Patent Document

BACKGROUND 
     1. Technical Field 
     This invention relates to a male connector that is connected to an end of an external electrical cable and is detachably attached to a printed board, and to a printed board assembly equipped with the male connector. 
     2. Background Art 
     A printed board is often provided with an electrical conductive path defining a given circuit pattern and electrical parts such as relays, capacitors, and transistors are mounted on the printed board. Various kinds of electrical devices such as an electrical junction box for a motor vehicle adopt the printed board in order to enhance efficiency in an electrical wiring. An external electrical cable is electrically connected to the electrical conductive path on the printed board so that the electrical devices exert particular functions. 
     A connection between the external electrical cable and the electrical conductive path on the printed board generally utilizes a detachable connector in view of production and assembling works. Specifically, a male terminal coupled to the external electrical cable is electrically connected to a female terminal coupled to the electrical conductive path on the printed board by coupling the male connector to the female connector. Such an electrical device is disclosed in, for example, JP 2005-129275 A (Patent Document 1). 
     However, it is necessary for the conventional connector connection to provide a male connector on an external electrical cable side and a female connector on a printed board side. This will increase the number of parts and will make a producing process complicated. Particularly, in order to obtain a stable connecting condition, it is necessary to strongly attach the female connector to the printed board. As shown in FIG. 6 in Patent Document 1, the female connector must be secured to the printed board by bolts. This will further increase the number of parts and will introduce a complicated structure and troublesome works in producing. 
     [Patent Document 1] JP 2005-129275 A 
     SUMMARY 
     In view of the above problems, an object of the present invention is to provide a new male connector and a new printed board assembly equipped with the male connector that can simplify a connecting structure at a printed board side while maintaining stability in connection between an external electrical cable and an electrical conductive path on a printed board by attaching the male connector to an end of the external electrical cable. 
     In a first embodiment, a male connector is connected to an end of an external electrical cable and is attached to a printed board having an electrical conductive path, so that said male connector electrically connects the external electrical cable to the electrical conductive path. The male connector comprises: a male terminal connected to the end of the external electrical cable; a housing for containing the male terminal; a lock means for detachably holding the housing on the printed board; and a biasing means for applying a biasing force to the male terminal to push and connect the male terminal to the electrical conductive path on the printed board when the housing is held to the printed board by the lock means. 
     According to the male connector in the first embodiment, since the male connector connected to the end of the external electrical cable can be held directly on the printed board, it is possible to eliminate the need for a female connector that has been secured to a printed board in the prior art. This can reduce the number of parts. That is, since the biasing means is provided on the male connector, the electrical conductive path, onto which the male terminal is pushed, is merely formed on the printed board, thereby stably maintaining electrical continuity between the male terminal and the electrical conductive path with the male connector being attached to the printed board. 
     A fixing force of the lock means can prevent the male connector from being disengaged from the housing. A biasing force of the biasing means can surely achieve an electrical connection between the connecting land portion on the electrical conductive path and the distal end portion of the male terminal. Thus, even if the female connector is eliminated, it is possible to obtain strong and secure electrical connection between the external electrical cable and the electrical conductive path. Further, since a complicated structure of attaching the female connector to the printed board can be eliminated, it is possible to simplify the male connector. In addition, an effective area of the printed board becomes great. 
     In a second embodiment, a bend on the male terminal of the male connector constitutes the biasing means. 
     According to the male connector in the second embodiment, the biasing means does not require a particular member and has a simple structure. 
     In a third embodiment, the lock means of the male connector is integrated with the housing. In addition, the lock means includes an engaging portion that protrudes from the housing toward the printed board and engages and disengages the printed board. 
     According to the male connector in the third embodiment, since the lock means for detachably holding the male connector on the printed board is integrated with the housing, it is possible to form the lock means having a simple structure in comparison with the case of using a bolt or a separated engaging member. 
     In a fourth embodiment, the housing of the male connector includes a peripheral wall that surrounds a containing space of the male terminal, a distal end portion of the male terminal protrudes from an opening end surface on the peripheral wall toward the printed board, and the distal end portion of the male terminal can be elastically deformed into the containing space in the housing by the biasing means. 
     According to the male connector in the fourth embodiment, since it is possible to realize stable electrical continuity even if the electrical conductive path is coplanar with the printed board on an area with which an end of the peripheral wall contacts, the male terminal has a simple structure and can be readily produced. It is possible to enhance stability in connector connection by contacting the peripheral wall end of the housing with the printed board when the male terminal is pushed onto the electrical conductive path. In addition, it is easy to confirm a connecting condition between the male terminal and the electrical conductive path. 
     In a fifth embodiment, a printed board assembly is equipped with a male connector. The male connector is detachably attached to a printed board provided with an electrical conductive path. The electrical conductive path on the printed board is provided with a flat connecting land portion that spreads on a surface of the printed board. The printed board is provided on a position outside the connecting land portion with a securing portion to which the lock means of the male connector is held. The male connector is attached to the printed board by holding the lock means on the securing portion. The male terminal of the male connector is pushed to a solder adhered to the connecting land portion on the printed board by a biasing force exerted in the biasing means to maintain electrical continuity between the male terminal and the electrical conductive path. 
     According to the printed board assembly in the fifth embodiment, since the male terminal can be surely held (continued) in the solder on the connecting land portion by the biasing force exerted in the biasing means, it is not necessary to provide an inserting aperture in the printed board and solder the terminal in the inserting aperture. Consequently, not only production of the printed board becomes easy but also a wide area on the rear side of the printed board can be utilized as a mounting surface. This can reply to current requirement for high density on the printed board. 
     In a sixth embodiment, the housing includes a peripheral wall that surrounds a containing space of the male terminal of the male connector, a distal end portion of the male terminal protrudes from an opening end surface of the peripheral wall toward the printed board, and a length of the male terminal protruding outward from the opening end surface of the peripheral wall is set to be smaller than a thickness of a solder on the connecting land portion on the printed board. 
     According to the printed board assembly in the sixth embodiment, it is possible to prevent the distal end (the pushing end) of the male terminal from penetrating the solder on the connecting land portion. That is, although the present invention does not exclude the embodiment in which the distal end of the male terminal penetrates the connecting land portion or the solder on the connecting land portion, it is possible for the distal end portion of the male terminal to avoid to penetrate the solder by adjusting a projecting length of the distal end portion of the male terminal to be a given length, and is possible to restrain faults in electrical continuity and instability in association with the penetration. 
     Since the male terminal connected to the end of the external electrical cable is pushed onto and connected to the electrical conductive path on the printed boar with the biasing force being applied to the male terminal, it is possible to simplify the connecting structure at the printed board side while maintaining stability in connection between the electrical conductive path on the printed board and the external electrical cable. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a longitudinal section view of an embodiment of a printed board assembly equipped with a male connector in accordance with an exemplary embodiment. 
         FIG. 2  is a plan view of a main part of the printed board constituting the printed board assembly shown in  FIG. 1 . 
         FIG. 3  is an enlarged section view of a main part of the printed board shown in  FIG. 2 . 
         FIG. 4  is a longitudinal section view of the male connector constituting the printed board assembly equipped with the male connector shown in  FIG. 1 . 
         FIG. 5  is a section view of a main part of the printed board assembly equipped with the male connector. 
         FIG. 6  is an enlarged section view of a main part of a structure that can be adopted as the printed board assembly equipped with the male connector in accordance with an exemplary embodiment. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     Referring now to the drawings, exemplary embodiments of the will be described below. 
       FIG. 1  shows an embodiment of a printed board assembly  10  equipped with a male connector  14  in accordance with an exemplary embodiment. The printed board assembly  10  includes a printed board  12  and the male connector  14  detachably mounted on the printed board  12 . Hereinafter, a vertical direction designates upper and lower directions in  FIG. 1 . 
     Specifically, as shown in  FIGS. 2 and 3 , the printed board  12  includes a hard insulation plate  16 , and electrical conductive paths  18   a  and  18   b  provided with both sides of the insulation plate  16  to define a double side printed wiring plate. In particular, the electrical conductive path  18   a  on a board front side  19  of the insulation plate  16  is provided in recesses  20  in the board front side  19 . Thus, it is possible for each of the recesses  20  to restrain a height of each of cream solders  26  adhered to each of connecting land portions  22  (mentioned after) from protruding from the board front side  19 . 
     The electrical conductive path  18   b  on a rear side of the insulation plate  16  is provided on a rear side of an area on which the connecting land portions  22  (mentioned after) are provided. Although the rear side electrical conductive path  18   b  is provided directly on the rear side of the insulation plate  16  in the present embodiment, recesses may be provided in a rear side of the insulation plate  16  and the electrical conductive path  18   b  may be formed in the recesses, as is the case with the electrical conductive path  18   a  on the board front side  19 . 
     Ten connecting land portions  22  are provided on the electrical conductive path  18   a  on the board front side  19  of the insulation plate  16 . All of the connecting land portions  22  are formed into rectangular flat plate-like configurations having the same sizes. 
     Five connecting land portions  22  define each of two lines. The connecting land portions  22  are separated equally from one another every line. The connecting land portions  22  on two lines are disposed on the same positions in an arranging direction. 
     The connecting land portions  22  are formed into flat surfaces coplanar to the board front side  19  of the insulation plate  16 . Each cream solder  26  is adhered to the surface of each connecting land portion  22 . 
     The printed board  12  is provided with two securing apertures  28  on the outside of the connecting land portions  22 . The securing apertures  28  are formed into rectangular shapes having the same sizes and penetrate the insulation plate  16  in its thickness direction. Each of the securing apertures  28  is disposed on opposite sides of the connecting land portions  22  in the arranging direction. 
     As shown in  FIG. 4 , in the male connector  14  to be attached to the printed board  12 , male terminals  30  are contained in a housing  32 . 
     Each male terminal  30  is formed into a rod shape by pressing a metallic sheet coated with an electrical conductive plating layer. The male terminal  30  is provided on a proximal end with a press-contact portion (not shown). The press-contact portion of the male terminal  30  is crimped on an end of an external electrical cable  34 . Thus, the male terminals  30  and external electrical cables  34  are electrically interconnected with one another. This crimping process of the press-contact portions can adopt a conventional crimping process that has been well known in the prior art. 
     Each male terminal  30  is provided on a middle part with an S-shape bend  36  that serves as a biasing means. Thus, each bend  36  permits each male terminal  30  to elastically deform in its longitudinal direction. The bend  36  is not limited to the S-shape. For example, it may be formed into a spiral shape. The biasing means may not be always provided on the male terminal  30 . For example, the biasing means may elastically support an upper wall  42  of a housing  32  (described below) on a peripheral wall  40 . 
     A distal end portion  38  of each male terminal  30  is tapered so that a cross section is decreased gradually from a proximal end to a distal end in a longitudinal direction. The distal end portion  38  is not limited to this tapered shape. For example, it may be formed into a bend. If the distal end portion  38  is bent, the bend  36  may be provided on the distal end portion  38  as the biasing means. 
     The housing  32  that contains the male terminals  30  is made of synthetic resin and includes a peripheral wall  40  having a rectangular frame-like configuration and an upper wall  42  that closes an upper opening in the peripheral wall  40 . 
     A pair of wall portions  44  of the peripheral wall  40  are opposed to each other in a longitudinal direction (right and left directions in  FIG. 2 ) and are provided with support portions  46  extruding outward. Each support portion  46  is provided on its projecting end with a lock portion (lock means)  48 . 
     The lock portion  48  is made of synthetic resin and is generally formed into a rectangular thick plate. The lock portion  48  is provided on an end in a longitudinal direction with an engaging portion  50  projecting in a thickness direction. 
     The engaging portion  50  is formed into a substantially right triangle in cross section in a width direction (a direction vertical to a paper in  FIG. 4 ) to extend straightly. Thus, the engaging portion  50  is provided with an engaging surface  52  that spreads in a direction orthogonal to the longitudinal direction of the lock portion  48  and with a slant surface  54  that gradually decreases its height from the lock portion  48  smaller than that of the engaging surface  52  toward an end side in the longitudinal direction of the lock portion  48 . 
     Such lock portion  48  is integrated with a projecting end of a support portion  46  on a substantially middle part on one side provided with the engaging portion  50  in a thickness direction. The lock portion  48  extends in a height direction of the housing  32  in parallel to the wall portion  44 . The engaging portion  50  is disposed outside an opening end surface  56  of the peripheral wall  40  in an opening direction. 
     When the housing  32  is attached to the printed board  12 , an upper bottom wall  42  is provided with pushing apertures (not shown) at positions corresponding to the connecting land portions  22  on the printed board  12 . A proximal end of each male terminal  30  is pushed into each pushing aperture from an inside of the housing  32 . Thus, the male connector  14  is formed. 
     As described above, when the proximal end of each male terminal  30  is pushed into the pushing aperture, a middle part of the male terminal  30  in the longitudinal direction is disposed within the peripheral wall  40 , and the distal end portion  38  of each male terminal  30  protrudes outside the opening end surface  56  of the peripheral wall  40 . A projecting height H of the male terminal  30  from the opening end surface  56  is set to be smaller than a thickness h of the cream solder  26 . 
     The male connector  14  is pushed onto the printed board  12  when a lower end of the lock portion  48  of the housing  32  is positioned in the securing aperture  28  in the printed board  12  from a front side of the printed board  12  and the distal end portion  38  of each male terminal  30  protrudes toward each connecting land portion  22  on the printed board  12 . At this time, a peripheral edge around each securing aperture  28  slides on the slant surface  54  of each engaging portion  50 , a lower end of the lock portion  48  is deflected outward in the longitudinal direction of the housing  32 , and the male connector  14  approaches the printed board  12 . When a sliding action between the slant surface  54  of the engaging portion  50  and the peripheral edge around the securing aperture  28  is finished and the engaging portion  50  passes the securing aperture  28  to be disposed at a rear side of the printed board  12 , the lock portion  50  returns to the original state by its elasticity. Thus, the engaging surface  52  of the engaging portion  50  is superimposed on the peripheral edge around the securing aperture  28  from a rear side of the printed board  12  and the engaging portion  50  is engaged with the peripheral edge around the securing aperture  28  from the rear side of the printed board  12 . Consequently, the male connector  14  is attached to the printed board  12  with the printed board  12  being clamped between the engaging portion  50  and the opening end surface  56  of the peripheral wall  40  of the housing  32 . 
     When the male connector  14  is attached to the printed board  12 , the distal end portion  38  of the male terminal  30  protrudes outward from the opening end surface  56  of the housing  32 , and the distal end portion  38  is pushed back to the housing  32 . However, since the bend  36  deforms elastically, the distal end portion  38  is retracted into the housing  32  (see  FIG. 2 ). An amount of deflection of the bend  36  is slightly exaggerated for purposes of illustration in  FIG. 2 . 
     As shown in  FIG. 5 , the distal end portion  38  of each male terminal  30  retracted in the housing  32  sticks the cream solder  26  on each connecting land portion  22  by a returning force (biasing force) to the original state exerted in each bend  36 . In result, each external electrical cable  34  and each electrical conductive path  18   a  are electrically connected through each male terminal  30  to each other. In the present embodiment, the biasing force of the bend  36  is controlled so that the distal end portion  38  of the male terminal  30  is held to stick the cream solder  26 . The distal end portion  38  of the male terminal  30  may stick the connecting land portion  22 . 
     The male connector  14  attached to the printed board  12  by the manner described above can be released from the engagement with the opening edge around each securing aperture  28  by means of each engaging portion  50  by pushing an upper end of each lock portion  48  from the outside to the inside in the longitudinal direction of the housing  32  so that lower ends of the respective lock portions  48  are separated away each other in the longitudinal direction of the housing  32 . When the engaging portion  50  is disengaged from the opening peripheral edge around the securing aperture  28 , the male connector  14  can be detached from the printed board  12  by displacing the engaging portion  50  through the securing aperture  28  from the rear side of the printed board  12  to its front side. 
     Since the male connector  14  is secured directly to the printed board  12  in the printed board assembly  10 , it is not necessary to provide a female connector, which has been required in the prior art, on the printed board  12 . In result, it is possible to reduce the number of parts that are required to attach the male connector  14  to the printed board  12 . 
     When the male connector  14  is held to the printed board  12 , since the distal end portion  38  of the male terminal  30  is held to stick the cream solder  26  by the biasing force exerted in the bend  36 , it is possible to surely establish electrical continuity between the male terminal  30  and the electrical conductive path  18   a . Thus, it is not necessary to provide the printed board  12  with an inserting aperture through which the distal end portion  38  of the male terminal  30  passes and to solder the distal end portion  38  that passes the inserting aperture to the printed board  12 . Consequently, it is possible to form the electrical conductive path  18   b  on the rear side corresponding to the attaching position of the male connector  14  on the printed board  12 . 
     Since the distal end portion  38  of the male terminal  30  is tapered, the distal end portion  38  can stick the cream solder  26  positively, even if an oxide film is formed on a surface of the cream solder  26 . Thus, electrical continuity between the male terminal  30  and the electrical conductive path  18   a  can be obtained. 
     Since the male terminal  30  protrudes outward from the opening end surface  56  of the housing  32 , electrical continuity between the male terminal  30  and the electrical conductive path  18   a  can be maintained stably, even if the electrical conductive path  18   a  is provided in the recesses  20  in the printed board  12 . 
     Since the male terminal  30  and electrical conductive path  18   a  are interconnected to each other so long as the opening end surface  56  of the housing  32  is superimposed on the printed board  12 , it is easy to confirm a connecting condition between the male terminal  30  and the electrical conductive path  18   a.    
     Since the projecting height H of the male terminal  30  from the opening end surface  56  is set to be smaller than the thickness h of the cream solder  26 , it is possible to avoid a trouble that the distal end portion  38  of the male terminal  30  penetrates the cream solder  26  and the connecting land portion  22  with the male connector  14  being attached to the printed board  12 . In result, it is possible to prevent a failure in electrical continuity between the male terminal  30  and the electrical conductive path  18   a.    
     Since the bend  36  provided on the male terminal  30  constitutes the biasing means, it is not necessary to provide another member for biasing the male terminal  30 . Consequently, it is possible to simplify the male connector  14 . 
     Since the lock portion  48  integrated with the housing  32  constitutes the lock means, it is possible to simplify the lock means in comparison with the case of using bolts or the like in the prior art. 
     Since the opening end surface  56  of the housing  32  is superimposed on the surface of the printed board  12  with the male connector  14  being attached to the printed board  12 , it is possible to stably maintain attaching condition between the male connector  14  and the printed board  12 . 
     Although embodiments are described above specifically, it should be noted that the present invention is not limited to the embodiments. For example, the lock means can include a bolt-fastening means. Also, a reinforcing member such as a hardware or resin may be attached to the lock means in order to reinforce the printed board. 
     In the case where a portion to be stuck by the male terminal in the electrical conductive path on the printed board protrudes from the surface of the printed board, the distal end portion of the male terminal may not be protrude from the opening end surface of the peripheral wall of the housing. 
     The biasing force of the bend  36  can be controlled discretionarily. The distal end portion  38  of the male terminal  30  may penetrates the cream solder  26  or the connecting land portion  22 . 
     As shown in  FIG. 6 , the surfaces of the connecting land portions  22  may be covered with solder levelers  24  and the cream solders  26  may be adhered to the solder levelers  24 . In this case, a connecting function between the cream solders  26  and the connecting land portions  22  can be improved and the male terminals  30  can readily stick the soft cream solders  26 . The distal end portions  38  of the male terminals  30  may penetrate the solder levelers  24  by controlling the biasing force of the bends  36 .

Technology Category: h