FR2787409A1 - Steering column for motor vehicle has two tubular sections sliding together and with deformable shock absorbing insert between them - Google Patents

Abstract

The steering column for a motor vehicle has two tubular sections (1,3) which can slide together and with shock dampers (5) mounted in the shaft sections. The shock damper has a section shaped like a grapnel of deformable material with a frame (6) having a folded branch (8,9) at one end (7). The end section is attached to one of the shaft sections. The other end is attached to the other shaft section.

Description

The present invention relates to a telescopic steering shaft with

  shock energy absorption especially for motor vehicle.

  More particularly, the invention relates to a steering shaft which comprises two tubular portions of shaft displaceable to slide one inside the other and between which are interposed means for absorbing energy.

  shock shock by controlling the displacement of these relative to each other.

  We have already developed in the prior art, different embodiments of these telescopic steering shafts and these different means

  shock energy absorption, to reduce the risk of injury to con-

  motor vehicle drivers and the intrusion of column sets

  steering in the passenger compartment of these vehicles, especially in the event of an accident.

  We thus interposed between the two shaft portions, means

  formable to absorb impact energy.

  These means are for example integrated into the fixing structure of

  these steering column assemblies on the rest of the vehicle structure.

  According to other embodiments, these means of absorbing energy

  shock gies are formed for example by means of deformation of one

  and / or the other of the shaft portions during their relative displacement.

  However, all these solutions present a certain number of in-

  advantages, particularly in terms of their size, of the progressiveness of

  energy absorption and its reproducibility during mass production applications.

  The object of the invention is therefore to solve these problems.

  To this end, the subject of the invention is a telescopic steering shaft for absorbing impact energy, in particular for a motor vehicle, of the type comprising two tubular portions of shaft movable to sliding, one

  in the other and between which energy absorption means are interposed

  shock absorption by controlling the displacement of these relative to each other, characterized in that the means for absorbing shock energy are housed in the shaft portions and comprise a member in the form of grapple in

  deformable material under stress, comprising a central core provided at an ex-

  end of at least one folded branch connected to the rest of the latter by an elbow portion and the end of which is associated with one of the shaft portions,

  while the other end of the soul of the grapnel-shaped organ is asso-

  ciée to the other shaft portion to absorb the impact energy when the two shaft portions move relative to each other, by deformation of the member

  in the form of a grapple by moving the elbow connecting the branch to the rest of it.

  The invention will be better understood with the aid of the description which follows.

  vre, given only by way of example and made with reference to the drawings an-

attached, on which:

  - Fig.1 shows a sectional view of a remote steering shaft-

scopic according to the invention; and

  - Fig.2 shows a perspective view of an exemplary embodiment

  tion of energy absorption means used in such a tree.

  In fact, FIG. 1 shows a telesco-

  impact absorption spike, in particular for a motor vehicle, which comprises two tubular shaft portions movable by sliding one inside the other. One of the tree portions, designated by the general reference 1, is

  an outer shaft portion and is adapted to receive the steering wheel.

  This portion of shaft then has an end of reduced section designated

  by the general reference 2 adapted to receive the steering wheel hub.

  The other portion of the tree is designated by the general reference 3 and is

  associated with the rest of the vehicle's steering mechanism.

  These tree portions include for example complementary means

  rotational coupling elements formed by complementary grooves

  res whose splines of the shaft portion 1 are designated by the reference

general 4 in this figure.

  Shock energy absorption means are interposed between these

two tree portions.

  These means are adapted to absorb the impact energy by con-

  the movement of these two shaft portions, and are in fact housed in these tubular shaft portions. These means comprise a grapple-shaped member made of deformable material under stress, designated by the general reference 5 in this figure, comprising a central core designated by the general reference 6 provided at one end with at least one folded branch connected to the rest of this by a portion of the curve and the end of which is associated with one of the

tree portions.

  In the embodiment shown, the grap-shaped organ

  pine has at its end 7, two symmetrical folded branches, designated

  by the general references 8 and 9 in this figure.

  The end of each of these branches 8 and 9, that is to say the ends

  mites 8a and 9a respectively, are associated with the shaft portion 3 by

  hook means as will be described in more detail later.

  The other end of the core 6, that is to say its end 10, is in turn associated with the shaft portion 1 and comprises for example as will be described in more detail below, means of support on the section portion

  reduced 2 of this portion of tree.

  In fact, this grapnel-shaped member 5 can be formed from two parts.

  these symmetrics arranged back to back as shown in FIG. 2.

  One of these parts, designated by the general reference 11, then comprises at one end, a folded portion designated by the general reference 12

  provided at its end with a hook-shaped portion designated by the reference

  general reference 13, allowing it to be attached to the corresponding portion of the tree

dante.

  At its other end, this part is provided with a support surface

  signed by the general reference 14 adapted to abut against the door

  tion of reduced section 2 of the corresponding shaft portion.

  In its intermediate portion, this part can include at least

  a part provided with one or more guide tabs, one of which is

  signed by the general reference 15, adapted to cooperate with corresponding axial grooves, formed at the level of a central recess 16 (Fig. 1) of a plug 17 for anchoring the hook-shaped portions of the end of the

  branches of the grapnel-shaped organ 5 on the corresponding tree portion

  dante. Indeed, this anchor plug 17, made for example of plastic, and comprising the central recess 16 which allows the passage of the core 6 of the grapnel-shaped member 5, ensures the fixing of the ends in

  hook shape of this grapnel-shaped member on the shaft portion 3.

  In addition, this anchor plug 17 may include a flange of ex-

  end designated by the general reference 18 adapted to cooperate with the axial grooves 4 formed on the internal face of the shaft portion 1 by

example to ensure its guidance.

  The absorption of shock energy during the movement of the two shaft portions relative to one another then takes place by deformation of this grapnel-shaped member by moving the elbow connecting the or each branch to the soul of

this one, along its axis.

  So for example, if we consider that during a shock the portion of ar-

  bre 1 does not move and the shaft portion 3 sinks into this portion of ar-

  bre 1, it can be seen that the end 10 of the grapnel-shaped member 5 is supported on the reduced section portion 2 of this shaft portion 1 and that the hook-shaped portions 8a and 9a of the ends of the branches 8 and 9 of this organ,

  are fixed on this portion of the shaft 3, so that during the movement of the

  relative to each other, the elbow portions connecting the branches to the core of the grapnel-shaped organ slide progressively along the axis

  of this grapnel-shaped organ, by deforming it, which makes it possible to absorb

ber shock energy.

  This is also the case if we consider that the shaft portion 3 does not move and that it is the shaft portion 1 which sinks onto this shaft portion 3. The deformation of the organ in grapple shape is then caused by a thrust of the shaft portion 1 on the end 10 of the core 6 of this grapple-shaped member 5, the hook-shaped portions 8a and 9a of the ends of the branches 8 and 9 thereof still being locked in position by the plug 17

on the tree portion 3.

  The anchor plug 17 then also ensures a guide

  dage of the soul of this grapnel-shaped member during this relative displacement

tree portions.

  It goes without saying of course that still other embodiments of

  this direction tree can be considered.

Claims (7)

  1. Telescopic steering shaft with shock absorption no-   especially for a motor vehicle, of the type comprising two tubular shaft portions (1,3) movable in sliding one inside the other and between which are interposed means for absorbing impact energy (5) by controlling the displacement of these relative to each other, characterized in that the shock energy absorption means (5) are housed in the shaft portions (1,3) and include a member in form of a grab made of deformable material under stress, comprising a central core (6) provided at one end (7) with at least one folded branch (8, 9) connected to the rest of the latter by an elbow portion and whose l end is associated with one of the shaft portions (3), while   the other end (10) of the core (6) of the grapnel-shaped member (5) is associated   ciée to the other shaft portion (1), to absorb the impact energy during displacement   cementing of the two shaft portions relative to each other, by deformation of the grapnel-shaped member (5) by moving the elbow connecting the branch to the rest of it.   2. Tree according to claim 1, characterized in that said grapnel-shaped member (5) comprises at its corresponding end (7), at least   two symmetrical folded branches (8,9).   3. Tree according to claim 1 or 2, characterized in that the end   mity of the or each folded branch (8, 9) of the grapple-shaped member (5) is provided with a hook-shaped portion (13) fixed on the corresponding shaft portion (3) by l 'via an anchor plug (17) provided with a   central recess (16) for passage of the grapnel-shaped member (5).   4. Tree according to claim 3, characterized in that the anchor plug (17) comprises an end flange (18) adapted to cooperate with axial grooves (4) formed on the internal face of the other portion tree (1).   5. Tree according to claim 3 or 4, characterized in that the grapnel-shaped member (5) comprises at least one portion provided with at least one   guide tongue (15) adapted to cooperate with an axial groove cor-   correspondent formed at the level of the central recess (16) of the plug of an- crage (17).   6. Tree according to any one of the preceding claims,   characterized in that the end (10) of the grapnel-shaped member (5) associated with the other portion of shaft (1) comprises support means (14) on a portion of reduced section (2) thereof.   7. Tree according to any one of the preceding claims,   characterized in that the grapnel-shaped member (5) is made up of two parts   symmetrical arranged back to back (11).