Patent Publication Number: US-8528204-B2

Title: Method for producing connector terminal and method for assembling multi-stage connector

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application is a continuation of PCT application No. PCT/JP2011/052297, which was filed on Feb. 2, 2011 based on Japanese Patent Application (No. 2010-022438) filed on Feb. 3, 2010, the contents of which are incorporated herein by reference. Also, all the references cited herein are incorporated as a whole. 
    
    
     BACKGROUND 
     1. Technical Field 
     The present invention relates to a method for producing a connector terminal for a multi-stage connector and a method for assembling a multi-stage connector in which terminals obtained by the method for producing the connector terminal are assembled to a connector housing. 
     2. Background Art 
     A multi-stage connector having a plurality of, upper and lower, stages in terminal arrangements as shown in  FIG. 11  is, for example, known as a connector which is directly mounted on a printed circuit board (see e.g., JP-A-11-162611). In such a multi-stage connector, terminal elements  521  and  522  are inserted into and fixed to press-fit holes  503  formed on a rear wall  502  of a connector housing  501 . Lengths of rear leg sections extending from a rear part of the connector housing  501  are different from each other between the terminal elements  521  at the upper stage and the terminals  522  at the lower stage, as shown in  FIG. 13A  so that total lengths are different from each other. 
     As a producing method of collectively molding the terminal elements  521  and  522  having different lengths by a press punching process with a good process yield, a method is proposed in which two kinds of terminal elements  521  and  522  are alternately arranged in opposite orientations as shown in  FIG. 13B  so as to be molded, and after the molding, the cutting points d connecting to respective carriers  511  and  522  are cut off, thereby obtaining separated terminal elements  521  and  522 . 
     However, in a case where the number of kinds of lengths of terminal elements is increased, the yield of the material is degraded so that the cost is increased. 
     Therefore, a method of press processing six kinds of terminal elements  621  to  626  (terminal elements for respective stages) having different lengths by using different dies is sometimes taken as shown in  FIG. 12 . 
     SUMMARY 
     However, in the above case, the cost of dies or the processing cost is unnecessarily increased so that the producing cost is increased. In addition, in a case where there is only a material of a band plate having a predetermined width, the yield cost of the material is deteriorated, similarly. 
     The invention is made in view of the above circumstances, and the purpose of the invention is to provide a method for producing a connector terminal in which all of the terminals having the lengths of stages which are different from each other are collectively formed by a single die while minimizing material loss as much as possible, and to provide a method for assembling a multi-stage connector by using the connector terminals obtained by the above method. 
     In order to solve the above problems, there is provided a method for producing a connector terminal according to a first aspect of the invention by forming a plurality of terminal elements from a single band-shaped metal plate by press punching wherein the terminal elements are to be attached to a single connector housing and are 2N (where, N=1, 2, 3, . . . ) rod-shaped terminal elements having overall lengths varied in sequence because lengths of rear leg sections extending from a rear part of the connector housing are different from each other, are formed by press punching out of a single band-shaped metal plate. In the producing method, a plurality of rod bodies bridged between a first carrier and a second carrier which are disposed along both side edges of the metal plate are arranged on the metal plate in such a manner that a lengthwise direction of the rod bodies is perpendicular to a longitudinal direction of the metal plate. A pair of combined terminal elements in series on one rod body is arranged in such matter that the 2N terminal elements are classified such that the first N terminal elements in descending order of length are in a first group, and the remaining N terminal elements are in a second group. The n-th terminal element (where, n=1, 2, 3, . . . ; and n≦N) from the shortest one and the n-th terminal element from the longest one are selected from among the terminal elements of the first and second groups and are combined one by one. Under the above condition, each of the terminal elements is formed from the metal plate by press punching. 
     A method for producing a connector terminal according to a second aspect of the invention, is based on the first aspect of the invention. In a case that the n-th terminal element from the shortest one and the n-th terminal element from the longest one are selected from among the terminal elements of the first and second groups and are combined one by one and then the combined two terminal elements are arranged in series on the single rod body, the combined two terminal elements are arranged on the rod body at the n-th row arranged on the metal plate, and a set of the terminal elements formed by the rod bodies in the first to the N-th rows are made to be one unit, and two or more units of terminals are formed from the one metal plate. 
     A method for producing a connector terminal according to a third aspect of the invention, is based on the second aspect of the invention. The producing method includes a process of obtaining a plate shaped molded article including the carriers and the rod bodies, a cutting-off process of cutting off the molded article at a connection position between the two terminal elements on each rod body under a condition that the carriers are connected thereto so as to cut off a first terminal row having the terminal elements in the first group and a second terminal row having the terminal elements in the second group, and a bending process in which a bending force in a direction perpendicular to the plate face is applied to the plate shaped molded article cut off in the cutting-off process so as to form a L-shaped bent section which is adapted to form a rear leg section on each of the terminal elements constituting the first terminal row and the second terminal row, thereby forming, on each terminal element, a horizontal straight section having an electric contact section to be electrically contacted with a counter terminal at a front end side and a vertical straight section formed by being bent vertically downward from a rear end of the horizontal straight section. In the bending process, by performing the bending process while adjusting a position of the bent section of each terminal element in the vertical direction, heights of the rear leg sections of the terminal elements having different lengths from the lower end parts of the vertical straight sections to the bent sections are differentiated in the order of the lengths of the terminal elements under a condition that the front end positions of the electric contact sections of all of the terminal elements in the respective first and second terminal rows are aligned. 
     A method for assembling a multi-stage connector having a terminal arrangement of 2N (where N=1, 2, 3, . . . ) stages in the vertical direction according to a fourth aspect of the invention, is based on the producing method according to the third aspect of the invention. The method for assembling a multi-stage connector includes: a process of obtaining the first terminal row and the second terminal row having the carriers; a second terminal row assembling process in which horizontal straight sections of the terminal elements of the second terminal row are inserted into respective press-fit holes arranged from the lower end to the N-th stages at a rear wall of a connector housing of the multi-stage connector, and thereby an electric contact section of each terminal element of the second terminal row is accommodated in a hood of the connector housing; a second carrier cutting-off process of performing, after the above process, cutting-off of the second carrier to which the rear leg sections of the terminal elements are connected; a first terminal row assembling process in which after performing the second carrier cutting-off process, horizontal straight sections of the terminal elements of the first terminal row are inserted into respective press-fit holes arranged from the top to the N-th stages at the rear wall of the connector housing of the multi-stage connector, and thereby an electric contact section of each terminal element of the first terminal row is accommodated in the hood of the connector housing; and a first carrier cutting-off process of performing, after the above process, cutting-off of the first carrier to which the rear leg sections of the terminal elements are connected. 
     In accordance with the first aspect of the invention, since two kinds of, i.e., long and short terminal elements are combined and arranged on each single rod body, the lengths of the rod bodies arranged on the metal plate can be equalized so that the connector terminals can be collectively and efficiently produced by press punching while minimizing material loss. Therefore, it is possible to minimize the cost of a die or processing as much as possible, and thereby to reduce the producing cost of the terminals. 
     In accordance with the second aspect of the invention, since many kinds of terminal elements are collectively formed while aligning the arrangement order of the terminal elements as the order in lengths of the terminal elements, the terminal elements can be readily assembled to the connector housing under a condition that the terminal rows are connected to the carrier. 
     In accordance with the third aspect of the invention, since the first terminal row in which the long terminal elements are collected and the second terminal row in which the short terminal elements are collected, are respectively subjected to the bending process, it is possible to reduce the number of times of bending processes and kinds of dies for processing, thereby reducing the processing cost. 
     In accordance with the fourth aspect of the invention, the terminal elements in the multi-stages at the lower side and the terminal elements in the multi-stages at the upper side can be collectively inserted into and assembled to the press-fit holes of the connector housing with respect to the lower and upper side stages while the terminal elements are connected to the carriers. Therefore, the number of times of the press fitting can be reduced, thereby reducing troubles in the assembling. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view showing a partial structure of a molded article obtained by a press processing according to an embodiment of the invention. 
         FIG. 2  is an enlarged perspective view showing a main part of the molded article shown in  FIG. 1 . 
         FIG. 3  is a plan view showing the molded article. 
         FIG. 4  is a plan view showing a state that the molded article is cut and separated into a first terminal row and a second terminal row. 
         FIGS. 5A and 5B  are schematic views showing a state that rear leg sections of terminal elements of the first terminal row and rear leg sections of terminal elements of the second terminal row are subjected to a bending process,  FIG. 5A  is a perspective view showing a state that the terminal elements of the second terminal row shown in  FIG. 4  are subjected to the bending process, and  FIG. 5B  is a perspective view showing a state that the terminal elements of the first terminal row shown in  FIG. 4  are subjected to the bending process. 
         FIGS. 6A and 6B  are elevational side views showing the terminal elements of the first terminal row and the terminal elements of the second terminal row, and  FIG. 6A  and  FIG. 6B  are elevational side views respectively showing the terminal rows shown in  FIG. 5A  and  FIG. 5B . 
         FIG. 7  is a perspective view showing a state that the terminal elements of the second terminal row shown in  FIG. 5A  are going to be press-fitted into a connector housing. 
         FIG. 8  is a perspective view showing a state that after the terminal elements of the second terminal row are press-fitted thereinto, a second carrier is cut off, and then the terminal elements of the first terminal row shown in  FIG. 5B  are going to be press-fitted into the connector housing. 
         FIG. 9  is a perspective view showing a state that the pres-fitting of the terminal elements of the first terminal row into the connector housing is completed. 
         FIG. 10  is a perspective view showing a state that a first carrier is cut off after the press-fitting. 
         FIG. 11  is a cross sectional view showing an example of a related art multi-stage connector. 
         FIG. 12  is a perspective view showing structures of the terminal elements to be used in a six-stage type multi-stage connector. 
         FIGS. 13A and 13B  are schematic views showing structures of terminal elements to be used in the related art multi-stage connector shown in  FIG. 11 ,  FIG. 13A  is a plan view showing the structures of the terminal elements to be used in the related art multi-stage connector shown in  FIG. 11 , and  FIG. 13B  is a plan view showing a molded article having terminal elements which are collectively formed by press molding. 
     
    
    
     DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS 
     An embodiment of the invention is described below with reference to accompanying drawings. 
       FIG. 1  is a perspective view showing a partial structure of a molded article obtained by a press processing by a method according to the embodiment.  FIG. 2  is an enlarged perspective view showing a main part of the molded article.  FIG. 3  is a plan view showing the molded article. 
     A producing method of the embodiment is configured such that six rod-shaped terminal elements  21  to  26  which are to be attached to a single connector housing  100  and respectively have rear leg sections  33  extending from a rear side of the connector housing  100  and having different lengths, and thereby have total lengths varied in sequence, are formed from a single band-shaped metal plate W by press punching. In the producing method of the embodiment, a first carrier  11  and a second carrier  12  are first arranged on the metal plate W along both side edges of the metal plate W. In addition, a plurality of rod bodies A 1  to A 3  bridged between the first carrier  11  and the second carrier  12  are arranged on the metal plate W in such a manner that the lengthwise direction of the rod bodies A 1  to A 3  is perpendicular to the longitudinal direction X of the metal plate W. 
     On the other hand, the six terminal elements  21  to  26  having different total lengths to be used for a multi-stage connector having six stages are classified such that three terminal elements in descending order of length from the longest one are in a first group and the remaining three terminal elements are in a second group. The n-th terminal element  24 ,  25  or  26  from the shortest one and the n-th terminal element  21 ,  22  or  23  from the longest one are selected from among the terminal elements  21  to  26  in the respective groups (where n=1, 2, 3, . . . ; and n≦N) and are combined one by one. The combined two terminal elements  21  and  26 ,  22  and  25 , and  23  and  24  are arranged in series on the rod bodies A 1  to A 3  respectively. 
     Each of the terminal elements  21  to  26  has, as a common structure, an electric contact section  31  which is disposed at a front end and is to be contacted with a counter terminal, a press-fit engagement section  32  which is disposed at the rear side thereof and is to be engaged with a press-fit hole of the connector housing  100 , and a rear leg section  33  which protrudes to the outside from a rear side of the connector housing  100  when it is set in the connector housing  100 . Each of the terminal elements  21  to  26  has a substrate connection section  34  disposed at a base end (also referred to as a rear end) of the rear leg section  33 . The set of the terminal element  21 ,  22  or  23  in the first group and the terminal element  24 ,  25  or  26  in the second group are arranged on each of the rod bodies A 1  to A 3  so as to be in orientations opposite to each other. The front ends of the electric contact sections  31  are coupled with each other at each of connection positions a to c to be cut off, and the rear ends of the substrate connection sections  34  are respectively coupled to the first carrier  11  and the second carrier  12  with connection positions d to be cut off therebetween. 
     In the above case, each two of the terminal elements  21  to  26  are arranged on the rod body at the n-th row in the rod bodies A 1  to A 3  arranged on the metal plate W. While a set of terminal elements  21  to  26  formed by the rod bodies A 1  to A 3  from the first row to the third row are made as one unit, two or more units of terminal elements  21  to  26  are formed from the single metal plate W. 
     To be specific, the first longest terminal element  21  and the first shortest terminal element  26  are combined and are arranged in series on the one rod body A 1  disposed at the first row. In addition, the second longest terminal element  22  and the second shortest terminal element  25  are combined and are arranged in series on the one rod body A 2  disposed at the second row. Further, the third longest terminal element  23  and the third shortest terminal element  24  are combined and are arranged in series on the one rod body A 3  disposed at the second row. By making the set of the terminal elements  21  to  26  formed by the rod bodies A 1  to A 3  from the first row to the third row as one unit A, two or more units of terminal elements  21  to  26  are formed from the single metal plate W. 
     In accordance with the producing method, since the two kinds of, i.e., long and short terminal elements  21  and  26 ,  22  and  25 , or  23  and  24  are combined and arranged on each one of the rod bodies, the lengths of the rod bodies A 1  to A 3  arranged on the metal plate W can be equalized. Consequently, it is possible to collectively and efficiently produce the connector terminals  21  to  26  while minimizing the material loss as much as possible. Therefore, it is possible to suppress the cost of the die or processing to its minimum, and thereby to reduce the production cost of the terminal elements. In addition, since various kinds of terminal elements  21  to  26  are collectively molded while aligning the arrangement order of the terminal elements  21  to  26  as the order in lengths of the terminal elements  21  to  26 , the terminal elements  21  to  26  can be readily assembled to the connector housing  100  of the multi-stage connector under a condition that terminal rows F 1  and F 2  are connected to the carriers  11  and  12 . 
     Next, a sequence of forming the multi-stage connector from the molded article  10  molded as shown in  FIG. 3  by assembling the terminal elements  21  to  26  to the connector housing  100 , is described below. 
     First, the plate shaped molded article  10  including the carriers  11  and  12  and the rod bodies A 1  to A 3  as shown in  FIG. 3 . is formed. Next, the molded article  10  is cut at the connection positions a to c (see  FIG. 3 ) of each two of the terminal elements  21  to  26  arranged on the respective rod bodies A 1  to A 3  as shown in  FIG. 4  under a condition that the carriers  11  and  12  are connected to the molded article  10 , and thereby the molded article  10  is cut and separated into the first terminal row F 1  constituted by the set of terminal elements  21  to  23  in the first group and the second terminal row F 2  constituted by the set of terminal elements  24  to  26  in the second group. 
     Next, a bending force in a direction perpendicular to the plate face is applied to the cut off plate shaped molded article (the first terminal row F 1  and the second terminal row F 2 ), and thereby L-shaped first bent sections e 1  constituting the rear leg sections  33  are formed on the respective terminal elements  21  to  26  constituting the first terminal row F 1  and the second terminal row F 2  as shown in  FIGS. 5A and 5B  and  FIGS. 6A and 6B . With this, a horizontal straight section  35  having an electric contact section  31  to be electrically contacted with a counter terminal disposed at a front end side and a vertical straight section  36  which is bent vertically downward from a rear end of the horizontal straight section  35  can be formed on each of the terminal elements  21  to  26 . By adding a second bent section e 2  at the same time of the bending process, a substrate connection section  34  in parallel to the horizontal straight section  35  is formed. 
     Meanwhile, in the bending process, by performing the bending process while adjusting a position of the first bent section e 1  of each of the terminal elements  21  to  26  in the vertical direction, heights of the rear leg sections  33  of the terminal elements  21  to  26 , having different lengths, from the lower end parts (second portions e 2 ) of the vertical straight sections  36  to the first bent sections e 1  are differentiated in the order of the lengths of the terminal elements  21  to  26  under a condition that the front end positions of the electric contact sections  31  of all the terminal elements  21  to  26  in the respective first and second terminal rows F 1  and F 2  are aligned. 
     Thus, since the first terminal row F 1  having the set of long terminal elements  21  to  23  and the second terminal row F 2  having the set of short terminal elements  24  to  26  are respectively subjected to the bending process so as to cause the terminal elements  21  to  26  to be collectively bent with respect to the first and second terminal rows F 1  and F 2 , it is possible to reduce the number of times of bending processes and kinds of dies for processing, and thereby to reduce the processing cost. 
     Next, as shown in  FIG. 7 , the horizontal straight sections  35  of the terminal elements  24  to  26  of the second terminal row F 2  with the carrier  12  produced as in the above are press-fitted into press-fit holes  124  to  126  arranged from the lower end to the third stages at a rear wall  120  of the connector housing  100  of the multi-stage connector having six stages, and thereby the electric contact sections  31  of the terminal elements  24  to  26  of the second terminal row F 2  are accommodated in a hood of the connector housing  100  (a second terminal row assembling process). After that, the second carrier  12  connected to the rear leg sections  33  of the terminal elements  24  to  26  is cut off at the connection positions d to be separated therefrom (a second carrier cutting-off process). 
     Next, as shown in  FIGS. 8 and 9 , the horizontal straight sections  35  of the terminal elements  21  to  23  of the first terminal row F 1  are press-fitted into press-fit holes  121  to  123  arranged from the top to the third stages at the rear wall  120  of the connector housing  100 , and thereby the electric contact sections  31  of the terminal elements  21  to  23  are accommodated in the hood of the connector housing  100  (a first terminal assembling process). After that, the first carrier  11  connected to the rear leg sections  33  of the terminal elements  21  to  23  is cut off at the connection positions d to be separated therefrom (a first carrier cutting-off process), thereby the multi-stage connector having six stages can be completed as shown in  FIG. 10 . 
     Thus, the terminal elements  24  to  26  in three stages at the lower side and the terminal elements  21  to  23  in three stages at the upper side can be collectively inserted into the press-fit holes  121  to  126  of the connector housing  100  so as to be assembled to the connector housing  100  while the carriers  11  and  12  are connected to the terminal elements  21  to  26 . Therefore, the number of times of press-fitting can be reduced and trouble in the assembling can be suppressed. 
     While a case in which the six kinds of terminal elements  21  to  26  having different lengths to be used in the multi-stage connector having six stages are produced and assembled to the connector housing  100 , is described in the above embodiment, the number of stages is not limited thereto. 
     For example, in a case where a multi-stage connector having terminal arrangement of arbitrary 2N (where, N=1, 2, 3, . . . ) in the vertical direction is formed, 2N terminal elements to be used therein is classified such that N terminals from the longest one are in a first group and the remaining N terminals are in a second group. The n-th terminal element (where, n=1, 2, 3, . . . , and n&lt;=N) from the shortest one and the n-th terminal element from the longest one are selected from the terminal elements in the respective groups and are combined one by one. The combined two terminal elements are arranged in series on each of the rod bodies. At that time, the two terminal elements are arranged on the rod body at the n-th row arranged on the metal plate, and by making the set of the terminal elements formed by the rod bodies from the first to the third rows as one unit, two or more units of terminal elements are molded from the single metal plate. 
     In addition, the terminal elements formed as in the above are collectively subjected to the bending process, and thereby assembled to the connector housing of the multi-stage connector having 2N stages (where, N=1, 2, 3, . . . ). At that time, first, the horizontal straight sections of the terminal elements (shorter ones) of the second terminal row are inserted into the press-fit holes arranged from the lower end to the N-th stages of the connector housing, and then the second carrier is cut off. Next, the horizontal straight sections of the terminal elements (longer ones) of the first terminal row are inserted into the press-fit holes arranged from the top to the N-th stages of the connector housing, and then the first carrier is cut off. By the above processes, the multi-stage connector having arbitrary 2N stages can be achieved. 
     While the invention is described in detail by referring to a specific embodiment, it is understood by those of ordinary skill in the art that various modifications and changes can be made without departing from the sprit and scope of the invention.