Wire harness

Abstract

To provide a wire harness capable of reducing the weight of a plate member while achieving a required depth of a potting layer.SOLUTION: A wire harness 1 includes a flexible printed circuit board 3, a chip fuse 6 mounted on the flexible printed circuit board, a plate member 4 having a flat plate body 40 having a frame shape and a tubular peripheral wall 41 projecting from the plate body toward a thickness direction of the plate body, and a potting agent 5, the plate body is fixed to the flexible printed circuit board so as to surround the chip fuse by the peripheral wall, and the potting agent is filled in a space 4s surrounded by the peripheral wall to cover the chip fuse.SELECTED DRAWING: Figure 6

Description

[Technical Field]

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

[0002] Conventionally, there is a technology for covering electronic components with a potting agent. Patent Document 1 discloses a conductive module including a flexible printed wiring board, electronic components mounted on the flexible printed wiring board, a metal plate having a frame surrounding the electronic components, and a potting agent that is filled into the area surrounded by the frame to cover the electronic components. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2023-173467 Summary of the Invention [Problem to be solved by the invention]

[0004] In Patent Document 1, when a metal plate having a thickness corresponding to the required depth of the potting layer is used, the weight of the metal plate tends to be large. It is desirable to be able to reduce the weight of the plate member while realizing the required depth of the potting layer.

[0005] An object of the present invention is to provide a wire harness that can reduce the weight of a plate member while achieving the required depth of a potting layer. [Means for solving the problem]

[0006] The wire harness of the present invention comprises a flexible printed circuit board, a chip fuse mounted on the flexible printed circuit board, a plate member having a flat, frame-shaped plate body and a cylindrical peripheral wall protruding from the plate body in the thickness direction of the plate body, and a potting material, wherein the plate body is fixed to the flexible printed circuit board so as to surround the chip fuse with the peripheral wall, and the potting material is filled in a space surrounded by the peripheral wall to cover the chip fuse. [Effects of the Invention]

[0007] In the wire harness according to the present invention, the plate member has a frame-shaped, flat plate body and a cylindrical peripheral wall protruding from the plate body in the thickness direction of the plate body. The plate body is fixed to the flexible printed circuit board so that the peripheral wall surrounds the chip fuse. The potting material is filled in the space surrounded by the peripheral wall to cover the chip fuse. The wire harness according to the present invention has the effect of reducing the weight of the plate member while achieving the required potting layer depth. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram showing a wire harness according to an embodiment. [Figure 2] FIG. 2 is an exploded perspective view of the wire harness according to the embodiment. [Figure 3] FIG. 3 is a plan view of the flexible printed circuit board according to the embodiment. [Figure 4] FIG. 4 is a plan view of the plate member according to the embodiment. [Figure 5] FIG. 5 is a cross-sectional view of a plate member according to the embodiment. [Figure 6] FIG. 6 is a plan view of the wire harness according to the embodiment. [Figure 7] FIG. 7 is a cross-sectional view of the wire harness according to the embodiment. [Figure 8] FIG. 8 is a plan view of another wire harness according to the embodiment. [Figure 9] FIG. 9 is a cross-sectional view of another wire harness according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, a wire harness according to an embodiment of the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiment. Furthermore, components in the following embodiments include those that can be easily imagined by a person skilled in the art or those that are substantially the same.

[0010] [Embodiment] An embodiment will be described with reference to Figs. 1 to 9. The embodiment relates to a wire harness. Fig. 1 is a diagram showing the wire harness according to the embodiment, Fig. 2 is an exploded perspective view of the wire harness according to the embodiment, Fig. 3 is a plan view of a flexible printed circuit board according to the embodiment, Fig. 4 is a plan view of a plate member according to the embodiment, Fig. 5 is a cross-sectional view of the plate member according to the embodiment, Fig. 6 is a plan view of the wire harness according to the embodiment, Fig. 7 is a cross-sectional view of the wire harness according to the embodiment, Fig. 8 is a plan view of another wire harness according to the embodiment, and Fig. 9 is a cross-sectional view of another wire harness according to the embodiment. Fig. 5 shows a VV cross section of Fig. 4. Fig. 7 shows a VII-VII cross section of Fig. 6.

[0011] As shown in Fig. 1, the wire harness 1 of this embodiment includes a flexible printed circuit board 3, chip fuses 6, a plate member 4, and a potting material 5. In the illustrated wire harness 1, a plurality of chip fuses 6 are mounted on the flexible printed circuit board 3. A plurality of plate members 4 are also arranged on the flexible printed circuit board 3 in accordance with the plurality of chip fuses 6. The wire harness 1 can be combined with a case 2 and a plurality of bus bars 10 to form a bus bar module 200.

[0012] The wire harness 1 and the busbar module 200 are applied to, for example, a battery module 110 of a battery pack 100. The battery module 110 has a plurality of battery cells 120 arranged in an arrangement direction AR. The battery pack 100 is mounted as a power source in a vehicle such as an electric vehicle or a hybrid electric vehicle.

[0013] The busbar 10 is a conductor formed from a conductive metal plate and is fixed to the electrode of the battery cell 120. The busbar 10 connects, for example, two adjacent battery cells 120 in series. The flexible printed circuit board 3 connects the multiple busbars 10 to a monitoring device 130 of the battery pack 100. The flexible printed circuit board 3 may connect a thermistor arranged in the battery cell 120 to the monitoring device 130. The monitoring device 130 is a device that monitors the state of the battery cell 120, such as its voltage and temperature.

[0014] The flexible printed circuit board 3 is connected to the monitoring device 130 via, for example, a connector. The flexible printed circuit board 3 has a plurality of detection lines 9. Each detection line 9 is a circuit pattern formed of a conductive metal. The detection lines 9 are connected to the circuit of the monitoring device 130.

[0015] The detection line 9 is connected to the bus bar 10 via a chip fuse 6 mounted on the flexible printed circuit board 3. The chip fuse 6 is a protective component that protects the circuit. The chip fuse 6 has two electrodes and a fusible portion. The fusible portion melts when an overcurrent flows between the two electrodes.

[0016] In the wire harness 1 of this embodiment, a plate member 4 is interposed between the chip fuse 6 and the bus bar 10. The plate member 4 is connected to the bus bar 10 by welding or the like, and electrically connects the chip fuse 6 and the bus bar 10. The plate member 4 of this embodiment is arranged on the flexible printed circuit board 3 as a voltage detection terminal that detects the voltage of the battery cell 120. The plate member 4 functions as a reinforcing plate that reinforces the flexible printed circuit board 3. The plate member 4 also has a space 4s that accommodates the chip fuse 6. As will be described later, a potting agent 5 is filled in the space 4s formed by the plate member 4 and covers the chip fuse 6.

[0017] The case 2 houses and holds the flexible printed circuit board 3 and the bus bars 10. The case 2 is molded from, for example, an insulating synthetic resin. The case 2 has a wiring path in which the flexible printed circuit board 3 is routed and a plurality of holding portions lined up along the wiring path. Each bus bar 10 is held by a corresponding holding portion. The wire harness 1 may have a cover that covers the flexible printed circuit board 3 and the bus bars 10. In this case, the cover may be integral with the case 2.

[0018] As shown in FIG. 2, the flexible printed circuit board 3 has one trunk line 30 and multiple branch portions 31. The flexible printed circuit board 3 has a base film, a coverlay, and a conductive layer. The base film and the coverlay are flexible insulating resin layers. The conductive layer is sandwiched between the base film and the coverlay for protection. The conductive layer is, for example, a conductive metal foil and has multiple circuit patterns including detection lines 9.

[0019] The main line 30 has a longitudinal direction X and a width direction Y. The width direction Y is perpendicular to the longitudinal direction X. A plurality of detection lines 9 extend along the main line 30. The branch portions 31 branch off from edges of the main line 30 in the width direction Y. In this embodiment, the branch portions 31 extend from the main line 30 in the width direction Y.

[0020] The chip fuse 6 is mounted in a mounting area 32 provided at the tip of the branch portion 31. The mounting area 32 is an area that is widened in the longitudinal direction X and has a substantially rectangular shape. The plate member 4 is fixed to the flexible printed circuit board 3 so that the peripheral wall 41 surrounds the chip fuse 6.

[0021] 3, the conductive layer of the flexible printed circuit board 3 has a detection line 9, a first pad 11, a second pad 12, a third pad 13, and a connection line 14. The first pad 11, the second pad 12, the third pad 13, and the connection line 14 are arranged in a mounting region 32 of the branch portion 31. The pads 11, 12, and 13 are exposed to the external space. In other words, the coverlay has openings that expose the pads 11, 12, and 13.

[0022] The illustrated first pad 11 and second pad 12 are aligned along the longitudinal direction X. The first pad 11 and second pad 12 are joints where the electrodes of the chip fuse 6 are connected. The electrodes of the chip fuse 6 are joined to the pads 11 and 12, for example, by solder. By joining the two electrodes to the pads 11 and 12, the chip fuse 6 is mounted on the flexible printed circuit board 3. Of the two electrodes of the chip fuse 6, one electrode is connected to the first pad 11 and the other electrode is connected to the second pad 12. In other words, the chip fuse 6 is mounted on the branch portion 31 so as to extend in the longitudinal direction X. The detection line 9 is connected to the first pad 11 from the trunk line 30 via the branch portion 31.

[0023] The third pads 13 are joining points to which the plate member 4 is connected. The plate member 4 is joined to the third pads 13 by, for example, soldering, and mounted on the flexible printed circuit board 3. In this embodiment, two third pads 13 are provided in the mounting area 32. The two third pads 13 are arranged on both sides of the pads 11 and 12 in the width direction Y. The connection wire 14 connects the second pad 12 and the two third pads 13. Therefore, the third pads 13 are connected to the detection line 9 via the connection wire 14 and the chip fuse 6.

[0024] As shown in FIGS. 2, 4, and 5, the plate member 4 has a plate body 40 and a cylindrical peripheral wall 41. The plate member 4 is a rigid member that forms a space 4s into which a potting material 5 is filled. The plate member 4 is formed of, for example, a conductive metal. The plate member 4 has an opening 44, and is fixed to the flexible printed circuit board 3 so that the opening 44 faces the chip fuse 6. The illustrated opening 44 has a rectangular shape.

[0025] The plate body 40 is flat and frame-shaped. The illustrated shape of the plate body 40 is a rectangular frame. The plate body 40 has a first surface 40a and a second surface 40b. The first surface 40a and the second surface 40b are the two main surfaces of the plate body 40. The first surface 40a is a flat surface and is connected to the third pad 13 of the flexible printed circuit board 3. In other words, the first surface 40a is the surface of the two main surfaces of the plate body 40 that faces the flexible printed circuit board 3. The second surface 40b is a flat surface and is the surface opposite to the first surface 40a.

[0026] The peripheral wall 41 protrudes from the plate body 40 in the thickness direction T of the plate body 40. The illustrated peripheral wall 41 protrudes from the second surface 40b in a direction perpendicular to the second surface 40b. The cross-sectional shape of the peripheral wall 41 in a cross section perpendicular to the thickness direction T is rectangular. That is, the illustrated peripheral wall 41 has a square cylindrical shape. The peripheral wall 41 is formed, for example, by burring a metal plate. In this case, the peripheral wall 41 is formed by burring a flat metal plate that is the base material of the plate member 4. The peripheral wall 41 is formed by deforming the edge surrounding the opening 44.

[0027] As shown in FIG. 5 , the peripheral wall 41 is connected to the inner edge 40c of the plate body 40. In a cross section along the thickness direction T, the peripheral wall 41 is curved in a substantially arc shape. The peripheral wall 41 has an inner wall surface 42 and an outer wall surface 43. The inner wall surface 42 is a surface facing the space 4s surrounded by the peripheral wall 41. The inner wall surface 42 is continuous with the first surface 40a of the plate body 40. The outer wall surface 43 is a surface of the peripheral wall 41 opposite to the inner wall surface 42. The outer wall surface 43 is continuous with the second surface 40b of the plate body 40.

[0028] The peripheral wall 41 has a tapered shape in which the distance L1 decreases with increasing distance from the plate body 40 in the thickness direction T. The distance L1 is the distance between the opposing inner wall surfaces 42. In the cross section of Figure 5, the inner wall surface 42 and the outer wall surface 43 have a curved shape that curves toward the space 4s.

[0029] The peripheral wall 41 has a tip surface 41a. A distance Z1 in the thickness direction T from the first surface 40a to the tip surface 41a is greater than the height of the chip fuse 6. In other words, the peripheral wall 41 can form a space 4s deep enough to accommodate the entire chip fuse 6.

[0030] The metal plate constituting the plate member 4 has a thickness t. The thickness t of the plate main body 40 is smaller than the distance Z1 from the first surface 40a to the tip surface 41a. In other words, the depth (distance Z1) of the space 4s formed by the plate member 4 of this embodiment is greater than the thickness t of the plate main body 40.

[0031] 6 shows the chip fuse 6 and plate member 4 mounted on a flexible printed circuit board 3. The plate body 40 of the plate member 4 is fixed to the flexible printed circuit board 3 so as to surround the chip fuse 6 with the peripheral wall 41. In other words, the plate body 40 is fixed to the flexible printed circuit board 3 so as to accommodate the chip fuse 6 in the space 4s surrounded by the peripheral wall 41. A gap is provided between the peripheral wall 41 and the chip fuse 6, into which the potting material 5 is filled.

[0032] In the wire harness 1 of this embodiment, the plate body 40 is joined to the third pad 13 of the flexible printed circuit board 3 and fixed to the flexible printed circuit board 3. The plate member 4 is connected to the detection line 9 via the chip fuse 6. A space 4s surrounded by the peripheral wall 41 is filled with a potting agent 5.

[0033] The busbar 10 is arranged, for example, alongside the branch portion 31 in the longitudinal direction X. The plate body 40 of the plate member 4 is connected to the busbar 10 by welding or the like. The plate body 40 is joined to the busbar 10, for example, such that an end of the plate body 40 overlaps the busbar 10.

[0034] 7, the potting material 5 is filled into the space 4s surrounded by the peripheral wall 41 to cover the chip fuse 6. The depth H1 of the potting layer is greater than the height H2 of the chip fuse 6. The potting material 5 covers the top surface 6t of the chip fuse 6, sealing the chip fuse 6.

[0035] The thickness t of the plate body 40 of this embodiment is smaller than the height H2 of the chip fuse 6. That is, in the wire harness 1 of this embodiment, a potting layer having a depth H1 that can accommodate the entire chip fuse 6 is formed, while the thickness t is reduced to achieve weight reduction. For example, the weight of the plate member 4 can be reduced compared to when the plate member is formed from a metal plate having the same thickness as the depth H1.

[0036] The extending direction of the plate member 4 and the relative position of the bus bar 10 with respect to the branch portion 31 can be set as appropriate. The extending direction of the plate member 4 and the relative position of the bus bar 10 with respect to the branch portion 31 are determined, for example, in accordance with the battery module 110. FIG. 8 shows the plate member 4 extending from the branch portion 31 in the width direction Y. The bus bar 10 in FIG. 8 is arranged in line with the branch portion 31 in the width direction Y. The plate body 40 of the plate member 4 extends from the branch portion 31 in the width direction Y and is connected to the bus bar 10. The plate body 40 is fixed to the branch portion 31 of the flexible printed circuit board 3 so as to surround the chip fuse 6 with a peripheral wall 41. In the flexible printed circuit board 3 in FIG. 8, two third pads 13 are arranged on both sides of the chip fuse 6 in the longitudinal direction X. The plate body 40 is connected to the third pads 13 by solder or the like.

[0037] The method for forming the peripheral wall 41 on the plate member 4 is not limited to burring. For example, the plate body 40 and the peripheral wall 41 may be formed by machining a metal plate, such as by cutting. For example, the plate body 40 and the peripheral wall 41 may be formed by machining the outer edge of a metal plate to reduce its thickness. FIG. 9 shows an example of a plate member 4 formed from a single metal plate. In the plate member 4 of FIG. 9, the peripheral wall 41 is perpendicular to the plate body 40. The plate member 4 having the plate body 40 and the peripheral wall 41 may be formed by casting or forging.

[0038] The plate member 4 may be formed by joining multiple members together. For example, the plate member 4 may be formed by joining a frame-shaped, flat, first member and a cylindrical second member together. In this case, the flat, first member forms the plate main body 40, and the cylindrical second member forms the peripheral wall 41. The multiple members that form the plate member 4 are joined together by, for example, welding or adhesive.

[0039] As described above, the wire harness 1 of this embodiment includes the flexible printed circuit board 3, the chip fuse 6, the plate member 4, and the potting material 5. The chip fuse 6 is mounted on the flexible printed circuit board 3. The plate member 4 includes a frame-shaped, flat plate body 40 and a cylindrical peripheral wall 41. The peripheral wall 41 protrudes from the plate body 40 in the thickness direction T of the plate body 40.

[0040] The plate body 40 is fixed to the flexible printed circuit board 3 so as to surround the chip fuses 6 with the peripheral wall 41. The potting material 5 is filled into the space 4s surrounded by the peripheral wall 41 to cover the chip fuses 6. In the wire harness 1 of this embodiment, the thickness of the plate body 40 can be reduced, thereby making it possible to reduce the weight of the plate member 4.

[0041] The plate member 4 of this embodiment is made of a metal plate. The peripheral wall 41 is formed by burring the metal plate. With this configuration, it is possible to make the entire plate member 4 thin-walled.

[0042] The flexible printed circuit board 3 of this embodiment has a trunk line 30 and branch portions 31. The branch portions 31 branch off from the trunk line 30 and are connected to the bus bar 10. The chip fuses 6 are mounted on the branch portions 31. The plate body 40 is fixed to the branch portions 31 so as to surround the chip fuses 6 with a peripheral wall 41. The weight reduction of the plate member 4 reduces the load on the branch portions 31.

[0043] The plate member 4 of this embodiment is a member made of a conductive metal, and electrically connects the chip fuse 6 and the bus bar 10. By forming the space 4s for the potting material 5 using the terminal member, it is possible to reduce the number of parts.

[0044] The position where the chip fuse 6 is mounted is not limited to the branch portion 31. The chip fuse 6 may be mounted on the main line 30. The number of chip fuses 6 housed in the space portion 4s is not limited to one. The plate body 40 of the plate member 4 may be fixed to the flexible printed circuit board 3 so that the peripheral wall 41 surrounds the plurality of chip fuses 6. In this case, the potting material 5 can be filled into the space portion 4s surrounded by the peripheral wall 41 to cover the plurality of chip fuses 6.

[0045] The contents disclosed in the above embodiments can be implemented in appropriate combinations. [Explanation of symbols]

[0046] 1: Wire harness 2: Case, 3: Flexible printed circuit board 4: Plate member, 4s: Space portion 5: Potting material, 6: Chip fuse, 9: Detection wire 10: Bus bar 11: first pad, 12: second pad, 13: third pad, 14: connecting wire 30: trunk line, 31: branch, 32: mounting area 40: Plate body, 40a: First surface, 40b: Second surface 41: peripheral wall, 41a: tip surface, 42: inner wall surface, 43: outer wall surface 100: Battery pack, 110: Battery module, 120: Battery cell 130: Monitoring device 200: Busbar module AR: Array Direction H1: Depth of potting layer, H2: Height of chip fuse X: Longitudinal direction, Y: Width direction, T: Thickness direction

Claims

1. A flexible printed circuit board; a chip fuse mounted on the flexible printed circuit board; a plate member including a flat plate body having a frame shape and a cylindrical peripheral wall protruding from the plate body in a thickness direction of the plate body; A potting agent; Equipped with the plate body is fixed to the flexible printed circuit board so that the peripheral wall surrounds the chip fuse; The potting material is filled in the space surrounded by the peripheral wall to cover the chip fuse. A wire harness characterized by:

2. the plate member is formed of a metal plate, The peripheral wall is formed by burring the metal plate. The wire harness according to claim 1 .

3. the flexible printed circuit board has a trunk line and a branch portion branching from the trunk line and connected to a bus bar, The chip fuse is mounted on the branch portion, The plate body is fixed to the branch portion so that the peripheral wall surrounds the chip fuse. The wire harness according to claim 1 .

4. The plate member is a member formed of a conductive metal and electrically connects the chip fuse and the bus bar. The wire harness according to claim 1 .

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