Patent Publication Number: US-9407049-B2

Title: Device connector

Description:
BACKGROUND 
     1. Field of the Invention 
     The invention relates to a device connector. 
     2. Description of the Related Art 
     U.S. Pat. No. 8,011,977 discloses a device connector to be fixed to a case of a device. This device connector has a case-side housing to be fixed to the case of the device while being covered by a case-side shell made of metal, and a mating housing to be connected to the case-side housing while being covered by a mating shell made of metal. A bolt is used to fix the case-side shell and the case-side housing to the case. The mating housing then is fit lightly to the case-side housing. A connecting bolt on the mating shell then is tightened into the case-side shell to connect the mating housing and the case-side housing and also to fix the mating shell and the case-side shell in an electrically connected state. 
     The fixing bolt and the connecting bolt of the above described connector may be identical or similar. Thus, an operator may break the fixing bolt by erroneously further tightening the fixing bolt during the connecting operation or may cause rattling of the case-side housing by erroneously loosening the fixing bolt during a connector separating operation. 
     The invention was completed based on the above situation and an object thereof is to prevent an operator from erroneously accessing a fixing bolt. 
     SUMMARY OF THE INVENTION 
     The invention is directed to a device connector to be mounted and fixed to a case of a device. The device connector includes a case-side connector to be fixed to the case by fitting a tool to a bolt head on a fixing bolt and tightening the fixing bolt into the case. A mating connector is to be connected to the case-side connector and fixed to the case by tightening a connecting bolt into the case with the mating connector mounted on the case-side connector. An access prohibiting portion is provided on the mating connector and is configured to prohibit the tool from being fit to the bolt head by being arranged near the bolt head when the mating connector is mounted on the case-side connector. Thus, the tool cannot be fit to the fixing bolt and an operator cannot erroneously access the fixing bolt. Accordingly, the fixing bolt will not be broken by tightening when connecting the mating connector and rattling of the device connector will not be caused by erroneously loosening the fixing bolt when separating the connectors. 
     The access prohibiting portion may be arranged behind the fixing bolt in a tightening direction of the fixing bolt when the mating connector is mounted on the case-side connector. Accordingly, the tool, such as an impact wrench, cannot be fit to the bolt head from behind. 
     The mating connector may have a metal shield shell that is fixed and electrically connected to the case. The access prohibiting portion may be integral to the shield shell and can be formed while forming the metal shield shell, for example, by die cast molding. The metal access prohibiting portion is stronger than one formed from resin and will be difficult to break even if contacted by the tool or another member. 
     The access prohibiting portion may include a plate-like projection projecting from an outer wall of the shield shell and a reinforcing rib may be connected integrally to the shield shell and the projection. 
     Enhanced strength could be achieved by thickening the projecting piece when forming the access prohibiting portion together with the shield shell by die cast molding. However, air bubbles may be produced in the thick projection and cracks may be formed in the projection. However, the reinforcing rib enhances the strength of the access prohibiting portion without increasing the thickness of the projection. 
     The access prohibiting portion may have a size as to conceal the rear surface of the bolt head from behind in a tightening direction. Accordingly, the bolt head can be made invisible from behind in the tightening direction in a state where the mating connector is mounted on the case-side connector, thereby further preventing the operator from accessing the fixing bolt. 
     The access prohibiting portion may be a box for covering the entire bolt head from behind in a tightening direction. Thus, the bolt head of the fixing bolt is invisible to the operator from behind and from a lateral side when the mating connector is mounted on the case-side connector. Accordingly, the operator cannot access the fixing bolt. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a front view of a device connector in a first embodiment. 
         FIG. 2  is a plan view of the device connector. 
         FIG. 3  is a section along A-A of  FIG. 2 . 
         FIG. 4  is a section along B-B of  FIG. 2 . 
         FIG. 5  is a front view showing a state before a wire-side connector and a case-side connector are connected. 
         FIG. 6  is a plan view showing a state where the case-side connector is fixed to a case. 
         FIG. 7  is a plan view of a device connector in a second embodiment. 
         FIG. 8  is a section, equivalent to  FIG. 4 , in the second embodiment. 
         FIG. 9  is a front view of a device connector in a third embodiment. 
         FIG. 10  is a section, equivalent to  FIG. 4 , in the third embodiment. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     A device connector in accordance with a first embodiment of the invention is identified by the numeral  10  in  FIGS. 1 to 6 . As shown in  FIGS. 1 and 4 , the device connector  10  includes a case-side connector  20  and a wire-side connector  30 . The case-side connector  20  is to be fixed and fit into a mounting hole C 1  in a case C. The wire-side connector  30  is provided on ends of wires W and is connected to the case-side connector  20 . In the following description, forward and backward directions are based on a mounting direction of the device connector  10  onto the case C in  FIG. 4 , and a side to be mounted on the case C is referred to as a front side. 
     The case C of the device is made of electrical conductive metal and the mounting hole C 1  enables the inside and outside of the case C to communicate. A fixing bolt hole H 1  and a connecting bolt hole H 2  are formed on the case C near the mounting hole C 1 . A fixing bolt  50  can be tightened into the fixing bolt hole H 1  for fixing the case-side connector  20  to the case C, as shown in  FIG. 4 . The fixing bolt  50  has a bolt head  51  on one end and a shaft  52  extends in an axial direction from an axial central part of the bolt head  51 . A screw thread is formed on the outer periphery of the shaft  52  and the shaft  52  is tightened into the fixing bolt hole H 1  by rotating the bolt head  51  by a tool T. A connecting bolt BT can be tightened into the connecting bolt hole H 2  for connecting the wire-side connector  30  and the case-side connector  20 , as shown in  FIG. 3 . The connecting bolt BT has the same shape as the fixing bolt  50  and is tightened into the connecting bolt hole H 2  by the tool T similarly to the fixing bolt  50 . 
     The case-side connector  20  includes a case-side housing  21  made of synthetic resin and two male terminals  22  are accommodated in this case-side housing  21 , as shown in  FIG. 4 . The male terminals  22  are connected to an unillustrated internal wiring of the device. 
     The case-side housing  21  is long in forward and backward directions and a laterally projecting fixing piece  23  is provided on the outer surface of the case-side housing  21 . A metal collar  24  is formed integrally to the fixing piece  23 . The metal collar  24  and the case C are bolted firmly in a state where the fixing bolt  50 , the metal collar  24  and the case C are held directly in contact by inserting the fixing bolt  50  into the metal collar  24  and rotating the bolt head  51  of the fixing bolt  50  by the tool T to tighten the shaft  52  of the fixing bolt  50  into the fixing bolt hole H 1  of the case C. In this way, the case-side connector  20  is mounted and fixed to the case without rattling. 
     A case-side fitting  25  is formed in the case-side housing  21  before the fixing piece  23  and can be fit into the mounting hole C 1  of the case C. A connector fitting  26  is behind the fixing piece  23  and can be fit to the wire-side connector  30 . 
     A case-side seal ring R 1  is mounted on the outer peripheral surface of the case-side fitting  25 . The case-side seal ring R 1  seals between the outer peripheral surface of the case-side fitting  25  and the inner peripheral surface of the mounting hole C 1  to prevent water from entering the case C when the case-side fitting  25  is fit into the mounting hole C 1  of the case C. Further, a connector-side seal ring R 2  is mounted on the outer peripheral surface of the connector fitting  26 . 
     The wire-side connector  30  has a wire-side housing  31  and a shield shell  40  for covering the wire-side housing  31 , as shown in  FIGS. 3 and 4 . The wire-side housing  31  is long in forward and backward directions and is made of synthetic resin. 
     A front part of the wire-side housing  31  can fit into the connector fitting  26  of the case-side housing  21 . Two female terminals  32  are held in the wire-side housing  31 . Each female terminal  32  includes a connecting tube  33  that is connectable to the male terminal  22  of the case-side connector  20  and a barrel  34  behind the connecting tube  33  for connection to the end of the wire W. The connectors  20 ,  30  are connected when the wire-side housing  31  is fit into the connector fitting  26  so that the male terminals  22  and the connecting tubes  33  of the female terminals  32  are connected electrically. 
     A seal ring R 3  is mounted on the outer peripheral surface of the wire-side housing  31  and seals between the inner peripheral surface of the connector fitting  26  and the outer peripheral surface of the wire-side housing  31  to prevent water from entering into the housings  21 ,  31  when the wire-side housing  31  is fitted into the connector fitting  26 . 
     The shield shell  40  is made of electrically conductive metal and formed to have a substantially uniform thickness, for example, by aluminum die casting. The shield shell  40  is substantially tubular and is held on the wire-side housing  31  by being locked by a locking portion (not shown) on the wire-side housing  31 . The case-side seal ring R 2  of the case-side housing  21  closely contacts the inner peripheral surface of the shield shell  40  over the entire circumference to prevent water from entering into the shield shell  40  through a clearance between the two connectors  20 ,  30  when the connectors  20 ,  30  are connected. A front end part of the shield shell  40  contacts a peripheral part of the mounting hole C 1  of the case C from behind to be electrically connected as the two connectors  20 ,  30  are connected. In this way, the two housings  21 ,  31  are shielded entirely. 
     A pedestal  41  projects laterally on the front part of the shield shell  40 , as shown in  FIGS. 2 and 3 . A bolt insertion hole  42  is formed in the pedestal  41  and can receive the connecting bolt BT. An unillustrated E-ring is mounted after the connecting bolt BT is inserted into the bolt insertion hole  42  to hold the connecting bolt BT on the pedestal  41 . In connecting the two connectors  20 ,  30 , the wire-side housing  31  is fit lightly fitted into the connector fitting  26  and the connecting bolt BT is tightened into the connecting bolt hole H 2  to bring the pedestal  41  closer to the case C and to bring the two connectors  20 ,  30  to a properly connected state. 
     A hinged bolt cap CP is mounted between the pedestal portion  41  and the connecting bolt BT and is mountable on the connecting bolt BT from behind after the two connectors  20 ,  30  are connected. Although the bolt cap CP is mounted on the connecting bolt BT in this embodiment, it is not always necessary to mount a bolt cap on the connecting bolt BT and no bolt cap is shown in  FIG. 2 . 
     As shown in  FIGS. 1, 2 and 4 , an access prohibiting portion  43  is provided on the outer surface of the shield shell  40 . The access prohibiting portion  43  is in proximity to the fixing bolt  50  when the wire-side connector  30  is mounted on the case-side connector  20  and is behind fixing bolt  50  in a tightening direction thereof. The access prohibiting portion  43  is more proximate to the fixing bolt  50  when the two connectors  20 ,  30  are connected properly. 
     The access prohibiting portion  43  is formed integrally to the shield shell  40  when forming the shield shell  40  by aluminum die casting. Further, the access prohibiting portion  43  includes a projection  44  in the form of a flat plate projecting laterally from the outer surface of the shield shell  40 . A front surface  44 A of the projection  44  faces a rear surface  51 A of the bolt head  51  of the fixing bolt  50  in forward and backward directions, and the thickness of the projection  44  is substantially equal to that of the shield shell  40 . A clearance capable of taking up tolerances is provided between the front surface  44 A of the projection  44  and the rear surface  51 A of the bolt head  51 , considering manufacturing tolerances and assembling tolerances of the shield shell  40 , the fixing bolt  40  and the like, in this embodiment, the front surface  44 A of the projection  44  and the rear surface  51 A of the bolt head  51  may be held in contact without being limited to this. A reinforcing rib  45  is provided unitarily on the rear surface of the projecting piece  44  to enhance the strength of the projection  44 . 
     A projection could be thickened to increase the strength of an access prohibiting portion. However, a thick projection on an access prohibiting portion formed by die cast molding could have air bubbles that may cause cracks and the like in the projecting piece in. The reinforcing rib  45  increases the strength of the access prohibiting portion  43  without thickening the projection  44  and hence avoids the formation of cracks. 
     The projecting end of the projection  44  is rounded and projects up to substantially the same position as the axial center of the fixing bolt  50 . Thus, while the wire-side connector  30  is mounted on the case-side connector  20  to connect the two connectors  20 ,  30 , the projecting piece  44  and a part of the bolt head  51  of the fixing bolt  50  are proximate to each other and overlap in forward and backward directions when the device connector  10  is viewed from behind (see  FIG. 2 ). This prevents the tool T, such as an impact wrench, from being fit to the bolt head  51  of the fixing bolt  50  from behind. 
     The device connector  10  of this embodiment is assembled by initially inserting the case-side connector  20  into the mounting hole C 1  of the case C to a proper position. The fixing bolt  50  then is inserted into the metal collar  24  of the fixing piece  23  of the case-side connector  20  and the bolt head  51  of the fixing bolt  50  is rotated by the tool T from behind. Accordingly, the shaft  52  of the fixing bolt  50  is tightened into the fixing bolt hole H 1  of the case C and the case-side connector  20  is mounted and fixed to the case without rattling, as shown in  FIG. 5 . Nothing is arranged behind the fixing bolt  50  when fixing the case-side connector  20  to the case C, as shown in  FIGS. 5 and 6 . As a result, the tool T such as an impact wrench easily can be fit to the bolt head  51  of the fixing bolt  50 . 
     The wire-side housing  31  then is fit lightly to the case-side housing  21  by hand and the connecting bolt BT is tightened into the connecting bolt hole H 2  using the tool T so that the two connectors  20 ,  30  are connected, as shown in  FIGS. 1 and 4 . The connecting bolt BT and the fixing bolt  50  are shaped identically. Thus, an operator attempting to fit the tool T to the connecting bolt BT may erroneously fit the tool T to the fixing bolt  50  and further tighten the fixing bolt  50 . However, the access prohibiting portion  43  of the shield shell  40  is near the fixing bolt  50  when the wire-side housing  31  is fit lightly to the case-side housing  21 . Further, the access prohibiting portion  43  also is near the fixing bolt  50  when the two connectors  20 ,  30  are connected properly, as shown in  FIGS. 1 and 4 . Therefore, the tool T, such as an impact wrench, cannot be fit to the bolt head  51  of the fixing bolt  50  from behind and the fixing bolt  50  will not be broken by being erroneously further tightened by the operator during a connecting operation. 
     The wire-side connector  30  can be separated from the case-side connector  20  by fitting the tool T, such as an impact wrench, to the connecting bolt BT and loosening the connecting bolt BT so that the wire-side housing  31  gradually separates from the case-side housing  21 . The tool T may be fittable to both the connecting bolt BT and the fixing bolt  50 . Hence, there is a concern that the operator may erroneously loosen the fixing bolt  50  to cause rattling of the case-side connector  20 . Thus, connection reliability between the male terminals  22  and the female terminals  32  might not be ensured when the two connectors  20 ,  30  are connected again. 
     However, according to this embodiment, the access prohibiting portion  43  of the shield shell  40  is behind and in proximity to the bolt head  51  of the fixing bolt  50  when the connectors  20 ,  30  are connected properly, as shown in  FIGS. 1 and 4 . Thus, the tool T such as an impact wrench cannot be fit to the bolt head  51  of the fixing bolt  50  from behind and the operator cannot erroneously loosen the fixing bolt  50  to cause rattling of the case-side connector  20 . 
     As described above, according to this embodiment, the access prohibiting portion  43  can be arranged behind and in proximity to the bolt head  51  of the fixing bolt  50  when the wire-side connector  30  is mounted on the case-side connector  20 . Thus, an operator cannot erroneously access the fixing bolt  50  when connecting or separating the wire-side connector  30 . Accordingly, the fixing bolt  50  will not be broken during the connecting operation and the case-side connector  20  will not rattle due to loosening the fixing bolt  50  during the separating operation. 
     The access prohibiting portion  43  is formed unitarily with the metal shield shell  40  and therefore is stronger than an access prohibiting portion  43  made of resin or the like. Thus, the access prohibiting portion  43  is difficult to break even if contacted by a tool T, such as an impact wrench, or another member. 
     A device connector in accordance with a second embodiment of the invention is identified by the numeral  11  in  FIGS. 7 and 8 . The device connector  11  of the second embodiment differs from the first embodiment with respect to the shape of the access prohibiting portion. Parts of the second embodiment that are the same as the first embodiment are identified by the same reference numbers, but are not described again. 
     An of a shield shell  140  in the device connector  11  of the second embodiment has a shield shell  140  with an access prohibiting portion  143  that projects laterally a large amount, as shown in  FIGS. 7 and 8 , while having the same height as the access prohibiting portion  43  of the first embodiment. Specifically, a projecting piece  144  and a reinforcing rib  145  of the access prohibiting portion  143  project laterally from a lateral end part of a bolt head  51  of a fixing bolt  50 , and a rear surface  51 A of the bolt head  51  is completely concealed by the projecting piece  144  of the access prohibiting portion  143  when a wire-side connector  30  is mounted on a case-side connector  20  and the bolt head  51  of the fixing bolt  50  is viewed from behind. Specifically, the bolt head  51  of the fixing bolt  50  cannot be seen from behind when the wire-side connector  30  is mounted on the case-side connector  20 , as shown in  FIG. 7 . This can further prevent erroneous access to the fixing bolt  50  by an operator. 
     A device connector in accordance with a third embodiment of the invention is identified by the number  12  in  FIGS. 9 and 10 . The device connector  12  of the third embodiment differs from the first embodiment with respect to the shape of the access prohibiting portion. Parts of the third embodiment that are the same as the first embodiment are identified by the same reference numbers, but are not described again 
     The device connector  12  of the third embodiment has a shield shell  240  with an access prohibiting portion  243  in the form of a box that is open forward, as shown in  FIGS. 9 and 10 . The access prohibiting portion  143  completely covers the entire bolt head  51  of the fixing bolt  50  when a wire-side connector  30  and a case-side connector  20  are connected properly. Specifically, the bolt head  51  of the fixing bolt  50  is invisible from behind and from a lateral side as shown in  FIG. 9  when the wire-side connector  30  is mounted on the case-side connector  20 , thereby further preventing erroneous access to the fixing bolt  50 . 
     The invention is not limited to the above described embodiments. For example, the following embodiments also are included in the scope of the invention. 
     The access prohibiting portion  43 ,  143  is arranged behind and in proximity to the bolt head  51  of the fixing bolt  50  in the first and second embodiments and the bolt head  51  is covered completely in the third embodiment. However, an access prohibiting portion may be arranged lateral to and in proximity to the bolt head  51  of the fixing bolt  50  or the bolt head  51  of the fixing bolt  50  may be covered by the access prohibiting portion together with the fixing piece  23 . 
     The shield shell  40 ,  140 ,  240  is provided with the access prohibiting portion  43 ,  143 ,  243  in the above embodiments. However, the wire-side housing may be provided with an access prohibiting portion. 
     Although the case-side connector  20  is fixed to the case C by fixing the case-side housing  21  to the case C in the above embodiments, the present invention is not limited to such a mode. For example, the case-side connector may be provided with a case-side shield shell and fixed to the case by fixing the case-side shield shell to the case. 
     Although the projecting piece  44 ,  144  projects from the outer surface of the shield shell  40  up to the axial center of the bolt head  51  or the vicinity of the lateral end part of the bolt head  51  in the first and second embodiments. However, a projecting amount of the projecting piece from the shield shell may be appropriately determined in consideration of the size, the insertion angle and the like of the tool to be fitted to the bolt head.