Abstract:
In a fuse connection box, a pair of terminal fittings is inserted through one end of a housing and a fuse is inserted from the other end of the housing to connect input and output terminals of the fuse with a pair of the terminal fittings. The housing includes a pair of partitioning walls spaced from each other at a certain interval. A pair of terminal accommodation chambers are surrounded by the partitioning walls and a peripheral wall of the housing. A pair of lances, to be locked to locking portions of the terminal fittings, is provided at distal ends of a pair of the partitioning walls. A reinforcing connection frame connects a pair of the partitioning walls to each other, and may strengthen the partitioning walls against deformation and/or help reduce entry of water into the housing. A flexing restraining rib projects from an upper surface of the reinforcing connection frame, to prevent excessive deformation of the frame.

Description:
[0001]     This application claims priority from Japanese Patent Application 2005-254899, filed Sep. 2, 2005, the entire contents of which are incorporated herein by reference.  
       BACKGROUND  
       [0002]     The present invention relates to a fuse connection box. A fuse may be removably inserted from one side of the fuse connection box and terminal fittings connected to ends of electric wires disposed in a car body may be inserted from the other side of the fuse connection box to connect the terminal fittings and input and output terminals of the fuse to each other. The fuse connection box is preferably used to accommodate a fuse which has a small height and approximately a quadrangular shape. Input and output terminals of the fuse connection box are exposed from cut-outs disposed at left and right sides of a fuse body made of resin.  
         [0003]     A fuse connection box of this kind is proposed and disclosed in Japanese Patent Application Laid-Open No. 2004-158256 (JP-A-2004-158256). As shown in  FIGS. 6 and 7 , a pair of female terminals  3  crimped to the ends of a pair of electric wires W is inserted into a pair of the terminal accommodation chambers  2  of the fuse connection box  1  from openings formed at one end of the fuse connection box  1 . Locking portions  4   a  provided at the free-end side of a pair of the lances  4  projected inside the terminal accommodation chamber  2  or locked to locking stepped portions  3   a  formed on the female terminals  3 . The space communicating with the distal side of the terminal accommodation chambers  2  of the fuse connection box  1  is formed as a fuse accommodation chamber  5 . A fuse  6  is removably inserted into the fuse accommodation chamber  5 . Thereby the input terminal  6   a  and the output terminal  6   b  of the fuse  6  and the terminals  3  are connected with each other by fitting the terminals  6   a,    6   b  and the terminals  3  to each other.  
         [0004]     When the terminals are removed from the fuse connection box  1 , an unlocking jig (not shown) is inserted into the fuse connection box  1  from the free end side of the lances  4  to unlock the locking stepped portions  3   a  from the locking portions  4   a  by flexing the locking portions  4   a.  To prevent the lances  4  from flexing excessively, a contact member  7  is mounted between the lances  4 .  
       SUMMARY  
       [0005]     As shown in  FIG. 7B , in the construction disclosed in JP-A-2004-158256, both ends of the contact member  7  are fixed to a partitioning wall  8 . Thus when a force is applied to the central portion of the contact member  7 , the contact member  7  deforms in the shape of a bow which may allow the lances to flex excessively and possibly break. Further, because the contact member  7  is mounted in the penetration space of the opening of the fuse connection box  1  between the lances  4 , water may be able to penetrate into the fuse connection box  1  from the lower end opening of the fuse connection box  1 . If water penetrates into the fuse connection box  1 , the water may moisten the fuse  6  and/or the terminals  3 . Thus, the construction disclosed in JP-A-2004-158256 may exhibit poor waterproof performance.  
         [0006]     The present invention has been made in view of the above-described problem. Accordingly, it is an object of exemplary embodiments of the present invention to provide a fuse connection box having an improved mechanism for preventing a pair of lances from excessively elastically deforming when terminal fittings connected to ends of a pair of electric wires are unlocked from the lances to prevent the lances from being broken. It is another object of exemplary embodiments of the present invention to provide a fuse connection box having improved waterproof performance.  
         [0007]     To achieve these objects, embodiments of the present invention provide a fuse connection box in which a pair of terminal fittings connected to ends of a pair of electric wires is inserted into a terminal accommodation space from a terminal insertion opening disposed at one end of a connection housing, and a fuse is inserted into a fuse accommodation space from a fuse insertion opening at the other end of the connection housing and mounted in the fuse accommodation space to connect input and output terminals of the fuse with a pair of the terminal fittings respectively mounted on the ends of the electric wires.  
         [0008]     The housing of the fuse connection box includes a pair of partitioning walls disposed upward from the terminal insertion opening inside the terminal accommodation space, with the partitioning walls spaced from each other at a certain interval; a pair of terminal accommodation chambers surrounded by the partitioning walls and a peripheral wall of the housing; a pair of lances, to be locked to locking portions of the terminal fittings, which is provided at distal ends of a pair of the partitioning walls; a reinforcing connection frame connecting the pair of partitioning walls to each other; and a flexing restraining rib projected from an upper surface of the reinforcing connection frame.  
         [0009]     In the above-described construction, when the lances are flexed by the unlocking jig inserted into the fuse accommodation space to unlock the terminals from the lances respectively, the lances may be prevented from being excessively flexed. This is because the lances are formed at the distal ends of a pair of the partitioning walls and because the opposed partitioning walls are connected to each other with the reinforcing “H”-shaped connection frame. Further, the flexing restraining rib projects from the reinforcing connection frame. When the lances flex beyond a certain extent, the lances contact the flexing restraining rib, which prevents the lances from being excessively flexed. Because the flexing restraining rib is firm and projects from the upper surface of the reinforcing connection frame, the flexing restraining rib is prevented from being deformed by the elastically deformed lances. Further, the integration of the lances with the partitioning wall contributes to miniaturization of the fuse connection box.  
         [0010]     The reinforcing connection frame connecting the pair of partitioning walls to each other may serve as a waterproof wall.  
         [0011]     In the above-described construction, the reinforcing connection frame shuts out water which has penetrated into the fuse connection box from the opening formed through the lower end of the housing between the partitioning walls, thereby preventing the water from wetting the fuse or the terminals, and thereby enhancing the waterproof performance of the fuse connection box.  
         [0012]     The reinforcing connection frame may be spaced at a certain interval from proximal positions of the pair of lances. The flexing restraining rib projects from a central portion of the reinforcing connection frame, with a gap formed between the flexing restraining rib and the lances disposed at both sides of the flexing restraining rib.  
         [0013]     In the above-described construction, the reinforcing connection frame is spaced at a required dimension from the proximal end of the lances. Thus, in unlocking the terminal from the lances with the unlocking jig, the lances flex only to such an extent that the lances are capable of returning to their original state. Further, the elastic deformation of the lances does not affect the position where the reinforcing connection frame is formed. Consequently it is possible to relieve a stress generated at a boundary between the reinforcing connection frame and the partitioning walls and reliably prevent breakage of the lances disposed at the distal sides of the partitioning walls.  
         [0014]     If the flexing restraining rib is rod-shaped, a sufficient space is provided between the lances and the flexing restraining rib to allow the lance to flex in the space.  
         [0015]     The reinforcing connection frame is disposed in the vicinity of proximal positions of the pair of lances. The flexing restraining rib may be sectionally mountain-shaped and project from the central portion of the reinforcing connection frame, with a gap between the flexing restraining rib and the lances gradually increasing toward the free ends of the lances.  
         [0016]     In the above-described construction, when the flexing restraining rib contacts the lances, the elastically deformed lances make a surface contact with the inclined surface of the flexing restraining rib and are held thereby because the flexing restraining rib is mountain-shaped. Therefore the stress caused by flexing the lances should not concentrate on one point of the lances which may reduce the possibility of breaking the lances.  
         [0017]     Instead of the mountain-shaped flexing restraining rib, the rod-shaped flexing restraining rib may be projected from the central portion of the reinforcing connection frame.  
         [0018]     The fuse to be accommodated in the fuse accommodation space has an input terminal and an output terminal parallel therewith, both exposed from cut-outs disposed at left and right sides of the rectangular fuse body. The height of the fuse accommodation space is so set that the fuse body can be fitted therein.  
         [0019]     Because the input terminal and the output terminal are not longitudinally projected from the fuse body, the height of the fuse can be made smaller than a fuse in which the terminals longitudinally project from the fuse body. Consequently, the fuse connection box can be made compact and lightweight.  
         [0020]     As apparent from the foregoing description, in the fuse connection box of embodiments of the present invention, during disconnection of the terminals connected with of the electric wires from the fuse connection box, the lances are flexed by the unlocking jig inserted into the fuse accommodation space to unlock the terminals from the lances. In this unlocking operation, the lances may be less likely to be excessively flexed and/or broken because the lances are formed at the distal end of the partitioning walls, which are connected to each other with the reinforcing connection frame. In addition, the flexed lances may contact the flexing restraining rib projecting from the reinforcing connection frame, which may also reduce the possibility of the lances being excessively flexed.  
         [0021]     The partitioning walls may be connected with each other by the reinforcing connection frame to form a waterproof wall therebetween. The reinforcing connection frame shuts out water which has penetrated into the fuse connection box through the opening formed in the lower peripheral wall of the housing between the partitioning walls, thereby preventing the water from wetting the fuse and the terminals. This helps reduce the possibility of corrosion.  
         [0022]     These and other objects, advantages and features are described in and apparent from the following detailed description. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0023]     Exemplary embodiments will be described in connection with the attached drawings, in which like numerals represent like ports, and which:  
         [0024]      FIG. 1  is a sectional view showing a fuse connection box of a first embodiment of the present invention;  
         [0025]      FIG. 2  is a main part-enlarged sectional view seen in a direction shown with an arrow (from the left side) of  FIG. 1 ;  
         [0026]      FIG. 3  is a sectional view showing a state in which a fuse and terminal fittings connected to ends of electric wires are inserted into the fuse connection box of the first embodiment to connect the fuse and the terminal fittings to each other;  
         [0027]      FIG. 4  is a sectional view showing an operation of unlocking terminal fittings connected to the ends of electric wires from lances provided inside the fuse connection box;  
         [0028]      FIG. 5  is a sectional view showing a fuse connection box of a second embodiment of the present invention;  
         [0029]      FIG. 6  is a perspective view showing a conventional fuse box;  
         [0030]      FIG. 7A  is a sectional view showing the conventional fuse box shown in  FIG. 6 ; and  
         [0031]      FIG. 7B  is a bottom view showing the conventional fuse box shown in  FIG. 6 . 
     
    
     DETAILED DESCRIPTION OF EMBODIMENTS  
       [0032]     Exemplary embodiments of the present invention will be described below with reference to drawings.  
         [0033]      FIGS. 1 through 4  show a first embodiment of the present invention.  
         [0034]     As shown in  FIG. 1 , a fuse connection box  10  has a function of connecting a fuse  30  and a pair of electric wires W (W 1 , W 2 ) to each other. An opening at one end of a housing  11  is formed as a terminal fitting insertion opening  11   a  for a pair of terminal fittings (hereinafter referred to as terminals) crimped to ends of the electric wires W 1 , W 2  respectively. Another opening is formed at the other end of the housing  11  as a fuse insertion opening  11   b.    
         [0035]     Inside the housing  11 , a terminal accommodation space at the side of the terminal fitting insertion opening  11   a  is partitioned with a pair of partitioning walls  13 ,  14  to form a pair of terminal accommodation chambers  20 ,  21 . Inside the housing  11 , a space at the side of the fuse insertion opening  11   b  is formed as a fuse accommodation space  22  communicating with a pair of the terminal accommodation chambers  20 ,  21 .  
         [0036]     As shown in  FIG. 2 , two slits  23  are formed in the partitioning walls  13  and  14  from approximately a vertically central position thereof toward the fuse insertion opening  11   b  to form elastically deformable lances  15 ,  16 . Locking claws  15   a,    16   a  are projected from the lances  15 ,  16  respectively toward the terminal accommodation chambers  20 ,  21 . The partitioning walls  13 ,  14  are connected to each other with an “H”-shaped reinforcing connection frame  17  in the vicinity of proximal positions (proximal position of slit  23 ) of the lances  15 ,  16 . Each of the lances  15 ,  16  is capable of elastically deforming, with a free end disposed at the side where the locking claws  15   a,    16   a  are formed and with a fixed end disposed at the proximal side of the slit  23 .  
         [0037]     A penetration space  19  communicating with the terminal fitting insertion opening  11   a  is formed between the partitioning walls  13  and  14 . The reinforcing connection frame  17  shields the penetration space  19 , thereby functioning as a waterproof wall.  
         [0038]     A flexing restraining rib  18 , sectionally mountain-shaped, projects from an upper surface of the central portion of the reinforcing connection frame  17 . The flexing restraining rib  18  is lower than the upper end of the locking claws  15   a,    16   a  of the lances  15 ,  16  disposed at both sides of the flexing restraining rib  18 . The gap between the lance  15  and an inclined surface  18   a  of the flexing restraining rib  18  and the gap between the lance  16  and an inclined surface  18   b  are gradually increased toward the free ends of the lances  15 ,  16 .  
         [0039]     Female terminals  25 A,  25 B crimped to the ends of the electric wires W 1 , W 2 , respectively, are inserted into a pair of the terminal accommodation chambers  20 ,  21 , which are respectively surrounded by a peripheral wall of the housing  11  and the partitioning walls  13 ,  14 , from the terminal fitting insertion opening  11   a.  The locking claws  15   a,    16   a  of the lances  15 ,  16  are locked to locking portions  25 A- 1 ,  25 B- 1 , which are respectively formed on the female terminals  25 A,  25 B. Thereby the female terminals  25 A,  25 B are fixedly held inside the terminal accommodation chambers  20 ,  21 , respectively.  
         [0040]     The dimension of the fuse accommodation space  22  disposed at the distal side of the lances  15 ,  16  is set so that the fuse  30  can be removably inserted thereinto. The fuse  30  is similar to that of the JP-A-2004-158256. More specifically, the fuse  30  is approximately rectangular and has a small height (so-called low fuse). An input terminal  32  and an output terminal  33  parallel therewith are exposed from cut-outs  31   a,    31   b  disposed at left and right sides of the fuse body  31  made of resin. A stepped portion  22   a  to which an upper end surface of the fuse body  31  is locked may be formed on an inner surface of the upper end of the fuse accommodation space  22 .  
         [0041]     In the fuse connection box  10 , as shown in  FIG. 3 , the female terminals  25 A,  25 B are inserted into the terminal accommodation chambers  20 ,  21 , respectively and locked to the lances  15 ,  16 , respectively. When the fuse  30  is inserted into the fuse accommodation space  22  from the fuse insertion opening  11   b  in this state, the female terminals  25 A and  25 B crimped to the ends of the electric wires W 1 , W 2 , respectively, are contacted with the input terminal  32  and the output terminal  33 , respectively, of the fuse  30 . Thereby the fuse  30  and the electric wires are electrically connected with each other.  
         [0042]     When it is necessary to remove the female terminals  25 A,  25 B from the fuse connection box  10 , the fuse  30  is pulled out of the fuse insertion opening  11   b.    
         [0043]     Thereafter, as shown in  FIG. 4 , a rod-shaped unlocking jig  50  is inserted into the fuse accommodation space  22  from the fuse insertion opening  11   b  to pull out the terminal  25 A from the terminal fitting insertion opening  11   a  by unlocking the locking portion  25 A- 1  of the terminal  25 A and the lance  15  from each other. Similarly the unlocking jig  50  is inserted into the fuse accommodation space  22  from the fuse insertion opening  11   b  to pull out the terminal  25 B from the terminal fitting insertion opening  11   a  by unlocking the locking portion  25 B- 1  of the terminal  25 B and the lance  16  from each other.  
         [0044]     In unlocking the locking portions of the terminals and the lances from each other with the unlocking jig  50 , the lances  15 ,  16  are elastically deformed toward a side opposite to the locking side. When the lance  15  is elastically deformed and contacts one inclined surface  18   a  of the flexing restraining rib  18 , the lance  15  is prevented from elastically deforming beyond the contact position. Thus it is possible to prevent the lance  15  from excessively elastically deforming.  
         [0045]     Similarly, when the lance  16  is elastically deformed and contacts the other inclined surface  18   b  of the flexing restraining rib  18 , the lance  16  is prevented from elastically deforming beyond the contact position. Thus it is possible to prevent the lance  16  from excessively elastically deforming.  
         [0046]     The flexing restraining rib  18  is preferably mountain-shaped, to allow the elastically deformed lances  15 ,  16  to make a surface contact with the inclined surfaces  18   a,    18   b  respectively. Therefore a stress caused by the elastic deformation does not concentrate on any one point of each of the lances  15 ,  16 . Therefore, the lances  15 ,  16  may be prevented from being damaged or broken.  
         [0047]     The partitioning walls  13 ,  14  having the lances  15 ,  16  respectively formed at the upper ends thereof may be connected to each other with the reinforcing connection frame  17  at the proximal portions of the lances  15 ,  16 . Thus, the partitioning walls  13 ,  14  are prevented from elastically deforming. Therefore, when the terminals  25 A,  25 B are taken out of the fuse connection box  10  with the unlocking jig  50 , it is possible to prevent the lances  15 ,  16  from being damaged and the partitioning walls  13 ,  14  from being deformed and/or damaged.  
         [0048]     In the fuse connection box  10  of an embodiment of the present invention, although an opening is formed at the lower end of the space between the partitioning walls  13 ,  14 , the reinforcing connection frame  17  connecting the partitioning walls  13 ,  14  to each other is provided in the space between the partitioning walls  13 ,  14 . Thus the reinforcing connection frame  17  serves as a waterproof wall. Therefore it is possible to reliably prevent water which has penetrated into the fuse connection box  10  from the opening from entering the portion of the fuse connection box where there is contact between the terminal of the fuse  30  and the female terminals  25 A,  25 B.  
         [0049]     Further, in the exemplary embodiments of the invention, because the height of the fuse to be connected with the terminals is smaller than the height of a fuse where the terminals extend from the fuse body, the fuse connection box  10  may be more compact and lightweight. Therefore, the fuse connection box  10  may be able to be manufactured at a reduced cost.  
         [0050]      FIG. 5  shows a second embodiment. In the second embodiment, a mini-fuse  30 ′, different from the first embodiment, is mounted inside the fuse connection box. In the second embodiment, the lances  15 ,  16  formed at the upper ends of the partitioning walls  13 ,  14 , respectively, are disposed nearer to the fuse insertion opening  11   b  than the lances  15 ,  16  of the first embodiment. Portions of the partitioning walls  13  and  14  in the vicinity of the proximal portions of the lances  15 ,  16  are connected to each other with the reinforcing connection frame  17 . A rod-shaped flexing restraining rib  18 ′ is projected upward from a central portion of the reinforcing connection frame  17 , with a gap formed between the flexing restraining rib  18 ′ and the lances  15 ,  16  disposed at both sides thereof.  
         [0051]     Similarly to the first embodiment, in the second embodiment, in taking out the female terminals  25 A,  25 B from the fuse connection box by unlocking the female terminals  25 A,  25 B from the lances  15 ,  16 , respectively, the unlocking jig  50  is inserted into the locking portions of the female terminals  25 A,  25 B to elastically deform the lances  15 ,  16 . Thereby the female terminals  25 A,  25 B are unlocked from the lances  15 ,  16 , respectively.  
         [0052]     When the lances  15 ,  16  flex excessively, they contact the rod-shaped flexing restraining rib  18 ′. Therefore, it is possible to prevent the lances  15 ,  16  from flexing excessively and thereby reduce the possibility of breaking them.  
         [0053]     Similarly to the first embodiment, in the second embodiment, the reinforcing connection frame  17  may function as a waterproof wall and enhance the waterproof performance of the fuse connection box.  
         [0054]     Although the invention has been described with reference to specific embodiments, those embodiments should be viewed as illustrative and not limiting. Various modifications, substitutions and improvements are possible within the spirit and scope of the invention.