Abstract:
In a door closer device which requires at least three switches consisting of a half door detection switch, a full lock (completely closing) detection switch and a switch for detecting the return to the initial position, the number of switches can be reduced. Two cam switch operating portions are formed on a cam plate fixedly secured to an output shaft of a motor. The motor is stopped by making use of one operating portion and the motor is rotated in a reverse direction by making use of the other operating portion.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates to a door lock device for motor vehicles which can automatically operate a door in an incompletely closed (half-latch) position to a completely closed (full-latch) position. 
     The completely closed (full-latch) condition of a door of a vehicle can be obtained by engaging a striker which constitutes a body-side member of the vehicle with a latch which constitutes a portion of a door lock device provided on a back door or a side door. As shown in FIG. 8, the latch  1  is disposed rotatably about a pin  2  and is always forcibly directed in one direction by receiving a biasing force of a spring  3 . The latch  1  includes an engaging groove  5  which receives a striker  4 , a first pawl receiving portion  6  which is formed on the periphery of the latch  1  and establishes the door completely closed (full-latch) condition, and a second pawl receiving portion  7  which establishes the door incompletely closed (half-latch) condition. A protrusion  9  of a pawl  8  is engageable with one of both the pawl portions  6 ,  7 . 
     The pawl  8  is rotatable about a pin  9 ′ which works as the center of rotation and the pawl  8  is always forcibly rotated in a direction toward the latch  1  by means of a spring  10 . The pawl  8  is movable in the counter-clockwise direction corresponding to the movement of a pin  11  of a lift lever which belongs to an open system of a door lock device. 
     In the door opened condition or position, the engaging groove  5  is rotated in the right direction as seen in FIG.  8  and the protrusion  9  of the pawl  8  comes into contact with an outer peripheral surface  12  of the latch  1 . Upon the door closing manipulation, the striker  4  enters the inside of the engaging groove  5  and forcibly rotates the latch  1  in the counter-clockwise direction and hence, the protrusion  9  is engaged with the second pawl receiving portion  7  to establish the incompletely closed (half-latch) condition, that is, the incompletely latched condition of the door. Upon the further door closing manipulation, the protrusion  9  is engaged with the first pawl receiving portion  6  so as to establish the completely closed (full-latch) condition, that is, the completely latched condition (condition shown in FIG.  8 ). 
     In the above-mentioned door closing manipulation, when the manipulation force is weak or the like, a case that the door closing manipulation ends with the protrusion  9  of the pawl  8  held in the incompletely closed condition in which the protrusion  9  of the pawl  8  is engaged with the second pawl receiving portion  7  may arise. Then, the door in the incompletely closed (half-latch) condition is automatically shifted to the completely closed (full-latch) condition by means of a door closer mechanism. 
     Examples of this type of door closer are disclosed in Japanese Patent Laid-Open Publication No. 96079/1990, Japanese Patent Laid-Open Publication No. 50045/1994 or Japanese Patent Publication No. 2816804/1999. 
     In the conventional door closer device, at least three switches consisting of a half-latch detection switch, an overlock (full-latch) detection switch and an initial position detection switch are arranged. In response to signals outputted from these switches, manipulations consisting of the start of pulling operation, the start of reverse operation to return a passive lever to the initial position, and the completion of the operation due to the detection of returning of the passive lever to the initial position and the stop of a motor are carried out. 
     However, the preparation and the mounting of three switches bring about drawbacks that the assembling operation becomes difficult and the device becomes large-sized. 
     SUMMARY OF THE INVENTION 
     Accordingly, it is an object of the present invention to provide a door lock device which can overcome the drawbacks of the above-mentioned prior art. 
     To overcome the above-mentioned drawbacks, the present invention adopts basic technical steps that a cam plate having a pair of signal generating portions is mounted on a motor output shaft and a cam switch having a contact member which comes into contact with each of these signal generating portions is combined with the cam plate. 
     To be more specific, the present invention provides a door lock device which includes a bracket which has a fixed relationship relative to a door panel, a door lock which includes a latch, a pawl and a latch lever which is fixedly secured to a rotary shaft of the latch, a passive lever which is rotatably supported relative to the bracket and includes a free end portion which is capable of coming into contact with the latch lever, a drive source which is retained by the bracket and mounts a cam plate on an output shaft thereof and is interlocked with the passive lever, a cam switch which has a contact member coming into contact with the cam plate and has a fixed relationship relative to the bracket, and a half latch switch which detects a door incompletely (half) latched condition of a latch which constitutes a door lock, wherein the cam plate includes a motor stop signal generating portion and a motor reverse rotation signal generating portion. 
     Upon the normal rotation of the motor, the passive lever is rotated by way of the cam plate to establish the door completely (fully) latched condition and simultaneously the signal generating portion of the cam plate outputs a signal to make the motor rotated in the reverse direction so as to return the passive lever to the initial position. Accordingly, two signals are outputted with one cam plate so that at least one switch can be eliminated. 
     These and other objects and advantages of the present invention will become further apparent from the following detailed explanation. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a front view of a door lock device of one embodiment of the present invention; 
     FIG. 2 is a cross-sectional view as taken along an arrow II—II of FIG. 1; 
     FIG. 3 is a plan view showing the door lock; 
     FIG. 4 is a cross-sectional view as taken along an arrow IV—IV of FIG. 1; 
     FIG. 5 is an operational view showing the movement of the motor and various switches in the door opened or closed conditions; 
     FIG. 6 is a front view showing the initial position of the passive lever; 
     FIG. 7 is a front view showing the condition where the free end portion of the passive lever comes into contact with the latch lever; and 
     FIG. 8 is a plan view showing the movement of the latch and the pawl. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Embodiments of the present invention are explained hereinafter in conjunction with attached drawings. 
     As shown in FIG.  1  and FIG. 2, a door closer device  13  includes a base plate  16  which is fixedly secured to a door inner panel  14  with the use of a bolt  15  and a motor bracket  17 . A door lock  18  is supported on the base plate  16  and a passive lever  21  is rotatably supported on the motor bracket  17  having a shape which traces an indoor trim  38  with the use of a bolt  19  and a nut  20 . The rotation of the passive lever  21  about the bolt  19  which works as the center of rotation is guided by a pin  23  which projects from the motor bracket  17  and passes through an elongated hole  22  formed in the passive lever  21 . 
     As shown in FIG. 3, the door lock  18  includes a latch  1  and a pawl  8  as its basic constitution (refer to FIG.  8 ). Although the door lock  18  has substantially the same constitution as that shown in FIG. 6, in addition to the constitution shown in FIG. 6, the door lock  18  includes a half latch switch  24 . When the door becomes the incompletely (half) latched condition in which a protrusion  9  of the pawl  8  is engaged with a second pawl receiving portion  7  of the latch  1  upon the door closing operation, the half latch switch  24  outputs an electric signal which indicates that the door is in the incompletely (half) latched condition. 
     A latch lever  25  is fixedly secured to the pin  2  of the latch  1 . The fan-shaped latch lever  25  has a proximal side one end thereof fixedly secured to the pin  2  and is provided with a protrusion  26  at a free end portion thereof. 
     A free end portion  27  formed on one end of the passive lever  21  is made to face the protrusion  26  of the latch lever  25  in an opposed manner. 
     As shown in FIG. 1, the passive lever  21  is made of a thin elongated plate and has an elongated slot  40  at a left side portion thereof. The passive lever  21  is rotatable about the bolt  19  which works as the center of rotation. 
     A motor  29  equipped with a speed reduction mechanism  28  is held by a motor bracket  17  which is supported on the door inner panel  14 . A cam plate  31  is fixedly secured to an output shaft  30  of the speed reduction mechanism  28 . 
     The cam plate  31  consists of a semicircular portion  32  which sets its center of rotation as the center of curvature, a small arcuate portion  33  which has the curvature smaller than the curvature of the semicircular portion  32  and is positioned at the opposite side relative to the semicircular portion  32 , and a pair of straight portions  34  which connect terminal ends of the semicircular portion  32  and the small arcuate portion  33 . 
     As shown in FIG. 4, a drive bolt  35  is screwed into one terminal end portion of the semicircular portion  32  of the cam plate  31  through the slot  40  formed in the passive lever  21 . 
     A cam switch  36  having a contact point which comes into contact with the outer peripheral surface of the cam plate  31  is supported on a cam switch bracket  37 . The cam switch bracket  37  is fixedly secured to the motor bracket  17  by screws. Upon receiving a signal from this cam switch  36 , the motor  29  is rotated in the normal direction or in the reverse direction. 
     FIG. 5 shows the ON condition, the OFF condition, the normal rotation condition and the reverse rotation condition of the half latch switch  24 , the cam switch  36  and the motor  29  when the door is opened, when the door is in the half door condition (in the incompletely (half) latched condition) and when the door is completely closed (in the completely (fully) latched condition). 
     During the door closing operation, when the half latch switch  24  (see FIG. 3) detects the incompletely (half) latched condition in which the pawl portion  9  of the pawl  8  is engaged with the second pawl receiving portion  7  of the latch (see FIG.  8 ), a detection signal is transmitted to the motor  29  so as to rotate the motor  29  in the normal direction. Here, as shown in FIG. 6, although the contact member of the cam switch  36  comes into contact with an A portion of the cam plate  31 , due to the rotation of the motor  29  in the normal direction (clockwise direction as seen in FIG.  6 ), the contact member of the cam switch  36  comes into contact with the outer peripheral surface of the semicircular portion  32  of the cam plate  31  and maintains the rotation of the motor  29  in the normal direction. 
     The further rotation of the motor  29  in the normal direction brings the contact member of the cam switch  36  into contact with a B portion of the cam plate  31  as shown in FIG.  7 . When the contact member comes into contact with the B portion (see FIG.  7 ), the cam switch  36  transmits a signal to the motor  29  so as to stop the motor  29  and to rotate the motor  29  in the reverse direction. The rotation of the motor  29  in the reverse direction soon brings the above-mentioned contact member into contact with the A portion of the cam plate  31 . Due to this contact, the cam switch  36  outputs a motor stop signal so as to stop the motor  29 . That is, the motor  29  returns to the initial position and maintains the initial position shown in FIG. 6 until the motor  29  receives a signal from the half latch switch  24 . 
     As shown in FIG.  6  and FIG. 7, the rotation of the motor  29  in the normal direction rotates the passive lever  21  in the clockwise direction about the bolt  19  which works as the center of rotation. This movement is produced as the bolt  35  moves in and along the slot  40  corresponding to the rotation of the cam plate  31 . 
     At the point of time that the contact member of the cam switch  36  comes into contact with the B portion of the cam plate  31 , the free end portion  27  of the passive lever  21  pushes the latch lever  25  so as to establish the completely (fully) closed condition, that is, the completely (fully) latched condition of the door. After establishing this completely (fully) latched condition, corresponding to the rotation of the motor  29  in the reverse direction, the passive lever  21  returns to the initial position (see FIG. 6) where the free end portion  27  of the passive lever  21  is moved away from the latch lever  25 . 
     The contacting of the contact member of the cam switch  36  to the A portion of the cam plate  31  makes the cam switch  36  output the signal to stop the motor  29  and the contacting of the contact member of the cam switch  36  to the B portion of the cam plate  31  makes the cam switch  36  output the signal to rotate the motor  29  in the reverse direction. 
     This makes it possible to perform the following controls. That is, for example, when the malfunction occurs in the midst of the movement from A to B of the cam switch of FIG. 5, the control is performed such that the motor  29  is rotated in the reverse direction upon receiving the signal corresponding to the B portion to return the cam switch to the A portion and then the motor  29  is stopped, while when the malfunction occurs in the midst of the movement from B to A of the cam switch of FIG. 5, the control is performed such that the motor  29  continues its operation to obtain a motor stop signal which is outputted when the A portion comes into contact with the contact member of the cam switch  36 . 
     As many apparently widely different embodiments of the present invention can be made without departing from the spirit and scope thereof, it is to be understood that the invention is not limited to the specific embodiments thereof except as defined in the appended claims.