Blocking device for a motor vehicle steering shaft

The invention relates to a device for locking the steering spindle of a motor vehicle against rotation by means of a locking pin which interacts with locking recesses of the steering spindle and which can be moved back and forth radially between the blocking axis and the release position by means of a reciprocating control element With a laterally protruding pin into a spiral groove of the control member which winds on the end side of the control member adjacent to the locking bolt about its axis of rotation.

Such a device for locking the steering spindle of a motor vehicle so that it can no longer be rotated is known. The locking bolt is designed in two parts and is provided with a screw compression spring against which the locking bolt part interacting with the locking recesses of the steering spindle and the locking bolt part cooperating with the control member can be pushed together when the control element is rotated into the position corresponding to the blocking position of the locking bolt The locking bolt part which interacts with the steering spindle can not enter into a locking recess of the steering spindle because the steering spindle is not in such a rotational position in which one of its locking recesses is aligned with this locking bolt part. The pin, which is provided on the other locking bolt part and engages in the spiral groove of the control member, constitutes an immovable lateral projection of this locking bolt part. The control member is designed as a circular disk which can be rotated back and forth by means of a closing cylinder. The second-part locking bolt design with a screw compression spring is comparatively complex and susceptible to faults (DE-A-506 781).

In a similar known device for locking the steering spindle of a motor vehicle against turning, a one-piece locking pin is provided whose laterally projecting pin is fixedly connected to the locking bolt and extends through a spiral-shaped slot of a circular control disk which is rotated back and forth by means of a closing cylinder Can The control disc can only be rotated into the position corresponding to the blocking position of the locking pin when a locking recess of the steering spindle is aligned with the locking bolt and the locking bolt can enter the locking recess in order to assume its blocking position. US Pat. No. 1,786,186.

The invention is based on the object of providing a device of the type indicated at the outset, which is distinguished by a simple and inexpensive locking pin which is possible in every respect in terms of ease, but the control member can always be rotated into the position corresponding to the blocking position of the locking bolt Of the respective rotational position of the steering spindle.

This object is achieved in a device according to the invention by means of the features set out in the characterizing part of patent claim 1. Advantageous embodiments of the device according to the invention are specified in the remaining patent claims.

A preferred embodiment of the device according to the invention for locking the steering spindle of a motor vehicle against rotation is described by means of drawings, for example. It shows:<ul><li>FIG. 1 shows the longitudinal section along the line II in FIG. 2, the locking bolt being in its blocking position;</li><li>FIG. 2 is a view in the direction of the arrow II in FIG. 1 without housing, housing cover and printed circuit board, and without steering spindle; FIG.</li><li>FIG. 3 is a perspective view corresponding to the view of FIG. 2, the locking bolt being longitudinally cut; FIG.</li><li>FIG. 4 shows the longitudinal section along the line IV - IV in FIG. 5, the locking pin being in its release position;</li><li>FIG. 5 is a view in the direction of the arrow V in FIG. 4 without housing, housing cover and printed circuit board, and without steering spindle;</li><li>FIG. 6 is a perspective view corresponding to the view of FIG. 5, the locking bolt being longitudinally cut; FIG.</li><li>FIG. 7 shows the longitudinal section along the line VII VII in FIG. 8, the locking bolt being in a pre-locking position;</li><li>FIG. 8 is the view in the direction of the arrow VIII in FIG. 7 without housing, housing cover and circuit board and without steering spindle;</li><li>FIG. 9 is a perspective view corresponding to the view of FIG. 8, the locking bolt being longitudinally cut; FIG.</li><li>FIG. 10 is a plan view of the face of the control member provided with a spiral groove; FIG. </li><li>FIG. 11 is a sectional view taken along the line XI-XI in FIG.</li></ul>

The illustrated device for locking the steering spindle 1 of a motor vehicle against rotation has a one-piece locking bolt 2 which cooperates with groove-shaped locking recesses 3 of a locking sleeve 4 fastened on the steering spindle 1. The steering spindle 1 and the blocking sleeve 4 are enclosed by a non-reproduced casing tube with a passage opening for the blocking boom 2.

The locking pin 2 has a rectangular cross-section and is axially displaceable in a cross-section of a housing 6 corresponding to a channel 5. The two wider side faces 7, 8 of the channel 5 extend in each case in a plane which is perpendicular to the common longitudinal axis 9 of the steering spindle 1 and the jacket tube coaxial therewith. On the side remote from the channel 5, the housing 6 is provided with a mounting opening 11, which is closed by a cover 10, and is fastened to the jacket tube.

1, 2, 3, in which, with its end 12 facing the steering spindle 1, it engages in a locking recess 3 of the locking sleeve 4 so that the steering spindle 1 can no longer be turned, and the locking bolt 2, 4, 5, 6, in which the locking bolt 2 engages with the end 12 no locking recess 3 of the locking sleeve 4 and releases the steering spindle 1 so that it can be rotated.

For the axial displacement of the locking pin 2 into the release position and in the opposite direction into the blocking position, a control member 14 which can be rotated back and forth by means of an electric motor 13 with a reversible rotary direction is used. The control member 14 is adjacent to that of the steering spindle on the side of the locking bolt 2 facing the housing cover 10 1, and is rotatably mounted in the housing 6 on a cylindrical projection 16 of the housing 6 which engages in a central bearing bore 17 of the control element 14 and extends perpendicularly to the two wider side faces 7, 8 of the channel which guides the locking pin 2 5 of the housing 6.

The control member 14 is provided with a spiral groove 18 which winds around the bearing bore 17 of the control member 14 and into which a pin 19 projecting laterally from the locking bolt 2 engages so that the locking pin 2, when the control member 14 is rotated, Is axially displaced in one direction or in the other direction radially relative to the axis of rotation of the control member 14 defined by the housing projection 16 in the one or the other direction.

The cylindrical pin 19 is mounted in an axially displaceable manner in a cylindrical bore 20, which is provided in the remote spindle 15 of the locking pin 2, and is loaded in the direction of the control member 14 by a screw compression spring 21 arranged in the bore 20. The control member 14 has an oblique surface 24 which is co-operating with the pin 19 as described below and which rises from the bottom 22 of the spiral groove 18 to the plane surface 23 of the control member 14 facing the blocking pin 2 and extends along the spiral groove 18 Begins at a point 25, described below, of the bottom 22 of the spiral groove 18. The locking bolt 2 is loaded by a screw compression spring 26 in the direction of the steering spindle 1, which on the one hand is supported on a shoulder 27 of the locking bolt 2 and on the other hand on a shoulder 28 of the housing 6

The control element 14 is designed as a circular disk with a peripheral toothing 29 into which engages a drive screw 30 which is fastened on the output shaft 31 of the electric motor 13. The electric motor 13 is arranged in the housing 6 next to the locking pin 2 so that its output shaft 31 extends parallel To the two narrower side surfaces 32, 33 of the locking bolt 2

The control member 14 is axially fixed on the cylindrical projection 16 of the housing 6 by a cylindrical projection 34 of larger diameter of the housing cover 10 and is provided on the end side facing away from the locking pin 2 with a projecting spiral rib 35 which winds around the bearing bore 17 of the control member 14 and With which a spring-loaded two-armed pivoted lever 37 pivotable in the housing 6 about an axis 36 parallel to the housing projection 16 cooperates to provide an electrical switch 38 both in the rotational position of the control member 14 corresponding to the blocking position of the locking pin 2, and in the release position of the locking bolt 2 Rotational position of the control member 14. A further electrical switch 39 is actuated by a pin-shaped lateral projection 40 of the locking bolt 2 when the locking bolt 2 assumes its release position. The two electrical switches 38, 39 are arranged on a printed circuit board 41 which is fastened in the housing 6 and is parallel to the housing cover 10.

The mode of operation of the described device for locking the steering spindle 1 against rotation is particularly clear from FIGS. 3, 6, 9.

In order to displace the one-part locking bolt 2 axially from the blocking position according to FIG. 3 in the direction of the arrow A into the release position according to FIG. 6, the electric motor 13 is switched on so that its output shaft 31 moves the control member 14 in the direction of the arrow via the drive screw 30 B, and the pin 19 of the locking bolt 2 moves in the spiral groove 18 of the control member 14 closer and closer to the axis of rotation (bearing hole 17) of the control member 14.

3, the electric motor 13 is switched on, so that its output shaft 31, via the drive screw 30, moves the control element 14 in the direction of the arrow. In the embodiment shown in FIG D rotates, and the pin 19 of the locking bolt 2 moves further and further away from the axis of rotation (bearing hole 17) of the control member 14 in the spiral groove 18 of the control member 14.

When, during the rotation of the control element 14 in the direction of the arrow D, the blocking bolt 2 or the spindle-side end 12 of the control spindle 14 is not opposed by a locking recess 3 of the steering spindle 1 or of the locking sleeve 4, the locking bolt 2 or the end 12, The pin 19 of the locking bolt 2 is located with its free end. As a result, the locking pin 2, as shown in FIG At the point 25 of the bottom 22 of the spiral groove 18 of the control element 14. When further rotating the control element 14 in the direction of the arrow D, the pin 19 slides with its free end along the oblique surface 24 of the control element 14 on the plane surface 23 of the control element 14 facing the blocking bolt 2 in the direction of the action of the screw compression spring 21 into the bore 20 of the locking bolt 2 and to leave the spiral groove 18 of the control member 14 so that the control member 14 can be further rotated in the direction of the arrow D into the position corresponding to the blocking position of the locking pin 2 as shown in FIG.

9, the one-piece locking bolt 2 reaches the locking position according to FIG. 3 under the action of its screw compression spring 26 when the steering spindle 1 with the locking sleeve 4 moves from the position according to FIG. 9 into the position according to FIG In which a locking recess 3 of the locking sleeve 4 is aligned with the adjacent end 12 of the locking pin 2. In the embodiment shown in FIG. The pin 19 of the locking bolt 2 slides with its free end on the flat surface 23 of the control member 14 in order finally to be advanced out of the bore 20 of the locking pin 2 into engagement with the spiral groove 18 of the control member 14 by means of its screw compression spring 21.