Patent Publication Number: US-2019176854-A1

Title: Method of assembling a rail vehicle body

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a U.S. non-provisional application claiming the benefit of French Application No. 17 62080, filed on Dec. 13, 2017, which is incorporated herein by reference in its entirety. 
     FIELD OF THE INVENTION 
     The present invention relates to a method of assembling a rail vehicle body, the body comprising at least one chassis module, at least one wall module and at least one roof module. 
     The invention applies more particularly to the bodies of railway vehicles of the tramway, metro and interregional train type. 
     BACKGROUND 
     Railway vehicle bodies comprising one or more wall modules, one or more chassis modules, and one or more roof modules are known. 
     During assembly of the body, these modules are connected together, for example, by welding. However, assembly by welding is likely to cause deformation of the modules and thus makes the assembly of such bodies difficult. 
     To avoid deformation of the body during assembly, it is also known to connect the modules by riveting. 
     In order to achieve this riveting, it is known to counter-drill the rivet holes during the assembly step of the modules. This technique, however, requires the use of a complex assembly station and leads to the production of chips at the assembly stage of the modules. It is then necessary to protect the modules in this step and limit the pre-equipment of the modules. 
     Another known possibility is to make oblong riveting holes prior to the assembly step of the modules, thus providing a tolerance for the positioning of the riveting holes. However, this method also requires a complex assembly station, as well as the presence of several operators to maintain the modules in position in order to perform the riveting correctly, while not offering optimal assembly quality. 
     SUMMARY 
     One object of the invention is to obtain a simplified body assembly method, while ensuring an optimized and precise assembly of the modules. 
     For this purpose, the object of the invention is an assembly method of the aforementioned type comprising the following steps:
         creating a numerical model of at least one specific module among the chassis, wall and roof modules;   dimensioning the position of fixing holes in the specific module in the numerical model, the dimensioning of each fixing hole being defined at least with respect to a specific module edge extending in a direction of greater length of the specific module, and with respect to an axis transverse to the direction of greater length of the specific module, the transverse axis being distinct from the edges of the specific module;   supplying the specific module;   drilling, by a drilling device, of fixing holes in the specific module at the dimensioned position in the numerical model; and   assembling the body by fixing the chassis, wall and roof modules together, the assembly comprising the attachment of the specific module to at least a portion of the adjacent modules to be assembled with the specific module, by means of fasteners inserted into the fixing holes drilled in the specific module.       

     According to particular embodiments of the invention, the assembly method also has one or more of the following characteristics, taken in isolation or according to any technically feasible combination:
         the transverse axis is a median axis of the specific module;   each of the chassis, wall and roof modules is in the form of a specific module, while the drilling step is performed individually for each specific module prior to the assembly step;   each fixing hole is drilled at a distance from the dimensioned position in the numerical model with a diameter localization tolerance of 0.25 mm;   prior to the drilling step, the assembly method comprises a step of locating the ends of the specific module in the direction of greater length of the latter, relative to a reference of the drilling device, which is advantageously a numerically controlled machine tool;   prior to the drilling step, the assembly method comprises a step of aligning the specific module, in particular with respect to areas for receiving the fixing holes; the fasteners are in the form of rivets;   the rivets are one-piece blind rivets;   prior to the step of assembling the body, the assembly method comprises a step of calculating the shear resistance of the fasteners;   the specific module is a pre-equipped module;   the assembly method comprises an additional step of connecting the modules together electrically.       

    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Other features and advantages of the invention will become apparent upon reading the detailed description which follows, given solely by way of example and with reference to the appended drawings, wherein: 
         FIG. 1  shows an exploded view, in perspective, of a rail vehicle body; 
         FIG. 2  shows a view of a specific module with the dimensions of the fixing holes defined according to the invention; 
         FIG. 3  shows a section of a one-piece blind rivet in the disassembled position; 
         FIG. 4  shows a section of a one-piece blind rivet in the assembled position; 
         FIG. 5  shows a flowchart of the method according to the invention. 
     
    
    
     DETAILED DESCRIPTION 
     In the description, the terms “on”, “under”, “above”, “below”, “upper” and “lower” are defined with respect to a direction of elevation of a rail vehicle when it is arranged on rails, i.e. a substantially vertical direction when the rail vehicle is traveling on horizontal rails. The longitudinal direction is defined by the direction of travel of the rail vehicle, while the transverse direction is the direction that is substantially perpendicular to the longitudinal direction and the direction of elevation of the rail vehicle. 
     The rail vehicle body  1  shown in  FIG. 1  comprises a chassis  10 , wall  12 , and end modules  14  and a roof module  16 . 
     It should be noted that in  FIG. 1 , only the wall modules  12  of a first side of the chassis module  10  and roof module  16  are shown, while a single end module  14  is arranged at a first longitudinal end of the chassis  10  and roof  16  modules. However, the body  1  advantageously comprises other wall modules  12  (not shown) that are arranged symmetrically to the visible wall modules  12  on the opposite side of the modules  10  and  16 , and another end module  14  (also not shown), arranged at a second longitudinal end of the chassis  10  and roof  16  modules opposite the first end. 
     Alternatively, the body  1  comprises a single wall module on each side of the chassis  10  and roof  16  modules. 
     The chassis  10 , wall  12 , end  14  and roof  16  modules define an interior space of the body  1  for receiving occupants of the railway vehicle and/or equipment. 
     In one example, the modules  10 ,  12 ,  14 ,  16  comprise electronic devices (not shown). The chassis  10 , end  12 , wall  14  and roof  16  modules are, for example, electrically connected to each other by connectors (not shown). 
     Preferably, at least one of the chassis  10 , wall  12 , end  14  and roof  16  modules is a pre-equipped module. Advantageously, all the chassis  10 , wall  12 , end  14  and roof  16  modules are pre-equipped modules. 
     “Pre-equipped module” is understood to mean a module comprising components assembled prior to assembly of the module to the other modules of the body  1 . 
     A pre-equipped module is, for example, designed to be individually controlled via a control station provided for this purpose, wherein, for example, the installation and/or the correct functioning of components and/or electronic devices of the pre-equipped module is controlled. 
     The chassis module  10  extends in a substantially horizontal plane along a longer direction A-A′. 
     The greatest length of the chassis module  10 , taken in the direction A-A′, is between 10 m and 20 m. 
     The width of the chassis module  10 , in a direction orthogonal to the direction A-A′ is between 2 m and 3 m. 
     The chassis module  10  defines a substantially flat upper face  18  and a substantially flat lower face  20  parallel to the upper face  18 . 
     The upper face  18  is the face of the chassis module  10  which faces the top of the body  1 . 
     The chassis module  10  further defines at least one edge  22  extending parallel to the greater direction A-A′ along one of the upper  18  and lower  20  faces. 
     The chassis module  10  is arranged below the roof module  16  and is substantially perpendicular to the wall  12  and end  14  modules. 
     The chassis module  10  comprises, for example, a metal structure that is designed to support the weight of the occupants or equipment (not shown) of the railway vehicle. 
     The chassis module  10  further comprises a floor located on the upper face  18  of the structure. The floor is typically a surface that is intended to receive occupants of the railway vehicle and/or equipment of the railway vehicle. 
     The chassis module  10  is connected to the wall  12  and the end  14  modules. 
     Each wall module  12  extends in a substantially vertical plane, perpendicular to the transverse direction, along a direction of greater length B-B′. The direction B-B′ is parallel to the direction A-A′. 
     The length of the wall module  12 , taken in the direction B-B′, is between 0.5 m and 3 m. 
     The height of the wall module  12  in a direction orthogonal to the direction B-B′ is between 1.7 m and 2.5 m. 
     Each wall module  12  defines an inner face  24  and an outer face  26  that is opposite to the inner face  24 . 
     The inner face  24  refers to the face of the wall module  12  which is turned towards the inside of the body  1 . 
     The wall module  12  further defines at least one edge  28  extending parallel to the greater direction B-B′ along one of the inner  24  and outer  26  faces of the wall module  12 . 
     A first portion of the wall modules  12  together form a first side wall of the body  1 , while a second portion of the wall modules  12  together form a second side wall of the body  1 , wherein the first and second side walls delimit the internal space  18  transversely. 
     Each wall module  12  comprises a load-bearing structure comprising uprights  30  each of which connects the chassis module  10  to the roof module  16 . These uprights  30  comprise, for example, door pillars each of which delimits an edge of a door formed in one of the side walls of the body  1 . 
     Each wall module  12  further comprises at least one metal sheet  32  fixed between two uprights  30 , and at least one window  34  mounted between two uprights  30 , above a metal sheet  32 . 
     Each wall module  12  comprises an upper edge  36 , a lower edge  38 , and longitudinal edges  40 . 
     The upper edge  36  is connected to the roof module  16 . The lower edge  38  is connected to the chassis module  10 . The connections between the modules  10 ,  12 ,  16  are described in more detail below. 
     The longitudinal edges  40  are formed by the uprights  30 . At least one of the upper  36  and lower  38  edges is defined by an edge  28 . 
     Each end module  14  extends in a substantially vertical plane that is perpendicular to the transverse direction, along a direction of greater length C-C′. The direction C-C′ is orthogonal to the direction A-A′. 
     The greatest length of the end module  14 , taken along the direction C-C′, is between 2 m and 3 m. 
     The height of the end module  14  in a direction orthogonal to the direction C-C′ is between 2 m and 2.9 m. 
     Each end module  14  defines an inner face  42  and an outer face  44  that is opposite the inner face  42 . 
     The inner face  42  is referred to as the face of the end module  14  which is turned towards the inside of the body  1 . 
     The end module  14  further defines at least one edge  46  extending along the longer direction C-C′ on either the inner face  42  or the outer face  46  of the end module  14 . 
     Each end module  14  comprises vertical beams  48  and horizontal beams  50 ,  52 , including a lower beam  50  and an upper beam  52 . 
     Each of the vertical beams  48  is connected to a respective wall module  12 , while the horizontal beam  50  is connected to the chassis module  10 , and the horizontal beam  52  is connected to the roof module  16 . 
     The roof module  16  extends in a substantially horizontal plane along a direction of greater length D-D′. The direction D-D′ is parallel to the direction A-A′. 
     The greatest length of the roof module  16 , taken in the direction D-D′, is between 10 m and 20 m. 
     The width of the roof module  16 , in a direction orthogonal to the direction D-D′ is between 2 m and 3 m. 
     The roof module  16  defines an upper face  52  and a lower face  54  that is opposite to the upper face  52 . 
     The lower face  54  is the face of the chassis module  10  which faces the bottom of the body  1 . 
     The roof module  16  further defines at least one edge  56  extending parallel to the longer length direction D-D′ along one of the upper and lower faces  52  of the roof module  16 . 
     The roof module  16  comprises, for example, a vaulted structure and a sheet fixed to the vaulted structure (not shown). 
     The roof module  16  is connected to the upper edge  36  of each wall module  12  and to the upper beam  52  of each end module  14 . 
     The body  1  also comprises fixing means  58  ( FIG. 4 ) inserted into fixing holes  60  ( FIG. 2 ) formed in the modules  10 ,  12 ,  14 ,  16 , wherein the fastening means  58  connect the various modules  10 ,  12 ,  14 ,  16  between them. 
     In particular, in the case of each pair of adjacent modules  10 ,  12 ,  14 ,  16 , the modules  10 ,  12 ,  14 ,  16  are assembled to each other by at least one fixing means  58  respectively inserted into fixing holes  60  of the modules  10 ,  12 ,  14 ,  16 , as shown in  FIG. 4 . 
     A method of assembling the body  1 , as shown in  FIG. 5 , will now be described. 
     The method of assembling the body  1  comprises a first step  110  of creating a numerical model of at least one specific module  76  among the chassis  10 , wall  12 , end  14  and roof  16  modules. 
     The numerical model is created, for example, by means of computer-aided design (CAD) software. 
     Advantageously, each of the chassis  10 , wall  12 , end  14  and roof  16  modules constitutes such a specific module  76 . 
     The position of the fixing holes  60  in the specific module  76  is dimensioned in the numerical model during a step  120 . 
     The dimensioning of each fixing hole  60  is defined at least with respect to an edge  22 ,  28 ,  46 ,  56  of the specific module  76  extending in the direction of greater length A-A′, B-B′, C-C′, D-D′ of the specific module  76  and with respect to a transverse axis X-X′ in the direction of the greater length of the specific module  76 . The transverse axis X-X′ is distinct from the edges of the specific module  76 . 
     Advantageously, the transverse axis X-X′ is a median axis of the specific module  76 . 
     In the example shown in  FIG. 2 , the specific module  76  is a wall module  12 . The edge  28  used for the dimensioning the fixing holes  60  of this wall module  12  is the edge  28  located on the lower edge  38  of the wall module  12 . 
     In an advantageous embodiment, the assembly method comprises a step  130  for calculating the shear resistance of the fixing means  58 . 
     This step  130  comprises the simulation of external forces that may apply to the body  1 , and the calculation of the resulting shear applied to the fixing means  58 . 
     Then, in a step  140 , the specific module  76  is provided. 
     Advantageously, the assembly method comprises a step  150  of pre-equipment of the specific module, in the course of which the components of the specific module  76  are assembled. 
     Each specific pre-equipped module  76  is then preferably controlled by a control station. For example, the installation or correct operation of the components of the pre-equipped module is controlled. 
     The assembly method then advantageously comprises a step  160  of aligning the specific module  76  in order to flatten the specific module  76 , in particular in the areas intended to receive the fixing holes, in particular to allow optimized assembly of the specific modules  76 . 
     The specific module  76  is then positioned on a drilling device during the step  170 . 
     The drilling device is advantageously a numerically controlled machine tool. 
     “Numerical control” is understood to mean all the hardware and software whose function is to give movement instructions to the machine tool parts, in particular to the milling head. 
     In particular, the numerically controlled machine tool is controlled by means of the numerical model of the specific module  76  and computer-aided manufacturing (CAM) software that defines the path to be traveled by the milling head of the machine tool. 
     The method then comprises the step  180  of locating the ends of the specific module  76  in the direction of greater length of the latter relative to a reference system of the numerically controlled machine tool. The numerically controlled machine tool thus knows the exact position of the specific module  76  relative to the machine. 
     Advantageously, the location of the ends is performed by sensors. 
     Then, during the step  190 , the fixing holes  60  are drilled in the specific module  76  by the numerically controlled machine tool at the positions listed in the numerical model. 
     The milling head of the numerically controlled machine tool is first positioned at a reference axis at the edge  22 ,  28 ,  46 ,  56  and the transverse axis X-X′ of the specific module  76 . Then the milling head moves orthogonally to the reference axis and drills the fixing holes  60  at the locations defined by the dimensioning. 
     The positioning error of the machine tool increases with the distance traveled by the machine tool from the reference axis. However, as the fixing holes  60  are dimensioned with respect to a median axis of the specific module  76  and not from one of the lateral edges, the positioning error is accordingly reduced. In particular for the chassis  10  and roof  16  modules that extend up to more than 15 m, the dimensioning with respect to the median transverse axis X-X′ allows a significant gain in manufacturing tolerance. 
     Advantageously, each fixing hole  60  is thus drilled at a distance from the dimensioned position in the numerical model with a diameter localization tolerance of 0.25 mm. 
     Alternatively, the pre-equipment step  150  may be carried out after the drilling step  190 . 
     The step  190  is followed by a step  200 , in the course of which the body  1  is assembled by fixing the chassis  10 , wall  12 , end  14  and roof  16  modules to each other. 
     This assembly comprises the fixing of the specific module  76  to its adjacent modules by means of the fixing means  58 , which are inserted into the fixing holes  70  drilled in the specific module  76 . 
     Advantageously, the fixing means  58  used for this purpose are dimensioned to withstand the shear stresses calculated during step  130 , throughout the planned life of the body  1 . 
     Moreover, these fixing means  58  are preferably in the form of rivets  62 . 
     When these rivets  62  are provided for insertion into the fixing holes  60 , they are still in a disassembled configuration as shown in  FIG. 3 , wherein they are remote from the fixing holes  60 . Each rivet  62  therefore only comprises a cylindrical portion  64  that is designed to be inserted into a fixing hole  60 , and wherein a first head  66  has a radial extension greater than the diameter of the fixing hole  60 . 
     Then, the cylindrical portion  64  of each rivet  62  is inserted into the fixing holes  60  of at least two separate modules  10 ,  12 ,  14 ,  16 , and is deformed in order to form at the second end of the cylindrical portion  64  a second head  68  with a radial extension that is larger than the diameter of the fixing holes  60 , and wherein the two heads  66 ,  68  are located outside the fixing holes  60 , thus making it possible to secure the two modules  10 ,  12 ,  14 ,  16  together. The rivet  62  is then in an assembled configuration, as shown in  FIG. 4 . 
     Advantageously, each rivet  62  is a one-piece blind rivet. 
     In the disassembled position, as illustrated in  FIG. 3 , the rivet  62  then comprises, in addition to the cylindrical portion  64  and the first head  66 , a rod  70  introduced into the cylindrical portion  64 , wherein the first end of the rod  70  protrudes out of the first head  66 . 
     This rod  70  comprises a head  72  that is arranged at the second end of the rod  70 . The head  72  has a radial extension greater than the diameter of the cylindrical portion  64 . The rod  70  further comprises an area of weakness  74 . 
     When the rivet  62  has been inserted into a hole  60 , the rod  70  is pulled out of the cylindrical portion  64  through the first head  66 , for example by means of a hydraulic rivet pliers. This has the effect that the head  72  of the rod  70  deforms the second end of the cylindrical portion  64  to allow the formation of the second head  68  as shown in  FIG. 4 . When the second head  68  is formed, the rod  70  breaks at the lower area of weakness  74 , and the portion opposite the head  72  of the rod  70  is withdrawn from the cylindrical portion  64 . 
     The assembly of the rivet  62  is thus carried out by manipulating the rivet  62  only on one side of the modules  10 ,  12 ,  14 ,  16  thus making assembly with the one-piece blind rivet  62  fast and simple. 
     The method comprises a final step  210  of electrical connection of the modules  10 ,  12 ,  14 ,  16  to each other. This connection is typically made by direct connection of connectors integrated in the modules  10 ,  12 ,  14 ,  16 . 
     The assembly method described above allows a simple assembly of the modules, and therefore a simplified assembly station. 
     In fact, the drilling of the fixing holes  60  is performed on each module separately before the assembly step to facilitate both drilling and assembly. 
     Moreover, thanks to the numerical model and to the particular dimensioning of the fixing holes, the coaxiality of the fixing holes  60  is guaranteed with very great precision, which also allows optimization of the number of rivets  62  required for the assembly of the body  1 . 
     In addition, this assembly method does not produce chips during assembly, thus making it possible to further equip the modules  10 ,  12 ,  14 ,  16 . 
     The assembly method also does not require the use of a sealing mastic between the modules  10 ,  12 ,  14 ,  16  because of the accuracy of the positioning of the fixing holes  60  and thus good interaction between the adjacent modules. 
     The assembly method described thus allows a simple and precise assembly of the modules  10 ,  12 ,  14 ,  16 .