Abstract:
The compact steering column lock for a personal identification card system is provided to stably execute a conversion function of engaging or disengaging the maneuverability of a knob and a key interlock function and the like by receiving a control signal from a controller and a knob manipulation force from the user. The steering column lock for a personal identification card system comprises a bi-directional solenoid actuator, a lever, an actuating plate, a permanent magnet, a coil spring, and a cam shaft having a pivot axis, which is perpendicular to said pivot axis of said lever, the cam shaft including a cam whose pivot state is converted according to a pivot state of the blocking part of said lever.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   The present application is based on, and claims priority to, Korean Application Serial Number 10-2004-0078386, filed on Oct. 1, 2004, the disclosure of which is hereby incorporated by reference herein in its entirety. 
   FIELD 
   The present invention relates to a steering column lock for a Personal Identification Card (PIC) system. 
   BACKGROUND 
   Generally, a Personal Identification Card (PIC) system automatically releases a locked state of a vehicle when a user having an ID card approaches his or her vehicle and touches an outdoor handle. After entering the vehicle, the user can turn on the ignition of the engine by turning a knob formed at a steering column lock in the keyless PIC system vehicle. 
   The steering column lock used in the above PIC system is controlled by a controller that generates a control signal according to the proximity state of the ID card to the vehicle. The steering column lock includes an electromechanical mechanism, which automatically locks or releases the knob and the steering column. 
   SUMMARY OF THE INVENTION 
   Embodiments of the present invention are provided to stably execute a switching function of locking or releasing a knob and key interlock function and the like by receiving a control signal from a controller and a knob manipulation force from the user. 
   A steering column lock for a personal identification card system includes a bi-directional solenoid actuator that linearly shifts a plunger, which is protruded at a lateral side of the bi-directional solenoid actuator, to and from the bi-directional solenoid actuator. A lever includes a blocking part and a pivot axis, which is perpendicular to the linear movement direction of the plunger. The lever is resiliently supported to depress the plunger into a coil part of the bi-directional solenoid actuator by contacting a protruded end of the plunger. An actuating plate is integrally installed around the plunger. A permanent magnet is mounted between the actuating plate and coil part of the bi-directional solenoid actuator to provide a magnetic force to the actuating plate. A coil spring resiliently supports the actuating plate to distance the actuating plate from the permanent magnet. A cam shaft has a pivot axis, which is perpendicular to the pivot axis of the lever. The cam shaft also includes a cam of which pivot state is converted according to the pivot state of the blocking part of the lever. 

   
     For a better understanding of the nature and objects of the present invention, reference should be made to the following detailed description with the accompanying drawings, in which: 
       FIG. 1  is a schematic view of a steering column lock for a Personal Identification Card (PIC) system without a bi-directional solenoid actuator and the like, according to an embodiment of the present invention; 
       FIG. 2  illustrates an assembled state of a bi-directional solenoid actuator, permanent magnet and lever, which are removed in  FIG. 1 , in a base housing; 
       FIGS. 3A and 3B  comparatively delineates operation states of a plunger and lever; 
       FIGS. 4A and 4B  illustrate a LOCK state conversion mechanism via a cam and lever; 
       FIGS. 5A and 5B  depict a key interlock function; 
       FIGS. 6A and 6B  illustrate a mechanism to cope with an abnormal torque of a knob without re-operating a bi-directional solenoid actuator; 
       FIGS. 7A and 7B  illustrate a mechanism that can be converted into a LOCK state by pressing a knob only in an ACC state once the knob is in an ON or START state; 
       FIGS. 8A and 8B  illustrate a mechanism that detects whether a bi-directional solenoid actuator is normally operating; and 
       FIGS. 9A and 9B  illustrate a mechanism reinforced with a theft prevention function. 
   

   DETAILED DESCRIPTION OF THE EMBODIMENTS 
   Referring now to  FIGS. 1 to 4B , an embodiment of the present invention includes a bi-directional solenoid actuator  3  that linearly shifts a plunger  1 , which is protruded at a lateral side of bi-directional solenoid actuator  3 . A lever  9  has a blocking part  7  and a pivot axis, which is perpendicular to the linear movement direction of plunger  1 . Lever  9  is resiliently supported to depress plunger  1  into a coil part  5  of bi-directional solenoid actuator  3  by contacting a protruded end of plunger  1 . An actuating plate  11  is integrally installed around plunger  1 . A permanent magnet  13  is installed between actuating plate  11  and coil part  5  of bi-directional solenoid actuator  3  to provide a magnetic force to actuating plate  11 . A coil spring  15  resiliently supports actuating plate  11  to distance actuating plate  11  from permanent magnet  13 . A cam shaft  19  has a pivot axis, which is perpendicular to the pivot axis of lever  9 . Cam shaft  19  also includes a cam  17  of which pivot state is converted according to the pivot state of blocking part  7  of lever  9 . 
   Bi-directional solenoid actuator  3 , permanent magnet  13 , and lever  9  are assembled in a base housing  21  as illustrated in  FIG. 2 . Lever  9  is resiliently supported via a torsion spring  23  installed between base housing  21  and lever  9 . 
   With reference to  FIGS. 7A and 7B , a knob  25  is provided to receive a pivot manipulation force of the user. A cylinder  27  is installed between knob  25  and cam shaft  19  for transmitting the pivot force of knob  25  to cam shaft  19 . A cylinder spring  29  is inserted between cylinder  27  and cam shaft  19 . Cylinder spring  29  resiliently supports cylinder  27  and cam shaft  19  by pushing cylinder  27  and cam shaft  19  away from each other. A cylinder housing  31  encloses the outer circumference of cylinder  27  and guides a linear and pivot movement of cylinder  27 . 
   Cam shaft  19  is connected to an electrical switch part  33  to embody electrical states of Accessory (ACC), ON, and START according to the pivot state of cam shaft  19 . During the ACC state, power is provided to the accessory of the vehicle. The ON state maintains the activation of the engine and allows normal operation of the vehicle. The engine is cranked in the START state. 
   A LOCK state immobilizes the vehicle operation by preventing the pivot of knob  25 . Knob  25  according to the embodiment of the present invention can be converted from the LOCK state to the ACC state, ON state or START state by pivoting along the clockwise direction just like in typical vehicles. 
   A locking bar  35  is linearly and slidably installed for locking and unlocking a steering column by moving back and forth according to the pivot state of cam shaft  19 . A solenoid controller  37  controls bi-directional solenoid actuator  3  by receiving an encoded control signal from a controller (not shown) in response to the access state of the ID card to the vehicle. 
   Cam  17  is formed with a cam lock groove  39  into which blocking part  7  of lever  9  is inserted to form a LOCK state by restraining the pivot of cam shaft  19 . A cam operating groove  41  is formed on a trajectory of a circle formed by the rotation of cam lock groove  39  in relation to a central axis of cam shaft  19 . Cam operating groove  41  is formed to accommodate pivot displacements of ACC, ON and START states even if blocking part  7  of lever  9  is inserted into cam operating groove  41 . 
   Referring back to  FIGS. 7A and 7B , a cylinder nose  43  protrudes out from the circumferential surface of cylinder  27  in a radial direction of cylinder  27 . A cylinder lock groove  45  is opened towards cam shaft  19  at an inner side of cylinder housing  31  to form a LOCK state for insertion of cylinder nose  43 . A cylinder operating groove  47  is formed on a trajectory of a circle formed by the rotation of cylinder lock groove  45  in relation to a central axis of cylinder  27 . Cylinder operating groove  47  is formed in cylinder housing  31  to accommodate pivot displacements of cylinder nose  43  from the ACC state to ON state or START state even if cylinder nose  43  is inserted into cylinder operating groove  47 . A blocking lever  51  is installed at cylinder housing  31  and integrally equipped with a uni-directional blocking part  49  disposed between the ACC and ON states of cylinder operating groove  47  among trajectories of circles on which cylinder nose  43  can be pivoted while cylinder  27  is pushed down towards cam shaft  19  via knob  25 . Blocking lever  51  allows cylinder nose  43  to pivot only from ACC state to ON state in one direction. A blocking lever spring  53  resiliently supports blocking lever  51 . 
   Hereinafter, the expression “+X direction” refers to a direction of knob  25  being pushed towards cam shaft  19 , and “−X direction” refers to the opposite direction thereof. 
   As illustrated in  FIGS. 8A and 8B , an optical lever  59  is integrally connected to plunger  1  and is formed with a light penetrating part  55  and a light insulating part  57 . Light penetrating part  55  allows light to be penetrated in a perpendicular direction to the linear movement direction of plunger  1 , and light insulating part  57  insulates penetration of the light. An optical sensor  61  detects the variation of the light penetration state according to the linear movement of light penetrating part  55  and light insulating part  57 . 
   Optical sensor  61  is preferably installed at solenoid controller  37  as illustrated in the drawing. If actuating plate  11  is shifted to the −X direction, the light emitting from optical sensor  61  penetrates light penetrating part  55 , and if actuating plate  11  is shifted to the +X direction, light insulating part  57  isolates the light in the embodiment of the present invention. 
   Referring next to  FIGS. 9A and 9B , an impact lever  65  is installed to have a pivot shaft, which is perpendicular to the linear movement direction of plunger  1 . Pivot shaft of impact lever  65  is equipped at one end thereof with a weight  63  along a perpendicular direction to the linear movement direction of plunger  1 . The other end of pivot shaft of impact lever  65  pivots within the movement range of actuating plate  11 . Impact lever  65  is installed to push actuating plate  11  away from permanent magnet  13 . An impact lever spring  67  resiliently supports impact lever  65  at a place where the other end of impact lever  65  is in a deviated state from the movement range of actuating plate  11  to prevent any interruption with the movement of actuating plate  11 . The pivot shaft of impact lever  65  is supported at one end thereof by base housing  21  and at the other end by a fixing bracket  69  (see  FIGS. 9A and 9B ). 
   The operation of the embodiment of the present invention thus constructed will now be described in detail. 
   Two operation states of plunger  1  and lever  9  are comparatively delineated in  FIGS. 3A and 3B . In the upper drawing, cam  17  of cam shaft  19  and lever  9  may be interrupted with each other. If lever  9  is inserted into cam lock groove  39 , cam  17  cannot rotate in any direction and a LOCK state is formed. If lever  9  is inserted into cam operating groove  41 , cam  17  can pivot only between the ACC and START states. In the lower drawing, cam  17  can rotate in any direction without being affected by lever  9 . 
   The upper state of  FIG. 3A  is maintained when Force (F EM1L1 ) from coil part  5  of bi-directional solenoid actuator  3  is not provided. Force (F S2L1 ) of coil spring  15  is more powerful than the resultant force of Force (F S1a1 ) of torsion spring  23  and Force (F PML1 ) applied to actuating plate  11  via permanent magnet  13 . Plunge  1  receives force towards the −X direction. If Force (F EM1L1 ) is applied to coil part  5 , plunger  1  overcomes Force (F S2L1 ) of coil spring  15  and shifts toward the +X direction to form the lower state of  FIG. 3B . 
   The lower state of  FIG. 3B  is constantly maintained when Force (F EML2L2 ) from coil part  5  is not applied. Force (F S2L2 ) of coil spring  15  is more powerful than the resultant force of Force (F s1a2 ) of torsion spring  23  and Force (F PML2 ) applied to actuating plate  11  via permanent magnet  13 . Plunge  1  receives force towards the +X direction. If Force (F EM2L2 ) is applied to coil part  5 , plunger  1  overcomes Force (F s1a2 ) of torsion spring  23  as well as Force (F PML2 ) of permanent magnet  13  and shifts toward the −X direction to form the upper state of the drawing. 
   Plunger  1  is converted into the upper or lower state of  FIGS. 3A and 3B  depending on the force applied to coil part  5  of bi-directional solenoid actuator  3 . The converted state of plunger  1  is maintained until an opposite force to the previous operation via coil part  5  is applied. 
   In reference to  FIGS. 4A and 4B , once blocking part  7  of lever  9  is inserted into cam lock groove  39  of cam  17 , cam shaft  19  cannot pivot in any direction. A LOCK state of the vehicle is formed in the left drawing and knob  25  connected to cam shaft  19  via cylinder  27  is prevented from being pivoted. 
   Provided that a controller transmits an encoded signal to solenoid controller  37  after verifying a ride of the driver, solenoid controller  37  shifts plunger  1  toward the +X direction by manipulating coil part  5 . The right state of  FIG. 4  is formed and the LOCK state is released, allowing cam  17  to rotate. 
   When the vehicle has come to a halt and the user has finished driving, if the user turns knob  25  from ACC state back to the LOCK state, solenoid controller  37  shifts plunger  1  toward the −X direction by receiving a signal from the controller. Blocking part  7  of lever  9  is inserted into cam lock groove  39 , thereby preventing knob  25  from pivoting. 
     FIG. 5A  illustrates cam  17  in an ACC state. If knob  25  is pivoted from the right state of  FIG. 4  to one of ACC, ON or START state by a user and a shift lever is shifted to any range except for PARK, the controller shifts plunger  1  toward the −X direction through solenoid controller  37 , and blocking part  7  of lever  9  is inserted into cam operating groove  41 . Knob  25  can now be pivoted by the driver between the ACC state and START state but restrained in pivot to the LOCK state, thereby embodying a key interlock function. 
   In order to turn knob  25  to the LOCK state from the above state, the shift lever should be in the PARK range. If the driver shifts the shift lever to PARK from the left state of  FIG. 5A , the controller controls solenoid controller  37  to move plunger  1  to the +X direction such that lever  9  is converted as illustrated in the right state of  FIG. 5B , and cam  17  can pivot into the LOCK state. 
     FIGS. 6A and 6B  depict a mechanism to cope against a potential abnormal torque occurrence when releasing the LOCK state of knob  25  or a key interlock function. When the manipulation of knob  25  by the driver is executed before solenoid controller  37  controls plunger  1  to move toward the +X direction by receiving an encoded signal from the controller, lever  9  does not pivot normally by the force of torsion spring  23  and only plunger  1  moves toward the +X direction due to an engagement of blocking part  7  and cam  17  (see left drawing in  FIG. 6A ). 
   When knob  25  is not pivoted to a desired direction in the above case, if the driver re-pivots knob  25  after a certain period of time, lever  9  pivots at the above certain delay moment by the force of torsion spring  23  (just like the right state of  FIG. 6B ), then the driver can perform a desired manipulation. A simplified control logic is performed in the above state without re-activating bi-directional solenoid actuator  3  in the present invention. 
   After knob  25  is pivoted into the ON or START state, knob  25  can be converted from ACC state to LOCK state only when knob  25  is pushed toward the +X direction (see  FIGS. 7A and 7B ), thereby improving stability of the vehicle and fulfilling the vehicle safety rules. 
   While knob  25  is being pushed under the ACC state (right state of  FIG. 7A ), knob  25  can be turned in either the counterclockwise direction to the LOCK state or the clockwise direction to the ON or START state as blocking lever  51  can pivot in the counterclockwise direction. 
   Blocking lever  51  cannot pivot in the clockwise direction. Therefore, the ON state cannot be converted into the ACC state while knob  25  is being pushed. Thus, the driver can pivot knob  25  from the ON state to ACC state only if knob  25  is not pressed. In short, knob  25  can be converted into the LOCK state only after passing through the left state of  FIG. 7 . 
   In order to pivot knob  25  into the LOCK state from the left ACC state of  FIG. 7A , knob  25  should be re-pressed and turned in the counterclockwise direction. 
   Once knob  25  is either in the ON or START state, the driver should pivot knob  25  in the counterclockwise direction for conversion into the ACC state. Then, knob  25  should be pressed and pivoted further in the counterclockwise direction to be converted into the LOCK state. 
   In case the key interlock function is not performed due to an abnormal operation of bi-directional solenoid actuator  3  with electrical or electronical problems, the driver can turn knob  25  to the LOCK state by pressing knob  25  toward the +X direction in the ACC state irregardless of the shift lever being shifted to PARK. Hence, vehicle stability is obtained and rules for vehicle safety are satisfied. 
   While driving at a high speed with a shift lever in the range of DRIVE, knob  25  can be converted into the LOCK state only by pushing knob  25  at the ACC state. This ensures the driver&#39;s intention to lock the steering column. 
   In  FIGS. 8A and 8B , whether bi-directional solenoid actuator  3  is precisely controlled in accordance with the control intention is checked by monitoring the disposition of plunger  1  via optical lever  59  and optical sensor  61 , thereby improving the reliability of the operation of the steering column lock. 
   In the left drawing of  FIG. 8A , plunger  1  is maximally shifted to the −X direction such that blocking part  7  of lever  9  can restrain the pivot movement of cam  17 . Light insulating part  57  of optical lever  59  that integrally moves with plunger  1  is detected via optical sensor  61 . In the right drawing, plunger  1  shifts to the +X direction so that blocking part  7  of lever  9  allows the rotation of cam  17 . Light penetrating part  55  of optical lever  59  integrally moving with plunger  1  is detected via optical sensor  61 . 
   Controller or solenoid controller  37  checks whether bi-directional solenoid actuator  3  is controlled as desired via a signal from optical sensor  61 , and then re-operates bi-directional solenoid actuator  3  if necessary, thereby greatly improving the reliability of the operation of the steering column lock. 
   The left state in  FIG. 9A  illustrates a normal LOCK state of the steering column lock, and the right state thereof illustrates when external impact is applied. 
   Weight  63  of impact lever  65  receives force towards the +X direction as plunger  1  tends to move towards +X direction by the external impact. Impact lever  65  pivots in the clockwise direction and pushes actuating plate  11  to the −X direction, resulting in a restraint of plunger  1  from moving towards the +X direction. 
   When acceleration (a) through the external impact is applied to the steering column lock, Force (F M′P′ ) applied to actuating plate  11  as impact lever  65  pivots by Force (F MP ) applied to weight  63  should be greater than the resultant force of Force (F L1a1 ) of torsion spring  23  as well as Force (FPL) of plunger  1  received by the acceleration (a). Therefore, sufficient mass for weight  63  should be formed. Plunger  1  is restrained from moving upon exterior impact, thereby reinforcing a theft prevention function. 
   As apparent from the foregoing, there is an advantage in that a LOCK state conversion of the knob and a key interlock function are performed by one bi-directional solenoid actuator conventionally requiring two solenoid actuators, thereby reducing the number of components, weight, volume of the vehicle and manufacturing costs. The control logic of the controller or solenoid controller is also simplified. 
   The bi-directional solenoid actuator of the present invention has two static dispositions and completes its operation by using a short electrical pulse while the plunger is in operation, and the coil part of the bi-directional solenoid actuator is not required to be operated for a long period of time, thereby increasing the durability of the bi-directional solenoid actuator. A plunger having a relatively light weight is used in the embodiment of the present invention, reducing the operation noise. 
   The bi-directional solenoid actuator activated only by a short electrical pulse is prevented from a premature discharge of the battery. Even if the shift lever is in the PARK range for a long period of time with the knob in the ACC state, the key interlock function is completely embodied by single pulse applied to the bi-directional solenoid actuator, thus preventing a continuous battery discharge. 
   Further, even if the lever is abnormally restricted in movement due to the pivot manipulation of the driver applied before the operation of the plunger, the lever can normally operate without re-activating the bi-directional solenoid actuator by the separate configuration of the plunger and lever and by the certain delay period of time of the pivot manipulation of the driver. 
   Furthermore, in case the key interlock function is not properly executed by an abnormal operation of the bi-directional solenoid actuator due to electrical or electronical problems, the knob should be pressed in the ACC state to be converted into the LOCK state, thereby improving the stability of the vehicle and carrying out the vehicle safety rules.