Flat wire connection structure

Abstract

To provide a flat wire connection structure that can further reduce external electromagnetic noise influence on a flat wire including a signal line.SOLUTION: A flat wire 11 comprises at least one conductor unit U1 including at least one signal line S1, S2 which are electrically connected to each signal circuit 13S,14S of two electronic devices 13, 14 at both ends and a pair of ground lines G1, G2 which are arranged on both sides with the signal line S1, S2 interposed therebetween and extend in the same direction as the signal line S1, S2. Both of one ends G1e1, G2e1 of the pair of ground lines G1, G2 are electrically connected to a ground circuit 13G of one electronic device 13, and both or any one of the other ends G1e2, G2e2 is not electrically connected to a ground circuit 14G of the other electronic device 14.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a connection structure for a flat electric wire, typically a flat cable. [Background technology]

[0002] Conventionally, flat electric wires have been used for electrical connections in vehicles. For example, a steering wheel mounted on an automobile rotates clockwise and counterclockwise from a neutral position, so a rotary connector device is used to electrically connect the steering wheel and the vehicle, and flat electric wires are used as wiring to connect a fixed body and a rotating body in the rotary connector device. In addition, flat electric wires are suitably used to electrically connect movable objects and fixed objects, such as between a sliding door and a vehicle, or between a sliding seat and a vehicle.

[0003] Flat electric wires include FPC (flexible printed circuit) and FFC (flexible flat cable), but so-called flat cables are more widely used due to their ease of handling, reliability of the connector, and cost. In the following, when we simply say "flat cable," it is meant to include both FPC and FFC unless otherwise specified.

[0004] Meanwhile, in vehicles, many electronic devices such as electrical equipment and vehicle control devices are installed for various purposes, and it is necessary to connect the electronic devices with signal lines in order to send various signals to these electronic devices. In order to make the flat cable including this signal line noise resistant, a shielded flat cable is used in which a pair of ground lines are arranged on both sides of the signal line and extend in the same direction as the signal line (for example, see Patent Document 1 and Patent Document 2).

[0005] In such a shielded flat cable, the signal line is sandwiched between a pair of ground wires, which makes it possible to prevent the signal line from being affected by external electromagnetic noise. However, since the current flowing through the signal line is very small, there is a concern that even small noise may have an effect, so further noise reduction measures are desired for the flat cable. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] WO2009 / 130859 [Patent Document 2] JP 2013-80624 A Summary of the Invention [Problem to be solved by the invention]

[0007] An object of the present invention is to provide a connection structure for flat electric wires that can further reduce the influence of external electromagnetic noise on flat electric wires including signal wires. [Means for solving the problem]

[0008] The above object can be achieved by the following aspect of the present invention. That is, a flat electric wire connection structure according to one aspect of the present invention is a flat electric wire connection structure for electrically connecting two electronic devices, comprising: the flat electric wire includes at least one conductor unit including at least one signal line electrically connected at both ends to signal circuits of the two electronic devices, and a pair of ground lines arranged on both sides of the signal line and extending in the same direction as the signal line; One end of each of the pair of ground wires is electrically connected to a ground circuit of one of the two electronic devices, and neither or neither of the other ends of the pair of ground wires is electrically connected to the ground circuit of the other of the two electronic devices.

[0009] In the above aspect of the present invention, in the conductor unit, two or more of the signal lines may be arranged in the arrangement direction.

[0010] In the above aspect of the present invention, in the conductor unit, one or more general electrical wires may extend between the pair of ground wires in the same direction as the signal wires.

[0011] In one aspect of the present invention, the flat electric wire may include a shielding material arranged in one or both of a direction intersecting with the arrangement direction and the extension direction of the signal line and the ground line in the conductor unit. In this case, when a pair of the shielding materials are arranged in both of a direction intersecting with the arrangement direction and the extension direction of the signal line and the ground line in the conductor unit, one end of the pair of shielding materials may be electrically connected to a ground circuit of one or the other of the two electronic devices, and one or neither of the other ends of the pair of shielding materials may be electrically connected to a ground circuit of the remaining of the two electronic devices.

[0012] In the above aspect of the present invention, the flat electric wire may be a flat cable. In this case, the flat electric wire constitutes a rotary connector device together with a fixed body and a rotating body, and is entirely or partially accommodated in an accommodation space between the fixed body and the rotating body, The two electronic devices may be a steering ECU for a vehicle and an ECU or combination switch device on the vehicle side.

[0013] Alternatively, the two electronic devices may be an ECU for a vehicle sliding door and an ECU on the vehicle side. Effect of the Invention

[0014] According to the above aspect of the present invention, it is possible to provide a connection structure for flat electric wires that can further reduce the influence of external electromagnetic noise on flat electric wires including signal wires. [Brief description of the drawings]

[0015] [Figure 1] 1 is a schematic diagram showing a connection structure of a flat electric wire according to a first embodiment which is an exemplary aspect of the present invention. [Diagram 2] 4 is a cross-sectional view taken along the extension direction (longitudinal direction) of the flat cable (flat electric wire) in the first embodiment, and taken along the line BB in FIG. [Diagram 3] 3 is a cross-sectional view taken along a direction (short direction) perpendicular to the extension direction of the flat cable (flat electric wire) in the first embodiment, and taken along the line AA in FIG. 2. FIG. [Figure 4] 1 is a schematic configuration diagram showing a specific example 1 of a connection structure for a flat electric wire according to a first embodiment. [Diagram 5] 4 is a schematic configuration diagram showing a specific example 2 of the connection structure of the flat electric wire according to the first embodiment. FIG. [Figure 6] 3 is a schematic configuration diagram showing a specific example 3 of the connection structure of the flat electric wire according to the first embodiment. FIG. [Figure 7] FIG. 4 is a schematic configuration diagram showing a specific example 4 of the connection structure of the flat electric wire according to the first embodiment. [Figure 8] FIG. 2 is a schematic diagram showing a connection structure of a flat electric wire according to a second embodiment which is an exemplary aspect of the present invention. [Figure 9] FIG. 4 is a schematic diagram showing a connection structure of a flat electric wire according to a third embodiment which is an exemplary aspect of the present invention. [Figure 10] FIG. 11 is a schematic diagram showing a connection structure of a flat electric wire according to a fourth embodiment which is an exemplary aspect of the present invention. [Figure 11] FIG. 13 is a schematic diagram showing a connection structure of a flat electric wire according to a fifth embodiment which is an exemplary aspect of the present invention. [Figure 12]FIG. 13 is a schematic diagram showing a connection structure of a flat electric wire according to a sixth embodiment which is an exemplary aspect of the present invention. [Figure 13] FIG. 13 is a schematic diagram showing a connection structure of a flat electric wire according to a seventh embodiment which is an exemplary aspect of the present invention. [Figure 14] 13 is a cross-sectional view taken along a direction perpendicular to the extension direction (short direction) of a flat cable (flat electric wire) in a seventh embodiment. FIG. [Figure 15] FIG. 13 is a schematic diagram showing a connection structure of a flat electric wire according to an eighth embodiment which is an exemplary aspect of the present invention. [Figure 16] 13 is a cross-sectional view taken along a direction perpendicular to the extension direction (short direction) of a flat cable (flat electric wire) in an eighth embodiment. FIG. [Figure 17] FIG. 13 is a schematic diagram showing a connection structure of a flat electric wire according to a ninth embodiment which is an exemplary aspect of the present invention. [Figure 18] 13 is a cross-sectional view taken along a direction perpendicular to the extension direction (short direction) of a flat cable (flat electric wire) in a ninth embodiment. FIG. [Figure 19] 21 is a cross-sectional view taken along the extension direction (longitudinal direction) of a flat cable (flat electric wire) according to a modified example applicable to the first embodiment, and is a cross-sectional view taken along the line DD in FIG. 20. FIG. [Figure 20] 20 is a cross-sectional view taken along a direction perpendicular to the extension direction (short direction) of a flat cable (flat electric wire) according to a modified example applicable to the first embodiment, and taken along the CC cross section of FIG. 19. FIG. [Figure 21] 11 is a cross-sectional view taken along the extension direction (longitudinal direction) of a flat cable (flat electric wire) according to another modified example applicable to the first embodiment. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, flat electric wire connection structures according to nine embodiments, which are illustrative aspects of the present invention, will be described with reference to the drawings.

[0017] [First embodiment] Fig. 1 is a schematic diagram showing a connection structure 1 for a flat electric wire according to a first embodiment. The connection structure 1 is an example of a connection structure for a flat electric wire (reference numeral 11) that electrically connects two electronic devices (reference numerals 13 and 14). Note that Fig. 1 shows each member in a schematic manner so that only the layout of the wiring of the flat electric wire can be seen.

[0018] In this embodiment, the two electronic devices are specifically a first electronic device 13 which is a combination switch device on the vehicle side, and a second electronic device 14 which is an ECU (Electronic Control Unit) of a steering wheel for the vehicle. The second electronic device 14 is disposed in a movable area of ​​the steering wheel, and is connected to the first electronic device 13 on the vehicle side via the rotary connector device 12. In FIG. 1, the outer shape of the rotary connector device 12 is represented by a rectangle with rounded corners.

[0019] The rotary connector device 12 is mainly composed of a flat cable 11, which is a flat electric wire, a fixed body, and a rotating body. The rotary connector device 12 is also called an SRC (Steering Roll Connector), and is a device that is mounted on an automobile and electrically connects a first electronic device 13 provided on the fixed body side and a second electronic device 14 provided on the rotating body side.

[0020] In the rotary connector device 12, the fixed body is fixed to the vehicle body and does not rotate in response to rotation of a steering wheel (not shown). On the other hand, the rotating body rotates in response to rotation of a steering wheel (not shown). All or part of the flat cable 11, which is a flat electric wire, is accommodated in the accommodation space between the fixed body and the rotating body. The steering wheel is mounted on the vehicle (not shown) so as to be rotatable.

[0021] Here, "the entire flat cable 11 is accommodated" refers to a state in which the entire flat cable 11 is accommodated in the accommodation space, with only the terminals, bus bars, etc. protruding outside the accommodation space and connected to external electronic devices (reference numerals 13, 14). Additionally, "a portion of the flat cable 11 is accommodated" refers to a state in which an end of the flat cable 11 protrudes outside the accommodation space.

[0022] Fig. 2 is a cross-sectional view taken in the extension direction (longitudinal direction) of flat cable 11, and Fig. 3 is a cross-sectional view taken in a direction perpendicular to the extension direction (short direction). Fig. 2 is a cross-sectional view taken along the line BB of Fig. 3, and Fig. 3 is a cross-sectional view taken along the line AA of Fig. 2. In Figs. 2 and 3, coordinate axis x indicates the extension direction (longitudinal direction) of flat cable 11, coordinate axis y indicates the arrangement direction (short direction) of flat cable 11, and coordinate axis z indicates the thickness direction (up-down direction) of flat cable 11.

[0023] 2 and 3, the flat cable 11 includes one conductor unit U1 including two signal lines S1 and S2 arranged in the arrangement direction (the y-axis direction) and a pair of ground lines G1 and G2. The signal lines S1 and S2 and the ground lines G1 and G2 are copper foil conductors. The circumferential surface of the flat cable 11 in the extension direction (longitudinal direction, the x-axis direction) is laminated with an insulating resin film R.

[0024] In the conductor unit U1, a pair of ground wires G1, G2 are arranged on either side of the signal lines S1, S2 (on either side in the y coordinate direction) and extend in the same direction as the signal lines S1, S2 (x coordinate direction).

[0025] As shown in FIG. 1, one end S1 of two signal lines S1 and S2 e1 ,S2 e1 1 and 2 are connected to a signal circuit 13 such as a CAN (Controller Area Network) of a first electronic device (one electronic device) 13. S On the other hand, the other ends S1 of the two signal lines S1 and S2 are electrically connected to e2 ,S2 e2 1 and 2 are connected to a signal circuit 14 such as a CAN of a second electronic device (another electronic device) 14. S Therefore, communication between the first electronic device 13 and the second electronic device 14 is performed via the two signal lines S1 and S2.

[0026] In this embodiment, one end G1 of the pair of ground lines G1 and G2 e1 ,G2 e1 1 and 2 are connected to the ground circuit 13 of the first electronic device (one electronic device) 13. G On the other hand, the other end G1 of the pair of ground lines G1 and G2 is electrically connected to e2 ,G2 e2 is the end G1 e2 However, the ground circuit 14 of the second electronic device (other electronic device) 14 G Although it is electrically connected to the end G2 e2 14 is the ground circuit G is not electrically connected to

[0027] Ground circuit 13 of first electronic device 13 G is grounded to, for example, the chassis of the vehicle (ground wiring 13 GG ). Therefore, the ground circuit 13 G , ground lines G1, G2 and ground circuit 14 G The potentials of the ends G2 and G3 are the same and are at the reference potential. e2 14 is the ground circuit G If we assume that the ground circuit is electrically connected to G -Ground wire G1 -Ground circuit 13 G -Ground wire G2-Ground circuit 14 G A loop (hereinafter referred to as a "ground loop") is formed that is electrically connected in the order of . When a ground loop is formed, the ground loop acts like an antenna and may receive weak electromagnetic waves from outside. The received weak electromagnetic waves may affect the weak signal current flowing through the signal lines S1 and S2 surrounded by the ground loop, raising the concern that noise may be introduced into the signal current.

[0028] However, in this embodiment, the end G2 e2 14 is the ground circuit GSince the virtual line vl1 is not electrically connected to the signal lines S1 and S2, there is no electrical connection of the virtual line vl1. Therefore, a ground loop is not formed, and the signal lines S1 and S2 are not surrounded by a ground loop. Therefore, according to this embodiment, the concern that the ground loop may pick up external electromagnetic noise is eliminated, and the influence of external electromagnetic noise on the flat cable 11 including the signal lines S1 and S2 can be further reduced.

[0029] The connection state of the actual flat cable (flat electric wire) 11 in this embodiment will be described with four specific examples (specific examples 1 to 4). Fig. 4 is a schematic configuration diagram showing a specific example 1 of the connection structure 1 of a flat electric wire according to the first embodiment. The connection structure 1 itself is similar to that shown in Fig. 1 (the same applies to Figs. 5 to 7).

[0030] As shown in FIG. 4, in the specific example 1, the first electronic device 13 and the second electronic device 14 each have a signal circuit 13 such as a CAN (Controller Area Network) on one board. S ,14 S and ground circuit 13 G ,14 G The flat cable 11 is configured by wiring the signal lines S1 and S2, both ends of the ground line G1, and the other end G2 of the ground line G2. e1 The terminal includes a bus bar 11 having a male terminal-shaped tip. BB1 ,11 BB2 is connected to the other end G2 of the ground line G2. e2 A bus bar BL that does not have a male terminal-shaped tip is connected to the terminals.

[0031] On the other hand, the first electronic device 13 and the second electronic device 14 are provided with a signal circuit 13. S ,14 S and ground circuit 13 G ,14 G Female terminal 13 electrically connected to FT ,14 FT The busbar 11 is provided. BB1 ,11BB2 The male terminals at the tip are female terminals 13 FT ,14 FT , and through this, the signal lines S1, S2 and the ground line G1 are connected to the signal circuit 13 S ,14 S and ground circuit 14 G On the other hand, the end G2 of the ground line G2 is electrically connected to e2 The bus bar BL connected to the ground circuit 14 does not protrude. G is not electrically connected to

[0032] As described above, in the first specific example, the end G2 of the ground line G2 that is not electrically connected e2 In contrast, concrete example 2 is an example configured so that the electronic device side is not electrically connected to the ground circuit. FIG. 5 is a schematic diagram showing a specific example 2 of the flat electric wire connection structure 1 according to the first embodiment.

[0033] As shown in FIG. 5, in the second specific example, the signal lines S1 and S2, the ground lines G1 and G2, and the signal circuit 13 S ,14 S and ground circuit 13 G ,14 G The electrical connection structure with the ground line G2 is the same as that of the example 1. In the example 2, the (other) end G2 of the ground line G2 e2 The tip of the bus bar 11 is also shaped like a male terminal. BB2 The second electronic device 14 is also connected to the bus bar 11. BB2 Corresponding female terminal 14 FT is provided.

[0034] However, on the board of the second electronic device 14, the female terminal 14 FT Electrically connected wiring (land) 14 L 14 Ground Circuit G Therefore, the end G2 of the ground line G2 e2 14 Ground Circuit G is not electrically connected to

[0035] Next, the signal lines S1 and S2, the ground lines G1 and G2, and the signal circuit 14 S and ground circuit 14 G A specific example 3 in which the specific connection configuration of and is different from that of the specific example 1 will be described. FIG. 6 is a schematic diagram showing a specific example 3 of the flat electric wire connection structure 1 according to the first embodiment.

[0036] As shown in FIG. 6, in the third specific example, the signal lines S1 and S2, the ground lines G1 and G2, and the signal circuit 13 S ,14 S and ground circuit 13 G ,14 G The electrical connection structure with the ground line G2 is the same as that of the specific examples 1 and 2. In the specific example 3, the end G2 of the ground line G2 that is not electrically connected to each other is e2 and ground circuit 14 G The specific connection configuration is also the same as in Example 1. In Example 3, the signal lines S1 and S2 and the ground line G1 and the signal circuit 14 S and ground circuit 14 G The electrical connection structure is different.

[0037] The second electronic device 14 includes a signal circuit 14 S and ground circuit 14 G Busbar 14 electrically connected to BB The ends S1 of the signal lines S1 and S2 are provided. e2 ,S2 e2 and the end G1 of the ground line G1 e2 Busbar 11 connected to BB2 The male terminal at the tip is mated to the female terminal 15 FT are not fixed to the second electronic device 14 and are independent of each other. BB 15 FT and short wire harness 15 SW / H are electrically connected via

[0038] The configuration of the third example can be suitably employed when the end of the flat cable 11 on the rotating body side of the rotary connector device 12 is slightly separated from the second electronic device 14 such as a steering ECU.

[0039] Finally, a fourth specific example will be described in which the first electronic device 13 is far away from the end of the flat cable 11 on the fixed body side of the rotary connector device 12. Fig. 7 is a schematic diagram showing a specific example 4 of the flat electric wire connection structure 1 according to the first embodiment. In Fig. 7, the first electronic device 13 located at a distance is not shown in the drawing.

[0040] As shown in FIG. 7, in the fourth specific example, the signal lines S1 and S2, the ground lines G1 and G2, and the signal circuit 14 S and ground circuit 14 G The specific connection configuration between the signal lines S1 and S2 and the ground lines G1 and G2 and the signal circuit 13 is the same as that of the second embodiment. Although the first electronic device 13 is not shown in the drawing, the signal lines S1 and S2 and the ground lines G1 and G2 are also connected to the signal circuit 13 in the fourth embodiment. S ,14 S and ground circuit 13 G ,14 G The electrical connection structure is the same as in Examples 1 to 3.

[0041] In the specific example 4, (one) end S1 of the signal lines S1 and S2 in the flat cable 11 e1 ,S2 e1 In the same manner as in the concrete examples 1 to 3, the tip of the bus bar 11S is formed into a male terminal shape. BB1 is connected to busbar 11S BB1 The male terminal at the tip is connected to the female terminal 16S FT is not fixed to the first electronic device 13 and is connected to the wire harness 16S W / H Connected to wire harness 16S W / H The signal circuit 14 of the first electronic device 13 located at a remote location in the vehicle S is electrically connected to

[0042] On the other hand, in the specific example 4, (one) end G1 of the ground lines G1 and G2 in the flat cable 11 e1 ,G2 e1 Similarly to the concrete examples 1 to 3, the tip of the bus bar 11G is formed into a male terminal shape. BB1 is connected to busbar 11G. BB1 The male terminal at the tip is connected to the female terminal 16G FT is not fixed to the first electronic device 13 and is connected to the wire harness 16G. W / H Connected to Wire Harness 16G W / H The ground circuit 13 of the first electronic device 13 located at a remote location in the vehicle is G is electrically connected to

[0043] As can be seen from the above explanations of specific examples 1 to 4, the signal lines S1 and S2 and the ground lines G1 and G2 in the flat cable 11 and the signal circuit 13 in the first electronic device 13 and the second electronic device 14 are S ,14 S and ground circuit 13 G ,14 G The connection may be via a bus bar or terminal, or may be via a wire harness (including other flat cables), etc. As described above, even if these other members are used, as long as the electrical connection between the signal line or ground line and the electronic device is ensured, this corresponds to the state of "electrically connecting" or "electrically connected" as defined in the present invention.

[0044] Although the connection state of the actual flat cable (flat electric wire) 11 in the first embodiment has been described above using four specific examples, the specific connection configuration is not limited to these, and there is no problem as long as it is equivalent to the connection structure according to the first embodiment as an electric circuit. For example, a configuration that combines two or more of the characteristic configurations of each of the above specific examples 1 to 4 may be used. The characteristic configurations of each of these specific examples 1 to 4 can be suitably applied to all of the embodiments described later, and like this embodiment, it is not limited to these configurations.

[0045] [Second embodiment] Fig. 8 is a schematic diagram showing a connection structure 2 of a flat electric wire according to a second embodiment. The connection structure 2 is an example of a connection structure of a flat electric wire (reference numeral 11) that electrically connects two electronic devices (reference numerals 13 and 14). Note that Fig. 8 shows each member in a schematic manner so that only the layout of the wiring of the flat electric wire can be seen.

[0046] 8 showing the connection structure 2 according to the present embodiment, the same reference numerals as those in the first embodiment are used for the components having the same or similar configurations as those in the connection structure 1 according to the first embodiment, and the description of the common configurations of the components will be omitted. The following mainly describes the differences from the first embodiment.

[0047] In this embodiment, one end G1 of the pair of ground lines G1 and G2 e2 ,G2 e2 1 and 2 are connected to the ground circuit 14 of the second electronic device (first electronic device) 14. G The other end G1 of the pair of ground lines G1 and G2 is electrically connected to e1 ,G2 e1 is the end G2 e1 However, the ground circuit 13 of the first electronic device (other electronic device) 13 G Although it is electrically connected to the end G1 e1 13 is the ground circuit G That is, in this embodiment, the end of the flat cable 11 that is not electrically connected to the ground circuit of the electronic device is on the opposite side (the first electronic device 13 side).

[0048] In this embodiment, the ground circuit 13 of the first electronic device 13 G is grounded to, for example, the chassis of the vehicle (ground wiring 13 GG ). Therefore, the ground circuit 13 G , ground lines G1, G2 and ground circuit 14 G At this time, the potentials of the ends G1 and G2 are aligned and set to the reference potential. e1 Ground circuit 13G If we assume that the ground circuit is electrically connected to G -Ground wire G1 -Ground circuit 13 G -Ground wire G2 -Ground circuit 14 G A ground loop is formed that is electrically connected in the order of

[0049] However, in this embodiment, the end G1 e1 Ground circuit 13 G Since the virtual line vl2 is not electrically connected to the signal lines S1 and S2, there is no electrical connection of the virtual line vl2. Therefore, a ground loop is not formed, and the signal lines S1 and S2 are not surrounded by a ground loop. Therefore, according to this embodiment, the concern that the ground loop may pick up external electromagnetic noise is eliminated, and the influence of external noise on the flat cable 11 including the signal lines S1 and S2 can be further reduced.

[0050] [Third embodiment] Fig. 9 is a schematic diagram showing a connection structure 3 of a flat electric wire according to a third embodiment. The connection structure 3 is an example of a connection structure of a flat electric wire (reference numeral 11) that electrically connects two electronic devices (reference numerals 13 and 14). Note that Fig. 9 shows each member in a schematic manner so that only the layout of the wiring of the flat electric wire can be seen.

[0051] 9 showing the connection structure 3 according to the present embodiment, the same reference numerals as those in the first embodiment are used for the components having the same or similar configurations as those in the connection structure 1 according to the first embodiment, and the description of the common configurations of the components will be omitted. The following mainly describes the differences from the first embodiment.

[0052] In this embodiment, the other end G1 of the pair of ground lines G1 and G2 e2 ,G2 e2 is the end G2 e2 Not only the end G1 e2 Ground circuit 14 GThat is, in this embodiment, the other end G1 of the pair of ground lines G1 and G2 is not electrically connected to the e2 ,G2 e2 In either case, the ground circuit 14 of the second electronic device (other electronic device) 14 G is not electrically connected to

[0053] In this embodiment, the ground circuit 14 of the second electronic device 14 G However, apart from the case of the connection structure 1, the ground wire 14 is grounded to, for example, the chassis of the vehicle. GG ). Ground Wire 14 GG This can be achieved, for example, by using an electric wire other than the conductor unit U1 in the flat cable 11 (i.e., an electric wire that is not sandwiched between the pair of ground wires G1, G2), by routing a separate cable, or by using the steering shaft as a conductor.

[0054] In this embodiment, the other end G1 of the pair of ground lines G1 and G2 e2 ,G2 e2 are completely open, no ground loop is formed, and the signal lines S1 and S2 are not surrounded by a ground loop. Therefore, according to this embodiment, the concern that the ground loop may pick up external electromagnetic noise is eliminated, and the influence of external electromagnetic noise on the flat cable 11 including the signal lines S1 and S2 can be further reduced.

[0055] In this embodiment, the ground circuit 14 of the second electronic device 14 G Ground wire 14 for grounding GG In the above embodiment, it is necessary to separately prepare a second electrode, but since this is not necessary, the first and second embodiments are advantageous in terms of economy, manufacturability, and ease of design.

[0056] [Fourth embodiment] Fig. 10 is a schematic diagram showing a connection structure 4 of a flat electric wire according to a fourth embodiment. The connection structure 4 is an example of a connection structure of a flat electric wire (reference numeral 41) that electrically connects two electronic devices (reference numerals 13 and 14). Note that Fig. 10 shows each member in a schematic manner so that only the layout of the wiring of the flat electric wire can be seen.

[0057] 10 showing the connection structure 4 according to the present embodiment, the same reference numerals as those in the first embodiment are used for the components having the same or similar configurations as those in the connection structure 1 according to the first embodiment, and the description of the common configurations of the components will be omitted. The following mainly describes the differences from the first embodiment.

[0058] In this embodiment, one conductor unit U1' in flat cable 41 includes only one signal line S1, which differs from the first embodiment in that one conductor unit U1 includes two signal lines S1 and S2. Other configurations are common to this embodiment and the first embodiment.

[0059] In this embodiment, similarly to the first embodiment, the other end G1 of the pair of ground lines G1 and G2 e2 ,G2 e2 Of these, end G2 e2 14 is the ground circuit G Therefore, no ground loop is formed in the conductor unit U1, and the signal line S1 is not surrounded by a ground loop. Therefore, according to this embodiment, the concern that external electromagnetic noise may be picked up by a ground loop is eliminated, and the influence of external electromagnetic noise on the flat cable 41 including the signal line S1 can be further reduced.

[0060] [Fifth embodiment] Fig. 11 is a schematic diagram showing a connection structure 5 of a flat electric wire according to a fifth embodiment. The connection structure 5 is an example of a connection structure of a flat electric wire (reference numeral 41) that electrically connects two electronic devices (reference numerals 13 and 14). Note that Fig. 11 shows each member in a schematic manner so that only the layout of the wiring of the flat electric wire can be seen.

[0061] 11 showing the connection structure 5 according to the present embodiment, each member having a configuration similar to or similar to the connection structure 1 according to the first embodiment, the connection structure 3 according to the third embodiment, or the connection structure 4 according to the fourth embodiment is given the same reference numeral as in the first embodiment, the third embodiment, or the fourth embodiment, and a description of the common configuration of each member will be omitted. Below, differences from the first embodiment will be mainly described.

[0062] In this embodiment, as in the fourth embodiment, a flat cable 41 is used in which one conductor unit U1′ includes only one signal line S1. Also, in this embodiment, as in the third embodiment, the other end G1 of the pair of ground lines G1 and G2 is e2 ,G2 e2 But end G2 e2 Not only the end G1 e2 Ground circuit 14 G In this embodiment, similarly to the third embodiment, the ground circuit 14 of the second electronic device 14 is not electrically connected to the G However, apart from the case of the connection structure 1, the ground wire 14 is grounded to, for example, the chassis of the vehicle. GG ).

[0063] In this embodiment, the other end G1 of the pair of ground lines G1 and G2 e2 ,G2 e2is completely open, no ground loop is formed, and the signal line S1 is not surrounded by a ground loop. Therefore, according to this embodiment, the concern that a ground loop may pick up external electromagnetic noise is eliminated, and the influence of external electromagnetic noise on the flat cable 41 including the signal line S1 can be further reduced.

[0064] [Sixth embodiment] Fig. 12 is a schematic diagram showing a connection structure 6 of a flat electric wire according to a sixth embodiment. The connection structure 6 is an example of a connection structure of a flat electric wire (reference numeral 61) that electrically connects two electronic devices (reference numerals 13 and 14). Note that Fig. 12 shows each member in a schematic manner so that only the layout of the wiring of the flat electric wire can be seen.

[0065] 12 showing the connection structure 6 according to the present embodiment, the same reference numerals as those in the first embodiment are used for the components having the same or similar configurations as those in the connection structure 1 according to the first embodiment, and the description of the common configurations of the components will be omitted. The following mainly describes the differences from the first embodiment.

[0066] In this embodiment, a ground wire G0 is arranged parallel to the ground wire G1 outside the ground wire G1 side of the pair of ground wires G1 and G2. That is, the flat cable 61 in this embodiment differs from the flat cable 11 in the first embodiment in that the ground wire G0 is additionally arranged. One end G0 of the ground wire G0 e1 The ground circuit 13 of the first electronic device 13 G and the other end G0 e2 The ground circuit 14 of the second electronic device 14 G is electrically connected to

[0067] As shown in FIG. 12, in this embodiment, the ground circuit 14 G -Ground wire G0-Ground circuit 13 G -Ground wire G1 -Ground circuit 14 GA loop is formed in which the two signal lines S1 and S2 are electrically connected in this order. However, this loop is formed via a ground line G0 that is unrelated to the conductor unit U1, which is made up of two signal lines S1 and S2 and a pair of ground lines G1 and G2. Therefore, the loop does not surround the signal lines S1 and S2.

[0068] In this embodiment, similarly to the first embodiment, the other end G1 of the pair of ground lines G1 and G2 e2 ,G2 e2 Of these, end G2 e2 14 is the ground circuit G conductor unit U1, the signal lines S1 and S2 are not electrically connected to each other. Therefore, no ground loop is formed in the conductor unit U1, and the signal lines S1 and S2 are not surrounded by a ground loop. Therefore, according to this embodiment, the concern that external electromagnetic noise may be picked up by a ground loop is eliminated, and the influence of external electromagnetic noise on the flat cable 61 including the signal lines S1 and S2 can be further reduced.

[0069] [Seventh embodiment] Fig. 13 is a schematic diagram showing a flat electric wire connection structure 7 according to a seventh embodiment. The connection structure 7 is an example of a connection structure for a flat electric wire (reference numeral 71) that electrically connects two electronic devices (reference numerals 13 and 14). Note that Fig. 13 shows each component diagrammatically so that only the layout of the flat electric wire can be seen. Fig. 14 is a cross-sectional view taken in a direction perpendicular to the extension direction (short direction) of a flat cable (flat electric wire) 71 in this embodiment.

[0070] 13 showing the connection structure 7 according to this embodiment and in Fig. 14 showing the flat cable 71, the same reference numerals as in the first embodiment are used to designate the same or similar components as those in the connection structure 1 and flat cable 11 according to the first embodiment, and a description of the common components will be omitted. Below, differences from the first embodiment will be mainly described.

[0071] 13 and 14, in this embodiment, another conductor unit U2 consisting of two signal lines S3, S4 and a pair of ground lines G3, G4 is arranged outside the ground line G2 side of the conductor unit U1 and in parallel to the conductor unit U1. That is, this embodiment is configured to have two "conductor units consisting of at least one signal line and a pair of ground lines arranged on both sides of the signal line and extending in the same direction as the signal line."

[0072] As shown in FIG. 13, in the conductor unit U2, one end S3 of the two signal lines S3 and S4 is e1 ,S4 e1 1 and 2 are the signal circuits 13 of the first electronic device (one electronic device) 13. S On the other hand, the other ends S3 of the two signal lines S3 and S4 are electrically connected to e2 ,S4 e2 , and the signal circuit 14 of the second electronic device (other electronic device) 14 S Therefore, communication between the first electronic device 13 and the second electronic device 14 is performed via the four signal lines S1, S2, S3, and S4.

[0073] As shown in FIG. 13, in the conductor unit U2, one end G3 of the pair of ground wires G3 and G4 e1 ,G4 e1 1 and 2 are connected to the ground circuit 13 of the first electronic device (one electronic device) 13. G On the other hand, the other end G3 of the pair of ground lines G3 and G4 is electrically connected to e2 ,G4 e2 In either case, the ground circuit 14 of the second electronic device (other electronic device) 14 G is not electrically connected to

[0074] In this embodiment, the ground circuit 14 of the second electronic device 14 G is connected to the ground circuit 13 of the first electronic device 13 via the ground line G1 in the conductor unit U1. G Therefore, the ground circuit 14 of the second electronic device 14 is electrically connected to theG A ground wiring (reference numeral 14 in the third embodiment) for grounding the GG , see FIG. 9) is not required.

[0075] In this embodiment, similarly to the first embodiment, the other end G1 of the pair of ground lines G1 and G2 e2 ,G2 e2 Of these, end G2 e2 14 is the ground circuit G The other end G3 of the pair of ground lines G3 and G4 is not electrically connected to the e2 ,G4 e2 are completely open. Therefore, no ground loops are formed in either the conductor unit U1 or the conductor unit U2, and the signal lines S1, S2, S3, and S4 are not surrounded by ground loops. Therefore, according to this embodiment, the concern that external electromagnetic noise may be picked up by ground loops is eliminated, and the influence of external electromagnetic noise on the flat cable 71 including the signal lines S1, S2, S3, and S4 can be further reduced.

[0076] [Eighth embodiment] Fig. 15 is a schematic diagram showing a connection structure 8 of a flat electric wire according to an eighth embodiment. The connection structure 8 is an example of a connection structure of a flat electric wire (reference numeral 81) that electrically connects two electronic devices (reference numerals 13 and 14). Note that Fig. 15 shows each component diagrammatically so that only the wiring of the flat electric wire can be seen. Fig. 16 is a cross-sectional view taken in a direction perpendicular to the extension direction (short direction) of a flat cable (flat electric wire) 81 in this embodiment.

[0077] 15 showing a connection structure 8 according to this embodiment and in Fig. 16 showing a flat cable 81, the same reference numerals as in the first embodiment and the seventh embodiment are used to denote components having the same or similar configurations as the connection structure 1 and flat cable 11 according to the first embodiment, or the connection structure 7 and flat cable 71 according to the seventh embodiment, and a description of the common configurations of the components will be omitted. Below, differences from the first embodiment will be mainly described.

[0078] 15 and 16, in this embodiment, two signal lines S3, S4 and a ground line G4 are arranged in parallel to the conductor unit U1 outside the ground line G2 side of the conductor unit U1. As in the first embodiment, the conductor unit U1 is composed of two signal lines S1, S2 and a pair of ground lines G1, G2.

[0079] Furthermore, in this embodiment, the conductor unit U2' is composed of two signal lines S3, S4 and a pair of ground lines G2, G4, including the ground line G2, which is one of the components of the conductor unit U1. In other words, the ground line G2 is shared between the conductor unit U1 and the conductor unit U2'. In this manner, in an aspect of the present invention, a "conductor unit" may share a ground line with an adjacent conductor unit.

[0080] Therefore, like the seventh embodiment, this embodiment has a configuration including two "conductor units each consisting of at least one signal line and a pair of ground lines arranged on either side of the signal line and extending in the same direction as the signal line."

[0081] As shown in FIG. 15, in the conductor unit U2′, one end S3 of the two signal lines S3 and S4 is e1 ,S4 e1 1 and 2 are the signal circuits 13 of the first electronic device (one electronic device) 13. S On the other hand, the other ends S3 of the two signal lines S3 and S4 are electrically connected to e2 ,S4 e2 , and the signal circuit 14 of the second electronic device (other electronic device) 14S Therefore, communication between the first electronic device 13 and the second electronic device 14 is performed via the four signal lines S1, S2, S3, and S4.

[0082] As shown in FIG. 15, in the conductor unit U2′, one end G2 of the pair of ground wires G2 and G4 is e1 ,G4 e1 1 and 2 are connected to the ground circuit 13 of the first electronic device (one electronic device) 13. G On the other hand, the other end G2 of the pair of ground lines G2 and G4 is electrically connected to e2 ,G4 e2 In either case, the ground circuit 14 of the second electronic device (other electronic device) 14 G is not electrically connected to

[0083] In this embodiment, similarly to the seventh embodiment, the ground circuit 14 of the second electronic device 14 G is connected to the ground circuit 13 of the first electronic device 13 via the ground line G1 in the conductor unit U1. G Therefore, the ground circuit 14 of the second electronic device 14 is electrically connected to the G A ground wiring (reference numeral 14 in the third embodiment) for grounding the GG , see FIG. 9) is not required.

[0084] In this embodiment, similarly to the first embodiment, the other end G1 of the pair of ground lines G1 and G2 e2 ,G2 e2 Of these, end G2 e2 14 is the ground circuit G The other end G2 of the pair of ground lines G2 and G4 is not electrically connected to the e2 ,G4 e2are completely open. Therefore, no ground loops are formed in either the conductor unit U1 or the conductor unit U2', and the signal lines S1, S2, S3, and S4 are not surrounded by ground loops. Therefore, according to this embodiment, the concern that ground loops may pick up external electromagnetic noise is eliminated, and the influence of external electromagnetic noise on the flat cable 81 including the signal lines S1, S2, S3, and S4 can be further reduced.

[0085] [Ninth embodiment] Fig. 17 is a schematic diagram showing a connection structure 9 of a flat electric wire according to an eighth embodiment. The connection structure 9 is an example of a connection structure of a flat electric wire (reference numeral 91) that electrically connects two electronic devices (reference numerals 13 and 14). Note that Fig. 17 shows each component in a schematic manner so that only the wiring of the flat electric wire can be seen. Fig. 18 is a cross-sectional view taken in a direction perpendicular to the extension direction (short direction) of a flat cable (flat electric wire) 91 in this embodiment.

[0086] 17 showing the connection structure 9 according to this embodiment and in Fig. 18 showing the flat cable 91, the same reference numerals as in the first embodiment and the seventh embodiment are used to denote components similar to or similar to the connection structure 1 and flat cable 11 according to the first embodiment, or the connection structure 7 and flat cable 71 according to the seventh embodiment, and a description of the common configuration of each component will be omitted. Below, differences from the first embodiment will be mainly described.

[0087] In this embodiment, four signal lines S1, S2, S3, and S4 and two general electrical wirings A1 and A2 are arranged between a pair of ground lines G1 and G2 as shown in Figures 17 and 18. The general electrical wirings A1 and A2 extend in the same direction as the signal lines S1, S2, S3, and S4.

[0088] Here, "general electrical wiring" refers to general electrical wiring other than signal lines used for communication to exchange electrical signals and ground lines that maintain a constant reference potential within a circuit. Specific examples of "general electrical wiring" include power lines, various ON-OFF wiring, airbag activation wiring, volume control wiring, lighting wiring, etc.

[0089] As shown in FIG. 17, one end A1 of two general electric wirings A1 and A2 e1 ,A2 e1 13 of the first electronic device (one electronic device) 13 P On the other hand, the other end A1 of the two general electrical wirings A1 and A2 is electrically connected to e2 ,A2 e2 1 and 2 are electrical components 14 of a second electronic device (another electronic device) 14. P Therefore, the first electronic device 13 and the second electronic device 14 are electrically connected to each other via two general electric wirings A1 and A.

[0090] Electrical components 13 P and Electrical Components 14 P Examples of the combination include a volume control circuit and a volume control part (volume), an airbag activation power supply and an airbag activation device, an output terminal of a power supply circuit and a current input terminal of the electronic device 14, and the like.

[0091] In this embodiment, the electric component 13 P and electrical components 14 P are components of the first electronic device 13 and the second electronic device 14, the general electric wirings A1 and A2 may be electrically connected to electronic components or electronic circuits unrelated to these electronic devices.

[0092] In this embodiment, similarly to the first embodiment, the other end G1 of the pair of ground lines G1 and G2 e2 ,G2 e2 Of these, end G2 e2 14 is the ground circuit GTherefore, no ground loop is formed in the conductor unit U1'', and the signal lines S1, S2, S3, and S4 are not surrounded by a ground loop. Therefore, according to this embodiment, the concern that external electromagnetic noise will be picked up by a ground loop is eliminated, and the effect of external electromagnetic noise on the flat cable 91 including the signal lines S1, S2, S3, and S4 can be further reduced.

[0093] In this embodiment, general electrical wiring A1, A2 other than signal wires S1, S2, S3, S4 are arranged between a pair of ground wires G1, G2. The pair of ground wires G1, G2, the signal wires S1, S2, S3, S4, and the general electrical wiring A1, A2, a total of eight wires, constitute one conductor unit U1". In an aspect of the present invention, a "conductor unit" is sufficient if at least one signal wire is arranged between a pair of ground wires, and may include one or more general electrical wirings as in this embodiment.

[0094] In the present embodiment, the signal lines S1, S2, S3, S4 and the general electrical wirings A1, A2 are arranged between the pair of ground lines G1, G2 in such a manner that the two general electrical wirings A1, A2 are arranged in the center, and two signal lines S1, S2 and two signal lines S3, S4 are arranged on both sides of the two general electrical wirings A1, A2, but this is not limiting. For example, the general electrical wirings A1, A2 may be adjacent to the pair of ground lines G1, G2, or one or more signal lines may be arranged between the two general electrical wirings A1, A2.

[0095] In this embodiment, four signal lines S1, S2, S3, and S4 are arranged between a pair of ground lines G1 and G2. The number of signal lines may be four as in this embodiment, or may be less than three or more than five.

[0096] The nine embodiments described above are merely representative examples of the present invention, and the present invention is not limited to these embodiments. For example, in the above embodiments, examples are given in which one or two conductor units are provided, but the present invention is not limited to this, and the number of conductor units may be three or more.

[0097] In the seventh and eighth embodiments having two conductor units, the signal lines S1 and S2 and the signal lines S3 (or S2) and S4 belonging to each conductor unit are connected to the same signal circuit 13 of the first electronic device 13 at both ends. S and the signal circuit 14 of the second electronic device 14 S However, each conductor unit may be electrically connected to a different signal circuit.

[0098] Taking the seventh embodiment as an example, one end S1 of the signal lines S1 and S2 e1 ,S2 e1 are both signal circuits 13 of the first electronic device 13. S However, one end S3 of the signal lines S3 and S4 is electrically connected to the e1 ,S4 e1 may be electrically connected to a signal circuit of another electronic device different from the first electronic device 13, or may be electrically connected to a different signal circuit within the same first electronic device 13. e2 ,S4 e2 The same is true for the sides.

[0099] In the seventh and eighth embodiments including two conductor units, both of the two conductor units have the configuration of the present invention, and a configuration in which no ground loop occurs in the flat cable has been given as an example, but the present invention is not limited to this. That is, even if a ground loop occurs in any of the conductor units in a flat cable including multiple conductor units, the concern that electromagnetic noise will be picked up from the outside due to the ground loop can be eliminated by focusing on the conductor unit without a ground loop, and therefore the configuration of the present invention operates in the conductor unit, and the effect based on the present invention is achieved.

[0100] For example, there is little need to provide the configuration of the present invention in a conductor unit that includes only a signal line through which a signal that is not easily affected by external noise flows. Of course, it is more preferable for all conductor units in a flat cable to have the configuration of the present invention so that no ground loops occur, since this further reduces the effects of external electromagnetic noise in all signal lines.

[0101] Furthermore, in the nine embodiments described above, the two electronic devices electrically connected by the flat electric wire are an ECU for a steering wheel for a vehicle and a combination switch device on the vehicle side, but the present invention is not limited to this. For example, the electronic devices may be directly connected to the ECU on the vehicle side without going through the combination switch device on the vehicle side. Also, the two electronic devices electrically connected by the flat electric wire may be an ECU for a sliding door for a vehicle and an ECU on the vehicle side. In addition, the two electronic devices may be a combination of an ECU for a sliding seat for a vehicle and an ECU on the vehicle side, and the present invention can be suitably applied in this case as well.

[0102] In the nine embodiments described above, examples have been given in which flat cables are used in which the signal lines, ground lines, and general electrical wiring are copper foil conductors as shown in Figures 2, 3, 14, 16, and 18. However, the present invention is not limited to this. The present invention can also be suitably applied to flat cables in which the electrical wiring is, for example, so-called covered wires in which a metal core wire is covered with an insulating resin tube.

[0103] In the nine embodiments described above, as shown in Figures 2, 3, 14, 16 and 18, a flat cable is used in which a conductor unit consisting of a signal line, a ground line, etc. is laminated with a resin layer. However, the present invention is not limited to this, and a flat cable in which a shielding material is further arranged facing one or both sides of the conductor unit may be used.

[0104] Fig. 19 is a cross-sectional view taken along the extension direction (longitudinal direction) of a flat cable (flat electric wire) 11' according to a modified example applicable to the first embodiment, and Fig. 20 is a cross-sectional view taken along the direction perpendicular to the extension direction (lateral direction). Fig. 19 is a cross-sectional view taken along the DD section of Fig. 20, and Fig. 20 is a cross-sectional view taken along the CC section of Fig. 19.

[0105] 19 and 20, the flat cable 11' includes one conductor unit U1 consisting of two signal lines S1, S2 and a pair of ground lines G1, G2, and a pair of shielding materials SH1, SH2. The signal lines S1, S2 and the ground lines G1, G2 are the same as those of the flat cable 11 in the first embodiment.

[0106] The pair of shielding materials SH1, SH2 are arranged on both sides (upper side z and lower side z') in a direction (coordinate axis z direction) that intersects with both the arrangement direction (coordinate axis y direction) and the extension direction (coordinate axis x direction) of the signal lines S1, S2 and the ground lines G1, G2 in the conductor unit U1. The pair of shielding materials SH1, SH2 are sheet-like members made of a conductive material such as metal or conductive resin film, and are so-called solid shields with no holes on their surfaces.

[0107] The flat cable 11' is obtained by disposing a pair of shielding materials SH1, SH2 on both sides of the flat cable 11 in the first embodiment, and then laminating the peripheral surface in the extension direction (longitudinal direction, coordinate axis x direction) with an insulating resin film R. The pair of shielding materials SH1, SH2 may or may not be connected to the ground potential.

[0108] In the example flat cable 11' shown in Figures 19 and 20, shielding materials SH1, SH2 are arranged facing both sides of the conductor unit U1, but a flat cable in which a shielding material is arranged facing only one side of the conductor unit U1 may also be used. Figure 21 is a cross-sectional view taken in the extension direction (longitudinal direction) of a flat cable (flat electric wire) 11" of another modified example applicable to the first embodiment. In this modified example, a cross-sectional view taken in a direction perpendicular to the extension direction (short direction) is omitted.

[0109] As shown in FIG. 21, the flat cable 11'' includes one conductor unit U1 consisting of two signal wires S1, S2 and a pair of ground wires G1, G2, and a shielding material SH1. The signal wires S1, S2 and the ground wires G1, G2 are similar to those of the flat cable 11 in the first embodiment.

[0110] In addition, the shielding material SH1 is arranged only on one side (upper side z) in a direction (coordinate z direction) that intersects both the arrangement direction (coordinate y direction) and the extension direction (coordinate x direction) of the signal lines S1, S2 and the ground lines G1, G2 in the conductor unit U1.

[0111] The flat cable 11'' is obtained by disposing a shielding material SH1 on one side (the upper z side) of the flat cable 11 in the first embodiment, and then further laminating the peripheral surface in the extension direction (longitudinal direction, coordinate axis x direction) with an insulating resin film R. The shielding material SH1 may or may not be connected to ground potential.

[0112] In the flat cable 11' shown in Fig. 19 and Fig. 20, when the pair of shielding materials SH1, SH2 are connected to the ground potential, it is preferable to wire the shielding materials SH1, SH2 so that a ground loop is not formed. An example of a wiring method for preventing a ground loop from being formed for the shielding materials SH1, SH2 will be described with reference to Fig. 19. First, one end SH1 of the pair of shielding materials SH1, SH2 e1 ,SH2 e1 1 and 2 are connected to the ground circuit 13 of the first electronic device (one electronic device) 13. G On the other hand, the other end SH1 of the pair of shielding materials SH1 and SH2 is electrically connected to e2 ,SH2 e2 Either or both of the ground circuits 14 of the second electronic device (other electronic device) 14 G Therefore, the shielding materials SH1 and SH2 and the ground circuit 13 are not electrically connected to the G ,14 G No ground loops are formed due to this.

[0113] Similarly, another example of a wiring method in which a ground loop is not formed for the shielding materials SH1 and SH2 will be described. e2 ,SH2 e2 1 and 2 are connected to the ground circuit 14 of the second electronic device (other electronic device) 14. G On the other hand, the other end SH1 of the pair of shielding materials SH1 and SH2 is electrically connected to e1 ,SH2 e1 Either or both of the ground circuits 13 of the first electronic device (one electronic device) 13 G Therefore, the shielding materials SH1 and SH2 and the ground circuit 13 are not electrically connected to the G ,14 G No ground loops are formed due to this.

[0114] In either of the above examples or other examples, ground loops are not formed by the shielding materials SH1, SH2, eliminating concerns that ground loops may pick up external electromagnetic noise, and further reducing the effect of external electromagnetic noise on the flat cable 11' including the signal lines S1, S2.

[0115] In the flat cable 11' and flat cable 11" shown in Figures 19 to 21, the signal lines are shielded by shielding materials SH1 and SH2, thereby effectively reducing the effects of external electromagnetic noise. However, even if there is no planar shielding material like the flat cable 11 used in the embodiments shown in Figures 2 and 3, etc., the effects of external electromagnetic noise can be reduced if there is a configuration including a conductor unit in which the signal lines are sandwiched between ground wires (hereinafter referred to as a "conductor unit configuration").

[0116] That is, firstly, if the conductor unit configuration is used, the same effect as that of the shields arranged above and below can be expected from the ground lines arranged on the left and right, and external electromagnetic noise and interference can be suppressed. In addition, since the ground potential is close to the signal lines, unevenness in the ground potential can be suppressed, and external electromagnetic noise and interference can be suppressed. Furthermore, by separating them with ground lines, crosstalk from adjacent signal lines can be suppressed. Also, the conductor unit configuration is expected to have the effect of stabilizing impedance. As described above, the conductor unit configuration is expected to have the effect of improving EMC (Electromagnetic Compatibility).

[0117] In addition, those skilled in the art may implement various modifications in accordance with conventionally known knowledge without departing from the gist of the present invention. As long as the configuration of the connection structure of the flat electric wire of the present invention is still provided even after such modifications, the modification is of course included in the scope of the present invention. [Explanation of symbols]

[0118] 1, 2, 3, 4, 5, 6, 7, 8, 9: Connection structure (connection structure for flat electric wire), 11, 41, 61, 71, 81, 91: Flat cable (flat electric wire), 12: Rotating connector device, 13: First electronic device, 14: A second electronic device; A1, A2: General electrical wiring, G0, G1, G2, G3, G4: Ground wires, S1, S2, S3, S4: Signal line, U1, U1′, U1″, U2, U2′: Conductor units, SH1, SH2: Shielding material, R: Resin film

Claims

1. A connection structure for a flat electric wire that electrically connects two electronic devices, comprising: the flat electric wire includes at least one conductor unit including at least one signal line electrically connected at both ends to signal circuits of the two electronic devices, and a pair of ground lines arranged on both sides of the signal line and extending in the same direction as the signal line; A connection structure of a flat wire, in which one end of the pair of ground wires is electrically connected to the ground circuit of one of the two electronic devices, and neither or neither of the other ends of the pair of ground wires is electrically connected to the ground circuit of the other of the two electronic devices.

2. The flat electric wire connection structure according to claim 1 , wherein in the conductor unit, two or more of the signal wires are arranged side by side in the arrangement direction.

3. 2. The flat electric wire connection structure according to claim 1, wherein in said conductor unit, one or more general electric wires extend between said pair of ground wires in the same direction as said signal wires.

4. 2. The connection structure of a flat electric wire according to claim 1, wherein the flat electric wire comprises a shielding material arranged in one or both of a direction intersecting an arrangement direction and an extension direction of the signal wire and the ground wire in the conductor unit.

5. a pair of the shielding materials are arranged in both a direction intersecting a line arrangement direction and an extension direction of the signal lines and the ground lines in the conductor unit; 5. The connection structure of a flat electric wire according to claim 4, wherein one end of each of the pair of shielding materials is electrically connected to a ground circuit of one or the other of the two electronic devices, and neither or both of the other ends of the pair of shielding materials is electrically connected to a ground circuit of the remaining of the two electronic devices.

6. 2. The connection structure for a flat electric wire according to claim 1, wherein the flat electric wire is a flat cable.

7. The flat electric wire constitutes a rotary connector device together with a fixed body and a rotating body, and is entirely or partially accommodated in an accommodating space between the fixed body and the rotating body, 7. The connection structure for flat electric wires according to claim 6, wherein the two electronic devices are an ECU for a steering wheel of a vehicle and an ECU or a combination switch device on the vehicle side.

8. 7. The connection structure of claim 6, wherein the two electronic devices are an ECU for a vehicle sliding door and an ECU on a vehicle side.

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