Abstract:
A method of producing a battery-connecting plate by providing busbars which connect batteries together, attaching terminals to one end of wires to produce terminal-attached wires for detecting voltage of desired ones of the batteries, placing the terminal-attached wires in a predetermined layout in a wire protector, setting the busbars and wire protector in a mold with the burbars positioned corresponding to an arrangement of the batteries, injecting resin into the mold to produce a molded piece with the burbars and the terminal-attached wires therein, and cutting an element mount portion of each of the terminals and connecting a respective circuit protector element to the element mount portion in a bridging manner across the cut.

Description:
This application is a division of prior application Ser. No. 09/413,242 filled Oct. 7, 1999 now U.S. Pat. No. 6,346,011. 

   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   This invention relates to a battery-connecting plate for use with a battery holder which receives a large number of cylindrical batteries and which is mounted as in an electric vehicle, a method of producing same, and a wire protector. 
   2. Description of the Related Art 
   A battery-connecting plate  100  as shown in  FIGS. 18A ,  18 B is conventionally used as a means of connecting a plurality of batteries in series or in parallel. 
   The connecting plate  100  includes a molded resin plate  103 , a busbar  102  for connecting two batteries  101 , fixed in the resin plate  103  by molding, the two batteries having nut-type positive and negative electrodes  101   a ,  101   b , and a hexagonal and a square windows  103   a ,  103   b  in which electrode-connecting busbar holes  102   a  are exposed. The connection of the two batteries  101  is effected by fastening the busbar  102  to the nut-type positive and negative electrodes  101   a ,  101   b  with the bolts  104 , at which time at the hexagonal window  103   a  a round terminal  105 , which constitutes part of a voltage detecting circuit, is concurrently connected. In other words, the wire  106  connected to the round terminal  105  has a fuse  108  interposed in series therein and extends therefrom to a not-shown ECU. The fuse  108 , which is enclosed in a fuse casing  107 , is connected at its opposite ends, via a female terminal  109 , to the wire  106 . 
     FIG. 19  shows another example of a conventional connecting plate. 
   The connecting plate  100 ′ includes a molded resin plate  103  and a plurality of L-shaped busbars  102 ′ fixed in the resin plate  103  by molding, the L-shaped busbars having connection legs  102   b ′ of different lengths which have one end projected at one side of the molded resin plate  103 . A wire  106  is welded at one end to the thus projected end of each L-shaped busbar and extends, via a fuse  108 ′ enclosed in a fuse casing  107 ′, to a not-shown ECU. 
   The fuse casing  107 ′ includes a base plate  110  and a pair of opposed L-shaped pressure-welding terminals  111  provided on the base plate, the pair of terminals  111  each having a base plate  111   a  whereat the wire  106  is welded and a pressure-welding piece  111   b  with a slot  111   c  rising from the base plate  111   a , and the fuse  108  having its leads  108   a ′ pressure-welded via the slots  111   c  to the respective pressure-welding pieces  111   b.    
   The connecting plate  100  of  FIG. 18  requires many connections in one circuit, for example, six connections in the voltage detecting circuit as shown at characters a, b . . . f, and also requires a large components count, possibly resulting in reliability in electric connection lowered. Further, the wired round terminals  105  require a manual operation one by one during their bolting, and hence as the number of wires  106  increases, it will become troublesome to bolt the round terminals  105  and to lay their wires  106 . 
   On the other hand, the connecting plate  100 ′ of  FIG. 19  requires L-shaped busbars  102 ′ of different sizes, and hence is disadvantageous in the production cost of the L-shaped busbars and their administration. Further, as is the case of the connecting plate  100 , there are required a large components count and a large connections count in one circuit (five connections of a′, b′ . . . e′), and besides difficulty is encountered in protecting the welds between the wires  106  and their corresponding connection legs  102   b′.    
   Further, the connection wires  106  of the connecting plates  100 ,  100 ′, being directly connected to the related batteries  101 , need to be properly protected. Due to the bulky member of the fuse casing  107 ,  107 ′ interposed, however, such a protection structure will inevitably become complicated. 
     FIG. 20  shows the case in which batteries are connected together not with a connecting plate, but directly with wires. In other words, each prism-shaped battery  101 ′ has positive and negative electrodes  101   a ′,  101   b ′, juxtaposed at one end, a main power wire  112  is used to connect neighboring batteries to each other, and wires  106  each with a fuse casing  107  (voltage detecting circuits), as in the case of  FIG. 18 , are connected to predetermined electrodes  101   b′.    
   Also in this case, a large components count is required. Further, the wires are dangerously exposed at many portions. In addition, due to the intersecting main power wires  112  and voltage detecting circuit constituting wires  106 , the wiring becomes complicated so as to cause an improper wiring. 
   Under these conditions, it is conceived to embed the connection wires  106  of the connecting plate  100 ,  100 ′ in the molded resin plate  103  by insert molding. 
   With a conventional method of insert molding, however, as shown in  FIGS. 21A ,  21 B, the wires  113 , although firmly fixed inside the molded resin plate  114 , become free outside the plate. Consequently, concentration of stress tends to take place at the roots  113   a  of the wires  113  located at the edge of the molded resin plate  114 , so that in extreme cases the wires  113  are cut at the roots  113   a  by the action of a minimal external force. To prevent this, it is conceived to bundle the wires  113  with a band  115  or to fix the wires to a wall of the molded resin plate  114  through a fixture. The concentration of stress at the roots  113   a , however, cannot be fully precluded, because the above operation is effected only after completion of the insert molding. 
   Further, there remains another cause of the cutting of the wires  113  at the roots  113   a , which is the biting by the upper and lower dies  116  at the outlet of the wires. 
   Further, with a conventional method of insert molding, because, as shown in  FIG. 22 , the molten resin injected from the nozzle  119  of a molding machine into the mold  116  has a temperature higher than the heat-resisting temperature of the insulating cover  113   b  of commonly used wires  113 , it has been required to use heat-resistant wires covered as with polyimide, resulting in a cost increase. 
   SUMMARY OF THE INVENTION 
   This invention has been accomplished to overcome the above drawbacks and an object of this invention is to provide a battery-connecting plate which has integrally incorporated therein by insert molding battery-connecting busbars, voltage-detecting-circuit-constituting terminals and others, so that these components are less exposed to the outside, and is safe and easy to mount, and to provide a method of producing such battery-connecting plate. 
   Another object of this invention is to provide a battery-connecting plate which has a low parts count and low connections count, is highly reliable in electric connection, and does not cause improper connection and improper wiring to batteries. 
   Yet another object of this invention is to provide a battery-connecting plate which does not cause concentration of stress at that part of connection wires whereat the connection wires extend out of the molded resin plate. 
   Yet another object of this invention is to provide a method of producing a connecting plate according to which a commonly used wire covered with polyvinyl chloride or polyethylene can be used in place of a special heat-resistant wire such as polyimide-covered wire and which can thus be produced at a low cost. 
   A further object of this invention is to provide a wire protector which enables the production of the connecting plate as mentioned above. 
   In order to attain the objects, according to an aspect of this invention, there is provided a battery-connecting plate which comprises: busbars for connecting batteries together; and a wire protector which holds in a predetermined layout therein terminals and their connection wires for detecting voltage of desired ones of the batteries, the busbars and the wire protector being fixed in a resin plate by insert molding, with the busbars arranged in correspondence with the batteries and with the terminals held in contact with related ones of the busbars. 
   Preferably, the terminals each comprises a contact portion superimposed on the respective busbar, a wire connecting portion at which connected to the respective connection wire, and an element mount portion linking the contact portion and the wire connecting portion, and the connecting plate further comprises circuit protector elements which are, after completion of the insert molding, connected to the respective element mount portions of the terminals. 
   Preferably, the connection wires connected to the respective terminals are let out of the resin plate at one side thereof. 
   According to another aspect of this invention, there is provided a method of producing the battery-connecting plate as mentioned above, which comprises the steps of: providing busbars which connect batteries together; attaching terminals to one end of wires to produce terminal-attached wires for detecting voltage of desired ones of the batteries, the terminals each having a contact portion, a wire connecting portion at which attached to the respective wire, and an element mount portion linking the contact portion and the wire connecting portion; placing the terminal-attached wires in a predetermined layout in a wire protector, with tail portions of the wires let out at one side of the wire protector; setting the busbars and the wire protector in a mold such that the busbars are in position corresponding to an arrangement of the batteries, and the terminals have their contact portions superimposed on the respective busbars; injecting resin into the mold to produce a molded piece with the busbars and the terminal-attached wires embedded threin, with the contact portions of the terminals on the respective busbars and the element mount portions of the terminals left uncovered by the resin; and cutting the element mount portion of each of the terminals and connecting a respective circuit protector element to the element mount portion in a bridging manner across the cut. 
   Preferably, the busbars each has at least one electrode connection hole and the contact portions of the terminals each has a central hole, and wherein the contact portions are superimposed on the respective busbars with their holes aligned to each other. 
   Preferably, the element mount portions of the terminals each comprises a link piece at which the element mount portion is cut. 
   According to yet another aspect of this invention, there is provided a wire protector which comprises: a protector body including a trunk receiver for receiving trunk wires and a plurality of branch receivers continuous to the trunk receiver for receiving branch wires from the trunk wires, the plurality of branch receivers each including a terminal holder provided at a free end thereof and an expandable positional deviation absorbing portion arranged at an intermediate length thereof; and an open/close cover including a main cover for covering the protector body from the trunk receiver to the positional deviation absorbing portions of the branch receivers and a plurality of subcovers for covering the respective branch receivers from the terminal holder to the positional deviation absorbing portion, the main cover and the subcovers being rotatably linked via hinges to the protector body at positions corresponding to the trunk receiver and the respective branch receivers. 
   Preferably, the wire protector further comprises a wire letting-out portion provided at one end of the trunk receiver, the wire letting-out portion having a plurality of wire placement grooves, and a lit provided on the main cover corresponding to the wire letting-out portion. 
   Preferably, the positional deviation absorbing portion of each of the branch receivers comprises a pair of bent portions formed in a staggered manner in opposed side walls of the branch receiver and stoppers provided projecting in a staggered manner from one to the other of inner surfaces of the bent wall portions. 
   Preferably, the wire protector further comprises a positioning rib provided on the protector body or the open/close cover for positioning the wire protector in a mold. 
   The above and other objects, features and advantages of this invention will become apparent from the following description and the appended claims, taken in conjunction with the accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of a battery holder provided with battery connecting plates according to one embodiment of this invention; 
       FIG. 2  is a perspective view of one of the connecting plates in  FIG. 1 ; 
       FIGS. 3A and 3B  are connection diagrams obtained when batteries are connected in series by the connecting plates of  FIG. 1 , of which  FIG. 3A  shows a battery voltage detecting circuit and  FIG. 3B  shows a battery temperature detecting circuit; 
       FIG. 4  is an enlarged perspective view of an essential portion of the connecting plate of  FIG. 2 ; 
       FIG. 5  is an enlarged perspective view of a busbar, voltage detecting terminal and circuit protecting element of  FIG. 4 , shown in a connected condition; 
       FIG. 6  is a perspective view of a wire protector shown in an opened condition, which constitutes the battery-connecting plate of  FIG. 1 ; 
       FIG. 7  is a perspective view of a harness consisting of the wire protector of  FIG. 6 , and voltage detecting terminals and their connection wires held in the wire protector; 
       FIG. 8A  is a perspective view of a positional deviation absorbing portion of the wire protector of  FIG. 6 ; 
       FIG. 8B  is a plan view of the absorbing portion of  FIG. 8A , shown with a wire laid therethrough; 
       FIG. 9  is a perspective view of a terminal holder of the wire protector of FIG.  6  and voltage detecting terminals, shown in mutual relation; 
       FIG. 10  is a sectional view of the voltage detecting terminals about to be mounted in related receiver frames of the terminal holder of  FIG. 9 ; 
       FIG. 11  is a sectional view of a wire letting-out portion of the harness of  FIG. 7 ; 
       FIG. 12  is an explanatory view of a step for producing the battery-connecting plate of  FIG. 1 ; 
       FIG. 13  is an explanatory view of a step subsequent to that of  FIG. 12 ; 
       FIG. 14  is an explanatory view of the harness of  FIG. 7  being subjected to insert molding; 
       FIG. 15  is a plan view of the harness of  FIG. 7  set in a mold; 
       FIG. 16A  is an essential portion perspective view showing the busbar and the voltage detecting terminal in a connected condition in the connecting plate after insert molded; 
       FIG. 16B  is a view similar to  FIG. 16A , showing the circuit protecting element (fuse) about to be mounted; 
       FIG. 17A  is a sectional view taken along the line X—X of  FIG. 16B ; 
       FIG. 17B  is a sectional view taken along the line Y—Y of  FIG. 16B , shown with the fuse connected; 
       FIG. 18A  is an essential portion perspective view of one example of a conventional connecting plate for a battery holder; 
       FIG. 18B  is a sectional view of a fuse holder in  FIG. 18A ; 
       FIG. 19  is an essential portion perspective view of another conventional connecting plate for a battery holder; 
       FIG. 20  is an explanatory view of another example of a conventional method of connecting batteries; 
       FIG. 21A  is an explanatory view of a conventional fixing structure of wires by a molded resin plate; 
       FIG. 21B  is an explanatory view of upper and lower dies for the conventional fixing structure of  FIG. 21A ; and 
       FIG. 22  is an explanatory view of a conventional method of injecting resin into a mold. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Embodiments of this invention will now be described with reference to the attached drawings. 
   In  FIG. 1 , denoted A is a long cylindrical battery used as in an electric vehicle and B is a battery holder for receipt therein of a plurality of the batteries A. The battery A includes a main body  1 , female-thread nut type positive and negative electrodes  2   a ,  2   b  provided at opposite ends of the main body  1 , and a PTC element  3  secured to the outer periphery of the main body for checking the generation of heat from the battery A. The battery holder B consists of a rectangular parallelepiped frame body  4  and connecting plates  10 ,  10 ′ assembled at opposite sides of the frame body. The frame body  4 , in the illustrated example, includes a plurality of support plates  6 , each having a total of 21 (7 by 3) battery insertion holes  5 , stays  7  which hold the support plates  6  in a parallel arrangement with one another, and major walls  8  one of which is provided with bolts  9  for fastening the frame body  4  to a vehicle body. 
     FIG. 2  is a perspective view of the connecting plate  10 ,  FIGS. 3A and 3B  are connection diagrams of the batteries A connected in series with the connecting plates  10 ,  10 ′ and show a battery voltage detection circuit and a battery temperature detection circuit, respectively.  FIG. 4  is an essential portion enlarged view of the connecting plate  10 , and  FIG. 5  is a perspective view of a busbar, a voltage detecting terminal and a circuit protecting element in  FIG. 4  in a connected condition. 
   The connecting plate  10  includes a molded resin plate  11 , and a plurality of busbars  16 ,  16 ′ ( FIG. 15 ) for connecting the batteries and a wire protector  23  (FIG.  6 ), both fixed in the molded resin plate  11  by insert molding, which wire protector holds therein voltage detecting terminals  17  which are connected to the busbars  16 ,  16 ′ and their connection wires  22 . 
   The molded resin plate  11  has battery-connecting hexagonal windows  12  and square windows  12 ′ arranged in correspondence with the batteries A. A PTC element connecting square window  13  is juxtaposed to each window  12 ,  12 ′. Two fuse mount windows  14  are juxtaposed between desired ones of the hexagonal windows  12   1  and of the square windows  12   1 ′. Between neighboring square windows  13 ,  13  are embedded connection pieces  15  which connect the PTC elements  3  in series, in such a manner that their opposite ends  15   a , each with a connection hole  15   b , are exposed in the related square windows  13 . A fuse  21  is received in each fuse mount window  14 . 
   The busbar  16  is provided in ring-shaped plate form for flowing a large current, provided at its opposite ends with electrode connection holes  16   a , and has a length corresponding to the spacing between neighboring electrodes A. The busbar  16 ′ is U-shaped to connect the electrodes A in neighboring rows of electrodes. 
   Of the busbars  16  ( 16 ′), for example to those designated at  16   1  are connected voltage detecting terminals  17 . 
   The voltage detecting terminal  17  includes a contact portion  18  which is superimposed on the busbar  16 , and an element mount portion  19  and a wire connecting portion  20  continuous from the contact portion  18  in this order, and is integrally stamped out of an electrically conductive metallic plate, followed by bending. 
   The contact portion  18  is provided in a square or rectangular plate form of such size as to be superimposed on an end of the busbar  16 , and has a center bolt insertion hole  18   a  of the same diameter as the electrode connection hole  16   a  and a plurality of small diameter resin leakage checking holes  18   b  (eight in the illustrated example) surrounding the hole  18   a . The contact portion  18  has a resin leakage prevention piece  18   c  bent at one side thereof, and a continuous piece  18   d  bent downwardly at the side perpendicular to the side where the prevention piece  18   c  is provided, via which the element mount portion  19  is continuous to the contact portion  18 . 
   By abutting the resin leakage prevention piece  18   c  and the continuous piece  18   d  against respective edges at the end of the busbar  16 , the electrode connection hole  16   a  and the bolt insertion hole  18   a  have their centers aligned with each other. The edge  18   e  at the continuous piece  18   d  side of the contact piece  18  steps back to be located slightly rearwardly as compared with the continuous piece  18   d.    
   The element mount portion  19  includes a pair of lead connection pieces  19   a ,  19   a  and a link piece  19   b  which integrally links the lead connection pieces. The fuse  21  includes a fuse body  21   a  and leads  21   b  extending at opposite ends of the fuse body. Each lead connection piece  19   a  has a lead connection hole  19   c  for receiving the respective lead  21   b  of the fuse  21 . The element mount portion  19  is as a whole located at a one-step lower level than the contact portion  18  through the continuous piece  18   d  and one lead connection piece  19   a , and extends parallel to the end surface of the busbar  16 . The other lead connection piece  19   a  has a wire connection portion  20  with a wire barrel  20   a  and an insulator barrel  20   b  to which a covered wire  22  is at one end connected through crimping of the barrels  20   a ,  20   b . The wire  22  is wired at the other end side to a wire letting-out portion  36  at one side edge  11   a  of the molded resin plate  11 , at which the wires  22  are held at a predetermined spacing and let out of the molded resin plate  11 . 
   The element mount portion  19 , i.e., the pair of lead connection pieces  19   a ,  19   a  and their linking piece  19   b , as shown in  FIG. 16 , are exposed in the fuse mount window  14  of the resin plate  11 . 
   The link piece  19   b  of the element mount portion  19 , after molding the resin plate  11  by insert molding, is cut and removed through the fuse mount window  14 , and the leads  21   b  of the fuse  21  are inserted into the lead connection holes  19   c  of the respective lead connection pieces  19   a , followed by their soldering to the lead connection pieces to connect the fuse  21  to the voltage detecting terminal  17 . 
   The insert molding here is effected, apart from the busbars  16 ,  16 ′, with the voltage detecting terminals  17  and their connection wires  22 , as shown in  FIGS. 6 and 7 , held in advance in a predetermined layout in a wire protector  23 . 
   The wire protector  23  includes a protector body  24  and an open/close cover  42 , both made of synthetic resin. 
   The protector body  24  includes a trunk receiver  25  provided in wide U-shaped form for receiving a large number of trunk wires and a plurality of branch receivers  26  extending from the trunk receiver  25  and provided in narrow U-shaped form. In the illustrated example, there are provided a total of six branch receivers  26   1 ,  26   2  . . .  26   6  which intersect the trunk receiver  25  at right angles in T-shaped form at longitudinally opposite ends and an intermediate portion of the trunk receiver  25 . The cover  42  includes a main cover  42   0  and six subcovers  42   1 ,  42   2  . . .  42   6  for the trunk receiver  25  and for the branch receivers  26 . 
   Each branch receiver  26  has a positional deviation absorbing portion  27  at its intermediate length and a terminal holder  32  at its free end. 
   The positional deviation absorbing portion  27 , as shown in  FIGS. 8A and 8B , includes V-shaped (or U-shaped) bent portions  28 ,  28 ′ formed in a staggered manner in opposed side walls  26   a  at an intermediate length of the branch receiver  26  and a cutout  29  formed in the bottom wall  26   b  between the bent portions  28 ,  28 ′, so as to enable expansion and contraction to some degree. Further, there are provided three wire stoppers  30  which extend in a staggered manner from one to the other of the inner surfaces of the bent portions  28 ,  28 ′ and two wire separating pins  31  upstanding on the bottom wall  26   b , one on each side of the cutout  29 . 
   With such structure, as shown in  FIG. 8   b , the two wires  22  laid in the branch receiver  26  are separated from each other at both up- and downstream sides of the positional deviation absorbing portion  27  by the respective wire separating pins  31  and wired in the absorbing portion  27  with bent portions  22   a  formed by the cooperation of the bent portions  28 ,  28 ′ and the three wire stoppers  30 , thereby enabling the two wires  22  to smoothly follow the bending or stretching of the positional deviation absorbing portion  27 . 
   The terminal holders  32  provisionally hold the respective voltage detecting terminals  17  in position for insert molding. 
   In other words, the terminal holder  32 —which is provided in L-shaped form at the free end of the branch receiver  26  and extends in parallel to the trunk receiver  25 —includes, as shown in  FIG. 9 , two receiver grooves  33  of small width for receiving the wire connection portions  20  of the related voltage detecting terminals  17  and two receiver frames  34  of large width for receiving the related element mount portions  19  of the voltage detecting terminals  17 . Opposite side walls  33   b  at the receiver grooves  33  are provided with lock projections  35 . 
   Opposite side walls  34   b  at the receiver frames  34  are provided at their forward upper edges with cutouts  34   c  and on their rearward outer surfaces with recessed portions  34   d . Further, receiving seats  34   e  are provided inside each receiver frame  34 . 
   The downwardly extending continuous piece  18   d  of the voltage detecting terminal  17  is placed at its base in the cutout  34   c  so that the element mount portion  19  is disposed on the inside receiving seats  34   e , and the side edge  18   e , which is indented relative to the continuous piece  18   d , adjoins the recessed portion  34   d . Following the above, the subcover  42   1  ( 42   2  . . .  42   6 ) is closed so that its frame  49  is fitted in the related receiver frames  34  to hold the continuous piece  18   d  between the side walls  34   b ,  49   b , thereby to provide the fuse mound window  14  FIG.  4 ). 
   While in the example of  FIG. 9 , two receiver grooves  33  and two receiver frames  34  are juxtaposed in one terminal holder  32 , divided by respective central partition walls  33   a ,  34   a , it is also possible to provide one receiver groove  33  and receiver frame  34  in one terminal holder  32  as shown at the free end of the branch receiver  26   3  in FIG.  6 . 
   Reverting to  FIG. 6 , at one end of the trunk receiver  25  of the protector body  24  is provided a wire letting-out portion  36  which is, in the illustrated example, integral with the confluent outer side walls of the branch receivers  26   1  and  26   2 . The wire letting-out portion  36  includes wire placement grooves  37  at its central upper surface, positioning holes  38  at its left and right sides, and lock means at its one end, the lock means having a wire holding band  39  with a lock piece  40  at its free end and a lock portion  41  with an insertion hole  41   a  for the lock piece  40 . The lock piece  40 , as shown in  FIG. 11 , has a lock hole  40   a  for locking engagement therein of a resilient lock arm  41   b  located inside the insertion hole  41   a.    
   The trunk receiver  25  and each branch receiver  26  of the protector body  24  are provided at suitable positions on their opposite side walls  25   a ,  26   a  with lock projections  35  as are on the opposite side walls  33   b  of the receiver grooves  33  (FIG.  9 ), and a group of wire separating pins  31  are provided inside the trunk receiver  25  at predetermined spacings at the confluence with each branch receiver  26 . 
   The main cover  42   0  of the cover  42  covers the trunk receiver  25 , the wire letting-out portion  36  and each branch receiver  26  up to the positional deviation absorbing portion  27  and is rotatably linked via hinges  43  to the side wall opposite the wire letting-out portion  36 , i.e., to the outer confluent side walls of the branch receivers  26   5 ,  26   5 . The main cover  42   0  has resilient lock pieces  44  projecting at positions corresponding to the lock projections  35  of the trunk receiver  25  and each branch receiver  26 , the lock pieces  44  each having a lock hole  44   a  and engageable with the related lock projection  35 , and a lid  45  at its free end for the wire letting-out portion  36 . The lid  45  has a row of wire holding grooves  46  at its central portion which correspond to the wire placement grooves  37 , positioning pins  47  at its opposite sides corresponding to the positioning holes  38  and a hole  45   a  at its one end corresponding to the insertion hole  41   a  of the lock portion  41 . 
   The subcover  42   1  ( 42   2  . . .  42   6 ) covers the related branch receiver  26   1  ( 26   2  . . .  26   6 ) from the terminal holder  32  to the positional deviation absorbing portion  27 , includes a lid  48  for the receiver grooves  33  and the frame  49  fittable in the receiver frames  34 , and is rotatably linked via a hinge  43  to the terminal holder  32  as is the case with the main cover  42   0 . The lid  48  is provided at its opposite sides with resilient lock pieces  44  engageable with the corresponding lock projections  35 . The frame  49 , like the receiver frames  34 , is divided into two parts by a partition wall  49   a , has cutouts  49   c  on its opposite side walls  49   b  corresponding to the cutouts  34   c , and has those parts of the side walls  49   b  below the cutouts  49   c  formed as thin recessed walls  49   d.    
   The main cover  42   0  and each subcover  42   1  ( 42   2  . . .  42   6 ), as shown in  FIG. 7 , have positioning ribs  50  extending in their respective longitudinal directions on the front surface, which ribs serve to facilitate their positioning in a mold. These ribs  50  may be provided on the underside of the protector body  42 . 
   Incidentally, it is preferred that neighboring terminal holders  32 ,  32  on the left and right sides of the trunk receiver  25  be linked to each other with an expandable hinge  51  which is provided at the midpoint with a bent portion  51   a  so that each branch receiver  26   1 - 26   6  will be prevented from shaking or inclination. 
   The method of producing the connecting plate  10  by using the wire protector  23  will now be described. 
   Insulatingly covered wires  22  are first provided which are connected to voltage detecting terminals  17 . The wires  22  preferably have their insulating covers marked with different colors, patterns, stripes, signs or the like for the convenience of maintenance purposes and the like. The covered wires  22  are cut to have predetermined lengths and peeled at both ends. 
   The conductor  22   a  exposed at one end of the wire  22 , as shown in  FIG. 12 , is then connected to the wire connecting portion  20  of the voltage detecting terminal  17 , and the conductor  22   a  exposed at the other end of the wire  22  is connected to a female-type (or male-type) connector terminal  52  to provide a terminal-attached wire  22 ′. 
   The connector terminal  52  of each terminal-attached wire  22 ′, as shown in  FIG. 13 , is inserted at the final step of manufacturing process into a not-shown terminal receiving cavity of a connector housing  53  to be locked there through a locking means which is known and not shown. 
   Various terminal-attached wires  22 ′ thus provided are then, as shown in  FIG. 6 , placed in a predetermined layout on the wire protector  23  in an opened condition. 
   More specifically, the wire protector  23  is opened as shown in FIG.  6  and mounted on a not-shown workbench. Then, as shown in  FIGS. 9 and 10 , at the terminal holder  32 , the element mount portion  19  of the voltage detecting terminal  17  is placed on the receiving seats  34   e  inside the receiver frame  34  located on one side (left side on the drawing of  FIG. 10 ) of the central partition wall  34   a , with the wire connecting portion  20  placed on the receiver groove  33 . In this instance, the continuous piece  18   d  of the voltage detecting terminal  17  is fitted at its base in the cutout  34   c . The connection wire  22  is provisionally extended up to the positional deviation absorbing portion  27  of the related branch receiver  26 . 
   At the other side (right side on the drawing of  FIG. 10 ) of the central partition wall  34   a , the subcover  42   1  is raised upright relative to the nearby receiver frame  34  through the hinge  43  so as to form a clearance between the receiver frame  34  and the frame  49  of the subcover  42   1 . The voltage detecting terminal  17  can then be placed through the clearance inside the related receiver frame  34  in the same manner as mentioned above. 
   On closing the subcover  42   1  under the condition as mentioned above, the frame  49  fits in the receiver frames  34 , so that the edge  18   e  of each contact portion  18  comes into contact with the related recessed portion  34   d , and the continuous piece  18   d  of each voltage detecting terminal  17  is sandwiched between the related side wall  34   b  and recessed wall  49   d , resulting in the terminal holder  32  securely holding the terminal  17  in a horizontally-extended condition. The lock projections  35  engage with the respective resilient lock pieces  44  to lock the subcover  42   1 . 
   The above procedure is repeated to successively set the terminal-attached wire  22 ′ (voltage detecting terminal  17  and its connection wire  22 ) in the terminal holder  32  of each branch receiver  26 . 
   Then, as shown in  FIG. 8B , the wires  22  are wired through the positional deviation absorbing portion  27  of each branch receiver  26  in a weaving manner between the bent wall portions  28 ,  28 ′ and wire stoppers  30  to form bent portions  22   a . The wires  22  are lightly pulled toward the trunk receiver  25 , wired in a manner separated one by one through the wire separating pins  31  located in the trunk receiver  25 , and pushed into the respective wire placement grooves  37  of the wire letting-out portion  36  to provisionally hold the wires. 
   After completion of wiring each wire  22  in the branch receiver  26  and the trunk receiver  25 , the main cover  42   0  is closed, so that the positioning pins  47  of the lid  45  fit in the positioning holes  38  of the wire letting-out portion  36 , the resilient lock pieces  44  lockingly engage with the corresponding lock projections  35  of the protector body  25 , and the placement grooves  37  and the wire holding grooves  46  cooperate with each other to securely fix each wire  22 . The wires  22  let out through the wire letting-out portion  36 , as shown in  FIG. 11 , are bundled with the wire holding band  39 , followed by lockingly engaging its lock piece  40  into the insertion hole  41   a  of the lock portion  41 . 
   Thus, as shown in  FIG. 7 , voltage detecting terminals  17 , which are connected to the busbars  16 , and their connection wires  22  are held in a predetermined layout in the wire protector  23  to provide a harness P 0  for the connecting plate  10 ,  10 ′. 
   The harness P 0 , as shown in  FIGS. 14 and 15 , is then set in a mold for insert molding. 
   In other words, the lower die  54  is provided inside its cavity  55  with positioning lock pins  56 ,  57  for the busbars  16 ,  16 ′ and the PTC element connection pieces  15 , and at the four corners with collar locking pins  58 . The die  54  is further provided with positioning grooves (not shown) engageable with the positioning ribs  50  of the wire protector  23 . Denoted  59  is a placement recess for receiving therein the wire letting-out portion  36 . 
   After the busbars  16 ,  16 ′,  16 ″ and the PTC element connection pieces  15  as well as the collars  60  are accurately positioned through the respective lock pins  56 - 58  in the cavity  55 , the harness P 0  is set so that predetermined busbars  16  are in register with the related voltage detecting terminals  17 . 
   The registration, as mentioned hereinabove, is easily effected by superimposing the contact portion  18  of the voltage detecting terminal  17  on the end of the set busbar  16 ,  16 ′ such that its resin leakage prevention piece  18   c  and continuous piece  18   d  abut against the end edges of the busbar  16 ,  16 ′ perpendicular to each other (FIG.  5 ). 
   The upper die (not shown) is then set on the lower die  54 , and by effecting the insert molding under predetermined conditions, a molded piece P 1  is obtained which is shown in  FIGS. 16A and 16B . 
   The molded piece P 1  has the busbars  16 ,  16 ′ for connecting the electrodes  2   a ,  2   b  of batteries A and the PTC element connection pieces  15  embedded in its molded resin plate  11 . There are opened in the molded piece P 1  the battery-connecting hexagonal windows  12  and square windows  12  and the PTC element-connecting square windows  13 , and the element mount portion  19  of the voltage detecting terminal  17  is exposed in each fuse mount window  14 . 
   By mounting the fuse  21  in each fuse mount window  14  of the molded piece  14 , the finished connecting plate  10  is obtained. 
   In other words, the link piece  19   b  as shown in  FIG. 16A  which connects the pair of lead connection pieces  19   a ,  19   a  at each fuse mount window  14  is cut as shown in  FIG. 16B , and the leads  21   b  of the fuse  21  are inserted into the lead connection holes  19   c  of the lead connection pieces  19   a  and subjected to soldering to the respective lead connection pieces  19   a.    
   The resin leakage prevention piece  18   c , which is located adjacent the superimposed surfaces of the busbar  16  and the contact portion  18  and in a flow direction of molten resin, blocks the entrance of molten resin in between the superimposed surfaces during the insert molding, so that these surfaces are contacted with each other and held in that condition through the molding. 
   As shown in  FIG. 17A , if molten resin  61  leaks in between the busbar  16  and the contact portion  18 , such can be easily checked through the resin leakage checking hole  18   b , thereby preventing in advance defectives from being produced. 
   On the other hand, in case of no such resin leakage, the the link piece  19   b  located in the fuse mount window  14  of the molded piece P 1 , as shown in  FIG. 17B , is cut away, and the leads  21   b  of the fuse  21  are inserted into the respective lead connection holes  19  of the opposed lead connection pieces  19   a , followed by their soldering to the lead connection pieces  19   a . The finished connecting plate  10  is thus obtained. 
   Incidentally, the connecting plate  10 ′ used in a pair with the connecting plate  10 , which carries no voltage detecting terminals  17 , may be produced by a conventional insert molding method without using the wire protector  23 . 
   Reverting to  FIG. 1 , batteries A are inserted in succession into the respective battery insertion holes  5  of the battery holder B, with their positive and negative electrodes  2   a ,  2   b  reversed in an alternating manner, and then the connecting plates  10  and  10 ′ are set on the electrodes  2   a ,  2   b  prominent at opposite ends of the holder B, followed by fastening by turns the busbars  16  ( 16 ′) at their opposite ends to the respective positive and negative electrodes  2   a ,  2   b  of the batteries A with bolts  63  (FIG.  4 ). 
   The batteries A 1 , A 2 , A 3  . . . A n , as shown in  FIG. 3A , are thus connected in series by means of the busbars  16  ( 16 ′). Because a fuse  21  is connected, via the respective voltage detecting terminal  17 , to the single-pole busbar  16 ″ and the double-pole busbar  16  at their one end, by connecting their wires  22  to the not-shown ECU, the batteries A can be monitored for voltage in pairs and can be quickly replaced in units of two batteries in case of abnormal voltage. 
   Further, the PTC element  3  set on each battery A 1 , A 2  . . . A n  has leads (not shown) at its opposite-sides which are connected to opposite ends of the related connection piece  15  located in the connecting plate  10  ( 10 ′). In other words, not-shown screws are threaded in connection holes  15   b  at the opposite ends  15   a  of the connection piece  15 . The leads of the PTC element  3  as mentioned above are led out through respective passages  13   a  formed at a side in the square windows  13  and connected to the related connection piece  15  with the screws threaded in the connection piece  15 . 
   The PTC elements  3  of all the batteries A 1 , A 2  . . . A n , as shown in  FIG. 3B , are thus connected in series. Consequently, in case of an abnormal amount of heat generated in any of the batteries A, the resistance of the PTC element  3  at that battery A increases abruptly, resulting in the interruption of the check circuit. Thus, owing to the structure as mentioned above, abnormal voltage and abnormal generation of heat in the batteries A inside the battery holder B can be constantly monitored. 
   In the structure above, the layout of the busbars  16 ,  16 ′ in the connecting plate  10  is determined by the number and positions of the battery insertion holes  5  provided in the support plates  6  of the battery holder B as shown in FIG.  1 . The dimension between voltage detecting terminals  17 ,  17  also requires a high degree of accuracy. 
   In other words, in the connecting plate  10 , as shown in  FIG. 14  with the harness P 0  used as a substitute for the connecting plate  10 , the dimension X between the outer, remote voltage detecting terminals  17 ,  17 , the dimension Y between the inner terminals  17 ,  17 , the dimension Z between the vertically spaced terminals  17 ,  17  require a high degree of precision, and it is difficult to effect the insert molding in one step, with the dimensions between neighboring and remote ones of the large number of busbars  16 ,  16 ′ and wire-attached voltage detecting terminals  17  maintained to a given degree of accuracy. 
   According to this invention, however, the insert molding and the dimension control are made easy by the harness P 0  employing the wire protector  23 . 
   In other words, at the time of insert molding as shown in  FIGS. 14 and 15 , the busbars  16  are in advance accurately positioned through the lock pins  56  inside the die  54 . Accordingly, by setting the harness P 0  from thereabove, the voltage detecting terminals  17  can be accurately placed in position by one operation. The harness P 0 , which has the positional deviation absorbing portion  27  in each branch receiver  26  and the hinge  51  between neighboring terminal holders  32 ,  32 , is easily lengthwise and crosswise bendable, with the voltage detecting terminals  17  being fixedly maintained in their respective terminal holders  32 , so as to be set with ease. In this instance, because the connection wires  22  are protected in the wire protector  23 , they do not get tangled with one another, nor the voltage detecting terminals  17  are caused to get out of position. 
   The connection wires  22  of the voltage detecting terminals  17 , as mentioned above, are received and protected in the wire protector  23 , and thus, unlike the related art as shown in  FIG. 22 , do not directly come into contact with high-temperature molten resin during the insert molding. Therefore, no heat-resistant wires such as polyimide-covered wires are required. 
   The connection wires  22  of the voltage detecting terminals  17  are held in an orderly manner in the wire letting-out portion  36  of the wire protector  23 , and further bundled and fixed in position by the wire holding band  39 . Therefore, in the stage of the harness P 0 , during the insert molding and in the stage of the finished connecting plate  10 , the concentration of stress or biting by the upper and lower dies as explained in connection with  FIGS. 21A and 21B  are precluded. 
   In the connecting plate  10  of this invention, as will be apparent from a comparison of  FIGS. 16A and 16B , the lead connection pieces  19   a ,  19   a  of the element mount portion  19  to which the leads  21   b  of the fuse  21  are connected, are initially linked by the link piece  19   b . Therefore, during preparation of the harness P 0  and at the time of insert molding, the parts of the contact portion  18 , element mount portion  19  and wire connecting portion  20  can be handled as a single unit or voltage detecting terminal  17 . A reduction is thus made in the number of parts and man-hours, leading to a cost reduction. 
   Having now fully described the invention, it will be apparent to one of ordinary skill in the art that many changes and modifications can be made thereto without departing from the spirit and scope of the invention as set forth herein.