Abstract:
A waterproof connector is provided for ensuring an appropriate intimate contact state to a sealing member without impairing easy assembly. The connector includes a housing that holds at least one contact for establishing an electrical connection with a mating connector; and a ring-shaped sealing member mounted on the housing, the sealing member having a front face and a rear face; at least a first and a second guide portion provided adjacent to each of both faces of the sealing member, the guide portions guiding the housing when being mounted to a case.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims priority under 35 U.S.C. §119 to Japanese Patent Application No. 2011-258530, filed Nov. 28, 2011. 
       FIELD OF THE INVENTION 
       [0002]    The present invention relates to a waterproof connector provided at a place that may be exposed to water. 
       BACKGROUND 
       [0003]    Conventionally, a waterproof structure is adopted in an electrical connector to be used in an electronic device provided at a place that may be exposed to water, such as an engine room. In this waterproof connector, water is prevented from entering by using a ring-shaped sealing member to form a sealing part. 
         [0004]    An example is disclosed in Japanese Patent Application Laid-Open No. 2009-9845 in which a connector is divided into a board connector to be assembled to a circuit board and an outer housing to be assembled to a case. The outer housing has a receiving part in which a connector housing for holding a contact of the board connector is accommodated. The case, the housings, and the board connector are assembled so that a predetermined clearance is provided between the connector housing and the receiving part of the outer housing and between the outer housing and the case. For this reason, with an assembling tolerance between the board connector and the housing and an assembling tolerance between the housing and the case, an assembling tolerance between the case and the connector can be absorbed. 
         [0005]    Also, in Japanese Patent Application Laid-Open No. 2007-128715, a rubber-made grommet is fixed to a case cover of an electronic device to ensure a waterproof property between an electrical connector (a board connector) mounted on a circuit board on an electronic device side and the case cover. 
         [0006]    In a waterproof connector in which a sealing member is elastically deformed to be brought into intimate contact with a sealing surface on the counterpart side, if a portion of the sealing member is compressed to a too small degree at any position on the circular sealing member, the waterproof property may not be ensured. Conversely, if a portion is deformed too strongly, the sealing member is twisted to become disengaged from a fixed position, and therefore the waterproof property may not be ensured either in this situation. Therefore, what is important for the waterproof connector to ensure the waterproof property is that the sealing member is deformed with a necessary amount to be brought into intimate contact with the sealing surface on the counterpart side, that is, to acquire an appropriate intimate contact state. However, it is not easy to assemble the waterproof connector and the case without misalignment therebetween. Moreover, the patent publications cited above do not suggest that an appropriate intimate contact state is provided to the sealing member. 
       SUMMARY 
       [0007]    Therefore, the present invention has been made in view of the above-described problems, and has an object of providing a waterproof connector capable of providing an appropriate intimate contact state to a sealing member not requiring another member, without impairing easy assembly. 
         [0008]    A waterproof connector includes a housing that holds at least one contact for establishing an electrical connection with a mating connector; and a ring-shaped sealing member mounted on the housing, the sealing member having a front face and a rear face; at least a first and a second guide portion provided adjacent to each of both faces of the sealing member, the guide portions guiding the housing when being mounted to a case. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    The objects, features and advantages of the invention will become more apparent by describing in detail embodiments thereof with reference to the accompanying drawings, in which: 
           [0010]      FIG. 1  is a perspective view of a connector assembly in an embodiment; 
           [0011]      FIGS. 2A ,  2 B, and  2 C each show the connector assembly in the present embodiment,  FIG. 2A  being a plan view,  FIG. 2B  being a sectional view of  FIG. 2A  taken along line  2   b - 2   b , and  FIG. 2C  being a partially enlarged view of  FIG. 2B ; 
           [0012]      FIGS. 3A and 3B  each show a male connector in the present embodiment,  FIG. 3A  being a perspective view and  FIG. 3B  being a sectional view of  FIG. 3A  taken along line  3   a - 3   a;    
           [0013]      FIGS. 4A and 4B  each are a plan view of the male connector in the present embodiment; 
           [0014]      FIGS. 5A and 5B  each show a procedure of assembling the male connector in the present embodiment on an electronic device,  FIG. 5A  showing the state in which the male connector is assembled on a circuit board and  FIG. 5B  showing the state in which a housing cover starts to be inserted; and 
           [0015]      FIGS. 6A and 6B  each show the procedure of assembling the male connector in the present embodiment on the electronic device,  FIG. 6A  showing the state in which the housing cover reaches a sealing member and  FIG. 5B  showing the state in which the housing cover has been deeply pressed to the bottom. 
       
    
    
     DETAILED DESCRIPTION 
       [0016]    The present invention is described in detail below based on embodiments shown in the accompanying drawings. 
         [0017]    A connector assembly  10  according to an embodiment is, as shown in  FIG. 1  and  FIGS. 2A to 2C , a waterproof connector for use as being assembled onto an electronic device  1 . The electronic device  1  has a case  3  whose outer periphery is provided with a circuit board  2 , and further includes a case cover  4  made of metal covering an outer periphery of the circuit board  2 . The connector assembly  10  is configured with a male connector  20  and a female connector  40  mated with each other, the male connector  20  to be electrically connected to the circuit board  2  and the mating female connector  40  serving as a counterpart connector with respect to the male connector  20 . The case cover  4  has formed therein an essentially rectangular connector placement window  5  where the male connector  20  is to be placed. The male connector  20  penetrates through this connector placement window  5  to be partially accommodated in the case cover  4  for connection with the circuit board  2  placed in the case cover  4  and to be partially exposed to the outside of the case cover  4 . The case cover  4  includes a flange-shaped sealing wall  6  standing from an outer periphery of the case cover  4  along the connector placement window  5 . Note that various electronic elements and wiring patterns not shown are mounted on the circuit board  2 . 
         [0018]    Note that in each drawing, a sealing member  35 , for instance a resilient washer or gasket which may be fabricated from elastically deformable rubber, is shown in an undeformed state for ease of understanding its shape. The same applies to a sealing member  46 , which will be described further below. 
         [0019]    As shown in  FIGS. 3A ,  3 B,  4 A and  4 B, the male connector  20 , which is the waterproof connector of the present invention, includes a male housing  21  and a plurality of male contacts  22  accommodated in the male housing  21 . However, the waterproof connector may of course also be a female connector, the mating connector then being a male connector. Note that in the male connector  20 , a side to be connected to the counterpart female connector  40  is defined as front and a side opposite thereto and from which a wire not shown is drawn is defined as rear. The same applies to the female connector  40 , a side to be connected to the counterpart male connector  20  being defined as front. 
         [0020]    The male housing  21  is an injection-molded resin-made insulating product, and includes a base  23 , two receiving parts  24  provided on a front side of the base  23 , and three fixing seats  38  positioned on a rear end side of the receiving parts  24  to fix the male connector  20  to the case  3 . 
         [0021]    As shown in  FIGS. 3A and 3B , the base  23  has an oval outer shape, and is formed as being extended to the outside of the receiving parts  24 , which will be described further below, in a diameter direction. 
         [0022]    The base  23  includes a seal placing part  30 , a seal supporting part  31  provided on a rear side of the seal placing part  30 , and a holder placing part  33  provided on a front side of the seal placing part  30 , all parts along a circumferential direction. Note that, as shown in  FIG. 3B , the holder placing part  33  has formed therein a holding groove  33   a  along a major axial direction of the base  23  to hold a tail end side of a seal holder  36 . 
         [0023]    The seal placing part  30  has a flat outer peripheral surface over the entire length in a circumferential direction, with its periphery having the sealing member  35  (e.g. fabricated from rubber) fitting in. 
         [0024]    The seal supporting part  31  is formed with its diameter largely extended to the outside of the seal placing part  30 . Therefore, when the sealing member  35  fits in the seal placing part  30 , the seal supporting part  31  supports the sealing member  35  from the rear side to prevent misalignment of the sealing member  35  to the rear side. The seal supporting part  31  has an outer peripheral surface on which six guide projections  32  (first guide portions) are formed so as to be spaced apart from each other in a circumferential direction. The outer peripheral surface of the seal supporting part  31  is formed as a flat surface over the circumferential direction, except these guide projections  32 . 
         [0025]    Each of both ends of the seal supporting part  31  in a major axial direction (an x direction in  FIG. 3A ) is provided with one guide projection  32 . These guide projections  32  are referred to as guide projections  32   x . The other four projections  32  are each provided to a boundary between a large curvature portion and a small curvature portion of the seal supporting part  31 . These guide projections  32  are referred to as guide projections  32   y.    
         [0026]    The guide projections  32   x  engage with an inner peripheral surface of the sealing wall  6  when the male connector  20  is inserted into the connector placement window  5  of the case cover  4 , thereby regulating relative positions of the male connector  20  and the case cover  4  (the sealing wall  6 ) in a major axial direction. Similarly, the guide projections  32   y  engage with the inner peripheral surface of the sealing wall  6 , thereby regulating relative positions of the male connector  20  and the case cover  4  (the sealing wall  6 ) in a minor axial direction (a y direction in  FIG. 3A ). 
         [0027]    The seal holder  36  is provided on a front side of the seal supporting part  31  (the sealing member  35 ) of the base  23 . When the sealing member  35  fits in the seal placing part  30 , the seal holder  36  supports the sealing member  35  from the front side to prevent misalignment of the sealing member  35  to the front side. The seal holder  36  is fabricated separately from the male connector  20 , and is provided at a predetermined position after the sealing member  35  is placed on the periphery of the seal supporting part  31 . 
         [0028]    The seal holder  36  has an outer peripheral surface on which six guide projections  37  (second guide portions) are formed so as to be spaced apart from each other in a circumferential direction. The guide projections  37  of the seal holder  36  are also provided at positions similar to those of the guide projections  32  of the seal supporting part  31 . That is, each of both ends of the seal holder  36  in a major axial direction is provided with one guide projection  37 . These guide projections  37  are referred to as guide projections  37   x . The other four projections  37  are each provided to a boundary between a large curvature portion and a small curvature portion of the seal supporting part  31 . These guide projections are referred to as guide projections  37   y.    
         [0029]    The guide projections  37   x  engage with an inner peripheral surface of the sealing wall  6  when the male connector  20  is inserted into the connector placement window  5  of the case cover  4 , thereby regulating relative positions of the male connector  20  and the case cover  4  (the sealing wall  6 ) in a major axial direction. Similarly, the guide projections  37   y  engage with the inner peripheral surface of the sealing wall  6 , thereby regulating relative positions of the male connector  20  and the case cover  4  (the sealing wall  6 ) in a minor axial direction. 
         [0030]    The guide projections  37  ( 37   x  and  37   y ) are provided at the same positions as those of the corresponding guide projections  32  ( 32   x  and  32   y ) in the circumferential direction. In this manner, with the guide projections  32  and the guide projections  37  provided on both sides in a front-and-rear direction (a vertical direction in the drawings) across the sealing member  35  so as to be spaced apart from each other, relative positions of the male connector  20  and the case cover  4  (the sealing wall  6 ) in the front-and-rear direction (a z direction in  FIG. 3A ) are regulated when the male connector  20  is inserted into the connector placement window  5  of the case cover  4 . Note that while an example provided herein shows that the corresponding guide projections  32  and  37  are provided at the same position in the front-and-rear direction, the present invention is not meant to be restricted to this configuration and the projections  32  and  37  can be provided as being shifted from each other. 
         [0031]    Next, each receiving part  24  includes a holding wall  25  having holding holes  26  penetrating through the front and rear formed therein and a hood  27  standing from a circumferential edge of the holding wall  25  toward front. The contacts  22  are held by the holding wall  25  by being pressed into the holding holes  26 , and each of the contacts  22  has a side on a front side of the holding wall  25  accommodated in the hood  27  and a side on a rear side of the holding wall  25  accommodated inside the case cover  4 . 
         [0032]    As shown in  FIG. 2B , the holding wall  25  has a projecting part  28  projecting rearward. In this projecting part  28 , a screw hole  29  opening rearward is formed. The male connector  20  is fixed via each fixing seat  38  to the case  3  with a bolt (omitted in the drawings), and is assembled to the electronic device  1  with a bolt B penetrating through the circuit board  2  being screwed into the screw hole  29  of the projecting part  28 . 
         [0033]    When the male connector  20  is assembled to the electronic device  1 , the tip of the sealing member  35  of the male connector  20  is brought into intimate contact with the inner peripheral surface (a sealing surface) of the sealing wall  6  of the case cover  4  to seal a space between the case cover  4  and the male connector  20 , thereby ensuring a waterproof property inside the case cover  4 . 
         [0034]    In the present embodiment, a dimension (the height) of the sealing member  35  in the front-and-rear direction is set to be smaller than the height of the sealing wall  6 . This is to more reliably accommodate the sealing member  35  between the base  23  of the male connector  20  and the sealing wall  6  even if a misalignment of the case cover  4  in the front-and-rear (fitting) direction occurs. However, this is merely a preferable embodiment of the present invention. 
         [0035]    [Female Connector  40 ] Next, the female connector  40  to be mated with the male connector  20  includes, as shown in  FIG. 1  and  FIGS. 2A to 2C , a female housing  41  corresponding to the receiving parts  24  of the male connector  20 , female contacts  42  held by the female housing  41  to be electrically connected to the contacts  22  of the male connector  20 , a retainer  43  for cushioning a force at the time of insertion and removal of the connector, and lever engaging parts  44  provided on the periphery of the female housing  41  to prevent disconnection between the male connector  20  and the female connector  40  mated with each other. 
         [0036]    The female housing  41  has contact cavities  45  into which the contacts  22  of the male connector  20  are inserted. Into the contact cavities  45 , electric wires not shown connected to the contacts  42  are inserted. 
         [0037]    When the female connector  40  and the male connector  20  are connected together, the female housing  41  is accommodated in the accommodating parts  24 . A holding groove  47  is provided to an entire outer periphery of the female housing  41  on a rear end. In this holding groove  47 , the ring-shaped sealing member  46  is placed. 
         [0038]    When the female connector  40  and the male connector  20  are mated with each other, the sealing member  46  is brought into intimate contact with an inner peripheral surface of the hood  27  to seal a space between the male connector  20  and the female connector  40 . With such configuration, water can be prevented from entering from the space between the male connector  20  and the female connector  40 . 
         [0039]    Also, on the outer periphery of the female housing  41 , unshown rotating shafts  44   a  of the lever engaging parts  44  are formed. 
         [0040]    Each of the lever engaging parts  44  is rotated with a support shaft  48  formed on the outer periphery of the female housing  41  as an axis, and includes an engaging projection  49  engaging with an engaging projection  39  formed on an outer periphery of the hood  27 . According to this configuration, the male connector  20  and the female connector  40  are prevented from being removed from each other. 
         [0041]    The female housing  41  includes a skirt  50 . The skirt  50  is provided on a front end side of the female housing  41 , and has an accommodation space  51  (refer to  FIGS. 2B and 2C ) therein for accommodating a front end side of the male connector  20 . When the female connector  40  is mated with the male connector  20 , the base  23  of the male connector  20  is accommodated in the accommodation space  51  of the skirt  50 . That is, the skirt  50  covers the seal holder  36 , the sealing member  35  (the seal placing part  30 ), and the rubber supporting part  31 . The skirt  50  also covers the sealing wall  6  of the case cover  4  configuring the sealing part together with the sealing member  35 . 
         [0042]    To achieve the function described above, the accommodation space  51  of the skirt  50  has a width set to be larger than the outer shape of the sealing wall  6 . However, if a space between the sealing wall  6  and the skirt  50  is too large, the possibility of entrance of water is increased. On the other hand, if this space is too small, the skirt  50  interferes with the sealing wall  6  due to the dimensional tolerance to possibly cause a trouble in mating the female connector  40  with the male connector  20 . In consideration of these points, the dimension of the width of the skirt  50  can be set. Also, a dimension (a height) of the skirt  50  in a front-and-rear direction is preferably set so that a space is formed between a front end of the female connector  40  and the case cover  4  when the female connector  40  is mated with the male connector  20 . This is to secure complete mating between the female connector  40  and the male connector  20  by avoiding interference of the front end of the fitting skirt  50  with the case cover  4 . As a matter of course, the height of this space, that is, the height of the skirt  50 , should be determined in consideration of reduction in the possibility of entrance of water and misalignment of the connector. 
         [0043]    The procedure of assembling the male connector  20  to the electronic device  1  is described below with reference to  FIGS. 5A ,  5 B,  6 A, and  6 B. 
         [0044]    First, as shown in  FIG. 5A , the male connector  20  is assembled to the case  3  and the circuit board  2 . 
         [0045]    This assembling is performed as described above by fixing the male connector  20  to the case  3  with bolts (not shown) via the fixing seats  38  and screwing the bolt B penetrating through the circuit board  2  into the screw hole  29  of the projecting part  28 . 
         [0046]    Next, as shown in  FIG. 5B , the case cover  4  is placed. 
         [0047]    While the male connector  20  is being positioned relative to the connector placement window  5  of the case cover  4 , the case cover  4  is pressed toward the circuit board  2  to cause the male connector  20  to be inserted into the connector placement window  5 . During this course, the first guide projections  32  and the second guide projections  37  help ensure an appropriate intimate contact state of the sealing member  35  of the male connector  20  between these guide projections and the sealing wall  6  of the case cover  4 . 
         [0048]    That is, when the sealing wall  6  reaches the seal holder  36 , the guide projections  32  interfere with the inner periphery surface of the sealing wall  6 . Thus, the case cover  4  is not misaligned with respect to the male connector  20  as the guide projections  32  go beyond interference with the sealing wall  6 . For example, even if the case cover  4  is inserted into the male connector  20  as being tilted, as shown in  FIG. 4B , the guide projections  37  ( 32 ) engage with the inner peripheral surface of the sealing wall  6 , thereby allowing the male connector  20  to be inserted into the connector placement window  5  while regulating a further tilt of the case cover  4 . Therefore, as shown in  FIG. 6A , when the case cover  4  is pressed to reach the sealing member  35 , the sealing member  35  is brought into intimate contact with the inner peripheral surface of the sealing wall  6  over an entire area in a circumferential direction so as to obtain an intimate contact width necessary for ensuring a waterproof property. 
         [0049]    When the case cover  4  is further pressed, as shown in  FIG. 63 , the sealing wall  6  passes the sealing member  35  to reach the seal supporting part  31 . As a result, the guide projections  32  provided on the periphery of the seal supporting part  31  engage with the inner peripheral surface of the sealing wall  6 , thereby regulating the tilt of the case cover  4  in a manner similar to that described above. With the provision of the guide projections  32  and  37  across the sealing member  35  in a front-and-rear direction, this tilt of the case cover  4  is regulated not only in a planar direction (in an x direction and a y direction in  FIG. 3A ) but also in the front-and-rear direction (a z direction in  FIG. 3A ). In this manner, only by pressing the case cover  4  to the bottom, the necessary intimate contact width necessary for ensuring a waterproof property is provided to the sealing member  35 . According to such configuration as described above, the connector assembly  10  of the present embodiment can provide a high waterproof property between the case cover  4  and the male connector  20 . 
         [0050]    If the guide projections  32  and  37  are not provided, the case cover  4  is pressed to the bottom as the case cover  4  keeps being significantly tilted in the planar direction and the front-and-rear direction. Then, a partial contact occurs in which a portion with a too large intimate contact width and a portion with a too small intimate contact width are present in a mixed manner in the sealing member  35 . The portion with a too small intimate contact width has an insufficient waterproof property. In the portion with a too large intimate contact width, if the sealing member  35  and the sealing wall  6  too strongly interfere with each other, the sealing member  35  can be twisted or removed from the seal supporting part  31 . This also does harm to the waterproof property. 
         [0051]    After the case cover  4  is pressed to the bottom, the female connector  40  is caused to be mated with the male connector  20 . As a result, as shown in  FIG. 1 , the male connector  20  is covered with the female connector  40 . In particular, a portion sealed with the sealing member  35  and the sealing wall  6  is completely covered inside the skirt  50  of the female connector  40 , thereby preventing water from directly coming from the outside to the sealed portion. Also, the factor responsible for damage to the waterproof property is not directly provided from the outside to the sealing member  35 , thereby further improving the waterproof property of the sealed portion. 
         [0052]    In the connector assembly  10  described above, the provision of the guide projections  32  and  37  at six positions at the periphery of the seal support part  31  and the seal holder  36 , respectively, is suitable for guiding so that the center of the case cover  4  and the center of the male connector  20  match each other. However, the present invention allows the guide projections  32  and  37  to be place in a different arrangement. Even in this different arrangement, it should be assumed that the intimate contact width of the sealing member  35  be uniform in the planar direction and the front-and-rear direction. Also, a length (a dimension in the planar direction) of each of the guide projections  32  and  37  is not restrictive in the present invention. However, if the length is extremely too long, it may be difficult to ensure accuracy of a projection height over a length direction, and therefore the length is required to be set in consideration of this point. 
         [0053]    Furthermore, the example has been described in the above embodiment in which the sealing member  35  includes two ribs  35   a . This is because, even when a trouble such as a twist occurs in one rib  35   a , the waterproof property can be ensured if the other rib  35   a  remains intact. Therefore, the sealing member  35  including a plurality of the ribs  35   a  is preferable. 
         [0054]    As a matter of course, a sealing member for use in the present invention is not restricted to the one including ribs. For example, a rib sealing member or a grommet sealing member can be used. 
         [0055]    The waterproof connector of the present invention includes the guide portions on both sides across the sealing member, the guide portion guiding the housing to a position relative to the connector placement window. In accordance with such configuration, when the housing is inserted into the connector placement window, an appropriate intimate contact state can be provided to the sealing member without performing an extra operation. Therefore, the waterproof property in the sealing part can be stably ensured. 
         [0056]    In the waterproof connector of the present invention, the guide portions can include a first guide portion provided on one of the sides across the sealing member and a second guide portion provided on another one of the sides across the sealing member. Here, both of the first guide portion and the second guide portion can be formed integrally with the housing. Alternatively, the first guide portion can be formed integrally with the housing, and the second guide portion can be formed on a ring-shaped seal fixing member fixing the sealing member to the housing. 
         [0057]    In the waterproof connector of the present invention, a dimension of the sealing member in a mating direction of mating with the counterpart connector is preferably smaller than a dimension of the sealing wall in the mating direction. Even if the case cover is placed in the mating direction with misalignment, the sealing member can be brought into intimate contact with the sealing wall. 
         [0058]    In the waterproof connector of the present invention, the sealing member preferably includes a plurality of ribs projecting toward the sealing wall. This is because, even when a trouble such as a twist occurs in one rib, the waterproof property can be ensured if another rib remains intact. 
         [0059]    In the waterproof connector of the present invention, the plurality of guide portions are preferably placed so as to be spaced apart from each other in a circumferential direction of the housing. 
         [0060]    By freely adjusting the positions where the plurality of guide portions are to be provided, the housing can be guided to a more appropriate position of the seating wall. 
         [0061]    In the waterproof connector of the present invention, to improve the waterproof property, the counterpart connector preferably includes a skirt, and when the counterpart connector is connected to the waterproof connector, the sealing part is covered with the skirt. 
         [0062]    Furthermore, the present invention provides a mounting structure of a waterproof connector to be connected to a circuit board placed in a case and assembled to the case, the waterproof connector being any of the waterproof connectors described above and the case cover configuring a part of the case. 
         [0063]    According to the mounting structure of the waterproof connector of the present invention, an appropriate intimate contact state can be provided to the sealing member, thereby allowing an excellent waterproof property to be ensured inside the case. 
         [0064]    Still further, an embodiment of the present invention may provide a waterproof connector mounting method including the steps of connecting any of the waterproof connector described above to the circuit board and mounting the case cover including the sealing wall rising from the periphery of the connector placement window on the waterproof connector connected to the circuit board so that the waterproof connector is placed on the connector placement window. 
         [0065]    According to the waterproof connector mounting method of the present invention, only by assembling the case cover via the connector placement window to the case having the waterproof connector and the circuit board being fixed therein, an appropriate intimate contact state can be obtained in the sealing member, and therefore the mounting operation is easy. 
         [0066]    While the present invention has been described based on the embodiments, the structures described in the embodiments above can be selectively adopted or omitted or can be changed to another structure without deviating from the gist of the present invention.