Wiring structure for instrument panel of vehicle

A plurality of sub-modules are constituted by connecting a plurality of electronic units among electronic units for an instrument panel to a common control unit. A control unit for each sub-module is connected to a common instrument panel harness to permit multiple communication among the control units.

BACKGROUND OF THE INVENTION
 The present invention relates to a wiring structure for an instrument panel
 of a vehicle.
 Hitherto, wiring for an instrument panel has been performed such that
 electronic units are disposed in a multiplicity of portions of the
 instrument panel. Then, a wire harness for an instrument panel stretched
 in the form of a net is disposed on the reverse side of the instrument
 panel. Moreover, connectors provided for each end of the wire harness and
 connectors of the electronic units are sequentially connected to each
 other.
 The foregoing wiring structure must be formed such that all of the
 operations for mounting each electronic unit on the instrument panel and
 the operations for connecting each electronic unit to the wire harness are
 performed on a manufacturing line for only the instrument panel. The
 number of electronic units provided for the instrument panel has yearly
 been increased. Therefore, the amount of labor required to perform the
 operations for mounting the electronic units and the wiring operations
 have been enlarged. Thus, assembly cannot easily be performed. Hence it
 follows that an excessively long time is required to manufacture the
 instrument panel on the manufacturing line. As a result, automatization of
 the assembly and improvement in the efficiency have undesirably been
 inhibited.
 As the number of the electronic units is increased, the shape of the wire
 harness for the instrument panel connecting the electronic units becomes
 more complicated. Also the weight of the wire harness has excessively been
 enlarged. Therefore, the wire harness cannot easily be handled.
 When the types of the electronic units and the layout of the electronic
 units are changed to realize a required grade, the wire harness for the
 instrument panel must be changed to correspond to the type and layout.
 Thus, there arises a problem in that the conventional technique is
 uneconomical and adaptation cannot easily be permitted.
 SUMMARY OF THE INVENTION
 In view of the foregoing, an object of the present invention is to provide
 a wiring structure for an instrument panel of a vehicle with which wiring
 can be simplified, the weight of the wiring can be reduced and the wiring
 operation can be flexibly adapting to changes in the grade or the like.
 As a means for solving the foregoing problems, according to one aspect of
 the present invention, there is provided a wiring structure for an
 instrument panel of a vehicle arranged to be provided for a plurality of
 electronic units disposed in the instrument panel of a vehicle, the wiring
 structure for an instrument panel of a vehicle comprising: a plurality of
 sub-modules constituted by connecting a plurality of electronic units for
 the instrument panel to a common control unit, wherein the control units
 of the sub-modules are connected to a common wire harness so that multiple
 communication is performed among the plural control units.
 The foregoing structure permits multiple communication to be performed
 between the control units for controlling the plural electronic units in
 the sub-modules. Thus, a communication network connecting the electronic
 units of all of the sub-modules is formed. As compared with the
 conventional structure in which each electronic unit is individually
 connected to the wire harness, the structure according to the present
 invention is able to considerably simplify the shape and structure of the
 wire harness. Moreover, the wiring operation can be facilitated. When the
 types and layout of the electronic units to be adapted to a required grade
 are changed, adaptation can be performed by simply changing the
 sub-module. Thus, the adapting operation can be facilitated. Moreover, a
 common wire harness can be employed.
 Each sub-module and the wire harness can directly be connected to each
 other through electric wires or the like. A structure may be employed in
 which a connector is provided for each sub-module, connectors which are
 detachably connected to the connectors of the sub-modules are provided for
 the wire harness and the connections of the connectors enable the control
 units of the sub-modules to be connected to one another such that multiple
 communication is permitted. In the foregoing case, the sub-module can
 easily be changed.
 A structure may be employed in which an electric junction box which is
 connected to electronic units for a vehicle except for the electronic
 units for the instrument panel is connected to the wire harness so that
 multiple communication is performed between a control unit of the
 electronic junction box and the control unit of at least one sub-module.
 Thus, a wide network including the other electronic units as well as the
 electronic units for the instrument panel can be formed with a simple
 structure.
 When the wire harness is allowed to pass close by the instrument panel so
 as to be arranged in the widthwise direction of the vehicle, the electric
 junction box is connected to each of two ends of the wire harness and the
 control unit of each sub-module is connected to an intermediate portion of
 the wire harness, the wiring structure using the wire harness can be
 simplified and rationalized.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
 An embodiment of the present invention will now be described with reference
 to the drawings.
 An engine computer 12 for controlling an engine is provided for an engine
 room 10 formed in the front portion of the vehicle shown in FIG. 1. An
 electric junction box (a joint box) 16 is provided for the front portion
 of each of right-hand and left-hand portions in a cabin 14. The electric
 junction box 16 includes an individual computer (a control unit). The
 foregoing computer is connected to the engine computer 12 and a door
 computer 18 provided for each door 17 such that multiple communication is
 permitted.
 An instrument panel 20 structured as shown in FIG. 2 is disposed in the
 front portion of the cabin 14. Moreover, an instrument-panel wire harness
 (hereinafter called "instrument panel harness") 22 is disposed on the
 reverse side of the instrument panel 20. The instrument panel harness 22
 has a simple shape extending in the widthwise direction of the vehicle in
 substantially a straight line. The two ends of the instrument panel
 harness 22 are connected to the electric junction boxed 16. A plurality
 (four in the drawing) of branch lines are branched at intermediate
 positions of the instrument panel harness 22. Connectors 24, 25, 26 and 27
 are disposed at the ends of the branched lines.
 Among electronic units provided for the instrument panel 20, the air
 conditioner and electronic units disposed adjacent to the air conditioner
 are gathered as an air-conditioner sub-module 30 (that is, formed into a
 module) Similarly, electronic units provided for a center cluster disposed
 in the central portion of the instrument panel are gathered as a center
 cluster sub-module 40. Electronic units disposed adjacent to the steering
 wheel are gathered as a steering sub-module 50. Electronic units, such as
 meters and electronic units disposed adjacent to the meters, are gathered
 as a meter sub-module 60. The sub-modules 30, 40, 50 and 60 are provided
 with corresponding connectors 30B, 40B, 50B and 60B. The connectors 30B,
 40B, 50B and 60B are connected to the connectors 24, 25, 26 and 27 of the
 instrument panel harness 22. Thus, the sub-modules 30, 40, 50 and 60 and
 the right and left electric junction boxes 16 are integrated through the
 instrument panel harness 22.
 The specific structures of the sub-modules 30, 40, 50 and 60 will now be
 described.
 Air-conditioner sub-Module 30 is shown in FIG. 3.
 The air-conditioner sub-module 30 incorporates a housing 30A. The connector
 30B is secured to the housing 30A. Moreover, the housing 30A accommodates
 an air-conditioner computer (a control unit) 31, a cooling-temperature
 sensor 32, a blowing-direction changing servo motor 33, an
 assistant-seat-side temperature adjustment servo motor 34, a
 driver's-seat-side temperature adjustment servo motor 35, an insolation
 sensor 36 and an automatic-light sensor 37.
 An air-conditioner computer 31 is connected to each terminal of the
 connector 30B through a power supply line and a signal line. The
 cooling-temperature sensor 32, the blowing-direction changing servo motor
 33, the assistant-seat-side temperature adjustment servo motor 34, the
 driver t s-seat-side temperature adjustment servo motor 35, the insolation
 sensor 36 and the automatic-light sensor 37 are connected to the common
 air-conditioner computer 31 through the power supply line and the signal
 line so as to be integrated and controlled by the air-conditioner computer
 31. When the connector 30B and the connector 24 of the instrument panel
 harness 22 are connected to each other, electric power is supplied from a
 battery to sequentially pass through the electric junction box 16, the
 instrument panel harness 22 and the connectors 24 and 30B so as to be
 supplied to the air-conditioner computer 31. Then, electric power is
 supplied from the air-conditioner computer 31 to the other electronic
 units 32 to 37. Moreover, multiple communication can be performed among
 the air-conditioner computer 31 and computers of the other sub-modules 40,
 50 and 60 and the electric junction box 16.
 Center Cluster Sub-Module 40 is shown in FIG. 4.
 The center cluster sub-module 40 incorporates a housing 40A. The connector
 40B is secured to the housing 40A. The housing 40A accommodates a
 center-cluster computer (a control unit) 41, an audio switch 42 (the
 switch or the body of the audio unit), an air-conditioner switch 43, a
 hazard switch 44, a clock 45, a temperature sensor 46, a cigarette lighter
 47, an ashtray illumination 48 and an air-cleaner switch 49.
 The center-cluster computer 41 is connected to each terminal of the
 connector 40B through the power supply line and the signal line. The audio
 switch 42, the air-conditioner switch 43, the hazard switch 44, the clock
 45, the temperature sensor 46, the cigarette lighter 47, the ashtray
 illumination 48 and the air-cleaner switch 49 are connected to the common
 center-cluster computer 41 through the power supply line and the signal
 line so as to be integrated and controlled by the center-cluster computer
 41. When the connector 40B and the connector 25 of the instrument panel
 harness 22 are connected to each other, electric power is supplied from
 the battery to sequentially pass through the electric junction box 16, the
 instrument panel harness 22 and the connectors 25 and 40B so as to be
 supplied to the center-cluster computer 41. Then, electric power is
 supplied from the center-cluster computer 41 to the other electronic units
 42 to 49. Moreover, multiple communication can be performed among the
 center-cluster computer 41 and the computers of the other sub-modules 30,
 50 and 60 and the electric junction box 16.
 A connector 40C is secured to the housing 40A. Also the connector 40C is
 connected to the center-cluster computer 41. A connector 71 provided for a
 console sub-harness 70 which is individual from the instrument panel
 harness 22 can be connected to the connector 40C. In the connected state,
 also electronic units, such as an accessory socket 72, an ECT switch 73,
 an O/D switch 74 and a shift-lock computer 75, are connected to the
 center-cluster computer 41 through the console sub-harness 70. Also the
 foregoing electronic units 72 to 75 are integrated and controlled by the
 center-cluster computer 41.
 As described above, the present invention may be structured such that a
 portion of the electronic units constituting the sub-modules are disposed
 on the outside of the housings.
 Steering Sub-Module 50 is shown in FIG. 5
 The steering sub-module 50 incorporates a housing 50A. The connector 50B is
 secured to the housing 50A which accommodates a steering computer (a
 control unit) 51, an ignition switch 52, a combination switch 53 including
 a wiper switch and a light control switch, a key illumination 54 and a
 key-lock cancellation switch 55.
 The steering computer 51 is connected to each terminal of the connector 50B
 through the power supply line and the signal line. The ignition switch 52,
 the combination switch 53, the key illumination 54 and the key-lock
 cancellation switch 55 are connected to the common steering computer 51
 through the power supply line and the signal line so as to be integrated
 and controlled by the steering computer 51. When the connector 50B and the
 connector 26 of the instrument panel harness 22 are connected to each
 other, electric power supplied from the battery sequentially passes
 through the electric junction box 16, the instrument panel harness 22 and
 connectors 26 and 50B so as to be supplied to the steering computer 51.
 Then, electric power is supplied from the steering computer 51 to the
 other electronic units 52 to 55. Moreover, multiple communication can be
 performed among the steering computer 51 and the computers of the other
 sub-modules 30, 40 and 60 and the electric junction box 16.
 A connector 50C is secured to the housing 50A. A driver's-seat air bag 56
 is connected to the connector 50C. On the other hand, a connector 28
 individual from the connector 26 is provided for the instrument panel
 harness 22 so that the connection between the connector 28 and the
 connector 50C is permitted. In the foregoing connected state, an air-bag
 signal is directly (that is, passing through the steering computer 51 is
 inhibited) input from the instrument panel harness 22 to the driver's-seat
 air bag 56 through the connectors 28 and SOC. Thus, the driver's-seat air
 bag 56 can be operated.
 As described above, the present invention may be structured such that the
 electronic units (that is, the electronic units except for the electronic
 units constituting the sub-modules) which are not integrated by the
 control unit (the steering computer 51 in the case shown in the drawing)
 are accommodated in the housing 50A together with the electronic units
 constituting the sub-modules.
 Meter Sub-Module 60 is shown in FIG. 6.
 The meter sub-module 60 incorporates a housing 60A. The connector 60B is
 secured to the housing 60A which accommodates a meter computer (a control
 unit) 61, a meter body 62, an odo/trip changing switch 63 and a luminance
 changing switch 64.
 The meter computer 61 is connected to each terminal of the connector 60B
 through the power supply line and the signal line. The meter body 62, the
 odo/trip changing switch 63 and the luminance changing switch 64 are
 connected to the common meter computer 61 through the power supply line
 and the signal line so as to be integrated and controlled by the meter
 computer 61. When the connector 60B and the connector 27 of the instrument
 panel harness 22 are connected to each other, electric power is supplied
 from the battery so as to sequentially pass through the electric junction
 box 16, the instrument panel harness 22 and the connectors 27 and 60B so
 as to be supplied to the meter computer 61. Then, electric power is
 supplied from the meter computer 61 to the other electronic units 62 to
 64. Moreover, multiple communication among the meter computer 61 and the
 computers of the sub-modules 30, 40 and 50 and the electric junction box
 16 is possible.
 Among the above-mentioned sub-modules, the specific wiring structure in the
 center cluster sub-module 40 will now be described with reference to FIG.
 7.
 As shown in FIG. 7, electric power supplied from the instrument panel
 harness 22 through the connectors 25 and 40B is supplied to only the
 center-cluster computer 41. On the other hand, electric power is supplied
 from the center-cluster computer 41 to all of the other electronic units
 42 to 49 in the other housings and the electronic units adjacent to
 console sub-harness 40C. Supply of electric power may be performed without
 passing through the center-cluster computer 41. Grounding is performed
 such that passing through the center-cluster computer 41 is inhibited and
 direct passing through the connectors 40B and 25 is performed.
 All of the electronic units and the connector 40C except for the
 center-cluster computer 41 and the hazard switch 44 are connected to the
 center-cluster computer 41 through the signal lines. Thus, communication
 of signals among the foregoing electronic units and electronic units of
 the console sub-harness 70 connected to the connector 40C is permitted.
 The center-cluster computer 41 is connected to a multiple communication
 line in the instrument panel harness 22 through the multiple communication
 line in the module and the connectors 40B and 25. Therefore, multiple
 communication among the center-cluster computer 41 and the computers 31,
 51 and 61 of the other sub-modules and the computer in the electric
 junction box 16 is permitted.
 The above-mentioned structure enables wiring in the vicinity of the
 instrument panel 20 to be performed by, for example, the following
 procedure.
 (1) The sub-modules 30 to 60 are previously assembled on the outside of the
 line for manufacturing the instrument panel. The layout of the electronic
 units of the sub-modules 30 to 60 is previously made to be the same as the
 final layout when the foregoing electronic units are mounted on the
 instrument panel 20.
 (2) The electric junction box 16 and the instrument panel harness 22 are
 disposed with respect to the instrument panel 20.
 (3) The sub-modules 30, 40, 50 and 60 are mounted on the instrument panel
 20. Moreover, the connectors 24, 25, 26 and 27 of the instrument panel
 harness 22 are connected to the connectors 30B, 40B, 50B and 60B of each
 sub-module. Therefore, only four connectors must be connected when the
 connection among the sub-modules and the instrument panel harness 22 is
 established. The operations for connecting the other connectors, that is,
 the connection between the connector 40C of the center cluster sub-module
 40 and the connector 71 of the console sub-harness 70, that between the
 connector 50C of the steering sub-module 50 and the connector 28 of the
 instrument panel harness 22 and those between the connectors of the other
 electronic units and the connectors of the harness are established so that
 wiring in the vicinity of the instrument panel 20 is completed.
 The thus-constituted wiring structure permits the mutual multiple
 communication among the sub-module computers 31, 41, 51 and 61 of the
 sub-module and the computer in the electric junction box 16 to be
 performed. Moreover, communication of signals among the controlling
 computer in each sub-module and the other electronic units is performed.
 Thus, communication among the electronic units can be performed similarly
 to the conventional structure. The specific state of the communication
 will now be described.
 (1) An example of Communication between One Sub-Module:
 In the air-conditioner sub-module 30 shown in FIG. 3, a detection signal
 supplied from the cooling-temperature sensor 32 is input to the
 air-conditioner computer 31. In response to the detection signal,
 feed-back control signals are output from the air-conditioner computer 31
 to the temperature adjustment servo motors 34 and 35.
 (2) An example is shown in FIG. 8A of Communication Between Sub-Modules.
 when, for example, the temperature changing switch of the air-conditioner
 switch 43 of the center cluster sub-module 40 is operated, a
 temperature-changing instruction signal is input to the center-cluster
 computer 41. The center-cluster computer 41 transmits a multiple signal to
 the air-conditioner computer 31 of the air-conditioner sub-module 30
 through the multiple communication line in the instrument panel harness
 22. In response to this, the air-conditioner computer 31 outputs a motor
 rotating signal to each of the assistant-seat-side temperature adjustment
 servo motor 34 and the driver's-seat-side temperature adjustment servo
 motor 35. Thus, the temperature adjustment operation is performed. As a
 result, the temperature adjustment servo motors 34 and 35 of the body of
 the air conditioner are operated in synchronization with the operation of
 the air-conditioner switch 43.
 Other examples of the multiple communication between the sub-module
 computers are exemplified by an operation for turning on an illumination
 lamp of the meter sub-module 60 (or the center cluster sub-module 40) in
 synchronization with an operation for switching on the lamp switch of the
 combination switch 53 of the steering sub-module 50. Another operation is
 included with which an indicator lamp of the meter body 62 is turned on in
 synchronization with the operation for switching on a cruise control
 switch of the combination switch 53 or a shift pattern switch (omitted in
 FIG. 4) of the center cluster sub-module 40.
 (3) An example of Transmission from Sub-Module to Electric Junction Box 16
 is shown in FIG. 8B: When the air-cleaner switch 49 of the center cluster
 sub-module 40 is switched on, a switching signal is input to the
 center-cluster computer 41. The center-cluster computer 41 transmits a
 multiple signal to the computer in the electric junction box 16 through a
 multiple communication line in the instrument panel harness 22. In
 response to this, the computer in the electric junction box outputs a
 control signal to the air cleaner 80 to operate the air cleaner 80. As a
 result, the air cleaner 80 is operated in synchronization with the
 operation of the air-cleaner switch 49.
 Other examples are exemplified by an operation for rotating the wiper motor
 in synchronization with the operation of the combination switch 53 of the
 steering sub-module 50. An operation is included with which a starter
 motor is rotated in synchronization with the operation of the ignition
 switch 52.
 (4) An example of Transmission from Electric Junction box 16 to a
 Sub-Module is shown in FIG. 8C: the engine computer 12 receives any one of
 a variety of detection signals, such as a car-speed detection signal, a
 detection signal indicating the number of revolution of the engine, a
 detection signal indicating a residual quantity of gasoline or a detection
 signal indicating the water temperature of the engine. Thus, the engine
 computer 12 inputs an information signal concerning the contents of the
 detection to the computer in the electric junction box 16. In response to
 this, the foregoing electric junction box computer transmits a multiple
 signal to the meter computer 61 of the meter sub-module 60 through the
 multiple communication line in the instrument panel harness 22. The meter
 computer 61 displays a result of the detection by operating an actuator of
 the meter body 62 or by turning on any one of display lamps (a lamp for
 displaying the shift position, check engine, ABS, a seat belt, a half
 door, a parking brake, the battery, the air bag, the high beam or the lamp
 disconnection detection).
 Also supply of electric power to the other electronic units is performed
 through the battery, the electric junction box 16, the instrument panel
 harness 22, each of the sub-module computers 31, 41, 51 and 61 and each
 electronic unit.
 The foregoing strength attains the following effects.
 With respect to the shape and structure of the instrument panel harness 22,
 the conventional wiring structure is arranged such that the shape of the
 instrument panel harness 22 is the branched structure for each electronic
 unit. Moreover, terminal connectors must be provided by the number
 corresponding to the number of the electronic units. Therefore, if a large
 number of electronic units must be provided, the shape and structure of
 the instrument panel harness 22 become too complicated. What is worse, the
 weight of the instrument panel harness 22 is enlarged excessively to
 easily treat the instrument panel harness 22. On the other hand, the
 present invention's wiring configuration, as shown in FIG. 10, is
 structured such that the plural electronic units concerning one another is
 integrated into sub-modules 30 to 60. Moreover, the network is formed by
 permitting the multiple communication. Hence the number of branched lines
 and connectors required for the instrument panel harness 22 can
 significantly be reduced. For example, compare the structure shown in FIG.
 9 with that shown in FIG. 10. Therefore, the shape of the harness 22
 according to the invention can considerably be simplified and the overall
 weight can be reduced. As a result, the instrument panel harness 22 can
 more easily be handled.
 With respect to the wiring operation, the conventional wiring structure,
 of, for example, FIG. 9. requires operations connecting the connectors of
 the various electronic units and the connectors of the instrument panel
 harness 22 to one another on the manufacturing line according to the
 corresponding number of electronic units as a rule. Therefore, an
 excessive amount of labor is required. On the other hand, the wiring
 operation of the present invention reduces the manufacturing labor by
 unifying and integrating the electronic unit sub-modules with the
 respective sub-module computers 31, 41, 51 and 61 before assembly of the
 instrument panel. Thus, a simple operation is required on the
 manufacturing line with which the instrument-panel-side connectors 24 to
 27 and the connectors of the sub-modules are connected to one another.
 Hence it follows that a wide communication network can quickly be formed.
 As a result, the manufacturing efficiency can considerably be improved.
 Therefore, handling of the instrument panel harness 22 can significantly
 be facilitated.
 With respect to the versatility of the instrument panel harness 22, when
 the types or the layout of the electronic units for the instrument panel
 20 is changed to be adapted to a required grade, the conventional
 structure requires changing the shape and structure of the instrument
 panel harness 22 to adapt the electronic units to the types and layout
 desired. Therefore, several instrument panel harnesses 22 must be provided
 according to the types or grade desired. As a result, the conventional
 wiring structure is not economical. On the other hand, the wiring
 structure shown in FIGS. 1 to 8 enables adaptation to the grade to be
 performed easily by only changing the sub-modules. Therefore, a common
 instrument panel harness 22 can always be employed. Hence it follows that
 the present invention is significantly more economical and adaptable than
 the conventional wiring structure and the mass production of the invention
 can easily be performed.
 The embodiment of the present invention is not limited to the foregoing
 type. The following examples may be employed.
 (1) The present invention permits omission of any one of the foregoing
 sub-modules regardless of the types and number of sub-modules. Moreover,
 other sub-modules (for example, a glove-box sub-module and the air-bag
 sub-module) may be added. Also the electronic units constituting each
 sub-module may arbitrarily be selected.
 (2) The connection between each sub-module and the electric junction box
 may arbitrarily be omitted. If the omitted connection is employed to
 permit multiple communication between each sub-module and the electric
 junction box, the network between the electronic unit for the instrument
 panel and the other electronic unit can be simplified. Hence it follows
 that a further satisfactory effect can be obtained.
 (3) The present invention permits arbitrary determination of the shape and
 wiring region of the instrument panel harness 22. The instrument panel
 harness 22 according to the present invention is arranged in the widthwise
 direction of the vehicle. The arrangement is performed in the present
 invention such that the right and left electric junction boxes 16 are
 connected to each other and the sub-modules are connected to the
 intermediate positions of the instrument panel harness 22. Thus, the
 communication network among the sub-modules and the electric junction
 boxes can be formed with a simple structure.
 As described above, according to the present invention, there is provided
 the wiring structure for an instrument panel of a vehicle having a
 plurality of electronic units disposed in the instrument panel, the wiring
 structure for an instrument panel of a vehicle comprising: a plurality of
 sub-modules constituted by connecting a plurality of electronic units for
 the instrument panel to a common control unit, wherein the control units
 of the sub-modules are connected to a common wire harness so that multiple
 communication is performed among the plural control units. Therefore,
 effects can be attained in that the wiring can be simplified, weight
 reduction of the wiring structure is permitted and the wiring operation of
 the various units and sub-modules can be facilitated. Moreover, flexible
 adaptation of the wiring harness structure to changes is permitted.