Abstract:
A railway vehicle bogie made of composite material which includes at least one elongated rigid support secured in a chassis made of composite material. The support is adapted to removably receive fasteners for mounting functional elements of the bogie at a plurality of locations along the length of the support. The process includes disposing the elongated rigid support in a mold before the bogie chassis is cast.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a bogie for railway vehicle and to a process for manufacturing such a bogie. 
     2. Brief Discussion of the Related Art 
     It is known to produce a railway vehicle bogie in the form of massive parts made of steel or of welded structures. These massive parts and welded structures are rigid and heavy. In particular, they be must be equipped with suspension and vibration-damping systems. 
     European Patent Application 0 031 008 discloses a railway vehicle bogie comprising H-shaped cross-pieces made of composite material. These cross-pieces do not allow the assembly of accessory or safety elements such as a motor, a braking system or a control system. 
     In the case of a bogie made of composite material, it may be envisaged, for fastening the sub-systems mentioned hereinabove, generically called “functional elements” of the bogie, to use metallic inserts fixed with respect to the bogie. Such inserts must be positioned in the bogie as a function of its future use or of the functional elements that it has to support. In other words, no adaptation of the bogie to the functional elements that it supports can be envisaged after these inserts have been positioned. This results in a complex management of the process of concept and manufacture of the bogies of which the structure is fixed as far as the subsequent fixation of functional elements is concerned, from the beginning of manufacture thereof. This lack of modularity is detrimental from the economical, and also from the technical standpoint, as it is detrimental to the interchangeability of the structures of the bogies. 
     It is an object of the present invention to overcome these drawbacks by proposing a bogie made of composite material and a process of manufacturing such a bogie which make it possible to attain a satisfactory modularity for fixing the functional elements of the bogie. 
     SUMMARY OF THE INVENTION 
     To that end, the invention relates to a railway vehicle bogie made of composite material, characterized in that it comprises at least one elongated rigid support secured in a structure made of composite material, this support being adapted to removably receive means for fastening functional elements of the bogie, at a plurality of locations distributed over its length. 
     Thanks to the invention, the functional elements of the bogie may be fixed at different spots, which makes it possible to use the modular nature of the bogie by adapting the configuration of these functional elements when designing and finally assembling the bogie, and even when subsequently adding a functional element. The invention also makes it possible to reduce the time for development of a new bogie, concerning the positioniong of the functional elements, while this aspect generally takes a long time in view of the dimensions of these elements. 
     According to a first advantageous aspect of the invention, the support is formed by a hollow rail inside which at least one retaining member provided with at least one means for cooperation with a member for fixing and/or supporting a functional element of the bogie, is adapted to move. This retaining member may be constituted by a slide block provided with at least one tapping for receiving a locking screw. The displacement of the slide block inside the rail allows a fine adjustment of the position of a functional element, while the tightening of a fastening screw in the tapping of the slide block has the effect of immobilizing this slide block with respect to the rail. When a plurality of functional elements are provided, it suffices to house a plurality of slide blocks in the rail. 
     According to another advantageous aspect of the invention, the support is formed by a metal rail with a cross-section in the form of a C or double C. This geometry of the rail makes it possible to define a volume inside which a slide block may be disposed. The rail advantageously comprises two flanges provided with a flattened free edge on which the slide block may move in abutment. 
     According to another advantageous aspect of the invention, the bogie comprises a chassis extending transversely with respect to the normal direction of movement of the vehicle and in which the elongated rigid support is immobilized. In that case, the chassis may be provided to be of substantially parallelepipedic shape and provided with a recess defining two beams which also extend perpendicularly to this direction of movement and are each provided with at least one elongated rigid support. These two beams may thus serve for fastening the functional elements of the bogies. 
     The invention also relates to a process for manufacturing a bogie as described hereinabove and, more specifically, to a process which consists in disposing, in a mold for manufacturing the bogie before said bogie is cast, an elongated rigid support adapted to removably receive, at a plurality of locations distributed over its length, means for fastening functional elements of the bogie. Thanks to the process of the invention, the elongated rigid support is integrated in the bogie right from the start of its manufacture, while it may be immobilized with respect thereto by any appropriate means and, in particular, by moulding, screwing or gluing. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will be more readily understood on reading the following description of an embodiment of a railway vehicle bogie in accordance with its principle, given solely by way of example and made with reference to the accompanying drawings, in which: 
     FIG. 1 is a side view of a railway vehicle bogie according to the invention; 
     FIG. 2 is a section along line II—II in FIG. 1; 
     FIG. 3 schematically shows, in exploded perspective view, certain structural elements of the bogie of FIGS. 1 and 2; 
     FIG. 4 is a section along line IV—IV in FIG. 3; and 
     FIG. 5 is a section along line V—V in FIG.  3 . 
    
    
     DESCRIPTION OF PREFERRED EMBODIMENT 
     Referring now to the drawings, the bogie  1  shown in FIG. 1 is intended to support a railway vehicle V, shown in dashed and dotted lines, in abutment on rails of which only one, referenced R, is visible in FIG.  1 . This bogie  1  is supported by two wheel and axle sets  3  and  3 ′ grouped on axles represented by axes of rotation A-A′ and B-B′ of the wheels. Side members  4  and  4 ′ are provided to support the chassiss  2  in abutment on axle boxes  5  and  5 ′ of the wheels  3  and  3 ′. 
     The chassis  2  and the side members  4  and  4 ′ are made of composite material, preferably based on epoxide or phenolic resin reinforced with glass, carbon, aramid or equivalent fibers. In this way, the bogie is substantially lighter than conventional steel bogies, while it presents excellent mechanical properties and its cost may be relatively low. 
     Secondary suspension elements  10  are provided to be interposed between the chassis  2  and the box body of the vehicle V. A drive motor  11  and a braking system  12  are also supported by the chassis  2 . Shock absorbers  14  are interposed between moving parts of the bogie  1 . Connecting rods  15  are articulated on the chassis  2  while stops  16  are disposed around a drive pin  17  in order to limit the transverse stroke thereof. Elements  10  to  17  constitute functional elements of the bogie  1 . 
     Depending on the type of bogie, whether it be bearing or driving, on the equipment specific to this type of bogie and on the optional equipment of the vehicle V, the functional elements  10  to  17  or equivalent may be of variable size and shape, this having an influence on their implantation with respect to the chassis  2 . 
     In order to allow such implantation and in accordance with the invention, the chassis  2  is equipped with metal rails or slideways  20  along which the elements  10  to  17  may be fixed. Other elements connected with the functioning of the bogie may also be fixed on the rails  20 . 
     These rails  20  are provided to be integrated in the structure of the chassis  2 , more precisely inside two beams  2   a  and  2   b  of the chassis which extend substantially perpendicularly to the direction of movement of the vehicle V on the rails R, represented by arrow F in FIG.  1 . 
     The rails  20   a  fixed in the beam  2   a  are visible in section in FIG.  4 . There are four rails of substantially C-shaped cross-section which are immobilized with respect to the beam  2   a  thanks to locking screws  21 . Metallic inserts  22  are distributed in the length of the beam  2   a  to receive the screws  21  and thus allow a firm immobilization of the rails  20   a  with respect to the beam  2   a.    
     The cross-section of the rails  20   a  is such that they have two flanges  23  and  24  exposed on the lateral faces of the beam  2   a  and defining therebetween an opening  25 . 
     A plurality of slide blocks  30  are disposed in the inner volume or channel  26  of the rail  20   a  so as to be able to move in translation along the rail. Each slide block  30  is provided with a central tapping  31  placed at the level of the opening  25  so as to receive a fastening screw  32  which, by tightening in the tapping  31 , makes it possible to immobilize a support  33  shaped to wedge a stirrup element  34  of the motor  11  against a flange  23  of the rail  20   a.  The positioning of the motor  11  with respect to the beam  2   a  is effected by moving the or each slide block for fastening the support  33  over the length of the rail  20   a.  In this way, the motor  11  may be fixed at different locations along the rail  20   a.    
     In the same way, a brake bracket  35 , visible in FIG. 3, may be mounted on the rails  20   a  in different positions, as a function of the location of a slide block  30 , over the length of the flanges  23  and  24 . It will be understood that the positioning of the support  33  and of the bracket  35  may be adjusted as a function of the bulk of the elements that they support. 
     The rail system used in the beam  2   b  is partially visible in FIG.  5 . The rail  20   b  of this part of the chassis has a cross-section in the form of a double C and is disposed substantially completely inside the beam  2   b,  while its flanges  43  and  44  are provided with tappings  41  for receiving locking screws  42 . However, the flanges  43  and  44  of the rail  20   b  define a flattened free edge  43   a  or  44   a  intended to overlap on the parts of the beam  2   b  in which the screws  42  are inserted. Reference  45  denotes the opening of the inner volume or channel  46  of the rail  20   b  defined between the edges  43   a  and  44   a.    
     A plurality of slide blocks  50  are disposed in the inner volume  46  of the rail  20   b  so as to be able to move inside this inner volume in abutment on one of the free edges  43   a  and  44   a.  Each slide block  50  is provided with a central tapping  51  intended to receive a fastening screw  52 , which, when tightened, immobilizes a support  53 . 
     It will be understood that a plurality of tapped slide blocks  50  may be introduced in each rail  20   b,  with the result that a plurality of fixing means such as screws for locking the structures  33  or  53  may be positioned at a plurality of locations over the length of the beam  2   b.  In fact, each element  33  or  53  may be positioned at an infinite number of locations over the length of the rail  20   b  thanks to the continuous displacement of the slide block  50 . 
     It will also be understood that, when it is not necessary to provide a support element  33 ,  53  or equivalent, no member projects outside the beams  2   a  and  2   b,  even if the rails  20   b  house slide blocks  30  or  50 . 
     As is clearly visible in FIG. 3, the chassis  2  is substantially parallelepipedic in shape and comprises a central recess or open area  60  of which the two beams  2   a  and  2   b  constitute two borders. The other two borders of the recess  60  are constituted by two hollow beams  2   c  and  2   d  connected to beams  2   a  and  2   b  by the continuity of the composite material forming the chassis  2 . 
     The respective inner volumes  61  and  61 ′ of the hollow beams  2   c  and  2   d  constitute housings for receiving the side members  4  and  4 ′. These housings  61  and  61 ′ may be traversed right through by the side members  4  and  4 ′ in order to connect the axle boxes  5  and  5 ′. 
     The process of manufacture of a bogie as described hereinabove consists essentially in providing to integrate the rails  20  in the chassis  2  as from its molding hase. To that end, one or more rails are disposed in the mold, in the desired configuration. In accordance with the variants of the process of molding, it may be provided to mold the rails in the chassis or to immobilize them with respect to the chassis by gluing or by screwing, as described with reference to FIGS. 3 and 4. 
     The chassis  1  has been described with two types of rails. It is obvious that it may comprise only one type of rail, as shown in FIG. 3 or as shown in FIG. 4, or, on the contrary, more than two types of rails.