FR2793206A1 - RETRACTABLE STEERING COLUMN FOR A VEHICLE AND TOLERANCE PART THEREFOR - Google Patents

Abstract

A retractable steering column for a vehicle includes a first inner tube (1) which can be telescopically retracted, in the event of a vehicle crash, relative to a second outer tube (2). A third tolerance part (3) is arranged between the inner and outer tubes in order to take up the tolerance between them and in order to provide a force of resistance to telescopic retraction between the two tubes. The tolerance part (3) has at least two blades (4) connected by an intermediate part (4A) provided to press on an inner end of the inner tube (1). Preferably, the tubes (1, 2) are substantially triangular and there are three blades (4), one for each face of the triangular profile. Tabs (5) are preferably provided at the end of each blade (4) for positioning and energy absorption. The blades (4) can be provided with ridges and / or protrusions for energy absorption purposes.

Description

This invention relates to a retractable steering column for a

vehicle and to a piece of

tolerance for it.

  According to one aspect of the present invention, there is provided a retractable steering column for a vehicle, the steering column having a first elongated part which can be inserted into a second elongated part which is an outer tube of the steering column, a third part which can be positioned between said first and second parts in order to make up a tolerance between them and to provide a force of resistance to telescopic retraction between said first and second parts; characterized in that said third part has at least two blades connected by an intermediate part intended to press on one end of said first part which is to be inserted in said second part and in that the internal surface of the outer tube and the external surface of the first part have non-circular profiles in order to prevent a

relative rotation between them.

  According to another aspect of the present invention, there is provided a tolerance part of a retractable steering column for a vehicle, said tolerance part being able to be positioned between a first elongated part and a second elongated part which is an outer tube of the steering column, said first elongated part being insertable into said second part and said tolerance part serving to make up the tolerance between said first and second parts and to provide a force of resistance to telescopic retraction between said first and second parts; characterized in that said tolerance part has at least two blades connected by an intermediate part intended to press on one end of the first part which is to be inserted in said second part, and in that the internal surface of the outer tube and the surface external of the first part have non-circular profiles in order to prevent relative rotation between them. Said first part can be a tube

  inside the steering column.

  The non-circular profile can be substantially triangular. The intermediate part of the third tolerance part can be generally profiled in order to correspond to the section of the end of the first part, with the two blades which extend along the respective faces of the non-circular profile of the first part. In the case where the profile of the first part is substantially triangular, the third tolerance part may have three blades connected by the intermediate part, each blade being designed, during use, to extend against a respective outer face of the

first part.

  Before installing the third tolerance part on the end of the first part, the blades can be spread outwards from the intermediate part so that, when positioning the first part in the second part, the blades are forced to flex at their links with the intermediate part in order to reach the condition

  installed inside the second part.

  A free end of at least one blade may be provided with a tab, extending outwards from the first part when the third part is supported on it, the or each tab acting initially as a stop in order to limit the entry of the first part into the second part and then, during the retraction of the steering column, provide an increased load by straightening the or each leg when the first

  part is forced more in the second part.

  At least one of the blades can be provided with ridges and / or projections in order to increase the friction load between the first and second parts when they are assembled with the third tolerance part. The ridges / protrusions can be oriented axially with respect to the blades, transversely to the

  blades and / or inclined with respect to these axes.

  The invention also extends to a vehicle comprising a retractable steering column according to the

first aspect of the invention.

  For a better understanding of the invention and in order to show how it can be implemented, reference will now be made, by way of example, to the appended drawings, in which: FIG. 1 is a schematic perspective view of a retractable steering column for a vehicle incorporating a plate or tolerance part, FIG. 1A is a perspective view of the plate or tolerance part incorporated in the steering column of FIG. 1, FIG. 2 is a view in schematic perspective of a variant form of the tolerance part, illustrated in the condition that it reaches after insertion in the second part, FIG. 3 is a schematic perspective view of the tolerance part of FIG. 2 in its delivery state before insertion in the second part, Figures 4, 5 and 6 are perspective views illustrating other possible modifications of the tolerance part, Figure 7 is a graph i illustrating a typical retraction load of the steering column provided with a legless tolerance piece (Figures 2 to 6), and Figure 8 is a graph similar to that of Figure 7 but showing a typical load when a part of tolerance using legs like this is

  illustrated in Figures 1 and 1A is used.

  Figure 1 shows a part of a steering column assembly comprising a first part in the form of a substantially triangular inner tube 1 which is inserted into an outer tube 2 which has a corresponding substantially triangular internal profile. A third part, in the form of a so-called tolerance plate 3 is inserted into the tube 2 outside the tube 1 and is designed to make up for the tolerance between the two tubes and to provide a force of resistance to telescopic retraction. between the two tubes, thus eliminating the

  play and preload the connection between the two tubes.

  The tolerance plate 3 is better represented in FIG. 1A and comprises three blades 4 connected by an intermediate base part 4A which is designed to press on the internal end of the inner tube 1 which must be

  inserted into the outer tube 2.

  The free ends of each blade 4 are, in the form shown in FIGS. 1 and 1A, each provided with a tab extending outwards 5. These optional tabs 5 on the tolerance plate 3 act in order to abut against the end of the outer tube 2 when the plate 3 is in contact with the end of the inner tube 1 and the combination is inserted into the outer tube 2. The tabs 5 provide a visual aid in order to check whether the inner tube has been assembled to the correct length in the outer tube and if the retraction mechanism provided by the desired structure has been

  accidentally / prematurely activated.

  Figure 2 shows the shape of the plate

tolerance 3 without legs 5.

  Figure 3 shows the tolerance plate 3 in its delivery state with the faces 4 pre-folded at 60 as shown in 4B so that, in the delivery condition, a set of tolerance plates

  can easily be stacked during transport / storage.

  In addition, the tolerance plate 3 positions itself on the end of the inner tube 1 for assembly and the initial insertion force to assemble the junction is reduced, because the folds 4B act as stress elevation elements that encourage faces 4 to

  flex more towards the installed condition.

  Therefore, during assembly, the tolerance plate 3, when located on the end of the inner tube 1, uses the inner tube 1 as a form of press tool when forced into the outer tube bore 2. The retraction load of the finished assembly can be completely checked by

  recording the force to assemble the junction.

  Figures 4, 5 and 6 illustrate the fact that at least one face 4 and, in the illustrated shapes, all the faces of the tolerance plate 3 can be provided with concave and / or convex ridges of different sizes, shapes and positions , so as to finely adjust the preload force and therefore in order to control the

variation of retraction load.

  Figure 4 shows sets of convex protrusions 6A extending axially with respect to the tolerance plate 3 (and the inner tube 1), while Figure 5 shows transverse convex protrusions 6B and Figure 6 shows inclined convex protrusions 6C (the

  tilt degrees can be changed).

  As shown, the streaks are convex; however, the direction of the streaks can be concave and, of course, a combination of

  both convex and concave 6 can be used.

  Any combination of features

  as described above can be combined.

  It should therefore be noted that, in the event of a vehicle accident, there is a tendency for the two tubes 1, 2 to retract telescopically and the tolerance plate 3 provides the load intended to absorb the energy. When the legs 5 are provided, there is an increase in the load required in order to unfold the

  legs during initial retraction.

  FIG. 7 shows the load during this retraction in the case where the tabs 5 are not provided and it can be seen that an initial peak load 7 intended to generate the retraction is not very pronounced, while the level of force 8 required in order to continue retraction

remains roughly constant.

  FIG. 8 illustrates the case where the tabs 5 are provided and the initial peak load 9 intended to generate the retraction is much more significant. The level of force 10 required in order to continue the retraction again remains more or less constant. Initial charge 9 simulates

  a trigger peak load.

  It should be noted that the present construction provides two tubes of similar profiles inserted one inside the other with a tolerance plate which serves to eliminate any radial play by preloading the inner faces and

  respective outer tubes against each other.

  This preload provides the axial tripping force required to retract the tube construction into a

  steering column assembly tube.

  The tolerance plate 3 can be made of any suitable material, for example spring steel, stamped metal or plastic.

Claims (11)

  1. A retractable steering column for a vehicle, the steering column having a first elongated part (1) which can be inserted into a second elongated part (2) which is an outer tube of the steering column, a third part (3) able to be positioned between said first and second parts in order to make up for a tolerance between them and to provide a force of resistance to telescopic retraction between said first and second parts; characterized in that said third part (3) has at least two blades (4) connected by an intermediate part (4A) intended to press on one end of said first part (1) which must be inserted in said second part (2) and in that the inner surface of the outer tube (2) and the outer surface of the first part (1) have non-circular profiles in order to prevent relative rotation between them. 2. Tolerance part (3) of a retractable steering column for a vehicle, said tolerance part being able to be positioned between a first elongated part (1) and a second elongated part (2) which is an outer tube of the column steering, said first elongated part being able to be inserted into said second part and said tolerance part (3) serving to make up the tolerance between said first and second parts and to provide a force of resistance to telescopic retraction between said first and second parts ; characterized in that said tolerance part (3) has at least two blades (4) connected by an intermediate part (4A) intended to press on one end of the first part (1) which is to be inserted in said second part, and in that the inner surface of the outer tube (2) and the outer surface of the first part (1) have non-circular profiles in order to prevent a relative rotation between them.   3. Steering column or tolerance part according to claim 1 or 2, respectively, wherein said first part (1) is an inner tube of the steering column.   4. Steering column or tolerance part according to claim 1, 2 or 3, in which the profile is not   circular is substantially triangular.   5. Steering column or tolerance piece according to   any one of the preceding claims, in   which the intermediate part (4A) of the third tolerance part (3) is generally profiled in order to correspond to the cross section of the end of the first part (1), with the two blades (4) which s 'extend along the respective faces of the non-circular profile of the first part.   6. Steering column or tolerance piece according to   claims 4 and 5, wherein the part of   tolerance (3) has three blades (4) connected by the intermediate part (4A), each blade being designed, during use, to extend against an outer face   respective of the first part (1).   7. Steering column or tolerance part according to claim 1 or 2, respectively, or according to one   any of claims 3 to 6, wherein, before   to set up the third tolerance part (3) on the end of the first part (1), the blades (4) are spread outwards from the intermediate part (4A) so that, during positioning of the first part (1) in the second part (2), the blades are forced to bend at their connections with the intermediate part in order to reach the condition   installed inside said part.   8. Steering column or tolerance part according to claim 1 or 2, respectively, or according to one   any of claims 3 to 7, wherein a   free end of at least one said blade (4) is provided with a tab, extending outward from said first part (1) when said third tolerance part (3) is supported thereon, the or each tab (5) initially acting as a stop in order to limit the entry of said first part (1) into the second part (2) and then, during the retraction of the steering column, provide an increased load thanks to the straightening of the or each leg when said first part is   forced more in said second part.   9. Steering column or tolerance part according to claim 1 or 2, respectively, or according to one   any of claims 3 to 8, wherein at least   one of said blades (4) is provided with ridges and / or projections (6A, 6B, 6C) in order to increase the friction load between said first and second parts (1, 2) when they are assembled with said third part of tolerance (3) between them.   he 10. Steering column or tolerance part according to claim 9, in which the ridges and / or projections (6A, 6B, 6C) are oriented axially with respect to the blades (4), transversely to the blades and / or inclined by in relation to these axes.   11. Vehicle comprising a steering column   retractable according to any one of claims 1 to 10.