Patent Publication Number: US-9418813-B2

Title: Fuse assembly

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application is based on Japanese Patent Application No. 2012-257764 filed on Nov. 26, 2012, the disclosure of which is incorporated herein by reference. 
     FIELD OF TECHNOLOGY 
     The present disclosure relates to a fuse assembly and more particularly to a structure for a fuse mounting portion of an electric connector box to which a fuse sub-assembly is mounted. 
     BACKGROUND 
     A fuse assembly is known in the art, for example, as disclosed in Japanese Patent No. 4,238,783, which discloses a structure for a fuse mounting portion of an electric connector box, to which fuse sub-assemblies are mounted. According to the structure for the fuse mounting portion of the above prior art, it is possible to mount two kinds of fuse sub-assemblies to the electric connector box, wherein outer dimensions of the fuse sub-assemblies in a fuse-insertion direction (more exactly, a length in a height direction of the fuse sub-assembly) are different from each other. A pair of ribs is provided in a cavity of a housing for the electric connector box in a width direction of the cavity, wherein each of the ribs is projecting into an inside of the cavity. An upper end surface of each rib, namely an end surface of the rib on a side to an opening end of the cavity, is inclined with respect to the fuse-insertion direction. 
     When the fuse sub-assembly is inserted into the cavity, a stepped portion of the fuse sub-assembly is brought into contact with the inclined surfaces of the ribs, so that the fuse sub-assembly is positioned in the fuse mounting portion. 
     The housing of the electric connector box of the above prior art is generally made of resin. When thermal shock is applied to the housing made of resin, the fuse mounting portion is thermally expanded or contracted. Then, a relative positional relationship between the ribs and female terminals (made of, for example, copper alloy) provided in the cavity may be changed. For example, when the cavity is thermally expanded, the fuse sub-assembly is pushed in the width direction of the cavity (perpendicular to the fuse-insertion direction) by the inclined surface of the rib. 
     As a result, the fuse sub-assembly is relatively moved in the cavity whenever the thermal expansion and contraction are repeated in the cavity. In other words, sliding movement of a male terminal with respect to the female terminal is repeatedly carried out in the cavity. As a result, contact failure is likely to occur between the male terminal and female terminal provided in the cavity due to abrasion powder of the terminals and/or decrease of contact pressure between the terminals. When the contact failure occurs in the fuse sub-assembly, voltage drop may occur at the terminals of the contact failure and operation of an electric or electronic devices connected to the fuse sub-assembly may be adversely affected due to such voltage drop. 
     SUMMARY OF THE DISCLOSURE 
     The present disclosure is made in view of the above problem. It is an object of the present disclosure to provide a structure of a fuse mounting portion made of resin, according to which contact failure of a fuse sub-assembly to be caused by thermal expansion and contraction can be avoided. 
     According to a feature of the present disclosure, a fuse sub-assembly having a pair of male terminals is inserted into a fuse mounting portion in a fuse-insertion direction. The fuse mounting portion has a cavity portion made of resin and has an opening end, through which the fuse sub-assembly is mounted to the cavity portion. The fuse mounting portion has a pair of female terminals, which is electrically connected to the respective male terminals when the fuse sub-assembly is inserted into the cavity portion. The female terminals hold the fuse sub-assembly in the cavity portion. 
     The cavity portion has a stopper portion, with which the fuse sub-assembly is brought into contact in a fuse-mounted condition. The cavity portion further has a pair of projecting portions projecting into an inside of the cavity portion. The projecting portions are arranged in a width direction of the cavity portion. 
     Guide surfaces are formed at each projecting portion for guiding the male terminals toward the female terminals when the fuse sub-assembly is inserted into the cavity portion. A distance between the pair of the guide surfaces in the width direction becomes larger in the fuse-insertion direction toward the opening end of the cavity portion. 
     A gap is formed between the fuse sub-assembly and the guide surfaces in the fuse-mounted condition, in which the fuse sub-assembly is inserted into the cavity portion until the fuse sub-assembly is brought into contact with the stopper portion. 
     According to the above structure, the fuse sub-assembly mounted to the fuse mounting portion hardly moves in the cavity portion, even when the cavity portion is thermally expanded and contracted due to thermal shock. As a result, it is possible to prevent contact failure of the fuse sub-assembly. 
     According to another feature of the present disclosure, multiple fuse mounting portions are integrally formed in a housing of the fuse assembly and arranged with one another in the width direction, in which the projecting portions of each pair are respectively arranged in a line. 
     When the multiple fuse mounting portions are arranged in the line, an outside dimension of the housing made of resin becomes larger in the width direction of the cavity portion. As a result, an amount of the thermal expansion and the thermal contraction caused by the thermal shock in the cavity portion becomes correspondingly larger in the width direction. Then, the guide surfaces formed at the projecting portions are more likely to move in the width direction, in which the fuse sub-assembly may be moved. Accordingly, the effect of the present disclosure for preventing the contact failure caused by the thermal expansion and contraction can be more remarkably produced in such fuse assembly having the multiple fuse mounting portions. 
     According to a further feature of the present disclosure, the gap is made to be larger in the fuse mounting portion, which is more separated from an intermediate fuse mounting portion in the width direction. 
     According to such a structure, the gap between the fuse sub-assembly and the guide surfaces can be designed by a proper value so as to prevent the contact failure of the fuse sub-assembly, which may be caused by thermal expansion and/or thermal contraction of the cavity portion  16 . In addition, since it is not necessary to make the gap larger than needs at a center of the housing or at the intermediate fuse mounting portion, it is possible to make an outside dimension of the housing at a proper value. For example, when compared with a case in which the gap is made equal to one another among the fuse mounting portions, the outside dimension of the housing can be made smaller in the above structure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other objects, features and advantages of the present disclosure will become more apparent from the following detailed description made with reference to the accompanying drawings. In the drawings: 
         FIG. 1A  is a schematic perspective view showing an electric connector box according to an embodiment of the present disclosure; 
         FIG. 1B  is a schematically enlarged perspective view showing a part of fuse mounting portions of the electric connector box of  FIG. 1A ; 
         FIG. 2  is a schematic enlarged view of the fuse mounting portion indicated by II in  FIG. 1A , when viewed in a fuse-insertion direction X; 
         FIG. 3  is a schematic cross sectional view taken along a line III-III in  FIG. 2 ; 
         FIG. 4  is a schematic cross sectional view taken along a line IV-IV in  FIG. 3 ; 
         FIG. 5  is a schematic perspective view showing a terminal member, in which multiple female terminals are formed; 
         FIG. 6  is a schematic front view showing a fuse sub-assembly, which is mounted to the fuse mounting portion of  FIG. 1A ; 
         FIG. 7A  is a schematic side view showing the fuse sub-assembly, when viewed in a direction VIIA in  FIG. 6 ; 
         FIG. 7B  is a schematic cross sectional view taken along a line VIIB-VIIB in  FIG. 6 ; 
         FIG. 7C  is a schematic cross sectional view taken along a line VIIC-VIIC in  FIG. 6 ; 
         FIG. 7D  is a schematic cross sectional view taken along a line VIID-VIID in  FIG. 6 ; 
         FIG. 8A  is a schematic view showing the fuse sub-assembly of  FIG. 6 , which is mounted to the fuse mounting portion of  FIG. 3 ; 
         FIG. 8B  is a schematic view showing the fuse sub-assembly of  FIG. 6 , which is mounted to the fuse mounting portion of  FIG. 3 , in which the gap between the between the fuse sub-assembly and the guide surfaces is smaller than a similar gap in  FIG. 8A ; 
         FIG. 8C  is a schematic view showing the fuse sub-assembly of  FIG. 6 , which is mounted to the fuse mounting portion of  FIG. 3 , in which the guide surfaces are convex; 
         FIG. 8D  is a schematic view showing the fuse sub-assembly of  FIG. 6 , which is mounted to the fuse mounting portion of  FIG. 3 , in which the guide surfaces are concave; 
         FIG. 9  is a schematic view showing the fuse sub-assembly, a fuse main body of which is brought into contact with a guide surface of the fuse mounting portion; 
         FIG. 10  is a schematic view showing a tongue-shaped female terminal; and 
         FIG. 11  is a schematic showing a faston female terminal. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     The present disclosure will be explained hereinafter byway of an embodiment with reference to the drawings. 
     As shown in  FIG. 1A , an electric connector box  10  has multiple fuse mounting portions  14 , to each of which a fuse sub-assembly  12  (shown in  FIGS. 6 and 7A to 7D ) is mounted. The electric connector box  10  is, for example, a fuse box for a vehicle, or a relay box having the multiple fuse mounting portions  14  and electrical parts and/or components, such as, relays. The electric connector box  10  is mounted, for example, in an engine room of the vehicle. A housing  15 , which forms a part of a casing of the electric connector box  10 , is made of resin, for example, PBT resin, PP resin or the like. 
     A structure of the fuse mounting portion  14  of the electric connector box  10  will be explained. Although the electric connector box  10  has multiple fuse mounting portions  14  arranged in a line, each of the fuse mounting portions  14  has the same structure to one another. In  FIG. 1A  (as well as in the other drawings), an arrow X is a fuse-insertion direction in which the fuse sub-assembly  12  is inserted into the corresponding fuse mounting portion  14 . An arrow DR 1  is referred to as a first direction or a height direction of the fuse sub-assembly  12 , which is parallel to the fuse-insertion direction X. An arrow DR 2  is referred to as a second direction, in which the multiple fuse mounting portions  14  are arranged in a row. The second direction DR 2  corresponds to a thickness direction or a width direction of the fuse sub-assembly  12 . An arrow DR 3  is referred to as a third direction or a longitudinal direction of the fuse sub-assembly  12 , which is perpendicular to the first and second directions DR 1  and DR 2 . The second direction DR 2  is perpendicular to the first direction DR 1 . 
     The fuse mounting portion  14  is symmetrical with respect to a center point “O” in  FIG. 2 . Therefore, a structure of an upper-side portion of the fuse mounting portion  14  in  FIG. 2  is identical to that of a lower-side portion thereof in  FIG. 2 . 
     As shown in  FIG. 1B  and  FIGS. 2 to 4 , each of the fuse mounting portions  14  is composed of a cavity portion  16  and a pair of female terminals  18 , which is indicated by two-dot-chain lines. The cavity portion  16  is formed in a part of the housing  15 . A fuse accommodating hole  20  is formed in the cavity portion  16 . One end of the fuse accommodating hole  20  (an upper end thereof in FIGS.  3  and  4 ) is an opening end  20   b , while the other end of the fuse accommodating hole  20  (that is, a lower end thereof in  FIG. 4 ) is closed by a bottom wall  20   a . A cross-sectional shape of the fuse accommodating hole  20  on a plane perpendicular to the fuse-insertion direction X, that is, a plane perpendicular to the first direction DR 1  is almost a rectangular (as seen from  FIG. 2 ). The bottom wall  20   a  of the fuse accommodating hole  20 , namely, the bottom wall  20   a  of the cavity portion  16  extends in the longitudinal direction of the fuse sub-assembly  12 , which corresponds to the third direction DR 3 . The fuse sub-assembly  12  is inserted into the fuse accommodating hole  20  from the upper end (the opening end  20   b ) of the fuse accommodating hole  20  (that is, the upper end  20   b  of the cavity portion  16 ). 
     A pair of through-holes  20   e  is formed in the bottom wall  20   a  of the fuse accommodating hole  20 . Each of the female terminals  18  is inserted from the outside of the cavity portion  16  into the cavity portion  16  through the corresponding through-hole  20   e . Each of the through-holes  20   e  is formed at an almost longitudinal end of the bottom wall  20   a  in the third direction DR 3  (as seen from  FIG. 2 or 4 ). 
     In the cavity portion  16 , a stopper portion  22  is formed in the bottom wall  20   a  ( FIG. 4 ). In addition, as shown in  FIG. 1B  and  FIG. 3 , a first pair of projecting portions  24   a   1  and  24   b   1  is formed in the cavity portion  16  (in the upper-side portion in  FIG. 2 ), wherein each of the projecting portions  24   a   1  and  24   b   1  is formed at each corner of the rectangular-shaped fuse accommodating hole  20 . The first pair of the projecting portions  24   a   1  and  24   b   1  is arranged in the second direction DR 2 . In a similar manner, a second pair of projecting portions  24   a   2  and  24   b   2  is formed in the cavity portion  16  (in the lower-side portion in  FIG. 2 ). Each of the projecting portions  24   a   2  and  24   b   2  is formed at each of the other corners of the fuse accommodating hole  20  and arranged in the second direction DR 2 . The projecting portions  24   a   1  and  24   b   1  as well as  24   a   2  and  24   b   2  are collectively referred to as the projecting portions  24 . 
     The stopper portion  22  as well as the projecting portions  24  form a part of the housing  15  made of the resin. The stopper portion  22  is projected in the first direction DR 1 , that is, in a direction to the cavity portion  16  from a center of the bottom wall  20   a  of the fuse accommodating hole  20 . As shown in  FIG. 2 , the stopper portion  22  is formed between the pair of the through-holes  20   e  formed in the bottom wall  20   a , that is, at an intermediate position in the third direction DR 3 . A fuse contacting surface  22   a  is so formed on a top surface of the stopper portion  22  as to be perpendicular to the first direction DR 1 . 
     The fuse contacting surface  22   a  is brought into contact with the fuse sub-assembly  12  in the first direction DR 1 , when the fuse sub-assembly  12  is inserted into the fuse accommodating hole  20 , namely when the fuse sub-assembly  12  is mounted to the fuse mounting portion  14 . In other words, the fuse contacting surface  22   a  is in contact with the fuse sub-assembly  12  in a fuse-mounted condition. 
     Each of the projecting portions  24  ( 24   a   1 ,  24   b   1 ,  24   a   2 ,  24   b   2 ) is projected into the cavity portion  16 . Since each of the projecting portions  24  is formed at each corner of the cavity portion  16 , at which side walls  20   c  and  20   d  of the fuse accommodating hole  20  intersect with each other, each of the projecting portions  24  is projected into the cavity portion  16  from the side walls  20   c  and  20   d  of the fuse accommodating hole  20 . The first pair of the projecting portions  24  ( 24   a   1  and  24   b   1 ) is formed at a longitudinal end of the fuse accommodating hole  20  in the third direction DR 3  (in the upper-side portion in  FIG. 2 ), while the second pair of the projecting portions  24  ( 24   a   2  and  24   b   2 ) is formed at the other longitudinal end of the fuse accommodating hole  20  in the third direction DR 3  (in the lower-side portion in  FIG. 2 ). As above, two pairs of the projecting portions  24  are formed in the cavity portion  16  so as to oppose to each other in the third direction DR 3 . 
     The projecting portions  24  ( 24   a   1  and  24   b   1 , or  24   a   2  and  24   b   2 ) of each pair are arranged in a thickness direction of a male terminal  60  ( FIGS. 6 and 7A to 7D ), that is, in the second direction DR 2 , so as to sandwich the male terminal  60  in the fuse-mounted condition, as shown in  FIG. 8A . 
     Guide surfaces  26   a   1 ,  26   b   1 ,  26   a   2  and  26   b   2  are formed at each projecting portion  24  ( 24   a   1 ,  24   b   1 ,  24   a   2  and  24   b   2 ) in order to smoothly guide the male terminals  60  of the fuse sub-assembly  12  into the fuse accommodating hole  20  (namely, into the cavity portion  16 ), so that each of the male terminals  60  is inserted into the respective female terminals  18  when the fuse sub-assembly  12  is mounted to the fuse mounting portion  14 . The guide surfaces  26   a   1 ,  26   b   1 ,  26   a   2  and  26   b   2  are collectively referred to guide surfaces  26 . More in detail, each of the guide surfaces  26  is formed at an upper end surface of each projecting portion  24 , wherein the upper end surface is a surface of the projecting portion  24  on a side closer to the opening end  20   b  of the fuse accommodating hole  20  in the first direction DR 1 . As shown in  FIGS. 3 and 4 , each of the guide surfaces  26  ( 26   a   1  and  26   b   1 ) is formed at a position between the opening end  20   b  of the fuse accommodating hole  20  and the female terminals  18  in the first direction DR 1 . 
     Each of the guide surfaces  26   a   1  and  26   b   1  is tapered in the first direction DR 1 . More in detail, each of the guide surfaces  26   a   1  and  26   b   1  is formed with an inclined surface (a tapered surface), which extends in parallel to the third direction DR 3  and is inclined with respect to the first direction DR 1 , so that the male terminals  60  of the fuse sub-assembly  12  can be smoothly guided to the female terminals  18 . As shown in  FIG. 1B  or  FIG. 3 , the guide surfaces  26   a   1  and  26   b   1  of the first pair of the projecting portions  24   a   1  and  24   b   1  are opposing to each other in the second direction DR 2 . A distance between the opposing guide surfaces  26   a   1  and  26   b   1  in the second direction DR 2  becomes larger in the first direction DR 1  toward the opening end  20   b  of the fuse accommodating hole  20 . Each of the guide surfaces  26   a   2  and  26   b   2  of the second pair is likewise tapered in the first direction DR 1  in the same manner to the guide surfaces  26   a   1  and  26   b   1  of the first pair of the projecting portions  24   a   1  and  24   b   1 . 
     As shown in  FIG. 1B  and  FIGS. 2 and 3 , a length of the guide surface  26   a   1  in the third direction DR 3  (in the longitudinal direction) is made to be larger than that of the guide surface  26   b   1 . In other words, a part the guide surface  26   a   1  extends in the third direction DR 3  to form a roof-like portion. The roof-like portion of the guide surface  26   a   1  overlaps with the female terminal  18  in the first direction DR 1  (in the height direction), while the guide surface  26   b   1  has no such a portion overlapping the female terminal  18  in the height direction DR 1 . 
     As shown in  FIGS. 3 and 5 , each of the female terminals  18  is formed in a tuning-fork shape having a pair of forked ends  40  and a press-insert gap  40   a  between the forked ends  40 . When the fuse sub-assembly  12  is inserted into the fuse accommodating hole  20 , a forward end of the male terminal  60  of the fuse sub-assembly  12  is brought into contact with the guide surfaces  26 . Then, each of the forward ends of the male terminals  60  is guided along the guide surfaces  26  as the fuse sub-assembly  12  is inserted in the fuse insertion direction X (the first direction DR 1 ), so that each of the forward ends is moved toward the press-insert gap  40   a  of each female terminal  18 . 
     The female terminal  18  is made of copper alloy, which is generally used as material for terminals. As shown in  FIG. 4 , the female terminals  18  of one pair are arranged in the third direction DR 3 . Each of the forked ends  40  forms a press-insert terminal portion  40  opposing to each other in the second direction DR 2 . Each of the female terminals  18  is inserted through the through-hole  20   e  and fixed to the housing  15 . For example, one of the female terminals  18  of each pair in the fuse mounting portion  14  is insert-molded with the housing  15 . The other female terminal  18  of the pair in the fuse mounting portion  14  is integrally formed with the terminal member forming a bus bar  18   a  ( FIG. 5 ) but as an independent component from the housing  15 . Then, the female terminals  18  of the bus bar  18   a  are attached to the housing  15 . 
     As shown in  FIGS. 3 and 4 , the press-insert terminal portions  40  of the female terminal  18  are projected in the first direction DR 1  into the fuse accommodating hole  20  from the bottom wall  20   a  toward the opening end  20   b . As already explained above, each of the female terminals  18  is inserted through the through-hole  20   e  formed in the bottom wall  20   a  and protruded into the fuse accommodating hole  20 , so that the press-insert gap  40   a  of the female terminal  18  is arranged in the fuse accommodating hole  20  and directed toward the opening end  20   b.    
     When the male terminal  60  of the fuse sub-assembly  12  is inserted into the press-insert gap  40   a  of the female terminal  18  in the fuse insertion direction X, the male terminal  60  and the female terminal  18  are electrically connected to each other. At the same time, the female terminal  18  physically holds the male terminal  60  inserted into the press-insert gap  40   a . In other words, the pair of the female terminals  18  holds the fuse sub-assembly  12  in the fuse accommodating hole  20  (that is, in the cavity portion  16 ). 
     As shown in  FIG. 5 , one of the female terminals  18  of each female-terminal pair is connected to another one of the female terminals  18  of the other female-terminal pair of the neighboring fuse mounting portion  14 , so that each one of the respective pairs of the female terminals  18  provided in each fuse mounting portion  14  is aligned in a straight line in the second direction DR 2 . In other words, each one of the female terminals  18  of the respective female-terminal pairs provided in the respective fuse mounting portions  14  is connected to the common terminal member, to form the bus bar  18   a  extending in the second direction DR 2 . 
     The fuse sub-assembly  12  will be explained with reference to  FIGS. 6 and 7A to 7D . The fuse sub-assembly  12  is a blade-type fuse, which is generally used for the vehicle. The fuse sub-assembly  12  has a pair of the male terminals  60  and a fuse main body  62  integrally connected to the male terminals  60 . 
     Each of the male terminals  60  is made of metal and formed in a plate shape. In the fuse-mounted condition, a thickness direction of the male terminals  60  corresponds to the second direction DR 2  and the male terminals  60  of each male-terminal pair are aligned in the third direction DR 3  (in the longitudinal direction of the fuse sub-assembly  12 ). 
     The fuse main body  62  is made of resin, for example, polyamide resin. The fuse main body  62  includes inside thereof a fuse element (not shown), which is provided between the male terminals  60  of the pair and respectively connected to the male terminals  60 . As shown in  FIG. 6 , a base body portion  62   b  of the fuse main body  62 , that is an upper portion in  FIG. 6 , extends in the third direction DR 3  along a whole length of the fuse sub-assembly  12 . An intermediate portion  62   c  of the fuse main body  62  extends from the base body portion  62   b  in the fuse insertion direction X in an area between the pair of the male terminals  60  to a point close to a forward end of each male terminal  60 . 
     A pair of shoulder portions  63  and  64  is integrally formed with the base body portion  62   b  at both longitudinal sides of the intermediate portion  62   c  in the third direction DR 3 . In other words, the shoulder portion  63  is formed at a longitudinal end of the base body portion  62   b  (in a left-hand side in  FIG. 6 ), while the shoulder portion  64  is formed at another longitudinal end of the base body portion  62   b  (in a right-hand side in  FIG. 6 ). 
     A thickness of the base body portion  62   b  is larger than that of the male terminals  60  in the second direction DR 2 . A contacting portion  62   a  is formed at a lower end of the intermediate portion  62   c . The contacting portion  62   a  is brought into contact with the fuse contacting surface  22   a  of the stopper portion  22  in the fuse-mounted condition. The contacting portion  62   a  is formed by a flat surface perpendicular to the fuse insertion direction X (the first direction DR 1 ). 
     The fuse sub-assembly  12  is inserted into the fuse accommodating hole  20  of the fuse mounting portion  14  so that the fuse sub-assembly  12  is mounted to the fuse mounting portion  14 . In the fuse-mounted condition, each of the male terminals  60  is interposed between the pair of the forked ends  40  of the respective female terminals  18 , so that the fuse sub-assembly  12  is firmly supported in the fuse mounting portion  14 . The contacting portion  62   a  of the fuse main body  62  is in contact with the fuse contacting surface  22   a  of the stopper portion  22  in the first direction DR 1 , so that the fuse sub-assembly  12  is positioned in the fuse mounting portion  14  in the first direction DR 1 .  FIG. 8A  schematically shows, in a cross section of the second direction DR 2 , the fuse sub-assembly  12  mounted to the fuse mounting portion  14  in the fuse-mounted condition. 
     As shown in  FIG. 8A , the fuse sub-assembly  12  is inserted into the fuse accommodating hole  20  (into the cavity portion  16 ) of the fuse mounting portion  14  until the fuse sub-assembly  12  is brought into contact with the stopper portion  22 . A gap is formed between the fuse sub-assembly  12  and the fuse mounting portion  14  in the first and second directions DR 1  and DR 2 . More exactly, a first gap CLS-a is formed between a first lower edge P 1   a  of a left-hand side  63   a  of the shoulder portion  63  and the guide surface  26   a   1  of the first pair. A second gap CLS-b is likewise formed between a second lower edge P 1   b  of a right-hand side  63   b  of the shoulder portion  63  and the guide surface  26   b   1  of the first pair. 
     The first lower edge P 1   a  corresponds to a most neighboring point of the fuse sub-assembly  12  to the guide surface  26   a   1 , at which the first lower edge P 1   a  is closest to the guide surface  26   a   1  in the fuse-mounted condition. In a similar manner, the second lower edge P 1   b  corresponds to a most neighboring point of the fuse sub-assembly  12  to the guide surface  26   b   1 , at which the second lower edge P 1   b  is closest to the guide surface  26   b   1  in the fuse-mounted condition. 
     As above, even in the fuse-mounted condition, in which a part of the fuse main body  62  (the first and/or second lower edges P 1   a  and/or P 1   b ) is located at the position closest to the guide surface  26   a   1  and/or  26   b   1 , the gaps CLS-a and CLS-b are formed between the first and second lower edges P 1   a  and P 1   b  and the guide surfaces  26   a   1  and  26   b   1 . In other words, any part of the fuse main body  62  is not brought into contact with the guide surfaces  26   a   1  and  26   b   1 , when the fuse sub-assembly  12  is inserted into the fuse accommodating hole  20 . 
     The first gap CLS-a and the second gap CLS-b are collectively referred to as the gap(s) CLS. A value of the gap CLS is determined based on a positional relationship between the fuse contacting surface  22   a  of the stopper portion  22  and the guide surfaces  26   a   1  and  26   b   1  as well as a positional relationship between the contacting portion  62   a  of the fuse main body  62  and the most neighboring points P 1   a  and P 1   b  of the fuse sub-assembly  12  to the guide surfaces  26   a   1  and  26   b   1  in the fuse-mounted condition. Since the contacting portion  62   a  is in contact with the fuse contacting surface  22   a  in the fuse-mounted condition, the fuse sub-assembly  12  is not allowed to further move in the fuse insertion direction X from the position shown in  FIG. 8A . 
     Each of the gaps CLS-a and CLS-b, shown in  FIG. 8A , formed between the fuse sub-assembly  12  and the respective guide surfaces  26   a   1  and  26   b   1  may be identical to, or different from, each other. 
     If the fuse main body  62  is in contact with the guide surface  26   b   1  at a contacting point Al, as shown in  FIG. 9 , the fuse sub-assembly  12  may swing in the second direction DR 2  as indicated by an arrow AR 2  when the cavity portion  16  thermally expands or contracts in a direction of an arrow AR 1 . The swinging movement of the fuse sub-assembly  12  continues, so long as the cavity portion  16  repeatedly and thermally expands and contracts. Then, the male terminal  60  repeatedly slides on the female terminal  18  at terminal contacting points CON. 
     According to the present embodiment, however, as shown in  FIG. 8A , the gap CLS is formed between the fuse sub-assembly  12  and the guide surfaces  26  ( 26   a   1 ,  26   b   1 ,  26   a   2 ,  26   b   2 ) formed in the cavity portion  16  in the fuse-mounted condition, in which the fuse sub-assembly  12  is inserted into the fuse accommodating hole  20  until the fuse sub-assembly  12  is brought into contact with the stopper portion  22 . Therefore, the fuse sub-assembly  12  is prevented from swinging due to the thermal expansion and/or thermal contraction of the cavity portion  16  caused by thermal impulses. As a result, it is possible to avoid contact failure of the fuse sub-assembly  12 , namely the contact failure between the male terminals  60  and the female terminals  18 . 
     In  FIG. 9 , the fuse main body  62  is in contact with the guide surface  26   b   1  but not in contact with the other guide surface  26   a   1 . However, even when the fuse main body  62  is in contact with both of the guide surfaces  26   a   1  and  26   b   1 , the swinging movement of the fuse sub-assembly  12  may occur in the second direction DR 2  like the movement indicated by the arrow AR 2 . This is because an amount of displacement of the guide surfaces  26   a   1  and  26   b   1  (as well as  26   a   2  and  26   b   2 ) caused by the thermal fluctuation is different from an amount of displacement of the female terminal  18 . 
     In  FIG. 8A  (in the fuse-mounted condition), the gap (CLS-a, CLS-b) is formed between the fuse sub-assembly  12  and all area of the guide surfaces  26   a   1  and  26   b   1 . It is sufficient for the present embodiment that the gap is formed at least at a normal temperature, for example, at 20° C. A value of the gap CLS is so designed as to avoid the contact failure of the fuse sub-assembly  12  between the male and the female terminals  60  and  18 , even when the electrical connector box  10  is subjected to high or low temperature in its actual environment of usage. 
     According to the present embodiment, multiple fuse mounting portions  14  are aligned in a straight line, in which the pairs of the projecting portions  24  ( 24   a   1 ,  24   b   1  or  24   a   2 ,  24   b   2 ) are arranged, as shown in  FIG. 1A . As a result, an outer shape of the housing  15  made of the resin, in which the multiple cavity portions  16  are formed, becomes larger in the second direction DR 2  in which the multiple fuse mounting portions  14  are formed. 
     Therefore, an amount of thermal expansion and/or thermal contraction of the cavity portions  16  may become correspondingly larger in the second direction DR 2 . Then, the guide surfaces  26  formed on the projecting portions  24  are likely to move in the direction, in which the fuse sub-assembly  12  is forced to swing. According to the present embodiment (having the multiple fuse mounting portions  14  in the line), the effect for preventing the contact failure of the fuse sub-assembly  12  caused by the thermal fluctuation can become more remarkable, when compared with a case having one fuse mounting portion. 
     In the fuse-mounted condition of the present embodiment, the contacting portion  62   a  of the fuse sub-assembly  12  is brought into contact with the fuse contacting surface  22   a  of the cavity portion  16  in order to position the fuse sub-assembly  12  in the fuse mounting portion  14  in the first direction DR 1 . When the cavity portion  16  as well as the fuse main body  62  is thermally expanded, the fuse sub-assembly  12  is pushed back in the opposite direction to the fuse-insertion direction X. 
     When the fuse sub-assembly  12  is once pushed back, the fuse sub-assembly  12  is held at such a pushed-back position. When the thermally expanded cavity portion  16  of the fuse main body  62  is turned back to its initial condition, a gap is generated in the first direction DR 1  between the contacting portion  62   a  and the fuse contacting surface  22   a . As a result, even when the cavity portion  16  and the fuse main body  62  thereafter repeat the thermal expansion and the thermal contraction, the male terminal  60  does not repeatedly slide on the female terminal  18  in the first direction DR 1 . The contact failure of the fuse sub-assembly  12  can be thus avoided. 
     OTHER EMBODIMENTS AND/OR MODIFICATIONS 
     The present disclosure should not be limited to the above embodiment but can be modified in various manners, for example, in the following manners. 
     (1) In the above embodiment, as shown in  FIG. 1B  and  FIGS. 2 and 3 , the part of the guide surface  26   a   1  (the roof-like portion) is so formed as to overlap with the female terminal  18  in the first direction DR 1  (in the height direction), while the other guide surface  26   b   1  does not have such a part overlapping with the female terminal  18  in the height direction DR 1 . However, the other guide surface  26   b   1  can be also so modified as to overlap with the female terminal  18  in the height direction DR 1 . 
     (2) In the above embodiment, each of the guide surfaces  26   a   1 ,  26   b   1 ,  26   a   2  and  26   b   2  is formed by the flat surface. However, the guide surface(s) can be formed by a curved surface of a concave or a convex, as shown in  FIGS. 8C and 8D , respectively. 
     (3) In the above embodiment, the fuse sub-assembly  12  is composed of so-called a low-type fuse having a small height. However, any type of fuses, such as, so-called a mini-type fuse, can be used. In the above embodiment, as shown in  FIG. 8A , the entire body of the fuse sub-assembly  12  is accommodated in the cavity portion  16  in the fuse-mounted condition. However, a part of the fuse sub-assembly may not be accommodated in the cavity portion  16 . 
     (4) In the above embodiment, each of the male terminals  60  is composed of the plate-type terminal. The male terminal  60  may not be always made of the plate-type terminal. 
     (5) In the above embodiment, the female terminal  18  of the fuse mounting portion  14  is composed of the press-insert type terminal. However, the female terminal  18  may be made of any other types, such as a tongue-shaped terminal, a faston terminal, and so on. An example of a tongue-shaped female terminal is disclosed in  FIG. 10 , while an example of a faston female terminal is shown in  FIG. 11 . 
     (6) In the above embodiment, the guide surfaces  26  are so made that the gap CLS in one fuse mounting portion  14  is made to be identical to the gap CLS in the other fuse mounting portion  14 . However, the gaps CLS may be different from the fuse mounting portion  14  to the fuse mounting portion  14 . 
     For example, the gap CLS in each fuse mounting portion  14  can be made larger in a direction from a center of the housing  15  toward an outer side thereof in the second direction DR 2  or in a direction from an intermediate fuse mounting portion  14  toward an outer-most fuse mounting portion  14  in the second direction DR 2 . In other words, the gap CLS defined in  FIG. 8A  in the fuse mounting portion  14  located at a position B 2  in  FIG. 1A  is larger than the gap CLS in the fuse mounting portion  14  located at a position B 1  (the center of the housing  15  in the second direction DR 2 ). 
     According to such a modification, the gap CLS between the fuse sub-assembly  12  and the guide surfaces  26   a   1  and  26   b   1  (as well as  26   a   2  and  26   b   2 ) can be designed by a proper value so as to prevent the contact failure of the fuse sub-assembly, which may be caused by thermal expansion and/or thermal contraction of the cavity portion  16 . 
     In addition, since it is not necessary to make the gap CLS larger than needs at the center of the housing  15  or at the intermediate fuse mounting portion  14 , it is possible to make an outside dimension of the housing  15 , namely an outside dimension of the electric connector box  10 , at a proper value. For example, when compared with a case in which the gap CLS is made equal to one another among the fuse mounting portions, the outside dimension of the housing  15  can be made smaller in the above modification. 
       FIG. 8B  is a schematic view showing the fuse sub-assembly of  FIG. 6 , which is mounted to the fuse mounting portion of  FIG. 3 , in which the gap between the between the fuse sub-assembly and the guide surfaces is smaller than a similar gap in  FIG. 8A . Therefore,  FIGS. 8A and 8B  together show that the gap can be relatively larger or relatively smaller in different embodiments. 
     As above, the present disclosure should not be limited to the above-explained embodiment but can be modified in various manners within scopes of protection in the following claims.