Abstract:
A checking method is described for a wiring harness having first sub-harnesses and second sub-harnesses in which the first sub-harness has a first press-fit terminal joined to each end of a first electrical cable, and the first sub-harness has a first isolator holding the first press-fit terminal and the second sub-harness has a second press-fit terminal, a crimp terminal, a connector housing for accommodating the crimp terminal, a second isolator supporting the second press-fit terminal and wherein a second electrical cable connects the second press fit terminal and the crimp terminal at opposite ends. The checking method, which is effective upon layering of the first and second isolators includes the conduct of decision steps for determining acceptance or rejection of the individual sub-harnesses after assembly thereof and a final decision step for determining acceptance or rejection of the completed wiring harness layering following of the isolators of the first and second sub-harness.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a checking method of a wiring harness arranged in a mobile unit such as a motor vehicle. 
     2. Related Art 
     A motor vehicle has a wiring harness for supplying power to electrical appliances such as various lamps and motors from a battery. A conventional wiring harness includes a plurality of electrical cables, a plurality of terminals each fitted to an end of each electrical cable, connector housings accommodating the terminals, etc. 
     An ordinary or high grade car has an increasing number of on-vehicle electronics components, which requires hundreds to thousands of electrical cables. Thus, a wiring harness for such a car tends to have an increasing number of electrical cables. 
     A plurality of sub-harnesses are pre-assembled and each wiring harness is obtained by assembling the sub-harnesses. The sub-harness has a plurality of electrical cables, terminals each connected to an end of the electrical cable, and a connector housing accommodating some of the terminals. The sub-harness may have terminals which are not received in the connector housing to be an unprotected state. 
     An electrical continuity check of the wiring harness will be carried out after combination of the sub-harnesses when the sub-harnesses has the unprotected terminals, due to the circuit incompleteness of the sub-harnesses. In the electrical continuity check of the wiring harness, the terminals each are checked in electrical continuity with the other terminals to determine acceptance or rejection of the wiring harness. Such checking methods of the wiring harness have been carried out through the following sequential steps. 
     Each terminal of the wiring harness is selected sequentially to supply a voltage, while the other terminals of the wiring harness are checked in voltage thereof. Thereby, the electrical continuity relationship of the terminals can be known. 
     The obtained electrical continuity relationship of the terminals is compared with a pre-designed electrical continuity pattern of the wiring harness. Thereby, acceptance or rejection of the wiring harness has been determined, and an incorrect continuity point of the wiring harness could be found, if present. 
     The aforementioned conventional checking method of the wiring harness applies a voltage to each terminal sequentially to measure the other terminals in voltage. Thus, the voltage application is repeated for the total number of the terminals, so that it disadvantageously takes a long time to check the wiring harness since the electrical cables and terminals are increasing in number. 
     For example, it takes a time T that a voltage is applied to one of the terminals of the wiring harness to measure the other terminals in voltage. When the wiring harness has 3,000 terminals, it requires a time of T×3,000 for checking electrical continuity of the terminals. 
     Moreover, it is necessary to transfer the wiring harness from its production line to a checking apparatus. Thereby, a long time is required to complete the wiring harness, causing a decreased productivity of the wiring harness. 
     In addition, it is difficult to know which assembling step of the wiring harness has been incorrect, since the electrical continuity of the terminals is checked after the completion of the wiring harness. 
     Furthermore, when an incorrect continuity point of a wiring harness is recognized, another wiring harness or an intermediate product which includes the same incorrectness would have been assembled. This tends to cause a further decreased productivity of the wiring harnesses. 
     SUMMARY OF THE INVENTION 
     Therefore, an object of the invention is to provide a checking method of a wiring harness, in which an appropriate productivity of the wiring harness is achieved. 
     For achieving the object, a checking method according to the present invention is provided for determining acceptance or rejection of a wiring harness having a plurality of first sub-harnesses and a plurality of second sub-harnesses. The first sub-harnesses has a plurality of electrical cables, a plurality of first press-fit terminals, and a first isolator. The first press-fit terminal is joined to each end of the first electrical cable. The first isolator holds the first press-fit terminals positioned at one end of the first sub-harness. The second sub-harness has a plurality of second electrical cables, a plurality of second press-fit terminals, a plurality of crimp terminals, a connector housing for accommodating the crimp terminals, and a second isolator supporting the second press-fit terminals. The second press-fit terminal is connected to one end of the second electrical cable. The crimp terminal is connected to the other end of the second electrical cable. When any of the first and second isolators are layered, the press-fit terminals held by different ones of the isolators can be connected to one another. The method includes: 
     a first decision step for determining acceptance or rejection of the first sub-harness after assembling of the first sub-harness, 
     a second decision step for determining acceptance or rejection of the second sub-harness after assembling of the second sub-harness, and 
     a third decision step for determining acceptance or rejection of the wiring harness after layering the isolators of the first and second sub-harnesses to complete the wiring harness. 
     a first decision step for determining acceptance or rejection of the first sub-harness after assembling of the first sub-harness, 
     a second decision step for determining acceptance or rejection of the second sub-harness after assembling of the second sub-harness, and 
     a third decision step for determining acceptance or rejection of the wiring harness after layering the isolators of the first and second sub-harnesses to complete the wiring harness. 
     Preferably, the third decision step inspects electrical continuity between the press-fit terminals of the layered isolators. 
     Preferably, the first decision step inspects electrical continuity between the press-fit terminals constituting the first sub-harness. 
     Preferably, the second decision step inspects electrical continuity between the terminals constituting the second sub-harness. 
     Further preferably, the first press-fit terminal has a press-fit portion for press-fitting the first electrical cable on the terminal and a crimping piece for crimping the first electrical cable to the terminal, and a press-fitting machine press-fits the first electrical cable to the press-fit portion of the first press-fit terminal and the press-fitting machine crimps the first electrical cable to the crimping piece. The press-fitting machine has a plurality of press-fitting means with an electrical conductivity. The first decision step inspects electrical continuity between the press fit means each of which contacting the crimping piece when the first electrical cable is press-fitted to the first press-fit terminal. 
     According to the main aspect of the invention, the first decision step determines acceptance or rejection of the first sub-harness, and the second decision step determines acceptance or rejection of the second sub-harness. Thus, the sub-harnesses are checked one after another just after the assembling thereof, eliminating the production of a plurality of sub-harnesses having the same incorrectness of a short circuit or an open circuit. 
     The first or second decision step determines acceptance or rejection of the first or second sub-harness. Such incorrectness can be quickly found to be repaired, improving a productivity of the wiring harness. 
     Moreover, the sub-wiring harnesses are checked one after another so that the production of a type of sub-wiring harnesses, in which an incorrectness have been found, is stopped. This prevents an otherwise decreased productivity of the wiring harness. 
     According to one of the preferable aspects of the present invention, after completion of the wiring harness, it is only required that the predetermined press-fit terminals are checked in electrical continuity therebetween. This decreases a total checking time of the wiring harness. 
     The electrical continuity condition between the press-fit terminals mounted on the different isolators is checked, allowing a decreased check time of the wiring harness. Thus, in addition, the wiring harness can be checked when it is in the production line for combining the sub-harnesses. Accordingly, the wiring harness requires no transfer from the wiring harness assembling line to another specified check apparatus, allowing an improved productivity of the wiring harness. 
     According to another of the preferable aspects of the invention, during an assembling step of the first sub-harness for fitting the first electrical cable to the first press-fit terminal, the electrical continuity between the press-fit means contacting the press-fit terminals is checked. This enables to surely find an incorrect closed or open circuit of the first sub-harness. 
     The electrical continuity between the press-fit terminals constituting the first sub-harness is checked, allowing to surely find incorrectness of a short circuit or an open circuit of sub-harness. Such incorrectness can be quickly found, improving a productivity of the wiring harness. Furthermore, the electrical continuity check of the first electrical cable is carried out during a fitting work of the first press-fit terminal, allowing a further improved workability. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a flow chart showing a checking method of a wiring harness embodying the present invention; 
     FIG. 2 is a perspective view showing a sub-harness assembling line including production apparatuses for a sub-harness of the wiring harness, which is related to the checking method, and the sub-harness has a press-fit terminal at each end thereof; 
     FIG. 3 is a perspective view showing a sub-harness assembling line including production apparatuses for a sub-harness of the wiring harness, and the sub-harness has a press-fit terminal at one end and a crimp terminal at the other end thereof; 
     FIG. 4 is a plan view showing a wiring board used in a wiring harness assembling line for producing the wiring harness; 
     FIG. 5 is a schematic view showing a configuration of a first sub-check station of the sub-harness assembling line illustrated in FIG. 2; 
     FIG. 6 is a schematic view showing a configuration of a second sub-check station of the sub-harness assembling line illustrated in FIG. 3; 
     FIG. 7 is a schematic view showing a configuration of a wiring harness check station of a wiring harness assembling line; 
     FIG. 8 is a view illustrating a concept of a wiring harness assembled by a wiring harness production apparatus according to the present invention; 
     FIG. 9 is a perspective view of a press-fit terminal used in a joint connector of the wiring harness of the embodiment; 
     FIG. 10 is a perspective view showing some of the press-fit terminals of FIG. 9, the terminals being layered to electrically connect to each other; 
     FIG. 11 is a perspective view showing some of the press-fit terminals of FIG. 2, the terminals being disposed in parallel to electrically connect to each other; 
     FIG. 12 is a perspective view showing a terminal fitting housing of the wiring harness of FIG. 8; 
     FIG. 13 is a perspective view showing the terminal fitting housing of FIG.  12  and press-fit terminals used in a joint connector, which are just going to be inserted into the housing; 
     FIG. 14 is a perspective view showing the terminal fitting housings of FIG. 13 layered with a space therebetween; 
     FIG. 15 is a perspective view showing a connector defined by securing the terminal fitting housings of FIG. 13 to one another; 
     FIG. 16 is a perspective view showing a press-fit terminal used in a junction-box of a wiring harness of FIG. 8; 
     FIG. 17 is a perspective view showing a joint bar of the wiring harness of FIG. 8; 
     FIG. 18 is a perspective view showing a terminal fitting plate of the wiring harness embodying the present invention and showing in-junction-box disposed press-fit terminals and electrical cables received in the terminal fitting plate; 
     FIG. 19 is a perspective view showing the terminal fitting plates of FIG. 8 which are layered with a space therebetween; 
     FIG. 20 is a perspective view showing a distribution block defined by securing the terminal fitting plates of FIG. 8 to one another; 
     FIG. 21 is a perspective view showing an example of a sub-harness of the wiring harness shown in FIG. 8, and the sub-harness has press-fit terminals at each end thereof; 
     FIG. 22 is a perspective view showing another example of a sub-harness of the wiring harness shown in FIG. 8, and the sub-harness has press-fit terminals at each end thereof; 
     FIG. 23 is a perspective view showing further another example of a sub-harness of the wiring harness shown in FIG. 8, and the sub-harness has press-fit terminals at each end thereof; 
     FIG. 24 is a perspective view showing an example of a sub-harness of the wiring harness shown in FIG. 8, and the sub-harness has press-fit terminals at one end and crimp terminals at the other end; 
     FIG. 25 is a perspective view showing another example of a sub-harness of the wiring harness shown in FIG. 8, and the sub-harness has press-fit terminals at one end and crimp terminals at the other end; and 
     FIG. 26 is a schematic view showing a partial configuration of a random terminal press-fit machine used for assembling the sub-harnesses illustrated in FIGS. 21 to  23 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to FIGS. 8 to  25 , a wiring harness  1  of which acceptance or rejection is determined according to a checking method of an embodiment will be discussed hereinafter. 
     The wiring harness  1  illustrated in FIG. 8 is arranged in a motor vehicle to supply a power from a power source like a battery to on-vehicle electric appliances such as various lamps and various motors. 
     As illustrated in FIG  8 , the wiring harness  1  has a lot of electrical cables  4 , connectors  5  an electrical distribution block  6 , a connector  8 , and other fittings like a protector  7 . Each electrical cable  4  is an insulated one having a conductive wire core and an insulating sheath that covers the core. A plurality of the protectors  7  are provided at appropriate positions to adequately secure the electrical cables  4 . 
     The wiring harness  1  has at least one type of sub-harnesses freely selected from sub-harnesses  10   a ,  10   b , and  10   c  each having a press-fit terminal at each end as illustrated in FIGS. 21 to  23 . The wiring harnesses may have more than one of the sub-harnesses  10   a ,  10   b , and  10   c . That is, the wiring harness  1  may have any of the sub-harnesses  10   a ,  10   b , and  10   c.    
     Alternatively, the wiring harness  1  may have one or more of sub-harnesses  20   a  and  20   b  each having a press-fit terminal at one end and a crimp terminal at the other end as illustrated in FIGS. 24 and 25. Alternatively, the wiring harness  1  may have one or more of the sub-harnesses  10   a ,  10   b , and  10   c  and one or more of the sub-harnesses  20   a  and  20   b.    
     The wiring harness  1  is generally completed by incorporating the sub-harnesses  10   a ,  10   b , and  10   c  with the sub-harnesses  20   a  and  20   b  as described later. Note that the sub-harness  10   a ,  10   b , or  10   c  corresponds to the first sub-harness described in the summary of the invention, and the sub-harness  20   a  or  20   b  corresponds to the second sub-harness. 
     The sub-harness  10   a  illustrated in FIG. 21 has a parallel row of electrical cables  4   a , press-fit terminals  30   a  for a junction box, and terminal fitting housings  40   a . The press-fit terminal  30   a  is illustrated in FIGS. 9 to  11 , and the terminal fitting housing  40   a  that is an isolator is illustrated in FIGS. 12 to  15 . 
     Alternatively, the wiring harness  1  may have one or more of the sub-harnesses  20   a  and  20   b  each having a press-fit terminal at one end and a crimp terminal at the other end as illustrated in FIGS. 19 and 20. Alternatively, the wiring harness  1  may have one or more of the sub-harnesses  10   a ,  10   b , and  10   c  and one or more of the sub-harnesses  20   a  and  20   b.    
     The wiring harness  1  is generally completed by incorporating the sub-harnesses  10   a ,  10   b , and  10   c  with the sub-harnesses  20   a  and  20   b  as described later. Note that the sub-harness  10   a ,  10   b , or  10   c  corresponds to the first sub-harness described in the summary of the invention, and the sub-harness  20   a  or  20   b  corresponds to the second sub-harness. 
     The sub-harness  10   a  illustrated in FIG. 16 has a parallel row of electrical cables  4   a , press-fit terminals  30   a  for a junction box, and terminal fitting housings  40   a . The press-fit terminal  30   a  is illustrated in FIGS. 2 to  4 , and the terminal fitting housing  40   a  that is an isolator is illustrated in FIGS. 5 to  10 . 
     The press-fit terminal  30   a  is fitted to each end of the electrical cable  4   a . The press-fit terminal  30   a  is received in a terminal accommodation chamber  41 , which will be discussed later, of the terminal fitting housing  40   a.    
     The sub-harness  10   b  illustrated in FIG. 22 has a parallel row of electrical cables  4   a , press-fit terminals  30   a  for a joint connector, a press-fit terminal housing  40   a , press-fit terminals  50   a  for a junction box, and terminal fitting plates  60   a.  The press-fit terminal  30   a  is also illustrated in FIG. 16, and the terminal fitting plate  60  is also illustrated in FIGS. 18 to  20 . 
     The in-junction-box press-fit terminals  30   a  each are fitted to an end of the electrical cables  4   a . Each press-fit terminal  30   a  is received in the terminal accommodation chamber  41  of the terminal fitting housing  40   a . The in-junction-box press-fit terminal  50   a  is fitted to the other end of the electrical cables  4   a . The press-fit terminals  50   a  each are received in an electrical cable accommodation chamber  61 , which will be discussed later, of the terminal fitting plate  60   a.    
     The sub-harness  10   c  illustrated in FIG. 23 has a parallel row of electrical cables  4   a , press-fit terminals  50   a  for a junction box, and terminal fitting plates  60   a . The press-fit terminal  50   a  is fitted to each end of the electrical cables  4   a . The press-fit terminal  50   a  is received in an electrical cable accommodation chamber  61  of the terminal fitting plate  60   a.    
     In the examples illustrated in FIGS. 21 to  23 , the electrical cables  4   a  each are fitted to the terminal fitting housing  40   a  or to the terminal fitting plate  60   a  at each end thereof. However, the sub-harness  10   a ,  10   b , or  10   c  may have a plurality of the terminal fitting housings  40   a  or the terminal fitting plates  60   a  at each end side of the electrical cables  4   a.    
     The electrical cable  4   a  of the sub-harnesses  10   a ,  10   b , and  10   c  corresponds to the first electrical cable described in the summary of the invention. The press-fit terminal  30   a  and the press-fit terminal  50   a  of the sub-harnesses  10   a ,  10   b , and  10   c  correspond to the first press-fit terminals described in the invention summary. The terminal fitting housing  40   a  and the terminal fitting plate  60   a  of the sub-harnesses  10   a,    10   b,  and  10   c  correspond to the first isolators described in the invention summary. 
     The sub-harness  20   a  illustrated in FIG. 24 has a parallel row of electrical cables  4   b , press-fit terminals  30   b  for a junction box, terminal fitting housings  40   b , crimp terminals  90 , and connector housings  100 . The terminal fitting housing  40   b  functions as an isolator. 
     Each press-fit terminal  30   b  is fitted to an end of each electrical cable  4   b . The press-fit terminal  30   b  is received in a terminal accommodation chamber  41  of the terminal fitting housing  40   b . The crimp terminal  90  is defined by bending a conductor plate. The crimp terminal  90  is crimped to the other end of the electrical cable  4   b.    
     The connector housing  100  is made of an insulating synthetic resin material and has a box shape. The connector housing  100  has a plurality of terminal accommodation chambers  101  receiving the crimp terminals  90 . The terminal accommodation chamber  101  of the connector housing  100  receives the crimp terminal  90  crimped to the other end of the electrical cable  4   b . The connector housing  100  and the crimp terminals  90  received in the terminal accommodation chambers  101  constitute the connector  8 . 
     The sub-harness  20   b  illustrated in FIG. 25 has a parallel row of electrical cables  4   b , press-fit terminals  50   b  for a junction box, a terminal fitting plate  60   b  that functions as an isolator, crimp terminals  90 , and a connector housing  100 . 
     Each press-fit terminal  50   b  is fitted to an end of each electrical cable  4   b . The press-fit terminal  50   b  is received in an electrical cable accommodation chamber  61  of the terminal fitting plate  60   b . The crimp terminal  90  and the connector housing  100 , which are illustrated in FIG. 20, are the same as those of the sub-harness  20   a . Thus, the same reference numerals are provided for them not to be discussed again. 
     In the examples illustrated in FIG.  24  and FIG. 25, the electrical cables  4   b  are fitted to the terminal fitting housing  40   a  or the terminal fitting plate  60   a  at one end side thereof, while the electrical cables  4   b  are fitted to two separate connectors  8  at the other end side thereof. 
     Alternatively, the sub-harness  20   a  or  20   b  of the wiring harness  1  may have one or more than three connectors  8  at the other end side of the electrical cables  4   b.    
     The electrical cable  4   b  of the sub-harnesses  20   a  and  20   b  corresponds to the second electrical cable described in the invention summary. The press-fit terminal  30   b  and the press-fit terminal  50   b  for a junction-box of the sub-harness  20   a  and  20   b  correspond to the second press-fit terminals described in the invention summary. The terminal fitting housing  40   b  and the terminal fitting plate  60   b  of the sub-harness  20   a  and  20   b  each correspond to the second isolator described in the invention summary. 
     Since press-fit terminals  30   a  and  30   b  have the same configuration as each other, only the press-fit terminal  30   a  will be representatively discussed. The press-fit terminal  30   a  is defined by bending a conductor plate. As illustrated in FIGS. 2 and 3, the press-fit terminal  30   a  has a flat bottom wall  35  on which an electrical cable  4   a  is disposed, an electrical cable connection portion  31 , and an electrical contact piece  32 . 
     The electrical cable connection portion  31  has a pair of opposing crimping pieces  33  and three pairs of press fitting blades  34   a ,  34   b , and  34   c . The crimping pieces  33  and the press fitting blades  34   a ,  34   b , and  34   c  are vertically extending relative to the bottom wall  35 . 
     The crimping pieces  33  are bent to hold the electrical cable  4   a  disposed on the bottom wall  35 . The press fitting blades  34   a ,  34   b , and  34   c  receive the electrical cable  4   a  which is inserted between each pair of the blades. Thereby, the blades cut into the sheath of the electrical cable  4   a  to contact the wire core to electrically connect to the electrical cable  4   a . That is, the press-fitting of the blades for the electrical cable  4   a  is completed. 
     The electrical contact piece  32  has an opening  36  (see FIG. 10) provided in the bottom wall  35  and has a contact piece  37  raised from the bottom wall  35  and serving as a connection means. The contact piece  37  is changeable from a rising position to a parallel position relative to the bottom wall  35  by a bending work. The parallel position is illustrated by a chain line in FIG.  9 . 
     Note that the contact piece  37  permanently maintains the rising position or the parallel position once the position is determined. As illustrated in FIG. 3, the opening  36  has a resilient contact piece  38  for press-fitting the contact piece  30  to an end of the bottom wall  35 . 
     The press-fit terminals  30   a  for a joint connector are layered with a space therebetween in parallel to the bottom wall  35 . The electrical contact piece  32  electrically connects the press-fit terminals  30   a  to one another, since the contact piece  37  of the press-fit terminal  30   a  is inserted into the opening  36  of another upper press-fit terminal  30   a  as illustrated in FIG.  10 . 
     At the same time, the contact piece  37  of the lower press-fit terminal  30   a  is pinched between an end part of the bottom wall  35  and the resilient contact piece  38  of the upper press-fit terminal  30   a.    
     As illustrated in FIG. 6, the press-fit terminal  30   a  is forced into a terminal accommodation chamber  41  of a terminal fitting housing  40   a . Thereby, the press-fit terminal  30   a  is received in the terminal fitting housing  40   a  to be secured therein. 
     When received in the terminal accommodation chambers  41 , the press-fit terminals  30   a  are disposed in parallel to one another. Adjacent two of the press-fit terminals  30   a  each have a connection piece  39  to electrically connect each other as illustrated in FIG.  11 . The connection piece  39  is provided in the side of the electrical cable connection portion  31  of the bottom wall  35 . 
     Since the terminal fitting housings  40   a  and  40   b  have the same configuration as each other, only the terminal fitting housing  40   a  will be representatively discussed. The terminal fitting housing  40   a  is made of an insulating synthetic resin material or the like. As illustrated in FIGS. 12 to  15 , the terminal fitting housing  40   a  has a rectangular plate-like main body  42 , a plurality of partitions  43  rising from the main body  42 , and a plurality of terminal accommodation chambers  41 . The partitions  43  are parallel to one another and define the terminal accommodation chambers  41  between them. 
     A plurality of the terminal fitting housings  40   a , each of which has received the press-fit terminals  30   a  in the terminal accommodation chambers  41 , are layered with the main bodies being parallel to one another to define the connector  5  as illustrated in FIG.  15 . At that time, the electrical cable  4   a  is fitted to each press-fit terminal  30   a  secured in the housing  40   a . Then, as illustrated in FIG. 14, the terminal fitting housings  40   a  each of which has received the electrical cable  4   a  are layered. 
     Each terminal fitting housing  40   a  has a plurality of lock projections  44  and locking recesses  45  for securing them to one another when layered as illustrated in FIGS. 12 and 13. Furthermore, the terminal fitting housing  40   a  has a plurality of openings (not shown) each receiving the contact piece  37  of a lower one of press-fit terminals  30   a  so that the contact piece  37  can pass through the opening  36  of an upper one of press-fit terminals  30   a.    
     Since the press-fit terminals  50   a  and  50   b  for a junction box have the same configuration as each other, only the press-fit terminal  50   a  will be representatively discussed hereinafter. The press-fit terminal  50   a  is formed from a conductor plate by a bending work. As illustrated in FIG. 16, the press-fit terminal  50   a  has a flat bottom wall  55  on which the electrical cable  4   a  is disposed, an electrical cable connection portion  51 , and an electrical contact piece  52 . 
     The electrical contact piece  51  is received in an electrical cable accommodation chamber  61 . The electrical cable connection portion  51  has two pairs of opposing crimping pieces  53   a , and  53   b  and three pairs of opposing press fitting blades  54   a ,  54   b , and  54   c . The crimping pieces  53   a , and  53   b  and the press fitting blades  54   a ,  54   b , and  54   c  are vertically extending relative to the bottom wall  55 . 
     The crimping pieces  53   a , and  53   b  are bent to hold the electrical cable  4   a  disposed on the bottom wall  35 . The press fitting blades  54   a ,  54   b , and  54   c  receive the electrical cable  4   a  which is received between each pair of the blades. Thereby, the blades cut into the sheath of the electrical cable  4   a  to contact the wire core to electrically connect to the electrical cable  4   a . That is, the press-fitting of the blades for the electrical cable  4   a  is completed. 
     The electrical contact piece  52  has a contact bar  56  along a side edge of the bottom wall  55 . The contact bar  56  is a rectangular hollow piece. The electrical contact piece  52  is disposed such that the hollow of the contact bar  56  communicates with a through hole described later of the terminal fitting plate  60   a . Through the hollow of the contact bar  56 , there is inserted a joint bar  80  illustrated in FIG. 17 for electrical connection thereof. The contact bar  56  has a pair of resilient contact pieces  57  for press-contacting the joint bar  80  thereto. 
     The joint bar  80  is inserted into the hollows of the contact bars  56  after the terminal fitting plates  60   a  have been layered. Thus, the electrical contact pieces  52  allow electrical connection of the terminals between the terminal fitting plates  60   a  to one another. 
     A press-fit terminal  50   a  used in a junction-box is forced into one of the electrical cable accommodation chambers  61  of the terminal fitting plate  60   a . Thereby, The press-fit terminal  50   a  is held by the terminal fitting plate  60   a . The joint bar  80  is substantially a flat bar made of a conductor metal or the like. 
     The terminal fitting plates  60   a  and  60   b  have the same configuration as each other. Thus, only the terminal fitting plate  60   a  will be representatively discussed hereinafter. The terminal fitting plate  60   a  is made of an insulating synthetic resin material or the like. As illustrated in FIGS. 18 to  20 , the terminal fitting plate  60   a  has a rectangular plate-like main body  62 , a plurality of partitions  63  rising from the main body  62 , a plurality of electrical cable accommodation chambers  61 , a plurality of receiving recesses  64 , and through openings (not shown). 
     The partitions  63  are arranged in parallel to one another with a space therebetween. The space between two adjacent partitions  63  defines the electrical cable accommodation chamber  61 . The recess  64  receives the contact bar  56  of the press-fit terminals  50   a  used in the junction-box. 
     The receiving recess  64  is defined to provide a wider distance between the two adjacent partitions  63 . There are provided a plurality of the receiving recesses  64  along a longitudinal direction of the electrical cable accommodation chambers  61 . The through hole is provided for each receiving recess  64 . The hole passes through the main body  62 . 
     As illustrated in FIGS. 18 and 19, the terminal fitting plate  60   a  receives the press-fit terminals  50   a  in the electrical cable accommodation chambers  61  and the receiving recesses  64 . Then, the plate-like main bodies  62  are layered in parallel. The joint bars  80  are inserted into the associated through holes and the hollows of the contact bars  56 , so that the terminal fitting plates  60   a  define an electrical distribution block  6  as illustrated in FIG.  20 . 
     At the same time, the press-fit terminals  50   a  each are connected to the electrical cable  4   a . The terminal fitting plate  60   a  has a plurality of lock projections (not shown) and locking holes  66  engageable with the lock projections. The engagement of the lock projections with the locking holes  66  secures the terminal fitting plates  60   a  to each other. 
     The wiring harness  1  is completed by layering the terminal fitting housings  40   a  or  40   b  or the terminal fitting plates  60   a  or  60   b , which are consisting of the sub-harnesses  10   a ,  10   b ,  10   c ,  20   a , or  20   b , to secure them to each other according to a predetermined pattern. 
     In the terminal fitting housings  40   a  and  40   b  which have been layered to be secured to each other, the contact pieces  37  electrically connect the in-joint-connect or disposed press-fit terminals  30   a  and  30   b  held by different terminal fitting housings  40   a  and  40   b.    
     In the terminal fitting plates  60   a  and  60   b  which have been layered to be secured to each other, the joint bars  80  electrically connect the in-junction-box disposed press-fit terminals  50   a  and  50   b  held by different terminal fitting plates  60   a  and  60   b  to each other. The mutual connection of the different press-fit terminals  50   a  and  50   b  results in mutual electrical connection of the electrical cables  4   a  and  4   b  fitted with the different terminals  50   a  and  50   b.    
     That is, in the wiring harness  1 , a connection portion for electrically connecting the electrical cables  4   a  and  4   b  to each other is defined by the layering of the terminal fitting housings  40   a  and  40   b  or the terminal fitting plates  60   a  and  60   b  and by the connection of the terminals  30   a ,  30   b ,  50   a , and  50   b  through the joint bars  80 . 
     Next, referring to FIGS. 1 to  7 , a production apparatus and a method thereof of the wiring harness  1  will be discussed. The wiring harness production apparatus has a first sub-harness assembling line illustrated in FIG. 2 and a second sub-harness assembling line illustrated in FIG.  3 . The first sub-harness assembling line is an assembling line  201  for press-fitting a terminal to each end of an electrical cable. The second sub-harness assembling line is an assembling line  202  for press-fitting a terminal to one end of an electrical cable and for crimping another terminal to the other end of the electrical cable. 
     The sub-harness assembling line  201  assembles the sub-harness  10   a ,  10   b , or  10   c  each having the press-fit terminals at each end thereof. A plurality of the sub-harness assembling lines  201  are provided, and the number of the assembling lines  201  is the same as the different type number of the sub-harnesses  10   a ,  10   b , and  10   c  used for the wiring harness  1 . That is, each sub-harness assembling line  201  assembles one type of the sub-harnesses  10   a ,  10   b , and  10   c.    
     As illustrated in FIG. 2, the sub-harness assembling line  201  has a press-fit terminal inserting station  210 , a predetermined-length electrical cable preparing station  211 , a press-fitting station  212 , and a first sub-check station  213 . 
     The press-fit terminal inserting station  210  forces the press-fit terminals  30   a  or  50   a  into the terminal accommodation channels  41  and the electrical cable receiving channels  61  of the housing  40   a  or into the plate  60   a  to obtain the sub-harness  10   a ,  10   b , or  10   c.    
     The cable preparing station  211  cuts an electrical cable supplied from an electrical cable supply station (not shown) into cables having a predetermined length. The predetermined-length electrical cables are held by a known retainer bar. The electrical cable supply station has a plurality of reels each for winding one of different types of the electrical cables. 
     The retainer bar has a plurality of clips for holding the electrical cables. The electrical cable clips align with one another in a direction. Each electrical cable clip has a pair of pieces for pinching the electrical cable  4   a  therebetween. 
     The press-fitting station  212  press-fits each end of the electrical cable  4   a  to the press-fit terminal  30   a  or  50   a  received in the housing  40   a . or the plate  60   a  according to a predetermined pattern. 
     The first sub-check station  213  provides an electrical continuity check for the sub-harnesses  10   a ,  10   b , and  10   c  which have been obtained through the cable preparing station  211  and the press-fitting station  212 . As illustrated in FIG. 5, the first sub-check station  213  has an interface connector  240 , an input/output switching circuit  241 , a control unit  242 , etc. 
     The interface connector  240  can couple to connectors provided in the housing  40   a  and the plate  60   a . The interface connector  240  has a plurality of connection terminals. The connection terminals connect to the press-fit terminals  30   a  and  50   a , when the interface connector  240  engages with the connectors of the housing  40   a  and the plate  60   a . The connection terminals of the interface connector  240  connect to the input/output switching circuit  241 . 
     The input/output switching circuit  241  applies a voltage to each connection terminal based on a data sequentially provided from a CPU (not shown) of the control unit  242 . The input/output switching circuit  241  determines whether the voltage of each connection terminal is higher or lower than a reference voltage. The decisions are sequentially stored in the control unit  242 . 
     The control unit  242  is a calculation unit having a known CPU. The control unit  242  communicates with the input/output switching circuit  241  and the interface connector  240  to control them, which controls the whole first sub-check station  213 . 
     The first sub-check station  213  applies a voltage to one of the press-fit terminals  30   a  and  50   a  and determines whether each of the other terminals has a voltage higher or lower than the reference voltage. To each press-fit terminals  30   a  and  50   a , a voltage is sequentially applied to obtain electrical continuity relationships among the press-fit terminals  30   a  and  50 . The first sub-check station  213  determines acceptance or rejection of each sub-harness  10   a ,  10   b , or  10   c  based on the comparison of an obtained electrical continuity condition with a normal one. 
     The sub-harness assembling line  202  assembles the sub-harnesses  20   a  and  20   b  each having a press-fit terminal at one end and a crimp terminal at the other end. The number of the sub-harness assembling lines  202  is the same as the number of different types of the sub-harnesses  20   a  and  20   b  used in wiring harness  1 . That is, one of the sub-harness assembling lines  202  corresponds to one type of the sub-harnesses  20   a  and  20   b.    
     As illustrated in FIG. 3, the sub-harness assembling line  202  has a press-fit terminal inserting station  220 , a predetermined-length electrical cable preparing station  221 , a press-crimping station  222 , a press-fitting station  223 , a terminal inserting station  224 , and a second sub-check station  227  (see FIG.  6 ). 
     The press-fit terminal inserting station  220  press-fits the press-fit terminals  30   b  or  50   b  to the terminal accommodation channels  41  and the electrical cable receiving channels  61  of the housing  40   b  or to the plate  60   b  used in the sub-harnesses  20   a  and  20   b.    
     The cable preparing station  221  cuts an electrical cable supplied from an electrical cable supply station (not shown) to obtain a predetermined-length one. The obtained cables are held by the retainer bar. The cable preparing station  221  has a machine  225  for stripping one end of the electrical cable  4   b  held by the retainer bar. 
     The electrical cable supply station has a plurality of reels each for winding a different type of electrical cables. Note that a retainer bar used in the sub-harness assembling line  202  has the same configuration as that of the sub-harness assembling line  201 . Thus, the retainer bar will not be discussed again. 
     The press-crimping station  222  has a plurality of crimping machines  226 . The crimping machine  226  has a fixed lower molding die and an upper molding die movable relative to the lower die. The crimping machine  226  holds the stripped end of the electrical cable  4   b  and the crimp terminal  90  between the upper and lower molding dies to crimp the electrical cable  4   b  and the crimp terminal  90 . 
     The crimping machines  226  align with one another in a direction in which there are disposed the cable preparing station  221 , the press-crimping station  222 , and the press-fitting station  223 , and the terminal inserting station  224 . The aligned crimping machines  226  are different from one another in the upper and lower molding dies and in the distance therebetween according the types of the electrical cable  4   b  and the crimp terminal  90 . The press-crimping station  222  crimps the crimp terminal  90  to one end of the electrical cable  4   b  held by the retainer bar. 
     The press-fitting station  223  press-fits one of the press-fit terminals  30   b  and  50   b , which is received in the housing  40   b  or the plate  60   b , to the other end of the electrical cable  4   b  according to a predetermined pattern. 
     The terminal inserting station  224  inserts the crimp terminal  90  crimped to the electrical cable  4   b  into the terminal accommodation chamber  101  of the connector housing  100 . Thereby, the terminal inserting station  224  fits the connector housing  100  to the other end of the electrical cable  4   b.    
     The second sub-check station  227  makes an electrical continuity check for each sub-harness  20   a  or  20   b  obtained through the cable preparing station  221 , the press-crimping station  222 , the press-fitting station  223 , and the terminal inserting station  224 . 
     As illustrated in FIG. 6, the second sub-check station  227  has the same configuration as the first sub-check station  213 . Thus, the second sub-check station  227  is provided with the same reference numerals as those of the first sub-check station  213  and will not be discussed again. The second sub-check station  227  determines acceptance or rejection of each terminal  30   b ,  50   b , or  90  by checking electrical continuity relationships with the other terminals  30   b ,  50   b , or  90 . 
     In the embodiment, the sub-harness assembling line  202  has an electrical cable rearranging station  228  as illustrated in FIG.  3 . The electrical cable rearranging station  228  is disposed between the press-crimping station  222  and the press-fitting station  223 . 
     The rearranging station  228  rearranges the electrical cables  4   b  held by the retainer bar so that the stations  223 ,  224  may carry out smooth press-fit and insertion steps. 
     The wiring harness assembling line has a plurality of wiring boards  230  (see FIG.  4 ), a press-fit connector assembling tool, a press-fit-type distribution block assembling tool, and a wiring harness check station  233  (see FIG.  7 ). 
     The wiring board  30  is a plate movable along a rail on a floor of a factory. The wiring board  230  may be mounted on an automatically running bogie traveling along a predetermined way. On the wiring board  230 , there is pictured a wiring arrangement pattern for arranging the electrical cables  4 , the connectors  8 , and other additional fittings including the protectors  7 . The wiring board  120  has a plurality of clips  235  supporting the sub-harnesses  10   a ,  10   b ,  10   c ,  20   a , or  20   b  according to the wiring arrangement pattern to assemble the wiring harness  1 . 
     As illustrated in FIG. 4, the wiring board  230  also has a plurality of press-fit housing supports  236  and press-fit plate supports  237 . The clip  235  bundles together some of the sub-harnesses  10   a ,  10   b ,  10   c ,  20   a , and  20   b.    
     The housing support  236  supports the housings  40   a  and  40   b  of the sub-harnesses  10   a,    10   b,  and  20   a , while the main plate bodies  42  are spaced from each other. 
     The housing support  237  supports the housings  60   a  and  60   b  of the sub-harnesses  10   b ,  10   c , and  20   b , while the main plate bodies  62  are spaced from each other. 
     The connector assembling tool is disposed near the traveling course of the wiring board  230 . The connector assembling tool press-fits the housings  40   a  and  40   b  held by the housing support  236  to one another so that the lock projections  44  engage with the locking recesses  45 . The connector assembling tool assembles the connectors  5 . 
     The distribution block assembling tool is disposed near the traveling course of the wiring board  230 . The distribution unit assembling tool press-fits the plates  60   a  and  60   b  held by the plate support  237  to each other so that the lock projection may engage with and lock in the locking hole  66 . The distribution unit assembling tool inserts the joint bars  80  into the predetermined through holes to contact with the contact bars  56  of the press-fit terminals  50   a  and  50   b  for assembling the distribution line unit  6 . 
     The wiring harness check station  233  is disposed near the traveling course of the wiring board  230  at a final end of the assembling line of the wiring harness  1 . The wiring harness check station  233  checks electrical continuity of the wiring harness  1  held by the wiring board  230 . 
     As illustrated in FIG. 7, the wiring harness check station  233  has a plurality of interface connectors  260 , an input/output switching circuit  261 , a control unit  262 , etc. The interface connector  260  can engage with the connector  5 , the distribution block  6 , or the connector  8 . 
     The interface connector  260  has a plurality of connection terminals (not shown). The connection terminals contact the terminals  30   a ,  30   b ,  50   a ,  50   b , and  90 , when the interface connector  260  engages with the connector  5 , the distribution block  6 , and the connector  8 . The connection terminals of the interface connector  260  connect to the input/output switching circuit  261 . 
     The input/output switching circuit  261  applies a voltage to a sequentially selected one of the connection terminals of the interface connectors  260  which have engaged with the connector  5 , the distribution line unit  6 , or the connector  8 . The input/output switching circuit  261  determines whether each connection terminal related to the selected one has a voltage higher or lower than a reference voltage, and the decisions are sequentially stored in the control unit  262 . 
     The control unit  262  is a calculation unit having a known CPU. The control unit  262  communicates with the input/output switching circuit  261  and the interface connectors  260  to control them, which controls the whole wiring harness check station  233 . 
     The wiring harness check station  233  applies a voltage to a selected one of the press-fit terminals  30   a  and  30   b  of the connector  5  and determines whether each of the other terminals has a voltage higher or lower than a reference voltage. To each press-fit terminals  30   a  and  30   b , a voltage is sequentially applied to obtain electrical continuity relationships of the press-fit terminals  30   a  and  30   b . The wiring harness check station  233  determines acceptance or rejection of the connector  5  based on the comparison of an obtained electrical continuity condition with a normal one. 
     The wiring harness check station  233  also applies a voltage to a selected one of the press-fit terminals  50   a  and  50   b  of the distribution line unit  6  and determines whether each of the other terminals has a voltage higher or lower than a reference voltage. To each press-fit terminal  50   a  and  50   b , a voltage is sequentially applied to obtain electrical continuity relationships of the press-fit terminals  50   a  and  50   b . The wiring harness check station  233  determines acceptance or rejection of the distribution line unit  6  based on the comparison of an obtained electrical continuity condition with a normal one. 
     Thus, the wiring harness check station  233  checks the electrical continuity relationships of the press-fit terminals  30   a  and  30   b  of the connector  5  and checks the electrical continuity relationships of the press-fit terminals  50   a  and  50   b  of the distribution block  6 . That is, the wiring harness check station  233  checks mutual electrical continuity conditions of the terminals  30   a ,  30   b ,  50   a , and  50   b  received in the layered housings  40   a  and  40   b  or in the layered plates  60   a  and  60   b.    
     The wiring harness check station  233  checks the electrical continuity among the layered housings  40   a  and  40   b  and among the plates  60   a  and  60   b . The wiring harness check station  233  checks the electrical continuity separately for the connector  5  and the distribution block  6 . 
     Referring to FIG. 1, manufacturing steps for the thus configured wiring harness  1  will be discussed hereinafter. 
     Step S 1   a  or S 1   b  assembles the sub-harness  10   a,    10   b ,  10   c ,  20   a , or  20   b  in the sub-harness assembling line  201  or  202 . 
     In a next step S 2   a , the first sub-check station  213  checks the electrical continuity of the sub-harnesses  10   a,    10   b , and  10   c . In another next step S 2   b , the second sub-check station  227  checks the electrical continuity of the sub-harnesses  20   a  and  20   b . When steps S 2   a , S 2   b  are normal, step S 3  will be carried out. Note that steps S 2   a  and S 2   b  correspond sequentially to the first and second decision steps described in the summary of the invention. 
     In the wiring harness assembling line, step S 3  layers the housings  40   a  and  40   b  or layers the plates  60   a  and  60   b  one after another to obtain the connector  5  or the distribution line unit  6 . The sub-harnesses  10   a,    10   b,    10   c ,  20   a , and  20   b  are thus combined. Furthermore, other fittings including the protectors  7  are furnished at predetermined points before step S 4  is carried out. 
     In step S 4 , the wiring harness check station  233  checks the electrical continuity condition among the press-fit terminals  30   a ,  30   b ,  50   a , and  50   b  for each of the connectors  5  and the distribution line units  6 . Note that step S 4  corresponds to the third decision step described in the summary of the invention. 
     Thus, step S 4  checks the electrical continuity conditions among the terminals  30   a  and  30   b  constituting the connector  5  and also checks the electrical continuity conditions among the terminals  50   a  and  50   b  constituting the distribution block  6 . When step S 4  is normal, step S 5  will be carried out. An appearance inspection of Step S 5  confirms the completion of the wiring harness  1 . 
     The sub-harnesses  10   a ,  10   b ,  10   c ,  20   a , and  20   b  of the embodiment have the electrical cables  4   a  and  4   b  each of which is fitted with the terminal  30   a ,  30   b ,  50   a ,  50   b , or  90  at each end thereof. 
     These terminals  30   a ,  30   b ,  50   a ,  50   b , and  90  each are received in one of the housing  40   a  or  40   b , the plate  60   a  or  60   b , and the connector housing  100 . The sub-harnesses  10   a,    10   b ,  10   c ,  20   a , and  20   b  each compose a partial circuit. Thus, an electrical continuity check can be carried out for each sub-harness  10   a ,  10   b ,  10   c ,  20   a , or  20   b.    
     According to the checking method related to the wiring harness production apparatus, the first sub-check station  213  checks the sub-harnesses  10   a ,  10   b , and  10   c  each having press-fit terminals, allowing to surely find incorrectness of a shirt circuit or an open circuit of the sub-harnesses  10   a ,  10   b,  and  10   c.    
     Furthermore, the second sub-check station  227  checks the sub-harnesses  20   a  and  20   b  each having a press-fit terminal and a crimp terminal, allowing to surely find incorrectness of a shirt circuit or an open circuit of the sub-harnesses  20   a  and  20   b . Such incorrectness can be quickly found to be repaired, improving a productivity of the wiring harness  1 . 
     Moreover, the sub-wiring harnesses  10   a ,  10   b ,  10   c ,  20   a , and  20   b  are checked one after another so that the production of a type of sub-wiring harnesses, in which an incorrectness have been found, is stopped. This prevents an otherwise decreased productivity of the wiring harness  1 . 
     The wiring harness assembling line checks the electrical continuity relationships among the terminals  30   a ,  30   b ,  50   a , and  50   b  of the connector  5  and the distribution block  6 , allowing a decreased check time of the wiring harness  1 . In addition, the wiring harness  1  can be checked when it is on the wiring board  230 . 
     Accordingly, the wiring harness  1  requires no transfer from the wiring harness assembling line to another specified check apparatus, allowing an improved productivity of the wiring harness  1 . 
     In the aforementioned embodiment, for assembling the sub-harnesses  10   a ,  10   b , and  10   c , there are provided the cable preparing station  211  and the press-fitting station  212 . However, the stations  211  and  212  may be replaced by a random terminal press-fit machine  300  disclosed in Japanese Patent Application Laid-open No. H. 7-296933, which is partially illustrated in FIG.  26 . Note that the random terminal press-fit machine  300  may be the press-fit machine described in the summary of the invention. 
     The random terminal press-fit machine  300  has a plurality of press-fit blades  301  and a check unit  302 . In FIG. 26, there are provided a pair of press-fit blades  301 . The press-fit blade  301  is made of an electrically conductive metal material. The press-fit blade  301  presses the electrical cable  4   a  or  4   b  into a space between a pair of the press-fit pieces  34   a ,  34   b ,  34   c ,  54   a ,  54   b , or  54   c  and bends the crimping pieces  33  or  53   b.    
     That is, the press-fit blade  301  press-fits the electrical cable  4   a  or  4   b  and bends the crimping pieces  33  or  53   b  to fit the electrical cable  4   a  or  4   b  to the press-fit terminal  30  or  50 . Note that the press-fit blade  301  contacts the crimping piece  33  or  53   b  during the crimping. The press-fit blade  301  corresponds to the press-fit means described in the summary of the invention. 
     The check unit  302  checks the electrical continuity between the press-fit blades  301 . During the use of the random terminal press-fit machine  300 , the electrical continuity between the press-fit blades  301  is checked while the electrical cable  4   a  or  4   b  is fitted with the press-fit terminals  30  or  50 . This can check the electrical continuity between the press-fit terminals  30  or  50 , that is, for the sub-harnesses  10   a ,  10   b , and  10   c.    
     In the present invention, the sub-harness assembling line  202  may assemble plural types of the sub-harnesses  10   a ,  10   b , and  10   c . The wiring board  230  may be mounted on an automatically running bogie traveling along a desirable way on a floor of a factory. 
     Note that the wiring harness  1  described above may have an electrical cable having a crimp terminal fitted at each end thereof.