Sleeve and method for connecting electric wire

Abstract

To provide a sleeve capable of easily releasing inside an expansion force generated in a stranded wire against a compression force while applying the compression force to the stranded wire of an electric wire by a compression part.SOLUTION: The sleeve 1 includes an inner cylinder 5 and an outer cylinder 6 covering the outside of the inner cylinder 5. The inside of the one side portion 7 of the inner tube 5 is used for inserting an end 2A of one wire 20A from which the stranded wire 3 is exposed. The inside of the other side portion 8 of the inner tube 5 is used for inserting an end 2B of the other wire 20B from which the stranded wire 3 is exposed. In each of the first and second intermediate sections 11, 12 of the outer tube 6, a compressed portion 30 to be compressed when connecting the two wires 2A, 2B and a non-compressed portion 31 having an outer diameter different from that of the compressed portion 30 and not to be compressed when connecting the two wires 2A, 2B are alternately formed in the longitudinal direction.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a sleeve and a method for connecting two electrical wires using the sleeve. [Background technology]

[0002] Conventionally, electric wires have been used as power transmission lines, which include a twisted wire in which a plurality of conductive wires are bound together, and an insulating coating that covers the twisted wire. Patent Document 1 discloses that the twisted wire is made of a twisted wire in which a plurality of aluminum conductors (strands) are twisted together around a center wire, and that the coating is made of a vinyl or polyethylene material.

[0003] Conventionally, a sleeve 100 shown in Fig. 13 has been used to connect two of the above-mentioned electric wires. The sleeve 100 is made of aluminum and has a cylindrical shape with both ends open. When connecting two electric wires 101A and 101B using the sleeve 100, the following first electric wire insertion step, first compression step, second electric wire insertion step, and second compression step are carried out in this order (Fig. 14 shows a state in which the two electric wires 101A and 101B are connected by the sleeve 100 as a result of carrying out the following first electric wire insertion step, first compression step, second electric wire insertion step, and second compression step).

[0004] First wire insertion step: End portion 113A of one electric wire 110A, from which coating 111 has been stripped to expose stranded wire 112, is inserted into one side portion 101 of sleeve 100. First compression step: The entire width of one side 101 of the sleeve 100 is compressed radially, and one side 101 of the sleeve 100 is brought into close contact with the end 113A of one electric wire 110A, thereby connecting one electric wire 110A to the sleeve 100. Second electric wire insertion step: End portion 113B of other electric wire 110B, from which coating 111 has been stripped to expose stranded wire 112, is inserted into other side portion 102 of sleeve 100. Second compression step: The entire width of the other side 102 of the sleeve 100 is compressed radially, and the other side 102 of the sleeve 100 is brought into close contact with the end 113B of the other electric wire 110B, thereby connecting the other electric wire 110B to the sleeve 100. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Utility Model Registration No. 3223576 Summary of the Invention [Problem to be solved by the invention]

[0006] According to the above-described conventional method for connecting electric wires using the sleeve 100, the entire width of one side 101 of the sleeve 100 is compressed in the first compression step, so that the expansion force generated in the stranded wires 112 of the electric wire 110A against the compression force is transmitted to and accumulated in the range of the stranded wires 112 of the electric wire 110A located outside the sleeve 100 (the range of the stranded wires 112 of the electric wire 110A covered with the coating 111) without being released inside the sleeve 100. Furthermore, the entire width of the other side 102 of the sleeve 100 is compressed in the second compression step, so that the expansion force generated in the stranded wires 112 of the electric wire 110B against the compression force is transmitted to and accumulated in the range of the stranded wires 112 of the electric wire 110B located outside the sleeve 100 (the range of the stranded wires 112 of the electric wire 110B covered with the coating 111) without being released inside the sleeve 100.

[0007] As described above, the expansion force accumulates in the range of the stranded wires 112 of the electric wires 110A, 110B positioned outside the sleeve 100 (the range of the stranded wires 112 of the electric wires 110A, 110B covered with the coating 111). When the coating 111 is stripped off at the other end of the electric wires 110A, 110B to expose the stranded wires 112 in order to connect the electric wires 110A, 110B to another electric wire using another sleeve 100, the exposed stranded wires 112 are subjected to the expansion force. (FIG. 14 shows a state in which, when the covering 111 is stripped off at the other end 114B of the electric wire 110B to expose the stranded wire 112 in order to connect the electric wires 110A, 110B to another electric wire using another sleeve 100 (the right sleeve 100 of the two sleeves 100, 100 shown in FIG. 14), the stranded wire 112 at the exposed end 114B expands due to the expansion force.) When this "fray" phenomenon occurs, it becomes difficult to insert the other end of the electric wires 110A, 110B into the other sleeve 100, making it difficult to connect the electric wires 110A, 110B to another electric wire. To avoid this problem, a sleeve capable of releasing the expansion force internally is needed.

[0008] The present invention has been made in consideration of the above-mentioned problems, and an object of the present invention is to provide a sleeve used for connecting two electric wires, each of which has a twisted wire formed by bundling a plurality of conductive wires together and an electrically insulating coating that covers the twisted wire, and which is capable of distinguishing between a compression section that compresses when connecting the two electric wires and a non-compression section that does not compress, so that a compressive force can be applied to the twisted wires of the electric wires in the compression section, while easily releasing the expansion force generated in the twisted wire against the compressive force inside the sleeve.

[0009] Another object of the present invention is to provide a method for connecting two electric wires using a sleeve, which is capable of applying a compressive force to the stranded wires of the electric wires with the compression portion of the sleeve, while releasing the expansion force generated in the stranded wires against the compressive force inside the sleeve. [Means for solving the problem]

[0010] To achieve the above object, the present invention includes the following subject matter.

[0011] Item 1. A sleeve used to connect two electric wires, each of which has a stranded wire made of a plurality of conductive wires bound together and an electrically insulating coating that covers the periphery of the stranded wire, an inner cylinder formed from a conductive material; an outer cylinder formed from an electrically insulating material; The inner cylinder is disposed inside the outer cylinder, the outer cylinder has a structure in which a first protruding portion protruding to one side beyond one side end of the inner cylinder, a first intermediate portion covering the outside of one side of the inner cylinder, a second intermediate portion covering the outside of the other side of the inner cylinder, and a second protruding portion protruding to the other side beyond the other side end of the inner cylinder are connected in sequence, an inside of one side portion of the inner cylinder is used for inserting an end portion of the one electric wire from which the coating has been stripped to expose the stranded wires; At least a part of the inside of the first protrusion is used to insert a subsequent portion of the one electric wire whose coating is not stripped, the inside of the other side portion of the inner tube is used for inserting an end portion of the other electric wire from which the coating has been stripped to expose the stranded wire, At least a part of the inside of the second protrusion is used to insert a subsequent part of the other electric wire whose coating is not stripped, The first intermediate portion and the second intermediate portion are sleeves in which compressed portions that are compressed when connecting the two electric wires and non-compressed portions that have an outer diameter or outer surface color different from the compressed portions and are not compressed when connecting the two electric wires are alternately formed in the longitudinal direction.

[0012] Item 2. The sleeve according to Item 1, wherein the non-compressed portion has an outer diameter larger than the compressed portion.

[0013] Item 3. The sleeve according to item 1 or 2, wherein the longitudinal width of the uncompressed portion is smaller than the longitudinal width of the compressed portion.

[0014] Item 4. The inner cylinder is formed from aluminum, an aluminum alloy, copper, or a copper alloy as the conductive material; 4. The sleeve according to any one of items 1 to 3, wherein the outer cylinder is made of a resin as the electrically insulating material.

[0015] Item 5. A method for connecting the two electric wires using the sleeve according to any one of items 1 to 4, a first wire insertion step of inserting the one electric wire into the first protruding portion and into the one side portion of the inner cylinder; a first intermediate portion compressing step of radially compressing each of the compressed portions in the first intermediate portion; a second wire insertion step of inserting the other electric wire into the second protruding portion and the other side portion of the inner tube; a second intermediate portion compressing step of compressing each of the compressed portions in the second intermediate portion in a radial direction, In the first electric wire insertion step, an end portion of the one electric wire, from which the coating is stripped to expose the stranded wire, is inserted into one side portion of the inner tube, and a subsequent portion of the one electric wire, from which the coating is not stripped, is inserted into the first protruding portion, In the first intermediate portion compressing step, one compressed portion in the first intermediate portion is compressed from the other side to the one side without compressing the non-compressed portion adjacent to the one compressed portion in the first intermediate portion, so that each compressed portion in the first intermediate portion is compressed without compressing each non-compressed portion in the first intermediate portion, and one side portion of the inner tube is brought into close contact with the end of the one electric wire, and the one electric wire is connected to the sleeve, In the second electric wire insertion step, an end portion of the other electric wire, from which the coating is stripped to expose the stranded wire, is inserted into the other side portion of the inner tube, and a subsequent portion of the other electric wire, from which the coating is not stripped, is inserted into the second protruding portion, In the second intermediate portion compression process, one compressed portion in the second intermediate portion is compressed from one side to the other without compressing the non-compressed portion adjacent to the one compressed portion in the second intermediate portion, so that each of the compressed portions in the second intermediate portion is compressed without compressing each of the non-compressed portions in the second intermediate portion, so that the other side of the inner tube is in close contact with the end of the other electric wire, and the other electric wire is connected to the sleeve.

[0016] Item 6. In the first electric wire insertion step, an end of the one electric wire, from which the coating is stripped to expose the stranded wire, is inserted into the inside of one side of the inner tube and the inside of the other side of the first protruding portion, and a subsequent portion of the one electric wire, from which the coating is not stripped, is inserted into the inside of the one side of the first protruding portion, Item 6. The electric wire connecting method according to Item 5, wherein in the second electric wire inserting step, an end of the other electric wire, from which the coating has been stripped to expose the stranded wire, is inserted into the inside of the other side part of the inner tube and the inside of one side of the second protruding part, and a subsequent part of the other electric wire, from which the coating has not been stripped, is inserted into the inside of the other side of the second protruding part.

[0017] Item 7. The first intermediate portion compressing step and the second intermediate portion compressing step are each performed using a pair of metal compression tools; In each of the first intermediate portion and the second intermediate portion, the compressed portions and the non-compressed portions having an outer diameter larger than that of the compressed portions are alternately formed in the longitudinal direction, Each of the compression tools has a groove formed therein that is deeper on both outer sides than on the center of the width, In the first intermediate portion compressing step, compressing one compressed portion in the first intermediate portion without compressing the non-compressed portion adjacent to the one compressed portion in the first intermediate portion is achieved by pressing the pair of compression tools against the first intermediate portion with the grooves of the pair of compression tools facing each other and the first intermediate portion positioned between the pair of compression tools so that the one compressed portion of the first intermediate portion is located at the center of the width of the groove of each of the compression tools and the non-compressed portion adjacent to the one compressed portion of the first intermediate portion is located outside the width of the groove of each of the compression tools, and until the peripheral surfaces of the grooves of the pair of compression tools abut against each other, the one compressed portion of the first intermediate portion is compressed by the bottom surface at the center of the width of the groove of each of the compression tools, but the non-compressed portion adjacent to the one compressed portion of the first intermediate portion is not compressed, 7. The method for connecting electric wires according to item 5 or 6, wherein in the second intermediate portion compressing step, compressing one compressed portion in the second intermediate portion without compressing the non-compressed portion adjacent to one of the compressed portions in the second intermediate portion is achieved by pressing the pair of compression tools against the second intermediate portion with the grooves of the pair of compression tools facing each other and the second intermediate portion positioned between the pair of compression tools so that the one compressed portion of the second intermediate portion is located at the center of the width of the groove of each of the compression tools and the non-compressed portion adjacent to the one compressed portion of the second intermediate portion is located outside the width of the groove of each of the compression tools, and until the peripheral surfaces of the grooves of the pair of compression tools abut against each other, the one compressed portion of the second intermediate portion is compressed by the bottom surface at the center of the width of the groove of each of the compression tools but the non-compressed portion adjacent to the one compressed portion of the second intermediate portion is not compressed. [Effects of the Invention]

[0018] According to the sleeve of the present invention, it is possible to easily apply a compressive force to the stranded wires of the electric cable at the compression portion, while releasing the expansion force generated in the stranded wires against the compressive force inside.

[0019] According to the electric wire connecting method of the present invention, a compressive force is applied to the stranded wires of the electric wires by the compression portion of the sleeve, and the expansion force generated in the stranded wires against the compressive force can be released inside the sleeve. [Brief explanation of the drawings]

[0020] [Figure 1] FIG. 2 is a side view showing a sleeve according to an embodiment of the present invention. [Figure 2] FIG. 2 is a longitudinal cross-sectional view showing a sleeve according to an embodiment of the present invention. [Figure 3] FIG. 1 is a vertical cross-sectional view showing a state in which two electric wires are connected using a sleeve according to an embodiment of the present invention. [Figure 4] 10A and 10B are longitudinal cross-sectional views showing a first wire insertion step, (C), (D), (E), and (F) are side views showing a first intermediate portion compression step, (G) is a side view showing a first protruding portion compression step, and (H) is a longitudinal cross-sectional view showing a state in which one wire is connected to the sleeve. [Figure 5] 10A and 10B are longitudinal cross-sectional views showing the second wire insertion step, (C), (D), (E), and (F) are side views showing the second intermediate portion compression step, (G) is a side view showing the second protruding portion compression step, and (H) is a longitudinal cross-sectional view showing the state in which the two wires are connected to the sleeve. [Figure 6] 1A is a perspective view showing the fixture as viewed from above, and FIG. 1B is a perspective view showing the fixture as viewed from below. [Figure 7] (A1) is a side view showing the state of the sleeve when the first intermediate portion of the outer tube is positioned between a pair of compression tools and before the pair of compression tools are pressed against the first intermediate portion, (A2) is a cross-sectional view of (A1) taken along line AA, (A3) is a cross-sectional view of (A1) taken along line BB, (B1) is a side view showing the state of the sleeve when the pair of compression tools begin to be pressed against the first intermediate portion, (B2) is a cross-sectional view of (B1) taken along line AA, (B3) is a cross-sectional view of (B1) taken along line BB, (C1) is a side view showing the state of the sleeve when the pair of compression tools have been pressed against the first intermediate portion, (C2) is a cross-sectional view of (C1) taken along line AA, and (C3) is a cross-sectional view of (C1) taken along line BB. [Figure 8] FIG. 10 is a vertical cross-sectional view showing the state of the sleeve when the first intermediate portion compression step is completed. [Figure 9] FIG. 10 is a vertical cross-sectional view showing the state of the sleeve when the second intermediate portion compression step is completed. [Figure 10] 10 is a longitudinal cross-sectional view showing a state in which the coating is stripped away to expose the stranded wire at the end of the other electric wire connected to the sleeve according to the embodiment of the present invention. FIG. [Figure 11] FIG. 1 is a vertical cross-sectional view showing a state in which two electric wires are connected using a sleeve according to an embodiment of the present invention. [Figure 12] FIG. 1 is a vertical cross-sectional view showing a state in which two electric wires are connected using a sleeve according to an embodiment of the present invention. [Figure 13] 1A and 1B are diagrams showing a conventional sleeve, in which (A) is a side view and (B) is a longitudinal cross-sectional view. [Figure 14] FIG. 10 is a longitudinal cross-sectional view showing a state in which, when the coating is stripped off to expose the stranded wire at the end of the other wire connected to a conventional sleeve, the "Warai" phenomenon occurs, in which the exposed stranded wire swells due to expansion force. DETAILED DESCRIPTION OF THE INVENTION

[0021] <Embodiment> Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0022] Fig. 1 is a side view showing a sleeve 1 according to an embodiment of the present invention. Fig. 2 is a longitudinal sectional view showing the sleeve 1 according to an embodiment of the present invention. Fig. 3 is a longitudinal sectional view showing a state in which two electric wires 2A and 2B are connected using the sleeve 1 according to an embodiment of the present invention.

[0023] A sleeve 1 according to an embodiment of the present invention is used to connect two electric wires 2A and 2B. Each of the two electric wires 2A and 2B includes a stranded wire 3 formed by bundling a plurality of conductive wires together, and an electrically insulating tubular covering 4 that covers the periphery of the stranded wire 3. For example, an ACSR (Aluminum Stranded Conductor Steel Reinforced) electric wire in which a plurality of aluminum conductors (strands) are stranded around a central wire made of steel is used as the stranded wire 3. For example, a tubular body made of rubber, vinyl, or polyethylene material is used as the covering 4.

[0024] The sleeve 1 comprises an inner tube 5 and an outer tube 6, and the inner tube 5 is disposed inside the outer tube 6 (the inner tube 5 is covered by the outer tube 6). In this application, "one side in the longitudinal direction of the sleeve 1" will be referred to as "one side," "the other side in the longitudinal direction of the sleeve 1" will be referred to as "the other side," and "the radial direction of the sleeve 1" will be referred to as "radial direction."

[0025] The inner cylinder 5 has a cylindrical shape with both ends open and is made of a conductive material. Examples of the conductive material that can be used to form the inner cylinder 5 include metals such as aluminum, aluminum alloys, copper, and copper alloys.

[0026] The interior of one side portion 7 of the inner tube 5 is used to insert an end portion 20A of one electric wire 2A, from which the coating 4 has been stripped to expose the stranded wires 3. The interior of the other side portion 8 of the inner tube 5 is used to insert an end portion 20B of the other electric wire 2B, from which the coating 4 has been stripped to expose the stranded wires 3. A partition wall 9 is formed inside the inner tube 5 at the boundary between the one side portion 7 and the other side portion 8 (i.e., the interior of the inner tube 5 is divided into the interior of the one side portion 7 and the interior of the other side portion 8 by the partition wall 9). In the illustrated example, the partition wall 9 is provided at the center of the length of the inner tube 5, so that the interior lengths of the one side portion 7 and the other side portion 8 are each approximately half the length of the inner tube 5. However, the present invention is not limited to providing the partition wall 9 at the center of the length of the inner tube 5, and the partition wall 9 can be provided at any position on the inner tube 5. Furthermore, the partition wall 9 is not necessarily required and may be omitted. In this case, "one side 7 of the inner tube 5" corresponds to "the range of the inner tube 5 into which the end 20A of one electric wire 2A, from which the coating 4 has been stripped to expose the twisted wire 3, is inserted," and "the other side 8 of the inner tube 5" corresponds to "the range of the inner tube 5 into which the end 20B of the other electric wire 2B, from which the coating 4 has been stripped to expose the twisted wire 3, is inserted."

[0027] The outer cylinder 6 has a cylindrical shape with both ends open, and is made of an electrically insulating material, such as a resin such as engineering plastic.

[0028] The outer tube 6 has a structure in which a first protruding portion 10 protruding to one side beyond one side end 50 (Figure 2) of the inner tube 5, a first intermediate portion 11 covering the outside of one side portion 7 of the inner tube 5, a second intermediate portion 12 covering the outside of the other side portion 8 of the inner tube 5, and a second protruding portion 13 protruding to the other side beyond the other side end 51 (Figure 2) of the inner tube 5 are connected in sequence.

[0029] In the illustrated example, the inner diameter of one end 52 of one side portion 7 of the inner tube 5 increases toward one side, so that the inner diameter of one side end 50 of the inner tube 5 matches the inner diameter of the first protruding portion 10, and the inner diameter of a range 53 other than the one end 52 on one side portion 7 of the inner tube 5 is smaller than the inner diameter of the first protruding portion 10; however, the inner diameter of one side portion 7 of the inner tube 5 may be kept constant over the entire length of the one side portion 7 of the inner tube 5, and the inner diameter of the first protruding portion 10 may be larger than the inner diameter of the one side portion 7 of the inner tube 5. In the illustrated example, the inner diameter of the other end 54 of the other side portion 8 of the inner tube 5 increases toward the other side, so that the inner diameter of the other side end 51 of the inner tube 5 matches the inner diameter of the second protruding portion 13, and the inner diameter of the range 55 other than the other end 54 on the other side portion 7 of the inner tube 5 is smaller than the inner diameter of the second protruding portion 13; however, the inner diameter of the other side portion 8 of the inner tube 5 may be kept constant over the entire length of the other side portion 8 of the inner tube 5, and the inner diameter of the second protruding portion 13 may be larger than the inner diameter of the other side portion 8 of the inner tube 5.

[0030] At least a part of the interior of the first protrusion 10 is used for inserting the trailing portion 21A of one electric wire 2A from which the coating 4 is not stripped. More specifically, the "interior on one side 10A of the first protrusion 10" is used for inserting the above-mentioned "trailing portion 21A of one electric wire 2A from which the coating 4 is not stripped," and the "interior on the other side 10B of the first protrusion 10" is used for inserting the "other side of the end 20A of one electric wire 2A from which the stranded wires 3 are exposed." The above-mentioned "trailing portion 21A of one electric wire 2A" means "the portion following the end 20A of one electric wire 2A."

[0031] At least a part of the inside of the second protrusion 13 is used for inserting the trailing portion 21B of the other electric wire 2B from which the coating 4 is not stripped. More specifically, the "inside of the other side 13A of the second protrusion 13" is used for inserting the above-mentioned "trailing portion 21B of the other electric wire 2B from which the coating 4 is not stripped," and the "inside of one side 13B of the second protrusion 13" is used for inserting the "other side of the end 20B of the other electric wire 2B from which the stranded wires 3 are exposed." The above-mentioned "trailing portion 21B of the other electric wire 2B" means "the portion following the end 20B of the other electric wire 2B."

[0032] In each of the first intermediate portion 11 and the second intermediate portion 12, compressed portions 30 that are compressed when connecting the two electric wires 2A, 2B and non-compressed portions 31 that are not compressed when connecting the two electric wires 2A, 2B are alternately formed in the longitudinal direction, and the compressed portions 30 and the non-compressed portions 31 have different outer diameters, making them distinguishable from each other. In this embodiment, the outer diameter of the non-compressed portions 31 is larger than the outer diameter of the compressed portions 30, but the outer diameter of the non-compressed portions 31 may be smaller than the outer diameter of the compressed portions 30.

[0033] In order to keep the length of the sleeve 1 short, it is preferable that the width H1 (FIG. 2) of the non-compressed portion 31 in the longitudinal direction is smaller than the width H2 of the compressed portion 30 in the longitudinal direction.

[0034] The above-mentioned sleeve 1 is obtained by forming the inner tube 5 from a conductive material (for example, by cutting a cylindrical body made of a conductive material to form the inner tube 5), placing the inner tube 5 in a mold, injecting an electrically insulating material into the mold, and injection-molding the outer tube 6 around the inner tube 5.

[0035] FIG. 4 shows a procedure for connecting one electric wire 2A to the sleeve 1, and FIG. 5 shows a procedure for connecting the other electric wire 2B to the sleeve 1. As shown in FIG.

[0036] When connecting two electric wires 2A, 2B using the sleeve 1, first, as shown in Figures 4(A) and 4(B), a first electric wire insertion step is performed in which one electric wire 2A is inserted into the first protruding portion 10 and into one side portion 7 of the inner tube 5. In this first electric wire insertion step, "the end portion 20A of the one electric wire 2A from which the coating 4 has been stripped to expose the stranded wires 3" is inserted into "the one side portion 7 of the inner tube 5 and the other side 10B of the first protruding portion 10," and "the subsequent portion 21A of the one electric wire 2A from which the coating 4 has not been stripped" is inserted into "the one side 10A of the first protruding portion 10."

[0037] After the first electric wire insertion step is performed, a first intermediate portion compression step (FIGS. 4(C) to 4(F)) is performed in which each of the compressed portions 30 in the first intermediate portion 11 is compressed. In this first intermediate portion compression step, one compressed portion 30 in the first intermediate portion 11 is compressed from the other side to one side without compressing the non-compressed portion 31 adjacent to that compressed portion 30, so that each of the compressed portions 30 in the first intermediate portion 11 is compressed without compressing each of the non-compressed portions 31 in the first intermediate portion 11. This compression brings one side portion 7 of the inner tube 5 into close contact with the end portion 20A of one electric wire 2A, and the one electric wire 2A is connected to the sleeve 1.

[0038] The first intermediate portion compression step is performed using, for example, a pair of compression tools 40, 40. Each compression tool 40 is made of metal such as steel, and as shown in Fig. 6, each compression tool 40 has grooves 43 formed on both widthwise outer sides 41, 41 that are deeper than the widthwise center 42.

[0039] 7, when the compression tools 40 are used, the grooves 43 of the pair of compression tools 40 face each other, and the first intermediate portion 11 of the outer tube 6 is positioned between the pair of compression tools 40. The pair of compression tools 40 are then pressed against the first intermediate portion 11 so that one compressed portion 30 of the first intermediate portion 11 is positioned in the width center 42 of the groove 43 of each compression tool 40, and the non-compressed portion 31 adjacent to the one compressed portion 30 of the first intermediate portion 11 is positioned on the width outer side 41 of the groove 43 of each compression tool 40. This pressing is performed until the peripheral surfaces 44 of the grooves 43 of the pair of compression tools 40 come into contact with each other. As described above, in each compression tool 40, the widthwise outer side 41 of the groove 43 is recessed deeper than the widthwise center 42 of the groove 43, so that while the above-mentioned pressing is being performed (i.e., until the surfaces 44, 44 of the pair of compression tools 40 abut against each other), the bottom surface 45 of the widthwise center 42 of the groove 43 of each compression tool 40 compresses one compressed portion 30 of the first intermediate portion 11, but does not compress the non-compressed portion 31 adjacent to the one compressed portion 30 of the first intermediate portion 11, thereby achieving the above-mentioned "compressing one compressed portion 30 without compressing the non-compressed portion 31 adjacent to the one compressed portion 30 in the first intermediate portion 11." Then, by performing the compression operation using the compression tool 40 from the other side of the first intermediate portion 11 to one side, it is possible to compress each compressed portion 30 in the first intermediate portion 11 without compressing each non-compressed portion 31 in the first intermediate portion 11. In the illustrated example, when the surfaces 44, 44 of the pair of compression tools 40 are in contact with each other, the cross section of the space formed by combining the width centers 42, 42 of the grooves 43, 43 of the pair of compression tools 40, 40 is a hexagon that is smaller than the cross section of the compression section 30, but the cross section of the space formed by combining the width centers 42, 42 may be any shape that is smaller than the cross section of the compression section 30. Furthermore, the cross section of the space formed by combining the width outer sides 41, 41 of the grooves 43, 43 of the pair of compression tools 40, 40 is circular, the same as the cross section of the non-compression section 31, but the cross section of the space formed by combining the width outer sides 41, 41 may have a shape (for example, circular) larger than the cross section of the compression section 30.

[0040] 8 is a vertical cross-sectional view showing the state of the sleeve 1 when the first intermediate portion compressing step is completed. According to the first intermediate portion compressing step described above, each of the compressed portions 30 in the first intermediate portion 11 is compressed without compressing each of the non-compressed portions 31 in the first intermediate portion 11. Therefore, a "wrapper" phenomenon, in which the stranded wires 3 of the electric wire 2A expand due to an expansion force that resists the compression force, occurs at a position inside the inner tube 5, inside each of the non-compressed portions 31 in the first intermediate portion 11, and the expansion force is released at that position.

[0041] The example in Figure 4 shows a case where, after the above-mentioned first intermediate portion compression step (Figures 4(C) to 4(F)), a first protrusion compression step (Figure 4(G)) is performed in which one side 10A of the first protrusion 10 is radially compressed using a pair of compression tools 40, 40 to bring one side 10A of the first protrusion 10 into close contact with the subsequent portion 21A of one electric wire 2A, but this first protrusion compression step is not necessarily required and may be omitted.

[0042] After the first intermediate portion compressing step or the first protruding portion compressing step is performed, a second electric wire inserting step is performed in which the other electric wire 2B is inserted into the second protruding portion 13 and the other side portion 8 of the inner tube 5, as shown in Figures 5(A) and 5(B). In this second electric wire inserting step, "the end portion 20B of the other electric wire 2B from which the coating 4 has been stripped to expose the stranded wire 3" is inserted into "the other side portion 8 of the inner tube 5 and the one side 13B of the second protruding portion 13", and "the subsequent portion 21B of the other electric wire 2B from which the coating 4 has not been stripped" is inserted into "the other side 13A of the second protruding portion 13".

[0043] After the second electric wire insertion step is performed, a second intermediate portion compression step is performed in which each of the compressed portions 30 in the second intermediate portion 12 is compressed in the radial direction. In this second intermediate portion compression step, one compressed portion 30 in the second intermediate portion 12 is compressed from one side to the other without compressing the non-compressed portion 31 adjacent to that compressed portion 30, so that each of the compressed portions 30 in the second intermediate portion 12 is compressed without compressing each of the non-compressed portions 31 in the second intermediate portion 12. This compression brings the other side portion 8 of the inner tube 5 into close contact with the end portion 20B of the other electric wire 2B, and the other electric wire 2B is connected to the sleeve 1.

[0044] The second intermediate portion compressing step is also carried out using, for example, a pair of compressing tools 40, 40 (FIG. 6) in the same manner as the first intermediate portion compressing step.

[0045] When the above-described compression tools 40 are used, the pair of compression tools 40 are pressed against the second intermediate portion 12 with the grooves 43 of the pair of compression tools 40 facing each other and the second intermediate portion 12 of the outer cylinder 6 positioned between the pair of compression tools 40 so that one compressed portion 30 of the second intermediate portion 12 is positioned in the width center 42 of the groove 43 of each compression tool 40 and the non-compressed portion 31 adjacent to one compressed portion 30 of the second intermediate portion 12 is positioned on the width outer side 41 of the groove 43 of each compression tool 40. This pressing is performed until the peripheral surfaces 44 of the grooves 43 of the compression tools 40 abut against each other. In each compression tool 40, the widthwise outer side 41 of the groove 43 is recessed deeper than the widthwise center 42 of the groove 43, so that while the above-mentioned pressing is being performed (i.e., until the surfaces 44, 44 of the pair of compression tools 40 abut against each other), the bottom surface 45 of the widthwise center 42 of the groove 43 of each compression tool 40 compresses one compressed portion 30 of the second intermediate portion 12 but does not compress the non-compressed portion 31 adjacent to the one compressed portion 30 of the second intermediate portion 12, thereby achieving the above-mentioned "compressing one compressed portion 30 without compressing the non-compressed portion 31 adjacent to the one compressed portion 30 in the second intermediate portion 12." Then, by performing the compression operation using the compression tool 40 from one side of the second intermediate portion 12 to the other, it is possible to compress each compressed portion 30 in the second intermediate portion 12 without compressing each non-compressed portion 31 in the second intermediate portion 12.

[0046] 9 is a vertical cross-sectional view showing the state of the sleeve 1 when the first intermediate portion compressing step is completed. According to the second intermediate portion compressing step described above, each of the compressed portions 30 in the second intermediate portion 12 is compressed without compressing each of the non-compressed portions 31 in the second intermediate portion 12. Therefore, a "wrapper" phenomenon, in which the stranded wires 3 of the electric wire 2B expand due to an expansion force that resists the compression force, occurs at a position inside the inner tube 5 inside each non-compressed portion 31 of the second intermediate portion 12, and the expansion force is released at that position.

[0047] The example in Figure 5 shows a case where, after the above-mentioned second intermediate portion compression step (Figures 5(C) to 5(F)), the second protrusion compression step (Figure 5(G)) is performed in which the other side 13A of the second protrusion 13 is radially compressed using the compression tool 40 to bring the other side 13A of the second protrusion 13 into close contact with the subsequent portion 21B of the other electric wire 2B, but this second protrusion compression step is not necessarily required and may be omitted.

[0048] The method for connecting the electric wires 2A and 2B according to this embodiment is completed after the second intermediate portion compressing step or the second protruding portion compressing step is performed. At this time, the two electric wires 2A and 2B are connected via the sleeve 1, and the stranded wires 3 of the two electric wires 2A and 2B are electrically connected via the conductive inner tube 5, as shown in Figs. 3 and 5(H).

[0049] According to the above embodiment, the compression section 30, which is compressed when connecting the two electric wires 2A, 2B, and the non-compression section 31, which is not compressed, can be distinguished by the difference in outer diameter. This makes it possible to compress the compression section 30 without compressing the non-compression section 31. Therefore, it is easy to apply a compressive force to the stranded wire 3 at the compression section 30 to connect the electric wires 2A, 2B to the sleeve 1, while causing the "Warai" phenomenon, in which the stranded wire 3 expands due to an expansion force generated against the compression force, at a position inside the non-compression section 31 and within the inner tube 5, and release the expansion force inside the sleeve 1 (inside the inner tube 5).

[0050] If the expansion force is released within the sleeve 1 as described above, it is possible to reduce the expansion force accumulated in the range of the stranded wires 3 of the electric wires 2A and 2B arranged outside the sleeve 1. Therefore, when the coating 4 is stripped off at the ends of the electric wires 2A and 2B to expose the stranded wires 3 in order to connect the electric wires 2A and 2B to another electric wire (an electric wire other than the electric wires 2A and 2B) using another sleeve 1 (a sleeve 1 different from the sleeve 1 used to connect the electric wires 2A and 2B), it is possible to suppress the "stretching" phenomenon, in which the exposed stranded wires 3 swell due to the expansion force (FIG. 10 shows a state in which the "stretching" phenomenon is suppressed in the stranded wires 3 at the end 22B when the coating 4 is stripped off at the end 22B of the electric wire 2B to expose the stranded wires 3 in order to connect the electric wire 2B to another electric wire (not shown) using another sleeve 1 (the sleeve 1 on the right of the two sleeves 1, 1 shown in FIG. 10). Therefore, the ends of the electric wires 2A, 2B can be easily inserted into the sleeve 1, and the electric wires 2A, 2B can be easily connected to other electric wires.

[0051] Furthermore, according to the above embodiment, not only the inside of the one side portion 7 of the inner tube 5 but also the inside of the other side 10B of the first protruding portion 10 is used as a space for inserting the end portion 20A of one electric wire 2A with the stranded wires 3 exposed (FIGS. 3 and 4(B)). Therefore, when the expansion force acting on the stranded wires 3 of the electric wire 2A is large, the "Warai" phenomenon, in which the stranded wires 3 expand due to the expansion force, can occur not only inside the one side portion 7 of the inner tube 5 but also inside the other side 10B of the first protruding portion 10, as shown in FIG. 11. Therefore, even when the expansion force acting on the stranded wires 3 of the electric wire 2A is large, the expansion force can be released. In addition, in order to cause the ``Warai'' phenomenon in which the twisted wire 3 expands inside the other side 10B of the first protrusion 10 as well, as described in the above embodiment, in the first intermediate portion compression process, it is preferable to compress one compressed portion 30 in the first intermediate portion 11 from the other side to one side without compressing the non-compressed portion 31 adjacent to the one compressed portion 30, but compressing one compressed portion 30 in the first intermediate portion 11 without compressing the non-compressed portion 31 adjacent to the one compressed portion 30 may also be performed from one side to the other side or randomly.

[0052] Furthermore, according to the above embodiment, not only the inside of the other side portion 8 of the inner tube 5 but also the inside of the one side 13B of the second protruding portion 13 is used as a space for inserting the end portion 20B of the other electric wire 2B with the stranded wires 3 exposed (FIGS. 3 and 5(B)). Therefore, when the expansion force acting on the stranded wires 3 of the electric wire 2B is large, the "Warai" phenomenon in which the stranded wires 3 expand due to the expansion force can be caused not only inside the other side portion 8 of the inner tube 5 but also inside the one side 13B of the second protruding portion 13, as shown in FIG. 11. Therefore, even when the expansion force acting on the stranded wires 3 of the electric wire 2B is large, the expansion force can be released. In addition, in order to cause the ``Warai'' phenomenon in which the twisted wire 3 expands inside one side 13B of the second protrusion 13 as well, as described in the above embodiment, in the second intermediate portion compression process, it is preferable to compress one compressed portion 30 in the second intermediate portion 12 from one side to the other without compressing the non-compressed portion 31 adjacent to that compressed portion 30, but compressing one compressed portion 30 in the second intermediate portion 12 without compressing the non-compressed portion 31 adjacent to that compressed portion 30 may also be performed from the other side to one side, or may be performed randomly.

[0053] Furthermore, according to the sleeve 1 of the above embodiment, the outer tube 6 covers the periphery of the inner tube 5, thereby preventing rusting of the inner tube 5. This allows the twisted wires 3, 3 of the two electric wires 2A, 2B to be stably maintained in an electrically connected state via the inner tube 5.

[0054] The present invention is not limited to the above-described embodiment, and various modifications can be made.

[0055] 12 , the interior of the one side portion 7 of the inner tube 5 may be used for inserting the end portion 20A of one electric wire 2A from which the coating 4 has been stripped to expose the stranded wires 3, the interior of the entire length of the first protruding portion 10 may be used for inserting the subsequent portion 21A of one electric wire 2A from which the coating 4 has not been stripped, the interior of the other side portion 8 of the inner tube 5 may be used for inserting the end portion 20B of the other electric wire 2B from which the coating 4 has been stripped to expose the stranded wires 3, and the interior of the entire length of the second protruding portion 13 may be used for inserting the subsequent portion 21B of the other electric wire 2B from which the coating 4 has not been stripped. In this case, in the first electric wire insertion step, the end portion 20A of one electric wire 2A from which the coating 4 has been stripped to expose the stranded wires 3 is inserted into the one side portion 7 of the inner tube 5, and the subsequent portion 21A of one electric wire 2A from which the coating 4 has not been stripped is inserted into the interior of the first protruding portion 10. Furthermore, in the second wire insertion step, the end 20B of the other electric wire 2B, from which the coating 4 has been stripped to expose the stranded wires 3, is inserted into the other side portion 8 of the inner tube 5, and the subsequent portion 21B of the other electric wire 2B, from which the coating 4 has not been stripped, is inserted throughout the entire length of the second protruding portion 13. Even when the above-mentioned change is made, by compressing each of the compressed portions 30 in the first intermediate portion 11 without compressing each of the non-compressed portions 31 in the first intermediate portion 11 in the first intermediate portion compression step, the "Warai" phenomenon, in which the stranded wires 3 of the electric wire 2A expand, can be caused at a position inside the inner tube 5 inside each non-compressed portion 31 of the first intermediate portion 11, and the expansion force can be released at that position. Furthermore, in the second intermediate section compression process, by compressing each of the compressed sections 30 in the second intermediate section 12 without compressing each of the non-compressed sections 31 in the second intermediate section 12, the "Warai" phenomenon in which the twisted wire 3 of the electric wire 2B expands can be caused at a position inside the inner tube 5 inside each non-compressed section 31 of the second intermediate section 12, and the expansion force can be released at that position.

[0056] Furthermore, in the above embodiment, the first intermediate section compressing step and the second intermediate section compressing step are performed using a pair of compression tools 40, 40 (FIGS. 4 and 5). However, the compression of the compressed section 30 in the first intermediate section compressing step and the second intermediate section compressing step can also be performed using a tool other than the compression tool 40. An example of a tool other than the compression tool 40 is the hydraulic compression tool K-500 for cable connection manufactured by Osaka Dengu Co., Ltd. Furthermore, in the above embodiment, the compressed section 30 and the non-compressed section 31 are distinguishable from each other by having different outer diameters. However, the compressed section 30 and the non-compressed section 31 may be distinguishable from each other by having different colors. Even in the above cases, one compressed section 30 can be compressed without compressing the non-compressed section 31 adjacent to that compressed section 30, so that while a compressive force is applied to the stranded wire 3 at the position of the compressed section 30, the "Warai" phenomenon, in which the stranded wire 3 expands due to an expansion force generated against the compressive force, can be generated at a position inside the inner tube 5, inside the non-compressed section 31. Therefore, the expansion force can be released inside the sleeve 1 (inside the inner tube 5). [Explanation of symbols]

[0057] 1 sleeve 2A One wire 2B The other wire 3 strands 4 Covering 5 Inner cylinder 6 outer cylinder 7 One side of the inner cylinder 8 Other side of inner cylinder 10 First protrusion 10A One side of the first protrusion 10B Other side of first protrusion 11 First intermediate part 12 Second intermediate part 13 Second protrusion 13A Other side of second protrusion 13B One side of the second protrusion 20A One end of the wire 20B End of the other wire 21A The succeeding part of one wire 21B The succeeding part of the other wire 30 Compression section 31 Uncompressed section 40 Compression tool 41 Outer width of groove 42 Groove width center 43 Groove 50 One end of the inner cylinder 51 other end of inner cylinder

Claims

1. A sleeve used to connect two electric wires, each of which includes a stranded wire formed by bundling a plurality of conductive wires together and an electrically insulating coating covering the periphery of the stranded wire, an inner cylinder formed from a conductive material; an outer cylinder formed from an electrically insulating material; The inner cylinder is disposed inside the outer cylinder, the outer cylinder has a structure in which a first protruding portion protruding to one side beyond one side end of the inner cylinder, a first intermediate portion covering the outside of one side of the inner cylinder, a second intermediate portion covering the outside of the other side of the inner cylinder, and a second protruding portion protruding to the other side beyond the other side end of the inner cylinder are connected in sequence, an inside of one side portion of the inner cylinder is used for inserting an end portion of the one electric wire from which the coating has been stripped to expose the stranded wires; At least a part of the inside of the first protrusion is used to insert a subsequent portion of the one electric wire whose coating is not stripped, the inside of the other side portion of the inner tube is used for inserting an end portion of the other electric wire from which the coating has been stripped to expose the stranded wire, At least a part of the inside of the second protrusion is used to insert a subsequent part of the other electric wire whose coating is not stripped, The first intermediate portion and the second intermediate portion are sleeves in which compressed portions that are compressed when connecting the two electric wires and non-compressed portions that have an outer diameter or outer surface color different from the compressed portions and are not compressed when connecting the two electric wires are alternately formed in the longitudinal direction.

2. The sleeve of claim 1 , wherein the non-compressed portion has an outer diameter greater than the outer diameter of the compressed portion.

3. The sleeve of claim 1 , wherein the longitudinal width of the uncompressed portion is smaller than the longitudinal width of the compressed portion.

4. the inner cylinder is formed from aluminum, an aluminum alloy, copper, or a copper alloy as the conductive material; The sleeve according to claim 1 , wherein the outer cylinder is made of a resin as the electrically insulating material.

5. A method for connecting the two electric wires using the sleeve according to claim 1, comprising: a first wire insertion step of inserting the one electric wire into the first protruding portion and into the one side portion of the inner cylinder; a first intermediate portion compressing step of radially compressing each of the compressed portions in the first intermediate portion; a second wire insertion step of inserting the other electric wire into the second protruding portion and the other side portion of the inner tube; a second intermediate portion compressing step of compressing each of the compressed portions in the second intermediate portion in a radial direction, In the first electric wire insertion step, an end portion of the one electric wire, from which the coating is stripped to expose the stranded wire, is inserted into one side portion of the inner tube, and a subsequent portion of the one electric wire, from which the coating is not stripped, is inserted into the first protruding portion, In the first intermediate portion compressing step, one compressed portion in the first intermediate portion is compressed from the other side to the one side without compressing the non-compressed portion adjacent to the one compressed portion in the first intermediate portion, so that each compressed portion in the first intermediate portion is compressed without compressing each non-compressed portion in the first intermediate portion, and one side portion of the inner tube is brought into close contact with the end of the one electric wire, and the one electric wire is connected to the sleeve, In the second electric wire insertion step, an end portion of the other electric wire, from which the coating is stripped to expose the stranded wire, is inserted into the other side portion of the inner tube, and a subsequent portion of the other electric wire, from which the coating is not stripped, is inserted into the second protruding portion, In the second intermediate portion compression process, one compressed portion in the second intermediate portion is compressed from one side to the other without compressing the non-compressed portion adjacent to the one compressed portion in the second intermediate portion, so that each of the compressed portions in the second intermediate portion is compressed without compressing each of the non-compressed portions in the second intermediate portion, so that the other side of the inner tube is in close contact with the end of the other electric wire, and the other electric wire is connected to the sleeve.

6. In the first electric wire insertion step, an end portion of the one electric wire, from which the coating is stripped to expose the stranded wire, is inserted into one side of the inner tube and the other side of the first protruding portion, and a subsequent portion of the one electric wire, from which the coating is not stripped, is inserted into the one side of the first protruding portion, 6. The electric wire connecting method according to claim 5, wherein in the second electric wire insertion step, an end of the other electric wire, from which the coating has been stripped to expose the stranded wire, is inserted into the interior of the other side portion of the inner tube and the interior of one side of the second protruding portion, and a subsequent portion of the other electric wire, from which the coating has not been stripped, is inserted into the interior of the other side of the second protruding portion.

7. the first intermediate portion compressing step and the second intermediate portion compressing step are each performed using a pair of metal compression tools; In each of the first intermediate portion and the second intermediate portion, the compressed portions and the non-compressed portions having an outer diameter larger than that of the compressed portions are alternately formed in the longitudinal direction, Each of the compression tools has a groove formed therein that is deeper on both outer sides than on the center of the width, In the first intermediate portion compressing step, compressing one compressed portion in the first intermediate portion without compressing the non-compressed portion adjacent to the one compressed portion in the first intermediate portion is achieved by pressing the pair of compression tools against the first intermediate portion with the grooves of the pair of compression tools facing each other and the first intermediate portion positioned between the pair of compression tools so that the one compressed portion of the first intermediate portion is located at the center of the width of the groove of each of the compression tools and the non-compressed portion adjacent to the one compressed portion of the first intermediate portion is located outside the width of the groove of each of the compression tools, and until the peripheral surfaces of the grooves of the pair of compression tools abut against each other, the one compressed portion of the first intermediate portion is compressed by the bottom surface at the center of the width of the groove of each of the compression tools, but the non-compressed portion adjacent to the one compressed portion of the first intermediate portion is not compressed, 6. The method for connecting electric wires according to claim 5, wherein in the second intermediate portion compression step, compressing one compressed portion in the second intermediate portion without compressing the non-compressed portion adjacent to the one compressed portion in the second intermediate portion is achieved by pressing the pair of compression tools against the second intermediate portion with the grooves of the pair of compression tools facing each other and the second intermediate portion positioned between the pair of compression tools so that the one compressed portion of the second intermediate portion is located at the center of the width of the groove of each of the compression tools and the non-compressed portion adjacent to the one compressed portion in the second intermediate portion is located outside the width of the groove of each of the compression tools, and until the peripheral surfaces of the grooves of the pair of compression tools abut against each other, the one compressed portion of the second intermediate portion is compressed by the bottom surface at the center of the width of the groove of each of the compression tools, but the non-compressed portion adjacent to the one compressed portion of the second intermediate portion is not compressed.

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