Stranded wire and method for manufacturing stranded wire

Abstract

The present invention provides a stranded wire that can significantly enhance the skin effect and improve bending characteristics and flexibility, as well as a method for manufacturing the stranded wire. [Solution] The device consists of one or more layers arranged in the same circumference and has an inner layer 6 with a hollow portion 5 inside. Outside the inner layer 6, there is a single outer layer 2 made up of multiple first strands 11 arranged in the same circumference. The first strands 11 are all the same diameter and are thinner than the strands 12 that make up the outermost layer 3 of the inner layer 6. The number of first strands 11 is 7 or more than the number of strands 12 and 13 that make up each of the layers 3 and 4 of the inner layer 6.

Description

Technical Field

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[0003]

[0001] The present invention relates to a twisted wire and a method for manufacturing the twisted wire.

Background Art

[0002] In recent years, in the wire and cable market, from the viewpoints of reducing the diameter, weight, and enhancing the functionality of wires and cables, as shown in FIG. 6, the first strand 101 is arranged circumferentially so that the cross-section becomes nearly circular and has a hollow portion inside, a first outer layer 102 is formed, inside the first outer layer 102, a second strand 103 is arranged circumferentially to form a second outer layer 104, inside the second outer layer 104, a third strand 105 is arranged circumferentially to form a third outer layer 106, and a stranded conductor 110 having a hollow portion 107 formed inside the third outer layer 106 has been proposed (Patent Document 1).

[0003] The diameter of the first strand 101 constituting the first outer layer 102 is formed larger than the diameter of the second strand 103 constituting the second outer layer 104. Further, the first strand 101 constituting the first outer layer 102 is disposed so as to be located outside the valley portion formed by the second strands 103, 103 that constitute the second outer layer 104 and are adjacent to each other in the circumferential direction.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the conventional stranded conductor 110 described above, the diameter of the first strand 101 constituting the first outer layer 102 is larger than the diameter of the second strand 103 constituting the second outer layer 104. Therefore, when a high-frequency current is applied, the current flowing through the first strand 101 constituting the first outer layer 102 increases due to the skin effect. However, because the diameter of the first strand 101 is large, the electrical resistance of the first strand 101 is large, and the overall electrical resistance of the stranded conductor 110 increases, which presents problems in terms of electrical and acoustic characteristics.

[0006] Furthermore, in the conventional stranded conductor 110 described above, the first strands 101 constituting the first outer layer 102 are arranged to be located outside the valley portion 109, which is composed of the second strands 103, 103 that constitute the second outer layer 104 and are adjacent to each other in the circumferential direction. As a result, there are problems with bending characteristics and flexibility.

[0007] Therefore, the present invention aims to provide a stranded wire that can significantly enhance the skin effect and improve bending characteristics and flexibility, as well as a method for manufacturing a stranded wire. [Means for solving the problem]

[0008] To solve the aforementioned problems, the present invention is composed of one or more layers arranged in the same circumferential direction, and has an inner layer having a hollow portion inside. An outer layer is provided on the outside of this inner layer, consisting of multiple first wires arranged in the same circular pattern. The first strand is composed of the same diameter, and is formed to be thinner than the diameter of the strands that make up the outermost layer of the inner layer. The stranded wire is characterized in that the number of first strands is 7 or more greater than the number of strands constituting each layer of the inner layer.

[0009] Furthermore, the contact points between the radial outer edge of the stranded wire in the outermost layer of the inner layer and the radial inner edge of the stranded wire in the outer layer may be located on the same circumference.

[0010] Furthermore, the outermost layer of the inner layer is formed, and on the outside of the valley portion formed by the outer surface of the adjacent strands, The first strand constituting the outer layer may be designed to prevent it from falling in.

[0011] Furthermore, the twisting direction of the strands constituting the inner layer may be different from the twisting direction of the first strands constituting the outer layer.

[0012] Furthermore, the twisting direction of the strands constituting the inner layer is the same as the twisting direction of the first strands constituting the outer layer. The twist pitch of the strands constituting the inner layer and the twist pitch of the first strands constituting the outer layer may be different.

[0013] Furthermore, it is composed of one or more layers arranged in the same circumferential pattern, and has an inner layer with a hollow section inside. An outer layer is provided on the outside of this inner layer, consisting of multiple first wires arranged in the same circular pattern. The first strand is composed of the same diameter, and is formed to be thinner than the diameter of the strands that make up the outermost layer of the inner layer. The number of the first strands is seven or more times greater than the number of strands constituting each layer of the inner layer. The method for manufacturing stranded wire is characterized by forming the inner layer by compressing it from the outside of the outermost layer, or by forming it without compression, and then forming the outer layer on the outside of the inner layer. [Effects of the Invention]

[0014] According to the invention of the present application, it is composed of one or more layers arranged in the same circumferential shape, and has an inner layer with a hollow portion inside. Outside this inner layer, one layer of outer layer is provided by arranging a plurality of first element wires in the same circumferential shape. The first element wires are formed with the same diameter and are thinner than the diameter of the element wires constituting the outermost layer of the inner layer. The number of the first element wires is 7 or more more than the number of the element wires constituting each layer of the inner layer. When a high-frequency current flows, even if the current flowing through the first element wires constituting the outer layer increases due to the skin effect, the electrical resistance flowing through the first element wires is small. Therefore, the skin effect can be made remarkable, and the bending characteristics and flexibility can be improved.

Brief Description of Drawings

[0015] [Figure 1] Cross-sectional view of the twisted wire according to Example 1 of the present invention. [Figure 2] Cross-sectional view of an example of the twisted wire according to Example 3 of the present invention. [Figure 3] Cross-sectional view of another example of the twisted wire according to Example 3 of the present invention. [Figure 4] Cross-sectional view of an example of the twisted wire according to Example 4 of the present invention. [Figure 5] Cross-sectional view of another example of the twisted wire according to Example 4 of the present invention. [Figure 6] Cross-sectional view of the twisted wire conductor of the prior art.

Modes for Carrying Out the Invention

[0016] The modes for carrying out the present invention will be described based on the drawings.

[0017] [Example 1] FIG. 1 is a cross-sectional view cut in a direction orthogonal to the axial direction of the twisted wire 1 according to Example 1 of the present invention. The oblique lines indicating the cross-sections of the respective element wires are omitted to avoid complication of the drawing.

[0018] Stranded wire 1 can be used as a stranded conductor for electric wires and cables, a catheter tube used in treatment, a guide wire that passes through blood vessels, a wire for operating endoscopes, and other medical wires.

[0019] As shown in Figure 1, the stranded wire 1 is composed of three layers: an outer layer 2 located radially to the outermost part from its center, a first inner layer 3 provided radially inward from the center of the stranded wire 1 within the outer layer 2, and a second inner layer 4 provided radially inward from the center of the stranded wire 1 within the first inner layer 3. A hollow portion 5 is formed radially inward from the center of the stranded wire 1 within the second inner layer 4. The stranded wire 1 is composed of one outer layer 2 and two inner layers 6 made up of the first inner layer 3 and the second inner layer 4.

[0020] The outer layer 2 is composed of first strands 11, the first inner layer 3 is composed of second strands 12, and the second inner layer 4 is composed of third strands 13. The stranded wire 1 is composed of three types of strands 11, 12, and 13. The twisting direction of the first strands 11 that make up the outer layer 2 and the second strands 12 that make up the first inner layer 3 are configured to be different directions. Furthermore, the twisting direction of the second strands 12 that make up the first inner layer 3 and the third strands 13 that make up the second inner layer 4 are configured to be the same.

[0021] The twist pitch of the first strand 11 constituting the outer layer 2 may be the same as, or different from, the twist pitch of the second strand 12 constituting the first inner layer 3 and the third strand 13 constituting the second inner layer 4.

[0022] The first strand 11 consists of 38 strands, while the second strand 12 and the third strand 13 each consist of 15 strands.

[0023] When stranded wire 1 is used as a stranded conductor, the base wire material for each strand 11, 12, 13 can be, for example, copper wire such as bare copper wire, oxygen-free copper wire, linear crystalline oxygen-free copper wire, single-crystal high-purity oxygen-free copper wire, copper wire plated with tin, nickel, silver, etc., aluminum wire, various alloy wires, and insulated wires such as enameled wire, Litz wire, and Formal wire.

[0024] When stranded wire 1 is used as a medical wire, the base wire material for each strand 11, 12, and 13 can be, for example, hard copper wire, alloy wire, nickel wire, stainless steel wire, titanium wire, etc.

[0025] The materials used for each strand 11, 12, and 13 may be the same or different.

[0026] As shown in Figure 1, the outer layer 2 is constructed by arranging 38 first strands 11 on the same circumference. The outer layer 2 has a circular cross-section and is composed entirely of first strands 11 of the same diameter. Adjacent first strands 11, 11 in the circumferential direction centered on the center of the stranded wire 1 are arranged to abut along their entire axial direction, or in part of their axial direction.

[0027] As shown in Figure 1, the first inner layer 3 is constructed by arranging 15 second wires 12 on the same circumference, with adjacent second wires 12 spaced apart from each other. The first inner layer 3 has a circular cross-section and is composed entirely of second wires 12 of the same diameter.

[0028] The twist direction of the first strands 11 constituting the outer layer 2 and the twist direction of the second strands 12 constituting the first inner layer 3 are configured to be in different directions. Therefore, the first strands 11 are arranged so as not to fall into the valleys 15 between adjacent second strands 12, 12 in the circumferential direction, that is, so as not to come into contact with the outer surface of the second strands 12 in the valleys 15.

[0029] As a result, the virtual circle formed by the radial inner edge of the stranded wire 1 in each first strand 11 and the virtual circle formed by the radial outer edge of the stranded wire 1 in each second strand 12 are approximately the same. That is, the contact points between the radial inner edge of the stranded wire 1 in each first strand 11 and the radial outer edge of the stranded wire 1 in the second strand 12 are located on the same circumference.

[0030] The diameter d2 of the second strand 12 is formed to be larger than the diameter d1 of the first strand 11.

[0031] As shown in Figure 1, the second inner layer 4 is constructed by arranging 15 third strands 13 on the same circumference. The second inner layer 4 has a circular cross-section and is composed of all third strands 13 of the same diameter. Adjacent third strands 13, 13 in the circumferential direction centered on the center of the stranded wire 1 are arranged to abut along their entire axial direction, or in part of their axial direction.

[0032] The third strand 13 is arranged in the inner valley portion 15, which is composed of adjacent second strands 12, 12 in the circumferential direction centered on the center of the stranded wire 1, so as to be in contact with these adjacent second strands 12, 12 in the entire axial direction or in part of the axial direction.

[0033] The diameter d3 of the third strand 13 is formed to be smaller than the diameter d2 of the second strand 12.

[0034] In this embodiment 1, we used individual wires 11, 12, and 13 such that the relationships d1 = 0.523 × d2 and d3 = 0.694 × d2 hold true.

[0035] Furthermore, the cross-sectional shape of the stranded wire 1 is formed to be approximately circular, that is, the distance L1 from the center of the stranded wire 1 to the outermost edge of each first strand 11 constituting the outer layer 2 is formed to be approximately the same. Also, the distance L2 from the center of the stranded wire 1 to the outermost edge of each second strand 12 constituting the first inner layer 3 is formed to be approximately the same, and the distance L3 from the center of the stranded wire 1 to the outermost edge of each third strand 13 constituting the second inner layer 4 is formed to be approximately the same.

[0036] Furthermore, the distance to the innermost edge of each first strand 11 constituting the outer layer 2 is formed to be approximately the same as the distance L2 to the outermost edge of each second strand 12 constituting the first inner layer 3.

[0037] Next, the manufacturing method for stranded wire 1 will be explained.

[0038] First, an inner layer 6 is formed, consisting of two layers: a first inner layer 3 and a second inner layer 4, with a hollow portion 5 in the center. Next, an outer layer 2 is formed on the outside of the inner layer 6, with a twisting direction different from that of the inner layer 6, to form a stranded wire 1.

[0039] Because the stranded wire 1 of the present invention has the above-described structure, it provides the following functions and effects.

[0040] By making the outer shape of the stranded wire 1 approximately circular without compression, each strand 11, 12, and 13 experiences minimal reduction in elongation, and its physical properties such as bending characteristics, flexibility, and pliability are not impaired, thus maintaining its physical properties. Furthermore, even when the inner diameter of the hollow section 5 is made large, the shape of the stranded wire 1 can be stably maintained.

[0041] Furthermore, even when each strand 11, 12, and 13 of the stranded wire 1 is made of stainless steel wire, titanium wire, etc., the shape of the stranded wire 1 is stabilized, unraveling is less likely to occur, and the stranded wire 1 can be maintained in a predetermined shape and arrangement.

[0042] Furthermore, by making the diameter d1 of the first strand 11 thinner than the diameter d2 of the second strand 12, and by increasing the number of first strands 11 by 7 or more than the number of second strands 12, even if a high-frequency current flows and the current flowing through the first strands 11 constituting the outer layer 2 increases due to the skin effect, the electrical resistance flowing through the first strands 11 is small. Therefore, the increase in the overall electrical resistance of the stranded wire 1 can be suppressed, the skin effect can be made more pronounced, and the adverse effects of the skin effect can be reduced compared to the conventional technology 1.

[0043] Therefore, stranded wire 1 can be obtained with high reliability and can be effectively utilized in fields such as automotive wires, acoustic wires, and medical wires.

[0044] In the above embodiment 1, the twist direction of the first strand 11 constituting the outer layer 2 and the second strand 12 constituting the first inner layer 3 are different, while the twist direction of the second strand 12 constituting the first inner layer 3 and the third strand 13 constituting the second inner layer 4 are the same. However, the twist direction of the first strand 11 constituting the outer layer 2, the second strand 12 constituting the first inner layer 3, and the third strand 13 constituting the second inner layer 4 may all be the same. In that case, the twist pitch of the first strand 11 constituting the outer layer 2 is configured to be different from the twist pitch of the second strand 12 constituting the first inner layer 3 and the third strand 13 constituting the second inner layer 4.

[0045] [Example 2] If an arrangement similar to that of the stranded wire 1 in Example 1 can be formed, the stranded wire 1 can be constructed using strands of any diameter other than those having the diameters described in Example 1, as long as the diameter d2 of the second strand 12 is greater than the diameter d1 of the first strand 11, and the diameter d3 of the third strand 13 is smaller than the diameter d2 of the second strand 12. Furthermore, the outer layer 2, which is the outermost layer in the stranded wire 1, may be compressed from the outside. The compression ratio can be set arbitrarily.

[0046] Alternatively, the inner layer 6 constituting the stranded wire 1 may be formed by compressing it from the outside of the first inner layer 3, which is the outermost layer, using a compression die or the like, and then an outer layer 2 may be added to the outside to form the stranded wire 1.

[0047] This compression causes the outer periphery of the first strand 11 constituting the outer layer 2 to be compressed and deformed, making the outer shape of the stranded wire 1 closer to a perfect circle.

[0048] The other structures are the same as in Example 1 above, so their description will be omitted.

[0049] In this embodiment 2, the same effects and advantages as in embodiment 1 can be achieved.

[0050] [Example 3] In the above embodiments 1 and 2, the stranded wire 1 was composed of 38 first strands 11 and 15 second strands 12 and 15 third strands 13. However, as long as the number of second strands 12 and third strands 13 are the same, and the number of first strands 11 is 7 or more greater than the number of second strands 12, the number of strands 11, 12, and 13 can each be set to any number.

[0051] The first strand 11, the second strand 12, and the third strand 13 are arranged in the same regularity as in the above examples 1 and 2.

[0052] Since the contact points between the radial inner edge of the stranded wire 1 in the first strand 11 and the radial outer edge of the stranded wire 1 in the second strand 12 are located on the same circumference, if the diameter of the first strand 11 is d1, the diameter of the second strand 12 is d2, the number of first strands 11 is n, and the number of second strands 12 is N, The relationship d1 = d2 × {1 / sin(180 / N) + 1} / {1 / sin(180 / n) - 1} ... (1) holds true.

[0053] For example, as shown in Figure 2, in the case of a stranded wire 21 composed of 49 first strands 11 and 20 second strands 12 and 20 third strands 13, substituting n=49 and N=20 into the above equation (1), d1=d2×{1 / sin(180 / 20)+1} / {1 / sin(180 / 49)―1}=0.506×d2 We can obtain the relationship equation.

[0054] In this way, from the number of first strands 11 n and the number of second strands 12 N, we can derive a relationship between the diameter d1 of the first strand 11 and the diameter d2 of the second strand 12.

[0055] Furthermore, by using the base wire material for each strand 11, 12, and 13 such that the relationships d1 = 0.506 × d2 and d3 = 0.760 × d2 hold, the cross-sectional shape of the stranded wire 21 can be made approximately circular with no compression or a low compression ratio.

[0056] Furthermore, as shown in Figure 3, in the case of a stranded wire 22 composed of 22 first strands 11 and 15 second strands 12 and 15 third strands 13, by using the base wire material for each strand 11, 12, and 13 such that the relationships d1 = 0.964 × d2 and d3 = 0.694 × d2 hold, the cross-sectional shape of the stranded wire 22 can be made approximately circular with no compression or a low compression ratio.

[0057] The other structures are the same as those in Examples 1 and 2 above, so their description will be omitted.

[0058] In this embodiment 3, the same effects and advantages as in embodiments 1 and 2 can be achieved.

[0059] [Example 4] In the above embodiments 1 to 3, the stranded wires 1, 21, and 22 had an inner layer 6 composed of two layers: a first inner layer 3 and a second inner layer 4. However, the inner layer may be composed of one layer or three or more layers. When the inner layer is composed of one layer, it is preferable to manufacture the stranded wire by compressing it from the outside of the first inner layer, which is located on the outermost side of the inner layer, using a compression die or the like.

[0060] The outer and inner layers of this embodiment are arranged in the same regularity as in embodiments 1 and 2 described above.

[0061] For example, as shown in Figure 4, in the case of a stranded wire 36 in which the inner layer 31 is composed of one layer of the first inner layer 33 consisting of the second strands 32, and the stranded wire 36 is composed of 38 first strands 11 and 15 second strands 32, by using the base wire material for each strand 11 and 33 such that the relationship d1 = 0.523 × d2 holds, the cross-sectional shape of the stranded wire 36 can be made approximately circular with no compression or a low compression ratio.

[0062] Furthermore, as shown in Figure 5, in the case of a stranded wire 37 in which the inner layer 31 is composed of one layer of the first inner layer 33 consisting of the second strands 32, and the stranded wire 37 is composed of 22 first strands 11 and 15 second strands 32, by using the base wire material for each strand 11 and 33 such that the relationship d1 = 0.964 × d2 holds, the cross-sectional shape of the stranded wire 37 can be made approximately circular with no compression or a low compression ratio.

[0063] The other structures are the same as those in Examples 1 to 3 above, so their description will be omitted.

[0064] In this embodiment 4, the same effects and advantages as in embodiments 1 to 3 can be achieved. [Explanation of Symbols]

[0065] 1,21,22,36,37 stranded wire 2 Outer layer 5 Hollow part 6,31 Inner layer 11. First strand

Claims

1. It consists of one or more layers arranged in the same circumferential shape, and has an inner layer with a hollow section inside. An outer layer is provided on the outside of this inner layer, consisting of multiple first wires arranged in the same circular pattern. The first strand is composed of the same diameter and is formed to be thinner than the diameter of the strands that make up the outermost layer of the inner layer. The stranded wire is characterized in that the number of the first strands is seven or more greater than the number of strands constituting each layer of the inner layer.

2. The stranded wire according to claim 1, characterized in that the contact portion between the radial outer edge of the stranded wire in the outermost layer of the inner layer and the radial inner edge of the stranded wire in the outer layer are located on the same circumference.

3. It constitutes the outermost layer of the aforementioned inner layer, and is located outside the valley portion formed by the outer surface of adjacent strands, The stranded wire according to claim 2, characterized in that the first strand constituting the outer layer does not fall in.

4. The stranded wire according to claim 1 or 2, characterized in that the direction of twisting of the strands constituting the inner layer is different from the direction of twisting of the first strands constituting the outer layer.

5. The twisting direction of the strands constituting the inner layer is the same as the twisting direction of the first strands constituting the outer layer. The stranded wire according to claim 1 or 2, characterized in that the stranding pitch of the strands constituting the inner layer and the stranding pitch of the first strands constituting the outer layer are different.

6. It consists of one or more layers arranged in the same circumferential shape, and has an inner layer with a hollow section inside. An outer layer is provided on the outside of this inner layer, consisting of multiple first wires arranged in the same circular pattern. The first strand is composed of the same diameter and is formed to be thinner than the diameter of the strands that make up the outermost layer of the inner layer. The number of the first strands is seven or more times greater than the number of strands constituting each layer of the inner layer. A method for manufacturing stranded wire, characterized in that the inner layer is formed by compressing it from the outside of the outermost layer, or without compression, and then the outer layer is formed on the outside of the inner layer.

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