FR3052422B1 - BODY STRUCTURE OF A RAIL VEHICLE AND METHOD FOR ASSEMBLING SUCH A STRUCTURE OF THE BODY - Google Patents

Abstract

Rail vehicle body structure (1), comprising a frame (5, 6), at least one panel (10), and a plurality of bolts (15A, 15B) securing the panel to the frame, each bolt having a rod ( 46A, 46B) and maintaining a surface (36) of the panel facing a surface (30) of the frame along an axis (D) of the rod. The body structure further comprises friction sheets (20A, 20B). For each of the bolts, at least one of the friction sheets is compressed by the bolt between the surface of the panel and the surface of the frame. The surface of the panel has a sliding resistance with respect to the surface of the frame in a longitudinal direction (L). perpendicular to the axis (D), said friction sheet being adapted, with constant tightening of the bolt, to increase the sliding resistance.

Description

Rail vehicle body structure and method of assembling such a body structure

The present invention relates to a railway vehicle body structure, the body structure comprising a frame, at least one panel, and a plurality of bolts securing the panel to the frame, each bolt of the plurality having a rod and holding a surface of the panel vis-à-vis a surface of the frame along an axis of the rod. The invention also relates to a method of assembling such a body structure.

To achieve a body structure of a rail vehicle, such as a car, or a wagon, it is known to assemble panels, for example side, on a frame, forming for example the frame of the future floor and on a pavilion forming the future roof of the vehicle. Such panels are usually fixed by welding, riveting or bolting.

In the case of bolting, to obtain a correct fixing of the panel, the bolts are generally of diameter M20. But, because of the length of the chassis (typically 23 meters in modern trains), and the number of bolts per meter to obtain a correct assembly, the total mass of the bolts is important, of the order of 350 kg. However, it is not conceivable to switch from M20 bolts to M16 bolts, because the number of bolts should then be increased, which would not significantly reduce the total mass. Moreover, by increasing the prestressing by choosing bolts of diameter M16 more resistant, one would increase the cost of the fasteners, and would complicate the implementation of the clamping.

Riveting is attractive, especially in single-sided areas (referred to as blind riveting), but structural rivet diameters do not exceed 12 mm and rivets have low shear strength. Blind crimping bolts with a diameter of 12 to 16 mm fitted are then used because the prestressing of these elements is too low to make them work in non-slip mode, as is the case with a non-blind bolt. The adjusted assembly presents difficulties of realization related to the respect of the necessary tolerances: precision of the machines, counter-drilling. This last operation has the disadvantage of producing chips incompatible with the assembly of pre-lined or already painted panels. This results in additional costs related to the protection of the panels to obtain a correct quality.

In order to improve the sliding resistance of bolted or riveted joints, it is also known to produce surface treatments (painting, sanding) which prove to be expensive to implement.

Welding is interesting to lighten the structure and provides continuous bonds distributing the constraints and therefore very resistant. However, it does not allow the same flexibility as bolting or riveting. For example, the assembly of body structures in several materials is more difficult to achieve by welding. In addition, welding requires expensive special skills in personnel training.

An object of the invention is to solve all or part of the problems mentioned above, that is to say in particular to provide a body structure in which the panel is properly fixed on the frame, with a weight saving total, the fixing remaining simple to achieve and a cost comparable or lower than the existing costs. For this purpose, the subject of the invention is a body structure of the type described above, in which: the body structure further comprises friction sheets, for each of said plurality of bolts, at least one of the friction sheets is compressed by the bolt between the surface of the panel and the surface of the frame, and - the surface of the panel having a sliding resistance with respect to the surface of the frame in a longitudinal direction perpendicular to the axis, said sheet of friction is adapted, with constant tightening of the bolt, to increase the resistance to sliding.

According to particular embodiments, the body structure comprises one or more of the following features, taken in any technically possible combination: each friction sheet is disposed respectively around one of said plurality of bolts; for each of said plurality of bolts, the friction sheet has a generally washer-like shape substantially centered on the axis of the rod; for each of said plurality of bolts: the rod has a rod diameter, and the washer has an internal diameter less than or equal to the rod diameter increased by 3 mm, preferably increased by 1.5 mm; each bolt of said plurality comprises a nut, and: the nut has an external nut diameter, the frame locally has a frame thickness along the axis of the rod, between the nut and the washer, and the washer has an outer diameter less than or equal to the sum of the external nut diameter and twice the thickness; for each bolt of said plurality: the rod comprises a head having a support diameter, the panel locally has a thickness along the axis of the rod, between the head and the washer, and the washer has a outer diameter less than or equal to the sum of the support diameter and twice the thickness; for each of said plurality of bolts: the chassis comprises, at least locally, a transverse groove intended to allow transverse positioning of the panel with respect to the chassis, the chassis having two lips located on either side of the groove, each of the lips defining a portion of said chassis surface, and - the friction sheet comprises a first portion and a second portion sandwiched respectively between the two lips and the panel surface; for each of said plurality of bolts: the friction sheet comprises at least one portion adhered to the panel surface, and the bonded portion extends only between the two lips in a direction perpendicular to the transverse direction, so that that the bonded portion lies outside the first portion and the second portion of the friction sheet; for each of said plurality of bolts, the friction sheet comprises at least one suitable mark intended to allow an angular orientation of the friction sheet with respect to the panel around the axis of the rod, the angular orientation being intended ensuring that the bonded portion on the friction sheet facing the panel surface is oriented angularly about the axis of the shaft so as to extend only between said two lips; and - the friction sheet comprises at least two pins adapted and adapted to allow said angular orientation of the friction sheet, the two marks being diametrically opposite with respect to the axis of the rod, the two marks preferably including, respectively, at least one notch located in a radially outer edge of the friction sheet. The invention also relates to a method of assembling a rail vehicle body structure, the method comprising at least the following steps: - fixing at least one panel on a chassis using a plurality bolts, each bolt of the plurality having a rod and holding a surface of the panel opposite a surface of the frame along an axis of the rod, - providing friction sheets, and - for each of the bolts of said plurality, compressing at least one of the friction sheets between the surface of the panel and the surface of the frame compressed by the bolt, the surface of the panel having a sliding resistance with respect to the surface of the frame in a longitudinal direction perpendicular to the axis, the shear sliding resistance being increased by the constant-tightening friction sheet of the bolt. The invention will be better understood on reading the description which will follow, given solely by way of example, and with reference to the appended drawings, in which: FIG. 1 is a general schematic view of a structure of FIG. 2 is a sectional view along a vertical plane of a detail of the body structure shown in FIG. 1; FIG. 3 is an exploded view of the frame and the panel represented on FIGS. FIGS. 1 and 2; FIG. 4 is a front view of one of the friction sheets shown in FIGS. 2 and 3, and FIG. 5 is a detail of FIG. 2 showing dimensions of one of the bolts and of one of the friction sheets shown in FIG.

Referring to Figure 1, there is described a body structure 1 according to the invention intended to be part of a rail vehicle not shown.

The body structure 1 comprises a lower body 2 and an upper roof 3, respectively comprising frames 5, 6. The body structure 1 also comprises two panels 10 forming two side walls 12A, 12B. The assembly of the panels 10 on the rocker 2 and the upper roof 3 forms a "tube" to be subsequently closed at both ends by transverse end walls (not shown).

Referring to Figures 2 and 3, the mounting of one of the panels 10 on the frame 5 located in the rocker 2. The mounting of the panels 10 on the frame 6 in the roof is similar and will not be described .

The body structure 1 comprises a plurality of bolts 15A, 15B for fixing the panel 10 to the frame 5, and a plurality of friction sheets 20A, 20B respectively compressed by the bolts 15A, 15B between the frame and the panel. The body structure 1 comprises for example other panels (not shown) similar to the panel 10, the panels being advantageously fixed on the frame 5 successively in a longitudinal direction L of the frame.

The longitudinal direction L is for example the running direction of the future railway vehicle and is horizontal when the body structure 1 is oriented as it is intended to be in this vehicle.

The frame 5 is for example an aluminum metal frame made from extruded profiles known in themselves. The chassis 6 is for example of structure similar to that of the chassis 5.

According to a variant not shown, this frame is made of mechanically welded steel.

In Figures 2 and 3, only a portion of the frame 5 is shown. The part shown corresponds for example to a longitudinal portion of a lateral edge of the future floor of the vehicle.

On the side of the panel 10, the frame 5 comprises a face 22 (Figure 3) defining for example two grooves 24A, 24B oriented longitudinally and superimposed in a direction V perpendicular to the longitudinal direction and an axis D of the bolt 15A.

The direction V is for example substantially vertical.

The grooves 24A, 24B are adapted to respectively receive nuts 26A, 26B of the bolts 15A, 15B by locking them in rotation about the axis D (Figures 2 and 5).

The grooves 24A, 24B being similar to each other, only the groove 24A will be described in detail below.

The groove 24A is advantageously cruciform in section perpendicular to the longitudinal direction L (that is to say in the plane of Figures 2 and 5) so as to match the shape of the bolt 15A. The groove 24A defines two longitudinal lips 28 arranged opposite one another in the direction V. The groove 24A is adapted to allow sliding of the nut 26A in longitudinal translation as long as the bolt 15A is not tight.

The lips 28 partially close the groove 24A and prevent the nut 26A out of the groove 24A along the axis D. The lips 28 define a surface 30 (Figure 5), preferably flat, and intended to be in contact with the sheet friction 20A.

In the example shown, because of the presence of the groove 24A, the surface 30 of the frame 5 is in two parts respectively corresponding to the lower and upper lips 28. Still in the example shown, the surface 30 corresponding to the lower lip 28 of the groove 24B is separated by a groove 32 of the surface 30 corresponding to the upper lip 28 defined by the groove 24A.

The groove 32 is for example frustoconical section and facilitates positioning along the axis V of the panel 10 before tightening.

The lips 28 have for example a thickness E1 (Figure 5) along the axis D. The thickness E1 is also the distance between the nut 26A of the friction sheet 20A when the bolt 15A is tightened. The thickness E1 is for example between 5 mm and 15 mm, and is advantageously about 10 mm.

The panel 10 also advantageously has a honeycomb structure comprising a main wall 34 defining, at each bolt 15A, 15B, a surface 36 intended to be in contact with the friction sheets 20A, 20B respectively, a skin 38 located at the opposite the frame 5 relative to the main wall 34, and reinforcing elements 40 extending between the skin and the main wall.

The panel 10 advantageously extends from the represented portion of the frame 5 to the frame 6.

In the example, the skin 38 defines an opening 42, for example oblong, giving access to two bores 44A, 44B formed in the main wall 34 for the bolts 15A, 15B.

The bolts 15A, 15B are for example of the M16 type. In addition to the nuts 26A, 26B, the bolts 15A, 15B further comprise respectively rods 46A, 46B oriented parallel to the axis D, and washers 48A, 48B on the opposite side to the nuts.

In the example shown, the rods 46A, 46B are screws respectively having heads 50A, 50B.

According to a variant not shown, the rods 46A, 46B are studs. The heads 50A, 50B are then for example nuts.

A single plate 52 is further interposed between the washers 48A, 48B and the main wall 34 of the panel 10.

The bolts 15A, 15B being similar to each other, only the bolt 15A will be described in detail below. The nut 26A has an outer diameter DEE about the axis D. Still with respect to the axis D, the head 50A of the rod 46A has a support diameter DA and is separated from the friction sheet 20A by a distance E2 along the axis D.

The support diameter DA is for example between 20 mm and 30 mm, and is advantageously about 25 mm.

The distance E2 is the sum of the thicknesses of the main wall 34, the plate 52 and the washer 48A along the axis D.

The distance E2 is for example between 10 mm and 20 mm, and is advantageously about 12 mm.

The outer diameter DEE is for example between 40 mm and 50 mm, and is advantageously about 45 mm.

The rod 46A has a DT rod diameter.

The stem diameter DT is preferably about 16 mm.

In the example shown, each friction sheet 20A, 20B is assigned to one of the bolts 15A, 15B, in that it is compressed by this bolt and not by another of the plurality.

According to variants not shown, the same friction sheet is compressed by at least two bolts of the plurality.

According to another variant not shown, a plurality of separate friction sheets are arranged near a same bolt of the plurality, so as to be compressed by this bolt only.

Since the friction sheets 20A, 20B are similar to each other, only the friction sheet 20A will be described in detail below.

As seen in Figure 4, the friction sheet 20A has a generally washer-like shape centered on the axis D of the bolt 15A.

The friction sheet 20A has a small thickness, preferably less than 0.5 mm, for example about 0.16 mm. It consists for example of a metal sheet, two layers of phosphorus nickel fixed on the faces of the metal sheet, and ceramic particles or diamonds located in and on said layers.

Said layers and the particles create a roughness typically between 10 μm and 50 μm.

The friction sheet 20A is advantageously bonded to the surface 36 of the panel 10 to facilitate the assembly of the body structure 1.

The friction sheet 20A has an inner diameter DI advantageously less than or equal to the diameter of the rod DT plus 3 mm, preferably less than or equal to DT plus 1.5 mm. DI internal diameter complies with the ISO standards in force for bores for the passage of fastening screws.

The friction sheet 20A has an outer diameter DE advantageously less than or equal to a value DMAX1 equal to the sum of the outer diameter of the nut DE and twice the thickness E1.

The outer diameter DE is also advantageously less than or equal to a value DMAX2 equal to the sum of the support diameter DA and twice the thickness E2.

As can be seen in FIG. 4, the friction sheet 20A comprises two pins 54, advantageously diametrically opposite with respect to the axis D, making it possible to orient the friction sheet angularly about the axis D with respect to the panel 10. markers 54 are further adapted to indicate to an operator two bonding areas 56 in which he can place one or more points of glue 58.

The pins 54 have for example a notch shape made on a radially outer edge 57 of the friction sheet 20A.

The zones 56 are defined as the points of an internal face 60 of the friction sheet 20A situated at a distance X from a line L1 parallel to the longitudinal direction L and passing through the axis D, the distance X being less than half the stem diameter DT. Thus, by arranging the glue in the gluing zones 56 and then by orienting the marks 54 in the longitudinal direction L when the friction sheet 20A is glued on the face 36 of the panel 10, the operator is assured that the glued areas will not be sandwiched between the frame 5 and the panel 10, which avoids subsequent creep phenomena troublesome for controlling the prestress in the assembly.

Friction sheet 20A includes a first portion 62 located above areas 56 in FIG. 4, and a second portion 64 located below.

The first portion 62 and second portion 64 are free of glue and are sandwiched between the lips 28 and the panel 10. The assembly of the body structure 1 will now be described. The assembly comprises a step of fixing the panel 10 on the frame 5 by means of the bolts 15A, 15B.

The friction sheets 20A, 20B are previously glued on the face 36 of the main wall 34 of the panel 10. The friction sheets 20A, 20B are advantageously glued in the bonding zones 56 identified by the marks 54.

Then, the friction sheets 20A, 20B are respectively disposed around the holes 44A, 44B, the pins 54 being aligned longitudinally, so that the bonded areas 58 are located between the lips 28 in the direction V.

Then, the rods 46A, 46B of the bolts are inserted into the holes 44A, 44B. The rods 46A and 46B are screwed into the nuts 26A, 26B previously inserted into the grooves 24A, 24B.

The grooves 24A, 24B lock the nuts 26A, 26B in rotation around the rods 46A, 46B.

The heads 50A, 50B are then screwed with a tool (not shown) via the window 42 until the desired tightening. This clamping is performed at a minimum prestressing level to obtain a sufficient pressure at the interface which anchors the friction sheets 20A, 20B on the parts in contact.

The friction sheets 20A, 20B are then compressed between the surfaces 30 of the frame 5 and the surface 36 of the panel 10.

Each friction sheet 20A, 20B locally contributes, respectively to the bolts 15A, 15B, to frictionally increase the resistance to sliding or shear in the plane defined by the directions L and V.

It is thus possible to reduce the diameter, the quality class or the number of bolts 15A, 15B used.

By passing for example bolts M20 to M16, it alleviates the body structure 1 of about 70 kg. In addition, the M16 bolts are less expensive than the M20 bolts, so the cost of the body structure is also reduced.

With the features described above, the panel 10 is properly fixed on the frame 5, with a weight gain of about 20% of the total mass of the bolts. Fastening is simple to perform and lower cost because M16 bolts are cheaper than M20 bolts and the assembly does not require surface preparation.

In addition, the dimensional criteria listed above make it possible to optimize the positioning of each of the friction sheets 20A, 20B with respect to the panel 10 or the frame 5. The criteria relating to the internal diameter DI make it possible to center the washer on the bolts. The criteria relating to the outer diameter DE make it possible to give the washer a maximum diameter both smaller than the values DMAX1 and DMAX2 beyond which the material of the friction sheets 20A, 20B does not contribute significantly to the increase of the resistance. to slip.

Finally, the marks 54 make it possible to orient the friction sheets 20A, 20B at the moment when they are placed around the bores 44A, 44B. The fact that each friction sheet is glued avoids their displacement or loss during the assembly of the body structure 1.

Claims (10)

1Car body structure (1), the body structure (1) comprising a frame (5, 6), at least one panel (10), and a plurality of bolts (15A, 15B) securing the panel (10); ) on the frame (5, 6), each bolt (15A, 15B) of the plurality having a shank (46A, 46B) and holding a surface (36) of the panel (10) facing a surface (30) of the frame (5, 6) along an axis (D) of the rod (46A, 46B), characterized in that: - the body structure (1) further comprises friction sheets (20A, 20B) for each of the plurality of bolts (15A, 15B), at least one of the friction sheets (20A, 20B) is compressed by the bolt (15A, 15B) between the surface (36) of the panel (10) and the surface (30) of the frame (5, 6), and - the surface (36) of the panel (10) having a sliding resistance with respect to the surface (30) of the frame (5, 6) in a longitudinal direction (L ) perpendicular to the axis (D), said sheet of friction (20A, 20B) is adapted, with constant tightening of the bolt (15A, 15B), to increase the sliding resistance, and - for each of the bolts (15A, 15B) of said plurality, the friction sheet (20A, 20B) has a general shape of washer substantially centered on the axis (D) of the rod (46A, 46B). 2, - body structure (1) according to claim 1, wherein each friction sheet (20A, 20B) is disposed respectively around one of the bolts (15A, 15B) of said plurality. 3, - body structure (1) according to claim 1 or 2, wherein for each of the bolts (15A, 15B) of said plurality: - the rod (46A, 46B) has a rod diameter (DT), and the washer has an internal diameter (ID) less than or equal to the stem diameter (DT) increased by 3 mm, preferably increased by 1.5 mm. 4, - body structure (1) according to any one of claims 1 to 3, wherein each of the bolts (15A, 15B) of said plurality comprises a nut (26A, 26B), and wherein: - the nut (26A, 26B) has an outer diameter of nut (DEE), - the frame locally has a frame thickness (E1) along the axis (D) of the rod (46A, 46B), between the nut (26A , 26B) and the washer, and - the washer has an outer diameter (DE) less than or equal to the sum of the outer diameter of the nut (DEE) and twice the thickness (E1). 5. - body structure (1) according to any one of claims 1 to 4, wherein for each of the bolts (15A, 15B) of said plurality: - the rod (46A, 46B) comprises a head (50A, 50B) having a support diameter (DA), - the panel (10) locally has a thickness (E2) along the axis (D) of the rod (46A, 46B), between the head (50A, 50B) and the washer, and the washer has an outer diameter (DE) less than or equal to the sum of the support diameter (DA) and twice the thickness (E2). 6. - body structure (1) according to any one of claims 1 to 5, wherein for each of the bolts (15A, 15B) of said plurality: - the frame (5, 6) comprises, at least locally, a transverse groove (24A, 24B) for transversely positioning the panel (10) with respect to the frame (5, 6), the frame (5, 6) having two lips (28A, 28B) located on both sides another of the groove (24A, 24B), each of the lips (28A, 28B) defining a portion of said frame surface (30) (5, 6), and - the friction sheet (20A, 20B) comprises a first portion (62) and a second portion (64) respectively sandwiched between the two lips (28A, 28B) and the panel surface (36). 7. Body structure (1) according to claim 6, wherein for each of the plurality of bolts (15A, 15B): - the friction sheet (20A, 20B) comprises at least one bonded portion (58) on the surface (36) of panel (10), and - the bonded portion (58) extends only between the two lips (28A, 28B) in a direction (V) perpendicular to the transverse direction (T), so that the bonded portion (58) lies outside the first portion (62) and the second portion (64) of the friction sheet (20A, 20B). 8. Body structure (1) according to claim 7, wherein for each of the plurality of bolts (15A, 15B) of said plurality, the friction sheet (20A, 20B) comprises at least one mark (54) adapted and intended to allow angular orientation of the friction sheet (20A, 20B) relative to the panel (10) about the axis (D) of the rod (46A, 46B), the angular orientation being intended to ensure that the portion bonded (58) on the friction sheet (20A, 20B) facing the panel surface (30) is angularly oriented about the axis (D) of the shank (46A, 46B) so to extend only between said two lips (28A, 28B). Rail body structure (1) according to claim 8, wherein the friction sheet (20A, 20B) comprises at least two pins (54) adapted and adapted to allow said angular orientation of the friction sheet ( 20A, 20B), the two marks (54) being diametrically opposite with respect to the axis (D) of the rod (46A, 46B), the two marks (54) comprising, respectively, preferably at least one notch located in a radially outer edge of the friction sheet (20A, 20B). 10. - Method of assembling a body structure (1) of a railway vehicle, the method comprising at least the following steps: - fixing at least one panel (10) on a frame (5, 6) to the using a plurality of bolts (15A, 15B), each bolt of the plurality having a shank (46A, 46B) and holding a surface (36) of the panel (10) facing a surface ( 30) of the frame (5, 6) along an axis (D) of the rod (46A, 46B), - supply of friction sheets (20A, 20B) respectively having, for each bolt (15A, 15B) of said plurality , a general form of washer substantially centered on the axis (D) of the rod (46A, 46B), and - for each of the bolts (15A, 15B) of said plurality, compressing at least one of the friction sheets ( 20A, 20B) between the surface (36) of the panel (10) and the surface (30) of the frame (5, 6) compressed by the bolt (15A, 15B), the surface (36) of the panel having a sliding resistance with respect to the surface (30) of the frame (5, 6) in a longitudinal direction (L) perpendicular to the axis (D), the shear sliding resistance being increased by the friction sheet (20A, 20B) to constant tightening of the bolt (15A, 15B).