Patent Application
20180079432
The present invention relates to a carbody of a railcar.
An energy absorber is known, which is attached to a forward/rearward direction (car longitudinal direction) end portion of a carbody underframe of a railcar so as to project forward and absorbs collision energy when the railcar collides with an obstacle (see PTL 1, for example). Such an energy absorber is constituted by, for example, a hollow tubular member. When the railcar collides with the obstacle, the energy absorber causes plastic deformation in a bellows shape to absorb the collision energy.
PTL 1: Japanese Laid-Open Patent Application Publication No. 2015-30336
For example, because of reasons of design, the energy absorber may be provided at a lower side of a vertical center of the underframe. In such a case, when the railcar collides with the obstacle, a moment load in a pitching direction is transferred from the energy absorber to the underframe. In this case, the moment load may push the underframe upward, and the railcar may float up. Further, a structure that supports the energy absorber needs to be strong, and this increases the weight of the carbody.
An object of the present invention to stabilize the posture of a carbody at the time of collision while simplifying the structure of the carbody and reducing the weight of the carbody.
A carbody of a railcar according to one aspect of the present invention includes: an underframe; a first member provided at one of vertical sides of a vertical center of the underframe, supported by the underframe, and absorbing collision energy; a second member provided at the other vertical side of the vertical center of the underframe, supported by the underframe, and contacting an obstacle when the first member is compressed by collision with the obstacle, in a case where the second member receives a reaction force from the obstacle when the first member is compressed by the collision with the obstacle, the second member transferring to the underframe a moment load that is opposite in a rotational direction to a moment load transferred to the underframe by the first member.
According to the above configuration, even when the first member transfers the moment load to the underframe by the collision with the obstacle, the second member transfers the opposite rotational direction moment load to the underframe. Therefore, the moment loads act so as to cancel each other. Thus, the posture of the carbody at the time of collision can be stabilized while simplifying the structure of the carbody and reducing the weight of the carbody.
According to the present invention, the posture of the carbody at the time of collision can be stabilized while simplifying the structure of the carbody and reducing the weight of the carbody.
Hereinafter, embodiments will be explained in reference to the drawings. In the following embodiments, a direction in which a railcar 1 travels, in other words, a direction in which a carbody 2 extends is referred to as a forward/rearward direction (or a car longitudinal direction), and a lateral direction perpendicular to the forward/rearward direction is referred to as a car width direction. The railcar 1 can travel in both directions along the car longitudinal direction. However, in the following explanation, a left direction in
The underframe 4 is provided symmetrically with respect to the car width direction. A plurality of (two, for example) first energy absorbers 8 (first members) projecting forward beyond the underframe 4 are fixed to a front end portion of the underframe 4. The underframe 4 includes a pair of side sills 11, a first end beam 12, a second end beam 13, and second energy absorbers 14A and 14B (third members). The side sills 11 are provided at both respective car width direction sides and extend in the car longitudinal direction. The first end beam 12 is provided at the front end portion of the underframe 4 and extends in the car width direction. The second end beam 13 is provided behind the first end beam 12 (at an inner side in the car longitudinal direction) and extends in the car width direction. The second energy absorbers 14A and 14B connect the first end beam 12 to the second end beam 13.
The first end beam 12 is provided away from front end portions of the side sills 11 in the forward direction. Lower end portions of a pair of collision posts 15 (second members) constituting the head bodyshell 6 are fixed to the first end beam 12. The collision posts 15 are fixed to positions displaced forward with respect to the first end beam 12. In a front surface 12a of the first end beam 12, each of outside portions 12ab located outside the collision posts 15 in the car width direction is inclined rearward as it extends outward in the car width direction. In the front surface 12a of the first end beam 12, a middle portion 12aa located between the collision posts 15 is concave rearward. To be specific, in the front surface 12a of the first end beam 12, portions closest to the collision posts 15 are located frontmost.
The second end beam 13 couples the front end portions of the side sills 11 to each other in the car width direction. The second end beam 13 continuously and linearly extends from one of the side sills 11 to the other side sill 11. A coupler supporting member 16 is fixed to a lower surface of a car width direction middle portion of the second end beam 13. A rear end of a coupler 17 extending forward beyond the first end beam 12 in a plan view is fixed to the coupler supporting member 16. A plurality of (four, for example) second energy absorbers 14A and 14B extend in the forward/rearward direction between the first end beam 12 and the second end beam 13 and are spaced apart from one another in the car width direction.
The second energy absorbers 14A and 14B are made of metal or FRP. Each of the second energy absorbers 14A and 14B has such a structure as to more easily cause plastic deformation by a compressive force in the forward/rearward direction than each of the side sills 11. As one example, each of the second energy absorbers 14A and 14B may have such a structure as to include a plurality of thin portions spaced apart from one another in the forward/rearward direction or may have a known structure. In a side view of the head portion 2a of the carbody 2, each of the second energy absorbers 14A and 14B is provided at a height position overlapping a vertical center of the underframe 4. Specifically, in the side view of the head portion 2a of the carbody 2, each of the second energy absorbers 14A and 14B is provided so as to overlap a center line C of the side sill 11, the center line C extending in the forward/rearward direction.
Absorber supporting members 18 are fixed to respective lower surfaces of car width direction outer sides (right and left sides) of the first end beam 12, the car width direction outer sides being located outside the respective collision posts 15. Each of the absorber supporting members 18 connects the first energy absorber 8 to the first end beam 12 of the underframe 4. The absorber supporting member 18 includes a supporting surface 18a, and the supporting surface 18a supports the first energy absorber 8 from behind. The supporting surface 18a is a vertical surface whose normal line extends in the forward direction, and a rear end of the first energy absorber 8 is fixed to the supporting surface 18a. All the first energy absorbers 8 are provided at a lower side of the vertical center of the underframe 4 and supported by the underframe 4 through the absorber supporting members 18. The first energy absorber 8 is located outside the collision post 15 in the car width direction.
The supporting surface 18a of the absorber supporting member 18 is located behind a front surface of the underframe 4 (i.e., behind the front surface 12a of the first end beam 12). The first energy absorber 8 projects forward beyond the front surface 12a of the first end beam 12 and a front surface 15a of the collision post 15. The first energy absorber 8 is made of metal or FRP. Each of a plurality of (two, for example) first energy absorbers 8 has such a structure as to more easily cause plastic deformation by a compressive force in the forward/rearward direction than each of a plurality of (four, for example) second energy absorbers 14A and 14B. As one example, the first energy absorber 8 has such a tapered shape that a cross-sectional area of the first energy absorber 8 when viewed from front decreases as the first energy absorber 8 extends in the forward direction. The number of first energy absorbers 8 is smaller than the number of second energy absorbers 14A and 14B. Anti-climbers 19 are provided at respective front surfaces of the first energy absorbers 8. Each of the anti-climbers 19 is constituted by a plurality of plates that are spaced apart from one another in the vertical direction and extend in the car width direction.
The head bodyshell 6 includes the pair of collision posts 15, pillars 20, and side beams 21. The collision posts 15 project upward from the first end beam 12. Each of the pillars 20 extends from an upper end of the collision post 15 to the roof bodyshell 7. Each of the side beams 21 extends from a car width direction end portion of the first end beam 12 to a front end of the side bodyshell 5 obliquely upward and rearward. The collision posts 15 are provided at an upper side of the vertical center (center line C) of the underframe 4. The front surface 15a of the collision post 15 is a vertical surface whose normal line extends in the forward direction. In a side view of the head portion of the carbody, a rear surface 15b of the collision post 15 is inclined rearward as it extends downward. In a plan view of the head portion 2a of the carbody 2, the collision post 15 is provided so as to project forward beyond a portion P of the front surface 12a of the first end beam 12 (i.e., the front surface of the underframe 4), the portion P being the same in position in the car width direction as a car width direction center of the first energy absorber 8. A front end (front surface 15a) of the collision post 15 is located behind a front end of the first energy absorber 8 and in front of the rear end of the first energy absorber 8. Specifically, in a forward/rearward direction positional range from the front end of the first energy absorber 8 in a noncompressed state (before deformation) to the rear end thereof, when the position of the front end of the first energy absorber 8 is defined as a 0% position, and the position of the rear end of the first energy absorber 8 is defined as a 100% position, the position of the front end of the collision post 15 is set within a range from a 40% position to an 80% position. In the present embodiment, the collision post 15 is provided such that the position of the front end of the first energy absorber 8 when the first energy absorber 8 is compressed by an effective stroke amount becomes substantially the same as the position of the front end of the collision post 15. To be specific, the collision post 15 is provided so as to contact an obstacle when the first energy absorber 8 is compressed by the effective stroke amount by the collision with the obstacle. The effective stroke amount denotes a maximum compressed length in the forward/rearward direction when the energy absorber is compressed in the forward/rearward direction by collision to cause plastic deformation. It should be noted that the collision post 15 does not have to be provided so as to contact the obstacle when the first energy absorber 8 is compressed by the effective stroke amount by the collision with the obstacle. The first energy absorber 8 may be provided so as to contact the obstacle when the first energy absorber 8 is compressed by a stroke amount (predetermined stroke amount) that is smaller than the effective stroke amount.
The pillar 20 is inclined rearward as it extends upward. Therefore, the front surface 15a of the collision post 15 is located in front of the front surface 20a of the pillar 20. A vertical length of the collision post 15 is shorter than a vertical length of the pillar 20. A vertical distance L1 from a vertical center of the collision post 15 to the vertical center of the underframe 4 is longer than a vertical distance L2 from a vertical center of the first energy absorber 8 to the vertical center of the underframe 4. A total area S1 of the front surfaces 15a of the collision posts 15 located at an upper side of the underframe 4 is larger than a total area S2 of regions 12ac of the front surface (the front surface 12a of the first end beam 12) of the underframe 4, the regions 12ac being included in a virtual vertical surface including the front surfaces 15a of the collision posts 15. The total area S2 may be set to zero by providing the front surfaces 15a of the collision posts 15 in front of the front surface 12a of the first end beam 12.
According to the configuration explained as above, even when the first energy absorber 8 transfers the moment load M1 to the underframe 4 by the collision with the obstacle X, the collision post 15 transfers the opposite rotational direction moment load M2 to the underframe 4. Therefore, the moment loads M1 and M2 act so as to cancel each other. Thus, the posture of the carbody 2 at the time of collision can be stabilized while simplifying the structure of the carbody 2 and reducing the weight of the carbody 2. Further, since the moment load M2 acts so as to cancel the moment load M1, the absorber supporting member 18 can be simplified and reduced in weight. Furthermore, since a post member (collision post 15) constituting the bodyshell is utilized as a member that generates the moment load M2, the number of parts can be reduced.
The moment load M1 of the first energy absorber 8 and the moment load M2 of the collision post 15 act so as to cancel each other, and therefore, the posture of the first end beam 12 is stabilized. On this account, when an impact is high, the second energy absorbers 14A and 14B are compressed in a correct posture and can efficiently absorb the collision energy. Further, the vertical distance L1 from the vertical center of the collision post 15 to the vertical center of the underframe 4 is longer than the vertical distance L2 from the vertical center of the first energy absorber 8 to the vertical center of the underframe 4. Therefore, the moment load M2 transferred from the collision post 15 to the underframe 4 is effectively generated, and the floating of the carbody 2 by the moment load M1 transferred from the first energy absorber 8 to the underframe 4 can be appropriately prevented.
An absorber supporting member 109 extending upward from the end beam 112 is provided at a head bodyshell 106 that connects the end beam 112 to a roof bodyshell 107. The absorber supporting member 109 connects an energy absorber 115 (second member) to the end beam 112. The absorber supporting member 109 includes a supporting surface 109a, and the supporting surface 109a supports the energy absorber 115 from behind. The supporting surface 109a is a vertical surface whose normal line extends in the forward direction, and a rear end of the energy absorber 115 extending forward is fixed to the supporting surface 109a. The energy absorber 115 is provided at an upper side of a vertical center (center line C) of the underframe 104. A front end 115a of the energy absorber 115 is located behind a front end 117b of the coupler 117 and in front of a rear end 117c of the coupler 117.
An absorber supporting member 216 is fixed to a lower surface of the end beam 112. A rear end of a second energy absorber 215 (second member) extending forward is fixed to the absorber supporting member 216. To be specific, the second energy absorber 215 is provided at a lower side of the vertical center (center line C) of the underframe 104. A front end 215a of the second energy absorber 215 is located behind a front end of the first energy absorber 217 and in front of the rear end of the first energy absorber 217.
A pair of projecting posts 315 (post members) project upward from the end beam 312. A driver's cab 323 is provided in a space located immediately above the projecting posts 315. Upper ends of the projecting posts 315 are free ends. Each of the projecting posts 315 is supported by the end beam 312 from below and is also supported by a center sill 322 from below, the center sill 322 connecting the end beam 312 to a bolster beam 321. The projecting post 315 has such a shape as to decrease in height as it extends rearward. A front surface 315a of the projecting post 315 is a vertical surface whose normal line extends in the forward direction. In the front surface 312a of the end beam 312, portions closest to the projecting posts 315 are located at frontmost.
The front surface 315a of the projecting post 315 is located in front of a front end of a side bodyshell 305. The front surface 315a of the projecting post 315 is located behind the front end of the first energy absorber 8 and in front of the rear end of the first energy absorber 8. The projecting post 315 is provided so as to contact the obstacle when the first energy absorber 8 is compressed by the effective stroke amount by the collision with the obstacle. According to this, even when the first energy absorber 8 transfers the moment load to the underframe 304 by the collision with the obstacle, the projecting post 315 transfers the opposite rotational direction moment load to the underframe 304. Therefore, these moment loads act so as to cancel each other. Thus, the posture of the carbody 302 at the time of collision can be stabilized.
The front surface 412a of the end beam 412 of the underframe 404 extends linearly in the car width direction. A lower end portion of an end bodyshell 406 is fixed to the end beam 412. The end bodyshell 406 includes: an end outside plate 424 at which a gangway 424a opens; and corner posts 415 (post members) each fixed to a car width direction end portion of the end outside plate 424 and projecting upward from a car width direction end portion of the end beam 412. A front surface 415a of the corner post 415 is the same in position in the forward/rearward direction as the front surface 412a of the end beam 412 or is located in front of the front surface 412a of the end beam 412. The front surface 415a of the corner post 415 is a vertical surface whose normal line extends in the forward direction. The front surface 415a of the corner post 415 is located behind the front end of the first energy absorber 8 and in front of the rear end of the first energy absorber 8. The corner post 415 is provided so as to contact the obstacle when the first energy absorber 8 is compressed by the effective stroke amount by the collision with the obstacle.
As shown in
The above embodiments may be combined arbitrarily. For example, a part of components in one embodiment may be applied to other embodiment. For example, the carbody may include the first energy absorber 8 of Embodiment 1 and the coupler 117 of Embodiment 2, and both the first energy absorber 8 and the coupler 117 may absorb the impact at the time of collision with the obstacle X. Further, the car may be configured such that a head portion thereof has the configuration of
1 railcar
2, 102, 202, 302, 402 carbody
4, 104, 304, 404 underframe
8, 217 first energy absorber (first member)
12 first end beam
13 second end beam
14A, 14B second energy absorber (third member)
15 collision post (second member, post member)
16, 116 coupler supporting member
18, 109, 216 absorber supporting member
18
a supporting surface
115, 215 energy absorber (second member)
117 coupler (first member)
315 projecting post (post member)
415 corner post (post member)
C center line
M1, M2 moment load
X obstacle
| Number | Date | Country | Kind |
|---|---|---|---|
| 2015-112946 | Jun 2015 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2016/002622 | 5/31/2016 | WO | 00 |
