Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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BACKGROUND OF THE INVENTION
This invention relates to an upgrade speed
control system for a railway marshalling yard.
Conventional railway marshalling yards have a
single hump with a downgrade at the end of the yard.
The hump height of a conventional marshalling
yard is selected according to the running characteristics
of poorer running cars under difficult conditions. In
other words, the hump height must be high enough to ensure
that the poorer running cars can run to the end of the
yard and couple safely with the standing cars. In routine
operations, however, most of running cars or cuts have
medium running characteristics, the poorer and better
running cars forming but a small proportion. Consequently,
the hump height designed for poorer running cars has caused
the following problems. For instance, the hump height
is increased for only a few poorer running cars, but the
potential energy of the whole train is also increased,
so the speeds of most medium and better running cars are
very high at the time of entering sorting sidings, which
leads to the use of additional speed control devices to
reduce the cars' speed by offsetting the excess energy
obtained from the hump. Moreover, in the case of breaking,
additional energy would also be consumed by additional
speed means.
With the increase of the hump height, there
should also be an increase in the elevation level of the
reception yard. This results in a considerable increase
in the earthwork of the reception yard, a much larger
investment and a longer construction period as well.
An object of the present invention is to
overcome the above-discussed shortcomings of the profile
of the conventional railway marshalling yard.
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SUMMARY OF THE INVENTION
An upgrade speed control system according to
-this invention is quite different from the conventional
marshalling yard profile and speed control system. Pur-
suant to the invention, a railway marshalling yard is
provided with an upgrade speed con-trol section and a
corresponding number of boosters and retarders for the
profile of a downgrade marshalling yard so as to form an
upgrade speed regulating unit; at least one such unit is
combined with the main hump of the marshalling yard to
form an upgrade speed control system. The height between
the crest of the main hump and the crest of the sub-hump
is designed according to the running characteristics of
medium running cars. Some boosters are provided to re-
plenish energy for only a few poorer running cars or cuts
while some retarders are needed to realize braking for
a few better running cars or cuts. Thus, the speed of
both poorer and better running cars or cuts will approximate
the speed curve of moderate or average running cars or
cuts.
If an upgrade speed control system of a mar-
shalling yard with one upgrade unit is used in at least
one place of humping or retarding or coupling area, the
feature of each area could be:
1. When the upgrade speed control system with one upgrade
speed control unit is used in the humping area, the
boosters and retarders installed on the upgrade speed
control unit are controlled by computer in accordance
with the weight, axle number and speed of cars or
cuts, thus making the upgrade speed control unit a
tool to realize interspacing braking and to restore
the initial time difference between poorer and better
running cars or cuts at the crest. As a result, the
interspacing between the cars or cuts is adjusted.
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2. When an upgrade speed control system with one upgrade
speed control unit is used in the retarding area,
boosters and retarders installed in the upgrade speed
control unit are controlled by computer in accordance
with the weight, axle number and speed of cars or
euts, thus making the upgrade speed control unit a
tool for applying objeetive braking to medium and
better running ears or euts. In this way, the medium
running cars can reach the specified coupling speed
without the functioning of boosters and retarders,
the better running ears or cuts can also reach the
specified eoupling speed with the funetioning of
retarders; and the poorer running cars and long cuts
can quiekly pass through various shunting switches
with the functioning of boosters.
3. When an upgrade speed eontrol system with one upgrade
speed eontrol unit is used in the coupling area
the upgrade speed control unit forms anenergy reser-
voir which converts the power produeed by booster
meehanisms into potenti~l energy of car cuts and
reserves the energy, thus extending the coasting
distance of car cuts.
More specifically, according to the invention,
there is provided, in a railway marshalling yard, a speed
control system comprising:
primary acceleration means for providing a
predeterminable initial speed to a running car to be
sorted, said primary acceleration means including a main
hump over which a railway track guiding said running car
extends;
firstdeceleration means for decreasing a velo-
eity of said running ear upon aeeeleration of said running
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car to said initial speed, said first deceleration means
including at least one subhump over which said railway
track extends downgrade of said main hump, said subhump
having a height differing from a height of said main hump
in accordance with running characteristics of an average
railway car;
control means for determining acceleration and
deceleration characteristics of said running car, said
control means including velocity and weight sensors dis-
0 posed alongside said railway track at said subhump;second deceleration means including a retarding
mechanism operatively coupled to said control means for
additionally decreasing, under the control of said control
means, the velocity of said running car upon a determi-
nation by said control means that said running car hasbetter running characteristics, said second deceleration
means being disposed downgrade of said subhump; and
secondary acceleration means including a
booster mechanism operatively coupled to said control
means for accelerating, under the control of said control
means, said running car upon a determination by said con-
trol means that said running car has poorer running cha-
racteristics, said secondary acceleration means being
disposed downgrade of said main hump.
The objects, advantages and other features
of the present invention will become more apparent upon
reading of the following non restrictive description of
preferred embodi.ments thereof, made in connection with the
accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a diagram of an upgrade speed control
unit according to the present invention;
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Fig. 2 is a diagram, in profile view, of an
upgrade speed control system with several upgrade speed
control units according to the invention; and
Fig. 3 is a diagram of a marshalling yard with
a retarding area provided with an upgrade speed control
unit.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
As illustrated in Fig. 1, an upgrade speed
control unit includes speed-measuring pedals 1, a track
circuit 2, an electropneumatic valve 3, a process control
computer 4, a booster 5 and a retarder 6, both the booster
and retarder being components controlled by the control
computer.
Fig. 2 is a profile view of an upgrade speed con-
trol system with respective upgrade units provided for a swit-
ching area 1, a retarding area 2 and coupling area 3.
The drawing shows that depressed profiles
ABlB, BClC and CDlD are formed in humping area 1,
retarding area 2 and coupling area 3 respectively, because
of the existence of upgrades BlB, ClC and DlD, thus creating
a wave-like profile where downgrades and upgrades are
interconnected instead of a downgrade profile only. The
profile is designed on the following principles:
1. The hump height H is designed according to the ope-
rational conditions of average or medium running
cars, i.e. the height should be so designed that
medium running cars can reach the specified coupling
speed Vs when they arrive at point C after being
humped at the velocity VO from point A on the crest
in winter's head wind. The calculation formula for
height H is:
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V2 ~ V2
AC 2gz ACWz + 6~AC + 24NAC)10 + LA WW 10-3
where:
gz is the acceleration of medium running cars affected
by their rotational inertia,
C is the sum of degrees of turning angles of curves in
Section AC,
NAC is the number of switches in Section AC,
wzw is the basic resistance to medium running cars in
winter,
WFWBc is the wind resistance to medium running cars in winter
(Section BC), and
FBC = 0-063KF ~ max + Vs) 0.5 + ~ ~2
Q2
where:
Vm x is the maximum allowable speed in humping section,
Vs is the allowable coupling speed of cuts,
Vf is the calculated wind velocity,
Q2 is the total weight of medium running cars.
2 The height HAB of point B of upgrade section BlB
should be so designed that medium running cars could
still maintain the minimum allowable speed Vmin in
the humping area when they arrive at point B after
being humped at a speed VO from point A on crest in
winter's head wind.
3. The depressed proEile ABlB should be so designed that
the time diEference between better and poorer running cars
in arriving a-t point B is the smallest, after these
cars are humped at the speed V from point A on the
crest in winter's head wind.
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4. The depressed profile BClC should be so designed thatthe
time difference between better and poorer running cars
in arriving at point Cl is the smallest, after these
cars roll down from point B at their respective initial
speeds VN and VyB in winter's head wind.
5. The height HAD of point D of upgrade section DlD is
determined by the basic resistance to the moderate
running cars. The height difference between point
D and the elevation level of the yard end should be
able to ensure that medium running cars can coast
from point D to the end of the yard.
In an upgrade speed control system with one
upgrade unit for each area, each upgrade speed control
unit is equipped with a certain number of boosters and
retarders in accordance with its own need.
In general, an upgrade speed control system
pursuant to the invention, has the following advantages:
l. The upgrade speed control system is used mainly to
control the speed of most medium running cars, ensuring
the safe operation of a few poorer and better running
cars. Consequently, the hump height is determined in
accordance with the operational conditions of the
medium running cars. i.e. the speed curve of the
medium running cars is taken as a control reference
line, to which the speed curves of poorer and better
running cars should come near. As a result, the hump
height could be lowered, the investment in earthwork
could be reduced remarkably and speed regulation
range of cars can be narrowed.
2. The upgrade speed control system is not designed
using the conventional method of the profiling of a
marshalling yard. According to the conventional design,
the profile is provided with downgrade only and necessary
level section(s) could only work as a natural accele-
rator for cars. The invention works to provide an
upgrade section for the conventional downgrade only
profile, making the section a natural retarder of cars
and making other speed control devices auxiliaries only.
In this way, the speed reduction of cuts would be rea-
lized mainly by the upgrade section instead o~ speed
control devices. Therefore the investment in speed
reducing equipment can be reduced.
3. The upgrade unit converts the excess energy of cuts
into potential energy by use of coupling. This could
extend the coasting distance of cuts, thus solving
the problem of the insufficient potential energy of the
hump of the existing yard and realizing rational use
of the excess energy of cuts.
4. The braking performance produced by the upgrade section
is of gravity type, which has the same braking effect
on both loaded and unloaded cars. Unlike retarders
which suddenly change the running speed of cars, the
upgrade section could reduce the running speed of cuts
gradually in a relatively long distance, thus extending
the service life of railway cars.
The above-mentioned advantages have been proved
by the actual application of the upgrade speed control
system. According to the initial estimate, to realize the
marshalling automation, a marshalling yard with the upgrade
speed control system of the invention can save 30~ of equip-
ment cost as compared with a marshalling yard employing
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another speed control system.
Modifying an existing marshalling yard by
adopting an upgrade speed eontrol system according to the
present invention eould realize marshalling automation,
increasing hump operating capacity and the safe coupling
rate with the minimum investment and at the shortest cons-
truction period. The application of the upgrade speed
control system of the invention in a new marshalling yard
eould lower the hump height and the level of the reception
yard, reauce the number of speed eontrol devices, and in-
erease the hump operating eapacity and safety coupling rate
with the cost eonsiderably redueed.
Fig. 3 shows an example of a marshalling yard
with an upgrade unit pursuant to the invention in the
retarding area, ineluding a weight measuring deviee 1 for
measuring weight and eounting axle of euts, radar antennas 2,
a speed measuring pedal 3, a traek eireuit 4 for transmis-
sion of reliable information relating to cuts before their
arrival at the upgrade section, an eleetropneumatic valve
5 for controlling the air supply of the sealed, eircular
air pipe line, a switeh operating indieator 6, a retarder
eonsole 7 for interval braking, used for changing to manual
operation in the ease of equipment trouble, and a process
control eomputer 8 which controls not only the upgrade
speed control unit in the retarding area, but also the
retarder for interspace braking. This is an example of
modifying an existing marshalling yard by employing an
upgrade unit aecording to the present invention in the
retarding area of the yard and by combining the unit with
the existing speed control devices in the yard. The
operating procedures in such a modified marshalling yard
are described hereunder. When the cuts roll down from
the crest, the weight measuring device will first measure
their weights and count axles. Then, the average weight
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of cuts is determined and sent into the computer as a con-
trol parameter. When the cuts reach the retarder for
interval braking, the retarder realizes interspace braking
of cuts in accordance with the computer's instruction.
When the radar detects that the cuts have the specified
outlet speed of cuts, the retarder releases the cuts.
Before the cuts reach the upgrade speed control unit, the
computer will send instructions to the electropneumatic
valve according to the obtained information about weight,
axle number and speed of cuts. Normally there are three
cases:
1. If the entering cuts are better running, the boosters
are not activated. Only the retarder reduces the speed
of cuts to the specified coupling speed and then releases
the cuts to roll out from the upgrade speed control
unit;
~. If the entering cuts are medium running, the boosters
are activated. The retarder does not function basi-
cally. The cuts will roll out from the upgrade speed
control unit by keeping the specified coupling speed;
and
3. If the entering cuts are poorer running, the boosters
are activated and the retarder does not function basi-
cally. The cuts would be given the specified coupling
speed and roll out from the upgrade speed control unit.
