Abstract:
A key interlock device includes a solenoid that holds a plunger when the solenoid is excited, and a link member that includes a shaft around which the link member is rotatable, and engages with the plunger so as to transmit a restraining force opposing an operation force of a key when the solenoid is excited. The shaft of the link member is disposed on a virtual line extending from a line of force of the operation force of the key. The key interlock device may include an engaging part through which the key interlock device is attached to a body of a steering lock device and which is disposed behind the shaft to which the operation force of the key applies.

Description:
[0001]    The present application is based on Japanese patent application No. 2010-131109 filed on Jun. 8, 2010, the entire contents of which are incorporated herein by reference. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    This invention relates to a key interlock device that is attached to a steering lock device for a vehicle. 
         [0004]    2. Description of the Related Art 
         [0005]    Steering lock devices have been popularized that are equipped with a key interlock device to restrain a steering key (i.e., ignition key) from being turned form an “ACC” position to “LOCK” position when the vehicle is driven. The key interlock device uses an attraction type solenoid that is operable to attract a plunger when it is excited (e.g., JP-A-2000-229557). 
         [0006]    The attraction type solenoid operates to attract the plunger when a drive current is fed (i.e., the solenoid is excited or energized), so that a problem arises that the power consumption increases. Therefore, in recent years, the key interlock device is desired to use a retention type solenoid that can relatively save the power consumption. 
       SUMMARY OF THE INVENTION 
       [0007]    Although the retention type solenoid can hold the plunger at the excited state, it cannot have the plunger actively operate. Thus, when the retention type solenoid is used for the key interlock device, a lock mechanism needs to be constructed adding a new reinforcement member such as a link. Therefore, it is necessary to prevent an increase in the manufacturing cost due to increased parts, complicated installation process and the like. 
         [0008]    Accordingly, it is an object of the invention to provide a key interlock device that can prevent an increase in the manufacturing cost when the retention type solenoid is used. 
         [0000]    (1) According to one embodiment of the invention, a key interlock device comprises: 
         [0009]    a solenoid that holds a plunger when the solenoid is excited; and 
         [0010]    a link member that comprises a shaft around which the link member is rotatable, and engages with the plunger so as to transmit a restraining force opposing an operation force of a key when the solenoid is excited, 
         [0011]    wherein the shaft of the link member is disposed on a virtual line extending from a line of force of the operation force of the key. 
         [0012]    In the above embodiment (1) of the invention, the following modifications and changes can be made. 
         [0013]    (i) The link member further comprises a linear arm part along the line of force of the operation force of the key. 
         [0014]    (ii) The link member further comprises a resin. 
         [0000]    (2) According to another embodiment of the invention, a key interlock device comprises: 
         [0015]    a solenoid that holds a plunger when the solenoid is excited; and 
         [0016]    a link member that comprises a shaft around which the link member is rotatable and engages with the plunger so as to transmit a restraining force opposing an operation force of a key when the solenoid is excited, 
         [0017]    wherein the shaft of the link member is disposed on a virtual line extending from a line of force of the operation force of the key, and 
         [0018]    wherein the key interlock device further comprises an engaging part through which the key interlock device is attached to a body of a steering lock device and which is disposed behind the shaft to which the operation force of the key applies. 
         [0019]    In the above embodiment (2) of the invention, the following modifications and changes can be made. 
         [0020]    (iii) The link member further comprises a linear arm part along the line of force of the operation force of the key. 
         [0021]    (iv) The link member further comprises a resin. 
         [0022]    (v) The engaging part is disposed at one end of the key interlock device and is adapted to be inserted into an opening of the body of the steering lock device, and the key interlock device is fixed to the body at an other end thereof. 
         [0023]    (vi) The engaging part is disposed at one end of the key interlock device in a direction of turning back the key from an ACC position to a LOCK position thereof. 
         [0024]    (vii) The arm part comprises a pressure receiving surface at an end, and the pressure receiving surface contacts an action surface to which the operation force of the key applies. 
         [0025]    (viii) The pressure receiving surface contacts the action surface to restrain the key from being turned back from an ACC position to a LOCK position thereof when the solenoid is excited. 
       Points of the Invention 
       [0026]    According to one embodiment of the invention, a key interlock device (or interlock unit) is constructed such that a rotation shaft part for rotatably supporting a link and a pin penetrating through the rotation shaft part are disposed on a virtual line extending from a line of force of a rotation force generated in the tangential direction of a cam shaft operated by a key (regular or authentic key). Since the rotation force from the cam shaft is received at the rotation shaft part and the pin, the burden of a load to the link can be reduced. In addition, an arm part of the link is formed to extend linearly from the rotation shaft part as a center, so that only a compression load component acts on the arm part without a bending stress component. The link mechanism thus constructed is used as a reinforcement part of a retention solenoid, so that the link may be formed of a resin such as PBT having high resistance to a compression load instead of metals. Thus, the manufacturing cost of the key interlock device can be reduced. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0027]    The preferred embodiments according to the invention will be explained below referring to the drawings, wherein: 
           [0028]      FIG. 1A  is a side view schematically showing a steering lock device using a key interlock device according to one embodiment of the present invention, in which a part of a bracket for fixing a steering column thereof is shown in a partially broken state; 
           [0029]      FIG. 1B  is a bottom view schematically showing the steering lock device shown in  FIG. 1A ; 
           [0030]      FIG. 2  is a longitudinal cross-sectional view schematically showing an inner structure of the steering lock device using the key interlock device according to one embodiment of the present invention; 
           [0031]      FIG. 3  is a cross-sectional view schematically showing parts of a lock bar and the steering column in the steering lock device using the key interlock device according to one embodiment of the present invention; 
           [0032]      FIG. 4  is an exploded perspective view schematically showing an internal constitution of an interlock unit as the key interlock device according to one embodiment of the present invention; 
           [0033]      FIG. 5  is a perspective view schematically showing an installation method of an interlock unit as the key interlock device according to one embodiment of the present invention in the steering lock device; 
           [0034]      FIG. 6A  is a front view schematically showing an inner structure of the interlock unit as the key interlock device according to one embodiment of the present invention, in which the interlock unit is in an interlock state; and 
           [0035]      FIG. 6B  is a front view schematically showing an inner structure of the interlock unit as the key interlock device according to one embodiment of the present invention, in which the interlock unit is in a state that the interlock state is released. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0036]    A preferred embodiment of the present invention will be detailed below with reference to drawings. First, a steering lock device  1  will be explained, that includes an interlock unit  30  as an interlock key device according to the present invention. Here,  FIG. 1A  is a side view schematically showing the steering lock device  1  using the interlock key device according to one embodiment of the present invention, in which a part of a bracket  102  for fixing a steering column  80  thereof is shown in a partially broken state. In addition,  FIG. 1B  is a bottom view schematically showing the steering lock device  1  shown in  FIG. 1A . The steering lock device  1  is configured so as to include a key part  10 , a steering lock part  20 , the interlock unit  30  and an ignition switch unit  40 . 
         [0037]      FIG. 2  is a longitudinal cross-sectional view schematically showing an inner structure of the steering lock device  1 . A case  101  of the steering lock device  1  is integrally formed of a metal such as zinc die-cast. A key cylinder  110  that has a cylinder  111  and a rotor rotatably housed in the cylinder  111  is mounted in the case  10  by insertion thereinto. A key hole  112   a  into which a key K is inserted is formed in the rotor  112  of the key cylinder  110  so as to extend toward the inside in the axis direction. 
         [0038]    In addition, a plurality of tumblers  113 ,  113 , . . . having an elongate shape in the diameter direction (vertical direction) of the rotor  112  are housed in the rotor  112  along the longitudinal direction thereof in a movable state. Each end portion of tumblers  113 ,  113 , . . . projects from an outer periphery of the rotor  112  so as to engages with an inner periphery of the cylinder  111  in a state that the key K is not inserted therein, thereby the rotor  112  is restrained from being rotated. On the other hand, when a proper key K is inserted into the rotor  112 , each tumbler  113 ,  113 , . . . corresponding to an end surface of a mountain-groove shape of the key K engages with the end surface of the key K so that all of the tumblers  113 ,  113 , . . . evacuate from the outer periphery of the rotor  112 . Thereby, it becomes possible to carry out rotation operation of the rotor  112 . 
         [0039]    A slide piece  114  is mounted in the front lower side of the rotor  112  in the diameter direction in a movable state. The outer surface of the slide piece  114  is curved at the same curvature as that of the outer surface of the rotor  112 , so that the rotor  112  and the slide piece  114  are configured to be integrally rotated in the key cylinder  110 . In addition, in a state that the key K is inserted into the rotor  112 , the slide piece  114  is restrained from moving in the center direction of the rotor  112  by that the end portion thereof is brought into contact with a part of the key K. 
         [0040]    An antilock lever  115  that is an elongated movable member is mounted in the lower part of the key cylinder  110 , parallel to the center axis of the key cylinder  110  and rotatably around a shaft of the central part thereof. A front end part  115   a  is formed in the front end of the antilock lever  115  so as to be bent toward the slide piece  114  located at the upper position, and a back end part  115   b  that is capable of engaging with an engaging projection  203   b  of a slider  203  described below is formed in the back end thereof. Further, elastic force acts on the antilock lever  115  in a direction (elevating direction) from the front end part  115   a  to the slide piece  114  by a spring or the like (not shown). In a state that the rotor  112  is located at the “LOCK” position or the key K is removed from the key cylinder  110 , the elastic force acts on the antilock lever  115 , thereby the front end part  115   a  elevates and simultaneously the back end part  115   b  descends so that the antilock state is released (steering lock allowing state). 
         [0041]    A cam shaft  116  is formed so as to be combined with a rear shaft of the rotor  112 . The cam shaft  116  includes an outer tubular part  116   a  having an approximately cylindrical shape and an inner tubular part  116   b  having an approximately cylindrical shape similarly so that both are integrally formed at the front part in combination with each other. The rear shaft  112   b  of the rotor  112  is fitted to an inner periphery of the inner tubular part  116   b  of the cam shaft  116 , and simultaneously a rear end part of the inner tubular part  116   b  projects from the case  101  so as to be combined with the ignition switch unit  40 . Thereby, the rotor  112  of the key cylinder  110  is operated to be rotated by the proper key K, so that the ignition switch unit  40  is operated via the cam shaft  116 . 
         [0042]    A torsion spring  117  is housed in a space between the outer tubular part  116   a  and the inner tubular part  116   b  of the cam shaft  116 . One end of the torsion spring  117  engages with the outer tubular part  116   a  of the cam shaft  116 , thus when the rotor  112  of the key cylinder  110  reaches an “ON” position by rotation operation of the key K, another end of the torsion spring  117  engages with the case  101 , thereby a spring force acts on the cam shaft  116  in the direction in which operation of the key K is returned from a “START” position to the “ON” position. 
         [0043]    A cam surface  116   c  is formed in a lower part of the outer tubular part  116   a  of the cam shaft  116 , that slides in contact with a follower part  203   a  of a slider  203  described below. 
         [0044]    The steering lock part  20  includes a lock bar  201 , a compression spring  202  and the slider  203 . The lock bar  201  is formed of high stiffness metal so as to have a rod-like shape, and the distal end part thereof is mounted in a lower part of the steering lock device  1  so as to be movable back and forth from the case  101  to a side of the steering column  80 . In addition, a spring force always acts on the lock bar  201  in the direction in which it exits from the case  101  by the compression spring  202  housed in the case  101 . 
         [0045]    In the case  101 , a groove part  201   b  is formed in an upper part of the lock bar  201 , a lower part of the slider  203  is fitted to the groove part  201   b . Together with this, a rear surface of upper part of the slider  203  is brought into contact with an inner wall  101   c  of rear part of the case  101 , thereby the lock bar  201  is prevented from falling out of the case  101 . 
         [0046]    The follower part  203   a  is integrally formed in an upper part of the slider  203  so as to follow in contact with the cam surface  116   c  of the above-mentioned cam shaft  116 . In addition, an engaging projection  203   b  capable of engaging with the rear end part  115   b  of the above-mentioned antilock lever  115  is formed in an upper part of the front portion of the slider  203 . 
         [0047]    Here,  FIG. 3  is a cross-sectional view schematically showing parts of the lock bar  201  and the steering column  80  in the steering lock device  1  shown in  FIG. 1 . A bracket  102  is formed so as to have a semicircular arc shape and one end is openable supported via a hinge shaft  102   a  in a hinge block part  101   b  of the case  101 . The bracket  102  is opened, the steering column  80  is fixed to the case  101  and another end is fixed to a boss block part  101   a  via a bolt  103  in a state that the bracket  102  is closed, thereby the steering column  80  is mounted in the steering lock device  1 . 
         [0048]    As shown in  FIG. 3 , in a lock position in which the lock bar  201  advances toward a side of the steering column  80 , the distal end part  201   a  of the lock bar  201  enters into a concave portion  82   a  of a spline boss  82  fitted to the steering shaft  81  so as to engage therewith, thereby, the steering shaft  81  is restrained from being rotated. In addition, in an unlock position in which the lock bar  201  evacuates, the distal end part  201   a  of the lock bar  201  and spline boss  82  does not engage with each other, the rotation restraint of the steering shaft  81  is released. 
         [0049]    According to the above-mentioned configuration of the steering lock part  20 , in a state that the key K is removed from the key hole  112   a , the slide piece  114  is not restrained from moving, thereby slide piece  114  is elevated by the front end part  115   a  of the antilock lever  115 , and simultaneously the back end part  115   b  of the antilock lever  115  descends. Consequently, the engaging projection  203   b  of the slider  203  and the back end part  115   b  of the antilock lever  115  can not engage with each other, thus the lock bar  201  advances toward the lock position by the elastic expansion force of the compression spring  202  and simultaneously the rear surface of upper part of the slider  203  fitting to the groove part  201   b  of the lock bar  201  is brought into contact with the inner wall of rear part of the case  101 , thereby the lock bar  201  is maintained in the lock position. 
         [0050]    In the course that the proper key K is inserted into the key hole  112   a , and the rotor  112  is rotated from the “LOCK” position to the “ACC” position, the outer surface of the slide piece  114  moves to the position corresponding to the outer periphery of the rotor  112 , thereby the front end part  115   a  of the antilock lever  115  is pushed downward, and simultaneously the rear end part  115   b  of the antilock lever  115  is elevated. At this time, the cam shaft  116  is rotated in conjunction with rotation of the rotor  112 , thereby the slider  203  and the engaging projection  203   b  in the front part of the slider  203  move forward together with the follower part  203   a  that follows in contact with the cam surface  116   c  of the cam shaft  116 , and further the lock bar  201  that fits to the slider  203  in the groove part  201   b  evacuates to the unlock position. In addition, when the rotor  112  operated to be rotated reaches the “ACC” position, the engaging projection  203   b  engages with the rear end part  115   b  of the antilock lever  115 , thereby the slider  203  is held at the position, and simultaneously the lock bar  201  fitting to the slider  203  is held at the unlock position. Thereby, after the key K is operated to be rotated to the “ACC” position, the steering lock is made antilock so as to prevent the steering lock from malfunctioning. 
         [0051]    Next, the interlock unit  30  as a key interlock device according to an embodiment of the present invention will be explained. 
         [0052]      FIG. 4  is an exploded perspective view schematically showing an internal constitution of the interlock unit  30  as the key interlock device according to an embodiment of the present invention. As shown  FIG. 4 , the interlock unit  30  includes a case member  31  and a cover member  32 , and a holding solenoid  33 , a link  34 , a release link  35  and a torsion spring  37  that are housed in the case member  31  and the cover member  32 . 
         [0053]    The case member  31  is integrally formed of a resin material having good heat conductivity such as PBT containing glass fibers by an injection molding. The case member  31  has an outer shape of an approximate rectangle, and is formed so as to have a frame-like shape of which front and rear parts are mostly opened. When viewed in the insertion direction of the key K, at a bottom right part of the case member  31 , a screw bracket part  31   a  having a hole  311  is formed to project, and at a bottom left part opposite to the screw bracket part  31   a , an engaging projection part  31   b  is formed. 
         [0054]    In addition, the inner part of the case member  31  in which the engaging projection part  31   b  is formed is partially opened downward, and simultaneously a bearing part  31   c  having a cylindrical shape is formed in the side wall part of the case member  31 . In addition, in two sites of rear end part of the case member  31 , fitting projection parts  31   e ,  31   d  having a pin-like shape are formed so as to project, and in a predetermined site of the outer wall part of the case member  31 , a plurality of engaging claws  31   f  are formed. 
         [0055]    The cover member  32  is formed of the same resin material as the case member  31  by an injection molding so as to have an approximately plate-like shape. The cover member  32  is a member mounted for blocking the open part in the rear side of the case member  31 , in which fitting hole parts  32   d ,  32   e  that fit to the fitting projection parts  31   e ,  31   d  of the case member  31  are formed, and a plurality of engaging frame parts  32   f  that engage with the engaging claws  31   f  of the case member  31  are formed so as to project. In addition, in the lower part of the cover member  32  corresponding to the bearing part  31   c  of the case member  31 , a pin pole  32   c  is formed so as to be opened. In addition, above the pin pole  32   c  of the cover member  32 , an open part  32   g  is formed by that a step part is opened, and simultaneously in the opening end of the open part  32   g , a spring engaging part  32   h  is formed so as to project. 
         [0056]    The holding solenoid  33  includes a plunger  331  and an engaging shaft  332  perpendicular to the plunger  331 . In addition, a harness connector  333  is mounted in the front part of the holding solenoid  33 . The holding solenoid  33  becomes in an excited state by that the driving current is supplied, so that the holding solenoid  33  generates holding force (attraction force) restraining the plunger  331  from projecting. 
         [0057]    The holding solenoid  33  is housed in the case member  31  so as to expose the harness connector  333  from the open part of front side of the case member  31  to the outside. 
         [0058]    The link  34  is a reinforcement member integrally formed of a synthetic resin material such as PBT containing glass fibers similarly to the case member  31 . The link  34  includes an arm part  34   c  of a linear shape having a pressure receiving surface  34   a  being flat-shaped in the right side when viewed from the insertion direction of the key K, a rotation shaft part  34   b  formed in the left basic end side of the arm part  34   c , engaging groove parts  34   d ,  34   d  having a two-pronged portion bent at an approximately right angle at the position of the rotation shaft part  34   b , and a spring engaging part  34   e  formed in the left front part of one of the engaging groove parts  34   d  so as to project. 
         [0059]    The release link  35  is a member formed of a resin material having good sliding characteristics such as POM, and has a taper surface  35   a  having a downward-facing slope formed in the right side when viewed from the insertion direction of the key K. In addition, a bearing hole  35   b  into which the rotation shaft part  34   b  of the link  34  is inserted is formed in the end part opposite to the taper surface  35   a  so as to be opened. The release link  35  is supported by the rotation shaft part  34   b  of the link  34  at the bearing hole  35   b , thereby it is rotatably mounted relatively to the link  34 . 
         [0060]    As shown in  FIG. 4 , the torsion spring  37  is formed so as to have such a configuration that two spiral parts having the same diameter and axis are combined with each other at a combining part  37   c . The torsion spring  37  comes into contact with the release link  35  at the combining part  37   c , and the two spiral parts are respectively fitted to both end parts of the rotation shaft part  34   b  of the link  34  so as to stride the link  34  and the release link  35 . In addition, simultaneously one end  37   a  of the torsion spring  37  engages with the spring engaging part  34   e  of the link  34 . Thereby, the link  34  and the release link  35  are prevented from being removed in the axis direction by being sandwiched between the two spiral parts of the torsion spring  37  and simultaneously elastic force acts in a direction of closing each other. 
         [0061]    The link  34  and the release link  35  are rotatably mounted in the case member  31  by that one end part of the rotation shaft part  34   b  of the link  34  is fitted to the bearing part  31   c  of the case member  31 , and groove parts of the two-pronged portion of the engaging groove parts  34   d ,  34   d  are engaged with the engaging shaft  332  of the holding solenoid  33 . At this time, the arm part  34   c  of the link  34  and the taper surface  35   a  of the release link  35  are mounted so as to expose downward from the open part in the lower side of the case member  31 . 
         [0062]    Then, another end part of the rotation shaft part  34   b  of the link  34  is inserted into an bearing part (not shown) formed in the inner wall part of the pin hole  32   c  of the cover member  32 , and a pin  36  formed of a metal is inserted into the pin hole  32   c  so as to pass through the rotation shaft part  34   b  of the link  34 . At the same time, the fitting projection parts  31   e ,  31   d  of the case member  31  were fitted to the fitting hole parts  32   d ,  32   e  of the cover member  32 , and the engaging frame parts  32   f  of the cover member  32  is engaged with the engaging claws  31   f  of the case member  31 , thereby the cover member  32  is mounted in the case member  31 . 
         [0063]    In this state, another end  37   b  of the torsion spring  37  remains projecting from the open part  32   g  of the cover member  32  to the outside. The another end  37   b  of the torsion spring  37  projecting to the outside is engaged with the spring engaging part  32   h  while twisted in the direction in which the spiral parts are closed, thereby elastic force of the torsion spring  37  acts on the link  34  and the release link  35  in the direction in which the spiral parts are opened via the combining part  37   c . As a result, while the link  34  and the release link  35  are restrained by the holding solenoid  33  via the engaging groove parts  34   d ,  34   d , parts of the arm part  34   c  exposed from the case member  31  and the taper surface  35   a  of the release link  35  provide elastic force downward. 
         [0064]      FIG. 5  is a perspective view schematically showing an installation method of the interlock unit  30  as the key interlock device according to one embodiment of the present invention in the steering lock device  1 . As shown in  FIG. 5 , in the steering lock device  1 , a housing frame part  101   d  that houses the interlock unit  30  therein and a screw boss part  101   f  are integrally formed with the case  101  at the installing position of the interlock unit  30  in the backward upper part of the key part  10 . In addition, an engaging hole  101   e  is formed in the left side wall of the housing frame part  101   d  so as to be opened. 
         [0065]    The interlock unit  30  is mounted in the housing frame part  101   d  of the steering lock device  1  by that the engaging projection part  31   b  in the left side is inserted into the engaging hole  101   e  of the housing frame part  101   d  from the inside so as to be engaged with each other, and then a mounting screw  38  is inserted into the hole  311  of the screw bracket part  31   a  so as to be fastened to a screw hole of the screw boss part  101   f.    
         [0066]      FIG. 6A  is a front view schematically showing an inner structure of the interlock unit  30  as the key interlock device according to one embodiment of the present invention when viewed from the insertion direction of the key K, in which the interlock unit  30  is in an interlock state. Similarly,  FIG. 6B  is a front view schematically showing an inner structure of the interlock unit  30  as the key interlock device according to one embodiment of the present invention, in which the interlock unit  30  is in a state that the interlock state is released. 
         [0067]    In case that a shift lever of a vehicle is operated to a shift position other than “P (parking)”, driving current is supplied to the holding solenoid  33  from a control device (not shown). At this time, the holding solenoid  33  becomes in an excited state, thereby the position of the plunger  331  is held, and simultaneously the link  34  is restrained from being rotated via the engaging groove parts  34   d  engaging with the engaging shaft  332  (the interlock state). 
         [0068]    As shown in  FIG. 6A , the link  34  transmits a rotation restraining force generated by the holding solenoid  33  in an excited state to the cam shaft  116 . In order to oppose against the rotation restraining force, the rotation shaft part  34   b  and the pin  36  of the link  34  are arranged on an extension of a line of force of the rotation operation force of the key K generated in the tangential direction of the cam shaft  116 . 
         [0069]    Namely, in case that the key K is operated so as to be returned from the “ACC” position to the “LOCK” position in the interlock state, the link  34  is restrained from being rotated by the holding solenoid  33 , so that a state that an action surface  116   d  of the cam shaft  116  and the pressure receiving surface  34   a  of the arm part  34   c  of the link  34  are brought into contact with each other is maintained. Thereby, the rotation operation force by the key K is received at the rotation shaft part  34   b  and the pin  36  passing through the rotation shaft part  34   b  located on an extension of a line of force thereof, and simultaneously a rotation restraining force as the counteraction is transmitted to the cam shaft  116  via the link  34 , so that the rotation operation of the key K in the direction returning to the “LOCK” position is locked. 
         [0070]    As shown in  FIG. 6B , in case that a shift lever of a vehicle is operated to a shift position of “P (parking)”, the supply of driving current to the holding solenoid  33  is blocked, thereby the rotation restraint of the link  34  is released. Accordingly, when the key K is operated from the “ACC” position to the “LOCK” position in this state, the taper surface  35   a  of the release link  35  runs upon an edge of the action surface  116   d  of the cam shaft  116 , thereby the arm part  34   c  of the link  34  on which elastic force acts toward the release link  35  by the torsion spring  37  is also rotated in conjunction therewith, thus the interlock state is released so that the rotation operation of the key K to the “LOCK” position is allowed. 
         [0071]    As explained above, in accordance with the interlock unit  30  of the embodiment, the rotation shaft part  34   b  for rotatably supporting the link  34  and the pin  36  penetrating through the rotation shaft part  34   b  are disposed on a line of force of the rotation operation force generated in the tangential direction of the cam shaft  116  operated by the key K. The rotation operation force from the cam shaft  116  is received at the rotation shaft part  34   b  and the pin  36 , thereby the burden of a load to the link  34  can be reduced. In addition, the arm part  34   c  of the link  34  is formed so as to have a shape extending linearly from the rotation shaft part  34   b  as a center, so that only compression load component acts on the arm part  34   c  without bending stress component. The link mechanism of the above-mentioned configuration is adopted as a reinforcement part of the holding solenoid  33 , so that as a material of the link  34  and the like, a resin having high resistance to a compression load such as PBT can be used instead of metal, so that high production costs can be reduced. 
         [0072]    In addition, according to the embodiment, such a structure is adopted, that the engaging projection part  31   b  is formed in one end part of the interlock unit  30 , and the engaging projection part  31   b  is engaged with the housing frame part  101   d  of the steering lock device  1  so that the interlock unit  30  is mounted. Thereby, in comparison with a conventional case that two mounting bolts are fastened, the mounting process of the interlock unit  30  can be simplified so as to reduce the production costs. 
         [0073]    In addition, according to the embodiment, such a structure is adopted, that the engaging projection part  31   b  that allows the interlock unit  30  to engage with the steering lock device  1  is formed in a side (the left side when viewed from the insertion direction of the key K) on which the rotation operation force acts, the rotation operation force being directed toward the direction in which the key K is returned to the “LOCK” position at the interlock state. By the above-mentioned structure for installing in the steering lock device  1 , the rotation operation force from the cam shaft  116  can be received on the surface of the housing frame part  101   d  of the steering lock device  1  instead of a conventional shear direction to the mounting bolts, thereby backlash, loose and the like that occur in the mounting part of the interlock unit  30  can be prevented, so that sufficient performance quality can be maintained. 
         [0074]    Although the invention has been described with respect to the specific embodiments for complete and clear disclosure, the appended claims are not to be thus limited but are to be construed as embodying all modifications and alternative constructions that may occur to one skilled in the art which fairly fall within the basic teaching herein set forth.