Patent Publication Number: US-9899755-B2

Title: Connector and connection structure

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of the filing date under 35 U.S.C. § 119(a)-(d) of Japanese Patent Application No. 2016-009487, filed on Jan. 21, 2016. 
     FIELD OF THE INVENTION 
     The present invention relates to a connector, and more particularly, to a connector movable with respect to a circuit board. 
     BACKGROUND 
     A connector mounted to a circuit board and mating with a mating connector to form an electrical connection is known in the art. For example, a connector mounted to an encoder circuit board of a servo motor relays power for activating the encoder circuit and an output signal indicting a rotation state of the motor. 
     Japanese Patent Application Laid Open No. 2010-118314 shows an electric connector mounted to a circuit board and having a mechanism enabling motion of the connector with respect to the circuit board. The electric connector can be moved in a horizontal direction and a depth direction with respect to the circuit board. 
     When a mating connector, however, attempts to mate in the depth direction with the connector of JP 2010-118314A, the connector moves in the depth direction. Since the connector is moved in a direction away from the mating connector, there is a possibility that a semi-mated state occurs between the both connectors. Further, the connector described in JP 2010-118314A cannot move in a direction approximately perpendicular to the mating depth direction. As a result, when a mating connector retained, for example, by a machine is mated with the connector, the connector cannot adjust position perpendicular to the mating direction, and there is a possibility that even when a retaining position of the mating connector only slightly deviates from a normal position, mating cannot be performed. 
     SUMMARY 
     An object of the invention, among others, is to provide a connector which has a high tolerance to positional deviation of a mating connector and can securely mate with the mating connector. The connector comprises a contact having a resilient contact portion, a housing retaining the contact and having a pair of restricting projections, and a retainer having a resilient retainer portion. The retainer is disposed between the pair of restricting projections and retains the housing on the circuit board. The pair of restricting projections restricts movement between the housing and the circuit board in the mating direction and the resilient contact portion and the resilient retainer portion permit movement between the housing and the circuit board in a plurality of directions perpendicular to the mating direction. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will now be described by way of example with reference to the accompanying Figures, of which: 
         FIG. 1  is a front perspective view of a connector according to the present invention; 
         FIG. 2  is a back perspective view of the connector of  FIG. 1 ; 
         FIG. 3  is a front view of the connector of  FIG. 1 ; 
         FIG. 4  is a back view of the connector of  FIG. 1 ; 
         FIG. 5  is a side view of the connector of  FIG. 1 ; 
         FIG. 6A  is a side view of a contact of the connector of  FIG. 1 ; 
         FIG. 6B  is a plan view of the contact of  FIG. 6A ; 
         FIG. 7  is a sectional view of the connector of  FIG. 1  taken along line  7 - 7  of  FIG. 3 ; 
         FIG. 8A  is a side view of a retainer of the connector of  FIG. 1 ; 
         FIG. 8B  is a front view of the retainer of  FIG. 8A ; 
         FIG. 9  is a perspective view of a servo motor; 
         FIG. 10  is a side view of a mating connector; 
         FIG. 11  is a side view of a connection between the mating connector of  FIG. 10  and the connector of  FIG. 1 ; 
         FIG. 12  is a perspective view of the connection of  FIG. 11 ; and 
         FIG. 13  is a side view of a servo motor according to another embodiment. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENT(S) 
     Embodiments of the present invention will be described hereinafter in detail with reference to the attached drawings, wherein like reference numerals refer to the like elements. The present invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein; rather, these embodiments are provided so that the disclosure will be thorough and complete, and will fully convey the concept of the invention to those skilled in the art. 
     A connector C according to the invention is shown in  FIG. 1 . The connector C shown in  FIG. 1  is a surface-mounted type of connector, and it is mounted on a surface of a circuit board B by soldering. The connector C electrically connects the circuit board B and a cable connected to a mating connector M by mating with the mating connector M. 
     The connector C is a right-angle type connector, and it mates with the mating connector M in a direction extending along the circuit board B. In the connector C, the direction of mating with the mating connector M is referred to as a mating direction (or a front and back direction) Y. In the mating direction Y, a mating side of the connector C mating with the mating connector M is referred to as a front side, while an opposite side thereto is referred to as a back side. Further, a direction perpendicular to the mating direction Y and extending along the circuit board B is referred to as a left and right direction X. Further, a direction perpendicular to both the mating direction Y and the left and right direction, namely, a direction approximately perpendicular to the circuit board B is referred to as a perpendicular direction (a vertical direction) Z. 
     The connector C shown in  FIGS. 1-5  has eight contacts  1  ( 1 A to  1 H), a housing  2  retaining these contacts  1 , and two retainers  3 A and  3 B. The housing  2  has a rectangular mating recess  21  opened to the front side. A mating contact MC achieves mating such that it enters in the mating recess  21  of the housing  2 . The contacts  1 A to  1 H contact with the mating contacts MC in a state where the connector C and the mating connector M have mated with each other. 
     The contacts  1 A to  1 H are arranged on a bottom of the mating recess  21  of the housing  2  in a two-level fashion along the perpendicular direction (the vertical direction) Z. The contacts  1 A to  1 H project within the mating recess  21  toward the mating direction Y, respectively. Four contacts  1 A to  1 D of the contacts  1 A to  1 H are arranged at an upper level relatively apart from the circuit board B and have configurations similar to one another. Further, four contacts  1 E to  1 H are arranged at a lower level relatively close to the circuit board B and have configurations similar to one another. 
     One representative upper level contact  1 A and one representative lower level contact  1 E are shown in  FIG. 6 . Each contact  1 A,  1 E has a contact end  11 , a board connection end  12 , a press-fitting contact portion  13 , and a resilient contact portion  14 . The contacts  1 A and  1 E are formed by stamping and bending of a conductive metal plate having elasticity. Therefore, the contact end  11 , the board connection end  12 , the press-fitting contact portion  13 , and the resilient contact portion  14  are formed integrally. 
     The contact end  11  makes contact with the mating contact MC. The contact end  11  extends in the mating direction Y. As shown in  FIG. 7 , the contact end  11  projects from a bottom of the mating recess  21  in the mating direction Y. The board connection end  12  is a portion connected to the circuit board B by soldering. 
     The press-fitting contact portion  13  is disposed between the contact end  11  and the board connection end  12 . The press-fitting contact portion  13  is disposed on a back side of the contact end  11  and is wider than the contact end  11 . The press-fitting contact portion  13  is press-fitted into the housing  2  to be retained and fixed to the housing  2 . 
     The resilient contact portion  14 , as shown in  FIG. 6 , is disposed between the press-fitting contact portion  13  and the board connection end  12 . The contact  1 A at the upper level and the contact  1 E at the lower level have a different length in the perpendicular direction Z of the resilient contact portion  14 . 
     The board connection end  12  of the contact  1 A at the upper level and the board connection end  12  of the contact  1 E at the lower level are connected to the common circuit board B, as shown in  FIG. 1 , and the respective contact end portions  11  are arranged at different levels from each other in the perpendicular direction Z. The resilient contact portion  14  elastically deforms to allow a relative movement between the housing  2  and the board connection end  12 . 
     The resilient contact portion  14  has a first curved portion  14   a  and a second curved portion  14   b  as shown in  FIG. 6 . The first curved portion  14   a  extends in a direction away from the mating connector M in the mating direction Y, namely, toward the back side, and next turns to extends in a direction towards the mating connector M, namely, toward the front side. The second curved portion  14   b  is reversed from a distal end of the first curved portion  14   a . In the shown embodiment, the first curved portion  14   a  has a U shape connected to the press-fitting contact portion  13  and opened toward the front side, and the second curved portion  14   b  has a U shape connected to the first curved portion  14   a  and opened toward the back side. The resilient contact portion  14  thus has an S shape obtained by combining the above two U shapes. Since the resilient contact portion  14  has the first curved portion  14   a  and the second curved portion  14   b , a structure allowing a relative movement of the housing  2  in the perpendicular direction Z is made small in size. Further, since the resilient contact portion  14  has an S shape as a whole, even if the contact end  11  moves in the perpendicular direction Z due to an elastic deformation, an attitude of the contact end  11  facing in the mating direction Y is maintained. 
     The retainers  3 A,  3 B are identical in the embodiment shown in  FIG. 1 . As shown in  FIG. 8 , the retainer  3 A has a board fixing portion  31 , a press-fitting retainer portion  32 , and a resilient retainer portion  33 . The retainer  3 A is formed by performing stamping to a conductive metal plate having an elasticity and next performing bending to a portion of the board fixing portion  31 . Therefore, the board fixing portion  31 , the press-fitting retainer portion  32 , and the resilient retainer portion  33  are formed integrally. 
     The board fixing portion  31  is connected to the circuit board B, as shown in  FIG. 1 , by soldering. The press-fitting retainer portion  32  is press-fitted into the housing  2  to be fixed to the housing  2 . The resilient retainer portion  33  is disposed between the board fixing portion  31  and the press-fitting retainer portion  32 . The resilient retainer portion  33  elastically deforms to allow a relative movement between the housing  2  fixing the press-fitting retainer portion  32  and the board fixing portion  31 . 
     The resilient retainer portion  33  has a curved portion  33   a  and a straight portion  33   b . The curved portion  33   a  extends in a direction away from the mating connector M in the mating direction Y, namely, toward the rear side and then turns to extend in a direction toward the mating connector M, namely, toward the front side. The curved portion  33   a  has a U shape opened toward the front side. The straight portion  33   b  extends straight from the curved portion  33   a  to the board fixing portion  31  in the perpendicular direction Z. 
     The housing  2  shown in  FIGS. 1-4  is a molded product made of insulating resin material. The housing  2  has an approximately parallelepiped outer shape, and the mating recess  21  is opened to a front side face of the housing  2  facing the mating connector M. A slope  21   a  spreading toward the outside is formed at a peripheral edge of the opening portion of the mating recess  21 . Restricting projections  22 - 25  projecting in the left and right direction X are provided on respective side faces  2   a ,  2   b  of the housing  2  in the left and right direction in a paired manner. The restricting projections  22 ,  24  of the restricting projections of the respective pairs provided on the front side also serve as retaining portions of the retainers  3 A,  3 B, and the press-fitting retainer portions  32  of the retaining portions  3 A,  3 B are press-fitted therein. As shown in  FIG. 5 , the retainers  3 A,  3 B are retained by the housing  2  such that the board fixing portion  31  projects from the housing  2  downward, namely, toward the circuit board B. Further, as explained previously, the retainers  3 A,  3 B are formed by performing stamping to a metal plate, and the fitting elastically deformable portions  33  of the retainers  3 A,  3 B are arranged such that their plate faces face in the left and right direction X. Further, as shown in  FIG. 4 , clearances are provided between the retainers  3 A,  3 B and the side faces  2   a ,  2   b  of the housing  2 , respectively. 
     The pair of restricting projections  22 ,  23  shown in  FIG. 5  are provided at positions sandwiching a portion of the retainer  3 A between the press-fitting retainer portion  32  and the board fixing portion  31  from both side in the mating direction Y. In more detail, the pair of restricting projections  22 ,  23  are provided at positions of sandwiching the straight portion  33   b  of the resilient retainer portion  33  of the retainer  3 A extending in the perpendicular direction Z from both sides in the mating direction Y. The above-described positional relationship also applies to an arrangement relationship between the pair of restricting projections  24 ,  25  provided on the side face  2   b  opposed to the side face  2   a  shown in  FIG. 5 , and the retainer  3 B. 
     The housing  2  of the connector C of the present embodiment is supported by the circuit board B via the retainers  3 A,  3 B having the resilient retainer portions  33 . Therefore, according to elastic deformations of the resilient retainer  33 , the housing  2  can move relative to the circuit board B in the left and right direction X and the perpendicular direction Z. The resilient retainer portions  33  warp so that the housing  2  can move in the left and right direction. Further, the curved portions  33   a  of the resilient retainer portions  33  deform such that the curves are opened or closed, so that the housing  2  can move in the perpendicular direction Z. Therefore, even if the position of the mating connector M mating with the connector C deviates from a target position in the left and right direction X and the perpendicular direction Z which are perpendicular to the mating direction Y, the housing  2  of the connector C can follow the deviation. Further, even if the position of the mating connector M deviates in the left and right direction and the perpendicular direction prior to contact of the mating connector M with the connector C, the mating connector M is guided by the slope  21   a  provided on the opening peripheral edge of the mating recess  21 , so that positioning is performed. Further, the first curved portions  14   a  of the resilient contact portions  14  have the same shape as that of the curved portion  33   a  of the resilient retainer portion  33 . Therefore, the contact ends  11  supported by the housing  2  via the press-fitting contact portion  13  can also follow movement of the housing  2 . 
     Deformations of the retainers  3 A,  3 B in the mating direction Y are suppressed by the restricting projections  22 - 25 . That is, the relative movement of the retainers  3 A,  3 B between the housing  2  fixing the housing press-fitting retainer portions  32  and the board fixing portion  31  in the mating direction Y is restricted. Therefore, when the mating connector MC mates with the connector C, movement of the connector C in the mating direction Y is restricted. Therefore, even when the mating connector MC is caused to mate with the connector C, for example, by using a manufacturing machine, secure mating is achieved without resulting in a semi-mated state. 
     An application example of the above-described connector C will now be described in greater detail. 
     A servo motor S is shown in  FIG. 9  and has a motor  4  receiving power to be driven and an encoder  5  detecting a rotation state of the motor  4 . The motor  4  is provided with a rotation shaft  41 , a motor cover  42 , and a motor connector  43 . The motor cover  42  has a side face portion  421  surrounding the rotation shaft  421 . The motor connector  43  is a connector for supply power to the motor  4 . The motor connector  43  is arranged inside the motor cover  42 , but it is exposed to the outside via a hole  421   h  provided in the side face portion  421 . 
     The motor  4  and the encoder  5  are arranged in an extension direction of the rotation shaft  41  so as to align with each other. The encoder  5  is provided with a circuit board  51 , an encoder cover  52 , and an encoder connector C. The circuit board  51  converts a rotation state of the rotation shaft  41  to an electric signal. The circuit board  51  is arranged perpendicularly to the extension direction of the rotation shaft  41 . The encoder connector C is attached to the circuit board  51 . The encoder cover  52  covers the circuit board  51 . The encoder cover  52  has a side face portion  521  spreading continuously to the side face portion  421  of the motor cover  42 . The encoder connector C is arranged inside the encoder cover  52 , but it is exposed to the outside via a hole  521   h  provided in the side face portion  521 . The motor connector  43  and the encoder connector C are arranged in the extension direction of the rotation shaft  41  so as align with each other. 
     The encoder connector C is provided with the same configuration as that of the connector C which has been explained with reference to  FIG. 1-8 . Therefore, the encoder connector C and the connector C are represented by the same reference sign. Further, the extension direction of the rotation shaft  41 , namely, the perpendicular direction to the circuit board  1 , is referred to as the perpendicular direction Z so as to conform with the direction of the connector C shown in  FIGS. 1-8 . In addition, the direction where the encoder connector C faces the hole  521   h  of the side face portion  521  is referred to as the mating direction Y, and the perpendicular direction perpendicular to both of the perpendicular direction Z and the mating direction Y is referred to as the left and right direction X. 
     The mating connector M 2 , as shown in  FIGS. 10-12 , is one for relaying an electric signal from the encoder  5  to a control device of the motor  4 , and terminates a cable  60  extending from the control device. In a connection structure of the mating connector MC 2  and the connector C, the mating connector M 2  has eight mating contact MC 2 . The mating connector M 2  mates with the encoder connector C through the hole  521   h  of the encoder cover, so that the contacts MC 2  make contact with the contacts  1 A to  1 H of the encoder connector C, respectively. An electric signal outputted from the circuit board  51  is relayed at the encoder connector C to be transmitted to the control device. In the servo motor S of the present embodiment, the encoder connector C is attached in the vicinity of an edge of the circuit board  51 . Further, the encoder connector C is attached such that the mating recess  21  (see  FIG. 1 ) has the same direction as that of the edge of the circuit board  51 . That is, the mating recess  21  is opened toward the mating direction Y extending along the circuit board  51 . Further, the hole  521   h  of the encoder cover is formed at a position facing the mating recess  21  of the encoder connector C. 
     In another embodiment shown in  FIG. 13 , a relay cable  9  is used to relay an electric signal outputted from a circuit board to the mating connector M 2 . One end of the relay cable  9  is provided with a first connector  91  connected to the mating connector M 2 , and the other end thereof is provided with a second connector  92  connected to a circuit board  81 . An assembling step of the servo motor of the reference example is performed in the following manner: The first connector  91  is first attached to an encoder cover  82  which has been separated from the servo motor. Next, the second connector  92  of the relay cable  9  is pulled out from the inside of the encoder cover  82  and the second connector  92  is connected to the connector  93  mounted on the circuit board  81 . Next, the encoder cover  82  is attached so as to cover the circuit board. The above-described assembling step is complicated, and it is difficult to mechanize working inside the encoder cover  82 . 
     In the servo motor S having the encoder connector C of  FIGS. 9-11 , a relay between the circuit board  51  and the mating connector M 2  can be performed by using only one encoder connector C. Further, since no cable exists in the encoder cover  52 , the working is completed in the assembling step by only connecting the encoder connector C to the circuit board  51  like other parts through soldering in advance and attaching the encoder cover  52  so as to cover the encoder cover  51 . Therefore, mechanization of assembling becomes easy. In addition, the relay cable and the connectors at both ends thereof can be reduced. 
     Further, in the servo motor S of the present embodiment, the encoder connector C can move in the perpendicular direction Z and the left and right direction X according to elastic deformations of the fitting elastically deformable portions  33  of the retainers  3 A,  3 B. In the servo motor S, the position of the mating recess  21  of the encoder connector C and the position of the hole  521   h  of the encoder cover  52  may deviate from target positions due to a deviation of the mounting position of the encoder connector C on the circuit board  51  or a deviation of the encoder cover  52 . In the servo motor S of the present embodiment, since the encoder connector C can move relative to the encoder cover  52 , the mating connector M 2  is caused to mate through the hole  521   h  without being blocked by the encoder cover  52 . Further, movement of the encoder connector C in the mating direction Y is restricted. That is, when the mating connector M 2  mates with the encoder connector C, escape of the encoder connector C in the mating direction Y is restricted. Therefore, when the mating connector M 2  is caused to mate with the connector C, mating can be securely performed without occurrence of a semi-mated state. 
     In the above-described embodiment, the encoder connector C which has been arranged in the encoder of the servo motor is shown as the example of the connector in the present invention. However, the connector of the present invention is not limited to this example, but may, for example, be arranged in another type of electronic device. 
     Further, in the above-described embodiment, the connector C is of the surface-mounted type mounted on the surface of the circuit board B. However, the connector of the present invention is not limited to this example, but it may be one of such a type that contacts and a retainer are inserted into through-holes to be fixed, for example. 
     Further, in the above-described embodiment, the press-fitting retainer portion  32  is shown as the example of the housing fixing portion of the retainer in the present invention. However, the present invention is not limited to this example, but fixing of the retainer may be performed by adhesion, for example. 
     Further, in the above-described embodiment, eight contacts  1 A to  1 H are shown as the example of the contacts in the present invention. However, the present invention is not limited to this example, but the number of contacts may be seven or less or nine or more, for example. 
     Further, in the above-described embodiment, two retainers  3 A,  3 B are shown as the example of the retainers in the present invention. However, the present invention is not limited to this example, but the number of retainers may be three or more, for example. 
     Further, in the above-described embodiment, the mating recess  21  is shown as the example of the mating portion in the present invention. However, the present invention is not limited to this example, but the mating portion may be a mating projection portion, for example. 
     Advantageously, in the connector C of the present invention, since both the contact  1  and the retainer  3  have resilient portions, the relative movement between the housing  2  and the circuit board B is allowed. However, since the retainer  3  is sandwiched by the restricting portions  22 - 25 , relative movement between the housing  2  and the circuit board B in the mating direction is restricted. Therefore, the connector C of the present invention has a high tolerance to a positional deviation of the mating connector MC in a direction perpendicular to the mating direction, and can securely mate with the mating connector MC without resulting in a semi-mated state.