Patent Document

CROSS-REFERENCE TO RELATED APPLICATIONS  
         [0001]    This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2001-384787, filed Dec. 18, 2001, the entire contents of which are incorporated herein by reference.  
         BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    The present invention relates to a connector and electric connection structure applicable to electric connection parts of harness connected to a load of a large electric power or electric connection parts of fuse blocks in a wiring system which is used in automobiles and the like, and more particularly to a connector and electric connection structure capable of preventing vehicle fire or the like due to melting or discharge spark of connector terminals by electric discharge when inserting and removing.  
           [0004]    2. Description of the Related Art  
           [0005]    Along with a rapid electronic progress in the entire society, comfort and convenience are demanded, for example, in the automobile which is one of the transportation means hitherto regarded only as a moving tool, and various electronic parts have come to be installed such as car navigation system and electronically controlled suspension system which operate under the central control system by a computer. In addition to the pursuit of comfort and convenience, environmental problems represented by automotive emission are global issues, and automotive devices are in the trend of shift from mechanical control to electrical control. For example, the power of the power steering system was conventionally obtained from the rotating force of the engine. However, recently an electric power steering device for generating power electrically is mounted, and it is attempted to use so-called clean electric energy without polluting the environments. As the automotive devices are going electronic, the electric load of automotive devices used in the automobile, which is hundreds of watts (W) at maximum at the present, is predicted to increase to 5 to 6 kW in future, and at the same time the electric power must be supplied efficiently, and it is proposed to elevate the vehicle supply voltage from 14 volts (V) at the present to 42 volts.  
           [0006]    However, during operation of automotive devices of such large electric power load, when the connector of the wire harness for connecting the devices is pulled out or inserted, the so-called arc discharge is generated, and its energy may not only melt down the connector terminal, but also induces a discharge spark in succession. In an extreme case, a vehicle fire may take place. One of the causes is a prolonged state of incomplete connection relation between the connector and connector terminal. Or if the vehicle is driven while the connector is not coupled or fitted only halfway, contact and separation of the first connection terminal and second connection terminal of the connector are intermittently repeated due to vibration during travel, and the so-called chattering occurs. In such a case, too, arc discharge occurs continuously.  
         BRIEF SUMMARY OF THE INVENTION  
         [0007]    An object of the present invention is to provide a connector and electric connection structure capable of preventing vehicle fire or the like due to continuous melting or discharge spark of connector terminals by arc discharge when inserting and removing the connector.  
           [0008]    According to an aspect of the present invention, there is provided a connector comprising: a first connector having a first connector housing which supports plural first connection terminals in its inside; a second connector having a second connector housing which supports plural second connection terminals connected to the plural first connection terminals in its inside; and a magnetic member disposed in at least one of the first connector housing and second connector housing, wherein the magnetic member is disposed so as to be held between leading ends of the plural first connection terminals or between leading ends of the plural second connection terminals, and a magnetic field is generated in a direction orthogonal to a direction in which the both first and second connection terminals are inserted during a period of time from complete engagement of the first and second connectors to complete disengagement thereof, or a period of time from complete disengagement the first and second connectors to complete engagement thereof.  
           [0009]    Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter. 
       
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING  
       [0010]    The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate presently preferred embodiment of the invention, and together with the general description given above and the detailed description of the preferred embodiment given below, serve to explain the principles of the invention.  
         [0011]    [0011]FIG. 1 is a perspective view showing a connector for wiring connection according to an embodiment of the invention;  
         [0012]    [0012]FIG. 2 is a front view showing a first connector of the connector for wiring connection;  
         [0013]    [0013]FIG. 3 is a longitudinal sectional view showing a half fitted state of two connectors of the connector for wiring connection;  
         [0014]    [0014]FIG. 4 is a diagram for explaining the trajectory of arc discharge occurring between two connection terminals;  
         [0015]    [0015]FIG. 5 is a graph showing the relation between the discharge continuation time and the degree of melting loss of terminals;  
         [0016]    [0016]FIG. 6 is a front view showing another first connector of the connector for wiring connection;  
         [0017]    [0017]FIG. 7 is a longitudinal sectional view showing a half fitted state of other two connectors of the connector for wiring connection;  
         [0018]    [0018]FIG. 8 is a perspective view showing a connector for wiring connection according to another embodiment of the invention; and  
         [0019]    [0019]FIG. 9 is a schematic front view showing a magnetic field generated in a first connector of the connector for wiring connection. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0020]    Referring now to the accompanying drawings, an embodiment of the invention will be described below.  
         [0021]    [0021]FIG. 1 is a perspective view showing a connector for wiring connection according to an embodiment of the invention, FIG. 2 is a front view showing a first connector of the connector for wiring connection, and FIG. 3 is a longitudinal sectional view showing a half fitted state of two connectors.  
         [0022]    A connector for wiring connection  10  of this embodiment is composed of, for example, a first connector (plug connector)  20  and a second connector (receptacle connector)  30  each having connection terminals for a large electric power load disposed in two stages in the vertical direction.  
         [0023]    The first connector  20  is composed as follows. That is, in a first connector housing  21  formed of a synthetic resin or the like, plural terminal accommodating holes  22  extending in the connector fitting direction are formed in two stages in the vertical direction of the first connector housing  21 , and a first connection terminal  25  press-fitted to a leading end of an electric wire  24  branched off from a harness (not shown) for connection of a large electric power load is accommodated in the terminal accommodating holes  22 . In the housing frame portion between the terminal accommodating holes  22 , a magnetic member (a rectangular permanent magnet  28  in this embodiment) is incorporated. This permanent magnet  28  is preferably disposed at a position exposed to the strongest magnetic force in a place where arc discharge occurs, for example, between the first and second connection terminals  25  and  35 . The magnet  28  is incorporated in the housing frame portion so that, for example, the upper direction may be the S pole and the lower direction may be the N pole in FIG. 1. A stopping pawl  26  having an elastic stopping piece is formed on outer wall of the first connector housing  21  in the upper direction in FIG. 1.  
         [0024]    On the other hand, the second connector  30  is composed as follows. That is, in a second connector housing  31  formed of a synthetic resin or the like, a second connection terminal  35  press-fitted to a leading end of an electric wire  34  branched off from a harness (not shown) for connection of a large electric power load is formed in two stages in the vertical direction of the second connector housing  31 , corresponding to the first connection terminal  25  of the first connector  20 , and is accommodated in plural terminal accommodating holes  32  extending in the connector fitting direction. On the outer wall of the second connector housing  31  in the upper direction in FIG. 1, a stopping portion  36  is formed for stopping and fixing the both connectors  20 ,  30  as being engaged with the stopping pawl  26  formed in the first connector housing  21  when the both connectors  20 ,  30  are fitted completely. Together with the stopping pawl  26 , it composes a lock mechanism of the connector for wiring connection  10 .  
         [0025]    According to the connector for wiring connection  10  having such configuration, when engaging/disengaging the first connector  20  with/from the second connector  30 , as shown in FIG. 3, Lorentz force is generated by the action of a magnetic field T generated in a direction orthogonal to the direction in which the both connection terminals  25 ,  35  are fitted by the permanent magnet  28  disposed in the first connector housing  21 . Accordingly, for example, as depicted by parabola a in FIG. 4, the electron of arc generated between the both connection terminals  25  and  35  is bent, and the trajectory of the arc discharge is drawn very far from the direct distance between the two connection terminals  25  and  35 . Therefore, destructive effects of the arc discharge on the connection terminals  25  and  35  can be decreased, so that melting of connection terminals can be prevented effectively. In the case of the connector for wiring connection without permanent magnet  28 , usually, arc discharge is terminated when the both connection terminals are apart from each other by a specified distance. However, when the permanent magnet  28  is provided in the first connector housing  21  as in the case of the connector for wiring connection  10  of this embodiment, the specified distance can be instantly reserved on the moment of change from contact to separation, or from separation to contact of the two connection terminals  25 ,  35 .  
         [0026]    The difference in effects on the arc whether or not the permanent magnet  28  is provided in the first connector housing  21  is known from the graph in FIG. 5. That is, according to the experiment by the applicant of the invention, without the permanent magnet  28 , the discharge continuation time was t, and the terminal melt loss degree was u, and with the permanent magnet  28 , the discharge continuation time was about {fraction (1/16)} or less, and the terminal melt loss was about {fraction (1/10)} or less. This difference is variable by adjustment of the magnetic force of the permanent magnet  28 , change of arrangement position or the like, and further better results may be obtained.  
         [0027]    Also depending on the mode of arrangement of the connection terminal  25  ( 35 ), the effect of the permanent magnet  28  varies. Thus, as shown in FIG. 6, for example, the connection terminal  25  ( 35 ) may be disposed in a symmetrical state to the permanent magnet  28  (for example, in a confronting state of plate faces of the connection terminals  25   a  and  25   b ). In this configuration, since the connection terminals  25   a ,  25   b  can be further brought closer to the permanent magnet  28 , and a strong magnetic field is realized by the connection terminals  25   a ,  25   b . Destructive effects of arc discharge on the connection terminal  25  ( 35 ) can be further decreased, thereby melting of connection terminals can be effectively prevented.  
         [0028]    In this embodiment, the permanent magnet  28  is disposed in the first connector housing  21 . To the contrary, as shown in FIG. 7, the permanent magnet  28  may be disposed in the second connector housing  31 . As the magnetic member, instead of the permanent magnet  28 , for example, an electromagnet or the like may be also used.  
         [0029]    [0029]FIG. 8 is a perspective view showing a connector for wiring connection according to another embodiment of the invention, and FIG. 9 is a schematic front view showing a magnetic field generated in a first connector of the connector for wiring connection.  
         [0030]    The connector for wiring connection  10 ′ of this embodiment is composed of a first connector (plug connector)  20 ′ and a second connector (receptacle connector)  30 ′, for example, having connection terminals for large electric power load disposed in two stages in the vertical direction.  
         [0031]    The first connector  20 ′ is composed as follows. That is, in a first connector housing  21 ′ formed of synthetic resin or the like, plural terminal accommodation holes  22 ′ extending in the connector fitting direction are formed in two stages in the vertical direction of the first connector housing  21 ′, and a first connection terminal  25 ′ crimped to the leading ends of wires  24 ′ branched off from a connection harness (not shown) for large electric power load is accommodated in the terminal accommodation holes  22 ′. In the housing frame portion between these terminal accommodation holes  22 ′, a magnetic member (a rectangular permanent magnet  28 ′ in this embodiment) is incorporated. The permanent magnet  28 ′ is preferably disposed at a position exposed to the strongest magnetic force, for example, where arc discharge occurs between the first and second connection terminals  25 ′,  35 ′, and specifically incorporated in the housing frame portion such that the upper direction is the S pole and the lower direction is the N pole in FIG. 8. In the outer walls at upper and lower positions in FIG. 8 of the first connector housing  21 ′, engagement recesses  52  for engaging with a yoke  50  are formed, respectively. The yoke  50  is a U-shaped ferromagnetic element composed of an annular portion  55  formed along an outer periphery of a front side of the first connector housing  21 ′, and an engaging piece  51  extending at right angle to the annular portion  55  from the upper and lower parts of the annular portion  55 . The engaging piece  51  of the yoke  50  is engaged with the engagement recess  52  of the first connector housing  21 ′, and an engaging projection  53  of the engagement recess  52  is fitted into an engaging hole  54  of the engaging piece  51 , so that the yoke  50  is attached to the first connector housing  21 ′. The yoke  50  is disposed such that the magnetic field T generated by the permanent magnet  28 ′ having the first connection terminal  25 ′ pinched by the engaging pieces  51  is concentrated on the first connection terminal  25 ′ as shown in FIG. 9. On the outer wall in the direction of A in FIG. 8 of the first connector housing  21 ′, a locking claw  26 ′ having an elastic stopping piece is formed.  
         [0032]    On the other hand, the second connector  30 ′ is composed as follows. That is, in a second connector housing  31 ′ formed of synthetic resin or the like, in correspondence to the first connection terminal  25 ′ of the first connector  20 ′, a second connection terminal  35 ′ crimped to the leading ends of wires  34 ′ branched off from a connection harness (not shown) for large electric power load is formed in two stages in the vertical direction of the second connector housing  31 ′, and accommodated in plural terminal accommodation holes  32 ′ extending in the connector fitting direction. On the outer wall in the direction of A in FIG. 8 of the second connector housing  31 ′, a locking portion  36 ′ is formed for locking and fixing the both connectors  20 ′,  30 ′ by engaging with the both connectors  20 ′,  30 ′ (it, together with the locking claw  26 ′, composes a lock mechanism of the connector for wiring connection  10 ′).  
         [0033]    According to the connector for wiring connection  10 ′ thus configured, when fitting/separating the first connector  20 ′ and second connector  30 ′, a Lorentz force is generated by the action of the magnetic field T generated so as to be concentrated in a direction orthogonal to the engaging direction of the both connection terminals  25 ′,  35 ′ by the permanent magnet  28 ′ and yoke  50  disposed in the first connector housing  21 ′. Then, the electron of the arc generated between the both connection terminals  25 ′,  35 ′ is bent, and the trajectory of arc discharge is drawn far remote from the linear distance between the connection terminals  25 ′,  35 ′. This makes it possible to reduce destructive effects of the arc discharge on the both connection terminals  25 ′,  35 ′, and melting loss of connection terminals can be prevented further effectively. Also in this embodiment, the permanent magnet  28 ′ is disposed in the first connector housing  21 ′. To the contrary, the permanent magnet  28 ′ may be disposed in the second connector housing  31 ′, and aside from the permanent magnet  28 ′, for example, an electromagnet may be also used.  
         [0034]    Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.

Technology Category: 5