GB2518958A

GB2518958A - Steering lock device

Info

Publication number: GB2518958A
Application number: GB1413630.3A
Authority: GB
Inventors: Satoshi Sugihara
Original assignee: U Shin Ltd
Current assignee: U Shin Ltd
Priority date: 2013-08-09
Filing date: 2014-07-31
Publication date: 2015-04-08
Anticipated expiration: 2034-07-31
Also published as: DE102014111399A1; JP6168694B2; GB2518958B; DE102014111399B4; GB201413630D0; JP2015033993A

Abstract

A steering lock device with anti-theft deadlock mechanism actuated during destruction. A steering lock device 1 has a lock bolt 5 for engaging with a steering column 30. A lock bolt hanger 10 actuates the lock bolt 5 in response to a key actuated camshaft 11a. The steering lock has a two body parts 2, 3 connected in a pivotable manner. The body parts 2, 3 can be connected by a ball joint 6 within a spherical socket 3c such that if a destructive force is applied the body parts rotate relative to one another. An auxiliary deadlock 17 is triggered to lock within an engagement recess 5a of the steering lock bolt 5 in its locked position if there is movement or separation of the two body parts 2, 3: a hold pin 18 is normally resiliently held against a casing rib 4e but releases the deadlock 17 on relative rotation of the bodies. The pivot point for the ball joint 3a, 6 is the point of linkage between the lock bolt 5 and lock bolt hanger 10.

Description

STEERING LOCK DEVICE

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a steering lock device for locking a steering wheel of a vehicle to restrain its rotation when the vehicle is parked.

Description of the Related Art

For purposes of theft prevention, a vehicle is provided with a steering lock device for locking a steering wheel to restrain its rotation when the vehicle is parked. As such a steering lock device, there has been proposed a steering lock device including a deadlock mechanism for preventing a steering lock from being unlocked by an act of destruction. Specifically, when the steering lock device is destroyed, the deadlock mechanism holds a lock bolt engaged in a steering shaft in a locked position to thereby disable the lock bolt to be operated.

(Refer to Japanese Patent Application Publication No. Hei 7-032973, for example) Mi example of the steering lock device including the deadlock mechanism is illustrated in FIG. 8.

FIG. 8 is a cross-sectional view illustrating a state where a conventional steering lock device including a deadlock mechanism is locked. Specifically, in a steering lock device 101 illustrated in the FIG. 8, reference numeral 102 denotes a first body made of metal and fixed to a steering column (unillustrated) on a vehicle body side. A second body 103 made of resin is screwed or otherwise fastened to a lower portion of the first body 102, and an opening of the second body 103 is covered with a lid 104 made of resin. Also, a lock bolt 105 is accommodated in an actuation hole lO2a formed to vertically extend through the first body 102. The lock bolt 105 is inserted movably up and down while passing through the actuation hole lO2a. Meanwhile, a steering shaft 130 is provided with an engagement groove l3Oa formed in a portion of its outer periphery. The lock bolt 105 can move (move up and down) between a locked position in which the lock bolt 105 is engaged in the engagement groove 130a and an unlocked position in which the lock bolt 105 is disengaged from the engagement groove 130a.

In the lock bolt 105, an engagement recess portion 105a in a rectangular groove shape is formed at an intermediate height position of an outer periphery of the lock bolt 105, and a linkage recess portion lOSb in a transverse groove shape is formed to transversely extend through a lower end portion of the lock bolt 105.

On the other hand, a hanger 110, a camshaft 111 anda spring 112 are accommodated in a housing space of the second body 103 covered with the lid 104. An upper end portion of the hanger 10 is linked to the lower end portion of the lock bolt 105, the camshaft 111 forms an actuating mechanism for moving the hanger to the locked position or the unlocked position (i.e. up or down movement) , and the spring 112 biases the hanger 110 and the lock bolt 105 upward (i.e. toward the locked position) The hanger 110 is housed to extend vertically in the housing space in the second body 103. A linkage protrusion portion llOa formed on the upper end portion of the hanger 110 is engaged in the linkage recess portion 105b formed through the lower end portion of the lock bolt 105, and thereby, the upper end portion of the hanger 110 is linked to the lower end portion of the lock bolt 105. Then, the hanger 110 and the lock bolt 105 are biased upward (i.e. toward the locked position) by the spring 112 provided in compression between the lower end of the hanger 110 and an inner bottom surface of the second body 103.

Also, the camshaft ill forming the actuating mechanism is arranged with its length extending perpendicularly to the sheet face of FIG. 8, and a portion of the camshaft 111 is provided integrally with a cam lila. Then, the cam lila is engaged with a cam portion 11Gb provided in a lower end portion of the hanger 110. Here, when a driver inserts a key into a keyhole of a key cylinder (unillustrated) and turns the key, the camshaft 111 rotationally moves together with the key cylinder, and the cam lila formed integrally with the camshaft 111 actsonthecamportionll0bprovidedinthe iowerendportion of the hanger 110 thereby to move the hanger 110 and the lock bolt 105 linked to the hanger 110 upward or downward and thus move the lock bolt 105 to the locked position or the unlocked position.

Here, the steering lock device 101 illustrated in FIG. 8 is provided with a deadlock mechanism for holding the lock bolt 105 in the locked position even if an act of destruction aimed at vehicle theft occurs under a condition where the lock bolt 105 is in the locked position illustrated in FIG. 8 when a vehicle is parked. The deadlock mechanism includes a lock plate 117 which fits slidably in a fitting groove lO2b in a transverse groove shape formed in the first body 102, a hold pin 118 which is arranged with its length extending vertically and is to be engaged in and disengaged from a circular hole 117a formed in the lock plate 117, and a spring 119 which biases the hold pin 118 downward.

The lock plate 117 is slidable in the fitting groove 102b of the first body 102 perpendicularly to the sheet face of FIG. 8, and a planar configuration of the lock plate 117 includes a narrow-width portion having the circular hole 117a, and a wide-width portion (unillustrated) located frontward of the narrow-width portion on the sheet of FIG. 8 and having a greater width than the narrow-width portion. Then, the lock plate 117 is biased toward the front side of the sheet of FIG. 8 by a biasing means (unillustrated) such as a spring.

Also, the hold pin 118 is inserted and retained movably up and down in the first body 102 and the second body 1C3. Under a normal condition illustrated in FIG. 8 where an act of destruction does not occur, the hold pin 118 is maintained in the illustrated condition with its lower end abutting an engagement rib 104e of the lid 104, and restrains the lock plate 117 from moving with an upper end of the hold pin 118 passing through the circular hole 117a of the lock plate 117. Under this condition, the lock plate 117 is in a free position in which the lock plate 117 is entirely withdrawn in the fitting groove lO2b of the first body 102 and does not protrude into the actuation hole 102a. Thus, the lock plate 117 does not engage in the engagement recess portion 105a of the lock bolt 105, so that the lock bolt 105 can move without restraint between the locked position and the unlocked position.

In this connection, if the second body 103 is removed for purposes of theft under a condition where the vehicle is parked and thus the lock bolt 105 is in the locked position as illustrated in FIG. 8 and the steering shaft 130 is locked and restrained from rotating, a lower end portion of the hold pin 118 is disengaged from the engagement rib 104e of the lid 104, and thus the hold pin 118 moves downward by a bias force of the spring 119. Then, an upper end portion of the hold pin 118 gets cut of the circular hole li7a of the iock plate 117, and thus the lock plate 117 slides toward the back side of the sheet of FIG. 8 in the fitting groove 102b of the first body 102 by a bias force of the biasing means (unillustrated) When the lock plate 117 slides toward the back side of the sheet of FIG. 8 as mentioned above, a portion (i.e. the wide-width portion) of the lock plate 117 protrudes from the fitting groove 102b toward the lock bolt 105 (in a direction orthogonal to a movement direction of the lock bolt 105) and engages in the engagement recess portion 105a of the lock bolt 105, thereby to restrain the lock bolt 105 from moving toward the unlocked position and thus hold the lock bolt 105 in the locked position. As a result, the steering shaft 130 is maintained in the locked state so that steering operation cannot be performed, and thereby, the vehicle theft can be prevented.

Incidentally, the second body 103 is made of the resin for purposes of weight reduction, and deterioration in anti-theft characteristics due to the second body 103 made of the resin is compensated by the deadlock mechanism.

SUMMARY OF THE INVENTION

However, as illustrated in FIG. 9, when the second body 103 receives a strong shock from a lateral side by being struck from the lateral side for purposes of theft, the first body 102 is immovable because of being fixed to the steering column on the vehicle body side, whereas the second body 103 is moved and separated from the first body 102 in such a way as to rotate relative to the first body 102 about a point C on the opposite side from the side on which the shock is imposed. In this case, since the point C is far away from a point B (a point cf linkage between the lock bolt 105 and the hanger 110) , the hanger 110 is pressed downward as the second body 103 move to rotate about the point C, so that the lock bolt 105 moves toward the unlocked position (downward in FIG. 9) by being pulled by the hanger 110.

The movement amount of the lock bolt 105 is proportional to a distance between the point B and the point C. After slight movement of the lock bolt 105 toward the unlocked position, the lock plate 117 may not engage in the engagement recess portion 105a as illustrated in FIG. 9 even if the hold pIn 118 is disengaged from the engagement rib 104e and thus the deadlock mechanism is actuated. This is because of positional displacement between the lock plate 117 and the engagement recess portion 105a of the lock bolt 105. In this case, the lock bolt 105 can be operated to move from the locked position to the unlocked position. In this way, the lock bolt 105 cannot beheldinits lcckedstate, andthe steeringlockmaybeunlocked.

This may lead to the problem of degrading anti-theft characteristics.

The present invention has been made in view of the foregoing problem. An object of the present invention is to provide a steering lock device having anti-theft characteristics improved by actuating a deadlock mechanism reliably at the occurrence of an act of destruction.

In order to attain the above object, a first aspect of the present invention provides a steering lock device, including a first body fixed on a vehicle body side and internally accommodating a lock bolt movable between a locked position in which the lock bolt is engaged in a steering shaft and an uniocked position in which the lock bolt is disengaged from the steering shaft; a second body fixed to the first body and including a hanger linked to the lock bolt and an actuating mechanism for moving the hanger to the locked position or the unlocked position; a deadlock mechanism configured to lock the lock bolt in the locked position when there is a change in the position of the second body relative to the first body; a first fixing unit configllred to fix the second body to the first body; and a second fixing unit configured to support the second body rotatably on the first body when the first fixing unit is destroyed. A center of rotational movement of the second body in the second fixing unit sllbstantially coincides with a point of linkage between the lock bolt and the hanger in the locked position.

According to a second aspect of the present invention, in the first aspect, the second fixing unit includes a spherical ball joint provided in the first body and having a housing portion in which the lock bolt is housed movably in advancing and retracting directions, and a concave spherical attachment recess portion provided in the second body and holding the ball joint rotatably, and the point of linkage between the lock bolt and the hanger in the locked position is arranged substantially at a center position of the ball joint.

According to a third aspect of the present invention, in the second aspect, the first fixing unit includes a locking portion provided in any one of the ball joint and the attachment recess portion, and a locking hole which is provided in the other, and in which the locking portion is fitted, and the locking portion is deformable or movable by an impact on the secondbody.

According to the first aspect of the present invention, when the first fixing unit is destroyed due to the fact that the second body receives a strong shock at its lateral side portion, the second body is rotatably held on the first body by the second fixing unit. In this case, the center of rotational movement of the second body substantially coincides with the point of linkage between the look bolt and the hanger in the locked position. Thus, even if the second body rotationally moves relative to the first body, the hanger alone changes its direction, so that the lock bolt is restrained from moving toward the unlocked position by being pulled by the hanger. Thus, even if the rotational movement of the second body actuates the deadlock mechanism, the deadlock mechanism can hold the lock bolt in the locked position reliably thereby to restrain rotational operation of the steering shaft (a steering wheel) and hence improve anti-theft characteristics of a vehicle.

According to the second aspect of the present invention, the first body and the second body are linked together by the ball joint; therefore, even if a shock is imposed on the second body from any direction, position displacement beuween the center of rotational movement of the second body and the point of linkage between the lock bolt and the hanger is suppressed, so that the lock bolt is restrained from moving toward the unlocked position by being pulled by the hanger. Consequently, the deadlock mechanism can be actuated to hold the lock bolt in the locked position with higher reliability.

According to the third aspect of the present invention, the locking portion is fitted in the locking hole thereby to fix the second body to the first body; when a great shock is imposed on the second body from ontside, the locking portion becomes deformed or moves to release the fitting of the locking portion with the locking hole, and thus, the second body is unfixed from the first body, so that the deadlock mechanism is actnated reliably. Thus, the first fixing unit can be formed by a simple configuration of the locking portion and the locking hole fitting each other.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of a steering lock device according to the present invention.

FIG. 2 is a cross-sectional view of the steering lock device according to the present invention.

FIG. 3 is an exploded perspective view of the steering lock device according to the present invention.

FIG. 4 is a cross-sectional view taken along the line A-A of FIG. 1 (as being in a locked state) FIG. 5 is a cross-sectional view taken along the line A-A of FIG. 1 (as being in an unlocked state) FIG. 6 is a cross-sectional view illustrating how a deadlock mechanism operates when the steering lock device according to the present invention encounters an act of destruction.

FIG. 7 is a partial sectional view illustrating a modification of the steering lock device according to the present invention.

FIG. 8 is a cross-sectional view illustrating a conventional steering lock device as being in a locked state.

FIG. 9 is a cross-sectional view of assistance in explaining a problem which arises when a shock is imposed from outside on a second body of the conventional steering lock device.

DESCRIPTION OF THE EMBODIMENTS

Mi embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a side view of a steering lock device according to the present invention, FIG. 2 is a cross-sectional view of the steering lock device, FIG. 3 is an exploded perspective view of the steering lock device, FIG. 4 is a cross-sectional view taken along the line A-A of FIG. 1 (as being in a locked state) FIG. 5 is a cross-sectional view taken along the line A-A of FIG. 1 (as being in an unlocked state), and FIG. 6 is a cross-sectional view illustrating how a deadlock mechanism operates when the steering lock device according to the present invention encounters an act of destruction.

A steering lock device 1 according to the present invention locks or unlocks a steering wheel (unillustrated) to restrain or permit its rotation in connection with rotational operation of a key to start an engine. The steering lock device 1 includes a first body 2 made of metal and fixed to a steering column (unillustrated) on a vehicle body side, and a second body 3 made of resin and fastened to a lower portion of the first body 2, and an opening of the second body 3 is covered with a lid 4 made of resin in the same manner.

As illustrated in FIGS. 2 and 4 to 6, an actuation hole 2a is formed to extend vertically through the first body 2, and a lock bolt 5 is inserted and acconodated in the actuation hole 2a movably up and down while passing through the actuation hole 2a. Also, as illustrated in FIGS. 2 to 6, a lower end portion of the first body 2 is provided integrally with a spherical ball joint 6, and the ball joint 6 is provided integrally with locking portions 6a in the form of small protrusions, which protrude from the ball joint 6 at three locations on its outer periphery.

The lock bolt Scan move (move up and down) between a locked position in which the lock bolt 5 is engaged in an engagement groove 30a formed in a portion of an outer periphery of a steering shaft 30 as illustrated in FIG. 4 and an unlocked position in which the lock bolt 5 is disengaged from the engagement groove 30a as illustrated in FIG. 5. Also, an engagement recess portion 5a in a rectangular groove shape is formed in an outer periphery of the lock bolt 5 at its intermediate height position, and a linkage recess portion Sb in a transverse groove shape is formed to transversely extend through a lower end portion of the lock bolt 5.

On the other hand, as illustrated in FIGS. 2 and 3, the second body 3 includes a main body portion 3A in the form of a rectangular container, and a cylindrical key cylinder attachment portion 3B extending horizontally integrally from the main body portion 3A, and the key cylinder attachment portion 3B has a key cylinder 7 attached thereto as illustrated in FIG. 2. Then, as illustrated in FIG. 2, an output shaft 8 extends horizontally from a central portion of one end of the key cylinder 7.

Then, the lid 4 is attached to an opening of the main body portion 3A of the second body 3 to cover the opening, and, as illustrated in FIG. 3, the lid 4 is provided integrally with bosses 4A protruding therefrom at two locations on its inner surface, and a screw insert-through hole 4a in a circular hole shape is formed in each of the bosses 4A. Also, screw holes 3a are formed in the main body portion 3A of the seoond body 3 at two locations, respectively, corresponding to the screw insert-through holes 4a of the lid 4, and the lid 4 is mounted to the second body 3 by screwing a total of two screws 9 (see FIG. 1) passing through the screw insert-through holes 4a into the screw holes 3a, respectively, of the second body 3, and the lid 4 forms a housing space together with the main body portion 3A of the second body 3 (see FIG. 2) As illustrated in FIG. 2, the housing space formed in the main body portion 3A of the second body 3 accommodates a hanger whose upper end portion is linked to the lower end portion of the lock bolt 5, a camshaft 11 which forms an actuating mechanism for effecting movement (i.e. up or down movement) of the hanger 10 to the locked position or the unlocked position, a spring 12 which biases the hanger 10 and the lock bolt 5 upward (i.e. toward the locked position), a spring 13 which biases the key cylinder 7 rightward in FIG. 2, and a first bevel gear 14 and a second bevel gear 15 having a meshing engagement with each other.

The hanger 10 is accommodated to vertically extend in the second body 3, and a linkage protrusion portion iOa bent at right angles is formed on the upper end portion of the hanger 10. The linkage protrusion portion lOa is engaged in the linkage recess portion Sb formed through the lcwer end portion of the lock bolt 5, and thereby, the upper end portion of the hanger 10 is linked to the lower end portion of the lock bolt 5. The linkage protrusion portion ba of the hanger 10 is formed substantially in a spherical shape, and thus, the lock bolt 5 is linked to the hanger 10 rotatably around a point of linkage between the lock bolt S and the hanger 10 (a center point of the linkage protrusion portion ba) . Then, the hanger 10 and the lock bolt are normally biased upward (i.e. toward the locked position) by the spring 12 provided in compression between a lower end of the hanger 10 and an inner bottom surface of the second body 3.

Also, the camshaft 11 which forms the actuating mechanism is arranged with its length extending in a left-right direction in FIG. 2, and one end of the camshaft U (an end thereof on the right-hand side of FIG. 2) is linked to the output shaft 8 extending from the key cylinder 7. Then, a portion of the camshaft II is provided integrally with a cam ila, and the cam ha is engaged with a block-shaped cam portion lOb provided in a lower end portion of the hanger 10 as illustrated in FIGS. 4 to 6. Here, the camshaft 11 rotationally moves by a driver inserting a key (unillustrated) into a keyhole of the key cylinder 7 and turning the key, and the cam ha formed integrally with the camshaft 11 acts on the cam portion lOb provided in the lower end portion of the hanger 10 thereby to move the hanger and the lock bolt 5 linked to the hanger 10 upward or downward and thus move the lock bolt 5 to the locked position or the unlocked position.

As illustrated in FIG. 2, the first bevel gear 14 is bound to the camshaft 11, the second bevel gear 15 mating with the first bevel gear 14 is bound to an upper end of a rotary shaft 16 vertically inserted through and supported inabottomportion of the main body portion 3A of the second body 3, and the rotary shaft 16 is linked to an ignition switch (a rotary type switch) (unillustrated) . Incidentally, as illustrated in E'TG. 3, the inner surface of the lid 4 is provided integrally with plural first gear retainers 4b, second gear retainers 4c and cam retainers 4d protruding therefrom.

In this connection, concave hemispherical attachment recess portions 30, 43 are formed in the second body 3 and the lid 4, respectively, and the ball joint 6 formed integrallywith the lower end portion of the first body 2 is fitted and held in the attachment recess portions 30, 43. Here, as illustrated in FIGS. 2 and 4 to 6, a housing portion 6A housing the lock bolt 5 in such a manner that the lock bolt 5 can move in advancing and retracting directions (move up and down) is formed inside the ball joint 6.

As mentioned previously, the ball joint 6 is provided integrally with the small locking portions 6a in the form of the protrusions, which protrude from the ball joint 6 at the three locations on its outer peripheral surface, and locking holes Sb are formed in an inner peripheral surface of the attachment recess portion 30 of the second body 3 at three locations (locations corresponding to the locking pcrtions 6a of the ball joint 6) . Under a normal condition illustrated in FIG. 2 (a condition where a strong shock is not imposed on the second body 3, as distinct from a shock-imposed condition to be described later) , the locking portions 6a of the ball joint 6 are fitted in the looking holes 3b formed in the attachment recess portion 30 of the second body 3 thereby to restrain the second body 3 from rotationally moving relative to the first body 2 and thus fix the second body 3 to the first body 2. Here, the locking portions 6a and the locking holes 3b fitting each other form a first fixing unit configured to fix the second body 3 to the first body 2, and the ball joint 6 and the attachment recess portions 30, 4B of the second body 3 and the lid 4 holding the ball joint 6 form a second fixing unit configured to support the second body 3 rotatably on the first body 2 when the first fixing unit is destroyed as described iater.

Thus, in the embodiment, a center of rotational movement of the second body 3 in the second fixing unit is a center point of the ball joint 6, and a configuration is such that the center point of the bail joint 6 coincides with the point of linkage between the lock bolt 5 and the hanger 10 in the locked position as illustrated in FIGS. 2 and 4.

The steering lock device 1 according to the present invention is provided with a deadlock mechanism for holding the lock bolt 5 in the locked position even if an act of destruction for purposes of vehicle theft occurs under a condition where the lock bolt 5 is in the locked position illustrated in FIGS. 1, 2 and 4 when a vehicle is parked.

As illustrated in FIG. 4, the deadlock mechanism includes a lock plate 17 fitted and held in a fitting groove 2b in the shape of a transverse groove formed in the first body 2, a hold pin 18 with its length extending vertically, which is engaged in and disengaged from a hole 17a formed in the lock plate 17, and a spring 19 which normally biases the hold pin 18 downward.

The lock plate 17 is slidably fitted and held in the fitting groove 2b of the first body 2 perpendicularly to the sheet face of FIG. 4, and a planar configuration of the lock plate 17 includes a narrow-width portion having the circular hole 17a, and a wide-width portion (unillustrated) located frontward of the narrow-width portion on the sheet of FIG. 4 andhaving a greaterwidth than the narrow-widthportion. Then, the lock plate 17 is biased toward the front side of the sheet of FIG. 4 by a biasing means (unillustrated) such as a spring.

Also, the hold pin 18 is inserted through and retained movably up and down in the first body 2 and the second body 3.

Under a normal condition illustrated in FIG. 4 where an act of destruction does not occur, the hold pin 18 is maintained in the illustrated condition by its lower end abutting an engagement rib 4e of the lid 4, and the hold pin 18 extends at its upper end through the hole 17a of the lock plate 17 thereby to restrain sliding movement of the lock plate 17. Under this condition, the lock plate 17 is in a free position in which the lock plate 17 is entirely withdrawn in the fitting groove 2b of the first body 2 and does not extend out into the actuation hole 2a, and thus, the lock plate 17 does not engage in the engagement recess portion 5a of the lock bolt 5, so that the lock bolt 5 can move without restraint between the locked position and the unlocked position.

Next, description will be given with regard to unlocking operation and locking operation of the steering lock device 1 configured as described above.

1) Unlocking Operation When the driver inserts the key (unillustrated) into the keyholeofthe keycylinder 7underaconditionwhere thevehicle is stopped and the lock bolt 5 is in the locked position as illustrated in FIGS. 2 and 4 and the steering shaft 30 is locked and restrained from rotating, plural turiblers (unillustrated) provided in the key cylinder 7 are actuated (withdrawn) thereby to render rotational operation of the key possible. When llnder this condition the driver rotationally moves the key clockwise, this rotation is transmitted from the output shaft 8 of the key cylinder 7 to the camshaft 11, and the cam ha formed integrally with the camshaft 11 rotates. Then, the hanger 10 provided with the cam portion lOb engaged with the cam lla is pressed downward, and the lock bolt 5 linked to the hanger SO is also pressed downward, so that the lock bolt 5 moves to the unlocked position as illustrated in FIG. 5. Thus, when the lock bolt 5 moves to the unlocked position, the lock bolt 5 is disengaged from the engagement groove 30a of the steering shaft 30, thus enabling rotational operation (steering operation) of the steering shaft (the steering wheel) Also, the first bevel gear 14 rotates together with the oamshaft 11, and this rotation is transmitted via the seoond bevel gear 15 to the rotary shaft 16, and thus, the ignition switch (unillustrated) linked to the rotary shaft 16 is switched to perform the switching of the power state of the vehicle and actuate a starter motor and do the like.

2) Locking Operation When the key is rotationallymoved collnterclockwise under a condition where the lock bolt 5 is in the unlocked position as illustrated in FIG. 5, this rotation is transmitted from the output shaft B of the key cylinder 7 to the camshaft 11, and the cam ila formed integrally with the camshaft 11 rotates.

Then, the hanger 10 moves llpward along the oam ila of the oamshaft 11 by an upward biasing force of the spring 12, and the lock bolt 5 linked to the hanger 10 also moves upward to the looked position as illustrated in FIG. 4, and thus, an upper endportion of the lock bolt 5 is engaged in the engagement grocve 30a of the steering shaft 30 thereby to lock the steering shaft 30 and restrain its rotation and render the steering operation impossible, thus preventing the theft of the parked vehicle.

Also, the first bevel gear 14 rotates in reverse direction together with the camshaft 11, and this rotation is transmitted via the second bevel gear 15 to the rotary shaft 16, and thus, the ignition switch (unillustrated) linked to the rotary shaft 16 is switched in reverse direction.

When the second body 3 receives a strong shock from a lateral side as illustrated in FIG. 6 due to the fact that the second body 3 of the steering lock device 1 is struck hard from the lateral side for purposes of vehicle theft, the three locking portions 6a protruding from the ball joint 6 of the first fixing unit become deformed to thus release the fitting of the locking portions 6a with the locking holes 3b on the second body 3 side and thereby unfix the second body 3 from the first body 2, so that the second body 3 rotaionally moves around the center point of the ball joint 6 as illustrated in FIG. 6.

When the second body 3 rotationally moves relative to the first body 2 as mentioned above, in the deadlock mechanism, the hold pin 18 is disengaged from the engagement rib 4e of the lid 4, and thus, the hold pin 18 moves downward by a bias force of the spring 19, and an upper end portion of the hold pin 18 is withdrawn from the hole 17a of the lock plate 17. Then, the lock plate 17 is released from its free state, the lock plate 17 slides toward the back side of the sheet of FIG. 6 in the fitting groove 2b of the first body 2 by a spring (unillustrated) and a portion (i.e. the wide-width portion) of the lock plate 17 protrudes from the fitting groove 2b toward the lock bolt and engages in the engagement recess portion 5a formed in the lock bolt 5. consequently, the lock bolt 5 is restrained from moving toward the unlocked position and the lock bolt 5 is held in the locked position, and thus, the steering is maintained in the locked state, so that the vehicle theft can be prevented.

Thus, in the embodiment, a configuration is such that the center point of the ball joint 6 as the center of rotational movement of the second body 3 coincides with the point of linkage between the lock bolt 5 and the hanger 10 in the locked position.

Thus, even if the second body 3 rotationally moves relative to the first body 2 as illustrated in FIG. 6, the hanger 10 alone changes its direction, so that the lock bolt 5 is restrained from moving toward the unlocked position by being pulled by the hanger 10. Thus, even if the rotational movement of the second body 3 actuates the deadlock mechanism, there is no position displacement between the lock plate 17 and the engagement recess portion 5a of the lock bolt 5 in the deadlock mechanism, and the lock plate 17 engages in the engagement recess portion 5a of the lock bolt 5 reliably. Consegnently, the lock bolt 5 can be held in the locked position reliably thereby to restrain the rotational operation of the steering shaft 30 (the steering wheel) and thus improve anti-theft characteristics of the vehicle.

Also, in the embodiment, the first body 2 and the second body 3 are linked together by the ball joint 6; therefore, even if a shock is imposed on the second body 3 from any direction, position displacement between the center of rotational movement of the second body 3 and the point of linkage between the lock bolt 5 and the hanger 10 is eliminated, so that the lock bolt can be prevented from moving toward the unlocked position by being pulled by the hanger 10. Thus, the deadlock mechanism can be actuated to hold the lock bolt 5 in the locked position with higher reliability.

Further, in the embodiment, the locking portions 6a of the ball joint 6 which forms the first fixing unit are fitted in the locking holes 3b of the second body 3 thereby to fix the second body 3 to the first body 2. When a great shock is imposed on the second body 3 from outside, the locking portions 6a become deformed to release the fitting of the locking portions 6a with the locking holes 3b, and thus, the second body 3 is unfixed from the first body 2, so that the deadlock mechanism is actuated reliably. Thus, the first fixing unit can be formed by a simple configuration of the locking portions 6a and the locking holes 3b fitting each other.

Incidentally, in the embodiment, the center point of the ball joint 6 as the center of rotational movement of the second body 3 coincides with the point of linkage between the lock bolt and the hanger 10 in the locked position; however, the center point and the point of linkage are not limited to precisely coinciding with each other, and a slight displacement therebetween is allowed.

Specifically, as illustrated in FIG. 4, it is necessary that a gap Y be set smaller than an engagement allowance X (Y < X) in order for the deadlock mechanism to hold the lock bolt in the locked position, where X represents an allowance for engagement of the lock bolt 5 with the engagement groove 30a of the steering shaft 30, and Y represents a gap between the lock plate 17 and the engagement recess portion 5a of the lock boltS. Here, when the second body 3 rotationally moves around the center point of the ball joint 6, even if the point of linkage between the hanger 10 and the lock bolt 5 is displaced from the center point of the ball joint 6 within a range such that the lock bolt 5 is not actuated to move toward the unlocked position by an amount equal to or more than the gap Y, the lock plate 17 can be engaged in the engagement recess portion 5a of the lock bolt 5 reliably.

Incidentally, in the embodiment, the locking portions 6a which form the first fixing unit are provided on the bali joint 6, and the locking holes 3b in which the locking portions 6a are fitted are provided on the second body 3 side; however, contrary to this, the locking portions may be provided on the second body 3 side, and the locking holes may be provided on the ball joint 6 side.

Also, as illustrated in FIG. 7, a configuration may be adopt as given below; specifically, the first fixing unit is formed of steel bails 21 biased radially outward by springs 20 provided in compression in plural circular holes 6b formed in the ball joint 6, and the plural locking holes 3b forned in the attachment recess portion 3C of the second body 3, and the steel bails 21 are engaged in the locking holes 3b thereby to fix the second body 3 to the first body 2. Adoption of such a configuration can prevent the following disadvantage from arising; specifically, part replacement becomes necessary when the locking portions 6a illustrated in FIGS. 2 and 3 are crushed by mistake during assembly. Also, even if the steel balls 21 are withdrawn in the circular holes 6b and thus there is a position displacement between the first body 2 and the second body 3, it is not necessary to replace parts again, and the positionimg of the first body 2 and the second body 3 can be set -Further, in the embodiment, the second body 3 and the lid 4 are made of a resin material; however, the second body 3 and the lid 4 may be made of a metal material such as magnesium.

Claims

What is claimed is: 1. A steering lock device comprising: a first body fixed on a vehicle body side and internally accommodating a lock bolt movable between a locked pcsition in which the lock bolt is engaged in a steering shaft and an unlocked position in which the lock bolt is disengaged from the steering shaft; a second body fixed to the first body and including a hanger linked to the lock boit and an actuating mechanism configured to move the hanger to the locked position or the unlocked position; a deadlock mechanism configured to lock the lock bolt in the locked position when there is a change in the position of the second body relative to the first body; a first fixing unit configured to fix the second body to the first body; and a second fixing unit configured to support the second body rotatably on the first body when the first fixing unit is destroyed, wherein a center of rotational movement of the second body in the second fixing unit substantially coincides with a point of linkage between the lock bolt and the hanger in the locked position.
2. The steering lock device according to claim 1, wherein the second fixing unit includes a spherical ball joint provided in the first body and having a housing portion in which the lock bolt is housed movably in advancing and retracting directions, and a concave spherical attachment recess portion provided in the second body and holding the bail joint rotatabiy, and the point of linkage between the lock bolt and the hanger in the locked position is arranged substantially at a center position of the ball joint.
3. The steering lock device according to claim 2, wherein the first fixing nnit incindes a locking portion provided in any one of the ball joint and the attachment recess portion, and a locking hole which is provided in the other, and in which the locking portion is fitted, and the locking portion is defformabie or movable by an impact on the second body.