Shielded 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 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 stretchability and compressibility due to the characteristics of the material, so it can follow the bending of the electric wire. Such conductive nonwoven fabric is provided with an adhesive layer on one surface to form a conductive nonwoven fabric tape (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] Japanese Patent Application Publication No. 2019-75375 [Patent Document 2] Patent Publication No. 2021-140950 [Patent Document 3] Patent Publication No. 2021-103775 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when conductive nonwoven fabric tape is attached longitudinally around an electric wire as described in Patent Documents 2 and 3, the lapped portion of the conductive nonwoven fabric tape may open when the wire is bent, reducing the shielding effect. Furthermore, when the conductive nonwoven fabric tape is wrapped spirally, the lapped portion also becomes spiral-shaped, making it less likely to open when the wire is bent. However, because an adhesive layer is interposed between the upper and lower conductive nonwoven fabrics in the lapped portion, the conductive path also becomes spiral-shaped, resulting in a significant reduction in the shielding effect.

[0005] To address these issues, the present applicant has proposed an invention in accordance with Japanese Patent Application No. 2022-191625. In this invention, a conductive nonwoven fabric tape is wound spirally around an electric wire. In the conductive nonwoven fabric tape, for example, an adhesive layer is provided on only one end of the conductive nonwoven fabric. When the conductive nonwoven fabric tape is wound spirally, the adhesive layer is not interposed between the lapped portions of the conductive nonwoven fabric. As a result, the spirally wound conductive nonwoven fabrics form a conductive path along the longitudinal direction of the electric wire through the lapped portions, thereby preventing a significant decrease in shielding effect.

[0006] However, the above-mentioned 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 target electric wire (electric wire diameter, etc.), resulting in low versatility (each product is unique, etc.) Furthermore, when the above-mentioned 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 in a vertical position, 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 electric wire that can increase the versatility of conductive nonwoven fabric tapes and suppress a decrease in shielding effectiveness. [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 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, wherein the adhesive layer of the conductive nonwoven fabric tape is partially formed on the conductive nonwoven fabric, and when the conductive nonwoven fabric tape is spirally wound around the electric wire, the adhesive layer adheres to the electric wire and also adheres to the conductive nonwoven fabric tape that overlaps when spirally wound, 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 overlap each other when the conductive nonwoven fabric tape is spirally wound 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 explanation of the drawings]

[0010] [Figure 1] 1 is a perspective view showing a shielded electric wire according to an embodiment of the present invention. [Figure 2] 2A and 2B are diagrams showing the configuration of the conductive nonwoven fabric tape shown in FIG. 1, in which (a) shows a plane on the side where 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). [Figure 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 the state of magnetic field generation, in which (a) shows the state of the magnetic field in a reference example, and (b) shows the state of the magnetic field in this embodiment. [Figure 5] 1 is a table showing Examples 1 to 3 and Comparative Examples 1 to 4. [Figure 6] 10 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] 10 is a graph showing the shielding effect of the shielded wires 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 INVENTION

[0011] The present invention will be described below in accordance with preferred embodiments. Note that the present invention is not limited to the embodiments shown below and can be modified as appropriate without departing from the spirit of the present invention. In addition, in the embodiments shown below, some components are omitted from illustration and description, but it goes without saying that publicly known or well-known technologies are applied as appropriate to the details of the omitted technologies within the scope of the content 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 this embodiment is configured to include an electric wire 10 and a conductive nonwoven fabric tape 20 wound spirally around the electric wire 10. In the example shown in Fig. 1, the conductive nonwoven fabric tape 20 is wound spirally around the shielded electric wire 1, but it 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 may be two or more.

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

[0014] Fig. 2 is a structural diagram showing the conductive nonwoven fabric tape 20 shown in Fig. 1, where (a) shows a plan view on the side where 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). 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 with 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. Due to the manufacturing characteristics of this nonwoven fabric, as shown in FIG. 2(c), the fibers 21a 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, etc.

[0016] The plated portion 21b is a conductive metal that coats the fibers 21a that make up the nonwoven fabric. This 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 as a single layer on the fibers 21a that make up the nonwoven fabric, or may be formed as multiple layers. Therefore, the plated portion 21b may be formed, for example, with copper (first layer) and tin (second layer) on the fibers 21a that make up the nonwoven fabric.

[0017] 2(a) and 2(b), the adhesive layer 22 is partially formed on one surface of the conductive nonwoven fabric 21. In the example shown in FIGS. 2(a) and 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. Of the adhesive layers 22, the first adhesive layer 22a 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 slightly closer to the center of the conductive nonwoven fabric 21 to the other end and extends in the longitudinal direction with a predetermined width. In this way, a plurality of adhesive layers 22 are formed linearly and continuously in at least the longitudinal direction.

[0018] 3 is a longitudinal cross-sectional view of the shielded electric wire 1 shown in FIG. 1. As shown in FIG. 3, when the conductive nonwoven fabric tape 20 is spirally wrapped around the electric wire 10, the adhesive layer 22 adheres to the electric wire 10 and also adheres to the overlapping conductive nonwoven fabric tape 20 that is spirally wrapped around 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 wrapped around the electric wire 10. Furthermore, 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 portion of the lap portion La, but not 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 electrically connected 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 on the entire conductive nonwoven fabric 21.

[0020] 4A and 4B are conceptual diagrams showing the generation of a magnetic field, with (a) showing the magnetic field in a reference example and (b) showing 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 broken line) is generated in a direction perpendicular to the current.

[0021] 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, a magnetic field MF2 (see solid line) is generated on the conductive nonwoven fabric tape side 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 portions 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 a 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 wire 1 according to this embodiment, when the conductive nonwoven fabric tape 20 is spirally wound around the electric wire 10, the area of ​​the lap portion La where the conductive nonwoven fabric tapes 20 overlap each other is defined as S1, and the area of ​​the adhesive layer 22 in the lap portion La is defined as S2.

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[0026] The conductive nonwoven fabric tape 20 according to this embodiment satisfies the above formulas (1) and (2), and as shown in Fig. 4(b), can form a conductive path CP extending in the longitudinal direction of the electric wire 10. Furthermore, because the ratio between the adhesive layer 22 and the conductive portion 23 is optimized, 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 canceled out by the magnetic field MF2 generated by 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 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 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 unique to each product, as in the case of the conductive nonwoven fabric tape disclosed in Japanese Patent Application No. 2022-191625, and is therefore more versatile.

[0028] The conductive nonwoven fabric tape 20 used for spiral winding as described above 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 tape 20 along the longitudinal direction to have a width of t. When the conductive nonwoven fabric tape 20 is used for longitudinal application, it may be finished 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 by forming 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, the conductive nonwoven fabric tape in the shielded electric wire shown in Example 1 has two adhesive layers extending along the longitudinal direction. Similar to that 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 conductivity ratio of 35% as shown in formula (2) and an adhesive ratio of 30% as shown in formula (1). The lap width (width of the lap portion) is 1 / 2 from one end of the conductive nonwoven fabric tape (the area of ​​the lap portion is 1 / 2 of the total area). The shield resistance of the 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 increased. 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, with a conduction ratio of 25% as shown in formula (2) and an adhesive ratio of 50% as shown in formula (1). However, one adhesive layer is formed in the center of one end (half of one end in the width direction), and the other adhesive layer is formed in the center of the other end (half of the other end in the width direction). The shield resistance of this 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 Comparative Example 1, the conductive nonwoven fabric has a conduction ratio of 50% as shown in formula (2) and an adhesive ratio of 0% as shown in formula (1). The wrap width is set to 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 increased. 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 this 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 (which has no adhesive layer and is not a conductive nonwoven fabric tape) is the same as that in Comparative Example 1 (which does not have an adhesive layer). In Comparative Example 3, the conductive nonwoven fabric has a conductivity ratio of 25% as shown in formula (2) and a adhesion ratio of 0% as shown in formula (1). 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 conductivity ratio of 13% as shown in formula (2) and an adhesive ratio of 50% as shown in formula (1). The wrap width is 1 / 4 from one end. The shield resistance of this spirally wound conductive nonwoven fabric tape was 4.34 [Ω / m].

[0037] In the above, an 8d coaxial cable was used as the electric wire inside the conductive nonwoven fabric tape. The adhesive layer was formed using double-sided tape (product number #8080) manufactured by DIC Corporation. The width of the conductive nonwoven fabric tape was 20 mm. The earth part was attached by wrapping a connector around it and tightening a tie band over the conductive nonwoven fabric tape. The tightening force of the tie band was in 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. Note that the shielding effects of Examples 1 and 3 are omitted from Fig. 6 because they are similar to those of Example 2. Similarly, the shielding effect of Comparative Example 3 is similar to that of Comparative Example 1, and the shielding effect of Comparative Example 4 is similar to that of Comparative Example 2, so they are not shown.

[0039] As shown in Fig. 6, the shielded wire according to Comparative Example 1 exhibits the best shielding effect. This is because the conductive nonwoven fabric does not have an adhesive layer, which allows for the formation of a conductive path extending in the longitudinal direction. However, because 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, preventing the good shielding effect shown in Fig. 6 from being obtained. Furthermore, when a conductive nonwoven fabric without an adhesive layer is used, the position of the conductive nonwoven fabric becomes unstable, which may result in the poor shielding effect being obtained after long-term use, etc.

[0040] On the other hand, the shielded wire of Example 2 had the second best shielding effect after the shielded wire of Comparative Example 1. This is because the shielded wire of 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 not only to the wire but also to the conductive nonwoven fabric tape. This reduces the possibility that the lap portion will open or the conductive nonwoven fabric tape will become misaligned when bent, making it easier to obtain a relatively good shielding effect even when bent or after long-term use.

[0041] Furthermore, the shielded wire according to Comparative Example 2 had the lowest shielding effect. The shielded wire according to Comparative Example 2 did not satisfy both the conditions of formula (1) and formula (2), and the shielding resistance exceeded 4.0 [Ω / m]. Therefore, even if a conductive path extending in the longitudinal direction could be formed, it was not enough to cancel out the magnetic field, and it is difficult to say that a good shielding effect was 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 vertically attached example 1 uses a conductive nonwoven fabric without an adhesive layer as the shielding layer. Therefore, the adhesive ratio shown in formula (1) is 0%. The shield resistance of such a vertically attached conductive nonwoven fabric was 0.51 [Ω / m].

[0044] In addition, the conductive nonwoven fabric tape in the shielded wire according to Vertically Attached Example 2 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 Vertically Attached Example 1, the conductive nonwoven fabric tape has an adhesive ratio of 30% as shown in formula (1). 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 Vertically Attached Example 3, the conductive nonwoven fabric tape was the same as that in Vertically Attached Example 2, but the adhesive layer width was increased and the adhesive ratio shown in formula (1) was set to 50%. The shield resistance of the 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 had an adhesive ratio of 50% as shown in formula (1), and the shield resistance of the vertically attached conductive nonwoven fabric tape was 0.52 [Ω / m].

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

[0048] Fig. 8 is a graph showing the shielding effect of the shielded wires 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 is therefore not shown.

[0049] As shown in Fig. 8, the shielded wire according to Vertical Attachment Example 1 has the best shielding effect. In contrast, the shielded wire according to Vertical Attachment Example 3 also has a shielding effect as good as that of the shielded wire according to Vertical Attachment Example 1. The shielded wire according to Vertical Attachment Example 5 has a lower shielding effect than the shielded 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 of Vertical Attachment Examples 1 to 5 satisfy formula (1). Furthermore, 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 designed). The conductive nonwoven fabric tapes shown in Vertical Attachment Examples 2 to 4 have the same shielding effect as the conductive nonwoven fabric of Vertical Attachment Example 1 even when attached vertically, and are therefore highly versatile.

[0051] Thus, according to the shielded wire 1 of this embodiment, the adhesive layer 22 adheres to the wire 10 and also adheres to the conductive nonwoven fabric tape 20 that is spirally wound and overlaps the wire 10. Therefore, the conductive nonwoven fabric tape 20 adheres to the wire 10 to prevent misalignment and also adheres to the conductive nonwoven fabric tape 20 to maintain the wound state. Moreover, the shielded 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 lap portion La is S1 and the area of ​​the adhesive layer 22 in the lap portion La is S2, the shielded wire 1 satisfies formula (2). As a result, the area (S1-S2) in the wrap portion La where conductivity is ensured by the conductive portion 23 is optimized, and a conductive path CP in the longitudinal direction is ensured even when the conductive nonwoven fabric tape 20 is spirally wound. In particular, the conductive nonwoven fabric tape 20 is not limited to those 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, etc., and is unlikely to be one-of-a-kind, and some products can be used in a longitudinal orientation. Therefore, it is possible to provide a shielded wire 1 that can increase the versatility of the conductive nonwoven fabric tape 20 and suppress a decrease in shielding effectiveness.

[0052] Furthermore, the conductive nonwoven fabric tape 20 has a plurality of adhesive layers 22 formed continuously and linearly at least in the longitudinal direction, making it easy to form the adhesive layers 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 it is attached vertically.

[0053] The present invention has been described above based on the embodiments, but the present invention is not limited to the above embodiments, and modifications may be made within the scope of the spirit of the present invention, and if possible, publicly 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 multiple adhesive layers 22 extend along the longitudinal direction, but may be configured to have at least elements extending in the longitudinal direction, such as extending diagonally. This also makes it easy to form the adhesive layer 22 on the conductive nonwoven fabric 21, for example, by using double-sided tape, and also makes it possible to properly wrap the conductive nonwoven fabric tape 20 around the electric wire 10 in a state where it is difficult to peel off even when the tape is attached vertically.

[0055] 9(b), the conductive nonwoven fabric tape 20b may have adhesive layers 22 formed intermittently and at regular intervals in the longitudinal direction. Here, "regular intervals" does not necessarily mean that adhesive layers 22 spaced apart in the longitudinal direction are arranged at regular intervals. For example, "regular intervals" may include a case where first and second adhesive layers 22 spaced apart in the longitudinal direction are arranged at a first interval, and 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 adhesive layers 22 are formed intermittently in this way, the same effect can be obtained as long as formulas (1) and (2) are satisfied.

[0056] Furthermore, as shown in Fig. 9(c), the conductive nonwoven fabric tape 20c may have conductive portions 23 formed intermittently and at regular intervals in the longitudinal direction. Here, "regular intervals" refers to the same as shown in Fig. 9(b). This is because even if the conductive portions 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 the adhesive layer partially formed on the conductive nonwoven fabric, the adhesive layer adheres to the electric wire when the conductive nonwoven fabric tape is spirally wound around the electric wire, and also adheres to the conductive nonwoven fabric tape that overlaps the conductive nonwoven fabric tape when spirally wound; When the width of the spirally wound conductive nonwoven fabric tape is defined as t, the length of the conductive nonwoven fabric tape is defined as L, the area of ​​the adhesive layer of the conductive nonwoven fabric tape is defined as S, the area of ​​the lap portion where the conductive nonwoven fabric tapes overlap each other when the conductive nonwoven fabric tape is spirally wound is defined as S1, and the area of ​​the adhesive layer in the lap portion is defined as S2, [Equation 1] [Equation 2] fulfill A 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 portions where the adhesive layer or 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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