FR2787538A1 - Shock absorbing structure for railway vehicles has longitudinal reinforcement connected to longitudinal plates and extending in shock direction - Google Patents

Abstract

Shock absorbing structure is of elongated shape in shock direction (Oz) and comprises longitudinal plates (2). Longitudinal reinforcement (15) is connected to longitudinal plates and extends in shock direction. Reinforcement has width increasing from its first (16) to second (18) longitudinal ends. End (16) is towards end of structure (17), forming deformation starting end. Second end (18) is near second end (19) of structure.

Description

The invention relates to a shock absorption structure by

  mechanical deformation, said structure being elongated according to

  an impact direction and comprising longitudinal plates.

  The invention applies in particular to railway vehicles.

  The specifications of vehicles transporting people and in particular railroads require the presence of such shock absorbing structures capable, thanks to a programmed deformation, of absorbing energy in the event of an accident to preserve human lives.

and equipment.

  The requirements for energy absorption capacity of these shock absorbing structures are increasingly high then

  that we simultaneously seek to reduce the masses of railroad vehicles

  res. Such shock absorption structures must therefore be

  light and resist static forces. In addition, during a shock, they must

  wind is deformed, crashing into an "accordion", essentially according to the

  direction of impact without shifting transversely or twisting.

  Document EP-B-621 416 describes such a structure

  shock absorption which is made up of longitu-

  dinales welded together. The cross section of the structure, sensi-

  constantly constant along the direction of impact, includes a rectangle whose angles are connected by diagonals which form an X inside the rectangle. ' In the event of an impact, the deformation will initiate randomly at

  One of the two ends of the structure which can lead to instability

  lity of the deformation and therefore a relatively low energy absorption.

  In addition, it can be seen that, during a shock, the long effort

  gitudinal supported in the direction of impact by such a structure reaches a threshold peak value of a peak, from which the crushing of the structure begins, then the longitudinal force collapses so that the energy absorbed by the structure shock absorption, equal to the area of the

  force / deformation curve, is relatively low.

  It is therefore desirable to be able to limit the decrease in

  the longitudinal force supported by the structure during its deformation.

  However, this longitudinal force, corresponding to the acceleration supported by the passengers of the vehicle, must not be too high, so that the corresponding acceleration is bearable by the passengers of the vehicle.

  The object of the invention is to solve these problems by providing

  sant a shock absorption structure which can be obtained by modifying

  simple and economical creation of an existing shock absorption structure

  aunt, whose deformation in the direction of impact is better controlled,

  stability during crushing and energy absorption capacity ac-

  floods, of relatively low weight, and which causes accelerations

  portable by passengers of the vehicle on which it is mounted.

  To this end, the subject of the invention is a structure for shock absorption by mechanical deformation, said structure being of elongated shape in a direction of impact and comprising longitudinal plates, characterized in that the structure further comprises at

  minus a longitudinal reinforcement which is attached to one of said plates lon-

  longitudinal and extending along the direction of impact, said or each longitudinal reinforcement having a generally increasing width from a first longitudinal end of the reinforcement towards a second longitudinal end of the reinforcement, in that the first longitudinal end of said or each reinforcement is oriented towards a first longitudinal end of the structure forming a primer end, erosion of the deformation of the

  structure, and in that the second longitudinal end of said or cha-

  that reinforcement is located in the vicinity of the second end of the structure.

  According to particular embodiments, the structure

  shock absorbing may include one or more of the characteristics

  following, taken in isolation or in all technical combinations

  only possible: - the first longitudinal end of said or each reinforcement is spaced from the longitudinal initiating end of the deformation of the structure; - Said or each longitudinal reinforcement extends over most of the length of the structure; - Said or each longitudinal reinforcement is of strictly increasing width over its length from its first longitudinal end; - Said or each longitudinal reinforcement comprises at least one longitudinal section of substantially constant width; - Said longitudinal plates comprise at least one pair of opposite external plates which are situated respectively on opposite sides of the structure and which extend symmetrically with respect to a respective median plane parallel to the direction of impact, and identical longitudinal reinforcements are reported on the two plates of

  said pair of opposite plates, said longitudinal reinforcements being available

  s symmetrically with respect to said median plane; - Said longitudinal plates comprise at least two pairs of opposite outer plates, the plates of each of said

  pairs being located on opposite sides of the structure and extending sy-

  metrically relative to a respective midplane parallel to the direction

  shock, the plates of one of said pairs of outer plates oppo-

  sées being orthogonal to the plates of the other pair of opposite outer plates, the structure having a cross section of substantially rectangular outer contour; - The structure comprises at least one oblique longitudinal reinforcement lining which connects the plates of at least one pair of opposite external plates by extending in an inclined manner relative to normal to the respective median plane;

  - the structure comprises at least two longitudinal linings-

  the reinforcing obliques which connect the plates of at least one pair of said opposite outer plates extending in an inclined manner with respect to IZ Tm V to normal to the respective median plane, and said oblique reinforcing linings substantially form an X in section transverse; - the structure is substantially symmetrical with respect to an axis

  of symmetry parallel to the direction of impact.

  The invention will be better understood on reading the description

  which follows, given solely by way of example, and made with reference to the accompanying drawings, in which: - Figure 1 is a schematic perspective view of a shock absorbing structure according to the invention, and - Figure 2 is a schematic perspective view illustrating

  a variant of the structure of FIG. 1.

  Figure 1 shows a shock absorption structure

1 for rail vehicle.

  A direct orthogonal coordinate system Oxyz is shown in this figure.

  gure i for easier description.

  Structure 1 has a generally elongated shape along the Oz axis

  which corresponds to the direction of shock.

  The structure 1 comprises longitudinal metal plates

  welded together along weld beads extending parallel to each other

also to the direction of shock Oz.

  Structure 1 has a general cross section which pre-

  substantially feels like a rectangle inside which diag-

nales form an X.

  Thus, the structure 1 comprises two pairs of longitu-

  external dinals 2 and 3 which form the rectangular external contour of

cross section.

  The plates 2 of the first pair are rectangular and

  identical, parallel to each other and parallel to the Oz axis, and extend sy-

  metrically along structure 1 with respect to a passing midplane

  by the mean line L of structure 1 and parallel to the Oyz plane.

  e- 1W-1U The mean line L is the straight line passing through the set of

  centers of inertia G of successive cross sections of structure 1.

  A single center of inertia G is shown in Figure 1.

  The plates 3 of the second pair are rectangular, pa-

  parallel to each other and to the Oz axis, and extend symmetrically along the structure 1 with respect to another median plane passing through the middle line

L and parallel to the Oxz plane.

  The lower plate 3 (in FIG. 1) has a width according to

  the Ox axis slightly lower than that of the upper plate 3. The pla-

  ques 3 have the same length (along the Oz axis).

  Plates 2 are orthogonal to plates 3 and are

  die to them along their longitudinal edges.

  Thus, the upper longitudinal edges (in FIG. 1) 6 of the

  plates 2 are welded, parallel to line L, on plate 3 above

  lower, a short distance from the longitudinal edges 7 of the upper plate 3

  better. Likewise, the lower longitudinal edges 8 of the plates 2 are welded, parallel to the line L, on the longitudinal edges 7 of the

bottom plate 3.

  The shock absorbing structure 1 also comprises oblique longitudinal plates 10, 11 and 12 of reinforcement, which extend inside the structure 1 in an inclined manner relative to the plates 2 and 3, to form the X of the cross section of the structure 1 which is centered on the middle line L. Thus, the plates 10 to 12 extend in an inclined manner relative to the normals at the two median planes passing through the

  mean line L and respectively parallel to the Oxz and Oyz planes.

  The oblique plates 11 and 12 are each of significant width

  roughly equal to half the width of the oblique plate 10.

  The plates 10 and 11 are connected by folding respectively to the lower longitudinal edges 8 of the plates 2 left and right (on the

figure 1).

  The oblique plates 10 and 1 1 and respectively 10 and 12 are

  substantially welded along the middle line L of structure 1.

  The plates 11 and 12 are substantially coplanar so that these plates extend symmetrically to the plate 10 with respect to the median plane passing through the mean line L and parallel to the Oyz plane. The upper longitudinal edge 13 of the oblique plate 10 is welded to the right plate 2, slightly below the longitudinal edge

  upper 6 of this plate 2 right.

  The upper longitudinal edge 14 of the oblique plate 12 is welded to the left plate 2, slightly below the longitudinal edge

  upper 6 of this plate 2 left.

  According to the invention, the structure 1 further comprises two reinforcements

  longitudinal forts 15, of which only one is visible in FIG. 1, and which have been

  each reported on an outer plate 2.

  These longitudinal reinforcements 15 are identical and made up

  each by a metal plate in the shape of an elongated isosceles trapezoid.

  These reinforcements 15 are fixed by welding to the plates 2 with their heights oriented parallel to the direction of impact Oz. The two longitudinal reinforcements 15 are symmetrical to each other with respect to the

  average line L and the shock absorption structure 1 is thus globa-

  slightly symmetrical with respect to the mean line L. For each reinforcement 15, a first longitudinal end 16, corresponding to the small base of the trapezoid, is located at a distance from a first longitudinal end 17 of the shock absorbing structure 1. This distance can, for example, correspond to 20% of the length of

  the structure 1. The other longitudinal end 18 of the reinforcement 15, corresponds to

  dant at the large base of the trapezoid, is located in the vicinity of the second longitudinal end 19 of the structure 1, preferably at a distance

  less than 1% of the length of the structure 1.

  The reinforcement 15 extends over the essentials, preferably at least

  %, of the length of the structure 1.

  Thus, the first two ends 16 of the reinforcements 15 are oriented towards the same end 17 of the structure 1 and the width (along the axis Oy) of these reinforcements 15 increases along these reinforcements 15 from

their first ends 16.

  The maximum width of the reinforcements 15 is less than the width

(along the axis Oy) of the plates 2.

  The shock absorption structure is intended to be integrated

  rigged at the ends of the chassis of a railway vehicle to absorb a shock occurring in the direction Oz by crushing of the structure 1

in this direction.

  It is noted that in the event of such a shock on the structure 1 thus integrated, the deformation by crushing begins at the first end 17 of the structure 1 and propagates progressively towards its second end 19. This programmed deformation is obtained thanks to the shape and position of the longitudinal reinforcements 15 which give the structure 1 increasing longitudinal rigidity from the first end 17.

  Thanks to the presence of the diagonal plates 10, 11, 12 available

  sés substantially symmetrically with respect to the average line L, the deformation occurs mainly by dynamic plastic buckling

  along the Oz axis and the structure 1 remains stable without chasing transverse-

  along the Ox and Oy axis or twist.

  In addition, the longitudinal dynamic force supported by the struc-

  ture grows gradually, but very slightly, during crushing

  of structure 1. Thus, a large energy absorption is obtained in con-

  serving acceptable effort levels for vehicle passengers.

  This acceptable growth or even a slight decrease

  sance can be obtained by varying the number and dimensions of

reinforcements 15.

  In addition, the invention makes it possible to modify existing shock-absorbing structures by only attaching the longitudinal reinforcements 15 to them. This simple and economical modification only slightly increases the weight of existing shock absorption structures. According to a variant not shown, the length of the longitudinal reinforcements 15 could be substantially equal to that of the shock absorbing structure 1. According to the variant of FIG. 2, each longitudinal reinforcement 15 comprises from its first end 16 a first section 20 along which the reinforcement 15 is of strictly increasing width, then a second section 21 ending at the second end 18 and along which the width of the reinforcement 15 is substantially constant. This variant

  allows better adjustment of the absorption capacity of structure 1 to the

specifications of specifications.

  According to another variant, not shown, triangular transverse reinforcing members can be arranged inside the

  structure 1 and welded to the oblique plates 10, 11 and 12 and to the plates ex-

  tiors 2 and 3. This makes it possible to stage the crushing of structure 1.

  Of course, the invention can be applied to other vehicles

than rail vehicles.

Claims (10)

  1. Structure (1) for shock absorption by meteorological deformation   canic, said structure being elongated in a direction of impact (Oz) and comprising longitudinal plates, characterized in that the structure further comprises at least one longitudinal reinforcement (15) which is attached to one of said longitudinal plates (2) and which extends along the direction of impact, said or each longitudinal reinforcement (15) having a   generally increasing width from a first longitudi-   nale (16) of the reinforcement towards a second longitudinal end (18) of the reinforcement   strong, in that the first longitudinal end (16) of said or each reinforcement is oriented towards a first longitudinal end (17) of the structure (1) forming an initiating end of the deformation of the structure, and in that the second longitudinal end (18) of said or each reinforcement is located in the vicinity of the second end (19) of the structure (1).   2. Structure according to claim 1, characterized in that the first longitudinal end (16) of said or each reinforcement is separated   of the longitudinal end (17) for initiating the deformation of the struc-   ture. 3. Structure according to claim 1 or 2, characterized in that said or each longitudinal reinforcement (15) extends over most of the length of the structure (1).   4. Structure according to any one of claims 1 to 3,   characterized in that said or each longitudinal reinforcement (15) is of wide   gor strictly increasing along its length from its first end longitudinal (16).   5. Structure according to claim 1 to 3, characterized in that said or each longitudinal reinforcement (15) comprises at least one section   longitudinal (21) of substantially constant width.   6. Structure according to any one of claims 1 to 5,   characterized in that said longitudinal plates comprise at least one pair of opposite outer plates (2, 3) which are located respectively on opposite sides of the structure (1) and which extend   symmetrically with respect to a respective median plane parallel to the direction   tion of shock, and in that identical longitudinal reinforcements (15) are attached to the two plates (2) of said pair of opposite plates, said longitudinal reinforcements (15) being arranged symmetrically with respect to wearing said median plane.   7. Structure according to claim 6, characterized in that   said longitudinal plates comprise at least two pairs of plates   ques external opposite (2, 3), the plates of each of said pairs   being located on opposite sides of the structure and extending symmetrically   relative to a respective median plane parallel to the direction of   shock, the plates (2) of one of said pairs of outer plates oppo-   sées being orthogonal to the plates (3) of the other pair of external plates   opposite, the structure having a cross section of contour ex-   substantially rectangular inside.   8. Structure according to claim 6 or 7, characterized in that it comprises at least one oblique longitudinal lining (10, 11, 12)   reinforcement which connects the plates (2) of at least one pair of external plates   opposite laughs, extending at an angle to the nor- maie to the respective median plane.   9. Structure according to claim 8, characterized in that it comprises at least two oblique longitudinal linings (10, 11,   12) of reinforcement 'which connect the plates (2) of at least one pair of said plates   opposite external ones extending in an inclined manner with respect to   normal to the respective median plane, and in that said linings obli-   reinforcing ques (10, 11, 12) substantially form an X in cross section dirty:   10. Structure according to any one of claims 1 to 9,   characterized in that it is substantially symmetrical with respect to an axis   of symmetry (L) parallel to the direction of impact.