Patent Publication Number: US-2006019537-A1

Title: Connector

Description:
BACKGROUND OF THE INVENTION  
      This invention relates to a connector, and more particularly to a terminal mounting structure of a connector.  
      Generally, a shielded wire (or cable), having a conductor (also called “core wire”) covered with a shielding wire, is used as a wire such as a signal wire which need to block external noises so as to reduce adverse effects of the external noises to a minimum. In a structure of mounting a connector on such a shielded wire, it is also necessary to shield a connector portion where the shielding wire is peeled and removed from the shielded wire. Therefore, in recent years, there has been used the type of connector in which a connector housing is made of an electrically-conductive material such as aluminum, and the connector portion is shielded by the connector housing.  FIG. 6  shows a connector  1  in which a terminal  5  in the form of a male pin terminal is mounted in a female connector housing  3 . As shown in  FIG. 6 , in order to insulate the terminal  5  from the connector housing  3 , the terminal  5  is disposed in an inner housing  7  made of an insulative material such as a synthetic resin, and the terminal  5  is disposed in the connector housing  3  through the inner housing  7 .  
      More specifically, the terminal  5  includes a body portion  5   b , and an electrical contact portion  5   a  which extends continuously from the body portion  5   b , and is smaller in diameter than the body portion  5   b , the electrical contact portion  5   a  being adapted to be fitted into a mating terminal in the form of a female pin terminal (not shown) . Opposite sides of a portion of the body portion  5   b  are cut to form flat surface portions  5   c . The inner housing  7  is formed into a generally hollow cylindrical shape, and has a stepped through hole  7   a  for the passage of the terminal  5  therethrough. The terminal  5  is passed through the stepped through hole  7   a . A portion of the inner housing  7 , corresponding to the flat surface portions  5   c , is notched into a generally semi-circular shape to form a retaining groove  7   b . Also, a portion of the connector housing  3 , facing to the retaining groove  7   b , is notched into a generally semi-circular shape to form a semi-circular grove  3   a . The terminal  5  is inserted into the stepped through hole  7   a  in the inner housing  7 , and a step portion  5   d  of the terminal  5 , formed at the boundary between the electrical contact portion  5   a  and the body portion  5   b , is brought into abutting engagement with a step portion of the through hole  7   a , thereby positioning the terminal  5  relative to the inner housing  7  in an axial direction. Thereafter, the inner housing  7 , holding the terminal  5 , is inserted into a housing chamber  9  of the connector housing  3 . In this condition, the flat surface portions  5   c  of the terminal  5  is in communication with the exterior of the connector housing  3  via the retaining groove  7   b  and the semi-circular groove  3   a.    
      Then, a stopper  11 , having an engagement portion  11   a  of a substantially U-shape, is inserted into the inner housing  7  through the semi-circular groove  3   a  and the retaining groove  7   b , and a bifurcated portion of the engagement portion  11   a  is brought into engagement with the flat surface portions  5   c  of the terminal  5 . As a result, the terminal  5  is mounted in the connector housing  3  in such a manner that this terminal  5  is prevented from withdrawal and rotation.  
      There is also known a female pin terminal (female terminal) in which a retaining member is inserted into a connector housing from the outside thereof, and is retainingly engaged in a retaining groove formed in an outer peripheral surface of the pin terminal, thereby preventing the withdrawal of the pin terminal (see, for example, Patent Literature 1). Patent Literature 1:JP-A-2003-282175 (Pages 3 to 6,  FIG. 1 )  
      The connector of the above construction is formed by combining the separate parts that is, the retaining member, the terminal, the inner housing and the connector housing together, and therefore the number of the component parts is large, so that the time and labor, required for the assembling operation increase. And besides, manufacturing errors of the various parts are accumulated, which leads to a possibility that the terminal deviates from the proper position relative to the housing chamber of the connector housing (particularly in the radial direction), and there is a fear that the operation for fitting the connector to a mating connector is adversely affected. Therefore, it has been necessary to take measures, for example, to enhance the dimensional precisions of the component parts and to increase the inner diameter of the housing chamber so as to absorb the accumulated errors, thereby preventing the undesirable interference of the connector with the mating connector. Furthermore, in order that the stopper or the retaining member can be engaged with the terminal, the flat surface portions or the retaining groove must be formed at the terminal by processing the relevant portion of the terminal. Therefore, there is possibility for improvement from the viewpoint of the cost reduction.  
     SUMMARY OF THE INVENTION  
      This invention has been made in view of the above circumstances, and an object of the invention is to provide a connector in which an assembling error is small, and an assembling operation is easy.  
      In order to accomplish the above object, a connector of the present invention is characterized by having the following arrangement,  
      (1) A connector comprising:  
      a first housing; and  
      a terminal that comprises: 
          an electrical contact portion adapted to be connected to a mating terminal; and     a body portion continued from the electrical contact portion and formed with a through hole,        

      wherein the first housing is integrally molded with the terminal such that a part of the first housing fills the through hole.  
      (2) A connector according to (1), wherein the through hole extends in a direction perpendicular to a direction in which the terminal is fitted to the mating terminal.  
      (3) A connector according to (1) further comprising a second housing that is made of conductive material,  
      wherein the first housing is made of insulative material and is disposed in the second housing.  
      (4) A method of producing a connector comprising:  
      providing a terminal that comprises an electrical contact portion adapted to be connected to a mating terminal, and a body portion continued from the electrical contact portion and formed with a through hole; and  
      integrally molding a first housing with the terminal such that a part of the housing fills the through hole.  
      (5) A method of producing a connector according to (4) further comprising,  
      disposing the first housing in a second housing made of conductive material,  
      wherein the first housing is made of insulative material.  
      According to the invention, the number of the component parts of the connector is reduced. As a result, accumulated manufacturing errors of the parts are reduced, so that the precision of the connector is enhanced. Therefore, the connector can be positively electrically connected to the mating connector. And besides, the time and labor, required for the assembling operation, can be reduced, so that the production cost can also be reduced. Furthermore, the withdrawal and rotation of the terminal can be positively prevented without the need for forming any retaining portion at the terminal or the need for providing a separate part such as a stopper. Therefore, the reliability of the connector can be enhanced.  
      According to the invention, the outer housing (the connector housing) shields the connector, thereby reducing adverse affects of external noises. Therefore, a wire, such as a signal wire liable to be adversely affected by external noises, can be positively connected to the connector with the simple mechanism. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a perspective view of one preferred embodiment of a connector of the invention, showing its overall construction.  
       FIG. 2  is an exploded, perspective view of the connector of  FIG. 1 .  
       FIG. 3  is a vertical cross-sectional view taken along the line III-III of  FIG. 1 .  
       FIG. 4  is a vertical cross-sectional view taken along the line IV-IV of  FIG. 3 .  
       FIG. 5  is a vertical cross-sectional view of a mating connector for connecting to the connector of the invention.  
       FIG. 6  is a vertical cross-sectional view of a related connector.  
       FIG. 7  is a cross-sectional view taken along the line VII-VII of  FIG. 6 . 
    
    
     DETAIL DESCRIPTION OF PREFERRED EMBODIMENTS  
      One preferred embodiment of the present invention will now be described in detail with reference to the drawings.  
       FIG. 1  is a perspective view of one preferred embodiment of a connector of the invention, showing its overall construction,  FIG. 2  is an exploded, perspective view of the connector of  FIG. 1 ,  FIG. 3  is a vertical cross-sectional view taken along the line III-III of  FIG. 1 ,  FIG. 4  is a vertical cross-sectional view taken along the line IV-IV of  FIG. 3 , and  FIG. 5  is a vertical cross-sectional view of a mating connector for connecting to the connector of the invention. Although the invention can be applied to both of male and female connectors, the illustrated embodiment of FIGS.  1  to  4  is directed to the type of connector in which male pin terminals are used as terminals, and these male pin terminals are mounted in a female connector housing.  
      As shown in FIGS.  1  to  5 , the connector  100  of this embodiment comprises the connector housing  25  which can be fitted to and removed from the mating connector  150 , and the terminals  21  each including an electrical contact portion  21   a  for electrical connection to a corresponding terminal  157  of the mating connector  150 , and a body portion  21   b  extending continuously from the electrical contact portion  21   a . A through hole  28  is formed through the body portion  21   b  of each terminal  21 , and extends in a direction perpendicular to a direction of fitting and removing of the connector housing  25  relative to the mating connector  150 . At least a part of the connector housing  25  is molded integrally with the terminals  21  such that the portions of the connector housing  25  fill respectively the through holes  28  formed respectively through the terminals  21 . More specifically, the connector housing  25  includes an outer housing (In FIGS.  1  to  4 , reference numeral  25  is used to designate both of the connector housing  25  and the outer housing), and an inner housing  23  which is separate from the outer housing, and can be mounted in the outer housing. The inner housing  23  is molded integrally with the terminals  21  such that portions of the inner housing  23  fill respectively the through holes  28 . When the inner housing  23  is mounted in the outer housing, the terminals  21  are mounted in the connector housing  25 . The outer housing is made of an electrically-conductive material.  
      Details of the connector  100  of this construction will be described below.  
      As shown in FIGS.  1  to  4 , the connector  100  of this embodiment comprises the terminals (that is, the male pin terminals)  21 , and the connector housing (female connector housing)  25  including the inner housing  23  and the outer housing. In the embodiment shown in FIGS.  1  to  4 , the three terminals  21 , arranged on a straight line, are disposed in the connector housing  25  through the inner housing  23 .  
      Each terminal (male pin terminal)  21  is made of an electrically-conductive material such for example as nickel-plated copper, and is formed into a cylindrical shape having the electrical contact portion  21   a  and the body portion  21   b  which are continuous with each other. The electrical contact portion  21   a  is smaller in diameter than the body portion  21   b  so as to be fitted into a resilient contact piece  151  of a substantially hollow cylindrical shape, which is an electrical contact portion of the mating connector  150  (described later) . A distal end of the electrical contact portion  21   a  is round chamfered so that the electrical contact portion  21   a  can be easily fitted into the resilient contact piece  151 . The through hole  28 , defined by a circular inner peripheral surface  21   c , is formed in the body portion  21   b , and extends through the body portion  21   b  in a diametrical direction of the body portion  21   b . An internally-threaded portion  21   d  is formed in a proximal end of the body portion  21   b , and extend in an axial direction. A bolt (not shown) is passed through a hole in a ring terminal or the like fixedly secured to one end portion of a conductor of a wire (not shown), and is threaded into the internally-threaded portion  21   d , thereby fixing the wire to the terminal  21 .  
      The inner housing  23  is made of an insulative synthetic resin such for example as PPS (polyphenylene-sulfide), and this inner housing  23  is molded integrally with the three terminals  21 , arranged on a straight line, in such a manner that portions of the inner housing  23  fill respectively in the through holes  28  formed respectively through the terminals  21 . The inner housing  23  includes three body portions  23   a  of a round cup-shape with a closed bottom, and a generally-oval flat plate  23   b  interconnecting upper ends of the three body portions  23   a . A bottom portion  23   c  of each body portion  23   a  has a cylindrical portion  23   d  extending therefrom in a direction away from the open end of the body portion  23   a . The cylindrical portion  23   d  is molded integrally on the body portion  21   b  of the corresponding terminal  21  so that the through hole  28  can be filled with the molded resin. As a result, part of the synthetic resin, forming each bottom portion  23   c  and the corresponding cylindrical portion  23   d , flows into the through hole  28  in the corresponding terminal  21 , so that the terminals  21  are integrally connected to the inner housing  23 , and therefore are positively fixed thereto.  
      That portion of the connector housing  25  except the inner housing  23 , that, the outer housing, is made of the electrically-conductive material such for example as aluminum, and has a substantially rectangular box-shape. A fitting hole (space)  27  of a generally oval cross-section is formed in one end surface (upper end surface in  FIG. 3 )  25   a  of the connector housing (outer housing)  25 , and is defined by straight opposed side surfaces  25   b  extending respectively along longer sides of the connector housing  25  and generally semi-circular opposite end surfaces  25   c  extending respectively along shorter sides of the connector housing  25 . Similarly, an oval hole (space)  29  of a generally oval cross-section is formed in the other end surface  25   d  of the connector housing  25 , and is defined by straight opposed side surfaces  25   e  extending respectively along the longer sides of the connector housing  25  and generally semi-circular opposite end surfaces  25   f  extending respectively along the shorter sides of the connector housing  25 . Three through holes  31  of a circular shape are formed through a partition wall  25   g  forming the boundary between the fitting hole  27  and the oval hole  29 , and the fitting hole  27  and the oval hole  29  communicate with each via these through holes  31 . The through holes  31  are arranged at a pitch equal to the pitch of the terminals  21 .  
      The fitting hole  27  has two holes  27   a  and  27   b  which are similar in shape to each other, and have a substantially oval shape. The first fitting hole  27   a  of a slightly larger size is disposed close to the one end surface  25 , and the second fitting hole  27   b  is disposed close to the partition wall  25   g , and is smaller than the first fitting hole  27   a . Thus, the fitting hole  27  is formed as a stepped hole. The first fitting hole  27   a  is slightly smaller in size than a packing  153  mounted on the mating connector  150  (see  FIG. 5 ). The size of the second fitting hole  27   b  is equal to an outer size of the inner housing  23 , and the inner housing  23  is fitted into the second fitting hole  27   b . Internally-threaded portions  25   h , corresponding respectively to externally-threaded portions (not shown) formed oh the mating connector housing  150 , as well as positioning pin holes  26 , corresponding respectively to positioning pins  155  formed on the mating connector  150 , are formed in the one end surface  25   a  of the connector housing  25 .  
      A terminal holder  33  has a substantially oval shape, and is made of a synthetic resin such as PPS. Three circular walls  33   b  are formed on and extend upwardly from a substantially oval base  33   a  of the terminal holder  33 . A circular hole  35  is formed through a central portion of that portion of the base  33   a  encircled by each circular wall  33   b , the circular hole  35  being slightly larger in diameter than the body portion  21   b  of the terminal  21 . A packing  37  is mounted within each circular wall  33   b , and a packing  39  is mounted at an outer peripheral portion of the base  33   a , the packings  37  and  39  being made of a rubber material such for example as acrylic rubber.  
      Next, a procedure of assembling the connector  100  will be described. As shown in  FIGS. 3 and 4 , the inner housing  23 , having the terminals  21  integrally molded therein, is fitted into the second fitting hole  27   b  of the outer housing of the connector housing  25  while passing the body portions  21   b  of the terminals  21  respectively through the through holes  31  in the outer housing of the connector housing  25 . Then, the packings  33  are inserted respectively into the circular walls  33   b of the terminal holder  33 , and the packing  39  is mounted on the outer periphery of the terminal holder  33 . Thereafter, the terminal holder  33 , together with the packing  39 , is inserted into the oval hole  29  in the connector housing  25  while passing the body portions  21   b  of the terminals  21  through the respective packings  37  and also through the respective holes  35  in the terminal holder  33 .  
      As a result, a seal is formed between the body portion  21   b  of each terminal  21  and the corresponding circular wall  33   b of the terminal holder  33 , and also a seal is formed between the base  33   a  of the terminal holder  33  and the oval hole  29  in the connector housing  25 . One end portions of the body portions  21   b  of the terminals  21  project outwardly from the terminal holder  33  through the respective holes  35 . Then, the inner housing  23  and the terminal holder  33  are pressed toward each other so as to eliminate a gap therebetween, and push nuts  41  are fitted on the body portions  21   b , respectively, and the terminal holder  33  is held by outer peripheral portions of the push nuts  41 . Thus, the connector  100  is assembled.  
      As shown in  FIG. 5 , the mating connector  150  comprises a male connector housing  159 , and the three female pin terminals (terminals)  157  which are mounted in the connector housing  159 , and are arranged on a straight line in corresponding relation to the connector  100 . The resilient contact piece  151  is provided within one end portion of the terminal  157  of a hollow cylindrical shape made of an electrically-conductive material, and a conductor  165  of a shielded wire  163  is press-fastened to the other end portion of this terminal. The externally-threaded portions (not shown), corresponding respectively to the internally-threaded portions  25   h  formed in the connector housing  25  of the connector  100 , are formed in the male connector housing  159 , and the positioning pins  155 , corresponding respectively to the positioning pin holes  26  formed in the connector housing  25 , are formed on the male connector housing  159 .  
      The electrical contact portions  21   a  of the terminals  21  are fitted respectively into the resilient contact pieces  151  while inserting the positioning pins  155  respectively into the positioning pin holes  26 , and the connector housing  25  is brought into abutting engagement with the male connector housing  159 , and the externally-threaded portions (not shown) are threaded respectively into the internally-threaded portions  25   h , thereby fastening the two connector housings together. As a result, the terminals  21  are electrically connected respectively to the terminals (female pin terminals)  157 .  
      In the terminal mounting structure of the connector  100  of this embodiment, the inner housing  23 , molded integrally with the terminals  21 , is disposed in the outer housing of the connector housing  25 , and by doing so, the terminals  21  are disposed in the connector housing  25  through the inner housing  23 . Therefore, the number of the component parts of the connector  100  is reduced. As a result, accumulated manufacturing errors of the parts are reduced, so that the connector can be positively electrically connected to the mating connector  150 . And besides, the time and labor, required for the assembling operation, can be reduced, so that the production cost can also be reduced. Furthermore, the through hole  28  is formed through the body portion  21   b  of each terminal  21 , and extends in the direction perpendicular to the direction of fitting and removing of the connector  100 , and the inner housing  23  is molded integrally with the terminals  21  such that portions of the inner housing  23  fill respectively in the through holes  28 . Therefore, the withdrawal and rotation of the terminals  21  can be positively prevented without the need for forming any retaining portion at each terminal or the need for providing separate parts such as stoppers. Therefore, the reliability of the connector  100  can be enhanced.  
      In the terminal mounting structure of the connector  100  of this embodiment, the outer housing of the connector housing  25  is made of the electrically-conductive material. Therefore, the connector housing  25  shields the connector  100 , thereby reducing adverse affects of external noises. Therefore, the wires  163 , such as signal wires liable to be adversely affected by external noises, can be positively connected to the connector with the simple mechanism.  
      The present invention is not limited to the above embodiment, and suitable modifications, improvements and so on can be made. The material, shape, dimensions, numerical values, form, number, disposition, etc., of each of the constituent elements of the above embodiment are arbitrary, and are not limited in so far as the invention can be achieved.  
      For example, in the above embodiment, although the connector housing comprises the outer housing and the inner housing which are separate from each other, there can be used a connector housing having an outer housing and an inner housing which are molded integrally with each other, using a synthetic resin. In this case, also, part of the connector housing (that is, the single connector housing) is molded integrally with the terminals, and this is desirable since the number of the component parts is reduced. With respect to a shielding function of the connector housing of the type in which the outer and inner housings are molded integrally with each other, using the synthetic resin, a suitable shielding member is used for this purpose.