Abstract:
A steering lock device  10  includes a movable member  32  that blocks an engagement groove  30  on a rotor  18  to prevent a lock lever  28  from re-engaging with the engagement groove  30  once engagement of the lock lever  28  with the engagement groove  30  is released with activation of a solenoid  26  and that terminates the prevention of the re-engagement when the rotor  18  is pulled forward. In this device, the rotor  10  is prevented from being unnecessarily locked, without requiring long-term activation of the solenoid.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a steering lock device for use in a vehicle such as a motorcar. 
     It has been known that steering lock devices in which steering is unlocked and start of an engine is permitted on the basis of a judgment on normality of a user with an electronic authenticating function using an electronic key may have a knob for turning a cylinder lock without requiring a mechanical key. In some steering lock devices of this type, electronic authentication is executed with detection of a push on the knob by a detector, an actuator that has locked a turn of a cylinder lock is activated after the authentication is verified, and this activation permits the cylinder lock to be turned and permits the steering to be unlocked. 
     In the steering lock device of the above-mentioned type, however, the activation of the actuator is terminated with elapse of a predetermined period of time, and there is a possibility that the cylinder lock may be locked again if the cylinder lock is left for a moment without being turned after electronic authentication with a push on the knob. For prevention of this trouble, the actuator has to be kept activated for a long time, and a problem of an increase in electric power consumption is thereby caused. 
     Once the cylinder lock is turned with the knob from a lock position, through an ACC position and an ON position, to a start position and is thereafter returned to the lock position, the cylinder lock gets locked and cannot be turned immediately to the ACC position. In order to turn again the cylinder lock to the ACC position, therefore, the knob has to be pulled in the lock position and then has to be pushed again and the electronic authentication has to be executed afresh. 
     Moreover, there is a steering lock device in which an engine having been started once and then stalled cannot be restarted without return of the cylinder lock to the lock position in order to prevent a double starting by a starter. When the engine is stalled accidentally, therefore, a series of steps beginning with the electronic authentication have to be taken over again and restart of the engine is extremely troublesome. 
     SUMMARY OF THE INVENTION 
     In order to solve the above problems, the present invention provides a steering lock device comprising 
     a turning member having an engagement groove formed on an outer circumferential portion thereof, 
     a body for housing the turning member so that the turning member can be moved in backward and forward directions and can be turned, 
     a detecting section for detecting a backward push of the turning member, 
     a control section that executes electronic authentication in cooperation with portable equipment, upon receiving a detection signal from the detecting section, and that transmits an activation signal to an actuator after verification of the authentication, and 
     a lock member that is activated by the actuator and that engages with the engagement groove of the turning member so as to prevent the turning member from being turned; 
     wherein a movable member is provided that blocks the engagement groove to prevent the lock member from reengaging with the engagement groove once engagement of the lock member with the engagement groove of the turning member is released with activation of the actuator and that terminates the prevention of the re-engagement when the turning member is pulled forward. 
     In the steering lock device according to the present invention, the movable member may be movably provided in the engagement groove of the turning member and be connected to the turning member through a biasing member, so that a backward push of the turning member causes the movable member to be biased backward by the biasing member and to block the engagement groove after release of engagement of the lock member with the engagement groove and so that a forward pull of the turning member causes the movable member to be pulled and moved with the turning member and to open the engagement groove to allow engagement of the lock member with the engagement groove. 
     In accordance with the steering lock device of the present invention, the turning member is prevented from being locked again unless being pulled out once electronic authentication is executed with a push on the turning member and once the turning member is unlocked with the activation of the lock member by the actuator. Therefore, the actuator does not have to be activated for a long time and thus electric power consumption can be reduced. 
     With this steering lock device having a function of preventing double starting by a starter it is no longer necessary to perform the troublesome steps of re-starting the engine in case of an accidental engine stall or the like, that is, the necessity to repeat the steps beginning with the electronic authentication with a pull and a re-push of the turning member. 
     When the lock member moves out of the engagement groove of the turning member, the movable member biased by the biasing members slips under the lock member and thus prevents the lock member from reentering into the engagement groove of the turning member. In this manner, the turning member can be prevented from being unnecessarily locked, with a simple configuration. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will be further described with reference to the accompanying drawings wherein like reference numerals refer to like parts in the several views, and wherein: 
     FIG. 1 is a longitudinal sectional view of a steering lock device according to the present invention; 
     FIG. 2 is a cross-sectional view of the steering lock device of FIG. 1; 
     FIG. 3 is a partially enlarged view of FIG. 1; 
     FIG. 4 is a partially enlarged view of FIG. 1; 
     FIG. 5 is a longitudinal sectional view of the steering lock device in which a knob has been pushed; 
     FIG. 6 is a partially enlarged view of FIG. 5; 
     FIG. 7 is a partially enlarged view of FIG. 5; and 
     FIG. 8 is a longitudinal sectional view of the steering lock device in which a mechanical key has been inserted. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1 shows a longitudinal section of a steering lock device  10  as one embodiment of the present invention, taken along backward and forward directions. In FIG. 1 (ditto for FIGS.  5  and  8 ), for convenience the right side will be referred to as “fore” and the left side will be referred to as “back”. 
     The steering lock device  10  has a generally cylindrical body  12  formed of metal such as aluminum in one piece. In a fore side of the body  12  is installed a cylinder lock  14 . The cylinder lock  14  is composed of a cylindrical cylinder outer  16  that is fixed in the body  12 , a cylindrical rotor (a turning member)  18  that is accommodated in the cylinder outer  16  so as to be capable of moving in the backward and forward directions and turning, and a columnar cylinder  20  that is accommodated in the rotor  18  so as to be capable of turning. 
     Inside the cylinder  20 , a plurality of (ten in this embodiment) plate-like tumblers  22  are arranged at uniform intervals along a direction of an axis of the cylinder  20 . The tumblers  22  are biased, by springs (not shown), in directions that are orthogonal to the direction of the axis of the cylinder  20  and that are different alternately. End portions of the tumblers  22  biased by the springs respectively protrude from both sides of an outer circumferential surface of the cylinder  20  when a mechanical key is not inserted in a keyhole  14   a  (see FIG. 2) of the cylinder lock  14 . The protruded end portions of the tumblers  22  engage with lock grooves  18   a  formed on an inner circumferential surface of the rotor  18 . This engagement prevents the cylinder  20  from turning in the rotor  18 , and makes the cylinder  20  capable of turning integrally with the rotor  18  on condition that the rotor  18  is permitted to turn. When the mechanical key is inserted into the keyhole  14   a  of the cylinder lock  14 , the tumblers  22  move toward the inside of the cylinder  20  and the protruded end portions of the tumblers  22  withdraw from the outer circumferential surface of the cylinder  20 . The withdrawal of the tumblers  22  releases the engagement between the tumblers  22  and the lock grooves  18   a  of the rotor  18  and permits the cylinder  20  to be turned to a lock position, an ACC position, an ON position, and a start position in the rotor  18 . 
     A knob  24  is attached to a fore end portion of the cylinder  20 . The knob  24  has a slit-like inner space and the mechanical key can be inserted through the inner space into the keyhole  14   a  of the cylinder  20 . On condition that the cylinder  20  can be turned in the rotor  18 , the cylinder  20  can be turned to the lock position, the ACC position, the ON position, and the start position with a turn of the knob  24  by a user. On condition that the rotor  18  is permitted to be turned in the cylinder outer  16  as will be described later, the rotor  18  together with the cylinder  20  can be turned to the lock position, the ACC position, the ON position, and the start position with a turn of the knob  24  by a user. 
     To an upper portion of the body  12  is fixed a solenoid  26  as an actuator. On a plunger  26   a  of the solenoid  26  is installed a lock lever (a lock member)  28 . When the solenoid  26  is not activated, the lock lever  28  is in a position shown in FIG.  1 . When the solenoid  26  is activated, the lock lever  28  is lifted up by the plunger  26   a  of the solenoid  26 . 
     As shown in FIGS. 1 and 3, an engagement groove  30  is formed on an outer circumferential portion on the backside of the rotor  18 . When the solenoid  26  is not activated, an edge portion of the lock lever  28  is engaged with the engagement groove  30 . The engagement prevents the rotor  18  from being turned. 
     In the engagement groove  30  of the rotor  18 , a movable member  32  is slidably provided. The movable member  32  is connected to the rotor  18  through a spring (biasing member)  34 . In a state shown in FIG. 1 (that is, a state in which the rotor  18  has not been pushed backward), the spring exerts neither biasing forces nor tractive forces on the movable member  32 . When the rotor  18  is pushed and is moved backward as shown in FIG. 4, the spring  34  is compressed and the movable member  32  is thereby biased backward. It is noted that the biasing member connected to the movable member  32  is not limited to a spring but may be an elastic element of rubber or the like. 
     Again referring to FIG. 1, a shaft  40  formed integrally with a cam  42  is connected to a rear end portion of the cylinder  20 . A lock shaft  44  that is generally shaped like a bracket and that is biased by a spring (not shown) is in contact with the cam  42 . With this arrangement, a turn of the cylinder lock  14  from the lock position to the ACC position causes the shaft  40  and the cam  42  to turn together and causes the lock shaft  44  to move toward innermost in FIG.  1 . As a result, a tip end portion of the lock shaft  44  comes off from a recess on a steering shaft (not shown) and steering lock is released. 
     On a rear end portion of the body  12 , an ignition switch  50  is mounted. A conductive section  46  is provided on a rear end portion of the shaft  40  extending into the ignition switch  50 . Inside the ignition switch  50 , a switch (a detecting section)  52  is provided so as to face the conductive section  46 . When the knob  24  is pushed backward, the conductive section  46  on the rear end portion of the shaft  40  comes into contact with the switch  52  and backward travel of the cylinder  20  and the rotor  18  is thereby detected with the switch  52 . 
     The switch  52  is electrically connected to a controller (a control section)  54 . The controller  54  is electrically connected to the solenoid  26 . When receiving a detection signal from the switch  52 , the controller  54  executes electronic authentication by exchanging signals by radio with an electronic key (portable equipment)  56  the user has. After the authentication is verified, the controller  54  transmits an activation signal to the solenoid  26 . 
     Inside a fore side portion of the rotor  18 , a slider  60  is provided so as to be capable of sliding in a direction orthogonal to the direction of the axis of the cylinder  20 . The slider  60  has a key insertion hole  60   a  similar to the keyhole  14   a  of the cylinder  20 , and the key insertion hole  60   a  and the keyhole  14   a  of the cylinder  20  have different positions when the mechanical key is not inserted. 
     A slide pin  62  that is generally shaped like a character “L” is provided so as to be in contact with a lower portion of the slider  60 . The slide pin  62 , together with the rotor  18 , can be slid in the backward and forward directions. A recess  16   a  in which the slide pin  62  having slid backward is to fit is formed on an inner circumferential surface of the cylinder outer  16  and in the neighborhood of a position where the slide pin  62  is provided. Into the recess  16   a  protrudes a detection pin  66  of a key detection switch  64  installed in a lower portion of the body  12 . 
     Hereinbelow, operations of the steering lock device  10  with the above configuration will be described. 
     In a procedure by which a user starts an engine, as shown in FIG. 5, the knob  24  is initially pushed in a direction of an arrow A (i.e., backward direction) in a state in which the rotor  18  and the cylinder  20  are in the lock position. With this operation, the rotor  18 , the cylinder  20 , the slider  60 , the slide pin  62 , and the shaft  40  move backward together. At this time, as shown in FIG. 4, the backward movement of the rotor  18  causes the spring  34  to be compressed and the movable member  32  is biased against the lock lever  28  by the compressed spring  34 . 
     In addition, the push of the knob  24  causes the conductive section  46  on the rear end of the shaft  40  to come into contact with the switch  52 . The switch  52  thus detects the backward push of the knob  24  and the rotor  18  and then transmits a detection signal to the controller  54 . The controller  54  having received the detection signal transmits radio waves to the electronic key  56  the user has, receives a radio signal transmitted from the electronic key  56  in response to the radio waves, and thereby executes electronic authentication. After the authentication is verified, the controller  54  transmits an activation signal to the solenoid  26 . 
     The solenoid  26  is activated by the activation signal from the controller  54  so as to retract the plunger  26   a . The lock lever  28  attached to the plunger  26   a  is thereby lifted up, the engagement of the lever  28  with the engagement groove  30  of the rotor  18  is released, and the rotor  18  is permitted to be turned. Simultaneously, as shown in FIG. 6, the movable member  32  biased by the spring  34  moves, slips under the lock lever  28  and thus blocks the engagement groove  30 . 
     The activation of the solenoid  26  is terminated with elapse of a predetermined period of time, and the plunger  26   a  then protrudes from the solenoid  26  to lower the lock lever  28 . As shown in FIG. 7, however, the engagement groove  30  of the rotor  18  has been blocked by the movable member  32 , and therefore the lock lever  28  comes into contact with a top of the movable member  32  and is prevented from re-engaging with the engagement groove  30 . 
     It is noted that a top surface of the movable member  32  is configured so as to be flush with an outer circumferential surface of the rotor  18  where the engagement groove  30  is formed and therefore the lock lever  28  in contact with the top of the movable member  32  never hinders a turn of the rotor  18 . 
     In this state, the user turns the knob  24  to turn the cylinder  20  and the rotor  18  from the lock position, through the ACC position and the ON position, to the start position, activates the ignition switch  50  by means of the shaft  40 , and thereby starts the engine. When the cylinder  20  and the rotor  18  turn from the lock position to the ACC position, the shaft  40  and the cam  42  also turn with the cylinder  20  and the rotor  18 , and the turn of the cam  42  causes the movement of the lock shaft  44 , the tip end portion of the lock shaft  44  thereby comes off from the recess on the steering shaft, so that steering lock is released. When the user takes a hand of the user off the knob  24  after the start of the engine, the cylinder  20 , the rotor  18 , and the knob  24  automatically return to the ON position. 
     In operation for stopping the engine, the user turns the knob  24  opposite to the direction in the operation for starting the engine and thereby turns back the cylinder  20  and the rotor  18  from the ON position through the ACC position to the lock position. When the cylinder  20  and the rotor  18  return to the lock position, the lock shaft  44  moves with a turn of the cam  42  and engages with the recess on the steering shaft so that steering is locked. At this time, the engagement groove  30  of the rotor  18  remains blocked with the movable member  32 , and therefore the lock lever  28  is prevented from engaging with the engagement groove  30  and the rotor  18  is not locked. For restarting the engine, accordingly, the knob  24  can be only turned instantly to turn the rotor  18  and the cylinder  20 . 
     When the user pulls the knob  24  in a direction of an arrow B as shown in FIG. 5 in a state in which the cylinder  20  and the rotor  18  have been returned to the lock position with the knob  24 , the cylinder  20 , the rotor  18 , and the shaft  40  move forward. At this time, the movable member  32  having been in the status shown in FIG. 7 is pulled forward through action of the spring  34  connected to the rotor  18  and shifts to an initial position (i.e., status shown in FIG.  3 ). The shift of the movable member  32  terminates the status in which re-engagement of the lock lever  28  with the engagement groove  30  is prevented. That is, as shown in FIG. 3, the shift of the movable member  32  makes the engagement groove  30  open, and the lock lever  28  having moved out of contact with the movable member  32  descends and re-engages with the engagement groove  30 . The rotor  18  is locked in this manner. 
     On the other hand, the steering lock device  10  can be operated not only with the knob  24  but also with a mechanical key. When the mechanical key is attempted to be inserted into the keyhole  14   a  (see FIG. 2) of the cylinder  20  through the slit-like inner space in the knob  24 , the mechanical key  2  can not be inserted fully into the cylinder  20 , because the key insertion hole  60   a  of the slider  60  and the keyhole  14   a  of the cylinder  20  are in different positions and the slider  60  is prevented from being slid downward due to a presence of the slide pin  62  between the slider  60  and the cylinder outer  16 , as shown in FIG.  1 . 
     When the mechanical key  2  is pushed on condition that a tip end portion of the mechanical key  2  has been inserted to a shallow depth in the keyhole  14   a  of the cylinder  20 , the slider  60 , the slide pin  62 , the cylinder  20 , and the rotor  18  move backward together as shown in FIG.  8 . With this movement, the slide pin  62  comes into the recess  16   a  of the inner circumferential surface of the cylinder outer  16  and thereby allows the slider  60  to slide in the downward direction (the direction orthogonal to the axis of the cylinder  20 ). As a result, the key insertion hole  60   a  of the slider  60  coincides with the keyhole  14   a  of the cylinder  20  and the mechanical key  2  can fully be inserted into the cylinder  20 . 
     The slide pin  62  comes into the recess  16   a  of the inner circumferential surface of the cylinder outer  16  and thereby pushes the detection pin  66  of the key detection switch  64 , so that the insertion of the mechanical key  2  is detected by the key detection switch  64 . Use of the detection of the insertion of the key is made for a warning for preventing the key from being left behind or the like. 
     Release of steering lock, release of the rotor  16  by electronic authentication, functions of the movable member  32 , and the like in operations with use of the mechanical key  2  are the same as those in the operations with use of the knob  24  that have been described above, and duplicative description on those is therefore omitted. On condition that the rotor  18  has been unlocked with the activation of the solenoid  26 , however, a turn of the mechanical key  2  does not cause a turn of the rotor  18  but only causes a turn of the cylinder  20  because the slide pin  62  is in engagement with both the rotor  18  and the cylinder outer  16 . 
     At this time, control with the controller  54  may be performed so that the electronic authentication described above is not executed and so that the solenoid  26  is not activated on condition that the insertion of the key has been detected by the key detection switch  64 . With this arrangement, the lock lever  28  that remains in engagement with the engagement groove  30  keeps the rotor  18  locked and a turn of the mechanical key  2  causes only the cylinder  20  to turn. 
     Although the present invention has been fully described by way of examples with reference to the accompanying drawings, it is to be noted that various changes and modifications will be apparent to those skilled in the art. Therefore, unless otherwise such changes and modifications depart from the scope of the present invention, they should be construed as being included therein.