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EP-3865371-B1 - APPARATUS AND METHOD FOR MOVING THE POINT BLADES OF A RAILROAD SWITCH

EP3865371B1EP 3865371 B1EP3865371 B1EP 3865371B1EP-3865371-B1

Inventors

  • BIAGIOTTI, MAURIZIO
  • BECCARISI, Alessandro

Dates

Publication Date
20260506
Application Date
20210205

Claims (15)

  1. Apparatus (1) for moving the point blades of a railroad switch (500) comprising: - at least a hydraulic actuator (71) comprising a first and a second push chamber (77,78); - a displacement group (20) configured to translate along a displacement direction (120) in a first displacement direction, or in a second displacement direction opposite to the first, in such a way to move, alternately, at least a point blade (101,102) between two limit positions in which the point blade is, respectively, closed to, or spaced from, a respective rail stock (111,112), said displacement group (20) being caused to translate along said displacement direction (120) in said first, or second, displacement direction, according to the pressure applied by a working fluid in said first, or second, push chamber (77,78); - a feeding group (200) comprising a pumping device (205) configured to feed a first predetermined constant flow of said working fluid into a main feeding circuit (210), said feeding group (200) being, furthermore, configured to feed at least a second determined flow of said working fluid into said first, or second push chamber (77,78) of said, or each, hydraulic actuator (71), through a respective peripheral feeding circuit (215) comprising: - a first control branch (201) hydraulically connected to said first push chamber (77), said first control branch (201) being provided with a first flow measurement device (211) configured to constantly detect flow data in said first control branch (201), and a first pressure measurement device (221) configured to constantly detect pressure data in said first control branch (201); - a second control branch (202) hydraulically connected to said second push chamber (78), said second control branch (202) being provided with a second flow measurement device (212) configured to constantly detect flow data in said second control branch (202), and a second pressure measurement device (222) configured to constantly detect pressure data in said second control branch (202); said feeding group (200) comprising, furthermore, at least a servo valve (250) arranged to hydraulically connect said main feeding circuit (210) with a respective peripheral feeding circuit (215), said, or each, servo valve (250) being configured to adjust said flow and said pressure of said working fluid in said respective peripheral feeding circuit (215); said apparatus (1) being characterized in that it, furthermore, provides a control group (300) comprising: - a main processing unit (350) operatively connected to said pumping device (205) and configured to set a predetermined flow trend and a predetermined pressure trend for said, or each, peripheral feeding circuit (215) ; - at least a peripheral processing unit (400) operatively connected to said main processing unit (350), to a respective servo valve (250), to said respective first and second flow measurement devices (211,212) and to said respective first and second pressure measurement devices (221,222), said, or each, peripheral processing unit (400) being configured to operate said respective servo valve (250) in such a way to adjust the flow and the pressure in said respective peripheral feeding circuit in order to obtain respectively a flow trend and a pressure trend of said working fluid that is set by said main processing unit (350), and to send to said main processing unit (350) said flow and pressure data detected in said respective peripheral feeding circuit (215) by said flow measurement devices (211,212) and by said pressure measurement devices (221,222), said main processing unit (350) being configured to process said received flow and pressure data and to verify that said respective flow and pressure trends correspond or not to said predetermined flow and pressure trends.
  2. Apparatus for moving the point blades of a railroad switch, according to claim 1 wherein if said detected flow and pressure trends and said predetermined flow and pressure trends does not coincide with each other, or their difference is greater than a predetermined threshold value, said main processing unit (350) is arranged to command at least a peripheral processing unit (400) to operate said respective servo valve (250) in such a way to increase, or decrease, said flow and/or said pressure of said working fluid in the respective peripheral feeding circuit (215).
  3. Apparatus for moving the point blades of a railroad switch, according to claim 1, or 2, wherein each said first and second flow measurement device (211,212) is an ultrasonic flow measurement device.
  4. Apparatus for moving the point blades of a railroad switch according to any of the previous claims wherein a plurality of hydraulic actuators (71a-71c) is provided, and wherein said main processing unit (350) is configured to command said plurality of peripheral processing units (400a-400c) to operate a respective plurality of servo valves (250a-250c), in such a way to feed into said respective peripheral hydraulic circuit (215a-215c) a respective flow of said working fluid at a respective pressure in order to synchronously move said plurality of hydraulic actuators (71a-71c).
  5. Apparatus for moving the point blades of a railroad switch, according to any of the previous claims wherein said main processing unit (350) is configured to command said, or each, peripheral processing unit (400a-400c) to operate a respective servo valve (250a-250c) in such a way to reduce the pressure in said respective peripheral feeding circuit (215a-215c) from a starting pressure (p2a-p2c) up to reach a predetermined final value (p2*a-p2*c), starting from a predetermined position of the respective hydraulic actuator (71a-71c), in such a way to correspondingly reduce the pushing force (Fa-Fc) applied by said, or each, hydraulic actuator (71a-71c) up to reach a predetermined value (Fa*-Fc*) thus avoiding a further stroke of the same if an external force is present that is greater than said reduced pushing force.
  6. Apparatus for moving the point blades of a railroad switch, according to claim 5, wherein said main processing unit (350) is configured to command said, or each, peripheral processing unit (400a-400c) to operate said respective servo valve (250a-250c) in such a way to start to reduce said starting pressure (p2a-p2c) when said point blade (101,102) is positioned at a distance (d) from the respective rail stock (111,112) that is less than a predetermined distance (d*), thus reducing said pressure of said working fluid up to reach said predetermined value (p2*a-p2*c) only in proximity of said limit position.
  7. Apparatus for moving the point blades of a railroad switch, according to claim 6, wherein said distance of said point blade (101,102) from said respective rail stock (111,112) is determined by said main processing unit (350) according to said flow data detected by said first, or second, flow measurement device (211a-211c;212a-212c) and sent to said main processing unit (350) by said, or each, respective peripheral processing unit (400a-400c).
  8. Apparatus for moving the point blades of a railroad switch, according to any of the previous claims wherein a manual operating group (600) is, furthermore, provided configured, when is manually operated, to bypass said pumping device (205) in case of emergency, and to operate an auxiliary pumping device (206).
  9. Apparatus for moving the point blades of a railroad switch, according to claim 8 wherein said auxiliary pumping device (206) is hydraulically connected to said first and second pushing chambers (77,78) of at least a hydraulic actuator (71) through a supplementary feeding circuit (210').
  10. Apparatus for moving the point blades of a railroad switch, according to claim 9 wherein said supplementary feeding circuit (210') comprises at least a first sequence valve (216) installed along a respective first control branch (201), and a second sequence valve (217) installed along a respective second control branch (202), said, or each, first and said, or each, second sequence valve (216,217) being configured to feed said working fluid into said respective first, or second, push chamber (77,78) of said respective hydraulic actuator (71).
  11. Apparatus for moving the point blades of a railroad switch, according to any of the previous claims wherein each peripheral processing unit (400) is installed at a predetermined distance (D) from said respective hydraulic actuator (71) that is less than, or equal to 8 m.
  12. Apparatus for moving the point blades of a railroad switch, according to any of the previous claims wherein each peripheral processing unit (400) is installed at a predetermined distance (D) from said respective hydraulic actuator (71) that is less than, or equal to 5 m.
  13. Apparatus for moving the point blades of a railroad switch, according to any of the previous claims wherein each peripheral processing unit (400) is installed at a predetermined distance (D) from said respective hydraulic actuator (71) that is less than, or equal to 2 m.
  14. Apparatus for moving the point blades of a railroad switch, according to any of the previous claims wherein said first and second push chambers (77,78) are the opposite chambers of the same double acting hydraulic actuator, or the respective chambers of a first and a second single acting hydraulic actuator.
  15. Method for moving the point blades of a railroad switch comprising the steps of: - translating along a displacement direction in a first displacement direction, or in a second displacement direction opposite to the first, a displacement group in such a way to move, alternately, at least a point blade between two limit positions in which the point blade is, respectively, closed to, or spaced from, a respective rail stock, said displacement group being caused to translate along said displacement direction in said first, or second, displacement direction, depending on the pressure applied by a working fluid in a first, or in a second push chamber, defined in at least a hydraulic actuator; - feeding a first predetermined flow of said working fluid into a main feeding circuit and at least a determined second flow of said working fluid into said first, or second push chamber of said, or each, hydraulic actuator, through a respective peripheral feeding circuit comprising a first control branch hydraulically connected to said first push chamber and a second control branch hydraulically connected to said second push chamber; - setting a predetermined flow trend and a predetermined pressure trend for said, or each, peripheral feeding circuit by a main processing unit; - adjusting said, or each, determined second flow and pressure of said working fluid in said, or each, respective peripheral feeding circuit by at least a respective servo valve arranged to hydraulically connect said main feeding circuit with a respective peripheral feeding circuit, said adjusting step being carried out by operating said, or each, servo valve by a respective peripheral processing unit operatively connected to said main processing unit and said servo valve; - detecting flow and pressure data in said first control branch and in said second control branch; - sending said detected flow and pressure data to said peripheral processing unit; - sending said flow and pressure data detected by said peripheral processing unit to said main processing unit; - processing by said main processing unit said received flow and pressure data to verify if the corresponding flow and pressure trends of said, or each, peripheral feeding circuit correspond, respectively, to said predetermined flow and pressure trends.

Description

Field of the invention The present invention relates to the railway technical field and in particular it relates to an apparatus for moving the point blades of a railroad switch, in particular of the type used in high-speed rail. Description of the prior art As known, the apparatuses used for moving the point blades of a railroad switch generally provide at least one shifting actuator which moves, by movement transmission means, the point blades of the railroad switch between two limit positions. More precisely, at the aforementioned limit positions, a point blade is closed to the respective rail stock and is, therefore, called closed point blade, whilst the other point blade is far removed from the respective rail stock and is, therefore, called open point blade. At the opposite limit position, instead, the opposite situation occurs, and, therefore, the point blade that in the previous limit position was the closed point blade is positioned at a predetermined distance from the respective rail stock and therefore it becomes the open point blade, whilst the point blade that previously was the open point blade is arranged closed to the respective rail stock and, therefore, becomes the closed point blade. The movement from a limit position to the other is caused, as anticipated above, by an actuator, for example a hydraulic actuator which has a predetermined actuation stroke along an actuation direction. The switch machines of known type, furthermore, provide locking/unlocking devices, which provide the so called switch point locking means that block the point blades in one of the above disclosed limit positions. Normally, the switch point locking means are arranged from an unblocking configuration to a blocking configuration through an over-stroke of the actuator along the actuation direction known as overlapping. A situation which can occur in the railway switches is that an obstacle, for example a stone, can interpose between the point blade and the rail stock, thus impeding the correct displacement of the railway switch, and in particular to move the point blade closed to the respective rail stock. This situation could cause the control to signal that the railroad switch is in the correct position even if the point blade is bent due to the object that is present between the point blade and the rail stock. This situation is potentially dangerous, in particular in high-speed railway lines, because the train could run on a railroad switch that is not arranged in the correct geometry. In light of the above, the apparatuses of prior art for displacing the point blades of the railroad switches are not able to satisfy the necessary safety requirements. An example of a system for displacing the point blades of a switch machine with the aforementioned drawbacks is described in EP3409561. Summary of the invention It is, therefore, an object of the present invention to provide an apparatus for moving the point blades of a railroad switch that is able to overcome the aforementioned drawbacks of the prior art apparatuses. It is a particular object of the present invention to provide an apparatus for moving the point blades of a railroad switch that is easy to be installed and that is able to assure that the point blades can be moved highly accurately. It is another object of the present invention to provide an apparatus for moving the point blades of a railroad switch that is able to assure a high safety level for the passengers and the trains running the corresponding stretch of the railway line. It is still another object of the present invention to provide an apparatus for moving the point blades of a railroad switch that is able to quickly and accurately detect if an obstacle is present between the point blade and the rail stock. It is also an object of the present invention to provide an apparatus that allows to control both each component and the whole system, communicating any anomaly, or deviation from the optimal functioning. It is a further object of the present invention to provide a method for moving the point blades of a railroad switch having the same advantages. These and other objects are achieved by an apparatus for moving the point blades of a railroad switch comprising: at least a hydraulic actuator comprising a first and a second push chamber;a displacement group configured to translate along a displacement direction in a first displacement direction, or in a second displacement direction opposite to the first, in such a way to, alternately, move at least a point blade between two limit positions in which the point blade is, respectively, closed to, or spaced from, a respective rail stock, said displacement group being caused to translate along said displacement direction in said first, or second, displacement direction, according to the pressure applied by a working fluid in said first, or second, push chamber;a feeding group comprising a pumping device configured to feed a predetermined first flow