Carriage for driving a vehicle steering system allowing a displacement of a cover part identical to the displacement of a movable tube during a depth setting and during an accident

Abstract

A drive carriage of a vehicle steering system positioned between a movable tube and a drive member, having an attachment zone intended to cooperate with the movable tube, the attachment zone making a fixation of the movable tube on the drive carriage when a force exerted on the attachment zone is below a first predetermined threshold and a movement of the movable tube relative to the drive carriage when the force exerted on the attachment zone exceeds the first predetermined threshold, the drive carriage comprises a coupling zone intended to cooperate with a cover part making the fixation of the cover part on the drive carriage when a force exerted on the coupling zone is below a second predetermined threshold and a movement of the cover part relative to the drive carriage when the force exerted on the second coupling zone exceeds the second predetermined threshold.

Claims

1. A drive carriage of a vehicle steering system positioned between a movable tube of a steering column and a drive member, the drive carriage comprising an attachment zone intended to cooperate with the movable tube, the attachment zone making a fixation of the movable tube on the drive carriage when a force exerted on the attachment zone is below a first predetermined threshold and a movement of the movable tube relative to the drive carriage when the force exerted on the attachment zone exceeds the first predetermined threshold, wherein the drive carriage comprises a coupling zone intended to cooperate with a cover part, the coupling zone making a fixation of the cover part on the drive carriage when a force exerted on the coupling zone is below a second predetermined threshold and a movement of the cover part relative to the drive carriage when the force exerted on the second coupling zone exceeds the second predetermined threshold.

2. The drive carriage according to claim 1, wherein the first predetermined threshold is substantially equal to the second predetermined threshold.

3. The drive carriage according to claim 1, wherein the second predetermined threshold has a value comprised between 5N and 50N.

4. The drive carriage according to claim 1, wherein the coupling zone makes the fixation of the cover part on the drive carriage by means of at least one retaining element which is breakable when the force exerted on the coupling zone is substantially equal to the second predetermined threshold.

5. The drive carriage according to claim 1, in which the coupling zone makes the fixation of the cover part on the drive carriage by means of a friction force.

6. The drive carriage according to claim 5, wherein the friction force has a value substantially equal to the second predetermined threshold.

7. The drive carriage according to claim 5, wherein the coupling zone comprises at least one protrusion and a slide rail cooperating with the at least one protrusion.

8. A column of a vehicle steering system comprising a cover part, a fixed tube, and a movable tube which is driven in translation by a drive mechanism, the drive mechanism comprising a drive carriage according to claim 1.

9. The column of a vehicle steering system comprising a cover part, a fixed tube, and a movable tube which is driven in translation by a drive mechanism, the drive mechanism comprising a drive carriage according to claim 7, wherein the slide rail is formed in the cover part.

10. The column of a vehicle steering system comprising a cover part, a fixed tube, and a movable tube which is driven in translation by a drive mechanism, the drive mechanism comprising a drive carriage according to claim 7, wherein the slide rail is provided with at least one assembly element intended to fix said slide rail on the cover part.

Description

(1) The invention will be better understood from the description below, which relates to several embodiments according to the present invention, given by way of non-limiting examples and explained with reference to the appended schematic drawings, in which:

(2) FIG. 1 is a representation of a steering column of a vehicle according to the state of the art;

(3) FIG. 2 is a top view representation of a first embodiment of a steering column according to the invention;

(4) FIG. 3 is a top view representation of the first embodiment of a steering column according to the invention;

(5) FIG. 4 is a top view representation of a second embodiment of a steering column according to the invention;

(6) FIG. 5 is a top view representation of the second embodiment of a steering column according to the invention after a vehicle accident;

(7) FIG. 6 is a top view representation of a third embodiment of a steering column according to the invention;

(8) FIG. 7 is a top view representation of the third embodiment of a steering column according to the invention after a vehicle accident.

(9) In the different embodiments described below, the identical elements have an identical numeral reference.

(10) A steering column 1 as illustrated in FIGS. 1 to 7, comprises a movable tube 2, supporting a steering wheel, which slides concentrically in a fixed tube. The depth setting is carried out by inserting the movable tube 2 into the fixed tube along an elongation axis X of the steering column 1. Furthermore, the movable tube 2 is driven in translation by a drive mechanism 4 comprising an electric motor 5, a worm screw 6 and a drive member 7. During the depth setting, the electric motor 5, fixed relative to the frame 3 of the vehicle, drives in rotation the worm screw 6 which carries the drive member 7. The drive member 7 then performs a translational movement along an elongation axis of the worm screw 6, identical to the translational movement of the movable tube 2.

(11) The movable tube 2 is fixed to the drive member 7 by means of a drive carriage 8, 8′, 8″, 8′″ comprising an attachment zone 9 which allows a fixation of the movable tube 2 on the drive carriage 8, 8′, 8″, 8′″ when a force exerted on the attachment zone 9 is below a predetermined threshold and a movement of the movable tube 2 relative to the drive carriage 8, 8′, 8″, 8′″ when the force exerted on the attachment zone 9 exceeds the predetermined threshold. The drive carriage 8, 8′, 8″, 8′″ is fixed on the drive member 7.

(12) The steering column 1 also comprises a cover part 11′, 11″, 11′″. The cover part 11′, 11″, 11′″ is an empty shell which at least partially envelops the movable tube 2.

(13) The cover part 11′, 11″, 11′″ is fixed to the movable tube 2 by means of a first fixing point produced near the steering wheel by means of a fixing leg 10 on the movable tube 2.

(14) The cover part 11′, 11″, 11′″ is fixed to the movable tube 2 by means of a second fixing point produced at level of the drive mechanism 4, and more precisely at the drive carriage 8′, 8″, 8′″.

(15) A first embodiment of the drive carriage 8′ is illustrated in FIGS. 2 and 3. The drive carriage 8′ according to the first embodiment has a coupling zone 12′ comprising a protrusion 13′ cooperating with a slide rail 14′.

(16) The protrusion 13′ is an elongation extending along a plane substantially parallel to the plane in which the cover part 11′ extends at the level of said elongation. The protrusion 13′ comprises a clamping element 15′. For example, the clamping element 15′ is a clamping screw. The clamping element 15′ is inserted into the slide rail 14′. The clamping element 15′ fixes the slide rail 14′ to the drive carriage 8′ by means of a friction force. The value of said friction force is equal to a second predetermined threshold.

(17) The slide rail 14′ is formed in the cover part 11′, that is to say that the slide rail 14′ is inseparable from the cover part 11′ without degrading thereof. The slide rail 14′ extends along the elongation axis X of the steering column 1. The slide rail 14′ has a through slot 16′ into which the clamping element 15′ is transversely introduced.

(18) During the mounting of the cover part 11′ on the steering column 1, the clamping element 15′ is inserted at a first end A of the slide rail 14′.

(19) During a depth setting of the steering column 1, a force exerted on the coupling zone is below the second predetermined threshold. Thus, the friction force exerted between the clamping element 15′ and the slide rail 14′ allows the fixation, that is to say a common movement, of the slide rail 14′ and the clamping element 15′.

(20) During a vehicle accident, the driver directly or indirectly exerts a force on the coupling zone 12′ below the second predetermined threshold. In this situation, the friction force exerted between the clamping element 15′ and the slide rail 14′ is not sufficient to hold the fixation of the slide rail 14′ and the clamping element 15′. The clamping element 15′ will remain secured to the drive carriage 8′ and therefore to the frame 3 of the vehicle, while the slide rail 14′ will remain secured to the cover part 11′ movable relative to the frame of the vehicle 3. The clamping element 15′ will therefore slide in the slide rail 14′ so as to pass from the first end A of the slide rail 14′ to a second end B of the slide rail 14′.

(21) A second embodiment of the drive carriage 8″ is illustrated in FIGS. 4 and 5. The drive carriage 8″ according to the second embodiment has a coupling zone 12″ comprising two protrusions 13″ cooperating with a slide rail 14″.

(22) Each protrusion 13″ has a jaw shape. Each protrusion 13″ surrounds an edge 16″ of the slide rail 14″. Each protrusion 13″ fixes the slide rail 14″ to the drive carriage 8″ by means of a friction force. The value of said friction force is equal to a second predetermined threshold.

(23) The slide rail 14″ is attached to the cover part 11″, that is to say that the slide rail 14″ can be separated from the cover part 11″ without degrading thereof. The slide rail 14″ is fixed to the cover part 11″ by means of an assembly element not represented. The slide rail 14″ extends along the elongation axis X of the steering column 1. The slide rail 14″ has two edges 16″ on which the protrusions 13″ are fixed. The edges 16″ are not in contact with the cover part 11″.

(24) During the mounting of the cover part 11″ on the steering column 1, the protrusions are positioned at a first end A of the slide rail 14″.

(25) During the depth setting of the steering column 1, a force exerted on the coupling zone is below the second predetermined threshold. Thus, the friction force exerted between the protrusions 13″ and the edges 16″ of the slide rail 14″ allows a fixation, that is to say a common movement, of the slide rail 14″ and the protrusions 13″.

(26) During a vehicle accident, the driver directly or indirectly exerts a force on the coupling zone 12″ below the second predetermined threshold. In this situation, the friction force exerted between the protrusions 13″ and the slide rail 14″ is not sufficient to hold the fixation of the slide rail 14″ and the protrusions 13″. The protrusions 13″ will remain secured to the drive carriage 8″ and therefore to the frame 3 of the vehicle, while the slide rail 14″ will remain secured to the cover part 11″ movable relative to the frame of the vehicle 3. The protrusions 13″ will therefore slide in the slide rail 14″ so as to pass from the first end A of the slide rail 14″ to a second end B of the slide rail 14″ as illustrated in FIG. 5.

(27) A third embodiment of the drive carriage 8′″ is illustrated in FIGS. 6 and 7. The drive carriage 8′″ according to the third embodiment has a coupling zone 12′″ comprising two protrusions 13′″ each cooperating with a slide rail 14′″.

(28) Each protrusion 13′″ has an elongation. Each elongation is introduced into a slide rail 14′″. Each elongation fixes the slide rail 14′″ to the drive carriage 8′″ by means of a friction force. The value of said friction force is equal to a second predetermined threshold.

(29) The slide rails 14′″ are fixed on either side of a sliding part which is attached to the cover part 11′″, that is to say that the sliding part is separable from the cover part 11′″ without degrading thereof. The sliding part is fixed to the cover part 11′″ by means of an assembly element not represented. The slide rails 14′″ extend along the elongation axis X of the steering column 1. Each slide rail 14′″ has a U shape 20′″ into which an elongation is introduced.

(30) During the mounting of the cover part 11′″ on the steering column 1, the protrusions 13′″ are positioned at a first end A of the slide rail 14′″.

(31) During the depth setting of the steering column 1, a force exerted on the coupling zone is below the second predetermined threshold. Thus, the friction force exerted between the protrusions 13′″ and the slide rails 14′″ allows a fixation, that is to say a common movement, of the slide rails 14′″ and the protrusions 13′″.

(32) During a vehicle accident, the driver directly or indirectly exerts a force on the coupling zone 12′″ below the second predetermined threshold. In this situation, the friction force exerted between the protrusions 13′″ and the slide rails 14′″ is not sufficient to hold the fixation of the slide rails 14′″ and the protrusions 13′″. The protrusions 13′″ will remain secured to the drive carriage 8′″ and therefore to the frame 3 of the vehicle, while the slide rails 14′″ will remain secured to the cover part 11′″ movable relative to the vehicle frame 3. The protrusions 13′″ will therefore slide in the slide rails 14′″ so as to pass from the first end A of the slide rails 14′″ to a second end B of the slide rails 14′″ as illustrated in FIG. 7.

(33) Each of the embodiments described above can advantageously also comprise a retaining element, not represented, which is breakable when the force exerted on the coupling zone is substantially equal to the second predetermined threshold.

(34) Of course, the invention is not limited to the embodiments described and represented in the appended figures. Modifications remain possible, in particular from the point of view of the constitution of the various elements or by substitution of technical equivalents, without thereby departing from the scope of protection of the invention.