Abstract:
An elongated hollow housing is made of a conductive material. The housing includes an opened first end for receiving the male terminal and a second end connected to the power supply. A first contactor made of a conductive material is located in the housing. The first contactor contacts the male terminal received into the housing. A second contactor made of a conductive material is located in the housing at a position closer to the first end than the first contactor is. The second contactor contacts the male terminal when the male terminal is inserted into the housing. The second contactor is deformed to separate from the male terminal after the male terminal is separated from the first contactor when the male terminal is removed from the housing.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a high voltage terminal used for wires on a vehicle. 
     In general, solderless terminals are often used for electrically connecting devices to one another in a vehicle. 
     A typical solderless terminal shown in FIG.  4 ( a ) has a main body  40 . A receptacle  41  is provided at one end of the main body  40 . A lug  42  is provided at the other end of the main body  40 . A pair of contactors  43 ,  44  are located in the receptacle  41  to face each other. When a prong  1  of a terminal is inserted in the receptacle  41 , the contactors  43 ,  44  contact the prong  1 . The lug  42  has a U-shaped cross-section with a bottom  42   b  and sidewalls projecting from the bottom  42 . Two pairs of crimp pieces  45 ,  46  formed at the sidewalls. A wire  2  is placed in the U-shaped section. Then, the crimp pieces  45 ,  46  are bent toward the axis of the wire  2  to crimp the wire  2  to the lug  42 . As a result, the wire  2  is electrically connected to the terminal main body  40 . After the wire  2  is coupled, the main body  40  is fitted in one of sockets  51  of a female connector housing  50  shown in FIG.  5 . The connector housing  50  is made of insulating resin. A prong  1  (not shown in FIG. 5) is located in each socket  51  of the connector housing  50 . The terminal main body  40  is electrically connected to the corresponding prong  1 . 
     In recent years, vehicles have an increasing load of electric devices. To deal with the capacitance of the electric loads, some vehicles are equipped with a 42V battery instead of conventionally used 14V batteries. 
     When the prong  1  is manually pulled out of the terminal main body  40  while the terminal is energized, continuous electric arc is generated between the prong  1  and the contactors  43 ,  44 . Particularly, when the prong  1  and the terminal is connecting an electrical load to a high-voltage power supply, the arc is increased. The increased arc roughens the surfaces of the contactors  43 ,  44  and the prong  1 . The roughened surfaces increase the contact resistance between the contactors  43 ,  44  and the prong  1 . Thus, when energized, the contactors  43 ,  44  produce heat due to electrical resistance. Since the female connector housing  50  is made of insulating resin, the produced heat can damage the housing  50 . Therefore, when the terminal main body  40  connects an electric load with a high-voltage power supply, the reliability of the main body  40  can deteriorate. 
     SUMMARY OF THE INVENTION 
     Accordingly, it is an objective of the present invention to provide a solderless high voltage terminal that prevents generation of arc between contactors and a prong of a male terminal. 
     To achieve the foregoing and other objectives and in accordance with the purpose of the present invention, a high-voltage terminal for connecting a high-voltage power supply with a male terminal extending from an electric component is provided. The high-voltage terminal includes an elongated hollow housing made of a conductive material, a first contactor mad of a conductive material, and a second contactor made of a conductive material. The housing includes an opened first end for receiving the male terminal, and a second end connected to the power supply. The first contactor is located in the housing. When the male terminal is inserted into the housing, the first contactor contacts the male terminal. The second contactor is located in the housing at a position closer to the first end than the first contactor is. When the housing receives the male terminal, the second contactor contacts the male terminal and is deformed by arc generated by the contact with the male terminal. When the male terminal is removed from the housing, the second contactor is deformed to separate from the male terminal after the male terminal is separated from the first contactor. 
     Other aspects and advantages of the invention will become apparent from the following description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention, together with objects and advantages thereof, may best be understood by reference to the following description of the presently preferred embodiments together with the accompanying drawings in which: 
     FIG.  1 ( a ) is a plan view illustrating a solderless high voltage terminal according to a preferred embodiment of the present invention; 
     FIG.  1 ( b ) is a cross-sectional view taken along line  1 ( b )— 1 ( b ) of FIG.  1 ( a ); 
     FIG.  1 ( c ) is an enlarged cross-sectional view of FIG.  1 ( b ); 
     FIG. 2 is a perspective view of the terminal shown in FIG.  1 ( a ); 
     FIG.  3 ( a ) is a cross-sectional view of the terminal shown in FIG.  1 ( a ) when a prong of a male terminal is completely inserted; 
     FIG.  3 ( b ) is a cross-sectional view of the terminal shown in FIG.  1 ( a ) when a first contactor is separated from the prong; 
     FIG.  3 ( c ) is a cross-sectional view of the terminal shown in FIG.  2 ( a ) when a second contactor is separated from the prong; 
     FIG.  4 ( a ) is a cross-sectional view of a prior art solderless terminal when a prong of a male terminal is completely inserted; 
     FIG.  4 ( b ) is a cross-sectional view of the prior art solderless terminal of FIG.  4 ( a ) when the prong is completely pulled out; and 
     FIG. 5 is a perspective view showing the prior art solderless terminal of FIG.  4 ( a ) inserted in a connector housing. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     A solderless terminal according to a preferred embodiment of the present invention will now be described with reference to FIGS.  1 ( a ) to  3 ( c ). 
     A main body  10  of the solderless terminal is formed by die-cutting a conductive metal plate into a predetermined shape and then bending predetermined sections. The metal for forming the terminal main body  10  is made of copper, a copper alloy, or other metal. As shown in FIGS.  1 ( a ) and  1 ( b ), the terminal main body  10  includes a lug  12  and a receptacle  11 . The receptacle  11  has a rectangular cross-section and includes an upper wall  11   a,  a lower wall  11   b,  and sidewalls  11   c,    11   d.  The receptacle  11  has an opening  11   e,  to which a prong  1  of a male terminal is inserted. The lug  12  has a U-shaped cross-section and includes a base portion  12   b  and sidewalls  12   c,    12   d.    
     As shown in FIG. 2, two pairs of holding pieces  15 ,  16  extend from the sidewalls  12   c,    12   d.  The holding pieces  15 ,  16  are used for holding an electric wire  2 . The holding pieces  15 ,  16  extend from the edges of the sidewalls  12   c,    12   d  of the lug  12  in a direction parallel to the direction from the lower wall  11   b  to the upper wall  11   a.  Before being connected to the lug  12 , the distal part of insulating coating  3  on the wire  2  is removed to expose a core  4 . The wire  2  is placed directly above the base portion  12   b  of the lug  12 . The holding pieces  15 ,  16  are bent toward the central axis of the terminal body  10  to crimp the wire  2  to the lug  12 . In this state, the holding pieces  15  are pressed against the core  4 . The holding pieces  16  are pressed against part of the wire  2  from which the coating  3  is not removed. Accordingly, the wire  2  is electrically connected with the terminal main body  10 . 
     As shown in FIGS.  1 ( b ) and  2 , a main connecting member, which is a main contactor  13  in this embodiment, is located on the lower wall  11   b  of the receptacle  11 . The main contactor  13  extends from a section near the opening  11   e  toward the lug  12 . As shown in FIGS.  1 ( a ) and  2 , the main contactor  13  is a rectangular metal plate. The width of the contactor  13  is smaller than the width a of the opening  11   e,  and the length of the contactor  13  is smaller than the length b of the receptacle  11 . Since the main contactor  13  is made of the same material as that of the terminal main body  10 , the main contactor  13  is integrally formed with the lower wall  11   b  of the receptacle  11 . The main contactor  13  is bent from the lower wall  11   b  toward the center axis of the main body  10 . The distal end of the main contactor  13  is bent to form a curve toward the lower wall  11   b.  The peak of the distal curved portion of the main contactor  13  is a first contact point  13   a.    
     As shown in FIGS.  1 ( b ) and  2 , an auxiliary connecting member, which is an auxiliary contactor  14  in this embodiment, is fixed to the upper wall  11   a  with supports  17 ,  18 . As shown in FIGS.  1 ( a ) and  2 , the auxiliary contactor  14  is a rectangular metal plate. The width of the contactor  14  is smaller than the width a of the opening  11   e,  and the length of the contactor  14  is smaller than the length b of the receptacle  11 . The thickness of the auxiliary contactor  14  is less than that of the metal plate forming the terminal main body  10 . The auxiliary contactor  14  is formed like a diaphragm with its longitudinal center bulging toward the axis of the terminal main body  10 . The peak of the bulge of the auxiliary contactor  14  is a second contact point  14   a.    
     As shown in FIG.  1 ( c ), the auxiliary contactor  14  is formed by bonding two different metals  14   b,    14   c  together. The thermal expansion coefficient of the metal  14   c  is higher than that of the metal  14   b.  In general, an Ni—Fe based material is used as the low thermal expansion coefficient metal  14   b,  and Cu, Ni, Cu—Zn based material, Ni—Cu based material, or Ni—Cr—Fe based material is used as the high thermal expansion coefficient metal  14   c.  When supplied with electric current, the contactor  14  produces heat due to electrical resistance. In this state, since the high thermal expansion coefficient metal  14   c  expands at a greater rate, the contactor  14  is bent toward the side of the high thermal expansion coefficient metal  14   c.  In this embodiment, the auxiliary contactor  14  is bent away from the prong  1  of the male connector. This is because the high heat expansion coefficient metal is located at the side facing the prong  1 , and the low heat expansion coefficient metal is located at the opposite side. 
     The auxiliary contactor  14  is made of metals different from that of the main body  10 . Therefore, the auxiliary contactor  14 , which is made of metals different from the main body  10 , is fixed to the inner surface of the upper wall  11   a  with the supports  17 ,  18 . As shown in FIG.  1 ( b ), the supports  17 ,  18  are formed by bending the longitudinal ends of the upper wall  11   a  inward. 
     The operation of the solderless terminal main body  10  and the prong  1  of the male terminal will now be described. 
     As shown in FIG.  3 ( a ), the prong  1  may be moved in directions A and B. The direction A refers to a direction for inserting the prong  1  into the receptacle  11 . The direction B refers to a direction for removing the prong  1  out of the receptacle  11 . The prong  1  is inserted from the opening  11   e  in the direction A along the axis of the terminal main body  10 . The insertion of the prong  1  is completed when the prong  1  reaches a point close to the lug  12 . In this state, the prong  1  contacts the first contact point  13   a  of the main contactor  13  and the second contact point  14   a  of the auxiliary contactor  14 . The first contact point  13   a  and the second contact point  14   a  are pressed against the prong  1  by elastic forces. The auxiliary contactor  14  has a higher electrical resistance than the main contactor  13 . Thus, when the prong  1  is completely inserted in the receptacle  11 , current flows from the terminal main body  10  to the prong  1  through the first contact point  13   a  of the main contactor  13 . 
     When removing the prong  1  out of the opening  11   e  of the receptacle  11 , the prong  1  is slowly moved in the direction B as shown in FIG.  3 ( b ). In this embodiment, the second contact point  14   a  of the auxiliary contactor  14  is closer to the opening  11   e  than the first contact point  13   a  of the main contactor  13 . The distance between the first contact point  13   a  and the second contact point  14   a  in the longitudinal direction of the receptacle  11  is about one twentieth to one fifth of the length b of the receptacle. Therefore, after being separated from the first contact point  13   a,  the prong  1  remains contacting the second contact point  14   a.  Further, the supports  17 ,  18 , which support the auxiliary contactor  14  at the ends, are formed by bending the ends of the upper  11   a  of the receptacle  11 , which is made of conductive metal. Thus, after the prong  1  is separated from the first contact point  13   a,  the terminal main body  10  remains electrically connected to the prong  1  at the second contact point  14   a  of the auxiliary contactor  14 . 
     Before being deformed, the auxiliary contactor  14  is formed like a diaphragm bulging toward the axis of the terminal main body  10  as illustrated by broken lines in FIG.  3 ( c ). The auxiliary contactor  14  supported by the supports  17 ,  18  at the ends. When electrically the auxiliary contactor  14  is connected with the prong  1  through the second contact point  14   a,  electrical current passes through the auxiliary contactor  14 . At this time, the auxiliary contactor  14  produces heat due to electrical resistance. Since the auxiliary contactor  14  is formed with two different metal, the auxiliary contactor  14  is bulged at the side of the low thermal expansion coefficient metal  14   b,  or away from axis of the main body  10 . Therefore, the curvature of the auxiliary contactor  14  is reversed about the supports  17 ,  18 , and the auxiliary contactor  14  is displaced away from the prong  1 . The change of the curvature separates the auxiliary contactor  14  from the prong  1 . Arc is thus produced at the second contact point  14   a  of the auxiliary contactor  14 . 
     The present embodiment has the following advantages. 
     (1) When removing the prong  1  of the male terminal from the terminal main body  10 , the prong  1  remains contacting the second contact point  14   a  of the auxiliary contactor  14  after being separated from the first contact point  13   a  of the main contactor  13 . In this state, since the prong  1  remains electrically connected to the terminal main body  10  through the second contact point  14   a,  arc is prevented at the first contact point  13   a.  The first contact point  13   a  and the corresponding surface of the prong  1  are not roughened by arc. That is, the contact resistance between the first contact point  13   a  and the prong  1  is not increased, and production of heat due to electrical resistance is suppressed at the first contact point  13   a.  Therefore, if applied to the female connector housing, the solderless terminal main body  10  does not degrades the connector housing even if the an electrical load is connected with a high-voltage power supply. The reliability of the terminal main body  10  is improved. 
     (2) After the prong  1  separated from the fist contact point  13   a  and electrically connected only with the auxiliary contactor  14 , electric current passes through the auxiliary contactor  14 . Then, the auxiliary contactor  14  is heated in an extremely short time and deformed away from the prong  1 . The auxiliary contactor  14  is deformed to be separated from the prong  1 . Arc is thus produced at the second contact point  14   a  of the auxiliary contactor  14 . However, since the auxiliary contactor  14  is deformed to be separated from the prong  1 , the arc produced at the second contact point  14   a  is suppressed. The second contact point  14   a  and the corresponding surface of the prong  1  are not significantly roughened by the arc. The reliability of the terminal main body  10  is therefore further improved. 
     (3) When supplied with electric current, the diaphragm shaped auxiliary contactor  14  is deformed away from the prong  1  of the male terminal. Therefore, since the contactor  14  is supported at the ends by the supports  17 ,  18 , the curvature of the auxiliary contactor  14  is reversed about the supports  17 ,  18 , and the auxiliary contactor  14  is displaced away from the prong  1 . This increases the speed at which the second contact point  14   a  is separated from the prong  1  and thus shortens the time taken for sweeping arc. Therefore, the arc produced at the second contact point  14   a  is further suppressed. As a result, the second contact point  14   a  and the corresponding surface of the prong  1  are less roughened by the arc. The reliability of the terminal main body  10  is therefore further improved. 
     (4) The auxiliary contactor  14  is formed by bonding two metals having different thermal expansion coefficient and is deformed away from the axis of the terminal main body  10  when heated. After dissipating heat by itself, the auxiliary contactor  14  returns to the original shape. Therefore, the number of parts in the terminal main body  10  is reduced, and the size of the main body  10  is reduced. 
     (5) The diaphragm shaped auxiliary contactor  14  is supported at the upper wall  11   a  of the receptacle  11  with both ends held by the supports  17 ,  18 . Compared to a case in which the contactor  14  is supported at one end, the contactor  14  is pressed against the prong  1  by a greater stress. In other words, the auxiliary contactor  14  is strongly pressed against the prong  1  at the second contact point  14   a,  which is the peak of the curved portion. Therefore, the contact pressure between the contactor  14  and the prong  1  is increased by holding the contactor  14  at both ends. 
     (6) The main contactor  13  and the auxiliary contactor  14  face each other with the prong  1  in between. Therefore, the prong  1  is held by the contactors  14 ,  13  at the side of the upper wall  11   a  and the lower wall  11   b  of the receptacle  11 . Thus, the contactors  13 ,  14  are elastically pressed against the prong  1 , and the contact pressure between the contactors  13 ,  14  and the prong  1  is sufficient. This structure does not increases the contact resistance between each of the contactors  13 ,  14  and the prong  1 . The reliability of the terminal main body  10  is therefore improved. 
     It should be apparent to those skilled in the art that the present invention may be embodied in many other specific forms without departing from the spirit or scope of the invention. Particularly, it should be understood that the invention may be embodied in the following forms. 
     In the embodiment of FIGS.  1 ( a ) to  3 ( c ), the terminal main body  10  has a rectangular cross-section. However, the terminal main body  10  may have a substantially circular cross-section or a U-shaped cross-section. Alternatively, the terminal main body  10  may be formed as a flat plate. 
     In the embodiment of FIGS.  1 ( a ) to  3 ( c ), the main contactor  13  is integrally formed with the lower wall  11   b  of the receptacle  11 . However, the main contactor  13  may be formed by attaching a separately formed conductive metal piece to the lower wall  11   b  of the receptacle  11 . 
     In the embodiment of FIGS.  1 ( a ) to  3 ( c ), the main contactor  13  is formed as a metal plate. However, the main contactor  13  need not be formed as a metal plate. For example, the main contactor  13  may be a projection made of conductive metal. 
     In the embodiment of FIGS.  1 ( a ) to  3 ( c ), the auxiliary contactor  14  is formed by boding two different metal plates having different thermal expansion coefficients. However, the auxiliary contactor  14  may be formed by boding three or more metal plates having different thermal expansion coefficients. 
     In the embodiment of FIGS.  1 ( a ) to  3 ( c ), the auxiliary contactor  14  is supported at both ends by the supports  17 ,  18 . However, the support  17 , which located at the opening  11   e,  may be omitted. 
     The main contactor  13  and the auxiliary contactor  14  face each other with the prong  1  in between. However, the main contactor  13  and the auxiliary contactor  14  need not face each other with the prong  1  in between. Specifically, the main contactor  13  and the auxiliary contactor  14  may be located on one of the upper wall  11   a,  the lower wall  11   b,  and the sidewalls  11   c,    11   d  of the receptacle  11 . Alternatively, the main contactor  13  and the auxiliary contactor  14  may be located on two of the walls  11   a  to  11   d  that do not face each other. 
     In the embodiment of FIGS.  1 ( a ) to  3 ( c ), the peak of the bulge of the diaphragm shaped auxiliary contactor  14  functions as the second contact point  14   a.  However, a separately formed metal piece may be attached to the peak of the curved portion of the auxiliary contactor  14  and function as the second contact point  14   a.    
     Therefore, the present examples and embodiments are to be considered as illustrative and not restrictive and the invention is not to be limited to the details given herein, but may be modified within the scope and equivalence of the appended claims.