U.S. patent application number 10/067913 was filed with the patent office on 2003-03-27 for railway car.
Invention is credited to Ohba, Hideshi, Okuno, Sumio, Yamaguchi, Takeshi, Yamamoto, Takahisa.
Application Number | 20030056683 10/067913 |
Document ID | / |
Family ID | 19113430 |
Filed Date | 2003-03-27 |
United States Patent
Application |
20030056683 |
Kind Code |
A1 |
Yamaguchi, Takeshi ; et
al. |
March 27, 2003 |
Railway car
Abstract
A front end portion 100 is disposed on the front end of a car
body. The floor thereof consists of hollow shape members 200 that
construct a shock absorber 200. The shock absorber 200 includes an
upper shock absorber 200 and a lower shock absorber 200. Annealed
hollow shape members are used to form the hollow shape member 210.
The hollow shape members 210 have their longitudinal directions
disposed along the longitudinal directions of the car body. Plural
hollow shape members 210 are arranged next to one another in the
width direction, and bonded together by friction stir welding. When
the hollow shape members receive impact load, the members 210
deform into an accordion-like shape, absorbing the impact force. At
this time, the friction stir welded portions also receive the
impact force, but dislike other weld joints, cracks are not created
at the friction-stir-weld joints, and the weld joints do not
prevent the hollow shape members 210 from deforming into an
accordion-like shape.
Inventors: |
Yamaguchi, Takeshi;
(Kudamatsu-shi, JP) ; Ohba, Hideshi; (Kumage-gun,
JP) ; Okuno, Sumio; (Kudamatsu-shi, JP) ;
Yamamoto, Takahisa; (Kudamatsu-shi, JP) |
Correspondence
Address: |
ANTONELLI TERRY STOUT AND KRAUS
SUITE 1800
1300 NORTH SEVENTEENTH STREET
ARLINGTON
VA
22209
|
Family ID: |
19113430 |
Appl. No.: |
10/067913 |
Filed: |
February 8, 2002 |
Current U.S.
Class: |
105/75 |
Current CPC
Class: |
B61F 1/10 20130101; B61D
15/06 20130101 |
Class at
Publication: |
105/75 |
International
Class: |
B61C 011/00 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 25, 2001 |
JP |
2001-291255 |
Claims
What is claimed is:
1. A railway car characterized in that: a member constituting the
floor at an end portion of the car body is a shock absorber; said
shock absorber comprises plural extruded shape members having
hollow portions; said hollow extruded shape members include plural
hollow portions arranged along the width direction of the car body;
said hollow extruded shape members are disposed so that the
direction of extrusion thereof is arranged along the longitudinal
direction of the car body; said hollow shape members are opposed to
the underframe of said car body; and said shock absorber is
disposed as upper and lower layers.
2. A railway car according to claim 1, wherein the front ends of
said upper and lower layers of shock absorbers are connected to one
member.
3. A railway car according to claim 1, wherein the shock absorber
constituting the lower layer is divided into left and right parts;
and a coupler for connecting cars is disposed between the left and
right shock absorbers.
4. A railway car according to claim 1, wherein the shock absorber
disposed at the front end portion of a leading car is positioned
ahead of the seat of a driver's cab.
5. A railway car according to claim 4, wherein driving equipment is
mounted above said shock absorber.
6. A railway car according to claim 4, wherein the front and rear
ends of said hollow shape members are fixed to one or more pillars
supporting a roof structure at said front end portion.
7. A railway car according to claim 6, wherein said pillars fixed
to the front end of said hollow shape members are welded to spaces
formed by notching said hollow shape members.
8. A railway car characterized in that: a member constituting the
floor at a front end portion of a leading car is a shock absorber;
said shock absorber comprises plural extruded shape members having
hollow portions; said hollow extruded shape members include plural
hollow portions arranged along the width direction of the car body;
said hollow extruded shape members are disposed so that the
direction of extrusion thereof is arranged along the longitudinal
direction of the car body; said hollow shape members are opposed to
the underframe of said car body; and said shock absorber disposed
at the front end portion is positioned ahead of the seat in a
driver's cab.
9. A railway car according to claim 8, wherein driving equipment is
mounted above said shock absorber.
10. A railway car characterized in that: a member constituting the
floor at an end portion of the car body is a shock absorber; said
shock absorber comprises plural extruded shape members having
hollow portions; said hollow extruded shape members include plural
hollow portions arranged along the width direction of the car body;
said hollow extruded shape members are disposed so that the
direction of extrusion thereof is arranged along the longitudinal
direction of the car body; said hollow shape members are opposed to
the underframe of said car body; and said underframe comprises side
sills, and said end portion does not include hollow shape members
having the same size as said side sills disposed on the line of
extension of said side sills.
11. A railway car according to claim 10, wherein at said end
portion, the plates constituting the width-direction side surfaces
of the car body covers the side surfaces of said shock
absorber.
12. A railway car characterized in that: a member constituting the
floor at an end portion of the car body is a shock absorber; said
shock absorber comprises plural extruded shape members having
hollow portions; said hollow extruded shape members include plural
hollow portions arranged along the width direction of the car body;
said hollow extruded shape members are disposed so that the
direction of extrusion thereof is arranged along the longitudinal
direction of the car body; said hollow shape members are opposed to
the underframe of said car body; and a member used in a coupler for
connecting the cars together is equipped to the lower surface of
said underframe.
13. A railway car characterized in that: said railway car comprises
a car formation in which plural car bodies are connected; a member
constituting the floor at an end portion of each of said car bodies
is a shock absorber; said shock absorber comprises plural extruded
shape members having hollow portions; said hollow extruded shape
members include plural hollow portions arranged along the width
direction of the car body; said hollow extruded shape members are
disposed so that the direction of extrusion thereof is arranged
along the longitudinal direction of the car body; said hollow shape
member is opposed to the underframe of said car body; and the
number of shock absorbers equipped in a car body disposed near the
end of said car formation is greater than the number of shock
absorbers equipped in a car body disposed near the center of said
car formation.
14. A car formation characterized in that: said car formation
comprises plural car bodies being connected; a member supporting
the floor at an end portion of each of said car bodies is a shock
absorber; and the vertical cross-sectional area of the member
constituting said shock absorber equipped in a car body disposed
near the end of said car formation is greater than the vertical
cross-sectional area of the member constituting said shock absorber
equipped in a car body disposed near the center of said car
formation.
15. A car formation according to claim 14, characterized in that:
said shock absorber comprises plural extruded shape members having
hollow portions; said hollow extruded shape members include plural
hollow portions arranged along the width direction of the car body;
said hollow extruded shape members are disposed so that the
direction of extrusion thereof is arranged along the longitudinal
direction of the car body; and said hollow shape members are
opposed to the underframe of said car body.
16. A railway car characterized in that: said railway car comprises
a car formation in which plural car bodies are connected; a member
supporting the floor at an end portion of each of said car bodies
is a shock absorber; and an entrance is formed above said shock
absorber.
17. A railway car according to claim 16, characterized in that:
said shock absorber comprises plural extruded shape members having
hollow portions; said hollow extruded shape members include plural
hollow portions arranged along the width direction of the car body;
said hollow extruded shape members are disposed so that the
direction of extrusion thereof is arranged along the longitudinal
direction of the car body; and said hollow shape members are
opposed to the underframe of said car body.
18. A railway car characterized in that: said railway car comprises
a car formation wherein plural car bodies are connected; a member
supporting the floor at an end portion of each of said car bodies
is a shock absorber; and a control panel is equipped above said
shock absorber.
19. A railway car according to claim 18, wherein a member
constituting the floor at an end portion of the car body is a shock
absorber; said shock absorber comprises plural extruded shape
members having hollow portions; said hollow extruded shape members
include plural hollow portions arranged along the width direction
of the car body; said hollow extruded shape members are disposed so
that the direction of extrusion thereof is arranged along the
longitudinal direction of the car body; and said hollow shape
members are opposed to the underframe of said car body;
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a body of a railway car
that travels on rails, and is especially preferable for forming a
railway car body using hollow shape members made of light
alloy.
DESCRIPTION OF THE RELATED ART
[0002] In forming a railway car, it is required to consider
applying means for absorbing and easing the impact force loaded to
the passengers on board when collision occurs. Japanese Patent
Laid-Open Publication No. H7-186951 (U.S. Pat. No. 5,715,757)
discloses absorbing the energy generated by the impact of the
collision to the front end of the leading car by the deformation
thereof. This reliever comprises triangular elements and honeycomb
panels disposed within a plane perpendicular to the direction of
impact, and has various designs. A plural number of relievers is
positioned either in parallel relations against the direction of
impact or linearly along the direction of impact.
[0003] A welding method called a friction stir welding method is
proposed as a means to weld members, and this method is also
applied to forming railway cars. This method is disclosed in
Japanese Patent No. 3014654 (EP 0797043 A2).
[0004] According to the disclosure of Japanese Patent Laid-Open
Publication No. H11-51103, when friction stir welding is performed
to members, the metal constitution of the friction-stir-welded
portion becomes refined, and the energy absorption rate is
improved.
[0005] In the disclosure, friction stir welding is performed in a
ring-like or spiral-like manner to the extruded hollow shape member
made of aluminum alloy, and the welded member is used as the
steering shaft of an automobile. Friction stir welding is performed
in the direction perpendicular to the direction of the impact
energy, and the friction-stir-welded portion absorbs the impact
force. Moreover, a plurality of short pipe-like members is arranged
linearly along the direction of impact energy, and the members are
friction-stir-welded so as to form a shaft.
SUMMARY OF THE INVENTION
[0006] The above-mentioned Japanese Patent Laid-open Publication
No. H7-186951 (U.S. Pat. No. 5,715,757) proposes a reliever to be
mounted on a railway car that is meant to absorb the impact of
collision. This reliever comprises plural relieving devices,
thereby realizing the safety of the passengers on board.
[0007] Since the reliever is mounted on the railway car body, the
length of the reliever should preferably be short so as to secure
space for the passengers.
[0008] The present invention aims at providing a railway car that
is capable of absorbing the impact energy.
[0009] The above object can be achieved by a railway car
characterized in that:
[0010] a member constituting the floor at an end portion of the car
body is a shock absorber;
[0011] the shock absorber comprises plural extruded shape members
having hollow portions;
[0012] the hollow extruded shape members include plural hollow
portions arranged along the width direction of the car body;
[0013] the hollow extruded shape members are disposed so that the
direction of extrusion thereof is disposed along the longitudinal
direction of the car body;
[0014] the hollow shape members are opposed to the underframe of
said car body; wherein
[0015] the shock absorber is disposed as upper and lower
layers,
[0016] or by providing no hollow shape member to the region
equipped with the shock absorber corresponding to side sills
provided to other regions,
[0017] or by not connecting the coupler for coupling cars together
with the shock absorber,
[0018] or by increasing the number or the vertical cross-sectional
area of the shock absorbers provided to the leading car compared to
the number or the vertical cross-sectional area of the shock
absorbers provided to the middle cars.
[0019] Moreover, the object of the present invention can be
achieved by a car formation comprising plural car bodies being
connected;
[0020] a member supporting the floor at an end portion of each of
said car bodies is a shock absorber; wherein
[0021] an entrance or a control panel is positioned above the shock
absorber, or
[0022] the vertical cross-sectional area of the shock absorber near
the leading car is greater than the vertical cross-sectional area
of the shock absorber equipped in the middle cars.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] FIG. 1 is a side view showing the car formation of the
railway car according to one embodiment of the present
invention;
[0024] FIG. 2 is a side view showing the state in which the front
end portion of FIG. 1 is separated;
[0025] FIG. 3 is a plan view showing the front end portion of FIG.
2;
[0026] FIG. 4 is a left side view of FIG. 2;
[0027] FIG. 5 is a V-V cross-sectional view of FIG. 3;
[0028] FIG. 6 is a VI-VI cross-sectional view of FIG. 4;
[0029] FIG. 7 is a VII-VII cross-sectional view of FIG. 6;
[0030] FIG. 8 is a VIII-VIII cross-sectional view of FIG. 6;
[0031] FIG. 9 is a drawing showing the method of welding the shock
absorber of FIG. 1;
[0032] FIG. 10 is an explanatory view showing the impact energy of
the material; and
[0033] FIG. 11 is a stress-flexure diagram of the materials.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0034] One embodiment of the present invention will now be
explained with reference to FIGS. 1 through 9. In FIG. 1 and FIG.
2, the leading portion is separated from the car body so that the
present invention can be understood more easily.
[0035] The present car formation comprises two leading cars A that
are disposed at the front and back ends of the car formation, and
middle cars B, the number of which varies according to need. A
front end portion 100 of the leading car A is curved and projected
in an arc-like shape toward the forward direction. A shock absorber
200 is mounted to the front end portion 100. Further, shock
absorbers 400, 400 are respectively arranged between the rear end
(other end) of each leading car body A and the end of the middle
car B adjacent thereto. First, the shock absorber 200 mounted to
the front end portion 100 will be explained in detail.
[0036] A car body 90 excluding the front end portion 100 comprises
side structures 10 that constitute the sides of the car body, the
roof structure 20, an underframe 30 that constitutes the floor
thereof, and so on. The side structures 10, the roof structure 20,
and the underframe 30 are all formed by welding plural hollow shape
members together. Each hollow shape member is an extruded shape
member made of light alloy (such as aluminum alloy), and the
direction of extrusion (that is, the longitudinal direction) is
arranged along the longitudinal direction of the car body. Plural
hollow shape members are arranged along the circumference direction
of the car body with the width direction of the members positioned
adjacent to each other, and the members are welded to form a single
structure. At the end of the car body 90 is provided a seat 40 for
fixing the front end portion 100. The space 80 provided at the
forward end of the car body 90 is the driver's cab, and a driver's
seat 85 is mounted to the floor formed above the underframe 30.
[0037] The front end portion 100 comprises a frame 110 for locking
the portion to the car body, plural pillars 120, 130, plural cross
beams 140, a shock absorber 200, an anticlimber 250, and so on. The
frame 110 has four sides, and the upper side is U-shaped. The frame
110 is removably fixed to the seat 40 of the car body 90 by bolts.
The pillars 120 connect the upper end of the frame 110 and the
front end of the shock absorber 200. The pillars 120 are positioned
near the center of the car body when seen from the front of the
body. The pillars 120 are disposed on both sides of a coupler 70.
The pillars 130 connect the upper portion of the frame 110 and the
sides of the shock absorber 200. The pillars 130 are placed at the
center portion in the longitudinal direction of the shock absorber
200, and is connected to both side surfaces of the car body. Since
the pillars 120 are likely to collide against obstacles, they are
designed to be larger and stronger than the pillars 130. The cross
beam 140 is disposed at the center of height of the frame 110 and
connects the frame 110 and the pillars 130, 120. These connecting
portions are welded together. The area composed of the frame 110,
the pillars 120 and 130, and the cross beam 140 is covered smoothly
by plates or glass material (not shown).
[0038] The rear end of the shock absorber 200 is abutted against
and welded to the lower edge of the frame 110. The shock absorber
200 is composed of two layers, an upper layer and a lower layer.
The lower portion of the shock absorber 200 is welded onto a seat
115 arrange in parallel therewith at a position below the lower
edge of the frame 110. The seat 115 is welded onto the lower edge
of the frame 110.
[0039] The side structure 10, the roof structure 20, and the
underframe 30 are made by welding plural hollow extruded shape
members made of light alloy (such as aluminum alloy). Especially,
the underframe 30 is formed strongly. The lower edge of the seat 40
is designed to have the same shape as the seat 115. The back
surface of the seat 40 and the lower surface of the underframe 30
are connected strongly by plural stays 45.
[0040] The upper shock absorber 200 is opposed to the seat 40 of
the underframe 30 through the lower edge of the frame 110. The
lower shock absorber 200 is opposed to the lower portion of the
seat 40 of the underframe 30 through the seat 115.
[0041] The front end of the upper and lower shock absorbers 200,
200 is welded onto an anticlimber 250. The front end of the
anticlimber 250 has projections and recesses, preventing the
obstacle that collides against the body from moving upward. A
rubber shock absorbing unit is mounted between the front end of the
anticlimber 250 and the shock absorbers 200, 200.
[0042] The shock absorber 200 is not only designed to have two
(upper and lower) layers, but is also divided into left and right
portions when observed from the front of the car body. The space
between the left and right shock absorbers 200, 200 of the lower
layer constitutes the space through which the coupler 70 of the car
passes. The upper shock absorbers 200, 200 also have a space formed
therebetween, the upper portion of which mounting a plate 150 that
is used as the floor for mounting equipment. The plate 150 is fixed
to the upper shock absorbers 200, 200. Further, the plate 150 is
mounted on a support seat 151 fixed to the upper shock absorbers
200, 200. There are plural support seats 151 at predetermined
intervals along the longitudinal direction of the car body. The
plate 150 can cover the whole surface of the shock absorbers 200,
200.
[0043] Moreover, it is also possible to place a shock absorber
between the two upper layer shock absorbers 200, 200, being
integrally formed with the left and right shock absorbers 200, 200.
In this case, there is no need to provide the plate 150 and support
seats 151. Moreover, the anticlimber 250 can be mounted on the
front end side of the added shock absorber 200.
[0044] The shock absorber 200 comprises a hollow extruded shape
member 210 made of light alloy (such as aluminum alloy). The hollow
shape member 210 is arranged so that the direction of extrusion
thereof is arranged along the direction of travel (the longitudinal
direction) of the car body. The hollow portion is oriented along
the longitudinal direction. A plurality of hollow shape members
210, 210 are assembled along the width direction of the car body.
The width-direction-ends of the hollow shape members 210 are welded
to one another. Each shock absorber 200 comprises two hollow shape
members.
[0045] The hollow shape member 210 comprises two face plates 211
and 212, connecting plates 213 connecting the two face plates and
being slanted against the two face plates 211 and 212, and a
connecting plate 215 substantially orthogonal to the face plates
211 and 212 disposed at the width-direction-end thereof. The face
plates 211, 212 and the connecting plates 213 constitute trusses.
The connecting plate 215 is disposed to one of the two hollow shape
members at the joint between the two members.
[0046] The hollow shape members 210 are welded together by friction
stir welding. The welding direction is along the longitudinal
direction thereof. A segment 216 protrudes toward the end side at
the joint between the face plate 211 (212) and the connecting plate
215. The end side portion of the connecting plate 215 is recessed
than the outer surface of the face plates 211, 212. The projecting
segment 216 is formed to this recessed position. The face plates
211, 212 of the other hollow shape member 210 overlap with the
recessed portion. The face plates 211 and 212 of the two hollow
shape members are each abutted against the corresponding face
plate, respectively. The end surface of the face plates 211, 212 of
the hollow shape member 210 where the connecting plate 215 is
formed (the surface including the recessed portion) is
substantially disposed on the extension of the center of plate
thickness of the connecting plate 215. The outer surfaces at the
end of face plates 211 and 212 being abutted against the other
hollow shape member are provided with projections 217 that protrude
in the thickness direction of the hollow shape member. The
projections 217 on the two hollow shape members are also abutted
against one another.
[0047] Friction stir welding will now be explained. One pair of
hollow shape members 210, 210 is mounted on a bed 300. The lower
projections 217, 217 of the members are mounted on the bed 300. The
butt joint is temporarily welded by arc welding along the
longitudinal direction thereof. The upper abutted portion is
friction-stir-welded using a rotary tool 310. The lower end of a
large-diameter portion of the rotary tool 310 is positioned between
the outer surface of the face plate 211 (212) and the apex of the
projections 217, 217. The remaining projection can be removed if
necessary by cutting. After friction-stir-welding the upper
portion, the hollow shape members 210, 210 are turned up-side down,
and friction stir welding is performed to the opposite side in a
similar manner. The projections 217 can be omitted.
[0048] The hollow shape member 210 is for example a member for
forming the underframe 30. One or more hollow shape members are
used to form the necessary width of the shock absorber 200 (the
width direction of the car body). If necessary, the width of the
hollow shape member can be cut off. It is best that the with
direction of the shock absorber 200 is flat, so the hollow shape
member for the underframe 30 is preferred. However, the side sill
of the underframe 30 will not be used. Further, the side structure
10 also includes linear hollow shape members, which can also be
used as the present shock absorber. The cost of the shock absorber
is inexpensive since the hollow shape members for forming the other
parts of the car body can be applied.
[0049] The hollow shape member 210 of the shock absorber 200 is
softer than the hollow shape members constituting the underframe
30, the side structures 10, or the roof structure 20, and can
easily collapse during collision, thereby absorbing the energy of
the impact. The hollow shape member 120 is formed by annealing and
softening the hollow shape member used to create the
underframe.
[0050] The annealing can be, for example, an O-material treatment
(temper of annealed metal). In general, various heat treatments are
provided to the extruded member after the extrusion. If the
material of the extruded member is A6N01, an artificial aging and
hardening process of T5 is performed. The annealing of the
O-material is performed thereafter. The annealing treatment to the
O-material is performed for two hours at 380.degree. C., and the
strength is 36.8 MPa. T5 has a strength of 245 MPa. The annealing
of the O-material is meant to soften the material as the hollow
shape member. The elongation of the hollow shape member 210 is
greater than that of the general hollow shape member. The strength
of the hollow shape member 210 is smaller than that of the general
hollow shape member. In order to provide necessary strength and
softness to the member, annealing other than the O-material can
also be performed. Further, the plate thickness of the hollow shape
member can also be chosen to provide the best performance.
[0051] The lowermost end of the pillars 120 and 130 are welded to
the upper and lower hollow shape members 210, 210. Welding is
performed by forming notches to the upper and lower hollow shape
members 210 having a shape corresponding to the pillars 120 and
130, and then welding the members. The width-direction-ends of the
upper and lower hollow shape members 210, 210 are welded to plural
members 250.
[0052] The surface of the anticlimber 250 facing the hollow shape
members 210 is provided with plural pipes 256, which are inserted
to the plural hollow portions of the hollow shape members 210. The
outer diameter of each pipe 256 is substantially equal to the
inscribing circle of the hollow portion having a triangular
cross-section. The pipes 256 are inserted to every other triangular
hollow shape portion. The pipes 256 are welded onto the seat 253 of
the anticlimber 250 while being inserted to the holes formed to the
seat 253. The frame 110 and the seat 115 also have pipes 256, which
are inserted to the hollow portion of the hollow shape member
210.
[0053] The upper half of the front end portion 100 is provided with
windows and the like, and the lower front end space thereof stores
equipment for operating the railway car. The lower end of the
plates constituting the side surfaces of the front end portion 100
covers the sides of the upper and lower shock absorbers 200,
200.
[0054] In the underframe 30, side sills (not shown) are provided to
both width-direction-ends of the car body. The side sill is a large
and firm hollow shape member. The front end portion 100 does not
have hollow shape members corresponding to the size of the side
sill. Further, the front end portion 100 does not include a member
having the strength corresponding to that of the hollow shape
member forming the side sill of the underframe 30. A member (not
shown) for connecting the coupler 70 is equipped to the lower
surface of the underframe 30. However, the front end portion 100 is
not equipped with such member. This member is equipped along both
the longitudinal direction and the width direction of the car body.
This member and the hollow shape member constituting the side sill
is strong against the compressive load in the longitudinal
direction of the car body. Moreover, there is also a member for
supporting the coupler 70.
[0055] When the railway car crashes into an obstacle, impact load
occurs. When the coupler 70 collides, the impact causes the coupler
70 to drop off from the car, and causes the shock absorber 200 to
exert its shock absorbing function. When the anticlimber 250
collides, the impact acts on the hollow shape members 210
constituting the shock absorbers 200, 200.
[0056] Since the hollow shape members 210 are soft, they deform
upon receiving impact before deformation of the underframe 30
occurs, thereby relieving the impact. According thereto, the safety
of the passengers is ensured. The impact causes the length of the
hollow shape members 210 to shrink to about half to one-third of
their original length. At such time, the equipment provided above
the hollow shape members 210 is prevented from entering the
driver's cab and harming the driver. This is realized for example
by appropriately designing the position and size of the equipment.
Moreover, a partition wall for separating the equipment and the
driver's cab 80 can be equipped to the frame 110, the upper shock
absorbers 200, 200 and the plate 150, so as to ensure the safety of
the driver. The partition wall can be constituted by the box
enclosing the equipment. The partition wall can be equipped to the
seat 40 and the underframe 30. Moreover, the driver's seat 85 can
be set to a position where it is clear of any equipment that may
enter the driver's cabin upon impact. According to another example,
sufficient space is provided between the seat 85 and the equipment
that may enter the cabin.
[0057] We will now explain the impact-relieving characteristic of
the hollow shape member 120. When compressive load is added
thereto, the hollow shape member shows the load-deformation
behavior as shown in FIG. 10. Three types of material
characteristics is considered as shown in FIG. 11, a material i
having high strength (such as pull strength, yield strength) and
small elongation (brittle), a material iii having less strength but
better elongation, and a material ii having a property intermediate
those of materials i and iii. The material shown by the curve X
(X1, X2) of FIG. 10 (the material corresponding to strength
property i of FIG. 11) has better withstand load, but the withstand
load drops rapidly when the value exceeds the maximum load. On the
other hand, when the material has low strength and high elongation
(the material corresponding to strength property iii of FIG. 11),
the maximum withstand load is smaller but the withstand load does
not rapidly drop after the maximum value, as shown by the curved
line Y of FIG. 10.
[0058] The shaded area shown in FIG. 10 corresponding to curved
line Y indicates the breaking energy of this material. When
comparing the X curve with the Y curve, the material having less
strength and more elongation (in this case, the material of curved
line Y) has higher breaking energy according to the deformation
behavior after exceeding the maximum withstand load. It is
important to select as shock absorbing member B a material having
such strength characteristic Y. A material having the Y-curve
property can be obtained easily by providing an O-material
treatment to an extruded member, for example.
[0059] In case of the curved line X, since the material has high
strength and small elongation, the elongation of the member cannot
correspond to the imbalance of the stress within the cross-section
of the member, causing partial breaking thereof, and reducing the
withstand load rapidly. On the other hand, in the case of the
curved line Y, the maximum withstand load of the member is lower
than the material of the curve X, but since the elongation of the
material is greater, plastic deformation of the material
(elongation of the member) occurs partially corresponding to the
scattered stress within the cross-section of the material,
preventing the withstand load from dropping rapidly. According to
this material, the material can deform greatly while maintaining a
certain level of withstand load.
[0060] When such material is utilized, the hollow shape member 210
deforms into a concertinas (into an accordion-form), relieving the
shock loaded to the car body. Moreover, since a hollow-shape form
is applied, in comparison to the general thin-plate structure, the
member has higher inner-plate and outer-plate flexural rigidity,
and since it has a composite structure including two face plates
and cross (oblique) plates, it has higher breaking-energy
absorption property against the compressive load (per unit planar
area).
[0061] Plural hollow shape members 210, 210 are welded together by
friction stir welding along the longitudinal direction of the car
body in the direction of the impact. If the welding is performed by
arc welding, the weld portion may break during impact and the
members cannot deform into an accordion form, and the energy
absorption characteristic of the members drop. This is because by
arc welding, the impact value of the weld portion is greatly
reduced compared to the impact value of the base material. On the
other hand, the impact value of the friction-stir-welded portion is
higher compared to the arc-weld portion, and the joint will not
break by impact. The reason for this is considered to be that the
metal constitution of the joint is refined by the friction stir
welding, and the energy absorption value is improved. Therefore,
when the hollow shape members are welded by friction stir welding,
each hollow shape member deforms in a desired manner, absorbing the
impact energy.
[0062] Since the shock absorbers 200 are provided in upper and
lower layers, the impact energy can be absorbed by applying
existing hollow shape members.
[0063] The upper and lower hollow shape members 210 are notched in
the form of pillars 120, 130, so as to weld the pillars. According
to this structure, the impact of the collision can be transmitted
effectively to the hollow shape members 210, 210 from the pillars
1200, 130 that collide with an obstacle.
[0064] Since the anticlimber 250 is overlapped with the hollow
shape member 210 by its pipes 256, the anticlimber 250 can transmit
the impact to the hollow shape member 210 even when it collides
slantwise against the obstacle.
[0065] According to the above-mentioned embodiment, friction stir
welding is performed from both sides of the hollow shape member,
but it is also possible to weld the second face plates of two
members from the first face plate side of the members, and then
weld the first face plates via a connecting material, as shown in
FIG. 9 of the above-mentioned Japanese Patent No. 3014654 (EP
079743 A2).
[0066] Now, the shock absorber 400 mounted between the rear end of
the leading car A and the end of a middle car B will be explained.
The shock absorber 400 has a similar composition as the shock
absorber 200. A plate 150 and a support seat 215 is disposed
between and on top of the left and right shock absorbers 200, 200
(400, 400), constituting the floor of the passage for the crew,
etc. An anticlimber 250 is disposed on the front end of the shock
absorber 400. When a shock absorber 400 is disposed also between
the left and right shock absorbers 400, 400, the anticlimber 250 is
mounted to the front end of this shock absorber 400.
[0067] The area above the shock absorbers 400 and the seat 215 can
be the space where the entrance 510 is provided. The area can also
provide space for the switch board (control panel). Moreover, it
can be a space having no passenger seats. Such use of the upper
area of the absorbers 400 enables minimum damage to the passengers
upon collision.
[0068] The end portion 500 comprising the shock absorbers 400 is
removably connected to the car body 90 by bolts, similarly as the
front end portion 100. The front end of the portion 500 is not
curved or protruded as portion 100, but is perpendicular.
[0069] The number of the shock absorbers 400 can be less than the
number of shock absorbers disposed at the front end portion. Since
the energy to be absorbed differs according to the position in the
car body in which the shock absorbers are disposed, the number of
shock absorbers is determined correspondingly. For example, the
shock absorber 400 only has an upper layer. Moreover, the
cross-sectional area of the hollow shape members 210 in the shock
absorber (the area composed of the cross-sectional area of the face
plates 211, 212 and the connecting plates 213, 215) is varied
according to position. The shock absorbers equipped to the middle
cars disposed near the center of the railway car comprises smaller
number of members and smaller cross-sectional areas compared to the
shock absorber 200 equipped at the front end 100. The above
explains the relation between the leading car and the middle car,
but even when comparing the shock absorbers 500 of the middle cars,
the shock absorber 500 disposed to the middle car near the center
of the railway car body has smaller number of members and smaller
cross-sectional area compared to the middle car 500 disposed near
the end of the railway car body.
[0070] There is no member for connecting the coupler 70 disposed on
the end portion 500, similar to the front end portion 100. Upon
collision, the coupler 70 drops off so that the shock absorber 400
exerts its shock absorbing function. Moreover, the end portion 500
is not equipped with a strengthening member corresponding to the
hollow shape member constituting the side sill of the underframe
30. The lower end of the plates constituting the outer sides of the
end portion 500 covers the sides of the shock absorber 400.
However, the area of the end portion 500 receiving load, from the
entrance 510 and the like, is equipped with members for supporting
this load at the floor. This member collapses simultaneously as
when the shock absorbers 400 collapse. The floor of the passenger
entrance 510 and the like is supported by the shock absorbers
400.
[0071] The end portion 500 can include soft side sills. Such soft
side sills can be formed by annealing or punching appropriate holes
thereto. The front end portion 100 and the end portion 500 are
formed separately from the car body 90 in the above embodiment, but
they can also be formed integrally with the car body 90. The hollow
shape members 210 can be softened by providing holes thereto at
predetermined intervals, or by selecting an appropriate plate
thickness. Moreover, the construction of a common conventional
shock absorber can be applied to the shock absorber of the present
invention.
[0072] The technical scope of the present invention is not
restricted to the language used in the claims or in the summary of
the present invention, but is extended to the range in which a
person skilled in the art could easily substitute based on the
present disclosure.
[0073] The present invention enables to provide a railway car that
ensures safety by absorbing the impact energy upon collision.
* * * * *