Abstract:
In a connector continuity checking device comprising continuity checking pins  38  corresponding to terminals  41  in a connector  32,  and lance displacement detecting pins  34  corresponding to lances  44  having elasticity and adapted to lock the terminals, the continuity checking pins  38  are respectively provided at their distal ends with concave terminal receiving portions  55  to receive distal ends of the terminals  41 , and the lance displacement detecting pins  34  are respectively provided at their distal ends with concave lance receiving portions  56  to receive distal ends of the lances  44.  The concave terminal receiving portions  55  and the concave lance receiving portions  56  are formed in a U-shape or a V-shape in cross section.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to a connector continuity checking device, which can perform inspection of electrical continuity and detection of incomplete insertion of terminals in a connector.  
           [0003]    1. Description of the Related Art  
           [0004]    In FIG. 7, a conventional connector continuity checking device  1  has a connector holding part  3  substantially in a shape of gateposts in which a connector  2  is adapted to be set, and a checking part  4  arranged movably back and forth with respect to the connector holding part  3 .  
           [0005]    The checking part  4  has a main block  5  of a hollow rectangular shape. In a connector engaging chamber  6  in the main block  5  are arranged a plurality of continuity checking pins  8  in a columnar shape which is capable of contacting with terminal  7  (see FIG. 8) in the connector  2 , and a plurality of lance displacement detecting pins  9  in a form of a plate having a tapered tip end for detecting incomplete insertion of the terminals  7  (see FIG. 8).  
           [0006]    The continuity checking pins  8  and the lance displacement detecting pins  9  are formed of metal. Each of the lance displacement detecting pins  9  includes an integral block portion  10  in a rectangular shape at its base side. The continuity checking pin  8  and the lance displacement detecting pin  9  are separated by an insulating sleeve  11  and fixed by press fitting. In other words, the insulating sleeve  11  of synthetic resin is press fitted around the continuity checking pin  8 , and the block portion  10  made of metal is press fitted around the insulating sleeve  11 .  
           [0007]    The continuity checking pin  8 , the insulating sleeve  11  and the lance displacement detecting pin  9  constitute a piece of set pin  12 . It is to be noted that the insulating sleeve  11  is formed from a round rod by drilling and cutting around an outer periphery, and provided with a flange  13  for positioning and stopping the block portion  10  at its rearward end.  
           [0008]    The continuity checking pin  8  is resiliently biased toward the connector holding part  3  by means of a coil spring  14  (see FIG. 8). The block portion  10  of the lance displacement detecting pin  9  is guided along a bore  15  in the main block  5  to move back and forth. The connector holding part  3  is fixed to a frame  16  by way of coil springs  17 . The main block  5  is designed so as to slide on the frame  16  along guide shafts  19  by way of links (not shown) by actuating a lever  18  to rotate.  
           [0009]    When the connector  2  is inserted into the connector holding part  3  from above in FIG. 7, and the lever  18  is rotated forward to move the main block  5  toward the connector  2 , a front half portion of the connector  2  is inserted into the main block  5  and distal ends of the continuity checking pins  8  are brought into contact with distal ends of the terminals  7 . Electric wires  20  (see FIG. 7) connected to the terminals and electric wires  21  connected to the continuity checking pins  8  are connected to a checker (not shown), and presence of electrical continuity in the terminals  7  can be confirmed by flashing of a lamp of the checker.  
           [0010]    When one of the terminals has not been completely inserted into a terminal receiving chamber  23  in a connector housing  22  as represented by an upper terminal  7   a  in FIG. 8, a flexible locking lance  24  in the connector housing  22  is still in a flexed state in a flexing space  25 . Accordingly, a distal end of the lance displacement detecting pin  9  is abutted against a tip end of the flexible locking lance  24  to prevent a further movement of the continuity checking pin  8 . Thus, the continuity checking pin  8  cannot be brought into contact with the terminal  7   a , resulting in a defective conduction, and the incomplete insertion of the terminal  7   a  can be detected.  
           [0011]    By the way, in the above described prior art, it has been concerned that when the distal end of the lance displacement detecting pin  9  is abutted against the distal end of the flexible locking lance  24 , its speed and load may move both the lance displacement detecting pin  9  and the flexible locking lance  24  in either of upward and downward directions. In this case, the flexible locking lance  24  is likely to escape in upward or downward direction and there is a fear that even the incomplete insertion like the terminal  7   a  may be recognized as being electrically continued. It is to be noted that the above described may be concerned with a position of the flexible locking lance  24  within a dimensional tolerance, a size of the terminal  7  within the dimensional tolerance and so on.  
           [0012]    Meanwhile, because the continuity checking pin  8  and the lance displacement detecting pin  9  are integrally fixed, there is a fear that in case where the lance displacement detecting pin  9  is not positioned accurately, the continuity checking pin  8  becomes out of positional alignment with the terminal  7 , when the lance displacement detecting pin  9  is inserted into the flexing space  25  from a front opening  26  (see FIG. 8). Thus accuracy of the continuity detection may be deteriorated.  
           [0013]    The present invention has been made in view of the above circumstances, and its object is to provide a connector continuity checking device with high accuracy.  
         SUMMARY OF THE INVENTION  
         [0014]    In order to solve the above described problems, there is provided according to the present invention, a connector continuity checking device comprising continuity checking pins corresponding to terminals in a connector, and lance displacement detecting pins corresponding to lances having elasticity and adapted to lock the terminals, wherein the continuity checking pins are respectively provided at their distal ends with concave terminal receiving portions to receive distal ends of the terminals, and the lance displacement detecting pins are respectively provided at their distal ends with concave lance receiving portions to receive distal ends of the lances.  
           [0015]    According to another aspect of the invention, the concave terminal receiving portions and the concave lance receiving portions are formed in a U-shape or a V-shape in cross section.  
           [0016]    According to a first aspect of the present invention, when the distal end of the continuity checking pin has come in contact with the distal end of the terminal for the check, the terminal is guided by the terminal receiving portion. Because the continuity checking pin and the lance displacement detecting pin are integrally fixed, even though the lance displacement detecting pin is not accurately positioned, the continuity checking pin can reliably catch the distal end of the terminal. The check with high accuracy can be thus obtained.  
           [0017]    Moreover, in case where the terminal has been incompletely inserted, when the distal end of the lance displacement detecting pin has come in contact with the distal end of the lance, the distal end of the lance is guided by the lance receiving portion. Even though the lance displacement detecting pin is abutted against the lance on occasion of the check and apt to wobble with its speed and load, the lance displacement detecting pin will not escape from the distal end of the lance, since the distal end of the lance has been inserted into the lance receiving portion. Similarly, even though there are differences in the position of the lance within the dimensional tolerance and in the size of the terminal within the dimensional tolerance, the lance displacement detecting pin will not escape from the distal end of the lance. Accordingly, the incomplete insertion of the terminal can be reliably detected, and the check with high accuracy can be obtained.  
           [0018]    According to the second aspect of the invention, guiding the distal ends of the terminal and the lance will be facilitated, and a wider guiding area can be obtained than with a simple recess.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0019]    [0019]FIG. 1 is a sectional view of an essential part of a connector continuity checking device according to one embodiment of the present invention;  
         [0020]    [0020]FIG. 2 is a sectional view of the essential part in a state where a terminal is incompletely inserted in contrast with FIG. 1 ;  
         [0021]    [0021]FIG. 3 is an exploded perspective view of a continuity checking pin;  
         [0022]    [0022]FIG. 4 is an exploded perspective view of a set pin showing a state where the continuity checking pin is assembled to a block section (encircled is an enlarged view);  
         [0023]    [0023]FIG. 5 is an exploded perspective view of the set pin showing a state where an insulating forward sleeve is assembled to the continuity checking pin;  
         [0024]    [0024]FIG. 6 is a sectional view showing a checking part of the connector continuity checking device (encircled is an enlarged view);  
         [0025]    [0025]FIG. 7 is a perspective view of a conventional connector continuity checking device; and  
         [0026]    [0026]FIG. 8 is a sectional view showing a state where a connector is engaged in the conventional connector continuity checking device to check continuity.  
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0027]    Now, one embodiment of the present invention will be described referring to the drawings.  
         [0028]    [0028]FIG. 1 is a sectional view of an essential part of a connector continuity checking device according to the embodiment of the present invention. FIG. 2 is a sectional view of the essential part in a state where a terminal is incompletely inserted in contrast with FIG. 1. The connector holding part and the driving mechanism of the checking part and so on are similar to those in the conventional case (see FIG. 7), and they are omitted from the drawings.  
         [0029]    In FIG. 1, numeral  31  represents a set pin of the connector continuity checking device, and numeral  32  represents a connector to be set on the connector continuity checking device.  
         [0030]    The set pin  31  is composed of a lance displacement detecting pin  34  made of metal and integrally projecting from a front end of a block section  33  made of metal in a rectangular shape, a pair of forward and rearward insulating sleeves  36 ,  37  made of synthetic resin which are press fitted in a bore  35  passing through the block section  33 , a continuity checking pin  38  made of metal and press fitted into an inner diameter part of the insulating sleeves  36 ,  37 .  
         [0031]    The insulating sleeves  36  and  37  are separately arranged in a longitudinal direction of the set pin  31 . In short, the forward insulating sleeve  36  is positioned at the front end of the block section  33  of the lance displacement detecting pin  34 , while the backward insulating sleeve  37  is positioned at the backward end of the block section  33 . The backward insulating sleeve  37  has an integral flange portion  39  which is adapted to be abutted against the backward end of the block section  33 . Respective lengths of the insulating sleeves  36 ,  37  are the same excluding the flange portion  39 , having a length of about one third of the block section  33 .  
         [0032]    The insulating sleeves  36 ,  37  are formed of strong engineering plastic material such as POM, etc. having a small thickness. In one example, the insulating sleeves  36 ,  37  are set to have a length of about 6 mm, and a thickness of about 0.4 mm. The insulating sleeves  36 ,  37 , the continuity checking pin  38 , and the block section  33  are fixed by press fitting. The continuity checking pin  38  is integrally provided, at its backward end, with a flange portion  40  which is adapted to be abutted against the flange portion  39  of the backward insulating sleeve  37 .  
         [0033]    Under a condition as shown in FIG. 1, a male terminal  41  has been completely inserted into the connector  32 . The connector  32  has been inserted into a checking part  42  (see FIG. 6) of the connector continuity checking device. The terminal  41  is locked by a lance  44  of the connector housing  43  formed of synthetic resin. The lance  44  is formed in a shape of an arm having flexibility. The terminal  41  has a body portion  46  to be contained in a terminal receiving chamber  45 , and a pin-like electrical contact portion  48  which projects from a distal end of the body portion  46  into a connector engaging chamber  47  of the checking part  42  (see FIG. 6). An electric wire  49  is press fitted to a backward end of the body portion  46 . The lance  44  has a projection  50  adjacent to its distal end which is adapted to be engaged in a hole in a forward end part of the body portion  46  to prevent withdrawal of the terminal  41 .  
         [0034]    In FIG. 1, the distal end portion of the lance displacement detecting pin  34  of the set pin  31  has entered into a flexing space  53  in the connector housing  43  through a front opening  51 . The distal end of the continuity checking pin  38  is in contact with a distal end of the electrical contact portion  48  of the terminal  41 . A backward end of the continuity checking pin  38  is in contact with a front end of a probe pin  53  (see FIG. 6). Presence of continuity is detected by an indication of a checker (not shown) which connects a lead wire  54  (see FIG. 6) of the probe pin  53  and the electric wire  49  of the terminal.  
         [0035]    A terminal receiving portion  55  in a concave conical shape presenting a V-shape in cross section is formed at the distal end of the continuity checking pin  38 . By providing the terminal receiving portion  55 , the distal end of the electrical contact portion  48  can be reliably caught. An inclination angle of the conical shaped terminal receiving portion  55  is set to be equal to an inclination angle of the distal end of the electrical contact portion  48  or more.  
         [0036]    In case where the electrical contact portion  48  is not in a columnar shape but a plate-like shape having a small width, the inclination angle of the conical shaped terminal receiving portion  55  is set to be equal to a larger one of the vertical or lateral inclination angles of the distal end of the electrical contact portion  48  or more. In this manner, the terminal receiving portion  55  is capable of corresponding to all the shapes of the electrical contact portion  48 . Moreover, the terminal receiving portion  55  may be formed as a recess in a barrel-like shape presenting a U-shape in cross section. Needless to say, by forming the terminal receiving portion  55  in the V- or U-shape in cross section, a wider guiding area for the electrical contact portion  48  can be obtained than with a simple recess.  
         [0037]    [0037]FIG. 2 shows a case where the terminal  41  has been incompletely inserted into the connector housing  43 . A lance receiving portion  56  in a U-shape in cross section is formed at the distal end of the lance displacement detecting pin  34  to a full extent of its width. The lance  44  is pressed by a bottom face of the terminal  41  and deflected in the flexing space  52 . When the distal end of the lance displacement detecting pin  34  is abutted against the distal end of the lance  44  for the check, there will be created a gap S between the distal end of the continuity checking pin  38  and the distal end of the electrical contact portion  48  of the terminal  41 , resulting in an NG (no continuity) of the insertion check. An abnormal condition, that is, incomplete insertion of the terminal  41  can be thus detected.  
         [0038]    Even in case where the lance displacement detecting pin  34  is abutted against the distal end of the lance  44 , and the lance displacement detecting pin  34  is apt to move with its speed and load, the lance displacement detecting pin  34  will not escape from the distal end of the lance  44 , because the distal end of the lance  44  has been inserted into the lance receiving portion  56 . It is to be noted that the lance receiving portion  56  may be in a form of a recess in a V-shape in cross section. By forming the lance receiving portion  56  in the V- or U-shape in cross section, a wider guiding area (wider in a direction of intersecting the above described width) for the distal end portion of the lance  44  can be obtained than with a simple recess.  
         [0039]    FIGS.  3  to  5  show steps of assembling the set pin  31  in order. At first, the first (backward) insulating sleeve  37  is pushed around the continuity checking pin  38  in a cylindrical shape from the front end and press fitted by a pushing jig (not shown). A press fitting allowance is about 0.1 mm in diameter. Then, as shown in FIG. 4, the backward insulating sleeve  37  is abutted against the flange portion  40  at the rear end of the continuity checking pin  38  and stopped there.  
         [0040]    In the next step, the continuity checking pin  38  is inserted into the bore  35  in the block section  33  of the lance displacement detecting pin  34 , until the backward insulating sleeve  37  is press fitted in the bore  35 . The press fitting work is conducted, for example, by tapping the backward end of the continuity checking pin  38  with a hammer. The bore  35  is formed so as to pass through the block section  33  in a longitudinal direction. The block section  33  is formed in a rectangular columnar shape, and from one side of its front end, the plate-like lance displacement detecting pin  34  is projected. The block section  33  is formed with a stepped portion  57  as a stopper for defining an advanced position of the set pin  31 .  
         [0041]    Then, as shown in FIG. 5, the forward end portion of the continuity checking pin  38  which has passed through the block section  33  projects forward from the front end of the block section  33 . The second (forward) insulating sleeve  36  in a cylindrical shape is press fitted into the bore  35  along the continuity checking pin  38 . A front end  58  of the forward insulating sleeve  36  is flush with a front end  59  of the block section  33 . The front end portion of the continuity checking pin  38  is positioned in parallel to the lance displacement detecting pin  34 .  
         [0042]    By employing a pair of the forward and backward insulating sleeves  36 ,  37  as shown in FIG. 1, the continuity checking pin  38  is accurately positioned and stably fixed in the block section  33 . Even though the continuity checking pin  38  is long sized, it can be supported at two positions in a longitudinal direction by means of a pair of the insulating sleeves  36  and  37 , and so, reliably prevented from wobbling, assuring a stable posture and uprightness.  
         [0043]    [0043]FIG. 6 shows the checking part  42  of the connector continuity checking device. In the checking part  42 , a plurality of the set pins  31  are inserted in and guided by guide holes  61  in a pin guide  60  formed of synthetic resin or metal to be engaged slidably in back and forth directions. Forward movement of each of the set pins  31  is restricted by the stepped portion  57  as shown in FIG. 4. Sliding portions  62  of the probe pins  53  are in contact with the backward ends of the continuity checking pins  38  and biased forward by means of coil springs (not shown) provided inside. Lead wires  54  are connected to backward ends of the probe pins  53 . Each of the set pins  31  can move back and forth independently, and the check of continuity and incomplete insertion of the terminal  41  (see FIG. 1) can be separately conducted with each of the set pins  31 .  
         [0044]    The pin guide  60  is fixed within a guide block  63  made of metal, and the probe pins  53  are fixed in a pin block  64  made of synthetic resin. The guide block  63  and the pin block  64  are fastened and fixed by means of bolts (not shown). The guide block  63  has the connector engaging chamber  47  at its front side, and a front end of the pin guide  60  is flush with a bottom wall  65  of the connector engaging chamber  47 . The lance displacement detecting pins  34  and the continuity checking pins  38  are projected into the connector engaging chamber  47 .  
         [0045]    Although the present invention has been fully described by way of examples referring to the accompanying drawings, it is to be noted that various changes and modifications will be apparent to those skilled in the art.