Shielded electric wire

Abstract

To provide a shielded electric wire capable of increasing versatility of a conductive nonwoven fabric tape and suppressing reduction of a shield effect.SOLUTION: A shielded electric wire is formed by winding a conductive nonwoven fabric tape 20 having conductive nonwoven fabrics 21 being nonwoven fabrics with conductivity and adhesive layers 22 formed on one surface of the conductive nonwoven fabrics 21 around an electric wire 10. In the conductive nonwoven fabric tape 20, the adhesive layers 22 are partially formed on the conductive nonwoven fabrics 21, and in the case where the conductive nonwoven fabric tape 20 is spirally wound to the electric wire 10, the adhesive layers 22 adhere to the electric wire 10 and also adhere to the conductive nonwoven fabric tape 20 overlapped when spirally wound, and an area ratio of the adhesive layers 22 to the conductive nonwoven fabric tape 20 and a ratio of a conductive part other than the adhesive layers 22 in lap parts La, where the conductive nonwoven fabric tapes 20 lap, to the conductive nonwoven fabric tape 20 satisfy a predetermined relation.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a shielded wire. [Background technology]

[0002] Conventionally, a shielded electric wire has been proposed in which a conductive nonwoven fabric having a nonwoven fabric and a metal layer formed on the surface of the nonwoven fabric is arranged around the outer periphery of an electric wire (see, for example, Patent Document 1). This shielded electric wire exhibits an electromagnetic shielding effect due to the metal layer of the conductive nonwoven fabric, while the nonwoven fabric has relatively excellent stretching and compressing properties due to the characteristics of the material, and can follow the bending of the electric wire. Such a conductive nonwoven fabric is made into a conductive nonwoven fabric tape by providing an adhesive layer on one surface (see, for example, Patent Documents 2 and 3), and can be attached around the electric wire using the adhesive layer. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-75375 A [Patent Document 2] JP 2021-140950 A [Patent Document 3] Patent Publication No. 2021-103775 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when the conductive nonwoven tape described in Patent Documents 2 and 3 is attached vertically around an electric wire, the lapped portion of the conductive nonwoven tape may open when the wire is bent, reducing the shielding effect. Also, when the conductive nonwoven tape is wound in a spiral shape, the lapped portion also becomes spiral and is less likely to open when the wire is bent, but since an adhesive layer is interposed between the upper and lower conductive nonwoven fabrics in the lapped portion, the conductive path also becomes spiral, resulting in a significant reduction in the shielding effect.

[0005] In response to such problems, the present applicant has made an invention relating to Japanese Patent Application No. 2022-191625. In this invention, a conductive nonwoven fabric tape is wound in a spiral shape on an electric wire. The conductive nonwoven fabric tape has an adhesive layer provided only on one end of the conductive nonwoven fabric, for example. The conductive nonwoven fabric tape is wound in a spiral shape so that the adhesive layer is not interposed between the lapped portions of the conductive nonwoven fabric when wound in a spiral shape. As a result, the spirally wound conductive nonwoven fabrics form a conductive path along the longitudinal direction of the electric wire through the lapped portion, thereby suppressing a significant decrease in the shielding effect.

[0006] However, the conductive nonwoven fabric tape requires the formation of an adhesive layer with a width that matches the width of the wrap portion, which means that the adhesive layer is formed for each wrapping state and each target electric wire (electric wire diameter, etc.), resulting in low versatility (each product is unique, etc.) Furthermore, when the conductive nonwoven fabric tape has an adhesive layer formed only on one end in the width direction of the conductive nonwoven fabric, if it is used vertically, the conductive nonwoven fabric will float away from the electric wire, reducing the shielding effect.

[0007] The present invention has been made to solve these conventional problems, and its object is to provide a shielded wire that can increase the versatility of conductive nonwoven fabric tapes and suppress a decrease in their shielding effect. [Means for solving the problem]

[0008] A shielded electric wire according to the present invention is a shielded electric wire in which a conductive nonwoven fabric tape having a conductive nonwoven fabric, which is a nonwoven fabric having electrical conductivity, and an adhesive layer formed on one surface of the conductive nonwoven fabric is wound around an electric wire, the conductive nonwoven fabric tape having the adhesive layer partially formed on the conductive nonwoven fabric, the adhesive layer being adhered to the electric wire when the conductive nonwoven fabric tape is wound spirally around the electric wire, and also adheres to the conductive nonwoven fabric tape that overlaps when wound spirally, and when the width of the spirally wound conductive nonwoven fabric tape is t, the length of the conductive nonwoven fabric tape is L, the area of ​​the adhesive layer in the conductive nonwoven fabric tape is S, the area of ​​the lap portion where the conductive nonwoven fabric tapes lap each other when the conductive nonwoven fabric tape is wound spirally is S1, and the area of ​​the adhesive layer in the lap portion is S2,

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[0009] According to the present invention, it is possible to provide a shielded wire that can increase the versatility of a conductive nonwoven fabric tape and suppress a decrease in the shielding effect. [Brief description of the drawings]

[0010] [Figure 1] 1 is a perspective view showing a shielded wire according to an embodiment of the present invention. [Diagram 2] 2A and 2B are diagrams showing the configuration of the conductive nonwoven fabric tape shown in FIG. 1, in which (a) shows a plan view on the side on which the adhesive layer is formed, (b) shows a cross section perpendicular to the longitudinal direction of the tape, and (c) shows an enlarged view of a portion of (b). [Diagram 3] 2 is a cross-sectional view taken along the longitudinal direction of the shielded electric wire shown in FIG. 1. [Figure 4]1A and 1B are conceptual diagrams showing how a magnetic field is generated, in which FIG. 1A shows the magnetic field of a reference example, and FIG. 1B shows the magnetic field of this embodiment. [Diagram 5] 1 is a table showing Examples 1 to 3 and Comparative Examples 1 to 4. [Figure 6] 13 is a graph showing the shielding effect of the shielded wires according to Example 2 and Comparative Examples 1 and 2. [Figure 7] 1 is a diagram showing a shielded electric wire when a conductive nonwoven fabric or a conductive nonwoven fabric tape is attached vertically. [Figure 8] 1 is a graph showing the shielding effect of the shielded wire according to vertical attachment examples 1, 3, and 5. [Figure 9] 10A to 10C are plan views showing conductive nonwoven fabric tapes according to modified examples, where (a) shows a first example, (b) shows a second example, and (c) shows a third example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The present invention will be described below along with preferred embodiments. Note that the present invention is not limited to the embodiments shown below, and can be modified as appropriate within the scope of the present invention. In addition, in the embodiments shown below, some configurations are omitted from illustration and description, but it goes without saying that publicly known or well-known technologies are appropriately applied to the details of the omitted technologies within the scope of the contents described below.

[0012] Fig. 1 is a perspective view showing a shielded electric wire 1 according to an embodiment of the present invention. As shown in Fig. 1, the shielded electric wire 1 according to the present embodiment is configured to include an electric wire 10 and a conductive nonwoven fabric tape 20 wound in a spiral shape around the electric wire 10. In the example shown in Fig. 1, the shielded electric wire 1 has the conductive nonwoven fabric tape 20 wound in a spiral shape, but the shape is not limited to a spiral shape, and the conductive nonwoven fabric tape 20 may be attached vertically. Also, although there is one electric wire 10 in Fig. 1, the number is not limited to one, and two or more electric wires may be used.

[0013] The electric wire 10 includes a conductor 11 made of, for example, copper, aluminum, or an alloy thereof, and an insulating coating 12 that coats the conductor 11. In the example shown in Fig. 1, the conductor 11 of the electric wire 10 is a twisted wire in which a plurality of wires are twisted together, but the present invention is not limited to this and may be a single wire. Furthermore, the coating 12 is assumed to be made of PVC (Polyvinyl Chloride), PP (Polypropylene), or PE (Polyethylene), but the present invention is not limited to this and may be made of silicone, polyurethane, nylon, or the like.

[0014] Fig. 2 is a configuration diagram showing the conductive nonwoven fabric tape 20 shown in Fig. 1, where (a) shows a plan view of the side on which the adhesive layer is formed, (b) shows a cross section perpendicular to the tape longitudinal direction, and (c) shows an enlarged view of a portion of (b). As shown in Fig. 2(a) and Fig. 2(b), the conductive nonwoven fabric tape 20 comprises a conductive nonwoven fabric 21 and an adhesive layer 22 provided on one surface (front or back) of the conductive nonwoven fabric 21.

[0015] As shown in Fig. 2(c), the conductive nonwoven fabric 21 is configured to include fibers 21a constituting the nonwoven fabric and plated portions 21b. The nonwoven fabric is a sheet-like member in which the fibers 21a are intertwined without being woven. As shown in Fig. 2(c), due to the nature of the manufacturing process, the fibers 21a of this nonwoven fabric are formed as multiple layers in the thickness direction. The fibers 21a constituting such a nonwoven fabric are made of, for example, polyethylene terephthalate (PET), PP, nylon, acrylic, glass fiber, carbon fiber, aramid fiber, polyarylate fiber, and the like.

[0016] The plated portion 21b is a conductive metal that coats the fibers 21a that constitute the nonwoven fabric. The plated portion 21b is made of, for example, copper, nickel, tin, silver, or an alloy of these metals. The plated portion 21b may be formed in a single layer on the fibers 21a that constitute the nonwoven fabric, or may be formed in multiple layers. For this reason, the plated portion 21b may be formed, for example, with copper (first layer) and tin (second layer) on the fibers 21a that constitute the nonwoven fabric.

[0017] Further, as shown in FIG. 2(a) and FIG. 2(b), the adhesive layer 22 is partially formed on one surface of the conductive nonwoven fabric 21. In the example shown in FIG. 2(a) and FIG. 2(b), the conductive nonwoven fabric tape 20 has two adhesive layers 22 formed along the longitudinal direction of the conductive nonwoven fabric tape 20. When the conductive nonwoven fabric tape 20 is divided into two equal parts in the width direction, each adhesive layer 22 is provided on one end side of each divided area. The first adhesive layer 22a of the adhesive layer 22 is formed at one end of the conductive nonwoven fabric 21 and extends in the longitudinal direction with a predetermined width. The second adhesive layer 22b is formed at a position slightly closer to the center of the conductive nonwoven fabric 21 and toward the other end and extends in the longitudinal direction with a predetermined width. In this manner, the adhesive layer 22 is formed in a linear shape with a plurality of layers continuously formed at least in the longitudinal direction.

[0018] 3 is a cross-sectional view along the longitudinal direction of the shielded electric wire 1 shown in FIG. 1. As shown in FIG. 3, when the conductive nonwoven fabric tape 20 is wound around the electric wire 10 in a spiral shape, the adhesive layer 22 adheres to the electric wire 10 and also adheres to the conductive nonwoven fabric tape 20 that is wound in a spiral shape and overlaps the electric wire 10. That is, in the case of the conductive nonwoven fabric tape 20 shown in FIG. 2, the first adhesive layer 22a adheres to the electric wire 10 when the conductive nonwoven fabric tape 20 is wound. In addition, the second adhesive layer 22b adheres to the overlapping conductive nonwoven fabric tape 20 in the lap portion La where the conductive nonwoven fabric tapes 20 overlap each other. Furthermore, the second adhesive layer 22b is provided in a part of the lap portion La, and is not provided in the remaining portion. Therefore, in the conductive nonwoven fabric tape 20 shown in FIG. 2, the conductive nonwoven fabrics 21 come into contact with each other and are conductive in the conductive portion 23 where the adhesive layer 22 is not formed.

[0019] The shielded wire 1 according to this embodiment has improved shielding performance compared to the reference example in which the adhesive layer 22 is provided over the entire conductive nonwoven fabric 21.

[0020] 4A and 4B are conceptual diagrams showing the generation of a magnetic field, where (a) shows the magnetic field in a reference example, and (b) shows the magnetic field in this embodiment. First, as shown in Fig. 4A and Fig. 4B, a current flows in the electric wire 10 in the direction in which the conductor 11 extends. Therefore, a magnetic field MF1 (see the dashed line) is generated in a direction perpendicular to the current.

[0021] Here, in the reference example shown in FIG. 4(a), the adhesive layer 22 is provided over the entire conductive nonwoven fabric 21. Therefore, in the lap portion La where the conductive nonwoven fabric tape overlaps, the adhesive layer 22 is interposed between the conductive nonwoven fabric 21. Therefore, the conductive nonwoven fabric tape shown in the reference example forms a spiral conductive path CP. In this case, on the conductive nonwoven fabric tape side, a magnetic field MF2 (see solid line) is generated in a direction perpendicular to the spiral direction. This magnetic field MF2 cannot cancel out the magnetic field MF1 generated by the current flowing through the conductor 11.

[0022] On the other hand, in the conductive nonwoven fabric tape 20 according to this embodiment, the conductive nonwoven fabrics 21 are electrically connected to each other via the conductive portion 23 in the wrap portion La as described with reference to Fig. 3. Therefore, as shown in Fig. 4(b) , the conductive nonwoven fabric tape 20 forms a conductive path CP along the longitudinal direction of the electric wire 10. Therefore, the shielded electric wire 1 according to this embodiment can generate a magnetic field MF2 (see solid line) that cancels out the magnetic field MF1 (see dashed line) generated by the current flowing through the conductor 11.

[0023] In particular, in the shielded wire 1 according to this embodiment, the proportions of the adhesive layer 22 and the conductive portion 23 are optimized, and the magnetic field MF2 that offsets the magnetic field MF1 is appropriately generated, thereby enabling the shielding effect to be optimally exhibited.

[0024] More specifically, in the shielded wire 1 according to this embodiment, when the width of the conductive nonwoven fabric tape 20 is t (see FIGS. 2(a) and 2(b)), the length of the conductive nonwoven fabric tape 20 is L (see FIG. 2(a)), and the area of ​​the adhesive layer 22 of the conductive nonwoven fabric tape 20 is S,

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[0025] Furthermore, in the shielded electric wire 1 according to this embodiment, when the area of ​​the lap portion La where the conductive nonwoven fabric tapes 20 overlap each other when the conductive nonwoven fabric tape 20 is spirally wrapped around the electric wire 10 is S1, and the area of ​​the adhesive layer 22 in the lap portion La is S2,

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[0026] The conductive nonwoven fabric tape 20 according to this embodiment satisfies the above formulas (1) and (2), and thus can form a conductive path CP extending in the longitudinal direction of the electric wire 10, as shown in Fig. 4(b). Moreover, the ratio between the adhesive layer 22 and the conductive portion 23 is also optimized, so that the conductive nonwoven fabric tape 20 can be suitably attached to the electric wire 10, and the magnetic field MF1 generated by the current flowing through the conductor 11 can be easily offset by the magnetic field MF2 due to the conductive path CP.

[0027] Here, in the example shown in FIG. 3, the conductive nonwoven fabric tape 20 is half-wrapped. However, the shielded electric wire 1 according to this embodiment is not limited to half-wrapped, and is not limited to half-wrapped as long as it satisfies formulas (1) and (2). In particular, the shielded electric wire 1 according to this embodiment may use any conductive nonwoven fabric tape 20 as long as it satisfies formulas (1) and (2). Therefore, the conductive nonwoven fabric tape 20 is unlikely to be one-of-a-kind, as shown in Patent Application No. 2022-191625, and its versatility is enhanced.

[0028] The conductive nonwoven fabric tape 20 used for the above-mentioned spiral winding is formed by appropriately forming the adhesive layer 22 on the conductive nonwoven fabric 21 having a width exceeding t, and then cutting the conductive nonwoven fabric 21 along the longitudinal direction to have a width of t. When the conductive nonwoven fabric tape 20 is used for vertical attachment, the conductive nonwoven fabric tape 20 may be used as a product without being cut while still having a width exceeding t. The manufacturing method of the conductive nonwoven fabric tape 20 is not limited to this, and for example, the conductive nonwoven fabric tape 20 used for spiral winding may be formed with the adhesive layer 22 after the conductive nonwoven fabric 21 is cut in advance to have a width of t.

[0029] Next, examples and comparative examples will be described. Fig. 5 is a table showing examples 1 to 3 and comparative examples 1 to 4.

[0030] As shown in FIG. 5, first, in the shielded electric wire shown in Example 1, the conductive nonwoven fabric tape has two adhesive layers extending along the longitudinal direction. As in the case shown in FIG. 2, one of the two adhesive layers is provided at one end of the conductive nonwoven fabric tape in the width direction, and the other is provided slightly toward the other end of the width direction center of the conductive nonwoven fabric tape. Furthermore, in Example 1, the conductive nonwoven fabric tape has a conduction ratio shown in formula (2) of 35% and an adhesive ratio shown in formula (1) of 30%. The wrap width (width of the wrap portion) is 1 / 2 from one end of the conductive nonwoven fabric tape (the area of ​​the wrap portion is 1 / 2 of the entire area). The shield resistance of such a spirally wound conductive nonwoven fabric tape was 2.27 [Ω / m].

[0031] In the shielded wire shown in Example 2, the conductive nonwoven fabric tape is the same as that in Example 1, but the width of the adhesive layer is made larger. The conduction ratio shown in formula (2) is 25%, and the adhesive ratio shown in formula (1) is 50%. The wrap width is 1 / 2 from one end of the conductive nonwoven fabric tape. The shield resistance of such a spirally wrapped conductive nonwoven fabric tape was 2.29 [Ω / m].

[0032] In the shielded wire shown in Example 3, the conductive nonwoven fabric tape is the same as that in Example 2, and the conduction ratio shown in formula (2) is 25%, and the adhesive ratio shown in formula (1) is 50%. However, one adhesive layer is formed in the center of one end side (half of one end side in the width direction), and the other adhesive layer is formed in the center of the other end side (half of the other end side in the width direction). The shield resistance of such a spirally wound conductive nonwoven fabric tape was 2.61 [Ω / m].

[0033] In the shielded wire shown in Comparative Example 1, the conductive nonwoven fabric (not a conductive nonwoven fabric tape without an adhesive layer) does not have an adhesive layer. Therefore, in the conductive nonwoven fabric in Comparative Example 1, the conduction ratio shown in formula (2) is 50%, and the adhesive ratio shown in formula (1) is 0%. The wrap width is 1 / 2 from one end. The shield resistance of such a spirally wrapped conductive nonwoven fabric was 1.52 [Ω / m].

[0034] In the shielded wire shown in Comparative Example 2, the conductive nonwoven fabric tape is the same as that in Example 2, but the adhesive layer width is made larger. Therefore, in Comparative Example 2, the conduction ratio shown in formula (2) is 15%, and the adhesive ratio shown in formula (1) is 70%. The wrap width is 1 / 2 from one end. The shield resistance of such a spirally wrapped conductive nonwoven fabric tape was 4.3 [Ω / m].

[0035] In the shielded wire shown in Comparative Example 3, the conductive nonwoven fabric (no adhesive layer, not a conductive nonwoven fabric tape) is the same as that in Comparative Example 1 (no adhesive layer). In Comparative Example 3, the conductive nonwoven fabric has a conduction ratio shown in formula (2) of 25% and an adhesive ratio shown in formula (1) of 0%. In Comparative Example 3, the wrap width is 1 / 4 from one end. The shield resistance of such a spirally wrapped conductive nonwoven fabric was 1.48 [Ω / m].

[0036] In the shielded wire shown in Comparative Example 4, the conductive nonwoven fabric tape has four adhesive layers extending along the longitudinal direction. When the conductive nonwoven fabric tape is divided into four equal parts in the width direction, each of the four adhesive layers is provided at one end of each divided area. Furthermore, in Comparative Example 4, the conductive nonwoven fabric tape has a conduction ratio shown in formula (2) of 13% and an adhesive ratio shown in formula (1) of 50%. The wrap width is 1 / 4 from one end. The shield resistance of such a spirally wound conductive nonwoven fabric tape was 4.34 [Ω / m].

[0037] In the above, an 8d coaxial wire was used as the electric wire provided inside the conductive nonwoven tape. The adhesive layer was formed from a double-sided tape (product number #8080) manufactured by DIC Corporation. The width of the conductive nonwoven tape was 20 mm. The earth part was attached by wrapping a connector around it and tightening a tie band over the conductive nonwoven tape. The tightening force of the tie band was within the range of 165 to 220 N.

[0038] Fig. 6 is a graph showing the shielding effects of the shielded wires according to Example 2 and Comparative Examples 1 and 2. In Fig. 6, the shielding effects of Examples 1 and 3 are omitted from the illustration because they are similar to Example 2. Similarly, the shielding effect of Comparative Example 3 is similar to Comparative Example 1, and the shielding effect of Comparative Example 4 is similar to Comparative Example 2, so they are omitted from the illustration.

[0039] As shown in Fig. 6, the shielded wire according to Comparative Example 1 has the best shielding effect. This is because the conductive nonwoven fabric does not have an adhesive layer, and therefore a conductive path extending in the longitudinal direction can be suitably formed. However, since the shielded wire according to Comparative Example 1 uses a conductive nonwoven fabric without an adhesive layer, the lapped portion opens when the wire is bent, and the good shielding effect as shown in Fig. 6 cannot be obtained. In addition, when a conductive nonwoven fabric without an adhesive layer is used, the position of the conductive nonwoven fabric becomes unstable, and there is a possibility that a good shielding effect cannot be obtained after long-term use, etc.

[0040] On the other hand, the shielded wire according to Example 2 has the second best shielding effect after the shielded wire according to Comparative Example 1. This is because the shielded wire according to Example 2 satisfies the conditions of formulas (1) and (2), and therefore the shield resistance is within the range of 1.5 [Ω / m] or more and 4.0 [Ω / m] or less, and a conductive path extending in the longitudinal direction can be formed relatively well. Moreover, the adhesive layer adheres to the wire and also adheres to the conductive nonwoven tape. This suppresses the possibility that the lap portion opens or the position of the conductive nonwoven tape shifts when bending, and makes it easier to obtain a relatively good shielding effect even when bending or after long-term use.

[0041] Moreover, the shielded wire according to Comparative Example 2 has the lowest shielding effect. The shielded wire according to Comparative Example 2 does not satisfy both the conditions of formula (1) and formula (2), and the shielding resistance exceeds 4.0 [Ω / m]. Therefore, even if a conductive path extending in the longitudinal direction can be formed, it is not enough to cancel out the magnetic field, and it is difficult to say that a good shielding effect is obtained.

[0042] FIG. 7 is a diagram showing a shielded electric wire when a conductive nonwoven fabric or a conductive nonwoven fabric tape is attached vertically.

[0043] First, as shown in Fig. 7, the shielded wire according to the vertically attached example 1 uses a conductive nonwoven fabric without an adhesive layer as a shielding layer. Therefore, the adhesive ratio shown in the formula (1) is 0%. The shield resistance of such a vertically attached conductive nonwoven fabric was 0.51 [Ω / m].

[0044] In addition, in the shielded electric wire according to Vertical Attachment Example 2, the conductive nonwoven fabric tape has three adhesive layers extending along the longitudinal direction. When the conductive nonwoven fabric tape is divided into three equal parts in the width direction, each of the three adhesive layers is provided on one end side of each divided area. Furthermore, in Vertical Attachment Example 1, the conductive nonwoven fabric tape has an adhesive ratio shown in formula (1) of 30%. The shield resistance of such a vertically attached conductive nonwoven fabric tape was 0.38 [Ω / m].

[0045] In addition, in the shielded wire according to the vertical attachment example 3, the conductive nonwoven fabric tape is the same as that in the vertical attachment example 2, but the width of the adhesive layer is made larger, and the adhesive ratio shown in the formula (1) is set to 50%. The shield resistance of such a vertically attached conductive nonwoven fabric tape was 0.46 [Ω / m].

[0046] In addition, in the shielded wire according to Vertical Attachment Example 4, the conductive nonwoven fabric tape has one adhesive layer extending along the longitudinal direction. The one adhesive layer is formed from one end of the conductive nonwoven fabric tape toward the other end. In Vertical Attachment Example 4, the conductive nonwoven fabric tape has an adhesive ratio shown in formula (1) of 50%, and the shield resistance of the vertically attached conductive nonwoven fabric tape is 0.52 [Ω / m].

[0047] In addition, in the shielded wire according to Vertical Attachment Example 5, the conductive nonwoven fabric tape is the same as that in Vertical Attachment Example 3, but the adhesive layer width is made larger, and the adhesive ratio shown in formula (1) is set to 70%. The shield resistance of such a vertically attached conductive nonwoven fabric tape was 1.15 [Ω / m].

[0048] Fig. 8 is a graph showing the shielding effect of the shielded wire according to vertical attachment examples 1, 3, and 5. In Fig. 8, the shielding effect of vertical attachment examples 2 and 4 is the same as that of vertical attachment example 2, and therefore is not shown.

[0049] As shown in Fig. 8, the shielded electric wire according to Vertical Attachment Example 1 has the best shielding effect. In contrast, the shielded electric wire according to Vertical Attachment Example 3 also has a shielding effect as good as that of the shielded electric wire according to Vertical Attachment Example 1. The shielded electric wire according to Vertical Attachment Example 5 has a lower shielding effect than the shielded electric wires according to Vertical Attachment Examples 1 and 3.

[0050] Here, it is clear that the conductive nonwoven fabric tapes shown in Vertical Attachment Examples 2 to 4 among Vertical Attachment Examples 1 to 5 satisfy formula (1). In addition, the conductive nonwoven fabric tapes of Vertical Attachment Examples 2 to 4 can satisfy formula (2) depending on the wrap ratio of the spiral winding (formula (2) can be satisfied depending on how the wrap portion is handled). With such conductive nonwoven fabric tapes shown in Vertical Attachment Examples 2 to 4, even when attached vertically, it was found that they provide the same shielding effect as the conductive nonwoven fabric of Vertical Attachment Example 1, and are also excellent in versatility.

[0051] In this way, according to the shielded electric wire 1 according to the present embodiment, the adhesive layer 22 adheres to the electric wire 10 and also adheres to the conductive nonwoven fabric tape 20 that is spirally wound and overlapped. Therefore, the conductive nonwoven fabric tape 20 adheres to the electric wire 10 to prevent misalignment, and also adheres to the conductive nonwoven fabric tape 20 to maintain the wound state. Moreover, the shielded electric wire 1 satisfies formula (1) when the width of the conductive nonwoven fabric tape 20 is t, the length of the conductive nonwoven fabric tape 20 is L, and the area of ​​the adhesive layer 22 in the conductive nonwoven fabric tape 20 is S. Therefore, the proportion of the adhesive layer 22 in the conductive nonwoven fabric tape 20 can be optimized. Furthermore, when the area of ​​the wrap portion La is S1 and the area of ​​the adhesive layer 22 in the wrap portion La is S2, the shielded electric wire 1 satisfies formula (2). As a result, the area (S1-S2) in which conduction is ensured by the conductive portion 23 in the wrap portion La is optimized, and the conductive path CP in the longitudinal direction is ensured even if the conductive nonwoven fabric tape 20 is spirally wound. In particular, the conductive nonwoven fabric tape 20 is not limited to one in which the adhesive layer 22 is formed only on one end, and as long as it satisfies formulas (1) and (2), it is not particularly limited in shape, is unlikely to be one-of-a-kind, and some products can be used by attaching them vertically. Therefore, it is possible to provide a shielded electric wire 1 that can increase the versatility of the conductive nonwoven fabric tape 20 and suppress a decrease in the shielding effect.

[0052] Moreover, the conductive nonwoven fabric tape 20 has a plurality of adhesive layers 22 formed continuously and linearly at least in the longitudinal direction. Therefore, it is easy to form the adhesive layer 22 on the conductive nonwoven fabric 21, and it is possible to provide a shielded electric wire 1 that can be appropriately wrapped around an electric wire in a state where the conductive nonwoven fabric tape 20 is not easily peeled off even when the conductive nonwoven fabric tape 20 is attached vertically.

[0053] The present invention has been described above based on an embodiment, but the present invention is not limited to the above embodiment, and modifications may be made without departing from the spirit of the present invention, and if possible, known or well-known technologies may be combined.

[0054] 9A and 9B are plan views showing conductive nonwoven fabric tapes according to modified examples, where (a) shows a first example, (b) shows a second example, and (c) shows a third example. As shown in Fig. 9A, the conductive nonwoven fabric tape 20a is not limited to a case in which a plurality of adhesive layers 22 extend along the longitudinal direction, but may be configured to have at least an element extending in the longitudinal direction, for example, extending in an oblique direction. This also makes it easy to form the adhesive layer 22 on the conductive nonwoven fabric 21, for example, by forming the adhesive layer 22 with a double-sided tape, and also makes it possible to appropriately wrap the conductive nonwoven fabric tape 20 around the electric wire 10 in a state in which it is difficult to peel off even when the conductive nonwoven fabric tape 20 is attached vertically.

[0055] 9(b), the conductive nonwoven fabric tape 20b may have adhesive layers 22 formed intermittently and at equal intervals in the longitudinal direction. Here, the equal intervals are not limited to adhesive layers 22 spaced apart in the longitudinal direction arranged at a constant interval. For example, the equal intervals include a case where the first and second adhesive layers 22 spaced apart in the longitudinal direction are arranged at a first interval, and the second and third adhesive layers 22 spaced apart in the longitudinal direction are arranged at a second interval, and this is repeated. This is because, even if the adhesive layers 22 are formed intermittently in this way, the same effect can be obtained by satisfying formulas (1) and (2).

[0056] Furthermore, as shown in Fig. 9(c), the conductive nonwoven fabric tape 20c may have conductive parts 23 formed intermittently and at equal intervals in the longitudinal direction. Here, "at equal intervals" is the same as that shown in Fig. 9(b). This is because even if the conductive parts 23 are formed intermittently, the same effect can be obtained as long as formulas (1) and (2) are satisfied. [Explanation of symbols]

[0057] 1: Shielded wire 10: Electric wire 20, 20a to 20c: Conductive nonwoven tape 21: Conductive nonwoven fabric 22: Adhesive layer 23: Conductive part La: Lap section

Claims

1. A shielded electric wire in which a conductive nonwoven fabric tape is wound around an electric wire, the conductive nonwoven fabric tape having a conductive nonwoven fabric and an adhesive layer formed on one surface of the conductive nonwoven fabric, The conductive nonwoven fabric tape has an adhesive layer partially formed on the conductive nonwoven fabric, When the conductive nonwoven fabric tape is wound spirally around the electric wire, the adhesive layer adheres to the electric wire and also adheres to the conductive nonwoven fabric tape that overlaps with the conductive nonwoven fabric tape when wound spirally; When the width of the conductive nonwoven fabric tape wound in a spiral shape is t, the length of the conductive nonwoven fabric tape is L, the area of ​​the adhesive layer in the conductive nonwoven fabric tape is S, the area of ​​the lap portion where the conductive nonwoven fabric tapes overlap each other when the conductive nonwoven fabric tape is wound in a spiral shape is S1, and the area of ​​the adhesive layer in the lap portion is S2, [0010] [0025] Fulfill Shielded electric wire characterized by:

2. The conductive nonwoven fabric tape has a plurality of the adhesive layers formed continuously and linearly at least in the longitudinal direction.

2. The shielded wire according to claim 1 .

3. The conductive nonwoven fabric tape has conductive portions, which are the adhesive layer or portions where the adhesive layer is not formed, formed intermittently and at equal intervals in the longitudinal direction.

2. The shielded wire according to claim 1 .

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