CN109661329B - Vehicle circuit body - Google Patents

Abstract

In the present invention, a drive system ground line (74) for grounding drive system components (81, 83, 85) into which a large current flows and a signal system ground line (72) for grounding signal system components (82, 84, 86) into which a small current flows are provided independently of each other on backbone rails (61-63). It is possible to prevent a ground potential of a signal system accessory (82, 84, 86) from floating from a reference potential or a malfunction caused by voltage fluctuation due to a voltage drop in a ground path by a large current. Further, a signal system power supply line (71) and a drive system power supply line (73) which are independent of each other are provided to suppress a decrease in power supply voltage. In addition, the influence of electromagnetic noise caused by a large current is reduced.

Description

Vehicle circuit body

Technical Field

The present invention relates to a wire harness mounted on a vehicle or a vehicle circuit body having a function equivalent to the wire harness. In particular, the present invention relates to a technique of grounding.

Background

In the background art, various types of electric components called accessories are mounted at various positions on a vehicle body of a vehicle. Almost all such accessories require power supplied from a power source. Between some accessories, communication may be made or signals of switches, sensors, etc. may be transmitted.

Therefore, a wire harness or the like serving as an assembly of a large number of electric wires is laid at various positions of the vehicle body of a general vehicle. The wire harness is used to connect a power source (a battery or an alternator) on the vehicle to each accessory, and to connect the accessories to each other.

When the vehicle body belongs to a general vehicle, the vehicle body is made of conductive metal. Therefore, the vehicle body can be used as a vehicle body ground for grounding, so that it is not necessary to always incorporate a ground wire into the wire harness. On the other hand, in the case where most of the vehicle body of the vehicle is made of resin, the vehicle body ground cannot be used, so that it is necessary to prepare a ground contact member.

The wire harness described in patent document 1 has a trunk line including a power supply line, a communication line, and a ground line. Therefore, each accessory can be connected to the vehicle-side ground using the ground line on the trunk line without using the vehicle body ground.

In addition, a wire harness routing structure has been disclosed in patent document 2 in which a long ground member formed in an L-shape in cross section is provided, and a wire harness is provided at a position adjacent to the ground member. Therefore, even if the ground wire does not enter the harness, each fitting can be grounded by using the grounding member near the harness.

Reference list

Patent document

PTL1：JP-A-2015-227089

PTL2：JP-A-2016-111826

Disclosure of Invention

Technical problem

There is also a resistance in the ground line. Therefore, a relatively large voltage drop occurs particularly when a large power supply current flows through the ground. In addition, a large voltage drop also occurs at any location where current converges. Thus, the potential at the connection point between each accessory and the ground fluctuates in correspondence with the accessory.

For example, when the body ground of a vehicle is used, the sectional area of a path through which a ground current flows is sufficiently large to suppress each accessory from being adversely affected by a voltage drop generated in the path. However, when a ground wire incorporated in a wire harness or a special grounding member is used, there are cases where the sectional area of a path through which a ground current flows cannot be sufficiently ensured. Therefore, the possibility of generating a voltage drop in the ground may be increased.

In the configuration example shown in fig. 13, the signal system load 12 and the drive system load 103 are connected to a power supply line connected to the positive side terminal of the battery 101. In addition, the ground terminal of the signal system load 102 and the ground terminal of the drive system load 103 are connected to different positions of the common ground structure 104, respectively. The ground structure 104 is connected to the negative-electrode-side terminal of the battery 101. Here, a potential change (floating from a reference potential of the Ground (GND)) V11 of the signal system load at a position grounded on the ground structure 104 and a potential change V12 of the drive system load at a position grounded on the ground structure 104 are expressed by the following expressions.

V11＝(I1p+I1s)×Z11

V12＝V11+I1p×Z12

Wherein:

i1 s: supply current of signal system load

I1 p: supply current for driving a system load

Z11: resistance of path from signal system load grounding point to battery on ground structure

Z12: resistance from drive system load ground point to signal system load ground point on ground structure

That is, both currents I1s and I1p commonly flow through the ground path of signal system load 102. Assume that current I1s is small. Even in this case, when the current I1p is large, a large potential change V11 is therefore generated. In practice, the current I1s of the signaling system load in a vehicle is often very small, e.g., no higher than about 1[ A ]. However, the total current I1p driving the system load is often not less than 200[ A ]. Therefore, a large potential change V11 is generated.

When the ground potential of the signal system load fluctuates greatly, for example, a threshold fluctuation for identifying high/low of the potential of the input signal or the control signal in the signal system load. This becomes a large factor in causing a failure in the signal system load. When, for example, the drive system load 103 is running, the probability of causing a fault in the signal system load 102 may be increased at the same time.

In addition, when the ground resistances Z11 and Z12 are large, the power supply voltage applied between the terminals of the drive-system load 103 decreases by a voltage drop (V11+ V12). Therefore, the output of the drive system load 103 decreases, so that the original performance cannot be obtained. Accordingly, the voltage drop occurs not only on the ground side but also on the power supply line side in a similar or identical manner. Therefore, the power supply line side is also affected.

On the other hand, when the drive system load 103 is switched at high speed, the current for switching is large. Therefore, a large amount of electromagnetic noise is radiated from the electric wire to the periphery of the electric wire. Radiated electromagnetic noise enters the control circuitry inside the signal system load 102 via surrounding wires or directly, causing the accessory to malfunction.

The present invention has been made in view of the foregoing circumstances. An object of the present invention is to provide a vehicle circuit body capable of suppressing malfunction of any of various accessories or deterioration in performance of the accessories even when a large current flows into the accessories from a power supply on a vehicle.

Means for solving the problems

In order to achieve the foregoing object, a vehicle circuit body according to the present invention is characterized by the following configurations (1) to (6).

(1) A vehicle circuit body provided in a vehicle, the vehicle circuit body comprising:

a trunk line capable of being connected to a plurality of accessories mounted on the vehicle through branch lines or branch circuits,

the trunk line includes:

a power supply line capable of distributing and supplying electric power from a power supply mounted on the vehicle to the plurality of accessories, respectively;

a ground wire electrically connectable between a ground terminal of the power supply and the plurality of accessories; and

a communication line shared as a signal transmission line by the plurality of accessories each having a communication function, and

wherein the ground line includes:

a first ground wire connected to a fitting into which a large current flows among the plurality of fittings; and

a second ground connected to an accessory into which a current smaller than the large current flows.

(2) The vehicle circuit body according to the aforementioned configuration (1), wherein

The power supply line includes a first power supply line that supplies power to the accessory into which the large current flows, and a second power supply line that supplies power to the accessory into which a current smaller than the large current flows.

(3) The vehicle circuit body according to the foregoing configuration (1) or (2), wherein:

the first ground line and the second ground line are arranged side by side on the same routing path so as to be arranged substantially parallel to each other and electrically insulated from each other.

(4) The vehicle circuit body according to the foregoing configuration (3), wherein:

the power supply line is disposed in a space between the first ground line and the second ground line.

(5) The vehicle circuit body according to the aforementioned configuration (3), wherein

The second ground is provided at an outer position where the second ground is farther from a body surface of the vehicle than the power supply line and the first ground.

(6) The vehicle circuit body according to the foregoing configuration (1) or (2), wherein

The first ground wire is formed into a barrel; and is

The power cord and the second ground are disposed inside the barrel of the first ground.

According to the vehicle circuit body having the foregoing configuration (1), the first power supply line and the second power supply line that are selectively used according to the magnitude of current supplied to the accessory connected thereto are provided independently of each other. Therefore, the failure of the fitting can be suppressed. That is, a large current flows only into the first ground, and a current flowing into the second ground is small. Therefore, the voltage drop generated in the second ground line is reduced, so that the ground potential of the accessory using a small current is maintained substantially constant, thereby not causing a failure in the accessory. In addition, the current flowing into the second ground is small so that it is not necessary to increase the sectional area of the conductor of the path. Therefore, even when the trunk line is provided with both the first ground line and the second ground line, the trunk line can be prevented from becoming large.

According to the vehicle circuit body having the aforementioned configuration (2), the first power supply line and the second power supply line that are selectively used according to the magnitude of current supplied to the accessory connected to the first power supply line and the second power supply line are provided independently of each other. Thus, a decrease in the power supply voltage applied to the terminal of the accessory using a small current can be prevented. In addition, the current flowing into the second power supply line is small so that it is not necessary to increase the sectional area of the conductor of the path. Therefore, even when the main line is provided with both the first power supply line and the second power supply line, the main line can be prevented from being enlarged.

According to the vehicle circuit body having the aforementioned configuration (3), the first ground and the second ground are provided so as to be arranged side by side on the trunk line. Thus, even in the case where the body ground of the vehicle or a special ground member cannot be used, the trunk line can be used to ground various types of accessories.

According to the vehicle circuit body having the aforementioned configuration (4), the first ground and the second ground are connected to one side (ground side) of the power supply. Thereby, the first ground line and the second ground line can function as an electromagnetic shield. That is, electromagnetic noise radiated from the power supply line due to the current of the power supply line can be shielded so as not to be radiated to the outside of the first ground line and the outside of the second ground line. Thus, the adverse effect of noise on any of the accessories located outside the first and second ground wires can be avoided.

According to the vehicle circuit body having the aforementioned configuration (5), the second ground whose potential is substantially maintained is provided at the outermost position. Thereby, the second ground can be used as an electromagnetic shield. It is possible to suppress electromagnetic noise radiated from the power supply line or the first ground line due to the current of the power supply line or the first ground line from being radiated to the outside of the second ground line. Therefore, the adverse effect of noise on any accessories outside the second ground wire can be avoided.

According to the vehicle circuit body having the aforementioned configuration (6), the first ground line into which a large current flows is shaped into a cylindrical shape. Therefore, the voltage drop generated in the first ground line can be suppressed while suppressing an increase in the size of the main line. Furthermore, the first ground wire can function as an electromagnetic shield. Therefore, electromagnetic noise radiated from the power supply line due to the current of the power supply line can be shielded so as not to be radiated to the outside of the first ground line. Therefore, the adverse effect of noise on any accessories placed outside the first ground wire can be avoided.

Advantageous effects of the invention

According to the vehicle circuit body of the present invention, even when a large current flows into various accessories from a power supply on the vehicle, it is possible to suppress occurrence of a failure in any of the various accessories using a small current, and it is possible to suppress a reduction in performance of the accessories due to a reduction in a power supply voltage applied to the accessories.

The present invention has been described briefly above. The details of the present invention will become more apparent when the embodiments for carrying out the present invention (hereinafter referred to as "examples") described above are further read with reference to the accompanying drawings.

Drawings

Fig. 1 is a perspective view showing a configuration example of a main portion of an in-vehicle apparatus including a vehicle circuit body in a first embodiment of the invention.

Fig. 2 is a wiring diagram showing a configuration example of an in-vehicle apparatus including a vehicle circuit body in the first embodiment of the invention.

Fig. 3(a) and 3(b) are longitudinal sectional views showing the sectional structure of the trunk portion 61 having two power supply lines, respectively.

Fig. 4(a) and 4(b) are longitudinal sectional views of the cross-sectional structure of the trunk line showing changes in the positional relationship of the respective constituent elements from that of fig. 3(a) and 3(b), respectively.

Fig. 5 is a longitudinal sectional view showing a sectional structure of a trunk line according to modification 1 of the first embodiment.

Fig. 6(a) and 6(b) are longitudinal sectional views showing the sectional structure of a trunk line according to modification 2 of the first embodiment.

Fig. 7 is a longitudinal sectional view showing a sectional structure of a trunk line according to modification 3 of the first embodiment.

Fig. 8(a) and 8(b) are longitudinal sectional views showing a sectional structure of a trunk line according to modification 4 of the first embodiment.

Fig. 9 is a wiring diagram showing a configuration example of an in-vehicle apparatus including a vehicle circuit body in a second embodiment of the invention.

Fig. 10(a) and 10(B) are vertical sectional views showing the sectional structure of the trunk portion 61B having one power supply line each.

Fig. 11(a) and 11(b) are vertical sectional views of the cross-sectional structure of the trunk line showing a change in the positional relationship of the respective constituent elements from that of fig. 10(a) and 10(b), respectively.

Fig. 12(a) and 12(b) are longitudinal sectional views showing a sectional structure of a trunk line according to modification 1 of the second embodiment.

Fig. 13 is a wiring diagram showing a configuration example of a general in-vehicle device.

List of reference marks

10 power supply

10a anode side terminal

10b cathode side terminal

11 Engine room

13 vehicle room

16 dash panel

16a through hole

21. 22, 23 backbone trunk line parts

31. 32, 33 backbone control box

31a main power supply connection part

31b trunk line connection

31c branch line connecting part

41 main power supply cable

42. 43, 44 branch sub-harness

51. 52, 53 electronic control unit

61. 61B, 61C, 61D, 61E, 61F, 61G, 61H, 61J, 61K, 62B, 63B backbone trunk line portions

64. 64B, 65B, 66B backbone control box

70 outer material

71. 71B signal system power line

72. 72B signal system ground wire

73. 73B drive system power cord

74. 74B, 74C drive system ground wire

75. 77 inner conductor

76. 78 insulating coating

79 power cord

81. 83, 85 drive system fittings

82. 84, 86 signal system accessory

Detailed Description

Specific embodiments of the present invention will be described below with reference to the accompanying drawings.

(first embodiment)

Fig. 1 shows a configuration example of a main portion of an in-vehicle apparatus including a vehicle circuit body in a first embodiment of the invention.

The vehicle circuit body shown in fig. 1 is used as an accessory that supplies electric power of a main power supply such as an on-vehicle battery to respective portions of a vehicle body, i.e., transmission lines required for various electrical components or for exchanging signals between the electrical components. That is, the vehicle circuit body functions similarly to a general wire harness, but the structure is largely different from the general wire harness.

The in-vehicle device shown in fig. 1 represents an internal configuration of a vehicle compartment in the vicinity of a dash panel 16 that delimits an engine room 11 and a vehicle compartment (passenger compartment) 13 of a vehicle body. A reinforcing portion (not shown) as a reinforcing material is placed on the dash panel portion (dash panel portion) slightly rearward of the dash panel 16 so as to extend in the left/right direction of the vehicle body. The constituent elements of the vehicle circuit body are partially disposed near the reinforcing portion or near the dash panel 16.

A plurality of backbone trunk parts 21, 22, and 23 and a plurality of backbone control boxes 31, 32, and 33 are included in the vehicle circuit body shown in fig. 1. Each of the backbone trunk parts 21, 22, and 23 includes lines such as a power line, a ground line, a communication line, and the like. In addition, for example, a band-shaped metal material (such as copper or aluminum) formed in a flat shape in cross section is used for the power supply line and the ground line in the backbone trunk portion. The power supply line and the ground line are configured such that metal materials are stacked in a thickness direction in a state of being electrically insulated from each other. Thus, a large circuit is allowed to flow through the power supply line and the ground line, and the power supply line and the ground line can be bent relatively easily in the thickness direction.

The trunk line portions 21 and 22 are linearly provided in the left/right direction at a portion extending along the surface of the dash panel 16, so that the trunk line portions 21 and 22 can be substantially parallel to the reinforcing portion at a position above the reinforcing portion. Further, the trunk line portion 23 is provided at a substantially widthwise central portion of the vehicle body, and linearly extends in the up/down direction at a portion extending along the surface of the dash panel 16. In addition, the trunk stem portion 23 is bent approximately 90 ° in the thickness direction in the vicinity of the boundary between the dash panel 16 and the floor in the vehicle interior, and is provided so as to extend in the front/rear direction of the vehicle body along the floor in the vehicle interior. Incidentally, the backbone trunk parts 21 and 22 may be fixed to the reinforcing parts, or special members capable of fixing the backbone trunk parts 21 and 22 may be provided.

The backbone control box 32 is provided at a substantially widthwise center portion of the vehicle body. The backbone control box 31 is disposed near the left end in the left/right direction. The backbone control box 33 is provided near the right end in the left/right direction.

The left end of the backbone line part 21 is coupled to the right end of the backbone control box 31. The right end of the backbone trunk part 21 is coupled to the left end of the backbone control box 32. In addition, the left end of the backbone trunk line portion 22 is coupled to the right end of the backbone control box 32. The right end of the backbone trunk line portion 22 is coupled to the left end of the backbone control box 33. Further, the front end of the backbone trunk portion 23 is coupled to the lower end of the backbone control box 32.

That is, as shown in fig. 1, the backbone trunk parts 21 to 23 and the backbone control boxes 31 to 33 are configured to have a shape similar to a T shape. In addition, the internal circuits of the backbone trunk parts 21 to 23 can be electrically connected to each other via the backbone control box 32.

The backbone control box 31 provided at the left side of the vehicle body is provided with a main power supply connection portion 31a, a trunk connection portion 31b, and a branch connection portion 31 c. As shown in fig. 1, the main power supply cable 41 is connected to the main power supply connection part 31a of the backbone control box 31. The left end of the trunk line portion 21 is connected to the trunk connection portion 31 b. The plurality of branch sub-harnesses 42 are connected to the branch connection portions 31c, respectively. Incidentally, fig. 1 shows a state in which the branch sub-harness 42 has been detached from the backbone control box 31 in order to indicate that the branch sub-harness 42 can be attached/detached to/from the backbone control box 31.

In addition, although not shown in fig. 1, a dual system power supply line, a dual system ground line, and a communication line are included in the backbone trunk part 21. In addition, a plurality of connection terminals are provided in the main power supply connection portion 31a to be connected to the power supply line and the ground line of the main power supply cable 41.

In addition, the backbone control section 31 includes a circuit board for connecting the power supply system, the ground system, and the communication system of one circuit to the power supply system, the ground system, and the communication system of another circuit between the main power supply cable 41, the backbone trunk section 21, and the branch sub-harness 42, or for distribution of power among the main power supply cable 41, the backbone trunk section 21, and the branch sub-harness 42.

In the main power supply cable 41, terminals connected to ends of the power supply line and the ground line, respectively, are connected to the terminal of the main power supply connection part 31a, and are fixed to the terminal of the main power supply connection part 31a by using bolts and nuts. Thus, the aforementioned circuit can be connected.

Connectors attachable/detachable to/from the branch line connecting portions 31c are provided at the ends of the branch sub wiring harnesses 42, respectively. The circuit of the branch sub-harness 42 can be connected to the branch connecting part 31c if necessary. Each of the spur sub-harnesses 42 is configured to include all or part of a power line, a ground line, and a communication line. Incidentally, in the trunk control box 31 shown in fig. 1, the branch line connecting portion 31c is provided with six connectors, and a maximum of six branch line sub-harnesses 42 can be connected to the branch line connecting portion 31 c.

As shown in fig. 1, the backbone trunk parts 21 to 23 and the backbone control boxes 31 to 33 are combined with each other. Further, various branch sub-harnesses 42 to 44 are connected to the backbone control boxes 31 to 33. Thus, various transmission lines can be laid in a simple structure similar to the spine (diaphysis). That is, in the vehicle circuit body according to the embodiment of the invention, the backbone trunk parts 21 to 23 and the backbone control boxes 31 to 33 are configured as a backbone serving as a core part relating to distribution of power supply or transmission of communication, so that the branch sub-harness can be appropriately connected to the backbone.

For example, it is possible to mount various electrical components on the vehicle as options or additions by adding or changing only the corresponding one of the branch sub-harnesses 42 to 44 connected to one of the backbone control boxes 31 to 33. Therefore, it is not necessary to add any change to the trunk structure of the vehicle circuit body. Incidentally, a case where the branch sub-harnesses 42 to 44 are connected to the backbone control boxes 31 to 33 is assumed in the present embodiment. However, for example, any other branch sub-harness (not shown) may be connected to the location of an appropriate trunk point on any of the trunk parts 21 to 23.

For example, as shown in fig. 1, in an actual in-vehicle device, a component such as an Electronic Control Unit (ECU)51 provided in a vehicle can be connected to the backbone control box 31 or other electrical components via the branch sub-harness 42. In addition, the electronic control units 51, 52, and 53 or other electrical components can be connected to the backbone control box 32 via the branch sub-harness 43. Further, various electrical components can be connected to the backbone control box 33 via the branch sub-harness 44. Each of the electronic control units 51, 52, and 53 is capable of controlling various electrical components on the vehicle via the communication lines of the branch sub-harnesses 42, 43, and 44, and the backbone control boxes 31 to 33 and the like.

Next, specific examples of the circuit configuration will be described.

Fig. 2 shows a configuration example of an in-vehicle apparatus including a vehicle circuit body in a first embodiment of the invention. The in-vehicle apparatus shown in fig. 2 is provided with: backbone trunk portions 61, 62, and 63; backbone control boxes 64, 65, and 66; a plurality of drive system accessories 81(1) to 81(N), 83(1) to 83(N), and 85(1) to 85 (N); and a plurality of signal system components 82(1) to 82(N), 84(1) to 84(N) and 86(1) to 86 (N).

As shown in fig. 2, each of the backbone trunk parts 61, 62, and 63 is provided with four independent lines, i.e., a signal system power supply line 71, a signal system ground line 72, a drive system power supply line 73, and a drive system ground line 74.

The signal system power supply line 71 and the signal system ground line 72 are power supply lines and ground lines prepared for supplying power supply power to accessories (referred to as "signal system accessories" in the present embodiment) that consume relatively small power supply currents, for example, rated currents not exceeding 10[ a ], respectively. For example, a meter unit, an audio device, various Electronic Control Units (ECUs), a small lighting device, and the like mounted on a vehicle correspond to "signal system accessories".

On the other hand, the drive system power supply line 73 and the drive system ground line 74 are power supply lines and ground lines prepared for supplying power supply power to accessories (referred to as "drive system accessories" in the present embodiment) that consume relatively large power supply currents, for example, rated currents exceeding 10[ a ], respectively. For example, a motor, various heaters, headlamps, and the like for generating driving forces of various actuators on a vehicle correspond to "drive system accessories".

Various accessories classified into the category "drive system accessories" are connected to a drive system power supply line 73 and a drive system ground line 74. Therefore, the current of the drive system for the entire vehicle is large, reaching about 200 to 300[ a ] at the peak. On the other hand, only the accessories, which respectively consume less current than the drive system accessories, classified into the category "signal system accessories" are connected to the signal system power supply line 71 and the signal system ground line 72. Therefore, the peak value of the current flowing into the signal system power supply line 71 and the signal system ground line 72 is very small compared with the peak value of the current flowing into the drive system power supply line 73 and the drive system ground line 74.

In the configuration shown in fig. 2, one end sides of the signal system power supply line 71 and the drive system power supply line 73 included in the backbone trunk line portion 61 are connected to the anode-side terminal 10a of the power supply 10, respectively, and the other end side is connected to the backbone control box 64. The power supply 10 corresponds to a main battery or an alternator mounted on a vehicle. In addition, one end sides of the signal system ground 72 and the drive system ground 74 included in the backbone trunk portion 61 are connected to the cathode-side terminal 10b of the power supply 10, respectively, and the other end side is connected to the backbone control box 64.

In addition, a signal system power supply line 71, a signal system ground line 72, a drive system power supply line 73, and a drive system ground line 74 included in the backbone trunk portion 61 are connected to the corresponding lines included in the backbone trunk portion 62, respectively. In addition, a signal system power supply line 71, a signal system ground line 72, a drive system power supply line 73, and a drive system ground line 74 included in the backbone trunk portion 61 are connected to the corresponding lines included in the backbone trunk portion 63 via the internal circuits of the backbone control box 64, respectively.

As shown in fig. 2, a signal system power distribution section, a signal system GND (ground, i.e., earth) distribution section, a drive system power distribution section, and a drive system GND distribution section are provided in the respective backbone control boxes 64, 65, and 66. The signal system power distribution section is connected to the signal system power supply line 71. The signal system GND distribution section is connected to the signal system ground 72. The drive system power distribution section is connected to a drive system power supply line 73. The drive system GND distribution section is connected to the drive system ground 74.

As shown in fig. 2, a plurality of drive system components 81(1) to 81(N) and a plurality of signal system components 82(1) to 82(N) are connected below the backbone control box 64. The fittings are connected to backbone control box 64 via branch sub-wiring harnesses, respectively.

In a similar or identical manner, a plurality of drive system components 83(1) to 83(N) and a plurality of signal system components 84(1) to 84(N) are connected below the backbone control box 65. In addition, a plurality of drive system components 85(1) to 85(N) and a plurality of signal system components 86(1) to 86(N) are connected below the backbone control box 66.

For example, inside the backbone control box 64, the drive system power distribution section distributes the power supply power of the drive system power supply line 73 to a plurality of paths, respectively. The electric power distributed by the drive system power distribution sections, respectively, is supplied to the power terminals of the drive system accessories 81(1) to 81(N) via the branch sub-harnesses, respectively. Also for the ground side, the driving system GND dividing section divides the driving system ground 74 into a plurality of current paths. The separate current paths are connected to the ground terminals of the drive system accessories 81(1) to 81(N) via branch sub-wiring harnesses, respectively.

Further, inside the backbone control box 64, the signal system power distribution section distributes the power supply power of the signal system power supply line 71 to a plurality of paths, respectively. The electric power distributed by the signal system power distribution unit is supplied to the power terminals of the signal system accessories 82(1) to 82(N) via the branch sub-line bundles, respectively. Also for the ground side, the signal system GND dividing section divides the signal system ground 72 into a plurality of current paths. The separate current paths are connected to the ground terminals of the signal system accessories 82(1) to 82(N) via branch sub-wiring harnesses, respectively.

Also inside the backbone control box 65, the drive system power distribution section distributes the power supply power of the drive system power supply line 73 to a plurality of paths, respectively. The electric power distributed by the drive system power distribution sections, respectively, is supplied to the power terminals of the drive system accessories 83(1) to 83(N) via the branch sub-harnesses, respectively. In addition, the driving system GND dividing portion divides the driving system ground 74 into a plurality of current paths. The separate current paths are connected to the ground terminals of the drive system accessories 83(1) to 83(N) via branch sub-wiring harnesses, respectively.

Further, inside the backbone control box 65, the signal system power distribution section distributes the power supply power of the signal system power supply line 71 to a plurality of paths, respectively. The electric power distributed by the signal system power distribution unit is supplied to the power terminals of the signal system accessories 84(1) to 84(N) via the branch sub-line bundles. Also for the ground side, the signal system GND dividing section divides the signal system ground 72 into a plurality of current paths. The separate current paths are connected to the ground terminals of the signal system accessories 84(1) to 84(N) via branch sub-wiring harnesses, respectively.

Also inside the backbone control box 66, the drive system power distribution section distributes the power supply power of the drive system power supply line 73 to a plurality of paths, respectively. The electric power distributed by the drive system power distribution sections, respectively, is supplied to the power terminals of the drive system accessories 85(1) to 85(N) via the branch sub-harnesses, respectively. In addition, the driving system GND dividing portion divides the driving system ground 74 into a plurality of current paths. The separate current paths are connected to the ground terminals of the drive system accessories 85(1) to 85(N) via branch sub-wiring harnesses, respectively.

Further, inside the backbone control box 66, the signal system power distribution section distributes the power supply power of the signal system power supply line 71 to a plurality of paths, respectively. The electric power distributed by the signal system power distribution unit is supplied to the power terminals of the signal system accessories 86(1) to 86(N) via the branch sub-line bundles. Also for the ground side, the signal system GND dividing section divides the signal system ground 72 into a plurality of current paths. The separate current paths are connected to the ground terminals of the signal system accessories 86(1) to 86(N) via branch sub-wiring harnesses, respectively.

Therefore, similarly to the drive system accessories 81(1) to 81(N), 83(1) to 83(N), and 85(1) to 85(N) in the configuration shown in fig. 2, the power supply current is supplied through the drive system power supply line 73, and the ground side current flows through the drive system ground line 74. On the other hand, similarly to any of the signal system components 82(1) to 82(N), 84(1) to 84(N), and 86(1) to 86(N), the power supply current is supplied through the signal system power supply line 71, and the ground side current flows through the signal system ground line 72.

That is, between the signal system and the drive system, the power supply current supply path to each accessory is completely independent of the ground current flow path to the accessory. Therefore, also in any current path on the backbone trunk parts 61, 62, and 63, the voltage drop due to the power supply current and the ground current flowing into the drive system components 81(1) to 81(N), 83(1) to 83(N), or 85(1) to 85(N) does not affect the voltage of the current path of the signal system components 82(1) to 82(N), 84(1) to 84(N), or 86(1) to 86 (N). In addition, the magnitude of the current flowing into the signal system components 82(1) to 82(N), 84(1) to 84(N), or 86(1) to 86(N) is smaller than the current flowing into the drive system components 81(1) to 81(N), 83(1) to 83(N), or 85(1) to 85 (N).

Therefore, even when the cross-sectional area of the conductor of each line is comparatively small, the voltage drop in the signal system power supply line 71 and the voltage in the signal system ground line 72 are reduced to allowable levels, respectively. Therefore, it is possible to prevent the respective ground potentials of the signal system components 82(1) to 82(N), 84(1) to 84(N), and 86(1) to 86(N) from increasing or fluctuating with respect to the reference potential of the ground, that is, the potential of the cathode-side terminal 10b of the power supply 10. Thus, a malfunction can be prevented from occurring in each of the signal system components 82.

In addition, the voltage drop in the power supply line and the ground line is reduced, so that the power supply voltage applied between the terminals of the signal system accessory 82 can be prevented from being lowered. Thus, the signaling system component 82 can exert a predetermined performance that satisfies its rated value. When, for example, a lighting unit of a vehicle such as a stop lamp or a tail lamp is connected as one of the signal fittings 82, it is possible to prevent the light amount of the stop lamp or the tail lamp from being reduced.

Incidentally, although not shown in fig. 2, communication lines can also be included in the respective backbone trunk parts 61 to 63. Thus, the trunk line can be used for communication between a plurality of accessories.

Next, a specific configuration example of the backbone trunk part will be described.

Fig. 3(a) and 3(b) are views showing the cross-sectional structure of the backbone trunk portion 61 having two power supply lines, respectively. Incidentally, the cross-sectional shapes of the respective power supply lines and the respective communication lines constituting the backbone trunk line part 61 differ between fig. 3(a) and 3 (b).

< configuration example 1>

In the configuration shown in fig. 3(a), the signal system power supply line 71, the signal system ground line 72, the drive system power supply line 73, and the drive system ground line 74 constituting the backbone trunk line portion 61 are each constituted by a coated electric wire having a circular cross section. The covered electric wire is composed of an inner conductor 75 formed in a circular shape in cross section and an insulating cover 76 covering the entire outer periphery of the inner conductor 75. The insulating coating 76 is made of resin or the like. Therefore, the signal system power supply line 71, the signal system ground line 72, the drive system power supply line 73, and the drive system ground line 74 are electrically isolated from each other.

In addition, the signal system power supply line 71, the signal system ground line 72, the drive system power supply line 73, and the drive system ground line 74 are arranged in a row and are disposed parallel to each other. The drive system power supply line 73 is provided so as to be sandwiched between the signal system ground line 72 and the drive system ground line 74.

With the layout thus set, electromagnetic noise radiation to the outside can be suppressed. That is, since a large current flows into the drive system power supply line 73, large electromagnetic noise is radiated from the drive system power supply line 73 in accordance with switching of the current or the like. However, since the potential of the signal system ground line 72 and the potential of the drive system ground line 74 are substantially equal to the reference potential of the ground, the signal system ground line 72 and the drive system ground line 74 can be electromagnetically shielded. Therefore, electromagnetic noise can be suppressed from radiating to the outside of the signal system ground 72 and the drive system ground 74.

Incidentally, in order to fix the signal system power supply line 71, the signal system ground line 72, the drive system power supply line 73, and the drive system ground line 74 in the positional relationship shown in fig. 3(a), for example, the lines 71 to 74 may be integrated by bonding, or may be externally covered by an unillustrated exterior material to be integrated. In addition, the currents flowing through the respective signal system power supply lines 71 and the signal system ground lines 72 are relatively small. Therefore, the sectional area of the inner conductor 75 in each of the signal system power supply line 71 and the signal system ground line 72 can be made smaller than the sectional area of the inner conductor 75 in each of the drive system power supply line 73 and the drive system ground line 74.

< configuration example 2>

In the configuration shown in fig. 3(B), the signal system power supply line 71B, the signal system ground line 72B, the drive system power supply line 73B, and the drive system ground line 74B constituting the backbone trunk line portion 61 are each constituted by a plate-like coated electric wire having a flat cross section. The covered electric wire is composed of: a plate-shaped inner conductor 77 having a flat cross section; and an insulating coating 78 that entirely covers the outer periphery of the inner conductor 77. The insulating coating 78 is made of resin or the like. Therefore, the signal system power supply line 71B, the signal system ground line 72B, the drive system power supply line 73B, and the drive system ground line 74B are electrically isolated from each other.

In addition, the signal system power supply line 71B, the signal system ground line 72B, the driving system power supply line 73B, and the driving system ground line 74B are stacked on one another in their thickness direction so as to be arranged in one row and disposed parallel to one another. The drive system power supply line 73B is provided so as to be sandwiched between the signal system ground line 72 and the drive system ground line 74.

With the layout thus set, electromagnetic noise radiation to the outside can be suppressed. That is, since a large current flows into the drive system power supply line 73B, large electromagnetic noise is radiated from the drive system power supply line 73B in accordance with switching of the current or the like. However, since the potential of the signal system ground line 72B and the potential of the drive system ground line 74B are substantially equal to the reference potential of the ground, respectively, the signal system ground line 72B and the drive system ground line 74B can be electromagnetically shielded. Therefore, electromagnetic noise can be suppressed from radiating to the outside of the signal system ground 72B and the drive system ground 74B.

Incidentally, in order to fix the signal system power supply line 71B, the signal system ground line 72B, the drive system power supply line 73B, and the drive system ground line 74B in the positional relationship shown in fig. 3(B), for example, the lines 71B to 74B may be integrated by bonding, or may be externally covered by an unshown exterior material to be integrated. In addition, the current flowing through each of the signal system power supply line 71B and the signal system ground line 72B is relatively small. Therefore, the sectional area of the inner conductor 75 in each of the signal system power supply line 71B and the signal system ground line 72B can be made smaller than the sectional area of the inner conductor 75 in each of the drive system power supply line 73B and the drive system ground line 74B.

< configuration example 3>

Fig. 4(a) and 4(b) are views showing the cross-sectional structure of the backbone trunk portion 61, and the positional relationship of the respective constituent elements in each of the backbone trunk portions 61 is changed from the positional relationship shown in fig. 3(a) and 3 (b). Incidentally, for the backbone trunk line portions 62 and 63, the same configuration as that of the backbone trunk line portions 61 is used.

A signal system power supply line 71, a signal system ground line 72, a drive system power supply line 73, and a drive system ground line 74 of the same configuration as that shown in fig. 3(a) are also provided in the configuration shown in fig. 4 (a). However, the layout of these lines 71 to 74 in the configuration shown in fig. 4(a) is different from that in the configuration shown in fig. 3 (a).

Specifically, the signal system power supply line 71, the signal system ground line 72, the drive system power supply line 73, and the drive system ground line 74 are arranged in a row and are disposed parallel to each other. The signal system ground 72 and the drive system ground 74 are disposed outside. The signal system power supply line 71 and the drive system power supply line 73 are provided so as to be sandwiched between the signal system ground line 72 and the drive system ground line 74.

With the layout thus set, electromagnetic noise radiation to the outside can be suppressed. That is, since a large current flows into the drive system power supply line 73, large electromagnetic noise is radiated from the drive system power supply line 73 in accordance with switching of the current or the like. In addition, although the electromagnetic noise is relatively small, it is also radiated from the signal system power supply line 71. However, since the potential of the signal system ground 72 and the potential of the drive system ground 74 are substantially equal to the reference potential of the ground, respectively, the signal system ground 72 and the drive system ground 74 can be electromagnetically shielded. Therefore, electromagnetic noise can be suppressed from radiating to the outside of the signal system ground 72 and the drive system ground 74.

Incidentally, in order to fix the signal system power supply line 71, the signal system ground line 72, the drive system power supply line 73, and the drive system ground line 74 in the positional relationship shown in fig. 4(a), for example, the lines 71 to 74 may be integrated by bonding, or may be externally covered by an unillustrated exterior material to be integrated.

< configuration example 4>

The signal system power supply line 71B, the signal system ground line 72B, the drive system power supply line 73B, and the drive system ground line 74B of the same configuration as that shown in fig. 3(B) are also used in the configuration shown in fig. 4 (B). However, the layout of these lines 71B to 74B in the configuration shown in fig. 4(B) is different from that in the configuration shown in fig. 3 (B).

Specifically, the signal system power supply line 71B, the signal system ground line 72B, the driving system power supply line 73B, and the driving system ground line 74B are stacked on one another in their thickness direction so as to be arranged in a row and are disposed parallel to one another. The signal system power supply line 71B and the drive system power supply line 73B are disposed so as to be sandwiched between the signal system ground line 72B and the drive system ground line 74B.

With the layout thus set, electromagnetic noise radiation to the outside can be suppressed. That is, since a large current flows into the drive system power supply line 73B, large electromagnetic noise is radiated from the drive system power supply line 73B in accordance with switching of the current or the like. In addition, although the electromagnetic noise is relatively small, it is also radiated from the signal system power supply line 71B. However, since the potential of the signal system ground line 72B and the potential of the drive system ground line 74B are substantially equal to the reference potential of the ground, respectively, the signal system ground line 72B and the drive system ground line 74B can be electromagnetically shielded. Therefore, electromagnetic noise can be suppressed from radiating to the outside of the signal system ground 72B and the drive system ground 74B.

Incidentally, in order to fix the signal system power supply line 71B, the signal system ground line 72B, the drive system power supply line 73B, and the drive system ground line 74B in the positional relationship shown in fig. 4(B), for example, the lines 71B to 74B may be integrated by bonding, or may be externally covered by an unshown exterior material to be integrated.

< modification of the cross-sectional structure of trunk line >

< modification 1>

Fig. 5 shows a cross-sectional structure of the backbone trunk portion 61C. The backbone trunk portion 61C shown in fig. 5 can achieve a function equivalent to that of the backbone trunk portion 61 having the structure shown in fig. 3 (b).

In the trunk portion 61C shown in fig. 5, the signal system power supply line 71B, the signal system ground line 72B, and the drive system power supply line 73B, which are respectively formed in a plate shape, are stacked, and the exterior is covered with a drive system ground line 74C constituting an exterior material (housing). For example, the exterior material is made of a conductive metal such as aluminum. Therefore, the exterior material can be used as a conductor for grounding. In addition, the exterior material can easily secure a sufficiently large sectional area. Therefore, the exterior material is suitable for use as a ground conductor capable of flowing a large current.

As shown in fig. 5, the signal system power source 71B and the drive system power source line 73B are externally covered with an external material constituting a drive system ground 74C. Thus, the exterior material can effectively achieve the electromagnetic shielding function. That is, the potential of the drive system ground 74C is substantially equal to the reference potential of the ground. Therefore, it is possible to prevent electromagnetic noise generated by a current flowing through the drive system power supply line 73 and the like from being radiated to the outside of the backbone trunk line portion 61C.

< modification 2>

The cross-sectional structures of the backbone trunk portions 61D and 61E are shown in fig. 6(a) and 6(b), respectively.

As shown in fig. 6(a), the backbone trunk portion 61D is similar to the backbone trunk portion 61C in that a tubular drive system ground 74C is provided. However, the backbone trunk portion 61D is different from the backbone trunk portion 61C in that: the outer periphery of the drive system ground 74C is entirely covered with the exterior material (housing) 70. The exterior material 70 is made of an insulator of resin or the like, and is formed in a cylindrical shape to cover the ground wire 74C. Thus, the backbone trunk portion 61D can achieve a similar or identical function to the backbone trunk portion 61C. Further, since the outer material 70 of the outer periphery is used as a covering, the durability of the trunk line portion 61D can be improved.

In addition, the backbone trunk portion 61E shown in fig. 6(b) has the same or similar exterior material 70 as in the backbone trunk portion 61D, and only the cross-sectional shapes of the drive system power supply line, the signal system power supply line, and the signal system ground line are different from the backbone trunk portion 61D. Therefore, the durability of the backbone trunk portion 61E can be improved similarly or identically to the backbone trunk portion 61D.

< modification 3>

Fig. 7 shows a sectional structure of the backbone trunk portion 61F. The trunk line portion 61F shown in fig. 7 can also achieve a function equivalent to the trunk line portion 61 having the structure shown in fig. 3 (b).

The signal system power supply line 71B, the drive system power supply 73B, and the drive system ground 74B, which are each formed in a plate shape, are laminated, and the outside is covered with an exterior material 70. For example, the exterior material 70 can be made of resin or the like in a similar or the same manner as in modification 2. However, the exterior material 70 may be an electrical conductor.

In addition, the outer periphery of the exterior material 70 is covered with a thin electrical conductor (metal such as aluminum) constituting the signal system ground 72C. Incidentally, the signal system ground 72 may be provided along the inner wall of the exterior material 70. Since a large current does not flow into the signal system ground 72C, it is not necessary to increase the sectional area of the conductor.

As shown in fig. 7, the signal system ground line 72C is provided so as to surround the exterior material 70 to externally cover the signal system power supply line 71B and the drive system power supply line 73. Thus, the signal system ground line 72C can effectively achieve the electromagnetic shielding function. That is, the potential of the signal system ground line 72C is substantially equal to the reference potential of the ground. Therefore, it is possible to prevent electromagnetic noise generated by a current flowing through the drive system power supply line 73 and the like from being radiated to the outside of the backbone trunk portion 61F.

< modification 4>

Cross-sectional structures of the trunk line portions 61G and 61H are shown in fig. 8(a) and 8(b), respectively.

As shown in fig. 8(a), the backbone trunk portion 61G is similar to the backbone trunk portion 61D shown in modification 2 in that: a cylindrical drive system ground 74C is provided, and the outer periphery of the drive system ground 74C is completely covered with the exterior material (housing) 70. However, the backbone trunk portion 61G is different from the backbone trunk portion 61D in that: four lines, i.e., a signal system power supply line 71, a signal system ground line 72, a drive system power supply line 73, and a drive system ground line 74 are provided inside the tubular drive system ground line 74C.

That is, the backbone trunk portion 61G has two drive system ground lines, i.e., a drive system ground line 74 formed in a circular sectional shape and a drive system ground line 74C formed in a cylindrical shape. Therefore, the ground conductor can be ensured to have a large total cross-sectional area and to be able to pass a large current. Further, the drive system ground 74C externally covers the signal system power supply line 71 and the drive system power supply line 73, thereby effectively achieving an electromagnetic shielding function.

In addition, the backbone trunk portion 61H shown in fig. 8(b) has a tubular drive system ground 74C and a drive system power supply line, a signal system ground, and a drive system ground surrounded by the drive system ground 74C in a similar or identical manner to the backbone trunk portion 61G. However, only the cross-sectional shapes of the power supply line and the ground line in the trunk line portion 61H are different from those in the trunk line portion 61G. Therefore, in the backbone trunk portion 61H as well, the drive system ground 74C is applied as a conductor for grounding through which a large current can flow. Further, the drive system ground 74C externally covers the signal system power supply line 71 and the drive system power supply line 73, thereby effectively achieving an electromagnetic shielding function.

(second embodiment)

Fig. 9 is a wiring diagram showing an in-vehicle apparatus including a vehicle circuit body in a second embodiment of the invention. Incidentally, the same constituent elements as those of the first embodiment will be denoted by the same reference numerals, respectively, and the description thereof will be omitted.

The in-vehicle apparatus shown in fig. 9 has the following configuration: in use, the power supply lines 79 of the backbone trunk portions 61B, 62B, and 63B are shared by the drive system components 81, 83, and 85 and the signal system components 82, 84, and 86. That is, the signal system power supply line 71 and the drive system power supply line 73 shown in fig. 2 are replaced with a common power supply line 79. In addition, the power distribution portion in each of the backbone control boxes 64B, 65B, and 66B is shared by the signal system and the drive system.

In the configuration shown in figure 9, in use, the power supply line 79 is shared by the signalling system and the drive system. Therefore, there is a possibility that: the power supply voltage applied to the signal system components 82, 84, and 86 may be lowered due to a voltage drop caused by a large current flowing into the drive system components 81, 83, and 85. However, in a manner similar or identical to the configuration shown in fig. 2, the ground-side lines are independent of each other between the signaling system and the drive system. Therefore, the ground potentials of the signal- system components 82, 84, and 86 are not affected by a large current, so that it is possible to prevent a malfunction from being generated in the signal-system components.

The backbone trunk parts 61B, 62B, and 63B shown in fig. 9 are each constituted by three lines, i.e., a power supply line 79, a signal system ground line 72, and a drive system ground line 74. Therefore, for example, the backbone trunk portions 61B, 62B, and 63B can have a structure shown in any of fig. 10(a), 10(B), 11(a), and 11 (B).

In the structure shown in fig. 10(a), the power supply line 79, the signal system ground line 72, and the drive system ground line 74 constituting the backbone trunk line portion 61B are each formed of a coated power supply having a circular cross section. The covered electric wire is composed of an inner conductor 75 whose cross section is formed in a circular shape and an insulating cover 76 that entirely covers the outer periphery of the inner conductor 75. The insulating coating 76 is made of resin or the like. Thus, the power supply line 79, the signal system ground line 72, and the drive system ground line 74 are electrically isolated from each other.

In addition, the electric wire source 79, the signal system ground 72, and the drive system ground 74 are arranged in a row and are disposed parallel to each other. The power supply line 79 is provided so as to be sandwiched between the signal system ground line 72 and the drive system ground line 74.

With the layout thus set, electromagnetic noise radiation to the outside can be suppressed. That is, since a large current flows into the power supply line 79, a large electromagnetic noise is radiated from the power supply line 79 in accordance with switching of the current or the like. However, since the potential of the signal system ground 72 and the potential of the drive system ground 74 are substantially equal to the reference potential of the ground, respectively, the signal system ground 72 and the drive system ground 74 can be electromagnetically shielded. Therefore, electromagnetic noise can be suppressed from radiating to the outside of the signal system ground 72 and the drive system ground 74.

Incidentally, in order to fix the power supply line 79, the signal system ground line 72, and the drive system ground line 74 in the positional relationship shown in fig. 10(a), for example, the lines 79, 72, and 74 may be integrated by bonding, or the outside may be covered with an unshown exterior material to be integrated. In addition, the current flowing through the signal system ground 72 is relatively small. Therefore, in practice, the sectional area of the inner conductor 75 in the signal system ground 72 can be made smaller than the sectional area of the inner conductor of the drive system ground 74.

In the structure shown in fig. 10(B), the power supply line 79B, the signal system ground line 72B, and the drive system ground line 74B constituting the backbone trunk line portion 61B are each formed of a plate-like coated electric wire having a flat cross section. The covered electric wire is composed of: a plate-shaped inner conductor 77 having a flat cross section; and an insulating coating 78 that entirely covers the outer periphery of the inner conductor 77. The insulating coating 78 is made of resin or the like. Thus, the power supply line 79B, the signal system ground line 72B, and the drive system ground line 74B are electrically isolated from each other.

In addition, the power supply line 79B, the signal system ground line 72B, and the drive system ground line 74B are stacked on one another in their thickness direction so as to be arranged in a row and disposed parallel to one another. The power supply line 79B is provided so as to be sandwiched between the signal system ground line 72B and the drive system ground line 74B.

When the layout is thus set, electromagnetic noise radiation to the outside can be suppressed. That is, since a large current flows into power supply line 79B, large electromagnetic noise is radiated from power supply line 79B in accordance with switching of the current or the like. However, since the potential of the signal system ground line 72B and the potential of the drive system ground line 74B are substantially equal to the reference potential of the ground, respectively, the signal system ground line 72B and the drive system ground line 74B can be electromagnetically shielded. Therefore, the electromagnetic noise can be suppressed from being radiated to the outside of the signal system ground 72B and the drive system ground 74B.

Incidentally, in order to fix the power supply line 79B, the signal system ground line 72B, and the driving system ground line 74B in the positional relationship shown in fig. 10(B), for example, the lines 79B, 72B, and 74B may be integrated by bonding, or the outside may be covered with an unillustrated exterior material to be integrated. In addition, the current flowing through the signal system ground 72B is relatively small. Therefore, in practice, the sectional area of the inner conductor 75 in the signal system ground 72B can be made smaller than the sectional area of the inner conductor of the drive system ground 74B.

In the configuration shown in fig. 11(a), the signal system ground line 72, the drive system ground line 74, and the power supply line 79 are provided arranged in one row. In addition, a signal system ground 72 is provided at the left end of the row, a drive system ground 74 is provided at the center of the row, and a power supply line 79 is provided at the right end of the row.

For example, assume that the power supply line 79 in the configuration of fig. 11(a) is provided at a position near the surface of the vehicle body or near the surface of the accessory. Therefore, the signal system ground 72 and the drive system ground 74 are disposed at external positions away from the surface of the vehicle body or the like. Therefore, electromagnetic noise can be suppressed from being radiated from the power supply line 79 to the outside by the electromagnetic shielding function of the signal system ground 72 and the drive system ground 74.

In the configuration shown in fig. 11(B), the signal system ground line 72B, the drive system ground line 74B, and the power supply line 79B are arranged in a row in their thickness direction, and are provided in a stacked state. In addition, the signal system ground line 72B is disposed at the uppermost portion of the row, the driving system ground line 74B is disposed at the center of the row, and the power supply line 79B is disposed at the lowermost portion of the row.

For example, assume that power supply line 79B at the lowermost portion in the configuration of fig. 11(B) is provided at a position near the surface of the vehicle body or near the surface of the accessory. Therefore, the signal system ground 72B and the drive system ground 74B are provided at outer positions away from the surface of the vehicle body or the like. Therefore, electromagnetic noise can be suppressed from being radiated to the outside from the power supply line 79B by the electromagnetic shielding function of the signal system ground line 72B and the drive system ground line 74B.

< modification 1 of the second embodiment >

Cross-sectional structures of the trunk line portions 61J and 61K are shown in fig. 12(a) and 12(b), respectively.

As shown in fig. 12(a), the backbone trunk portion 61J is similar in configuration to the backbone trunk portion 61B shown in fig. 10 in that: the signal system power supply line 71 and the drive system power supply line 72 shown in fig. 2 are replaced by a common power supply line 79. However, the backbone trunk portion 61J is different from the backbone trunk portion 61B in that: a drive system ground 74C having a cylindrical shape in cross section instead of a circular shape is provided. The backbone trunk portion 61J is also different from the backbone trunk portion 61B in that: the outer periphery of the drive system ground 74C is entirely covered with the exterior material (housing) 70. The exterior material 70 is composed of an insulator made of resin or the like, and is formed in a cylindrical shape so as to cover the ground wire 74C.

Thus, the trunk line portion 61J can achieve a similar or identical function to the trunk line portion 61C. Further, since the outer material 70 of the outer periphery is used as a covering, the durability of the trunk line portion 61J can be improved. In addition, only two lines, i.e., the signal system ground line 72 and the power supply line 79, are housed in the barrel formed by the ground line 74C. Therefore, the cross-sectional area of the trunk portion 61J can be further reduced.

In addition, the trunk portion 61K shown in fig. 12(b) has the same or similar exterior material 70 as in the trunk portion 61J, and only the cross-sectional shapes of the power supply line and the signal system ground are different from the trunk portion 61J. Therefore, the trunk line portion 61K can also obtain similar or identical effects to the trunk line portion 61J.

< other modifications >

In the in-vehicle device shown in fig. 2, both the signal system ground 72 and the drive system ground 74 are included in each of the backbone trunk parts 61 to 63. However, in the case of an in-vehicle device mounted on a vehicle whose body is made of metal, the body ground can also be used. When the body ground can be used, one of the signal system ground 72 and the drive system ground 74 in the trunk wiring portions 61 to 63 can be replaced by the body ground.

< advantageous effects of vehicle Circuit body >

In any of the foregoing configurations, the signal system ground 72 and the drive system ground 74 are provided independently of each other, and the ground of each drive system component 81 and the ground of each signal system component 82 are separated from each other. Thereby, the ground potential of the signal system accessory 82 can be prevented from floating or fluctuating from the reference potential, so that the signal system accessory 82 can be prevented from malfunctioning. In addition, a decrease in the power supply voltage applied to the signal system accessory 82 can be suppressed, so that the performance of the signal system accessory 82 can be prevented from decreasing below its rated value. In addition, the power supply line is divided into a power supply line for the driving system accessory 81 and a power supply line for the signal system accessory 82, as shown in fig. 2. Thus, the power supply voltage applied to the signal system accessory 82 can be further suppressed from decreasing.

Here, the foregoing characteristics of the embodiment of the vehicle circuit body according to the invention will be briefly summarized and listed in the following configurations [1] to [6], respectively.

[1] A vehicle circuit body disposed on a vehicle, the vehicle circuit body comprising:

trunk lines (trunk line portions 61 to 63) that can be connected to a plurality of accessories mounted on the vehicle through branch lines or branch circuits; wherein:

the trunk line includes:

power supply lines (signal system power supply line 71, drive system power supply line 73, power supply line 79) capable of distributing and supplying electric power from a power supply mounted on the vehicle to the plurality of accessories, respectively;

a ground wire electrically connectable between a ground terminal of the power supply and the plurality of accessories; and

a communication line shared by the plurality of accessories each having a communication function as a signal transmission line; and is provided with

The ground wire includes: a first ground (drive system ground 74) connected to an accessory ( drive system accessory 81, 83, 85) to which a large current flows among the plurality of accessories, and a second ground (signal system ground 72) connected to an accessory to which a current smaller than the large current flows among the plurality of accessories.

[2] The vehicle circuit body according to the foregoing configuration [1], wherein:

the power cord includes: a first power supply line (drive system power supply line 73) that supplies power to the accessory ( drive system accessory 81, 83, 85) into which the large current flows, and a second power supply line (signal system power supply line 71) that supplies power to the accessory ( signal system accessory 82, 84, 86) into which a current smaller than the large current flows.

[3] The vehicle circuit body according to the foregoing configuration [1] or [2], wherein:

the first ground line and the second ground line are arranged side by side on the same routing path so as to be arranged substantially parallel to each other and electrically insulated from each other (see fig. 3).

[4] The vehicle circuit body according to the foregoing configuration [3], wherein:

the power supply line is disposed in a space between the first ground line and the second ground line (see fig. 3).

[5] The vehicle circuit body according to the foregoing configuration [3], wherein:

the second ground is provided at an outer position where the second ground is farther from a body surface of the vehicle than the power supply line and the first ground.

[6] The vehicle circuit body according to the foregoing configuration [1] or [2], wherein:

the first ground wire is formed into a barrel; and is

The power cord and the second ground are disposed inside the barrel of the first ground.

The invention has been described in detail with reference to specific embodiments thereof. However, it will be apparent to those skilled in the art that various changes or modifications can be made to the present invention without departing from the principle and scope of the invention.

The present application is based on the japanese patent application (patent application No. 2016-.

Industrial applicability

According to the present invention, the following effects are obtained: it is possible to provide a vehicle circuit body capable of suppressing a failure in various accessories or a reduction in the performance of the accessories even when a large current flows into the accessories from a power supply on the vehicle. The present invention, which achieves the above-described effects, is applied to a wire harness mounted on a vehicle or a vehicle circuit body having a function equivalent to the wire harness.

Claims (3)

1. A vehicle circuit body provided in a vehicle, the vehicle circuit body comprising:

a trunk line capable of being connected to a plurality of accessories mounted on the vehicle through branch lines or branch circuits,

wherein the trunk line comprises:

a power supply line capable of distributing and supplying electric power from a power supply mounted on the vehicle to the plurality of accessories, respectively;

a ground wire electrically connectable between a ground terminal of the power supply and the plurality of accessories; and

a communication line shared as a signal transmission line by the plurality of accessories each having a communication function,

wherein the ground line includes:

a first ground line connected to a component into which a large current flows among the plurality of components; and

a second ground connected to an accessory into which a current smaller than the large current flows,

wherein the power line includes:

a first power supply line that supplies power to the accessory into which the large current flows, and

a second power supply line that supplies power to an accessory into which a current smaller than the large current flows, and

wherein only the first power supply line among the first power supply line and the second power supply line is disposed in a space between the first ground line and the second ground line.

2. The vehicle circuit body according to claim 1, wherein,

the first ground line and the second ground line are disposed side by side on the same routing path so as to be arranged substantially parallel to each other and electrically insulated from each other.

3. A vehicle circuit body provided in a vehicle, the vehicle circuit body comprising:

a trunk line capable of being connected to a plurality of accessories mounted on the vehicle through branch lines or branch circuits,

wherein the trunk line comprises:

a power supply line capable of distributing and supplying electric power from a power supply mounted on the vehicle to the plurality of accessories, respectively;

a ground wire electrically connectable between a ground terminal of the power supply and the plurality of accessories; and

a communication line shared as a signal transmission line by the plurality of accessories each having a communication function,

wherein the ground line includes:

a first ground line connected to a component into which a large current flows among the plurality of components; and

a second ground connected to an accessory into which a current smaller than the large current flows,

wherein the first ground line and the second ground line are arranged side by side on the same routing path so as to be arranged substantially parallel to each other and electrically insulated from each other, and

wherein the second ground is disposed at an outer position that is farther from a body surface of the vehicle than the power supply line and the first ground.

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