Note: Descriptions are shown in the official language in which they were submitted.
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~ACKGROUND OF THR INVENTION
1~ Field of the Inventiorl
This invention relates to a pendulum vehicle, and in
partiular to structures for a railway vehicle having
pendulum function.
2. Description of the Prior Art
An example of a typical prior art is disclosed in
Japanese Patent Laid-Open Showa 59-143760. In the prior
art, on a truck frame is provided a rotating beam which
can rotate about the axis of a center pin. On the rotat-
ing beam is mounted a swing bolster by means of rollers
arranged at both ends of the beam. Further, on the swing
beam is supported a vehicle body by air springs.
In the prior art described above, the pendulum
vehicle is provided with the rollers and the swing bol-
ster, which makes the structure of the vehicle compara-
tively complicated, resulting in worrisome maintenance
work. Further, the structure with dusttight and dipproof
functions is required for the rollers, which also brings
about worrisome maintenance work.
SUMMARY OF THE INVENTION
It is therefore the object of the present invention
to provide a pendulum vehicle in which the structure and
the maintenance work are simplified, and comfortable
drive is guaranteed.
A pendulum vehicle according to the present inven-
tion comprises: a vehicle body; a plurality of trucks
each having a truck frame provided below the vehicle
~048~8 :3
body; and a pair of transversely arranged resilient mem-
bers provided o~ the truck frame for supporting the
vehicle body; wherein axes of the resilient n~embers tilt
so as to approach each other as height rises, and uncou-
ple point, which is defined as a point where the vehicle
body does not tilt but moves only horizontally in case
that transverse load is applied to the point on the
vehicle, is arranged at the position higher than the
center of gravity of the vehicle.
When transverse load is applied to the point higher
than the uncouple point, the portion on the vehicle
which is higher than the uncouple point will tilt
with displacement larger than the displacement at the
uncouple point. On the other hand, when the transverse
load is applied to the point lower than the uncouple
point, the portion on the vehicle which is lower than the
uncouple point will tilt with displacement larger
than the displacement at the uncouple point.
In the present invention, on the truck frame sup-
porting wheel axles is supported a vehicle body by means
of resilient members such as air springs. The axles of
the resilient members tilt so as to approach each other
as height rises. Therefore, the point where the axles of
the resilient members and the axle of the vehicle cross
each other is positioned over the truck frame and the
uncouple point is also formed over the truck frame.
In the present invention, since the uncouple point
is designed so as to be positioned higher than the center
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of gravity of the vehicl.e body when transverse load
because of centrifugal t`orce is appl.ied to the center of
gravity of the vehicle body when passing -through curves,
the portion of the vehicle body which is lower than the
uncouple point moves with displacement larger than
the displacement at the uncouple point, causing the
vehicle body to tilt inwardly, which permits pendulum
function of the vehicle.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be more apparent from the
ensuring description with reference to the accompanying
drawing wherein:
Figure 1 is a plan view showing one embodiment of
the present invention;
Figure 2 is a side view showing the emhodiment of
Fig. 1;
Figure 3 is a front view of the truck 2;
Figure 4 shows ~he cross section taken along the
line IV-IV of Fig. 2;
Figure 5 shows the cross section adjacent to the
wheel lOa;
Figure 6 is a diagrammatic illustration showing the
configuration of the air springs 9;
Figures 7A and 7B are drawings to explain spring
constants of the air springs 9;
Figure 8 is a drawing briefly illustrating the
structure of the air springs 9; and
Figure 9 is a drawing briefly showing the structure
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of the resilien~ member 9a accoIding to another embod-i-
ment of the present invention.
DETAII.ED DESCRIPTION OF PRE~ERR~t~ EMBODIMENTS
A prererred embodiment o~ a perldu1ulll vehicle accord-
ing to the present invention will now be described with
reference to drawings.
Figure 1 is a plan view of the pendulum vehicle
according to one embodiment of -the present invention and
Fig.2 is a side view of the vehicle. In a railway vehi-
cle in accordance with the present invention, a vehicle
body 1 is supported by a pair of two-axle trucks 2 ar-
ranged at both ends of the vehicle. Between a pair of
rails 3 along a service route on the ground is provided
reaction plates constituting a linear motor. On the
truck 2 is mounted coils 5 opposing to the reaction
plates to get propulsion. Over the rails 3 is arranged a
substantially H-shaped truck frame 6. Adjacent to a
lateral mid-portion of side beams 7 of the truck frame 6
is installed air springs 9 as a pair of transversely
arranged resilient members through supporting members 8,
which support the vehicle body 1.
Figure 3 is a front view of the truck 2 and Fig. 4
shows a cross-section taken along the line IV-IV of Fig.
2. Figure 5 shows a cross-section of the portion adja-
cent to wheels lOa. The wheels 10a are fixed to axles
11, which are supported on bearings 12 in cylindrical
bearing hoxes 13a adjacent to the wheels 10a. At the
axial mid-portion of the bearing body 13a is formed a
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shaft 1~a projecting upward. The sha~t 1~a is rotatably
mounted in a supporting hole 16 which is formed on a
mountin~ member 15. To the mounting member 16 i~ fixed
the reaction plate 5. The side beam 7 of the truck frame
6 is supported by abrasion plate or resilient member 17a
such as springs which is positioned between the beam and
the bearing box 13a in the vicinity of the bearing 12.
Another wheel 10b has the same structure as the wheel 10a
and the portions of the wheel lOb corresponding to those
of the wheel 10a are described by the same reference
number with a subscript b. Propulsion, which is applied
to the coil 5 on the vehicle, is transmitted to the truck
frame 6 via a propulsion transmitting means 18, and is
further transmitted to the vehicle body 1 via a propul-
sion transmitting link device 50. The propulsion trans-
mitting link device 50 comprises links 19a and l9b, a
tracking beam 20, and a center pin 21. When the vehicle
body does not move laterally, vertical axis of the center
pin 21 substantially corresponds to the center of the
truck. At both ends of the link l9a are arranged spheri-
cal bearings or resilient members. One end of the link
l9a is rotatably connected to a front side-beam 6a and
the other end is to the right side of the tracking beam
20 of the truck frame 6 by means of spherical bearings or
resilient members. One end of the link l9b is also
rotatably connected to a rear side-beam 6b and the other
end is to the left side of the tracking beam 20 of the
truck frame in the same manner as the link l9a. Both
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].inks l9a ~nd 19b are arran8ed so as to be parallel to
each other. The center pin 21, which is posi.tioned at
the middle of the links t9a and l9b arranged at both ends
the tracking beam 20, rotatably connects the vehi.cle body
1 to the tracking beam 20 about the vertical axis 23 of
the center pin 21.
By virtue of the propulsion transmitting link device
50 of the structure described above, propulsion, braking
force or the like is transmitted in the longitudinal
direction between the vehicle body 1 and truck frame 6
while permitting relative transverse disposition and
rotation between them.
Figure 6 is a diagrammatic illustration showing the
arrangement of the air springs 9 and others. The axes 26
of the pair of air springs 9 tilt in the same vertical
plane so that the axes approach to each other to cross at
intersection 27 as height rises under the condition that
the vehicle passes through horizontally liner truck.
This intersection 27 is the geometrical center of the air
spring in the direction of the axis of the air spring.
The center of gravity of the vehicle body is located in
the vicinity of the perpendicular bisector 29 of the line
28 passing through the centers of the pair of air springs
9. The uncouple point 30, which corresponds to the
center of oscillation of this pendulum vehicle, is on the
perpendicular bisector 29. Even when load P as a trans-
verse load is applied to the uncouple poi.nt 30, the
vehicle body 1 moves only horizontally and does not tilt.
2 ~ '3
This transverxe Load comprises centrifugal force and the
like, which acts ~n a vehicle when passi.ng through
curves. Tn the present invention, the uncouple point is
designed so as to be higher than the center of gravity of
the vehicle body 1.
Referring to Figs. 7A and 7B, where spring constant
of the air spring 9 in the direction of the axis 26 is
defined as Kr and that of the spring 9 in the direction
perpendicular to the axis 26 is defined as Kl, and fur-
ther, spring constant of the air spring 9 in the direc-
tion parallel to the perpendicular bisector 29 is deter-
mined as Kx and that of the spring in the direction
parallel to the line 28 is Ky, the following formula
holds. In the formula, the distance between the line 28
and the intersection 27 is H1; the distance between the
centers of the pair of air springs is 2B; and the angle
between the axis 26 and the perpendicular bisector 29
is ~.
H 1 = B / t a n a (1 )
K x = K r c o s2a + K 1 s i n2a . . . (2 )
K y = K r s i n2a + K 1 c o s2a (3 )
Therefore, the height C of the uncouple point
30, that is, the distance between the point 30 and the
line 28 is determined by formula 4.
K 1
~ c o t a
C = - K r B ~ ~ (4 )
K 1 2
1 + c o t a
K r
The spring constant Kx described above is determined
so as to have around 1 Hz of characteristic frequency of
the vehicle body, as an example. The transverse sprin~
constant Kl of the air spring 9 is selected so as to be
comparatively small. Further, the axial spring constant
Kr is determined in such a manner that the spring con-
stant Kx as described above is to be obtained.
As shown in Fig. 8, the air spring 9 described above
is realized with the structure in which a pair of sub-
stantially flat suppor-ting plates 32 and 33 are provided
on upper and lower surfaces of air-filled bag 31 with
resiliency by rubber or the like, and auxiliary air
chamber 36. The structure permits the air spring 9 to
have the axial spring constant Kr and the transverse
spring constant Kl thereof with the following relation
with ease.
Kr > Kl . . ~(5)
The transverse load because of the centrifugal force
described above acts on the center of gravity of the
vehicle body 1. Since the uncouple point is posi-
tioned higher than the center of gravity of the vehicle
body 1, when transverse load acts on the vehicle when
passing through curves, the vehicle body tilts inwardly
with respect to the uncouple point 30, which can
reduce transverse acceleration felt by passengers by the
pendu]um function.
As another embodiment ot` the present inventiorl,
springs 9a may be used in place of the air sprirlgs 9a.
The springs 9a are formed by accumulating a plurality of
resilient pieces 34 made of thin rubber or the like and
interposing stiff flat plates 35 such as steel plates
each between the resilient pieces.
Other structure may be applied to attain the object
instead of the air springs 9 and the resilient members
shown in Fig. 9.
In the present invention as described above, since a
pair of transversely arranged resilient members, of which
axes tilt so as to approach each other as height rises,
support a vehicle body on a truck frame and uncouple
point formed by the above structure is designed in such a
manner as to be higher than the center of gravity of the
vehicle body, pendulum function of the vehicle body is
obtained without rollers and a swing bolster disclosed in
the prior art. Therefore, the s-tructure and maintenance
work are simplified. Further, stationary transverse
acceleration felt by passengers when passing through
curves can be reduced to achieve comfortable drive, which
improves the vehicle speed on a curved track.
