bonding the cable conductor 3 to the mounting portion, such as before inserting the cable conductor 3 into the insertion hole 21 . Further, the uneven shape may be formed by roughening the surface of the cable conductor 3 with a file or the like.

In the above-described embodiment, the gap between the inner surface 21A and the cable conductor 3 was a very small gap. , a spacer 40 may be provided, and a receiving portion 21D for receiving the end face portion of the cable conductor 3 in the insertion hole 21 may be provided.

The spacer 40 is an elastic member such as rubber or packing, and has a first portion 41 and a second portion 42, for example. The first part 41 and the second part 42 are cylindrical and configured to be arranged around the cable conductor 3 .

More specifically, the first portion 41 is a portion arranged in a gap between the mounting portion 20 and the cable conductor 3, and is configured to extend in the direction along the side surface of the cable conductor 3 (extending direction of the mounting portion 20). It is The second portion 42 is a portion of the first portion 41 that is connected to an end portion corresponding to the edge portion of the insertion hole 21 of the mounting portion 20 and arranged in close contact with the edge portion. It is configured to protrude in the radial direction of the cable conductor 3.

That is, the spacer 40 has an L-shaped cross section composed of the first portion 41 and the second portion 42 . By disposing the first portion 41 of the spacer 40 in the gap between the mounting portion 20 and the cable conductor 3, the gap can be easily maintained at a constant width.

Further, the receiving portion 21D is positioned at a position corresponding to the end face portion of the cable conductor 3 of the insertion hole 21, and has a shape that allows the end face to be fitted. By providing the receiving portion 21D, the end surface portion of the cable conductor 3 is positioned within the insertion hole 21, and the gap between the mounting portion 20 and the cable conductor 3 can be easily maintained at a constant width.

Moreover, the space between the mounting portion 20 and the cable conductor 3 is kept constant by the spacer 40 and the receiving portion 21D, so that the adhesive can be sufficiently and uniformly filled. As a result, while the above-mentioned anchor effect is exhibited, the pulling eye 1 is not eccentric in the pulling direction, so that no bending moment is applied, the pulling force of the power cable 2 can be further stabilized, and repetitive usability can be improved. can be improved.

Moreover, as shown in FIG. 5, the structure which provided the wedge member 50 may be sufficient. In the mounting portion 20 of the pooling eye 1 according to this embodiment, the bottom surface of the insertion hole 21 (the end surface of the mounting portion 20 on the one end side in the extending direction) is provided from the outer surface of the mounting portion 20 to the bottom surface of the insertion hole 21. is provided with a through hole 21E penetrating in the extension direction of the mounting portion 20 (horizontal direction shown in FIG. 5). In other words, the through hole 21</b>E is arranged at a position in the mounting portion 20 facing the end surface of the cable conductor 3 when the cable conductor 3 is inserted into the insertion hole 21 .

The wedge member 50 is provided by being driven into the end face of the cable conductor 3 through the through hole 21E. By doing so, the end surface side portion of the cable conductor 3 is spread outward (for example, radially) by the wedge member 50, and spreads in a plane in the gap between the outer periphery of the end surface portion of the cable conductor 3 and the inner surface 21A. Since it is pressed against the adhesive G, the adhesive force between the end surface portion of the cable conductor 3 and the mounting portion 20 can be complemented. Moreover, since the end surface of the cable conductor 3 can be fixed to the bottom portion of the insertion hole 21 by the wedge member 50, the adhesive force between the cable conductor 3 and the mounting portion 20 can be enhanced. The traction device may be connected to the connection portion 10 with the wedge member 50 driven in, or may be connected to the connection portion 10 after the driven wedge member 50 is removed after the cable conductor 3 is adhered. . In the former case, by pressing the wedge member 50 in the driving direction with the connected pulling device, the adhesive force between the end surface portion of the cable conductor 3 and the mounting portion 20 can be further complemented.

In addition, in the above-described embodiment, the recess 21B has a threaded shape, but the present invention is not limited to this. It may be of any shape. Further, from the viewpoint of improving the anchoring effect, the recess may be provided at a position corresponding to the pitch of the strands of the cable conductor 3 .

Further, in the above-described embodiment, the mounting portion 20 is configured in a cylindrical shape, but the present invention is not limited to this, as long as the adhesive can be filled between the insertion hole and the cable conductor. Such a configuration may be used.

Further, in the above-described embodiment, the connecting portion 10 and the mounting portion 20 are separate members, but the present invention is not limited to this, and the connecting portion and the mounting portion may be integrally configured.

Further, in the above embodiment, the pulling eye 1 is used as the mounting member, but the mounting portion may be used as the mounting member.

Further, although the through hole 21C is provided in the above embodiment, the present invention is not limited to this, and the through hole may not be provided.

In addition, each of the above-described embodiments is merely an example of specific implementation of the present invention, and the technical scope of the present invention should not be construed to be limited by these. Thus, the invention may be embodied in various forms without departing from its spirit or essential characteristics.

Reference Signs List 1 pooling eye 2 power cable 3 cable conductor 10 connecting portion 20 mounting portion 21 insertion hole 21A inner surface 21B recess 21C through hole 21D receiving portion 30 fixing member 40 spacer 41 first part 42 second part 50 wedge member

Claims (11)

A mounting member that is attached to the tip of the power cable when towing the power cable,
An insertion hole into which the tip is inserted is provided, a traction part is provided on one end in the extension direction of the insertion hole, and the tip can be inserted into the insertion hole on the other end in the extension direction of the insertion hole. having a mounting part that opens to
The inner surface of the mounting portion surrounding the inner space of the insertion hole is
configuring an adhesive application section to which an adhesive for bonding the tip is applied;
Having a concave portion recessed outward so that the adhesive applied to the adhesive application portion is accumulated,
A mounting member that is mounted on the tip of the power cable. The mounting portion has a through hole penetrating from the outer surface of the mounting portion toward the insertion hole,
An attachment member attached to the tip of the power cable according to claim 1 . The through hole is provided so that a fixing member for fixing the tip portion inserted into the insertion hole can be inserted therethrough.
An attachment member attached to the tip portion of the power cable according to claim 2 . The outer surface includes an outer surface positioned around the inner surface of the mounting portion,
The through hole is provided through the mounting portion from the outer surface to the insertion hole,
An attachment member attached to the tip of the power cable according to claim 3. The through hole is provided so that a wedge member that is driven into the end surface of the tip inserted into the insertion hole can be inserted.
An attachment member attached to the tip portion of the power cable according to claim 2 . When the wedge member is driven into the end surface of the tip portion, the wedge member spreads the end surface of the tip portion outward and presses it against the adhesive between the end surface and the inner surface.
An attachment member attached to the tip of the power cable according to claim 5 . The outer surface includes an end surface on one end side in the extending direction of the mounting portion,
The through hole is provided through the mounting portion from the end surface to the insertion hole,
An attachment member attached to the tip of the power cable according to claim 5 or 6. The mounting portion has a receiving portion on the inner surface for receiving an end surface portion of the tip portion,
A mounting member to be mounted on the tip of the power cable according to any one of claims 1 to 7. A spacer provided between the insertion hole and the tip,
An attachment member attached to the tip of the power cable according to any one of claims 1 to 8. It has an insertion hole into which the tip of the power cable is inserted, a traction part is provided on one end in the extension direction of the insertion hole, and the tip is inserted into the insertion hole on the other end in the extension direction of the insertion hole. The mounting portion has an insertable opening, and the inner surface of the mounting portion surrounding the inner space of the insertion hole constitutes an adhesive application portion to which an adhesive for bonding the tip portion is applied. A work method for pulling the power cable using a mounting member having a concave portion recessed outward so that the adhesive applied to the adhesive applied portion is accumulated,
an inserting step of inserting the tip portion into the insertion hole; and an applying step of applying the adhesive to at least one of the tip portion and the inner surface before or after the inserting step; A bonding step of bonding to the mounting part;
a pulling step of pulling the power cable with the pulling portion through the mounting portion after the bonding step;
has a
A working method for pulling the power cable using a mounting member. Having a processing step of processing and forming an uneven shape on the tip before the bonding step,
11. A working method for pulling the power cable using a mounting member according to claim 10.

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