Abstract:
A terminal structure of a flat circuit body includes: a flat circuit body having a plurality of conductors and insulating films for sandwiching the plural conductors; a plurality of connection terminals connected and fixed to the plural conductors respectively; a connector housing having a plurality of terminal housing chambers for housing the plural connection terminals; and a housing cover fixed to the connector housing, the housing cover having partition walls for separating terminal vicinity portions of the conductors in the flat circuit body and connection portions of the connection terminals from other adjacent conductors and other connection terminals in next side thereof. In the construction, the housing cover is attached so as to cover the terminal vicinity portions of the flat circuit body and the connector housing integrally.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a terminal structure of a flat circuit body such as a flexible flat cable (FFC) and a flexible print circuit (FPC). 
     2. Description of the Related Art 
     In general, in the case where circuits are electrically connected with one another by using a flat circuit body. a connector is attached to a terminal of the flat circuit body, and this connector is connected to a mating connector. As such a terminal structure of a flat circuit body, a technique shown in FIG. 1, which is disclosed in Japanese Patent Application Laid-Open No. 6-208873, is known. 
     As shown in FIG. 1, FPC  1  as a flat circuit body is such that a plurality of conductors  2  are sandwiched by insulating films, and portions of the conductors  2  in a vicinity of a terminal portion of the FPC  1  are exposed, and contacts (connection fittings)  3  are caulked to be coupled to conductor terminals  2   a . The contacts  3  are housed and arranged and supported in contact arrangement spaces  4   a  of a connector housing  4 . 
     However, in the above-mentioned terminal structure of the flat circuit body, since connection portions (piercing connection portions) between the contacts  3  housed in the connector housing  4  and the conductor terminals  2   a  are exposed, short circuit might occur due to contact such as adhesion of foreign matters. Moreover, in the case where condensation occurs on or water drops adheres to the connection portions between the contacts  3  and the conductor terminal  2   a , there arises a problem that a leak current is generated. 
     In addition, in the above terminal structure, fixing between the FPC  1  and the connector housing  4  is obtained by fixing between the contacts  3  and the connector housing  4 . For this reason, there arises a problem that a coupling strength between the contacts  3  and the FPC  1  is weak. 
     Since a tension from the FPC  1  is transmitted directly to the contacts  3 , the contacts  3  are likely to move in the connector housing  4 , and thus contact resistance might increase. 
     SUMMARY OF THE INVENTION 
     Therefore, the present invention is devised taking the above circumstances into consideration, and it is an object of the present invention to provide a terminal structure of a flat circuit body which is capable of preventing short circuit between conductors due to moisture, foreign matters or the like and obstructing movement of connection terminals so as to prevent a fluctuation In contact resistance. 
     A first aspect of the present invention provides a terminal structure of a flat circuit body, comprising: a flat circuit body includes; a plurality of conductors arranged with predetermined intervals; and insulating films for sandwiching the plural conductors so as to fix the conductors; a plurality of connection terminals connected and fixed to the plural conductors respectively; a connector housing having a plurality of terminal housing chambers for housing the plural connection terminals; and a housing cover fixed to the connector housing, the housing cover having partition walls for separating terminal vicinity portions of the conductors in the flat circuit body and connection portions of the connection terminals from other adjacent conductors and other connection terminals in next side thereof, wherein the housing cover is attached so as to cover the terminal vicinity portions of the flat circuit body and the connector housing integrally. 
     Therefore, in the invention having such a structure, the terminal portion of the flat circuit body is covered by the housing cover, and the connection portions between the conductors and the connection terminals are separated from one another by the partition walls. As a result, adhesion of foreign matters or water drops is prevented so that the conductors or the connection terminals can be prevented from short-circuiting. The partition walls gain a creeping distance between the conductors even if electrically conductive fluid such as water drops adheres. For this reason, generation of a leak current can be prevented. 
     A second aspect of the present invention provides the terminal structure of the flat circuit body according to the first aspect, wherein: the housing cover has a lower cover, an upper cover and hinge portion for pivoting the upper cover with respect to the lower cover; and the partition walls are provided in such a manner that the partition wall formed on the lower cover and the other partition wall formed on the upper cover are stuck together. 
     Therefore, in the invention according to the second aspect, since the housing cover has the lower cover and the upper cover via the hinge portions, the connector housing and the terminal portion of the flat circuit body are sandwiched to be surrounded by the lower cover and the upper cover. As a result, the terminal structure can be formed easily. 
     A third aspect of the present invention provides the terminal structure of the flat circuit body according to the second aspect, wherein rear end portion of the housing cover sandwiches the terminal vicinity portions of the flat circuit body. 
     Therefore, in the invention according to the third aspect, the rear end portions of the housing cover sandwich the terminal vicinity of the flat circuit body. Even if a tension or a stress from the outside is transmitted via the flat circuit body, since the terminal vicinity of the flat circuit body is sandwiched and supported by the housing cover, the tension or stress is not transmitted to the connection terminals in the connector housing. As a result displacement or movement of the connection terminals can be prevented. For this reason, increase or fluctuation in contact resistance at the connection terminals can be prevented. 
     A fourth aspect of the present invention provides the terminal structure of the flat circuit body according to the third aspect, wherein: a stepped portion is formed on one of a rear end portion of the lower cover and a rear end portion of the upper cover; and a pier portion which is substantially stuck with the stepped portion in offset state is formed on the other of the rear end portion of the lower cover and the rear end portion of the upper cover. 
     Therefore, in the invention according to the fourth aspect, the terminal vicinity of the flat circuit body can be held easily only by sandwiching the terminal vicinity of the flat circuit body by means of the lower cover and the upper cover. Moreover, the terminal portion of the flat circuit body is sandwiched by the stepped portion and the pier portion so as to be sandwiched on surfaces of at least two directions. For this reason, displacement of the conductors to an extended direction can be prevented securely. 
    
    
     BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS 
     The above and further objects and novel features of the present invention will more fully appear from the following detailed description when the same is read in conjunction with the accompany drawings, in which: 
     FIG. 1 is an exploded perspective view showing a prior terminal structure of a flat circuit body; 
     FIG. 2 an exploded perspective view showing a terminal structure of a flat circuit body according to an embodiment of the present invention; 
     FIG. 3 is a vertical sectional view showing a state that the terminal structure of the embodiment is cut in a front-rear direction: 
     FIG. 4 is a sectional view taken along line IV—IV of FIG. 3; and 
     FIG. 5 is a sectional view taken along line V—V of FIG.  3 . 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     There will be detailed below a terminal structure of a flat circuit body according to the present invention based on an embodiment shown in the drawings, Here, in the present embodiment, a flexible flat cable (hereinafter, FFC) is used as a flat circuit body. 
     As shown in FIGS. 2 and 3, the terminal structure of the flat circuit body according to the present embodiment is substantially composed of FFC  11 , a plurality of connection terminals  12  connected to the FFC  11 , a connector housing  13  for housing and fixing the connection terminals  12 , and a housing cover  14 . 
     The FFC  11  is constituted so that a plurality of long conductors  15  which are rolled and made of copper foil or the like are sandwiched between a pair of base films (see FIG. 5)  16 ,  16  by using adhesive in parallel with predetermined intervals. At a terminal of the FFC  11 , as shown in FIGS. 2 and  3 , the conductors  15  are piercing-connected with rear end portions of the connection terminals  12  by means of connection portions  30 . The connection terminals  12  whose rear end portions are connected to the terminals of the conductors  15  are housed in cavity portions  13 A formed in the connector housing  13  so as to be engaged with and fixed to terminal engagement portions  13 B provided on upper portions of the cavity portions  13 A. 
     As mentioned above, the connector housing  13  is provided with a plurality of cavity portions  13 A as terminal housing chambers and with a cover engagement portion  17 , which engages with the housing cover  14 , at an upper portion. This cover engagement portion  17  hangs across the upper portion of the rear end side of the connector housing  13  in a widthwise direction. Moreover, an engagement spring piece  13 C which is extended to the rear end side integrally with the upper portion of the front end side of the connector housing  13  in a state that it lifts from the upper surface. This engagement spring piece  13 C is used for coupling with a mating connector, not shown. 
     Next, there will be explained below a structure of the housing cover  14 . As shown in FIG. 2, the housing cover  14  has a lower cover  19  and an upper cover  20  between which hinge portions  18 ,  18  intervene. A pier portion  21  is protruded from a rear end upper portion of the lower cover  19  across its widthwise direction. Correspondingly, a stepped portion  22  for housing the pier portion  21  is formed on a rear end lower surface of the upper cover  20  (the hinge portions  18  are bent so that the lower surface is formed). This stepped portion  22  is composed of an upper wall surface portion  22 A which is opposed to an upper surface of the pier potion  21  via a slight distance when the hinge portions  18 ,  18  are bent and the lower cover  19  is mounted to the upper cover  20 , and a side surface portion  22 B which is opposed to a front surface of the pier portion  21  via a slight distance. Moreover, engagement protrusions  21 A are formed respectively on both side surfaces of the pier portion  21 . Correspondingly, side walls  23 ,  23  are formed on both rear end side surfaces of the upper cover  20 , and engagement holes  23 A which engage with the engagement protrusions  21 A of the pier portion  21  are formed respectively on the side walls  23 . 
     In addition, side walls  24 ,  24  are arranged in a standing manner respectively on both front end side portions of the lower cover  19 , and engagement protrusions  24 A are formed respectively on outer side surface upper portions of the side walls  24 . Correspondingly, side walls  25 ,  25  are formed on both front end sides of the upper cover  20 . Engagement holes  25 A which engage with the engagement protrusions  24 A are formed respectively on the side walls  25 . An engagement piece  26 , which is engaged with the cover engagement portion  17  when attached to the connector housing  13 , is formed on a front end portion of the upper cover  20 . 
     Further, a plurality of partition walls  27  are arranged in a standing manner on the lower cover  19  in parallel along the front-rear direction. Meanwhile, partition walls  28  corresponding to the partition walls  27  formed on the lower cover  19  are formed on the upper cover  20 . Moreover, conductor supporting protrusions  29  with similar height to that of the partition walls  28  are formed in grooves which are formed by arranging the partition walls  28  on the upper cover  20  in a standing manner. Here, a number of the partition walls  27  and  28  is set so as to be the same as a number of wall portions composing the cavity portions  13 A of the connector housing  13 . When the lower cover  19  is attached to the upper cover  20 , the partition walls  27  the partition walls  28  are stuck together correspondingly so that connection spaces whose number is the same as a number of the cavity portions  13 A of the connector housing  13  are formed. 
     As shown in FIGS. 3 and 4. the rear end portions of the connection terminals  12  piercing-connected to the conductors are housed in the spaces formed in the housing cover  14 . Moreover, as shown in FIG.  2 . the vicinity of the end portion of the FFC  11  is also sandwiched by the housing cover  14 . More concretely, as shown in FIG. 2, the terminal vicinity of the FFC  11  is sandwiched by the pier portion  21  of the lower cover  19  and the stepped portion  22  of the upper cover  20  as shown in FIG.  5 . For this reason, the pier portion  21  and the stepped portion  22  sandwich the FFC  11  so as to serve as a strain relief for preventing slipping and movement of the PFC  11 . 
     Next, there will be explained below a procedure for forming the terminal structure of the flat circuit body according to the present embodiment. At first as represented by a thick arrow a in FIG. 2, the connector housing  13 , to which the FFC  11  and the connection terminals  12  are attached, is placed on the lower cover  19 . Thereafter, the upper cover  20  is pivoted on the hinge portions  18 .  18  as shown by a thick arrow b in the drawing and the upper cover  20  is matched with the lower cover  19  so that the connector housing  13  is surrounded by the housing cover  14 . At this time, the engagement piece  26  formed on the front end portion of the upper cover  20  is engaged with the cover engagement portion  17  of the connector housing  13  so as to prevent the connector housing  13  from coming out of the housing cover  14 . Moreover, the lower cover  19  and the upper cover  20  are mounted and fixed to each other in such a manner that the engagement protrusions  21 A and the engagement holes  23 A engage with one another and the engagement protrusions  24 A and the engagement holes  25 A engage with one another. 
     As mentioned above, In the terminal structure of the flat circuit body according to the present embodiment, the rear end portions of the connection terminals  12  exposed at the terminal of the FFC  11  are independently separated from one another by the partition walls  27  and  28  of the housing cover  14 . For this reason, foreign matters or water drops can be prevented from adhering to between the rear end portions of the connection terminals  12  or between the conductors  15 , and occurrence of short circuit can be prevented. Moreover, if fluid such as water drops comes thereinto, the partition walls  27  and  28  are formed so that a creeping distance can be gained. As a result, a leak current can be prevented from being generated. 
     In addition, in the above-mentioned present embodiment, if an external force is transmitted to the housing cover  14  via the FFC  11 , since the pier portion  21  of the lower cover  19  and the stepped portion  22  of the upper cover  20  sandwich and hold the FFC  11 , the external force is not transmitted to the inside. The connection terminals  12  are prevented from being displaced and the connection points are not moved. As a result, increase or fluctuation in contact resistance can be prevented. 
     The embodiment was explained, but the present invention is not limited to this, and various modifications can be made within a scope of the gist of the structure. For example, in the above-mentioned embodiment, the FFC  11  was used as the flat circuit body, but FPC may be used. 
     The entire contents of Japanese Patent Application P2000-20516 (filed on Jan. 28, 2000) are incorporated herein by reference. 
     Although the invention has been described above by reference to certain embodiments of the invention, the invention is not limited to the embodiments described above. Modifications and variations of the embodiments described above will occur to those skilled in the art, in light of the above teachings. The scope of the invention is defined with reference to the following claims.