STEERING LOCK FOR A MOTOR VEHICLE

Abstract

The invention relates to a motorized steering column lock for a motor vehicle, comprising a bolt (30) that is able to move between a column locking position and a column unlocking position, and also an electric motor (10) for driving the bolt between the unlocking position and the locking position, characterized in that the bolt is mounted so as to approach the steering column in a direction parallel to the steering column.

Description

The invention relates to steering-column locks of the electrically motorized type.

Many constructions of steering-column locks are known. First, steering-column locks have been proposed comprising a motor and a gearwheel which drives a locking bolt via a cam or a gradient associated with the gearwheel, wherein the gearwheel rotates about a shaft which is parallel to the output shaft of the electric motor, or else in which the gearwheel rotates about a shaft which is perpendicular to the output shaft of the electric motor.

The bolt then travels in a sliding manner closer to the steering column under the action of a cam or of a gradient formed by the gearwheel until it engages a peripheral ring gear of the steering column.

The known electrically motorized steering-column locks also have too great a space requirement for a certain arrangements with considerable space constraints, such as arrangements in a bottom portion of the steering column, for example close to or incorporated into a motorized assistance module for assisting the rotation of the steering column.

The object of the invention is to alleviate the drawbacks of the known electrically motorized steering locks and notably to propose a steering-column lock configuration that can be housed in a restricted space in the bottom portion of the steering column.

This object is achieved according to the invention by virtue of a motorized steering-column lock for a motor vehicle comprising a bolt that can move between a locked position and an unlocked position of the column and an electric motor for driving the bolt between the unlocked position and the locked position, characterized in that the bolt is mounted so as to approach the steering column in a direction parallel to the steering column.

Other features, objects and advantages of the invention will become apparent on reading the following detailed description made with reference to the appended figures in which:

FIG. 1 is an overview of a steering lock according to a preferred embodiment of the invention;

FIG. 2 is an exploded view in perspective from above of this same steering lock;

FIG. 3 is an exploded view in perspective from below of this same steering lock;

FIG. 4 is a partial view of this same steering lock in the unlocked and immobilized position of this same steering lock;

FIG. 5 the position is a partial view of this same steering lock in the locked and released position of this same steering lock;

FIG. 6 is a partial view with no shuttle and from below of this same steering lock in the unlocked and immobilized position;

FIG. 7 is a partial view with no shuttle and from below of this same steering lock in the locked and released position;

FIG. 8 is a partial view with no shuttle and from above of this same steering lock in the unlocked position;

FIG. 9 represents an assembly consisting of a steering column and a module for assisting the pivoting of a steering column which module includes a steering lock according to one embodiment of the invention.

The steering lock shown in FIG. 1 comprises an electric motor 10 furnished with an output shaft forming a worm 15, a gearwheel 20 engaged in the worm 15, a bolt 13 mounted so as to slide, these various elements being placed in a housing 40.

The gearwheel 20 is mounted so as to rotate about a shaft 21 which extends perpendicularly to the output shaft of the motor 10 so that the output shaft of the motor is indistinguishable in the geometric plane of the gearwheel.

The gearwheel 20 has a first face 22, turned toward a steering column not shown, which is furnished with a cam 23 in a disk portion which interacts in thrust with the bolt. For this purpose, the bolt 30 has, in addition to a main bar 31, a lateral appendage 35 capable of being interposed on the path of the cam 23 when the latter pivots with the gearwheel 20 in order to come closer to an outer ring gear of the steering column. The bolt is advantageously returned to the locked position by a spring.

This lateral appendage has the shape of an S of which the top curve forms a bearing wall for the cam 23 of the gearwheel and of which the bottom curve receives within it an element for retention in the unlocked position as will be described below.

Therefore, when the gearwheel 20 is rotated, the bolt 30 travels slidingly in a plane parallel to the main plane of the gearwheel. Since the gearwheel 20 is in this instance oriented such that it is in a plane parallel to the steering column, the bolt therefore itself travels parallel to the main direction of the steering column.

In order to be locked when the bolt is in the final position, the steering column has a lateral appendage interacting with the bolt, in this instance a ring gear 80 of which the teeth have between them interstices accommodating the bolt in its extended locked position.

In another embodiment, the lateral appendage may be a simple finger of radial orientation relative to the main direction of the steering column, or else a transverse plate furnished with a series of through-holes and capable of accommodating the bolt in multiple angular positions of the steering column.

The gearwheel 20 has, on its face oriented away from the column, a track in an arc of a circle 24 formed here in the form of a built-up element out of the face of the gearwheel 20.

The track 24 extends over three-quarters of the angular extent about the shaft of the gearwheel 20 and has, at each of its ends, a sliding bevel which adjoins the main plane of the face 22.

The track 24 interacts with a shuttle 60 mounted so as to move slidingly sideways to the main plane of the gearwheel and more specifically in this instance mounted so as to slide on the rotation shaft of the gearwheel.

This shuttle has a radial extension 62 in the direction of the bolt 30 and, via a finger 64 oriented sideways to the main plane of the gearwheel 20, extends inside the bolt 30 in a selective manner as will be explained below.

Specifically, the shuttle 60 rests against the track 22 via a slide 65 formed in relief on the shuttle face turned toward the gearwheel and the shuttle is thus kept resting against the track 24 sideways to the gearwheel 20 by a spring, not shown. Due to this, the shuttle sustains a movement sideways to the gearwheel while the latter pivots on itself when the slide 65 rises or falls from the built-up track 24. During this movement, the shuttle 60 is held against a pivoting about the rotation shaft of the gearwheel by interaction of a finger, not shown, made of the same material as the steering-lock housing and engaged in an orifice passing through the shuttle 60.

As shown in FIG. 8, the built-up track 24 is placed such that, when the bolt is in the locked position of the steering column, the shuttle is separated from the gearwheel, that is to say that the slide 65 is resting on the track 24 and the overlocking finger of the shuttle does not then engage the bolt. Conversely, the built-up track is placed such that the shuttle 60 is brought closer to the gearwheel, that is to say that the slide 65 is out of the track 24 when the bolt is in the unlocked position and that the shuttle then secures, by the overlocking finger, the bolt in the unlocked position. Accordingly, the S shape formed by the bolt has its proximal curve to the main body of the bolt facing the overlocking finger when the bolt is in the unlocked position, thus allowing the overlocking finger to penetrate the proximal curve of the S. The finger is then positioned as an obstacle on the return path of the bolt and more specifically of the proximal curve of the S, thus preventing an inadvertent return of the bolt to its locked position.

As an alternative, the built-up element presented by the track 24 increases during the travel of the track such that a first end of the arc of a circle described by the track is close to a main plane of the gearwheel and another end of the arc of a circle described by the track 24 is further away sideways from the main plane of the gearwheel 20.

By virtue of the present orientation of the bolt moving parallel to the steering column, whether it be driven by a gearwheel thus positioned or positioned differently for example perpendicularly to the steering column, it gives an overall space requirement of the steering-column lock that is particularly low and notably in the direction radial to the steering column.

This low space requirement is particularly notable in the case in which the gearwheel is oriented parallel to the steering column, but a gain in space requirement is already easily obtained by such an orientation of the movement of the bolt even when the gearwheel is perpendicular to the steering column.

Moreover, although a bolt sliding parallel to the steering column is preferred in terms of space requirement, a gain in space requirement is already obtained when the portion of the bolt that engages the steering column approaches the steering column in a direction substantially parallel to the column, whether the bolt slides or rotates, in which case a movement of the substantially tangential end of the bolt therefore parallel with the column or a lateral appendage of the latter provides a considerable advantage in terms of space requirement of the steering lock.

In the present example, the housing 50 of the steering lock is advantageously arranged in the form of a liquor bowl, that is to say as an extension in the main direction of the steering column and in a cross section in the shape of a bean, that is to say included between two transverse limits in an arc of a circle of respectively lesser and greater radius.

The steering-column lock then closely follows a cylinder contour of the steering column so as to occupy only a small space radial to the column. Such a space requirement is particularly advantageous in the present case in which the steering-column lock is an element constituting a module of motorized assistance to the rotation of the steering column. Incorporating the steering lock in a module of motorized assistance to the pivoting of the steering column provides an advantage in terms of safety since the steering lock is then in a particularly low portion of the column, at a particularly great distance from the instrument panel where it is the predilection of a thief to operate and in a particularly inaccessible portion of the vehicle.

In the present case and as shown in FIG. 9, the motorized assistance module comprises an assisting motor 70 which is oriented such that its output shaft 75 extends parallel to the steering column. The output shaft 75 of the motor 70 has peripheral gear teeth in which a ring gear 80 surrounding the steering column meshes in order to rotate the latter. The ring gear 80 is advantageously the ring gear in which the bolt 30 engages such that only one ring gear is used for the two functions of driving and immobilization, further reducing the space requirement for the implementation of the described assisting module.

Advantageously, the steering lock and the assisting motor 70 are placed radially opposite to the steering column such that the bolt 30 and the output shaft of the assisting motor do not interfere. The motorized assistance module advantageously comprises one and the same electronic unit for controlling the pivoting assistance and controlling the immobilization of the column, which ensures that no assistance control is applied to the assisting motor when the steering lock is in the locked position.

Because the steering-column lock is a portion of the module for motorized assistance of the rotation of the steering column, the control unit that is common to the motorized assistance and to the locking of the column is advantageously fitted with a control logic using a slight rotational movement of the steering column when it simultaneously commands a force to operate the unlocking of the bolt. Thus, by this slight movement, any frictional retention is removed between the bolt and the steering column, for example between the bolt and a lateral edge of a tooth of the ring gear 80 and the bolt travels slidingly in a reliable manner with each switching on of the vehicle.

The control unit is advantageously implemented in the form of an electronic circuit placed in a common housing 90 of the assisting motor 70 and of the steering lock. The electronic circuit is advantageously positioned outside the housing 50 of the steering lock. In addition to the implementation of controlling the steering lock via this control unit, in this instance notably takes account of the positioning of the bolt that is indicated to it by the receipt of output signals from sensors of positioning of the bolt that are placed in the steering lock. These two sensors, referenced 35 and 36, are in this instance magnetic sensors activated by a magnet placed on the bolt but which, as a variant, can be mechanical sensors activated by a boss of the bolt. As an alternative, they may be sensors associated with the gearwheel, the immobilizing shuttle or any other member of the steering lock. The signals delivered by these sensors are advantageously directly read by the control unit.

Claims

1. A motorized steering-column lock for a motor vehicle comprising: a bolt configured to move between a locked position and an unlocked position of the column; andan electric motor for driving the bolt between the unlocked position and the locked position, wherein the bolt is mounted so as to approach the steering column in a direction parallel to the steering column.

2. The steering-column lock as claimed in claim 1, wherein the electric motor has an output shaft and a worm placed on the output shaft and a gearwheel in which the worm of the motor output shaft is engaged, the gearwheel being oriented in a plane parallel to the steering column.

3. The steering-column lock as claimed in claim 1, wherein the motor is oriented so that its output shaft is in a plane parallel to the steering column.

4. The steering-column lock as claimed in claim 1, wherein the bolt is mounted so as to slide in the steering lock in a sliding direction parallel to the steering column.

5. The steering-column lock as claimed in claim 1, further comprising an element that can move between a position of immobilizing the bolt in the unlocked position and a position of releasing the bolt.

6. The steering-column lock as claimed in claim 5, wherein the electric motor has an output shaft and a worm placed on the output shaft and a gearwheel in which the worm of the output shaft of the motor is engaged and the movable element for immobilizing the bolt is resting on a portion of the gearwheel which pushes the movable immobilizing element away from the bolt when the gearwheel is rotated.

7. The steering-column lock as claimed in claim 6, wherein the gearwheel has a track in an arc of a circle progressively moving away laterally from the gearwheel and the movable immobilizing element is resting against the track so as to move closer and further away when the gearwheel is rotated.

8. A module for assisting the rotation of a steering column comprising an assisting motor applying a pivoting force to the steering column, wherein the module comprises a steering lock as claimed in claim 1.

9. An assembly comprising a steering column of a motor vehicle and a steering lock as claimed in claim 1.

10. A combined assembly of a steering column of a motor vehicle and a module for assisting the rotation of the steering column as claimed in claim 8, wherein the steering column comprises a peripheral ring gear in which the bolt is engaged in the locked position and which peripheral ring gear receives a steering-column pivoting force delivered by the assisting motor.