Patent Document

BACKGROUND OF THE INVENTION 
   This invention relates to an electric distribution box in which female-female terminals for electrically and mechanically connecting connection terminals of bus bars, distribution parts, etc., are received and supported in a case or a plate such as a board. 
   In many electric connection equipments of the type in which high voltage is dealt with within a limited space, electric wiring within the equipment is formed by installing strip-like bus bars. One example of such equipments is an electric distribution box. 
   For example, in a hybrid car, an electric car, a fuel cell car or the like, a battery, an ignition switch, an inverter, etc,. are provided via this electric distribution box, and an electromagnetic relay is operated based on an output signal from the ignition switch, and main power is transmitted to the inverter while a voltage sensor detects the condition of the battery (see, for example, JP-A-2004-282908 (Page 1, FIG. 1)). 
   One example of the construction of such electric distribution box will be described. For example, as shown in  FIG. 7 , the electric distribution box comprises a lower case z 1  having distribution part-receiving portions (not shown) respectively receiving distribution parts (such as fuses, an electromagnetic relay and a pressure sensor) and recess portions z 2 , bus bars z 4  each installed on the lower case z 1  and having a connection terminal z 5  received in an upstanding manner within the corresponding recess portion z 2 , female-female terminals z 3  which are completely received within the respective recess portions z 2 , and grip the respective connection terminals z 5 , and an upper case z 6  which is detachably fitted on the lower case z 1 , and has external connection terminal-inserting holes z 7  for the passage of external connection terminals of the distribution parts, etc., therethrough. As described above, for example, main power is transmitted to the inverter or the like by the ON/OFF operation of the ignition switch. 
   In the related electric distribution box, the upper case z 6  is fitted on the lower case z 1  having the female-female terminals completely received with the respective recess portions z 2  as described, and therefore the following problems have been encountered. 
   Namely, there are occasions when the external connection terminal-inserting hole z 7  and the corresponding female-female terminal z 3  are slightly displaced out of registry with each other from some cause, so that the external connection terminal can not be easily inserted into the female-female terminal z 3 . 
   For example, when the upper case is caused to strike against a working table or the like, the external connection terminal-inserting hole z 7  and the corresponding female-female terminal z 3  are slightly displaced out of registry with each other. 
   In such a case, the worker again carefully inserted the external connection terminal into the female-female terminal, and therefore there has been room for further improvement. 
   And besides, the side surfaces of the related female-female terminal are flat, and therefore there are occasions when the female-female terminal is inserted in a wrongly-oriented manner into the recess portion. In this case, the external connection terminal-inserting hole and a holding portion of the corresponding female-female terminal are completely displaced out of registry with each other, so that the external connection terminal, in some cases, has failed to be connected to the female-female terminal. 
   Therefore, as shown in  FIG. 8 , there has been proposed an electric distribution box in which external connection terminal-inserting holes z 10  for the passage of external connection terminals of distribution parts, etc., therethrough are formed in an upper case z 9 , and recess portions z 11  for respectively receiving female-female terminals z 3  are formed on this upper case in surrounding relation respectively to the peripheries of the holes z 10 , thereby preventing a holding portion of the female-female terminal z 3 , received in each recess portion z 11 , from being brought out of registry with the corresponding external connection terminal-inserting hole z 10 . 
   In the above electric distribution box, although the misregistration of the holding portion of each female-female terminal z 3  relative to the external connection terminal-inserting hole z 10  can be prevented, the following problem is encountered. 
   Namely, an upper surface of a lower case on which a plurality of bus bars are installed is flat, and therefore the shortest distance (that is, the creeping distance measured along an insulating surface) between the two conducting members, that is, each female-to-female terminal z 3  and each of those bus bars (other than the bus bar to which this female-female terminal z 3  is connected) disposed near to this female-female terminal z 3 , becomes smaller as compared with the related structure in which the recess portions are formed on the upper surface of the lower case, and as a result a problem has arises with the insulating performance. 
   SUMMARY OF THE INVENTION 
   It is therefore an object of this invention to provide an electric distribution box in which each external connection terminal-inserting hole is prevented from being disposed out of registry with a corresponding female-female terminal while securing a sufficient creeping distance between the female-female terminal and each of nearby bus bars, and besides wrong insertion of the female-female terminal into a recess portion is prevented, thereby enhancing the connecting reliability of external connection terminals. 
   The above object has been achieved by an electric distribution box of the present invention having the following technical features. 
   Namely, the invention provides an electric distribution box for containing a distribution parts, comprising: 
   a first case; 
   a second case that is attached to the first case; and 
   a female-female terminal that has holding portions for holding and electrically connecting mating terminals, 
   wherein a first recess portion is provided on one of the first and second cases, and receives a part of the female-female terminal; 
   wherein a second recess portion is provided on the other of the first and second cases, and receives a remaining part of the female-female terminal; and 
   wherein an inserting hole for inserting one of the mating terminal to contact with the female-female terminal is formed in at least one of the first and second recess portions. 
   Preferably, the female-female terminal has a convex portion formed on a side face thereof. An inserting direction-limiting portion is formed on at least one of the first and second recess portions, and is engaged with the convex portion to limit an inserting direction of the female-female terminal. 
   Preferably, the inserting direction-limiting portion is a recess portion that engages with the convex portion of the female-female terminal. 
   Preferably, a projecting portion is formed on either one of the first and second recess portions to guide one of the mating terminals to one of the holding portions of the female-female terminal. 
   Preferably, the female-female terminals includes a frame body having a generally rectangular shape when viewed from the top, and a strip-like resilient piece portion which is provided on the frame body, and is bent downwardly and upwardly so as to form an upper U-shaped portion and a lower U-shaped portion to form the holding portions. 
   In the electric distribution box of the invention, the first recess portions each for receiving part of the corresponding female-female terminal is formed at the one of the upper case (first case) and the lower case (second case), and the second recess portion for receiving the remainder of the female-female terminal is formed at the other of the upper and lower cases, and the female-female terminal is held by the upper and lower cases. Therefore, there can be provided the electric distribution box in which an external connection terminal-inserting hole, formed at one or both of the first and second recess portions, will not be disposed out of registry with the corresponding female-female terminal, thereby enhancing the connecting reliability of the external connection terminal. And besides, thanks to the provision of the first recess portion for receiving part of the female-female terminal, the creeping distance between the female-female terminal and the nearby bus bars is increased, so that a satisfactory insulating performance can be secured. 
   Furthermore, the convex portion, formed on the side surface of the female-female terminal, is engaged in the inserting direction-limiting portion formed at the first recess portion and the second recess portion, thereby limiting the inserting direction of the female-female terminal. Therefore, there can be provided the excellent electric distribution box in which the wrong insertion of the female-female terminal into the first and second recess portions is prevented. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The above objects and advantages of the present invention will become more apparent by describing in detail preferred exemplary embodiments thereof with reference to the accompanying drawings, wherein: 
       FIG. 1  is a vertical cross-sectional view of an important portion of a preferred embodiment of an electric distribution box A of the present invention. 
       FIG. 2  is a view taken along the line X-X of  FIG. 1 ; 
       FIG. 3  is an exploded, vertical cross-sectional view of the portion of  FIG. 1 ; 
       FIG. 4  is a perspective view showing an important portion of a lower case of the electric distribution box A of the embodiment; 
       FIG. 5  is a perspective view showing a condition in which female-female terminals are received in the lower case  2  of  FIG. 4 ; 
       FIG. 6  is a perspective view showing the appearance of the electric distribution box A of the embodiment; 
       FIG. 7  is a vertical cross-sectional view of a related electric distribution box; and 
       FIG. 8  is a vertical cross-sectional view of another related electric distribution box. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   A preferred embodiment of an electric distribution box of the present invention will now be described with reference to the accompanying drawings. The electric distribution box of this embodiment is used as an automotive part. A battery, an ignition switch, an inverter, etc., are provided via the electric distribution box, and an electromagnetic relay is operated based on an output signal from the ignition switch, and main power is transmitted to the inverter while a voltage sensor detects the condition of the battery, and the functions of the electric distribution box are well known. In the drawings, reference numeral  1  denotes female-female terminals, reference numeral  2  denotes a lower case, reference numeral  3  denotes bus bars, and reference numeral  4  denotes an upper case. 
   The electric distribution box A of this embodiment includes the female-female terminals  1 , the lower case  2 , and the upper case  4 . 
   The female-female terminal  1  is formed of an electrically-conductive metallic material. As shown in  FIGS. 1 and 2 , the female-female terminal  1  includes a frame body  11  (having a generally rectangular shape when viewed from the top) having an overlapping portion formed at one corner portion thereof. One side wall of the frame body  11  is bent back downwardly at an upper portion of the frame body  11 , and is further is bent back upwardly at a lower portion of the frame body  11  to thereby form a strip-like resilient piece portion  12  having generally U-shaped upper and lower portions. The female-female terminal  1  has a pair of holding portions  1   a  formed respectively between one of the opposite side walls of the frame body  11  and the resilient piece portion  12  and between the other side wall of the frame body  11  and the resilient piece portion  12 . A connection terminal  31  of the bus bar  3  (The bus bars  3  form circuits of the electric distribution box A) is inserted into one of the two holding portions  1   a  from the lower side, while a connection terminal  31 ′ of a distribution part or an external equipment is inserted into the other holding portion  1   a  from the upper side. 
   The frame body  11  has the overlapping portion formed at the one corner portion thereof (that is, at an upper left corner portion in  FIG. 2 ), the overlapping portion defining a convex portion  13 . 
   Each of the bus bars  3  is formed by blanking a strip-like member from an electrically-conductive metal sheet (such as a copper sheet) by a pressing machine or the like so that a desired wiring pattern can be provided, and then if necessary, a desired portion of the blanked portion is bent to form the connection terminal  31  for connection to the female-female terminal  1 . 
   The bus bars  3  are installed on the lower case  2  in such a manner that the connection terminals  31  (each formed by bending the end portion of the bus bar  3  upwardly) project upwardly. The lower case  2  has first recess portions  21  and distribution part-receiving portions (not shown) formed on an upper surface of the lower case  2 . The first recess portions  21  receive the respective female-female terminals  1  each gripping the connection terminal  31 , and the distribution part-receiving portions receives the respective distribution parts (such as fuses, an electromagnetic relay and a pressure sensor) forming the electric circuits of the electric distribution box A. Engagement portions  24  for engagement with respective retaining portions  43  of the upper case  4  (described later) are formed on side surfaces of the lower case  2 . 
   As shown in  FIGS. 2 to 4 , each first recess portion  21  has a generally rectangular shape when viewed from the top, and has an open portion  22  for installing the bus bar  3 . A projecting portion  25  is formed within the first recess portion  21 , and is disposed close to the open portion  22 . The projecting portion  25  supports the female-female terminal  1  in such a manner that the female-female terminal  1  is spaced upwardly from a bus bar installation surface  23  formed on the upper surface of the lower case  2 , and also the projecting portion  25  abuts against the bus bar  3  to thereby guide the connection terminal  31  upwardly. 
   The first recess portion  21  (having the generally rectangular shape when viewed from the top) has an inserting direction-limiting portion  26  (into which the convex portion  13  of the female-female terminal  1  is inserted) formed in an inner side surface thereof, and this inserting direction-limiting portion  26  serves to prevent wrong insertion of the female-female terminal  1  into the first recess portion  21   
   The first recess portion  21  is formed into such a predetermined depth that a generally upper half portion of the female-female terminal  1  projects outwardly from the first recess portion  21  when the female-female terminal  1  is received in the first recess portion  21 . Also, the inner periphery of the first recess portion  21  has such a predetermined size that the female-female terminal  1  can be inserted and fitted thereinto. 
   Thanks to the provision of the first recess portions  21 , a sufficient creeping distance is secured between each female-female terminal  1  and each of the nearby bus bars (that is, those bus bars other than the bus bar to which this female-female terminal  1  is connected), thereby securing a satisfactory insulating performance. 
   Second recess portions  41  for respectively receiving the generally upper half portions of the female-female terminals  1  are formed in a lower surface of the upper case  4 . External connection terminal-inserting holes  42  for the passage of the downwardly-extending external connection terminals  31 ′ of the distribution parts and external equipments therethrough are formed respectively in predetermined portions of the upper case  4 . The retaining portions  43  for engagement with the respective engagement portions  24  of the lower case  2  are formed on side surfaces of the upper case  4  so that the upper case  4  can be detachably engaged with the lower case  2 . 
   A second inserting direction-limiting portion  44  is formed within each second recess portion  41  so as to be continuous with the corresponding inserting direction-limiting portion  26  formed at the lower case  2 , and the female-female terminal  1  can be inserted into this limiting portion  44 . 
   Next, a procedure of assembling the electric distribution box A of this embodiment, having the above construction, will be described. First, the distribution parts are received respectively in the distribution part-receiving portions (not shown) of the lower case  2 , and the bus bars  3  are installed on the bus bar installation surface  23 , thereby forming the desired circuits on the lower case  2 . At this time, the connection terminal  31  of the bus bar  3  is brought into abutting engagement with the projecting portion  25  of the first recess portion  21 , thereby positioning the connection terminal  31  received in a projecting manner within the first recess portion  21 . 
   Then, while confirming the orientation of the female-female terminal  1  so that its convex portion  13  can be engaged in the inserting direction-limiting portion  26 , each female-female terminal  1  is inserted the corresponding first recess portion  21  (in which the connection terminal  31  of the bus bar  3  is received in a projecting manner) until the female-female terminal  1  is brought into abutting engagement with the projecting portion  25 . At this time, the connection terminal  31  of the bus bar  3  is fitted in the holding portion  1   a,  and the female-female terminal  1  is received in the first recess portion  21 . This received condition is shown in  FIG. 5 . 
   Then, the upper case  4  is fitted on the lower case  4  in such a manner that the retaining portions  43  of the upper case  4  are engaged respectively with the engagement portions  24  of the lower case  2 . At this time, the generally upper half portion of the female-female terminal  1  is received in the second recess portion  41  in such a manner that the generally upper half portion of the convex portion  13  of the female-female terminal  1  is engaged in the second inserting direction-limiting portion  44  formed within the second recess portion  41 . 
   Then, the external connection terminals  31 ′ of the distribution parts and external equipments are passed respectively through the external connection terminal-inserting holes  42  formed in the upper case  4 , and as a result each of these external connection terminal  31 ′ is inserted into the other holding portion  1   a  opposed to the holding portion  1   a  in which the connection terminal  31  of the bus bar  3  is fitted. Therefore, the external connection terminals  31 ′ of the distribution parts and external equipments are electrically connected to the respective connection terminals  31  of the bus bars  3  via the respective female-female terminals  1 . 
   As described above, in the electric distribution box A of this embodiment, the first recess portions  21  for respectively receiving the generally lower half portions of the female-female terminals  1  are formed on the lower case  2 , while the second recess portions  41  for respectively receiving the generally upper half portions of the female-female terminals  1  are formed at the upper case  4 . The female-female terminals  1  are held by the upper case  4  and the lower case  2 , thereby eliminating a fear that the external connection terminal-inserting holes  42  are disposed out of registry with the respective female-female terminals  1 , and at the same time the sufficient creeping distance is secured, thereby positively insulating each female-female terminal  1  from the nearby bus bars. 
   And besides, the convex portion  13  is formed on the female-female terminal  1 , and the inserting direction-limiting portions  26  and the second inserting direction-limiting portions  44  (in which the convex portions  13  can be engaged) are formed in the lower case  2  and the upper case  4  so as to limit the inserting direction of each female-female terminal  1 , thereby preventing the wrong insertion of the female-female terminal  1  into the first and second recess portions  21  and  41 . 
   Although the electric distribution box A of this embodiment has been described above, this electric distribution box is merely one example of preferred embodiments of the invention, and therefore the invention is not limited to the above embodiment, and various modifications can be made without departing from the subject matter of the invention. 
   For example, in the above embodiment, although the convex portion  13  is defined by the overlapping portion formed at the one corner portion of the frame body  11  (that is, the upper left corner portion in  FIG. 2 ), the shape and disposition of the convex portion are arbitrary and are not limited in so far as it can limit the inserting direction of the female-female terminal. 
   Although the invention has been illustrated and described for the particular preferred embodiments, it is apparent to a person skilled in the art that various changes and modifications can be made on the basis of the teachings of the invention. It is apparent that such changes and modifications are within the spirit, scope, and intention of the invention as defined by the appended claims. 
   The present application is based on Japan Patent Application No. 2005-117654 filed on Apr. 15, 2005, the contents of which are incorporated herein for reference.

Technology Category: 5