Noise reduction film and wiring harness

Abstract

A noise reduction sheet (1) comprising a flexible sheet (2) containing a soft magnetic material in which a plurality of first grooves (10) extending in a first direction (D1), a plurality of second grooves (20) extending in a second direction (D2), and a plurality of third grooves (30) extending in a third direction (D3) are provided on a first surface (21) of the sheet, the first surface being divided into a plurality of regular triangular regions (21t) by the first grooves, the second grooves, and the third grooves, and each of the first grooves, the second grooves, and the third grooves has a cross-sectional shape in which a groove width increases toward an opening along a depth direction of the groove.

Description

Area

[0001] The present invention relates to a noise reduction film and a wiring harness. background

[0002] Conventionally, there is a method for noise reduction. Patent Literature 1 discloses a ferrite plate obtained by forming a protective layer on sintered ferrite plates subjected to a cutting process to prevent small pieces separated along cuts from falling off. In the ferrite plate of Patent Literature 1, protective layers, each comprising an adhesive layer and a paint layer, are formed on the front and back surfaces of the sintered ferrite plates formed in a square thin foil (sheet) shape with a thickness of 50 μm to 1.0 mm. Citation listPatent documents

[0003] Patent Document 1: Japanese Patent Application Laid-Open No. 2014-225552 SummaryTechnical problem

[0004] In the configuration in which the square sintered ferrite plates are arranged, the bending directions tend to be limited to two mutually orthogonal directions. Therefore, there is a need for a noise reduction film whose degree of freedom in deformation is improved when the noise reduction film is attached to an object.

[0005] An object of the present invention is to provide a noise reduction sheet and a wire harness capable of improving the degree of freedom of deformation. Solution to the problem

[0006] A noise reduction sheet according to the present invention comprises a flexible sheet containing a soft magnetic material, wherein a plurality of first grooves extending in a first direction, a plurality of second grooves extending in a second direction, and a plurality of third grooves extending in a third direction are provided on a first surface of the sheet, the first surface being divided into a plurality of regular triangular regions by the first grooves, the second grooves, and the third grooves, and each of the first grooves, the second grooves, and the third grooves has a cross-sectional shape in which a groove width increases toward an opening along a depth direction of the groove. Advantageous effects of the invention

[0007] The noise-reducing film according to the present invention has grooves in three directions to divide the first surface into a plurality of regular triangular regions. The noise-reducing film according to the present invention with grooves in three directions has the advantage of improving the degree of freedom of deformation. Short description of the drawings Fig. 1 is a plan view of a noise reduction film according to an embodiment. Fig. 2 is a cross-sectional view of the noise reduction film according to the embodiment. Fig. 3 is a plan view of first grooves according to the embodiment. Fig. 4 is a plan view of second grooves according to the embodiment. Fig. 5 is a plan view of third grooves according to the embodiment. Fig. 6 is a plan view showing a regular hexagonal region according to the embodiment. Fig. 7 is a view explaining how the film is wrapped around a cable. Fig. 8 is a cross-sectional view of the first groove according to the embodiment. Fig. 9 is a cross-sectional view of the first groove in the closed state. Fig. 10 is a cross-sectional view of a wire harness according to the embodiment. Fig. 11 is a cross-sectional view showing a narrow portion according to the embodiment. Fig. 12 is a cross-sectional view showing another narrow portion according to the embodiment. Description of the embodiments

[0008] Below, a noise suppression sheet and a wire harness according to an embodiment of the present invention will be described in detail with reference to the drawings. It should be noted that the present invention is not limited to the present embodiment. Furthermore, the components in the following embodiment include those easily conceived by those skilled in the art or those that are substantially the same. [Embodiment]

[0009] In the following, an embodiment is described with reference to the Fig. 1 to 12. The present embodiment relates to a noise reduction sheet and a wire harness. Fig. 1 is a plan view of the noise reduction film according to the embodiment, Fig. 2 is a cross-sectional view of the noise reduction film according to the embodiment, Fig. 3 is a plan view of first grooves according to the embodiment, Fig. 4 is a plan view of second grooves according to the embodiment, Fig. 5 is a plan view of third grooves according to the embodiment, Fig. 6 is a plan view showing a regular hexagonal region according to the embodiment, Fig. 7 is a view for explaining how the film is wrapped around a cable, Fig. 8 is a cross-sectional view of the first groove according to the embodiment, Fig. 9 is a cross-sectional view of the first groove in a closed state, Fig. 10 is a cross-sectional view of a wire harness according to the embodiment, Fig. 11 is a cross-sectional view illustrating a narrow portion according to the embodiment, and Fig. 12 is a cross-sectional view illustrating another narrow portion according to the embodiment.

[0010] A noise suppression sheet 1 according to the present embodiment includes a flexible sheet 2 containing a soft magnetic material such as ferrite. The sheet 2 is, for example, a member in which the soft magnetic material is dispersed in a synthetic resin sheet. The soft magnetic material contained in the sheet 2 may be composed of a large number of thin pieces of soft magnetic material. The synthetic resin may be rubber or polyvinyl chloride (PVC), or another synthetic resin. The synthetic resin for the sheet 2 is an elastically deformable synthetic resin that is flexible in a molded state in a sheet shape.

[0011] As in Fig. As shown in Figure 2, the film 2 has a first surface 21 and a second surface 22. The first surface 21 is a surface facing a noise emitter, such as a cable. The second surface 22 is a surface opposite the first surface 21.

[0012] As in Fig. 1, the first surface 21 is divided into a plurality of regular triangular regions 21t by a plurality of grooves 3. The plurality of grooves 3 are formed, for example, by a mold for molding the film 2. In this case, the mold forming the first surface 21 has protrusions corresponding to the grooves 3. The plurality of grooves 3 includes a plurality of first grooves 10, a plurality of second grooves 20, and a plurality of third grooves 30. The first grooves 10 extend in a first direction D1. The second grooves 20 extend in a second direction D2. The third grooves 30 extend in a third direction D3.

[0013] The first grooves 10, the second grooves 20, and the third grooves 30 form a plurality of regular triangular regions 21t on the first surface 21. An intersection angle of the second direction D2 with respect to the first direction D1 is 60 [°]. That is, in a portion where the first groove 10 and the second groove 20 intersect each other, the intersection angle of the second groove 20 on the acute angle side with respect to the first groove 10 is 60 [°]. Similarly, an intersection angle of the third direction D3 with the second direction D2 is 60 [°]. That is, in a portion where the second groove 20 and the third groove 30 intersect each other, the intersection angle of the third groove 30 on the acute angle side with respect to the second groove 20 is 60 [°]. An intersection angle of the first direction D1 with respect to the third direction D3 is 60 [°].That is, in a section where the third groove 30 and the first groove 10 intersect, the intersection angle of the first groove 10 on the acute angle side with respect to the third groove 30 is 60 [°]. The first groove 10, the second groove 20, and the third groove 30 are arranged to intersect at the same intersection point.

[0014] Fig. 2 shows a cross-sectional shape of the groove 3. The cross-sectional shape of the groove 3 is a shape in which a groove width Wd increases toward an opening 3a along a depth direction Z of the groove 3. The exemplary groove 3 has a curved wall 3b and a pair of straight walls 3c. The curved wall 3b is a wall portion having a curved cross-sectional shape. The curved wall 3b is provided at the bottom of the groove 3. The cross-sectional shape of the curved wall 3b is, for example, an arc shape or a hyperbolic shape. The cross-sectional shape of the curved wall 3b is preferably a continuously curved shape. The curved wall 3b is curved outward in the direction of the groove width W, that is, the groove 3 has a cross-sectional shape curved outward in the direction of the groove width W.

[0015] The straight walls 3c are provided on the opening 3a side in the groove 3. The pair of straight walls 3c face each other in the groove width W direction. The straight wall 3c is inclined with respect to the depth direction Z of the groove 3. More specifically, the pair of straight walls 3c is inclined so that the groove width Wd increases toward the opening 3a along the depth direction Z. The straight walls 3c are continuous with the curved wall 3b. An extension direction of the straight wall 3c is a tangential direction of one end of the curved wall 3b.

[0016] The groove 3 is provided beyond a center line Zm in the depth direction Z of the film 2 toward the second surface 22. That is, a depth Z2 of the groove 3 is greater than half the thickness Z1 of the film 2. The thickness Z1 of the film 2 is determined to achieve a desired noise reduction effect. For the noise reduction film 1 attached to a charging cable, the thickness Z1 of the film 2 can be several millimeters. The thickness Z3 from the bottom of the groove 3 to the second surface 22 is determined by considering the balance between the flexibility of the film 2, the strength of the film 2, and the noise reduction effect.

[0017] On the Fig. 3, only the first grooves 10 are shown, while the second grooves 20 and the third grooves 30 are not shown. As in Fig. As shown in Figure 3, the plurality of first grooves 10 are arranged at equal intervals, each forming a pitch G1. The pitch G1 is an interline pitch in a direction orthogonal to the first direction D1. The interline pitch is a distance from the center of a first groove 10 to the center of the adjacent first groove 10.

[0018] The first groove 10 includes first portions 10a and second portions 10b. In the first groove 10, the first portions 10a and the second portions 10b are arranged alternately along the first direction D1. The second portion 10b is a narrow portion with a smaller groove width Wd than the first portion 10a. When the groove width Wd of the first portion 10a is Wd1 and the groove width Wd of the second portion 10b is Wd2, the following formula (1) is established at the same position in the depth direction Z. Wd1>Wd2

[0019] A length L1 of the first portion 10a is the length of one side of the regular triangular region 21t. A length L2 of the second portion 10b is twice the length L1 of the first portion 10a. The first portion 10a of the first groove 10 is opposite to the second portion 10b of the adjacent first groove 10. That is, the first portions 10a and the second portions 10b are arranged alternately in the direction orthogonal to the first direction D1.

[0020] On the Fig. 4, only the second grooves 20 are shown, while the first grooves 10 and the third grooves 30 are not shown. As in Fig. As shown in Figure 4, the plurality of second grooves 20 are arranged at equal intervals, each forming a pitch G1. The pitch G1 is an interline pitch in a direction orthogonal to the second direction D2.

[0021] The second groove 20 includes first portions 20a and second portions 20b. In the second groove 20, the first portions 20a and the second portions 20b are arranged alternately along the second direction D2. The second portion 20b is a narrow portion with a smaller groove width Wd than the first portion 20a. When the groove width Wd of the first portion 20a is Wd1 and the groove width Wd of the second portion 20b is Wd2, the above formula (1) is established at the same position in the depth direction Z.

[0022] The first portion 20a has the same length L1 as the first portion 10a of the first groove 10, and the second portion 20b has the same length L2 as the second portion 10b of the first groove 10. The first portion 20a of the second groove 20 is opposite to the second portion 20b of the adjacent second groove 20. That is, the first portions 20a and the second portions 20b are arranged alternately in the direction orthogonal to the second direction D2.

[0023] On the Fig. 5, only the third grooves 30 are shown, while the first grooves 10 and the second grooves 20 are not shown. As in Fig. As shown in Figure 5, the plurality of third grooves 30 are arranged at equal intervals, each forming a pitch G1. The pitch G1 is an interline pitch in a direction orthogonal to the third direction D3.

[0024] The third groove 30 includes first portions 30a and second portions 30b. In the third groove 30, the first portions 30a and the second portions 30b are arranged alternately along the third direction D3. The second portion 30b is a narrow portion with a smaller groove width Wd than the first portion 30a. When the groove width Wd of the first portion 30a is Wd1 and the groove width Wd of the second portion 30b is Wd2, the above equation (1) is established at the same position in the depth direction Z.

[0025] The first portion 30a has the same length L1 as the first portion 10a of the first groove 10, and the second portion 30b has the same length L2 as the second portion 10b of the first groove 10. The first portion 30a of the third groove 30 is opposite to the second portion 30b of the adjacent third groove 30. That is, the first portions 30a and the second portions 30b are arranged alternately in the direction orthogonal to the third direction D3.

[0026] As in Fig. As shown in Figure 1, the first grooves 10, the second grooves 20, and the third grooves 30 are arranged to divide the first surface 21 into a plurality of regular hexagonal regions 21h. The plurality of regular hexagonal regions 21h form a honeycomb structure.

[0027] As in Fig. As shown in Figure 6, the regular hexagonal region 21h is formed by a pair of first sections 10a, a pair of first sections 20a, and a pair of first sections 30a. The second sections 10b, 20b, and 30b are diagonal sections of the regular hexagonal region 21h. A regular hexagonal region 21h comprises six regular triangular regions 21t. A regular hexagonal region 21h is adjacent to six other regular hexagonal regions 21h and surrounded by the six regular hexagonal regions 21h. Two adjacent hexagonal regions 21h are divided by a first section 10a, a first section 20a, or a first section 30a.

[0028] As from Fig. As can be seen from Figure 1, the first surface 21 is divided into a plurality of regular hexagonal regions 21h forming the honeycomb structure. As described below, the noise reduction sheet 1 according to the present embodiment has a high degree of freedom in deformation when attached to an object.

[0029] Fig. Figure 7 shows the noise-reducing film 1 wrapped around a cable 100. The cable 100 is, for example, a charging cable for supplying power to a vehicle. The charging cable can be a standard charging cable or a rapid charging cable. The film 2 is wrapped around the cable 100 such that the cable 100 is covered by the first surface 21.

[0030] The flexible film 2 can be elastically deformed when the film 2 is wound around the cable 100. The film 2 according to the present embodiment is further deformed so that the grooves 3 are closed, whereby the film 2 can be easily bent. The grooves 3 include the first grooves 10, the second grooves 20, and the third grooves 30 extending in three different directions. Therefore, when the film 2 is wound around the cable 100, the degree of freedom of deformation of the film 2 is high. As a comparative example, a ferrite plate in which sintered ferrite plates are arranged in a square thin film shape (foil shape) will be discussed. The ferrite plate according to the comparative example can be bent in two orthogonal directions, but it is difficult to cope flexibly with other directions.

[0031] Since grooves 3 extending in three different directions are provided in the noise reduction sheet 1 according to the present embodiment, it is possible to flexibly cope with bends in various directions. Furthermore, the sheet 2 according to the present embodiment, which is attached to the cable 100, can appropriately follow the deformation of the cable 100. For example, the sheet 2 according to the present embodiment can flexibly follow the bending and stretching of the cable 100 or the like. By appropriately deforming the grooves 3 extending in the three directions according to the bent shape of the cable 100, the sheet 2 can follow the deformation of the cable 100. Furthermore, by appropriately deforming the grooves 3 extending in the three directions, the stress in the sheet 2 is dispersed.

[0032] Furthermore, the noise reduction sheet 1 according to the present embodiment can flexibly cope with cables 100 of different diameters. The groove width Wd of the groove 3 can be adjusted so that the noise reduction sheet 1 can be wound around a cable 100 with an assumed minimum diameter. In this case, in a state where the noise reduction sheet 1 is wound around a large-diameter cable 100, the grooves 3 may be open and not completely closed. However, the opening width of the groove 3 after the sheet 2 is wound around the cable 100 is narrower than the opening width of the groove 3 before the sheet 2 is wound around the cable 100. Therefore, the noise reduction sheet 1 has a sufficient noise reduction effect even when wound around the large-diameter cable 100.

[0033] In the noise reduction film 1 according to the present embodiment, the grooves 3 comprise the first portions 10a, 20a, and 30a and the second portions 10b, 20b, and 30b. This suppresses uneven deformation and stress concentration in the film 2. As an example, the deformation of the film 2, by which the first groove 10 is closed, will be described as shown in Fig. 8. In this case, the film 2 is bent while the first portions 10a and the second portions 10b of the first groove 10 are closed. The second portion 10b, with a narrow groove width Wd, is completely closed earlier than the first portion 10a.

[0034] Fig. 9 shows a cross-section through the closed second section 10b. The groove 3 according to the present embodiment is designed such that when the groove 3 is closed, the wall surfaces on both sides adhere to each other. For example, the shape of the groove 3 is designed such that the groove 3 is closed without a gap from the bottom of the groove 3 to the opening 3a of the groove 3. Alternatively, the shape of the groove 3 is designed such that at least the opening 3a of the groove 3 is closed without a gap. As a result, the noise reduction film 1 has a sufficient noise reduction effect.

[0035] The closed second portion 10b generates a reaction force against the bending force F1. That is, the rigidity against the bending force F1 is high in the first groove 10. When the sheet 2 is further bent from this state, the first portion 10a can be further closed in the first groove 10. At the same time, this increases the rigidity in the first grooves 10, promoting the bending of portions of the sheet 2 other than the first grooves 10. That is, the sheet 2 can be bent as easily as if the entire sheet 2 were curved. As a result, the cross-sectional shape of the sheet 2 takes on a shape corresponding to the cross-sectional shape of the cable 100. In other words, there is hardly any gap between an outer peripheral surface of the cable 100 and the first surface 21 of the sheet 2. Therefore, the noise suppression sheet 1 according to the present embodiment easily adheres to the cable 100, making it possible to suppress noise leakage.

[0036] The deformation of the film 2, which closes the second grooves 20 and the third grooves 30, has the same effect. Therefore, the noise reduction film 1 according to the present embodiment has a high degree of freedom in deformation when attached to an object and a high adaptability to the shape of the object.

[0037] Fig. 10 shows a wire harness WH to which the noise-suppressing film 1 according to the present embodiment is applied. The wire harness WH includes a cable 100 and the noise-suppressing film 1 wound around the cable 100 with the first surface 21 facing inward. The noise-suppressing film 1 is attached to the cable 100. A means for attaching the noise-suppressing film 1 to the cable 100 may be a fastening member such as a binding tape, an adhesive or an adhesive film, or other means.

[0038] The noise reduction film 1 covers the entire circumference of the cable 100. The noise reduction film 1 can be wrapped around the cable 100 so that their end portions overlap each other. In this case, the end portion of the first surface 21 overlaps with the end portion of the second surface 22. The noise reduction film 1 is configured to reduce the noise emission of the cable 100 to the outside. As described below, the groove width Wd of the groove 3 according to the present embodiment is determined according to a wavelength of a noise to be reduced (hereinafter simply referred to as "target wavelength λ").

[0039] The target wavelength λ is determined, for example, based on a current flowing through the cable 100. When a current flows through the cable 100, noise is emitted from the cable 100. The target wavelength λ is determined from the wavelength of the emitted noise. The target wavelength λ is, for example, the wavelength of a noise with the highest frequency among the emitted noise. The target wavelength λ can be a wavelength corresponding to a frequency of a circuit connected to the cable 100.

[0040] As in Fig. As shown in Figure 11, the groove 3 according to the present embodiment has a narrow portion 3d. The narrow portion 3d is a portion whose groove width Wd is half the wavelength λ / 2 or shorter than the target wavelength λ. The narrow portion 3d includes the bottom of the groove 3 and is provided in a predetermined range along the groove width direction W. The narrow portion 3d can regulate the transmission of noise with the target wavelength λ in a state where the film 2 has a flat film shape, as shown in Figure 11. Fig. 11. The narrow portion 3d can regulate the transmission of noise with a wavelength longer than the target wavelength λ. When the film 2 is attached to an object, the groove width Wd of the narrow portion 3d decreases. That is, in the groove 3, a portion that can regulate the transmission of noise with the target wavelength λ expands toward the opening 3a. Therefore, the noise reduction film 1 according to the present embodiment can effectively reduce noise with a wavelength equal to or longer than the target wavelength λ.

[0041] The grooves 3 may have narrow sections 3d in both the first sections 10a, 20a, and 30a and the second sections 10b, 20b, and 30b. In this case, the second sections 10b, 20b, and 30b, which have a relatively narrow width, may be completely narrow sections 3d. In the second sections 10b, 20b, and 30b, which are completely narrow sections 3d, the groove width Wd of the opening 3a corresponds to half the wavelength λ / 2 or less.

[0042] In the first sections 10a, 20a, and 30a, the range in which the narrow portion 3d is provided is arbitrary. For example, the narrow portion 3d may be provided in a range from the center line Zm to the bottom of the groove 3. In this case, the groove width Wd at the center line Zm corresponds to half the wavelength λ / 2. The narrow portion 3d may be provided closer to the bottom of the groove 3 than the center line Zm, without including the center line Zm. Alternatively, the narrow portion 3d may be provided in a range from a position of half the depth Z2 of the groove 3 to the bottom.

[0043] The cross-sectional shape of the groove 3 is not limited to the shape shown as an example. For example, the groove 3 need not have straight walls 3c. In this case, the groove 3 can have a completely curved wall 3b. The groove 3 does not need to have a curved wall 3b. Fig. 12 shows an example of a cross-sectional shape of the groove 3 which does not have a curved wall 3b. Fig. The cross-sectional shape of the groove 3 shown in Figure 12 is V-shaped. The groove 3 has a pair of straight walls 3c. The bottom of the groove 3 may be provided closer to the second surface 22 than to the center line Zm. The groove 3 has a narrow section 3d with a groove width Wd equal to or less than half the wavelength λ / 2. The narrow section 3d may be provided in a range from the center line Zm to the bottom of the groove 3.

[0044] As described above, the noise reduction sheet 1 according to the present embodiment includes the flexible sheet 2 containing a soft magnetic material. The plurality of first grooves 10 extending in the first direction D1, the plurality of second grooves 20 extending in the second direction D2, and the plurality of third grooves 30 extending in the third direction D3 are provided on the first surface 21 of the sheet 2. The first surface 21 is divided into a plurality of regular triangular regions 21t by the first grooves 10, the second grooves 20, and the third grooves 30. Each of the first grooves 10, the second grooves 20, and the third grooves 30 has a cross-sectional shape in which the groove width Wd increases toward the opening 3a along the depth direction Z of the groove 3.Since the noise reduction sheet 1 according to the present embodiment has a plurality of grooves 3 extending in three directions, it is possible to improve the degree of freedom of deformation when the noise reduction sheet 1 is attached to an object.

[0045] The noise suppression sheet 1 according to the present embodiment can be manufactured at a lower cost than a conventional ferrite core. Furthermore, a special jig or the like is not required when attaching the noise suppression sheet 1 to an object. Therefore, the noise suppression sheet 1 according to the present embodiment has a high cost-reduction effect. Furthermore, the noise suppression sheet 1 according to the present embodiment can achieve marketability improvement through weight reduction. Furthermore, the noise suppression sheet 1 according to the present embodiment can also meet customer needs (EMC measures, cost reduction through productivity improvement).

[0046] Each of the first grooves 10, the second grooves 20, and the third grooves 30 according to the present embodiment includes the first portions 10a, 20a, or 30a and the second portions 10b, 20b, or 30b. The second portions 10b, 20b, or 30b have a smaller groove width Wd than the first portions 10a, 20a, or 30a. In each of the grooves, the first portions 10a, 20a, or 30a and the second portions 10b, 20b, or 30b are alternately arranged. The first portions 10a, 20a, or 30a are arranged such that the first surface 21 is divided into regular hexagonal regions 21h forming a honeycomb structure. The sheet 2 configured as described above can be flexibly deformed while suppressing stress concentrations.

[0047] The second portions 10b, 20b, or 30b according to the present embodiment are diagonal portions in the regular hexagonal regions 21h. Since the regular hexagonal regions 21h have diagonal grooves, the degree of freedom in deformation of the film 2 is improved. For example, the regular hexagonal regions 21h flexibly adapt to the curved surface.

[0048] Each of the first grooves 10, the second grooves 20, and the third grooves 30 according to the present embodiment has a cross-sectional shape curved outward in the direction of the groove width W. In the groove 3 with such a shape, the opening 3a is easily closable when the groove 3 is closed.

[0049] The wire harness WH according to the present embodiment includes the cable 100 and the above noise suppression film 1. The noise suppression film 1 is wound around the cable 100 with the first surface 21 facing inward. Each of the first grooves 10, the second grooves 20, and the third grooves 30 has a narrow portion 3d in which the groove width Wd is narrower than a predetermined width when the noise suppression film 1 has a flat film shape. The narrow portion 3d is provided in a predetermined range from the bottom in the depth direction Z of the groove 3. The predetermined width corresponds to half the wavelength λ / 2 of the noise generated by a current flowing through the cable 100. The wire harness WH including the noise suppression film 1 can effectively reduce the noise emanating from the cable 100.

[0050] The specific configurations of the first grooves 10, the second grooves 20, and the third grooves 30 are not limited to those shown in the embodiment. For example, the number of regular triangular regions 21t included in the regular hexagonal region 21h is not limited to six. The regular hexagonal region 21h may include more than six regular triangular regions 21t.

[0051] The depth Z2 of the groove 3 may differ between the first sections 10a, 20a, or 30a and the second sections 10b, 20b, or 30b. In this case, the second sections 10b, 20b, or 30b may have a smaller depth than the first sections 10a, 20a, or 30a. As a result, the second sections 10b, 20b, or 30b have a higher stiffness against a bending force F1 than the first sections 10a, 20a, or 30a.

[0052] The first grooves 10, the second grooves 20, and the third grooves 30 need not have second sections 10b, 20b, and 30b. In this case, the groove width Wd is constant along an extension direction of the groove 3.

[0053] The above-mentioned embodiments can be carried out in suitable combination. List of reference symbols 1 noise reduction film 2 slides 3 grooves 3a Opening 3b Curved wall 3c Straight Wall 3d Narrow section 10 First groove 10a First Section 10b Second Section 20 Second groove 20a First Section 20b Second Section 30 Third groove 30a First Section 30b Second Section 21 First area 21h Hexagonal area 21t Triangular area 22 Second area D1 First Direction D2 Second Direction D3 Third Direction G1 distance L1 Length of the first section L2 Length of the second section W Groove width direction Wd groove width Wd1 Groove width of the first section Wd2 Groove width of the second section Z Depth direction λ Target wavelength λ / 2 Half wavelength QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] JP 2014- 225 552

[0003]

Claims

[1] Noise reduction film, comprising: a flexible film containing a soft magnetic material, wherein a plurality of first grooves extending in a first direction, a plurality of second grooves extending in a second direction, and a plurality of third grooves extending in a third direction are provided on a first surface of the film, the first surface is divided into a plurality of regular triangular regions by the first grooves, the second grooves and the third grooves, and each of the first grooves, the second grooves and the third grooves has a cross-sectional shape in which a groove width increases toward an opening along a groove depth direction. [2] A noise reduction film according to claim 1, wherein each of the first grooves, the second grooves and the third grooves comprises first sections and second sections having a smaller groove width than the first sections, the first sections and the second sections being arranged alternately, and the first sections are arranged such that the first surface is divided into a plurality of regular hexagonal regions forming a honeycomb structure. [3] The noise reduction film according to claim 2, wherein the second portions are diagonal portions in the regular hexagonal regions. [4] The noise reduction film according to any one of claims 1 to 3, wherein each of the first grooves, the second grooves and the third grooves has a cross-sectional shape curved outward in a groove width direction. [5] Wiring harness, comprising: a cable; and translation of the originally filed PCT claims the noise reduction film according to any one of claims 1 to 3, wherein the noise reduction film is wrapped around the cable with the first surface facing inward, wherein each of the first grooves, the second grooves and the third grooves has a narrow portion in which a groove width is narrower than a predetermined width in a case where the noise reduction film has a flat film shape, the narrow portion is provided in a predetermined range from a bottom in the groove depth direction, and the specified width corresponds to half a wavelength of noise generated by a current flowing through the cable.

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