JP2018033204A - Power cable connection part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small power cable connection structure.SOLUTION: A power cable connection part includes: a power cable including a cable conductor; a connection terminal attached to an end part of the cable conductor and integrally molded; an electrode which is embedded in an insulation unit provided so as to be inserted into/removed from the power cable and is electrically and mechanically connected with the connection terminal; a conductive part electrically connecting the connection terminal with the electrode; and an annular coil spring mechanically connecting the connection terminal with the electrode.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a connecting portion of a power cable.

  As a terminal connection portion of a power cable, Patent Document 1 discloses a configuration in which an end portion of a power cable can be inserted and removed from a connection box. Specifically, it includes a male terminal attached to the end of the cable conductor, an embedded conductor provided in the connection box, and a female terminal interposed between the male terminal and the embedded conductor to connect the two. Patent Document 1 discloses a tulip contact as the female terminal.

Japanese Patent Laid-Open No. 10-270101

Miniaturization is desired for the connecting portion of the power cable.
The above-mentioned tulip contact can electrically and mechanically connect the above-mentioned male terminal and the embedded conductor. However, the tulip contact has a large diameter and is a long and large member, and the connecting portion of the power cable using the tulip contact becomes large. Therefore, it is desired to reduce at least one of the size along the radial direction of the power cable and the size along the axial direction in the connecting portion, preferably both.

  Accordingly, an object is to provide a small power cable connection.

The connecting portion of the power cable according to one aspect of the present disclosure is
A power cable with a cable conductor;
A connection terminal attached to the end of the cable conductor and integrally formed;
An electrode embedded in an insulating unit detachably attached to the power cable and electrically and mechanically connected to the connection terminal;
A conductive part that electrically connects the connection terminal and the electrode;
An annular coil spring that mechanically connects the connection terminal and the electrode.

  The connecting portion of the power cable is small.

It is a fragmentary longitudinal cross-section which shows the connection part of the power cable of Embodiment 1. In the connection part of the electric power cable of Embodiment 1, it is a fragmentary longitudinal cross-sectional view which expands and shows the annular coil spring vicinity. It is a longitudinal cross-sectional view of an annular coil spring.

[Description of Embodiment of the Present Invention]
First, the contents of the embodiment of the present invention will be listed and described.
(1) The connecting portion of the power cable according to one aspect of the present invention is
A power cable with a cable conductor;
A connection terminal attached to the end of the cable conductor and integrally formed;
An electrode embedded in an insulating unit detachably attached to the power cable and electrically and mechanically connected to the connection terminal;
A conductive part that electrically connects the connection terminal and the electrode;
An annular coil spring that mechanically connects the connection terminal and the electrode.

  The connection portion of the above power cable has an independent member (conductive portion) for electrical connection and a member (annular coil spring) for mechanical connection between the connection terminal and the electrode provided at the end of the cable conductor. Prepare. Therefore, each member is smaller than the tulip contact. That is, a small-diameter member having a small size along the radial direction of the power cable and a short and small member having a small size along the axial direction of the power cable can be provided. Therefore, the connecting portion of the power cable can be reduced in diameter and shortened as compared with the case where the tulip contact is provided, and is small. In addition, the connecting portion of the power cable is small in size because the connection terminal is an integrally formed product and there is substantially no gap between the divided pieces that is formed when the plurality of divided pieces are assembled. is there. In addition, the connecting portion of the power cable can secure a holding state by the repulsive force of the force that crushes the annular coil spring between the connection terminal and the electrode, and the elasticity of the annular coil spring allows the connection terminal and the electrode to be secured. Plug-in and pull-out operations can be easily performed.

(2) As an example of the connecting portion of the power cable,
The said annular coil spring is a form arrange | positioned in the overlapping location which overlaps in the radial direction of the said power cable in the said connection terminal and the said electrode.

  In the above embodiment, the connection terminal, the electrode, and the annular coil spring are arranged so as to overlap in the radial direction of the power cable. Therefore, the said form can shorten the magnitude | size along the axial direction of the power cable in the connection part of a power cable, and is small.

(3) As an example of the connection part of the power cable of the above (2) in which the connection terminal and the electrode are overlapped,
The connection terminal may be arranged on the inner side than the electrode.

  In addition to being small as described above, for example, the above-described configuration can be easily configured in such a manner that the above three members are overlapped by providing, for example, an insertion hole into which an end of a power cable provided with a connection terminal is fitted. Can be constructed, and is excellent in manufacturability.

(4) As an example of the connection part of the power cable of the above (2) or (3) in which the connection terminal and the electrode are overlapped,
The form provided with the recessed part which forms the cyclic | annular accommodation space where the said cyclic | annular coil spring is arrange | positioned at each of the said duplication location in the said connection terminal and the said duplication location in the said electrode is mentioned.

  According to the above-described configuration, the annular coil spring can be easily positioned with respect to the connection terminal and the electrode, and the annular coil spring is difficult to be removed from the storage space, so that the connection terminal and the electrode can be well secured. In the above configuration, when the connection terminal and the electrode are pulled out, the connection terminal and the electrode are relatively displaced along the axial direction of the power cable, so that the stored state of the annular coil spring can be easily released. Pull out.

(5) As an example of the connecting portion of the power cable of the above (4) having a recess,
An embodiment in which the opening width along the axial direction of the power cable in at least one of the recesses is more than 1 time and less than 2 times the width of the annular coil spring.
The width of the annular coil spring is the axial direction of the ring (the cable conductor of the power cable) when the annular coil spring is not stretched in the circumferential direction of the ring nor in the radial direction of the ring and is in a natural state. The size along the axis direction is substantially coaxial.

  In the above configuration, since the opening width of the concave portion satisfies the above specific range, the annular coil spring is difficult to be removed from the concave portion (storage space), and at the time of the above insertion or withdrawal, the annular coil spring moves inside the concave portion. The sliding resistance can be reduced by moving to some extent. Therefore, the above-mentioned form is easier to secure the above-mentioned retaining state and is more excellent in workability.

(6) As an example of the connection part of the power cable of the above (4) or (5) provided with a recess,
Among the recesses, at least one of the recesses has a bottom part and a wall part connected from the bottom part to the opening part of the recess part,
The wall portion positioned on the distal end side of the connection terminal is inclined with respect to the bottom portion so that the size of the concave portion along the axial direction of the power cable increases from the bottom portion toward the opening portion. The form currently provided is mentioned.

  In the above embodiment, since the opening of the recess is relatively wide, it is easy to store the annular coil spring in the recess, and the sliding resistance at the time of extraction can be reduced by the inclined wall portion, and the workability is also excellent. .

(7) As an example of the connection portion of the power cable of (6) above, which includes an inclined wall portion,
The inclined wall portion may be provided on the connection terminal.

  Here, when providing a recessed part in a connection terminal, cutting the outer peripheral surface of a columnar raw material is mentioned, for example. The said form can form the recessed part of the specific shape of having the wall part inclined with respect to the bottom part easily and accurately by outer periphery cutting, and is excellent also in manufacturability.

(8) As an example of the connection portion of any one of the power cables according to (2) to (7) above, wherein the connection terminal and the electrode are arranged in an overlapping manner,
The form which the space | interval between the said connection terminal and the said electrode in the said duplication location is 0.05 mm or more and 1.0 mm or less is mentioned.

  In the above-described configuration, since the gap in the specific range is provided between the connection terminal and the electrode, the sliding resistance can be reduced by the gap while ensuring the above-described holding state, so that the insertion workability and the extraction can be reduced. Excellent workability.

[Details of the embodiment of the present invention]
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings as appropriate. In the figure, the same reference numerals indicate the same names.

[Embodiment 1]
(Overview)
With reference to FIG. 1, FIG. 2, the connection part 1 of the power cable of Embodiment 1 is demonstrated. In FIG. 1, about the right half of the connection part 1 of a power cable, it is set as the longitudinal cross-sectional view which cut off part of the tub tube part 58, and was cut partially (however, except the power cable 2), and an external appearance is shown in the left half. A longitudinal section is a section cut along a plane parallel to the axial direction of the power cable 2. FIG. 2 is an enlarged view showing the inside of a broken-line circle shown in FIG.

  The power cable connecting portion 1 of the first embodiment is typically provided at a location where the power cable 2 is connected to an external connection target (not shown) such as a power device or an overhead power transmission line. . The connecting portion 1 of the power cable is constructed by attaching an insulating unit 5 containing an electrode 50 that connects the cable conductor 20 and an external connection target to the end of the power cable 2. FIG. 1 illustrates a fully dry air termination connection. The connection portion 1 of the power cable is embedded in a power cable 2 including a cable conductor 20, a connection terminal 3 attached to an end of the cable conductor 20, and an insulation unit 5 provided to be detachable from the power cable 2. The electrode 50 is electrically and mechanically connected to the connection terminal 3. The connection part 1 of the power cable according to the first embodiment is configured such that a member that electrically connects the connection terminal 3 and the electrode 50 and a member that mechanically connects the connection terminal 3 and the electrode are independent members. A conductive portion 6 is provided as a connecting member, and an annular coil spring 4 is provided as a mechanical connecting member. In this example, a cable insertion hole 50 h into which the end of the power cable 2 is fitted is provided at the end of the electrode 50, and a part of the connection terminal 3 and a part of the electrode 50 are in the radial direction of the power cable 2. And the connection terminal 3 is arranged inside the electrode 50. Further, the annular coil spring 4 is disposed at an overlapping portion where the connection terminal 3 and the electrode 50 overlap. Hereinafter, each component will be described in detail.

(Power cable)
The power cable 2 includes a cable conductor 20 and a cable insulator 22 formed on the outer periphery of the cable conductor 20 and includes a high-voltage application having a transmission voltage of 66 kV to 500 kV, for example. In addition, the power cable 2 typically includes a semiconductive layer, a shielding layer, a sheath (all not shown), and the like. Specific examples of the power cable 2 include a CV cable (crosslinked polyethylene insulating sheath cable). In this example, it is a CV cable. The end of the power cable 2 is stripped to expose the cable conductor 20 and the like.

(Connecting terminal)
The connection terminal 3 is a conductive member in which a shaft portion disposed on one end side and a cylindrical portion disposed on the other end side are integrally formed. The shaft portion on one end side is provided with an electrical and mechanical connection portion with the electrode 50, and the tube portion on the other end side is provided with an electrical and mechanical connection portion with the cable conductor 20. The connection terminal 3 of this example includes a blind hole (conductor insertion hole 30) into which the end of the cable conductor 20 is inserted on the other end side.

  In this example, the axial direction (vertical direction in FIG. 1, substantially coaxial with the axial direction of the power cable 2 when attached to the power cable 2) on the outer peripheral surface of the shaft portion on one end side of the connection terminal 3. A coil recess 34 (FIG. 2) and a contact recess 36 are provided apart from each other. The coil recess 34 and the contact recess 36 are both annularly provided continuously in the circumferential direction in the shaft portion on the one end side. The coil recess 34 houses an annular coil spring 4 that mechanically connects the connection terminal 3 and the electrode 50. An annular conductive portion 6 that electrically connects the connection terminal 3 and the electrode 50 is housed in the contact recess 36. In this example, a contact recess 36 is provided on the distal end side of the connection terminal 3. Details of the concave portions 34 and 36, the annular coil spring 4, and the conductive portion 6 will be described later.

  In addition, the connection terminal 3 of this example has a stepped shape in which the outer diameter of the one end side region which is a connection portion with the electrode 50 is narrower than the outer diameter of the other end side region which is a connection portion with the cable conductor 20. Further, in the one end side region, the outer diameter of the tip side region (upper region in FIG. 1) which is an electrical connection portion with the electrode 50 is a root side region (lower side in FIG. 1) which is a mechanical connection portion with the electrode 50. The step shape is smaller than the outer diameter of the side region (see also FIG. 2). Since the shape of the connection terminal 3 is thin in many steps toward the tip, it is easy to perform the insertion and extraction work between the connection terminal 3 and the electrode 50.

  In this example, a conductor insertion hole 30 is provided on the other end side of the connection terminal 3, and the other end side has a bottomed cylindrical shape. By compressing the other end side region of the connection terminal 3 in a state where the end of the cable conductor 20 is inserted into the conductor insertion hole 30, the cable conductor 20 and the connection terminal 3 are electrically connected, and the connection terminal 3 is connected to the connection terminal 3. The cable conductor 20 is pulled and mechanically connected. For the connection structure between the connection terminal 3 and the cable conductor 20, a known technique (eg, a technique using a compression sleeve) can be appropriately referred to.

  Examples of the constituent material of the connection terminal 3, the electrode 50 described later, and the conductive portion 6 include metals having excellent conductivity such as copper, copper alloy, aluminum, and aluminum alloy. By being composed of these metals, the electrical connection can be satisfactorily performed, and the above-described recesses 34 and 36, a later-described recess 54 and the like can be easily formed by cutting.

(Annular coil spring)
The annular coil spring 4 will be described with reference to FIG. FIG. 3 is a vertical cross-sectional view of the annular coil spring 4 cut along a plane parallel to the axial direction (see the dashed line in FIG. 3). The annular coil spring 4 is formed into an annular body (annular body) by forming an obliquely wound metal wire into an annular shape and fixing both ends of the metal wire by welding or the like. In the connection portion 1 of the power cable of the first embodiment, a radial type that applies a spring force so as to expand and contract the annular body in the radial direction (left-right direction in FIG. 3) can be suitably used. As the annular coil spring 4, a known one can be used.

In the annular coil spring 4, the inner diameter r of the annular body may be selected according to the size of the connection terminal 3 and the electrode 50. In this example, since the annular coil spring 4 is interposed at the overlapping portion between the connection terminal 3 and the electrode 50, the inner diameter r of the annular body is equal to the outer diameter on one end side of the connection terminal 3 and the cable insertion hole 50h of the electrode 50. It may be selected according to the inner diameter (described later). The diameter of the metal wire constituting the annular coil spring 4, the width W _{4 of the} annular body (size along the axial direction of the annular body), the height L of the annular body (along the radial direction of the annular body in one turn) Etc.) can be appropriately selected as long as a predetermined retention force can be secured.

  Examples of the constituent material of the annular coil spring 4 include metals such as beryllium copper and stainless steel. In the connection part 1 of the power cable of Embodiment 1, since the electrical connection member (conductive part 6) between the connection terminal 3 and the electrode 50 is separately provided, high electrical conductivity is not required for the annular coil spring 4. Therefore, high strength stainless steel or the like can be used as the constituent material of the annular coil spring 4.

(Insulation unit)
The insulating unit 5 includes an electrode 50 that electrically connects the power cable 2 and an external connection target, and a bushing 52 that is provided on the outer periphery of the electrode 50 and is made of an epoxy resin or the like. The insulating unit 5 of this example further includes a soot tube portion 58 on the outer periphery of the bushing 52. The soot tube portion 58 of this example is an organic composite soot tube comprising an outer shell made of silicone rubber or the like and having a plurality of soots formed thereon. In FIG. 1, as the soot tube portion 58, an example is shown in which large diameter scissors and small diameter scissors are alternately arranged in the axial direction of the soot tube portion 58, but the outer shape can be changed as appropriate. For example, when the connection part 1 of the power cable according to the first embodiment is used as an end-of-gas connection part, the outer shape of the insulating unit 5 can be a smooth shape without unevenness.

  The electrode 50 is a rod-shaped conductive member, and one end portion (not shown, located above in FIG. 1) is a connection location with an external connection target, and the other end region is a connection location with the power cable 2. And In this example, the other end side of the electrode 50 is provided with a cable insertion hole 50h into which an end portion of the power cable 2 to which the connection terminal 3 is attached is inserted, and the other end side has a bottomed cylindrical shape. . Further, the inner diameter of the cable insertion hole 50h differs in multiple stages in correspondence with the external shape of the connection terminal 3 having the above-described multi-level step shape. In the cable insertion hole 50 h, the hole bottom side region facing the tip side of the connection terminal 3 has a minimum diameter, and the opening side region facing the base side of the connection terminal 3 has a maximum diameter. These intermediate diameters are taken in the opposite intermediate regions.

(Conductive part)
The conductive portion 6 is a conductive member for contacting and electrically connecting both the connection terminal 3 and the electrode 50, and has a structure that can be inserted and removed, typically a multipoint contact system. The contact member can be used. A multi-point contact type contact member is typically formed by annularly forming a strip material in which a plurality of spring-like contacts are arranged in parallel, and an example is a multi-ram band (Multi-Contact). The contact member of the multipoint contact method has high current-carrying capacity, is thin while being able to construct a low-resistance connection structure even at a large current, and the width of the strip is relatively short. By using such a contact member for the conductive portion 6, the radial size and the axial size of the power cable 2 in the connecting portion 1 of the power cable can be easily reduced. The conductive portion 6 in this example is a multilam band.

(Electrical connection)
Hereinafter, an electrical connection structure between the connection terminal 3 attached to the cable conductor 20 and the electrode 50 embedded in the insulating unit 5 will be described. In this example, an annular contact concave portion 36 in which the conductive portion 6 is disposed is provided at the distal end portion of the connection terminal 3. The contact recess 36 is provided in a size and shape that can accommodate the conductive portion 6. In particular, the depth of the contact-use recess 36 is such that the connection terminal 3 and the electrode 50 are not connected and the spring-like contact is not crushed by the electrode 50, and the spring-like shape that constitutes the conductive portion 6. A part of the contact is adjusted so as to protrude from the opening of the contact recess 36. In this way, in the state where the connection terminal 3 is inserted into the cable insertion hole 50h of the electrode 50 (hereinafter sometimes referred to as an insertion state), the protruding portion from the contact recess 36 in the spring-like contact The inner peripheral surface of the electrode 50 comes into contact so as to be crushed, so that the electrode 50 and the conductive portion 6 can be electrically connected. In this example, more contact points are provided by providing a total of two electrical connection locations in the axial direction of the connection terminal 3 by combining the contact recess 36 and the annular conductive portion 6. Therefore, a low resistance connection structure can be obtained even for large current applications. Moreover, by adjusting the protrusion amount of the spring-like contactor, the sliding resistance at the time of the above-mentioned insertion or withdrawal is reduced, and the workability is excellent. In a state where the connection terminal 3 is pulled out from the cable insertion hole 50h of the electrode 50 (hereinafter sometimes referred to as a pulled-out state), a part of the spring-like contactor protrudes from the opening of the contactor recess 36. is there.

(Mechanical connection)
Hereinafter, a mechanical connection structure between the connection terminal 3 attached to the cable conductor 20 and the electrode 50 embedded in the insulating unit 5 will be described. In this example, the electrode 50 is provided with the cable insertion hole 50h as described above, and in the above-described insertion state, both of the connection terminals 3 are positioned inside the part of the electrode 50. Overlap in the radial direction of the power cable. The annular coil spring 4 is interposed between the overlapping portions and is sandwiched between the connection terminal 3 and the electrode 50 and is crushed. Using the reaction force of the annular coil spring 4 caused by this crushing, the connection terminal 3 and the electrode 50 are held together. The connection terminal 3 and the electrode 50 are mechanically connected by the retaining force of the annular coil spring 4.

  Further, in this example, as shown in FIG. 2, a recess (coil for coil) that forms an annular storage space in which the annular coil spring 4 is disposed in each of the overlapping portion in the connection terminal 3 and the overlapping portion in the electrode 50. Recesses 34, 54) are provided. In the insertion state described above, the coil recess 34 is provided at a predetermined position on the outer peripheral surface of the connection terminal 3 so that the openings of both the recesses 34 and 54 face each other, and on the inner peripheral surface of the electrode 50. A coil recess 54 is provided at a predetermined position. In the above-described insertion state, an annular storage space is formed by the two concave portions 34 and 54 arranged to face each other. In the above-described insertion state, the annular coil spring 4 is substantially not detached from the storage space, and maintains the mechanical connection between the connection terminal 3 and the electrode 50 by the above-described predetermined retention force.

The size and shape of the coil recesses 34 and 54 can be appropriately selected according to the size and shape of the annular coil spring 4. Since the annular storage space is constituted by both the concave portions 34 and 54, the depths (maximum depths) d ₃ and d ₅ of the concave portions 34 and 54 are smaller than the height L (FIG. 3) of the coil spring 4. Then, the total depth (d ₃ + d ₅ ) may be adjusted so as to be approximately equal to the height L (see also the interval g described later). In particular, the circumferential length of the annular coil spring 4 is preferably slightly longer than the circumferential length of the annular storage space. The depth d is set so that the outer diameter of the annular storage space is slightly smaller than the outer diameter of the annular coil spring 4, for example, about 90% to 95% of the outer diameter of the annular coil spring 4. _3, it is preferable to adjust the _{d 5.} The annular coil spring 4 fitted in such a storage space can be brought into close contact with the inner peripheral surface forming the recesses 34 and 54 by a spring force to increase the diameter, and is difficult to be removed from the storage space.

The depths d ₃ and d ₅ of the coil recesses 34 and 54 may be equal, but it is preferable that the depth of one recess is deeper than the depth of the other recess as in this example. If the annular coil spring 4 is disposed in the deep recess, the above-described retention force can be appropriately generated, and the amount of protrusion from the opening of the deep recess in the annular coil spring 4 can be made smaller than half of the height L. The sliding resistance at the time of the above insertion or withdrawal is reduced, and the workability is excellent. As shown in this example, when the deep concave portion is used as the coil concave portion 54 of the electrode 50 and the insertion work is performed with the annular coil spring 4 fitted in the coil concave portion 54, the outer peripheral surface of the connection terminal 3. The annular coil spring 4 is less likely to come off than the case where the insertion work is performed in a state where the annular coil spring 4 is fitted in the coil recess 34 provided on the coil recess 34, and the workability is excellent.

  The coil recesses 34 and 54 are formed by cutting a predetermined position on the outer peripheral surface of the connection terminal 3 and a predetermined position on the inner peripheral surface of the electrode 50 to provide grooves of a predetermined size and shape. it can.

The opening widths W ₃ and W ₅ along the axial direction of the power cable 2 in at least one of the coil recesses 34 and 54 are more than 1 times the width W ₄ (FIG. 3) of the annular coil spring 4. It can be as follows. If the recess has an opening width that is more than 1 times the width W ₄ of the coil spring 4, even before the insertion, even if the outer diameter of the annular storage space is smaller than the outer diameter of the annular coil spring 4. In addition, the annular coil spring 4 can be easily disposed in the recess. During the insertion operation and the extraction operation, the annular coil spring 4 can be allowed to move to some extent in the axial direction of the power cable 2 in the recess, so that the workability is excellent. In the above insertion state, the crushed annular coil spring 4 can be stored. The larger the opening width is, the easier it is to arrange the annular coil spring 4. However, if the opening width is too large, the allowable movement amount of the annular coil spring 4 is large, and the annular coil spring 4 is appropriately connected by the connection terminal 3 and the electrode 50. There is a risk that it cannot be crushed or the retaining force by the annular coil spring 4 cannot be exhibited properly. If the opening width of the recess and less than twice the width W ₄ of the coil spring 4 can be properly exhibited predetermined anchor force. The opening width of the recess can be set to 1.08 times or more and 1.12 times or less of the width W ₄ of the coil spring 4 in consideration of the above-described retention force and workability. In this example, the opening widths W ₃ and W ₅ of both concave portions 34 and 54 are set to be more than 1 time and less than 2 times the width W ₄ of the coil spring 4.

The longitudinal sectional shape of the coil recesses 34 and 54 can be selected as appropriate. At least one of the concave portions 34 and 35 may have a bottom portion and a wall portion that connects the bottom portion to the opening of the concave portion. In particular, the wall portion located on the distal end side of the connection terminal 3 is provided to be inclined with respect to the bottom so that the size along the axial direction of the power cable 2 in the recess increases from the bottom toward the opening. it can. In FIG. 2, the case where the inclined wall part 34i is provided in the connection terminal 3 is illustrated. Specifically, the connection terminal 3 is disposed on the bottom 34b formed by a flat plane parallel to the axial direction of the connection terminal 3 and on the tip side of the connection terminal 3 (upper side (insertion side in FIG. 2)). A coil recess 34 formed by the wall 34i and the wall 34o on the base side of the connection terminal 3 (in FIG. 2, the lower side (drawing side) and the side closer to the power cable 2) is provided. As the opening width W ₃ of the coil recess 34 is larger than the width W _34b of the bottom portion 34b, the distal end side of the wall portion 34i of the connecting terminal 3 is inclined with respect to the bottom 34b (intersect in a non-orthogonal ) The opening width W ₃ is that wider than the bottom 34b, easily accommodating the coil spring 4. Further, since the wall 34 i positioned on the distal end side of the connection terminal 3 is inclined, for example, when the connection terminal 3 is pulled out from the electrode 50 (or when the electrode 50 is pulled out from the connection terminal 3), the wall 34 i is formed. It is difficult to get caught by the annular coil spring 4. As a result, the resistance during drawing can be reduced and the drawing workability is excellent. The vertical cross-sectional shape of the coil recess 34 in this example is trapezoidal, and the base wall portion 34o of the connection terminal 3 is also inclined with respect to the bottom portion 34b. In this example, the inclination angles of the wall portions 34i and 34o with respect to the bottom portion 34b are made equal, and the coil concave portion 34 has a line-symmetric shape. Opening width W _3, the width W _34b of the bottom portion 34b is preferable to adjust the inclination angle to a predetermined value. When such a trapezoidal coil recess (34) is provided in the connection terminal 3, the coil recess 34 is easily formed. This is because the coil recess 34 can be formed by cutting the outer peripheral surface of the connection terminal 3, and therefore can be easily cut as compared with the case of cutting the inner peripheral surface of the electrode 50.

In this example, the longitudinal sectional shape of the coil recess 54 of the electrode 50 is a pentagon. Specifically, a pair of V-shaped bottom portions and a pair of electrodes 50 arranged so as to be orthogonal to the axial direction of the electrode 50 (vertical direction in FIG. 2, substantially coaxial with the axial direction of the power cable 2 in the above-described insertion state). And a wall. When the annular coil spring 4 is fitted into the coil recess 54, the annular coil spring 4 can be partly in contact with the V-shaped bottom part by positioning it in the V-shaped bottom part. By forming the bottom portion of the recess into which the annular coil spring 4 is fitted in this manner, the predetermined width can be obtained even when the opening width W ₅ is wider than the width W ₄ of the annular coil spring 4 as described above. Positioning can be performed easily and accurately. In addition, the longitudinal cross-sectional shape of the recessed part 54 for coils can be suitably changed into a rectangular shape etc., for example.

  It is preferable to have a slight gap at the overlapping portion between the connection terminal 3 and the electrode 50 because it is easy to reduce resistance during insertion or withdrawal. Although depending on the size of the connecting portion 1 of the power cable, for example, the gap g between the connecting terminal 3 and the electrode 50 at the overlapping portion may be set to 0.05 mm or more and 1.0 mm or less. When the gap g is 0.05 mm or more, the above-mentioned resistance is reduced and the workability is excellent. The larger the gap g, the lower the resistance and the better the workability. By setting the gap g to 1.0 mm or less, the annular coil spring 4 can properly exhibit the retaining force, and the securing state can be secured satisfactorily. . Considering insertion workability, drawing workability, securing of retention force, etc., the interval g can be set to 0.1 mm or more and 0.3 mm or less. In FIG. 2, the gap g is highlighted.

(Other configurations)
1 includes a premolded insulator 8, a compression device (not shown), a mounting bracket 90, a cable protection bracket 94, a corrosion protection layer 98, and the like.
The pre-molded insulator 8 is disposed on the outer periphery of the cable insulator 22 of the power cable 2 and forms a stress cone. The premold insulator 8 is typically made of an epoxy resin or the like. A cylindrical stopper 80 is provided on the front end side (upper side in FIG. 1) of the premolded insulator 8 to define the position of the electrode 50 of the insulating unit 5 along the axial direction of the power cable 2 as a predetermined position. Yes. Even when the electrode 50 comes into contact with the end face of the stopper 80, the tip end face of the connection terminal 3 does not come into contact with the bottom face of the conductor insertion hole 50h of the electrode 50, and a predetermined gap is provided between the bottom face and the tip face. As described above, the length of the stopper 80 is adjusted.
The compression device (not shown) is for pushing the pre-mold insulator 8 into a predetermined position.
The mounting bracket 90 is for mounting the connecting portion 1 of the power cable to a mounting target (not shown) such as an outer wall of a building or a mounting base via a support insulator 92.
The cable protection fitting 94 covers the end portion of the conductor connection tube 96 disposed on the side away from the insulating unit 5 in the power cable 2 (lower side than the attachment fitting 90 in FIG. 1) and houses the above-described compression device. The cylindrical member is fixed to the mounting bracket 90.
The anticorrosion layer 98 is provided so as to integrally cover the end portion of the cable protection fitting 94 and the end portion of the conductor connection pipe 96.

(Manufacturing method of power cable connection part)
For example, the power cable connection unit 1 according to the first embodiment is constructed as follows. When dismantling, the following procedure may be reversed.
1. Terminal processing such as stripping the end of the power cable 2 is performed.
2. The connection terminal 3 is attached to the exposed end portion of the cable conductor 20 by crimping or the like.
3. The conductive portion 6 is fitted into the contact recess 36 of the connection terminal 3. The annular coil spring 4 is fitted into the coil recess 54 of the electrode 50.
4). An insulating unit 5 to which an annular coil spring 4 is attached is fitted into the end of the power cable 2 to which the connection terminal 3 is attached.
For other configurations, known procedures can be referred to.

(effect)
The connection portion 1 of the power cable according to the first embodiment electrically connects the connection terminal 3 attached to the end portion of the cable conductor 20 and the electrode 50 included in the insulating unit 5 attached to the end portion of the power cable 2. A member and a member to be mechanically connected are provided independently. Therefore, compared with the case where a tulip contact having a large diameter and a relatively long length is provided, the connecting portion 1 of the power cable according to the first embodiment is small in size and shortened. Moreover, since the connection part 1 of the power cable of Embodiment 1 uses the connection terminal 3 integrally molded as a component, it is small. And the connection part 1 of the electric power cable of Embodiment 1 can utilize the elasticity of the annular coil spring 4 while ensuring the securing state of the connection terminal 3 and the electrode 50 favorably by the annular coil spring 4. Insertion work and pull-out work can be easily performed, and the workability at the time of construction and disassembly of the connecting portion 1 is excellent.

In addition, the connection part 1 of the power cable of this example has the following effects.
(A) Since the three of the connection terminal 3, the electrode 50, and the annular coil spring 4 are arranged overlapping in the radial direction of the power cable 2, the diameter can be further reduced.
(B) By providing the cable 50 with the cable insertion hole 50h and arranging the connection terminal 3 on the inner side of the electrode 50, the above-described three-way overlapping arrangement can be easily constructed.
(C) Since both the connection terminal 3 and the electrode 50 are provided with the concave portions 34 and 54 that form a storage space for the annular coil spring 4, the annular coil spring 4 is difficult to come off in the inserted state, and the retaining state is maintained. It can be maintained well. Further, by shifting the mutual position of the connection terminal 3 and the electrode 50 along the axial direction of the power cable 2, the stored state of the annular coil spring 4 by both the concave portions 34 and 54 can be easily released, and the drawing workability is improved. Excellent.
(D) Since the opening widths W ₃ , W _{5 of} both the concave portions 34, 54 are more than one time and two times or less of the width W ₄ of the annular coil spring 4, the annular coil spring 4 has the concave portions 34, It is difficult to disengage from 54, exerts a predetermined retaining force, and can maintain the retaining state well. When inserting or withdrawing, the sliding resistance between the connection terminal 3 and the electrode 50 and the annular coil spring 4 is reduced, and the workability is excellent.
(E) Of the wall portions 34i, 34o constituting the coil concave portion 34, the wall portion 34i located on the distal end side of the connection terminal 3 is inclined with respect to the bottom portion 34b. Is easy to get over the wall 34i and to be pulled out.
(F) By providing the inclined wall portions 34i and 34o on the connection terminal 3, the concave portion 34 for the coil can be easily formed, and the productivity is excellent.

[Modification]
About the connection part 1 of the power cable of Embodiment 1, the following at least 1 change is possible.
(1) Applicable to end-of-gas connection.
Thus, the connection part of the power cable provided with the annular coil spring 4 and the conductive part 6 independently can be used in various forms.
(2) A plurality of annular coil springs 4 are provided apart from each other in the axial direction of the power cable 2.
In this case, the retention force by the annular coil spring 4 can be easily increased, and the retained state can be further easily maintained.
(3) The number of the conductive parts 6 is one, or three or more.
In one case, the size of the power cable connection portion 1 along the axial direction of the power cable 2 can be shortened, and further miniaturization can be achieved. In the case of three or more, it can be used for further large current applications.
(4) the depth _{d 3} of the coil recess 34 in the connecting terminals 3, deeper than the depth _{d 5} of the coil recesses 54 in the electrode 50.
Even deeper depth d _3, readily provided by cutting or the like coils recess 34 to the connection terminal 3, excellent manufacturability.
(5) The base wall portion 34o of the connection terminal 3 forming the coil recess 34 is provided so as to be orthogonal to the bottom portion 34b.
In this case, it is easy to restrict the movement of the connection terminal 3 in the pulling direction.
(6) The coil recess 54 in the electrode 50 includes a bottom portion and a wall portion inclined with respect to the bottom portion. Or both the coil recessed parts 34 and 54 are provided with the bottom part and the wall part which inclines with respect to a bottom part. In this case, both the concave portions 34 and 54 can also have a line-symmetric shape.
In any case, when the wall portion located on the distal end side of the connection terminal 3 is inclined, the pulling workability is excellent as described above.

  The present invention is not limited to these exemplifications, but is defined by the scope of claims, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

DESCRIPTION OF SYMBOLS 1 Power cable connection part 2 Power cable 20 Cable conductor 22 Cable insulator 3 Connection terminal 30 Conductor insertion hole 34 Coil recessed part 34b Bottom part 34i, 34o Wall part 36 Contact part recessed part 4 Coil spring 5 Insulation unit 50 Electrode 50h Cable insertion Hole 52 Bushing 54 Recess for coil 58 Steel pipe part 6 Conductive part 8 Premolded insulator 80 Stopper 90 Mounting bracket 92 Support insulator 94 Cable protection metal fitting 96 Conductor connection pipe 98 Corrosion protection layer

Claims (8)

A power cable with a cable conductor;
A connection terminal attached to the end of the cable conductor and integrally formed;
An electrode embedded in an insulating unit detachably attached to the power cable and electrically and mechanically connected to the connection terminal;
A conductive part that electrically connects the connection terminal and the electrode;
A connecting portion of a power cable comprising: the connection terminal and an annular coil spring that mechanically connects the electrodes.   The said annular coil spring is a connection part of the power cable of Claim 1 arrange | positioned in the overlapping location which overlaps in the radial direction of the said power cable in the said connection terminal and the said electrode.   The connection portion of the power cable according to claim 2, wherein the connection terminal is disposed inside the electrode.   The electric power cable according to claim 2 or 3 provided with the crevice which forms the annular storage space where said annular coil spring is arranged in each of said overlapping part in said connecting terminal and said overlapping part in said electrode. Connection part.   5. The power cable connecting portion according to claim 4, wherein an opening width along an axial direction of the power cable in at least one of the recesses is more than 1 time and less than 2 times a width of the annular coil spring. . Among the recesses, at least one of the recesses has a bottom part and a wall part connected from the bottom part to the opening part of the recess part,
The wall portion positioned on the distal end side of the connection terminal is inclined with respect to the bottom portion so that the size of the concave portion along the axial direction of the power cable increases from the bottom portion toward the opening portion. The connection part of the electric power cable of Claim 4 or Claim 5 provided.   The power cable connection portion according to claim 6, wherein the inclined wall portion is provided on the connection terminal.   The connection part of the power cable of any one of Claims 2-7 whose space | interval between the said connection terminal and the said electrode in the said duplication location is 0.05 mm or more and 1.0 mm or less.

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