Abstract:
A door lock system for a vehicle includes a latch mechanism, a link mechanism and a housing. The latch mechanism is adapted to a vehicle door and latches the vehicle door to a vehicle body. The link mechanism includes an electric driving source and a plurality of lever members for selectively locking and unlocking the latch mechanism. The housing accommodates the latch mechanism and the link mechanism.

Description:
[0001]    This application is based on and claims priority under 35 U.S.C. §119 with respect to Japanese Patent Application No. 2000-075960 filed Mar. 17, 2000, the entire contents of which is herein incorporated by reference.  
         BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    This invention relates to a door lock system for a vehicle.  
           [0004]    2. Description of Related Arts  
           [0005]    A type of door lock system for a vehicle is proposed in a Japanese Patent Publication H7-103735 published on Nov. 8, 1995. The door lock system for the vehicle comprises a) a latch mechanism including a latch which is provided in a vehicle door and which engages a striker secured to a vehicle body, and b) a link mechanism-including plurality of lever members and an electric actuator member for selectively locking or unlocking the engagement between the latch and the striker.  
           [0006]    In the above door lock system for the vehicle, all structural members of the link mechanism of the door lock system are supported by a base plate disposed in the door. Some of the structural members of the link mechanism are accommodated within the base plate, but other members are exposed outside of the base plate. Thus, the members exposed outside of the base plate may be operated from the outside of the vehicle through a gap between the door and the body of the vehicle. In this case, the door lock may be unlocked thereby allowing the door to be opened. In addition, the structure members of the link mechanism exposed outside of the base plate may be exposed to water which can enter the door.  
           [0007]    To overcome the above problems, a protector is provided on the base plate for accommodating the structural members, which are exposed outside of the base plate, within the protector. However, the protector has to be added from outside as an additional member of the link mechanism, whereby the manufacturing cost, labor for assembling and the number of members are increased. Furthermore, the door lock system, as a whole, is oversized. Accordingly, it is preferable to accommodate all structural members within the closed housing.  
           [0008]    In this case, a problem in determining how compactly the structural members, which are exposed outside of the base plate, can be accommodated in the closed housing. A main member exposed outside of the base plate is the electric actuator member, which is large in size compared to the other structural members. Thus, it becomes a more serious problem to compactly structure the connecting portion between an output portion of the electric actuator member and an operating means which selectively locks or unlocks the engagement of the latch mechanism within the closed housing.  
         SUMMARY OF THE INVENTION  
         [0009]    It is, therefore, necessary for a door lock system to address at least the foregoing drawbacks of the related art.  
           [0010]    According to the present invention, the door lock system for a vehicle includes a) a latch mechanism which is adapted to a vehicle door and which holds or latches the vehicle door to a vehicle body, b) a link mechanism including an electric driving source and a plurality of lever members for selectively locking and unlocking the latch mechanism, c) a housing accommodating the latch mechanism and the link mechanism.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]    These and other objects of the invention will become more apparent from the following embodiments of the invention with reference to the attached drawings in which:  
         [0012]    [0012]FIG. 1 shows an exploded perspective view of a door lock device of an embodiment of this invention;  
         [0013]    [0013]FIG. 2 shows an enlarged perspective view of one part of FIG. 1;  
         [0014]    [0014]FIG. 3 shows an enlarged perspective view of the other part of FIG. 1;  
         [0015]    [0015]FIG. 4 shows a vertical cross-sectional view of a part of the door lock system;  
         [0016]    [0016]FIG. 5 shows a vertical cross-sectional view of FIG. 4 taken along the lines V-V;  
         [0017]    [0017]FIG. 6 shows a horizontal cross-sectional view of FIG. 4 taken along the lines VI-VI;  
         [0018]    [0018]FIG. 7 shows a side view of structural members of the door lock system in an unlocked stage;  
         [0019]    [0019]FIG. 8 shows a side view of an inside of the door lock system in an locked state;  
         [0020]    [0020]FIG. 9 shows a side view of the inside of the door lock system which is in the unlocked state when an outside handle is operated;  
         [0021]    [0021]FIG. 10 shows a side view of the inside of the door lock system in a locked state when the inside or outside handle is operated;  
         [0022]    [0022]FIG. 11 shows a side view of the inside of the door lock system in a canceling operation;  
         [0023]    [0023]FIG. 12 shows a side view of the inside of the door lock system in a keyless locking operation; and  
         [0024]    [0024]FIG. 13 shows a side view of the inside of the door lock system in a one-motion operation.  
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0025]    An embodiment of this invention will be described below referring to FIGS.  1 - 8 . Each direction of the arrows in FIG. 1 indicates longitudinal, vertical and width directions of the vehicle.  
         [0026]    The door lock system is disposed within a door of the vehicle, and is formed to accommodate a first link mechanism  20  and a second link mechanism  30  in a housing  10  (see FIG. 4). The housing  10  comprises a main body  11 , a first cover  12  and a second cover  13 . The main body  11  includes a) a first casing portion  11   a  (see FIG. 2) which has a dish shape open to the vehicle inside direction and b) a second casing portion  11   b  (see FIG. 2) which has a dish shape perpendicular to the first casing portion  11   a  and which is open to the vehicle back side direction. The first casing portion  11   a  and the second casing portion  11   b  are integrally formed therewith. The first cover  12  is attached to the first casing portion  11   a  at the opening side thereof. The second cover  13  is attached to the second casing portion  11   b  at the opening side thereof. Thus, the opening of the first casing portion  11   a  is closed by the first cover  12 , and the opening of the first casing  11   b  is closed by the second cover  13 .  
         [0027]    In the housing  10 , both a) an electric distribution plate  14  which is electrically connected to an electric motor  25  acting as an actuator and b) structural members of the first link mechanism  20  are disposed so as to be accommodated between the first casing portion  11   a  and the first cover  12 . A sub base plate  15  and structural members of the second link mechanism  30  are accommodated between the second casing portion  11   b  and the second cover  13 . A base plate  16  is attached to the second cover  13  at an opening side thereof. Thus, the opening of the second cover  13  is closed and covered by the base plate  16 . Each structural member of a latch mechanism  40  is accommodated between the inside of the second cover  13  and the base plate  16 .  
         [0028]    A first inside lever  21  is rotatably supported on the inside of the first cover  12  by a supporting pin  21   a  (see FIG. 2) so as to be rotatably movable in vertical and longitudinal directions of the vehicle. A second inside lever  51  is rotatably supported on the outside of the first cover  12  by the supporting pin  21   a  so as to be rotatably movable in vertical and longitudinal directions of the vehicle. The first inside lever  21  has an engaging projection  21   b  (see FIG. 2) which extends in the vehicle inside direction through a sector-shaped hole  12   a  formed in the first cover  12 . The engaging portion  21   b  of the first inside lever  21  engages with a connecting hole  51   a , whereby the engaging projection  21   b  connects the first inside lever to the second inside lever  51  as one unit. The first inside lever  21  has an engaging projection  21   c  which extends in the vehicle outside direction. When the first inside lever  21  is rotated in a clockwise direction as shown in FIG. 8, the engaging projection  21   c  engages with a canceling lever  22 . The canceling lever  22  is then rotated.  
         [0029]    The second inside lever  51  is connected with an inside cable  52  which is connected with an inside handle (not shown) disposed inside of the vehicle. The rotation of the inside handle in a door opening direction (the operation for opening the door using the inside handle) causes the second inside lever  51  to rotate in a clockwise-direction as indicated in FIG. 1, FIG. 2 and FIG. 7, thereby rotating the first inside lever  21  in the same direction.  
         [0030]    The canceling lever  22  is rotatably supported at the inside of the first cover  12  by a supporting pin  22   a  formed integrally with the first cover  12 . The canceling lever  22  is provided adjacent the first inside lever  21  in the vehicle outside direction to be parallel to the first inside lever  21 . The canceling lever  22  has an engaging pin  22   b  which extends in the vehicle outside direction. The engaging pin  22   b  is inserted into a first engaging groove  23   a  which is formed as a V-shaped slot. The groove  23   a  is formed in an open link  23  which is disposed adjacent the canceling lever  22  in the vehicle outside direction.  
         [0031]    The open link  23  has an elongated second engaging groove  23   b  wherein an engaging pin  27   b  of an active lever  27  is inserted. An engaging portion  23   c , which is formed as a L-shaped plate, engages with an end of the first inside lever  21 . A connecting portion  23   d  connects the open link  23  to an opening lever  31 . The open link  23  is supported by the canceling lever  22 , the active lever  27  and the opening lever  31 .  
         [0032]    The locking lever  24  is rotatably supported on an inside of the first casing portion  11   a  by a supporting pin  24   c  (FIG. 4) formed integrally with the main body  11  to be rotatably movable in the vertical and longitudinal directions of the vehicle. The locking lever  24  is provided in parallel with the open link  23 . The locking lever  24  has an attachment hole  24   a  which is fixed to a locking cable  53 . An elongated engaging groove  24   b  has inserted therein an engaging pin  27   b  of the active lever  27 . The locking cable  53  is connected with a locking knob (not shown) which is disposed on an inside of a door of the vehicle. When the locking knob is operated for locking the door, the locking cable  53  transmits an operation force from the locking knob to the locking lever  24 , thereby rotating the locking lever  24  in the clockwise direction as shown in FIG. 1.  
         [0033]    The electric motor  25  generates the operation force for moving the first link mechanism  20 . The electric motor  25  is attached to the inside of the first cover  12 . The electric motor  25  includes a worm gear  25   a  at an output shaft of the electric motor  25 . The worm gear  25   a  is in mesh engagement with a wheel gear  26 . The wheel gear  26  has a pair of engaging pins  26   a ,  26   b  on an outside thereof. The wheel gear  26  is rotatably supported on the inside of the first cover  12  by a supporting boss  26   c  formed integrally with the first cover  12 . Both engaging pins  26   a  and  26   b  are arranged at both sides of the rotational center of the wheel  26  in the longitudinal direction of the vehicle such that a predetermined space is defined between engaging pins  26   a  and  26   b . Either engaging pin  26   a  or  26   b  extends into an engaging concave portion  27   c  of the active lever  27 .  
         [0034]    The active lever  27  is disposed between the wheel gear  26  and the open link  23 . The active lever  27  is rotatably supported on the inside of the first cover  12  by a supporting boss  27   f  formed integrally with the first cover  12 . The active lever  27  includes a main lever portion  27   a , a projecting portion  27   d  having a spring function and a rubber cushion  27   e . The main lever portion  27   a  has the engaging pin  27   b  projecting in the vehicle outside direction and an engaging concave portion  27   c  opening in a vehicle inside direction. The projecting portion  27   d  is provided at an upper end of the main lever portion  27   a . The rubber cushion  27   e  is disposed on the portion between the main lever portion  27   a  and the projecting portion  27   d . The engaging pin  27   b  of the active lever  27  extends through the second engaging groove  23   b  of the open link  23  and the engaging groove  24   b  of the locking lever  24 . The engaging concave portion  27   c  of the active lever  27  has either engaging pins  26   a  or  26   b  extending thereinto. An end of the projecting portion  27   d  of the active lever  27  elastically contacts an inner periphery of the first cover  12 . The engaging concave portion  27   c  of the active lever  27  is formed so that either the front engaging pin  26   a  or the rear engaging pin  26   b  can be engaged with the active lever  27  when the wheel gear  26  is rotated in either the normal or the reverse directions. The active layer  27  can be rotated in either the clockwise direction or the counter-clockwise direction as shown in FIGS. 7 and 8. The end of the projecting portion  27   d  slidably moves on the inner periphery of the first cover  12  and selectively engages with either of these engaging concave portions  12   b  or  12   c  (FIG. 7). The rubber cushion  27   e  selectively contacts either stopper portions  11   c  or  11   d  in accordance with the above motion of the projecting portion  27   d.    
         [0035]    A key lever  28  has a cylinder-shaped main body  28   a  and a lever port ion  28   b  formed integrally with the cylinder-shaped main body  28   a . The key lever  28  and an idle lever  29  are rotatably supported by a supporting boss  28   e  (see FIG. 2) formed integrally with the first casing portion  11   a  and a supporting boss  28   f  formed integrally with the first cover  12 . The key lever  28  has an engaging groove  28   c  provided in the main body  28   a  and an engaging pin  28   d  provided on the lever portion  28   b  at the opposite side thereof (FIG. 2). An end of a projecting pin of a key cylinder (not shown), which is disposed on the outside of the door, is disposed into the engaging groove  28   c . The engaging pin  28   d  extends into a sector-shaped engaging groove  29   a  formed in the idle lever  29 . The key lever  28  is rotated by the rotation of the key cylinder turned by a key (not shown). The key lever  28  rotates the idle lever  29  via the engaging pin  28   d . Then, the idle lever  29  selectively rotates the active lever  27  in the clockwise direction or the counter-clockwise direction (as indicated in FIGS. 7 and 8) via a connecting pin  29   b  formed integrally with the idle lever  29 .  
         [0036]    Each structural member of the second link mechanism  30  is accommodated between the second casing portion  11   b  of the main body  11  and the second cover  13  as shown in FIG. 3. The opening lever  31  of the second link mechanism  30  is rotatably supported on the second casing portion  11   b  and the sub base plate  15  by a supporting pin  31   a  via a torsion spring  31   b . The opening lever  31  is rotatably movable in vertical and width directions of the vehicle between the second casing portion  11   b  and the sub base plate  15 . A rotating end  31   c  of the opening lever  31  is connected with an outside link. The outside link is connected to an outside handle (not shown) which is disposed on the outside of the door. The opening lever  31  is rotated in a counter-clockwise direction as indicated in FIG. 4 against the force of the torsion spring  31   b  by the operation of the outside handle in a door opening direction (the operation for opening the door using the outside handle). A lifting lever  32  is disposed on a periphery of a shaft  42   b  for unitary rotation therewith. The shaft  42   b  is extended through the second cover  13  via a bush  33 . An engaging portion  32   a , formed on periphery of the lifting lever  32 , is extended above the upper end of the engaging portion  23   c  of the open link  23 .  
         [0037]    The latch mechanism  40  includes a latch  41 , a pawl  42 , a pair of torsion springs  43  and  44  applying spring forces to the latch  41  and the pawl  42 , respectively. The latch  41  is rotatably supported between the second cover  13  and the base plate  16  by a supporting pin  41   a . The supporting pin  41   a , extending through the sub base plate  15 , the second cover  13  and the base plate  16 , is supported by both the second cover  13  and the base plate  16 . One end of the torsion spring  43 , which is provided on the supporting pin  41   a , is engaged with the latch  41 . The other end of the torsion spring  43  is engaged on the second cover  13 . The torsion spring  43  applies the predetermined spring force to the latch  41  for regulating the rotation of the latch  41  so that the latch  41  can be returned to its initial position by the spring force when the latch  41  is rotated to be out of an initial position thereof. The latch  41  is held by the torsion spring  43  so that an opening of a latch groove  41   b  can substantially coincide with an opening of an insertion groove  16   a  formed in the base plate  16 . The pawl  42  includes a block-like main pawl body  42   a  and a shaft  42   b  extending approximately perpendicular to the main pawl body  42   a . The shaft  42   b  extends into the second casing portion  11   b  through the second cover  13  and the sub base plate  15  via the bush  33 . The shaft  42   b  is rotatably supported by the sub base plate  15  via the bush  33 . The shaft  42   b  is further rotatably supported by the base plate  16  via the bush  34 . The torsion spring  44  is provided on the shaft  42   b  at the middle portion between the main pawl body  42   a  and sub base plate  15 . The lifting lever  32  is rigidly connected to one end of the shaft  42   b  for unitary rotation therewith (after the torsion spring  44  is provided on the shaft  42   b , the end of shaft  42   b  is disposed into the lifting lever  32  and formed with a head by riveting as shown in FIG. 5). One end of the torsion spring  44  is engaged with the pawl  42 . The other end of the torsion spring  44  is engaged with the sub base plate  15 . The torsion spring  44  applies a predetermined spring force to the shaft  42   b  for regulating the rotation of the shaft  42   b  so that the pawl  42  can be returned to its initial position by the spring force when the pawl  42  is rotated. The pawl  42  causes the main p awl body  42   a  to contact the periphery of the latch  41 .  
         [0038]    When a striker  45 , which is mounted on a body of the vehicle, moves relatively into the latch  41  through the insertion groove  16   a , the latch  41  is rotated by the pressure from the striker  45  against the spring force of the torsion spring  43 . The latch  41  then receives the striker  45 . While the latch  41  receives the striker  45 , the pawl  42  slidably contacts on the outer periphery of the latch  41 . The pawl  42  moves into a latch portion  41   c  to be engaged thereon. The pawl  42  holds the latch  41  which has been rotated to receive the striker  45 . Thus, the pawl  42  keeps the latch  41  engaged with the striker  45 . Under the above state, the door of the vehicle is closed. Under the above engagement state, the latch  41  is returned to an initial position thereof by the force of the torsion spring  43 . When the pawl  42  is rotated to be moved away from the latch portion  41   c  by the rotation of the lifting lever  32 , while the latch  41  is returned by the spring force of the torsion spring  43 , the opening of the latch groove  41   b  is rotated to match the opening direction of the insertion groove  16   a . Under the above state, the striker  45  can be moved away from the latch groove  41   b  and the opening of the insertion groove  16   a  of the base plate  16 . The door of the vehicle can then be opened.  
         [0039]    The pawl  42  functions for selectively holding between the engaging condition in which the latch  41  engages with the striker  45  and the disengaging condition in which the latch  41  disengages from the striker  45 . When the pawl  42  is rotated against the spring force of the torsion spring  44 , the pawl  42  is moved away from the latch portion  41   c  of the latch  41 . The pawl  42  then changes to the disengaging condition between the latch  41  and the striker  45  from the engaging condition between the latch  41  and the striker  45 .  
         [0040]    The operation modes of the door lock system consists of the operation modes causing the door lock system be in the unlocked state capable of releasing the engagement between the latch  41  and the striker  45 , the operation modes causing the door lock system be in the locked state incapable of releasing the engagement between the latch  41  and the striker  45 , and the operation modes causing the door to open or to close when the door lock system is in the unlocked state. The eight operation modes will be described as follows.  
         [0041]    First operation mode: The door is opened by operating the inside handle disposed on the inside of the vehicle when the door lock system is in the unlocked state as viewed in FIG. 7. In the door lock system, when the inside handle is operated to open the door, the second inside lever  51  is rotated in a clockwise direction (as indicated in FIG. 1) via the inside cable  52 . The first inside lever  21  is rotated by the second inside lever  51  in a clockwise direction (as indicated in FIG. 7). When the first inside lever  21  is rotated in the clockwise direction (as indicated in FIG. 7), the end of the inside lever  21  engages with the lower surface of the engaging portion  23   c  of the open link  23  and pushes up the open link  23 . The open link  23  causes the upper periphery of the engaging portion  23   c  to engage with the engaging portion  32   a  of the lifting lever  32 . The lifting lever  32  is then rotated by the open link  23 . The pawl  42  is rotated by the lifting lever  32  to be moved away from the latch portion  41   c  of the latch  41 . Namely, a regulation of the rotation of the latch  41  by the engagement with the main pawl body  42   a  is released. Thus, the latch  41  is returned to its initial position by the spring force of the torsion spring  43 . When the latch  41  is separated from the striker  45  by a force of the door opening, the latch  41  releases the striker  45 . Then, the latch  41  is separated from the striker  45 . Thus the engagement between the latch  41  and the striker  45  is released by operating the inside handle to open the door. The door can then be opened.  
         [0042]    Second operation mode: The door is opened by operating the outside handle disposed on the outside of the vehicle when the door lock system is in the unlocked state as viewed in FIG. 7. In the door lock system, when the outside handle is operated to open the door, the opening lever  31  is rotated against the torsion spring  31   b . The open link  23  is then pushed up by the opening lever  31 . The open link  23  causes the upper periphery of the engaging portion  23   c  to engage with the engaging portion  32   a . The lifting lever  32  is then rotated by the open link  23 . The lifting lever  32  rotates the pawl  42  to be separated from the latch portion  41   c  of the latch  41 . Namely, a regulation of the rotation of the latch  41  by the engagement with the main pawl body  42   a  is released. Thus, the latch  41  is returned to its initial position by the spring force of the torsion spring  43 . When the latch  41  is separated from the striker  45  by a force of the door opening, the latch  41  releases the striker  45 . Then, the latch  41  is separated from the striker  45 . Thus the engagement between the latch  41  and the striker  45  is released by operating the outside handle to open the door. The door can then be opened.  
         [0043]    In the first and second operation modes, when the open link  23  is pushed up by the opening lever  31  or the first inside lever  21 , the canceling lever  22  is rotated in the counterclockwise direction as shown in FIG. 7 by the engagement between the first engaging groove  23   a  of the open link  23  and engaging pin  22   b  of the canceling lever  22 .  
         [0044]    Third operation mode: The door lock system, by operating the locking knob inside the vehicle, is brought into the locked state such that the engagement between latch  41  and the striker  45  is impossible. When the door lock system is in the unlocked state as viewed in FIG. 7, the locking cable  53  is moved by operating the locking knob. The locking lever  24  is rotated, and then the active lever  27  is rotated in the counterclockwise direction as shown in FIG. 7. Thus the active lever  27  causes the open link  23  to rotate about the connecting portion between the open link  23  and the opening lever  31  by the engagement between the second engaging groove  23   b  and the engaging pin  27   b . The open link  23  is thereby shifted from the unlocking position shown in FIG. 7 to the locking position shown in FIG. 8. The unlocking position is the position for the open link  23  which causes the door lock system to be in the unlocked state. The lock position is the position for the open link  23  which causes the door lock system to be in the locked state. Even if the open link  23  is moved as viewed in FIG. 10 by operating the inside handle or the outside handle, the open link  23  fails to engage with the lifting lever  32 , whereby the lift lever  32  and the pawl  42  are not rotated. Thus, even if the inside handle or the outside handle are operated for opening the door, the unlocked state for releasing the engagement between the latch  41  and the striker  45  is not established. Thus, the locked state remains, and the door can not be opened. When the open link  23  is moved from the unlocking position shown in FIG. 7 to the locking position shown in FIG. 8, the canceling lever  22  is rotated in the counterclockwise direction shown in FIG. 8 by the engagement between the first engaging groove  23   a  of the open link  23  and the engaging pin  22   b.    
         [0045]    Fourth operation mode: The door lock system is brought into either the locked state or the unlocked state by a key operated rotation of the key cylinder from outside of the vehicle. In the door lock system, when the key cylinder is rotated by the key, the key lever  28  is rotated. The active lever  27  is then selectively rotated by the key lever  28  via the idle lever  29  to be in either the position shown in FIG. 7 or the position shown in FIG. 8. The open link  23  is selectively moved by the active lever  27  to be in the unlocking position shown in FIG. 7 or the locking position shown in FIG. 8 via the engagement between the second engaging groove  23   b  and the engaging pin  27   b . The rotation of the key cylinder, by manipulating the key, causes the door lock system to be selectively in either a) the unlocked state which is capable of releasing the engagement between the latch  41  and the striker  45  or b) the locked state which is incapable of releasing the engagement.  
         [0046]    Fifth operation mode: The door lock system is brought into either the locked state or the unlocked state when the electric motor  25  is remotely-controlled by operating a remote device control, such as a lock-unlock switch which acts as a key, from outside of the vehicle. In the door lock system, when the lock/unlock switch is operated, the electric motor  25  rotates the wheel gear  26  through a predetermined rotation amount via the worm gear  25   a . When the wheel gear  26  rotates one or the other direction, either of the engaging pins  26   a  or  26   b  selectively engages a part of engaging concave portion  27   c  of the active lever  27 . The active lever  27  is then rotated to the position shown in FIG. 7 or the position shown in FIG. 8. Therefore, the open link  23  is selectively moved to the unlocking position shown in FIG. 7 or the locking position shown in FIG. 8 via the engagement between the second engaging groove  23   b  and the engaging pin  27   b . Thus the operation of the lock/unlock switch causes the door lock system to be selectively in either a) the unlocked state which is capable of releasing the engagement between the latch  41  and the striker  45  by the opening operation of the outside handle or b) the locked state which is incapable releasing the engagement.  
         [0047]    Sixth operation mode (canceling operation): The door is closed without operating a door handle such as the outside handle or the inside handle after bringing the door lock system into the locked state by a manual operation of the locking knob while the door is open. In the door lock system, as the door is closed, the striker  45  causes the latch  41  to rotate. Accordingly, the pawl  42  rotates by the rotation of the latch  41 . Then the lifting lever  32  rotates from the position shown by two-dot-lines in FIG. 11 to the position shown by solid lines in FIG. 11, thereby rotating the canceling lever  22  from the position shown by the two-dot-lines in FIG. 11 to the position shown by the solid lines in FIG. 11. Thus the open link  23  at the locking position shown by the two-dot-lines is moved to the unlocking position shown by the solid lines due to engagement between the first engaging groove  23   a  and the engaging pin  22   b . In the above process, the door lock system is in the unlocked state capable of releasing the engagement between the latch  41  and the striker  45 . The door can then be opened by opening the door using either the outside handle or the inside handle.  
         [0048]    Seventh operation mode (keyless locking operation): The door lock system is brought into the locked state in such a manner that while the door is opened, the locking knob is manually operated to bring the door lock system into the locked state and thereafter the door is closed. In the door lock system, when the outside handle is operated for opening the door while the door lock system is in the locked state, the opening lever  31  is rotated to push the open link  23  up as shown in FIG. 12. Thus, the engaging pin  22   b  of the canceling lever  22  is located at a downside of the first engaging groove  23   a  and is out of engagement with anything. When the door is closed in the above condition, the latch  41  is rotated by the striker  45 . Then, the pawl  42  causes the lifting lever  32  to rotate, whereby the canceling lever  22  is rotated in the clockwise direction shown in FIG. 12. However, the engaging pin  22   b  of the canceling lever  22  is located in the first engaging groove  23   a  of the open link  23  and is out of engagement with anything, thereby not moving the open link  23  to the unlocking position. The open link  23  is therefore kept in the locking position. Thus, the door lock system can be in the locked state which is capable of releasing the engagement between the latch  41  and the striker  45  when the door is closed. In addition, if the door opening operation by the outside handle is interrupted after closing the door, the condition as shown in FIG. 12 is changed to the condition as shown in FIG. 8, whereby the door lock system remains in the locked state.  
         [0049]    Eighth operation mode (one motion operation): In succession, the locked state of the door lock system is cancelled and the door is opened by opening the door using the inside handle when the door lock system is in the locked state which is capable releasing the engagement between the latch  41  and the striker  45 . In the door lock system, when the inside handle is operated for opening the door, the second inside lever  51  and the first inside lever  21  are rotated as one unit. Then, the engaging projection  21   c  of the first inside lever  21  rotates the canceling lever  22 , which causes the open link  23  to move from the locking position shown by the two-dot-lines in FIG. 13 to the unlocking position shown by the solid lines in FIG. 11 by the engagement between the first engaging groove  23   a  and the engaging pin  22   b . The active lever  27  and the idling lever  29  are then moved from the locking position shown by the two-dot lines in FIG. 13 to the unlocking position indicated by the solid lines in FIG. 11 by the engagement between the second engaging groove  23   b  and the engaging pin  27   b . The open link  23  is thus pushed up by the first inside lever  21 , thereby causing the lifting lever  32  and the pawl  42  to rotate. Thereafter the door can be opened.  
         [0050]    All members of the first link mechanism  20  and the second link mechanism  30  of the door lock system are accommodated within the housing  10 . No members of these link mechanisms  20 ,  30  can be placed outside the housing  10 . Thus each member of both the first link mechanism  20  and the second link mechanism  30  can not be operated from outside of the door through the gap between the door and the body of the vehicle. Therefore, the door lock system can keep the engagement between the latch  41  and the striker  45  thereby preventing the door from opening. In addition, since each member of both the first link mechanism  20  and the second link mechanism  30  is not exposed outside the housing  10 , each of the members absolutely can not be exposed to water which enters the door.  
         [0051]    In the door lock system, the housing  10  works as a protector accommodating structural members of the link mechanisms  20 ,  30 . Thus, an added protector is not necessary as an additional member of the housing  10 . Accordingly, increase in manufacturing cost, labor for assembling and the number of members can be avoided.  
         [0052]    In the door lock system, all structural members of the first link mechanism  20  are accommodated within one of the first casing portion  11   a  of the main housing portion  11  and the first cover  12 , and all structural members of the second actuating mechanism  30  are supported by the sub base plate  15  which is disposed between the second casing portion  11   b  of the main housing portion  11  and the second cover  13 . Thus, the sub base plate  15  further supports the latch mechanism  40  together with the base plate  16 . The door lock system is therefore significantly miniaturized in comparison to a conventional sub base plates. Thus, the entire door lock system is downsized.  
         [0053]    The principles of the preferred embodiment described herein is therefore illustrative and not restrictive, the scope of the invention being indicated in the appended claims and all variations which come within the spirit and meaning of the claims are intended be embraced therein.