Abstract:
A flexible wiring system for an electronic system includes a basic control circuit for controlling specific control circuits to obtain data from a sensor, a communication bus connected with the basic control circuit and the specific control circuits, and an intermediate distributing unit. The intermediate distributing unit includes plural first side connectors connectable with the basic control circuit and the specific control circuits, plural second side connectors connectable with sensors and actuators. The basic control circuit communicates signals with the specific control circuits via the communication bus so that the specific control circuits can control corresponding actuators according to the data obtained from corresponding sensors via the intermediate distributing unit.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
   The present application is based on and claims priority from Japanese Patent Application 2005-248948, filed Aug. 30, 2005, the contents of which are incorporated herein by reference. 
   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a flexible wiring system for connecting an extra electronic device with an electronic system of a vehicle. 
   2. Description of the Related Art 
   Electronic devices that are mounted in a vehicle are increasing year by year. Various electronic devices are mounted in various portions or areas of a vehicle, such as the engine compartment, the passenger compartment, the instrument panel and/or the roof liner area. Such electronic devices are connected with one or a plurality of control circuits (ECU) by specific wire harnesses and intermediate distributing units or junction boxes, as disclosed in JP-A-2000-253514. 
   There is a demand to connect an additional electronic device such as an actuator or a sensor with an extra terminal of an ECU, or a demand to connect the same kind of sensors respectively to a plurality of electronic control units. Because an intermediate distributing unit is disposed between the electronic control units and the additional electronic device, it is necessary to change a distributing board of the intermediate distributing unit, which causes additional cost and works. 
   Assuming that a new electronic control device such as an air condition control unit that requires one of electronic devices, such as an outside temperature sensor, for an electronic control unit that is already connected to the intermediate distributing unit, is to be connected to the same. It is more preferable for the two control units to commonly use the one of the electronic devices (e.g. outside temperature sensor) than to add the same electronic device if additional work or cost can be limited. 
   Assuming that an electronic device that is connected with the input side of an electronic control unit via a wire harness is to be changed to another electronic device that is to be connected with the input side of the same electronic control unit via another wire harness. It may be necessary to have new connectors and/or to modify the intermediate distributing unit. 
   SUMMARY OF THE INVENTION 
   Therefore, an object of the invention is to provide an improved wiring system for readily changing an electronic device that is connected with an electronic control unit via a wire harness to another electronic device that is to be connected with the same electronic control unit via another wire harness at a low cost. 
   According to a feature of the invention, a flexible wiring system includes a basic control circuit for controlling specific control circuits such as air condition control circuit to obtain data from an inputting device such as outside temperature, a communication bus connected with the basic control circuit and the specific control circuits and an intermediate distributing unit that includes plural first side connectors connectable with the basic control circuit and the specific control circuits, plural second side connectors connectable with the inputting devices and the outputting devices such as an air condition unit. The basic control circuit communicates signals with the specific control circuits via the communication bus so that the specific control circuits can control the outputting device according to the data obtained from the inputting device via the intermediate distributing unit. 
   According to the invention of the above flexible wiring system, the following embodiments may be further conceived: 
   (a) the intermediate distributing unit may connect the inputting devices with the basic control circuit, which delivers data obtained from the inputting devices to the specific control circuits via the communication bus; 
   (b) the intermediate distributing unit may connect the outputting devices with the basic control circuit, which controls the outputting device according to data obtained from the inputting devices; 
   (c) the intermediate distributing unit may include plural second side connectors which are respectively connectable with plural inputting devices, while the basic control circuit delivers the specific control devices a signal to select one of the second side connectors; 
   (d) the intermediate distributing unit may include a changeover switch disposed between one of the first side connectors, which is connected to one of the specific control circuits, and plural second side connectors, while the basic control circuit includes means for controlling the changeover switch to change over connection of one of the first side connectors from one to another of the second side connectors; and 
   (e) the intermediate distributing unit may include plural second side connectors, which are respectively connectable with plural inputting devices, and a changeover switch disposed between plural first side connectors, which are connectable with one of the inputting devices, and one of the second side connectors, while the basic control circuit includes means for controlling the changeover switch to change over connection of one of the first side connectors from one to another of the second side connectors, thereby to deliver the one of the specific control circuits a signal as to whether one of the inputting device is connected to a selected one of the first side connectors or not. 
   The above flexible wiring system may further include means, disposed in one of the specific control circuits, for providing an indication signal indicating one of the first side connectors to be connected. The means for controlling the changeover switch operates according to the indication signal. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Other objects, features and characteristics of the present invention as well as the functions of related parts of the present invention will become clear from a study of the following detailed description, the appended claims and the drawings. In the drawings: 
       FIG. 1  is a block diagram illustrating an overview of a hardware of a flexible wiring system according to the present invention applied to an electronic system for a vehicle; 
       FIG. 2  is a block diagram of a flexible wiring system according to the first embodiment of the invention; 
       FIG. 3  is a block diagram of a flexible wiring system according to a variation of the first embodiment of the invention; 
       FIG. 4  is a block diagram of a flexible wiring system according to the second embodiment of the invention; 
       FIG. 5  is a flow diagram of a control program to be applied to the flexible wiring systems shown in  FIG. 4 ; 
       FIG. 6  is a block diagram of a flexible wiring system according to the third embodiment of the invention; 
       FIG. 7  is a block diagram of a flexible wiring system according to a variation of the third embodiment of the invention; and 
       FIG. 8  is a flow diagram of a control program to be applied to the flexible wiring systems shown in  FIGS. 6 and 7 . 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   The present invention will be described with reference to the appended drawings hereafter. 
   A flexible wiring system according to the first embodiment of the invention will be described with reference to  FIGS. 1-3 . 
   As shown in  FIG. 1 , a vehicle electronic system  1  includes an intermediate distributing unit or a junction box  3 , plural inputting electronic devices DK(I), plural outputting electronic devices DK(O), a basic control unit  50 , an air conditioning ECU  60  and an inside rear view mirror ECU  70 , each of which control the outputting electronic devices DK(O) based on the signals of the inputting electronic devices DK(I) in preset manners. A flexible wiring system is mainly formed of the basic control unit  50  and the intermediate distributing unit  3 . 
   The intermediate distributing unit  3  has a connection changeover mechanism  150 , plural A-side connectors CNA and plural B-side connectors CNB. The inputting and outputting electronic devices DK(I), DK(O) are respectively connected by wires WA and WB with the basic control unit  50 , the air conditioning ECU  60 , and the inside rear view mirror  70  via the A-side and the B-side connectors CNA, CNB of the intermediate distributing unit  3 , input side connectors (CNI)  51 ,  52  and output side connectors (CNO)  53 ,  54 . 
   The wires WA and WB are respectively accommodated in wire harnesses HN that are respectively located at specific areas of a vehicle. The connection changeover mechanism  150  includes a wiring arrangement, plural changeover switches for connecting or disconnecting one or some of the A-side connectors CNA with or from any one or some of the B-side connectors. The wiring arrangement includes bus bars for supplying power and printed wires for supplying signals. The switches include relay switches (or a switch matrix) for switching power and analog switches (or a switch matrix) for switching signals. 
   The basic control unit(basic ECU)  50  includes a CPU  100 , a RAM  102 , a ROM  103 , a flash ROM  104 , an I/O port  105  and a communication I/F circuit  106 , which are connected each other by a bus bar in a usual manner. The flash ROM  104  stores device controlling application programs, a changeover control program, a communication software and connection setting data. The CPU  100 , RAM  102 , ROM  103  and the flash ROM  104 , the I/O port  105  are connected with a serial bus bar  135 , which connects to the air condition ECU  60  and the inside rear view mirror ECU  70 , via the communication I/F circuit  106 . The I/O port  105  is connected with B-side connectors CNB of the intermediate distributing unit  3  via the input side connectors (CNI)  51 ,  52  and the output-side connectors (CNO)  53 ,  54 . 
   As shown in  FIG. 2 , the flexible wiring system according to the first embodiment connects the input side of the basic ECU  50  with an outside temperature sensor  127 , the output side the air condition unit  60  with the air condition unit  45 , and the output side of an inside rear view mirror ECU  70  with an inside rear view mirror  48 . 
   The air condition ECU  60  controls the air condition unit  45  according to the signal sent from the outside temperature sensor  127 . The inside rear view mirror ECU  70  displays an outside temperature detected by the outside temperature sensor  127  on a portion of the inside rear view mirror  48 . 
   The intermediate distributing unit  3  includes a first A-side connector CNA( 1 ), a second A-side connector CNA( 2 ), a third A-side connector CNA( 3 ), a first B-side connector CNB( 1 ), a second B-side connector CNB( 2 ) and a third B-side connector CNB( 3 ). The first A-side connectors CNA( 1 ) is connected via the instrument panel wire harness  16  with the outside temperature sensor  127  and the first B-side connector CNB( 1 ). The second A-side connector CNA( 2 ) is connected via the engine compartment wire harness  17  with the air condition unit  45  and the second B-side connector CNB( 2 ). The third A-side connector CNA( 3 ) is connected via the floor wire harness  18  with the inside rear view mirror  48  and the third B-side connector CNB( 3 ). The first B-side connector CNB( 1 ) is connected with a second input side connector  52  of the basic ECU  50  via a wire harness  12 , the second B-side connector CNB( 2 ) is connected via a wire harness  13  with the output side connector  62  of the air condition ECU  60 , and the third B-side connector CNB( 3 ) is connected via a wire harness  14  with the output side connector  72  of the inside rear view mirror ECU  70 . 
   The temperature data of the outside temperature sensor  127  are taken by the basic ECU  50 , which delivers the temperature data via a communication bus (e.g.  135 ), as shown in arrows, to the air condition ECU  60  and the rear view mirror ECU  70 . Incidentally, each of the air condition ECU  60  and the rear view mirror ECU  70  sends an acknowledgement signal when it receives the temperature data. 
   As shown in  FIG. 3 , the flexible wiring system according to a variation of the first embodiment connects the input side of the basic ECU  50  with the outside temperature sensor  127 , the output side of the basic ECU  50  is connected with an outside temperature display panel  148 , and the output side of the air condition unit  60  with the air condition unit  45 , if the rear view mirror system that includes the ECU  70  and the inside rear view mirror  48  is omitted. 
   The first A-side connectors CNA( 1 ) is connected via the instrument panel wire harness  16  with the outside temperature sensor  127 , the second A-side connector CNA( 2 ) is connected via the engine compartment wire harness  17  with the air condition unit  45 , and the third A-side connector CNA( 3 ) is connected via the floor wire harness  18  with the outside temperature display panel  148 . The first B-side connector CNB( 1 ) is connected with the second input side connector  52  of the basic ECU  50  via the wire harness  12  to deliver the basic ECU  50  the signal of the outside temperature sensor  127 , the second B-side connector CNB( 2 ) is connected via the wire harness  13  with the output side connector  62  of the air condition ECU  60  to control the air condition unit  45  according to the outside temperature, the third B-side connector CNB( 3 ) connected via the wire harness  14  with a second output side connector  54  of the basic ECU  50  to display an outside temperature on the temperature display panel  148 . 
   The temperature data of the outside temperature sensor  127  are taken by the basic ECU  50 , which delivers the temperature data via a communication bus, as shown in an arrow, to the air condition ECU  60 . The air condition ECU  60  sends an acknowledgement signal when it receives the temperature data. 
   A flexible wiring system according to the second embodiment of the invention will be described with reference to  FIGS. 4 and 5 . 
   Assuming that an air condition system, which includes an air condition ECU  60 , an infrared light (IR) sensor  26  and an air condition unit  45 , is to be mounted in a vehicle. The intermediate distributing unit  3  includes the first A-side connectors CNA( 1 ) connected via the roof wire harness  15  with the infrared light sensor  26 , the second A-side connector CNA( 2 ), the third A-side connector CNA( 3 ), the fourth A-side connector CNA( 4 ), the fifth A-side connector CNA( 5 ), the sixth A-side connector CNA( 6 ), and the seventh A-side connector CNA( 7 ) connected with rear fog lamps  33  via the floor wire harness  18 . The second A-side connector CNA( 2 ), the third A-side connector CNA( 3 ) and the fourth A-side connector CNA( 4 ) are respectively connected through the instrument panel wire harness  16  with an inside air temperature sensor  27 , a rear fog lamp switch  128  and a head lamp switch  129  which is connected via the instrument panel wire harness  16  with the air condition ECU  60 , which is connected via the instrument panel wire harness  16  with a head lamp control circuit disposed in the basic control unit  50  The fifth A-side connector CNA( 5 ) and the sixth A-side connector CNA( 6 ) are respectively connected via the engine compartment wire harness  17  with the air condition unit  45 , and head lamps  31 . 
   The intermediate distributing unit  3  further includes the first B-side connector CNB( 1 ), the second B-side connector CNB( 2 ), the third B-side connector CNB( 3 ), the fourth B-side connector CNB( 4 ), the fifth B-side connector CNB( 5 ) and the sixth B-side connector CNB( 6 ). The first B-side connector CNB( 1 ) is connected, via the wire harness  11  and the input side connector  61 , with a room temperature control circuit  262  of the air condition ECU  60 . The first B-side connector CNB( 1 ) is also connected with one of a pair of the first and the second A-side connectors CNA( 1 ), CNA( 2 ) via a changeover switch  28 . The second B-side connector CNB( 2 ) and the third B-side connector CNB( 3 ) respectively connect the second and third A-side connectors CNA( 2 ) and CNB( 3 ) via the wire harness  12  with the second input side connector  52  of the basic control unit  50 . The fourth B-side connector CNB( 4 ) and the fifth B-side connector CNB( 5 ) respectively connect an output side connector  62  of the air condition ECU  60  and the first output side connector  53  of the basic ECU  50  with the fifth and sixth A-side connectors CNA( 5 ) and CNA( 6 ). The fifth B-side connector CNB( 5 ) connects the second output side connector  54  of the basic ECU  50  with the seventh A-side connector CNA( 7 ). Incidentally, the first input side connector  51  may be connected with some other B-side connector CNB (not shown) via another wire harness. 
   The changeover program of the control unit  50  operates as shown in  FIG. 5 . The control unit  50  receives from the air condition ECU  60 , via the communication bus  135  shown in  FIG. 1 , information about which of the devices (IR sensor  26  or the inside air temperature sensor  27 ) is to be connected with the input side connector  61  at S 51 . For example, the changeover control circuit  57  controls the changeover switch  28  to connect the first B-side connector CNB( 1 ), which is connected with the input side connector  61 , with the first A-side connector CNA ( 1 ), which is connected with the IR sensor  26 , instead of the second A-side connector CNA( 2 ), which is connected with the inside air temperature sensor  27  at S 52 . When the changeover operation is completed, a completion signal is sent to the air condition ECU  60  at S 53 . 
   A flexible wiring system according to the fourth embodiment of the invention will be described with reference to  FIGS. 6-8 . 
   The flexible wiring system is to connect an inside rear view mirror ECU  70  with an inside rear view mirror  48  in addition to the air condition ECU  60 , an outside temperature sensor  127  and the air condition unit  45 , which are mounted in the vehicle as a standard equipment. 
   The air condition ECU  60  controls the air condition unit  45  according to the signal sent from the outside temperature sensor  127 . The inside rear view mirror ECU  70  displays an outside temperature detected by the outside air temperature sensor  127  on a portion of the inside rear view mirror  48 . 
   The intermediate distributing unit  3  includes the first A-side connectors CNA( 1 ) connected via the instrument panel wire harness  16  with the outside temperature sensor  127 , the second A-side connector CNA( 2 ) connected via the engine compartment wire harness  17  with the air condition unit  45 , the third A-side connector CNA( 3 ) connected via the floor wire harness  18  with the inside rear view mirror  48 . The intermediate distributing unit  3  further includes the first B-side connector CNB( 1 ) connected with an input side connector  71  of the inside rear view mirror ECU  70  via the wire harness  11 , the second B-side connector CNB( 2 ) connected via the wire harness  12  with the input side connector  61  of the air condition ECU  60 . The third B-side connector CNB( 3 ) connects, via the wire harness  13  and the output side connector  62 , the air condition ECU  60  with the second A-side connector CNA( 2 ) to control the air condition unit  45 , and the fourth B-side connector CNB( 4 ) connects, via the output side connector  72 , the inside rear view mirror ECU  70  with the third A-side connector CNA( 3 ) to display an outside temperature on a portion of the inside rear view mirror  48 . 
   The changeover mechanism  150  also includes a changeover switch  29  disposed between the first A-side connector CNA( 1 ) and a pair of the first and the second B-side connectors CNB( 1 ), CNB( 2 ). When the inside rear view mirror ECU  70  and the inside rear view mirror  48  are mounted as an optional system, the outside temperature sensor  127 , which is already connected to the input side of the air condition control ECU  60 , is not directly connected to the input side of the inside rear view mirror ECU  70  via the first B-side connector CNB( 1 ). The data of the outside temperature sensor  127  taken by the air condition control ECU  60  is transmitted to the inside rear view mirror ECU  70  via a communication bus to display an outside temperature. 
   For this purpose, the changeover control circuit  57  controls the changeover switch  29  to connect the second B-side connector CNB( 2 ), which is connected with the input side connector  61 , with the second A-side connector CNA ( 2 ), which is connected with the outside temperature sensor  127 . When the changeover operation is completed, a completion signal is sent to the air condition ECU  60 . 
   If a vehicle is sold in a cold district where the air conditioning is not usually necessary, the second B-side terminal CNB( 2 ), the first A-side connector CNA( 1 ), the third B-side connector ( 3 ) and the second A-side connector CNA( 2 ) are reserved for the outside temperature sensor  127 , the air condition ECU  60  and the air condition unit  45  to meet the user&#39;s demand for the air condition system, as shown in  FIG. 7 . In this case, the changeover switch  29  connects the first B-side connector CNB( 1 ) with the first A-side connector CNA( 1 ) so that the outside temperature sensor  127  can directly connect with the inside rear view mirror ECU  70 . 
   The changeover program of the control unit  50  operates as shown in  FIG. 8 . 
   At first, the outside temperature sensor  127  is specified at S 101 . Then, the inside rear view mirror ECU  70  as an additional ECU that requires the data detected by the outside temperature sensor  127  is specified at S 102 . Subsequently, whether the additional ECU is one or not is examined at S 103 . 
   If the result of the examination is Yes, the changeover switch  29  is controlled to connect the outside temperature sensor  127  with the inside rear view mirror ECU  70  at S 104 , and the completion of the connection is reported to the inside rear view mirror ECU  70  at S 105 . After an acknowledgement signal is received from the inside rear view mirror ECU  70  at S 106 , the program ends. 
   If the result of the examination at S 103  is No, the changeover switch  29  is controlled to connect the outside temperature sensor  127  with the air condition ECU at S 107 , and the completion of the connection is reported to the air condition ECU  60  and instructs the same to deliver the inside rear view mirror ECU  70  the data detected by the outside temperature sensor  127  at S 108 . Thereafter, the step goes to S 106 . 
   In the foregoing description of the present invention, the invention has been disclosed with reference to specific embodiments thereof. It will, however, be evident that various modifications and changes may be made to the specific embodiments of the present invention without departing from the scope of the invention as set forth in the appended claims. Accordingly, the description of the present invention is to be regarded in an illustrative, rather than a restrictive, sense.