Patent Publication Number: US-9421989-B2

Title: Rolling stock

Description:
TECHNICAL FIELD 
     The present invention relates to a rolling stock, and relates specifically to an impact absorbing structure in a rolling stock having a streamlined head shape. 
     BACKGROUND ART 
     A car body of a rolling stock is formed by joining side structures and end structures to four side portions of an underframe, then joining a roof structure to upper portions of the side structures and the end structures, and attaching outside plates, floor plates, interior decorative members, doors, windows, and the like to the structures. In the conventional rolling stock, a passenger compartment is protected by reinforcing the end structures and the underframe portions or by providing impact absorbing members, as collision countermeasures (see for example Patent Document 1). In addition, a rolling stock having a vestibule generally employs a structure in which the vestibule portion is configured as a breakable region (a crushable zone or an impact absorbing part) (see for example Patent Document 2). 
     PRIOR ART DOCUMENTS 
     Patent Documents 
     
         
         Patent Document 1: Japanese Patent Application Publication No. 2001-48016 
         Patent Document 2: Japanese Patent Application Publication No. 2001-26268 
       
    
     SUMMARY OF THE INVENTION 
     Problem to be Solved by the Invention 
     In the case of a general flat-shaped end structure, the strength of the end structure is also improved by thickening the posts or by providing reinforcement members. However, in the case of a cab end structure of a rolling stock in which one of the end structures is formed in a streamlined shape, since the cab end structure is provided with a driver&#39;s cabin, it is impossible to thicken the posts or to provide reinforcement members. Moreover, in the case where there is no vestibule because a passenger compartment continues from the rear of the driver&#39;s cabin, it is difficult to provide a crushable zone including an impact absorbing member. 
     Accordingly, an object of the present invention is to provide a rolling stock including an impact absorbing structure capable of protecting a driver&#39;s cabin and a passenger compartment even when a large external force is applied to a cab end structure formed in a streamlined shape. 
     Means for Solving the Problem 
     To achieve the above-described object, a rolling stock of the present invention is a rolling stock in which a cab end structure, an end structure, an underframe, side structures, and a roof structure are joined together, and the cab end structure is covered with an outside plate having a streamlined shape, the rolling stock including: a pair of left and right post members provided upright on inner sides of left and right end portions of an end beam of the underframe, the end beam being joined to a lower portion of the cab end structure; a recess portion being open frontward, the recess portion being formed in a front portion of the end beam between the pair of post members; and an impact absorbing member disposed between a bottom face of the recess portion and an inner face of the outside plate. 
     Moreover, in the rolling stock of the present invention, 
     the recess portion has such a size that the impact absorbing member is accommodated within the recess portion after being compressively deformed, lower reinforcement members are provided between opposite side faces of a front end portion, on the end beam side, in a center beam of the underframe and lower end portions of the corresponding post members, respectively, and an upper reinforcement member is provided on an upper face of the front end portion, on the end beam side, in the center beam of the under frame, the upper reinforcement member having a trapezoidal shape having a rear end portion corresponding to width dimension of the center beam and a front end portion expanding toward both of the post members. 
     Effect of the Invention 
     According to the rolling stock of the present invention, an external force applied to the front face of the car body can be absorbed by the impact absorbing member provided between the recess portion, which is formed in the front portion of the end beam, and the inner face of the outside plate. Accordingly, it is possible to suppress direct application of the external force to the end beam and to thus protect the driver&#39;s cabin and the passenger compartment located rearward of the end beam. In addition, since the impact absorbing member is disposed on the inner side of the outside plate, the impact absorbing member is not exposed to the outside of the car body, and thus does not impair the design of the car body. Moreover, since the impact absorbing member compressively deformed by the external force is accommodated within the recess portion, the external force does not concentrate on part of the end beam. Accordingly, the external force after the impact absorbing member is compressively deformed can be received by the entire end beam. Furthermore, providing the lower reinforcement member and the upper reinforcement member makes it possible to surely cause the impact absorbing member to be compressively deformed by suppressing deformation of the end beam. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a plan view of an underframe showing one embodiment of a rolling stock of the present invention. 
         FIG. 2  is a side view of a rolling stock structure showing the same. 
         FIG. 3  is a side view showing an appearance of the rolling stock. 
         FIG. 4  is a plan view showing a main part of the underframe. 
         FIG. 5  is a front view of the underframe. 
         FIG. 6  is a cross-sectional side view showing a joint portion between the underframe and a cab end structure. 
     
    
    
     MODES FOR CARRYING OUT THE INVENTION 
     A rolling stock shown in the embodiment is a first rolling stock  10  having a streamlined shape in a front end of a car body. A rolling stock structure  11  forming the first rolling stock  10  includes: an underframe  20 ; a pair of left and right side structures  30  provided on the opposite sides of the underframe  20 ; a cab end structure  40  and an end structure  50  provided respectively on the opposite ends of the underframe  20  and the side structures  30 ; and a roof structure  60  provided to cover upper portions of the side structures  30 , the cab end structure  40 , and the end structure  50 . The cab end structure  40  is formed in a streamlined shape in which an upper half portion is inclined rearward and the opposite side portions are inclined rearward. 
     The underframe  20  includes: a pair of left and right side beams  21  disposed in a rail direction (a front-rear direction of the car body); a pair of front and rear bolster beams  22  disposed in a railroad-tie direction (a width direction of the car body) near the front and rear end portions; center beams  23  provided in a center portion of the underframe  20  in parallel with the side beams  21 ; a plurality of cross beams  24  coupling the side beams  21  and the center beams  23  in the railroad-tie direction; end beams  26  provided respectively on leading ends of the center beams  23  on the car-body opposite end sides of the bolster beams  22 . An impact absorbing member attachment recess portion  72 , which is open frontward for attaching an impact absorbing member  71 , is formed in a front portion of the end beam  26  disposed on the cab end structure  40  side. 
     The side structures  30  include: a plurality of side posts  31  extending in a vertical direction; a plurality of frame members  32  extending in the front-rear direction of the car body; door frame parts  33  forming gate opening portions; and window frame parts  34  forming side-window opening portions. Lower end portions of the side posts  31  are joined to outer faces of the corresponding side beams  21  on lower portion protruding pieces  21   a  protruding sideward from lower ends of the side beams  21  by means of joint members  35 . 
     The cab end structure  40  has a driver&#39;s cabin provided in a center portion in the width direction of the car body. An upper reinforcement beam  41  extending in the railroad-tie direction is provided at a joint portion between an upper end portion of a rear side of the cab end structure  40  and upper end portions of head sides of the side structures  30 . A pair of left and right corner posts  42  are provided in a front end portion of the cab end structure  40  in such a manner as to extend between the opposite end portions of the end beam  26  in the width direction and the opposite end portions of the upper reinforcement beam  41  in the width direction. A pair of left and right end posts  43  are provided at positions on the opposite sides of the driver&#39;s cabin, and on the inner sides of the corner posts  42 , in such a manner as to extend between the end beam  26  and the upper reinforcement beam  41 . On the other hand, the end structure  50  on the rear coupling side is formed in a flat-plate shape, and has a through-hole opening portion provided in a center portion in the width direction. 
     The roof structure  60  is formed of: long girders  61  disposed in the rail direction; a plurality of rafters  62  extending in the railroad-tie direction, which are joined orthogonally to the long girders  61 ; and a roof board  63  joined to outer face sides of the rafters  62 . The long girders  61  are joined to upper end portions of the side structures  30 , and the rafters  62  on the front and rear ends are joined respectively to an upper end portion of the cab end structure  40  and an upper end portion of the end structure  50 . In addition, a front end of the roof structure  60  and upper portions of the end posts  43  are coupled by coupling members  64 . 
     As shown in  FIG. 3 , outside plates  12  having shapes corresponding to the corresponding structures are attached to outer sides of the structures, and rigs and interior decorations, including various instruments and seats, are provided inside and outside the structures. In addition, a passenger door  13  is provided in the door frame part  33  and a side window  14  is provided in the window frame part  34 . A front window  15  is provided in a middle portion of the front face of the cab end structure  40  in the up-down direction, and a crew window  16  is provided in a side face of the cab end structure  40 . A coupling hood  17  is provided around the through-hole opening portion of the end structure  50 . Moreover, couplers  18  are provided respectively on lower portions of the opposite ends of the car body, and an anti-climber  19  is provided in a lower portion of the front face. By mounting required components such as the outside plate  12  inside and outside the rolling stock structure  11  as described above, the streamlined first rolling stock  10  with a rounded head portion having the driver&#39;s cabin at the center in the width direction is formed. 
     The end beam  26  provided in an end portion (front end portion) of the underframe  20  on the cab end structure side includes: a main end beam  26   a , which is continuous in the railroad-tie direction and corresponds to the width of the car body; and reinforcement end beams  26   b ,  26   b  provided on the opposite side portions of a front face of the main end beam  26   a  in such a manner as to form the impact absorbing member attachment recess portion  72 . The impact absorbing member  71 , which absorbs collision energy by being deformed by an external force at the time of collision, is attached to the impact absorbing member attachment recess portion  72  formed on the front face of the main end beam  26   a  between the reinforcement end beams  26   b ,  26   b  in a state where a front end portion of the impact absorbing member  71  is projected from the end beam  26 . 
     As the impact absorbing member  71 , any of various structures can be used as long as it has a sufficient impact absorbing ability, and for example, one disclosed in Japanese Patent Application Publication No. 2010-125858 can be used, which is obtained by combining a plurality of square pipes. The length of the impact absorbing member  71  in the front-rear direction may be such that the front protruding end of the impact absorbing member  71  stays behind the inner face of the outside plate  12  on the rear side, and the thickness of the impact absorbing member  71  may be set depending on the size of the impact absorbing member attachment recess portion  72 . The length and thickness are thus set such that the length of the impact absorbing member  71  in the front-rear direction, which is compressively deformed at the time of collision, is accommodated within the impact absorbing member attachment recess portion  72 . 
     In addition, a pair of left and right corner post reinforcement members  27  for reinforcing lower portions of the corner posts  42  provided in the cab end structure  40  and a pair of end reinforcement posts  28  joined to the lower portions of the end posts  43  are provided on the end beam  26 . A coupler support frame  29  is provided on a center lower portion of the end beam  26 . Each of the end reinforcement posts  28  has a rectangular cross-section long in the front-rear direction in order to withstand impact from the front. A lower portion of each end reinforcement post  28  is passed through a slit  26   c , which is provided in the reinforcement end beams  26   b , and is joined across the front face of the end beam  26  and the front face of the coupler support frame  29 . Further, reinforcement projecting portions  28   a , which are joined to an upper face of the end beam  26 , are provided in rear portions of the end reinforcement posts  28 . In addition, each of the corner post reinforcement members  27  is formed in an L-shaped cross-section. Reinforcement projecting portions  27   a  and  27   b , which project toward the rear side of the car body and the inside of the car body and are joined to upper faces of side end portions of the main end beam  26   a  and upper faces of front end portions of the reinforcement end beams  26   b , are provided respectively on lower portions of the corner post reinforcement members  27 . 
     A pair of lower reinforcement plates  23   a  having plate faces directed in the vertical direction are provided between the opposite side faces of the front end portion, on the end beam  26  side, in the center beam  23  and the lower end portions of the corresponding end posts  43 , respectively. Each of the lower reinforcement plates  23   a  has a rear end portion joined to the side face of the center beam  23  and has a front end portion joined to the rear side of the lower end portion of the end post  43 . In a plan view, the lower reinforcement plates  23   a  are expanded from the joint portions with the center beam  23  to the joint portions with the end posts  43 . In a side view, the lower reinforcement plates  23   a  have a trapezoidal shape in which both end joint portions are vertical, the upper edges are horizontal, and the lower edges are expand downward from the joint portions with the center beam  23  to the joint portions with the end posts  43 . 
     Moreover, an upper reinforcement plate  23   b  is provided in a horizontal direction on an upper face of the front end portion, on the end beam  26  side, in the center beam  23 . The upper reinforcement plate  23   b  has a trapezoidal shape having a rear end portion with a width dimension corresponding to the width dimension of the center beam and a front end portion expanding toward both of the end posts  43 . The front end portion of the upper reinforcement plate  23   b  has a width dimension similar to the width dimension of the end beam  26 , is provided with a center cut portion  23   c  corresponding to the impact absorbing member attachment recess portion  72  between the end posts  43 , and is provided with slits  23   d  corresponding to the slits  26   c  provided in the reinforcement end beams  26   b . Each of the opposite side end portions of the upper reinforcement plate  23   b  extends to the rear portion of the corresponding reinforcement projecting portions  27   a ,  27   b , and is provided with an end cut portion  23   e  accommodating the reinforcement projecting portions  27   a ,  27   b.    
     The end beam  26 , which is provided with the impact absorbing member attachment recess portion  72 , can be reinforced from the rear side by providing the lower reinforcement plates  23   a  and the upper reinforcement plate  23   b  as reinforcement member for the end beam  26 . This makes it possible to prevent the end beams  26  from being deformed prior to the impact absorbing member  71 , and to thus more securely cause the impact absorbing member  71  to be compressively deformed, upon receipt of an external force. 
     The end posts  43  are joined to the end reinforcement posts  28 , and the corner posts  42  are joined to the corner post reinforcement members  27 . Each of the end posts  43  is formed from a solid material made of steel, and includes: a lower post portion  43   a , which extends in the vertical direction and is joined to the end reinforcement post  28 ; a window opening post portion  43   b , which is located on an inner side of the front window  15 ; and an upper post portion  43   c , which extends in the horizontal direction and has a rear end joined to the upper reinforcement beam  41 . 
     Each of the lower post portions  43   a  has a rectangular cross-section long in the front-rear direction in the same manner as the end reinforcement posts  28  to withstand impact from the front like the end reinforcement posts  28 . The lower post portion  43   a  is joined in a state of being placed over a side face of an upper half portion of the end reinforcement post  28 , and is thus joined to the end beam  26  with the end reinforcement post  28  in between. Each of the window opening post portions  43   b  is provided to extend from an upper end of the lower post portion  43   a  while an upper portion of the window opening post portion  43   b  is inclined toward the rear of the car body in conformity with the inclination of the front window  15 . The window opening post portion  43   b  is formed to have a smaller width dimension in the rail direction (the front-rear direction) than the width dimension of the lower post portion  43   a  in the rail direction, so as not to obstruct the driver&#39;s view. Each of the upper post portions  43   c  extends from the rear upper end portion of the window opening post portion  43   b  toward the upper reinforcement beam  41  in the horizontal direction. 
     The corner post  42  is joined in conformity with the corner post reinforcement member  27 . The corner post  42  is also provided such that an upper portion of a portion thereof located on the inner side of the front window  15  is inclined toward the rear of the car body in conformity with the inclination of the front window  15 . 
     In this way, in the rolling stock  10  having the streamlined shape provided with the driver&#39;s cabin in the center portion in the width direction of the car body, the impact absorbing member attachment recess portion  72 , which is open frontward, is provided in the front portion of the end beam  26 , and the impact absorbing member  71  is attached thereto. This makes it possible to bring the impact absorbing member  71  being compressively deformed by external force into a state of being accommodated in the impact absorbing member attachment recess portion  72 . Accordingly, the external force, whose energy has been reduced after the compressive deformation of the impact absorbing member  71 , is made capable of being received by the end beam  26  including the end posts  43 , the end reinforcement posts  28 , and the reinforcement end beams  26   b . Therefore, the driver&#39;s cabin and the passenger compartment, which are locate rearward of the end beam  26 , can be protected. In addition, since the impact absorbing member  71  having a longer length in the front-rear direction can also be accommodated on the inner side of the outside plate  12 , the design unique to the streamlined shape is not impaired by the impact absorbing member  71 . Furthermore, providing the lower reinforcement plates  23   a  and the upper reinforcement plate  23   b  makes it possible to more securely prevent the end beams  26  from being deformed, and to thus effectively conduct energy absorption by securely causing the impact absorbing member  71  to be compressively deformed. 
     Note that, the lower reinforcement member and the upper reinforcement member have not necessarily to be plate-shaped, and any material such as an angular material can be selected as appropriate. Moreover, the lower reinforcement member and the upper reinforcement member may be omitted depending on the shapes and structures of the center beam and the end beam. 
     EXPLANATION OF THE REFERENCE NUMERALS 
     
         
           10  first rolling stock 
           11  rolling stock structure 
           12  outside plate 
           13  passenger door 
           14  side window 
           15  front window 
           16  crew window 
           17  coupling hood 
           18  coupler 
           19  anti-climber 
           20  underframe 
           21  side beam 
           21   a  lower projecting piece 
           22  bolster beam 
           23  center beam 
           23   a  lower reinforcement plate 
           23   b  upper reinforcement plate 
           23   c  center cut portion 
           23   d  slit 
           23   e  end cut portion 
           24  cross beam 
           26  end beam 
           26   a  main end beam 
           26   b  reinforcement end beam 
           26   c  slit 
           27  corner post reinforcement member 
           27   a ,  27   b  reinforcement projecting portion 
           28  end reinforcement post 
           28   a  reinforcement projecting portion 
           29  coupler support frame 
           30  side structure 
           31  side post 
           32  frame member 
           33  door frame portion 
           34  window frame portion 
           35  joint member 
           40  cab end structure 
           41  upper reinforcement beam 
           42  corner post 
           43  end post 
           43   a  lower post portion 
           43   b  window opening post portion 
           43   c  upper post portion 
           50  end structure 
           60  roof structure 
           61  long girder 
           62  rafter 
           63  board 
           64  coupling member 
           71  impact absorbing member 
           72  impact absorbing member attachment recess portion