ELECTROPNEUMATICALLY CONTROLLED CONTROL OF A POWER CONSUMER

Description

[0001] Electropneumatically controlled control of a pantograph The invention relates to a device for controlling a contact force of a pantograph of a vehicle (for example, a locomotive) against an overhead line, a method using such a device, and a vehicle with such a device.

[0002] Pantographs of electric traction vehicles require a defined contact force against the overhead contact line. In this case, the overhead contact line is either a conventional or innovative design, such as ceiling-mounted conductor rails.

[0003] If this contact force is too low, the pantograph will start to jump. The resulting contact interruptions and arcing reduce the service life of the pantograph contact strips and overhead contact lines. If this contact force is too high, the overhead contact line is lifted excessively. With impermissible force applied to the overhead contact line, its mechanical positioning cannot be guaranteed; the pantograph "threading" into the contact and the overhead contact line being pulled down are typical consequences.

[0004] The required contact forces, especially during high-speed operation (>200 km / h), increase sharply to approximately twice the standstill value, as shown in Fig. 1 As shown. To ensure this increase, current-state technology employs wind deflectors in the pantograph, which both generate an additional aerodynamic force and compensate for dynamic lift forces. A disadvantage of this approach is that the design and handling of these wind deflectors are not easily adaptable to different operating conditions. For example, the additional aerodynamic force is significantly higher in high-speed tunnels than on open track. This additional force also depends on the vehicle shape, tunnel cross-section, obstruction ratio (ratio of vehicle cross-section to tunnel cross-section), cross-sectional changes, and the pantograph's position within the train consist. Furthermore, this additional force is direction-dependent (for example, depending on whether an asymmetrical single-arm pantograph is in the upright or knee position).

[0005] In addition, there is an increasing need to increase the pantograph contact force when stationary to prevent overheating and damage to the contact strip and overhead line wire at the contact point during high current flow from lighting, air conditioning, and passenger information systems on parked vehicles. However, wind deflectors cannot provide this additional force when the vehicle is stationary.

[0006] Current technology includes single-stage and two-stage (fixed but adjustable) pressure control systems. In some cases, electro-pneumatically (ep) controlled pressure systems are already used, as described, for example, in EP 1 539 528 A1. This document demonstrates how the fallback system required by railway operators in the event of an ep controller malfunction is implemented via a changeover valve. In the event of a malfunction, the ep controller switches to a fixed, adjustable pressure reducing valve. The ep controller regulates the contact force during normal vehicle operation. A disadvantage of this system is that the contact force cannot be controlled precisely enough via the controller, resulting in high air consumption.

[0007] EP 1 862 347 A1 discloses a device for adjusting the contact pressure of a vehicle's pantograph against an overhead line. For this purpose, a pressure regulator is used, which is controlled via a separate pneumatic auxiliary control circuit. Thus, the contact pressure of the pantograph can be adapted to different driving situations.

[0008] The invention is therefore based on the objective of creating a device and a method using such a device, with which a more precise control of the required contact forces between a pantograph and an overhead line is possible, which are better suited to different operating situations.

[0009] This problem is solved according to the invention by a device for controlling or regulating a contact force between an overhead line and a current collector of a vehicle according to claim 1. Furthermore, the problem is solved by a method according to claim 13. Advantageous embodiments of the invention are contained in the dependent claims.

[0010] According to the invention, the solution to the problem consists of a device for controlling a contact force between an overhead contact line and a vehicle's pantograph, which is pneumatically or hydraulically actuated. Air or oil, for example, can be used as the pressure medium. During the raising or lowering of the pantograph, the pressure of the medium is in equilibrium with the weight of the pantograph. The required contact force is achieved by increasing the pressure of a

[0011] Working pressure is set by control, regulation, or both. In normal operating conditions—within a tolerance band of the pantograph contact force—the working pressure is controlled only by means of a base pressure. If the operating situation requires additional contact force, an additional pressure is added to the base pressure to increase the working pressure.

[0012] In a first embodiment according to the invention, the base pressure and the additional pressure are added in a working pressure control circuit to form the added pressure as the working pressure.

[0013] In a second embodiment according to the invention, an adjustment device is also provided to add the base pressure and the auxiliary pressure, to control the power pressure with the added pressure, and to establish a working pressure as the controlled power pressure. The advantage of this lies in the fact that the base pressure and the auxiliary pressure can be set with small cross-sections, i.e., small and constant volumes, while the power pressure and the working pressure are provided with large cross-sections, i.e., large and variable volumes. A pilot pressure control can typically be translated 1:1 to the high-volume working pressure. In addition, a translation ratio other than 1:1 can be implemented in one embodiment. For example, if the translation ratio 1:5 is selected, 10 bar in the pilot circuit results in an output pressure of 2 bar at the output of the relay valve.In this case, the deviation is also reduced proportionally. For example, if the deviation in the pilot circuit is ± 0.1 bar, the deviation at the output of the relay valve is only ± 0.02 bar, which corresponds to an absolute reduction of the deviation, thus enabling an increase in control accuracy and a reduction in hysteresis.

[0014] According to the invention, such a device is provided with a basic control circuit, an auxiliary control circuit, and a working pressure control circuit. The basic control circuit has a basic control circuit adjustment device (e.g., a pressure reducing valve) for setting the basic pressure. The auxiliary control circuit has a control device (e.g., a regulator) for setting the auxiliary pressure, wherein the basic pressure and the auxiliary pressure are combined at an interface to supply the working pressure to the working pressure control circuit, where further elements for influencing pressure or flow rate can be interposed. Additionally, the working pressure control circuit can be configured to limit the working pressure to a maximum value to prevent excessive pressure on the pantograph or overhead line and thus avoid damage.

[0015] In addition to the controller, the auxiliary control circuit preferably includes a pressure sensor and two control valves. The pressure sensor provides pressure signals to the auxiliary control circuit's controller. A high-resolution pressure sensor allows for a low control level (low pressures) for the auxiliary control circuit's control device and a smaller tolerance (higher control accuracy) with simultaneously reduced hysteresis. The control valves not only regulate the auxiliary pressure but are also designed to compensate for any drift of the main control circuit's adjustment device (the base pressure) in either direction (additional calibration function).

[0016] In an advantageous embodiment of the invention, a state machine is provided to monitor the base pressure, auxiliary pressure, and working pressure. If any of the pressures falls below a minimum pressure setpoint, exceeds a maximum pressure setpoint, or deviates from a range between the target and actual values, a rapid shutdown occurs. The rapid shutdown acts on the auxiliary control circuit and switches it off. The base pressure is maintained for the working pressure. Alternatively, complete venting of the working pressure can also occur via a main confirmation valve or via a piston valve or emergency brake valve located close to the current collector, with internal pressure comparison and reference pressure volume. Instead of a state machine, an electrical, electronic, or microprocessor unit (optionally with software classified according to a security level) is also possible.Comparison signals for this monitoring device can be obtained from the pressure sensor of the auxiliary control circuit and / or a pressure sensor intended for the working pressure.

[0017] A vehicle equipped with this device exhibits improved and safer driving characteristics due to a more precisely adjusted contact force between the overhead line and the pantograph.

[0018] Two embodiments of the invention are explained in more detail below with reference to the figures.

[0019] They show: Fig. 1 the required contact force depending on the vehicle speed according to the state of the art; Fig. 2 a schematic representation of a control device of a current collector according to a first embodiment of the invention; Fig. 3 a schematic representation of a control device of a current collector according to a second embodiment of the invention; Fig. 4 a detailed representation of a section of the control device according to the first embodiment of the invention;

[0020] Fig. 2 Figure 1 shows a part of a vehicle 10, a pantograph 12, an overhead line 20 and a control device 22 according to the first embodiment of the invention. The pressure medium air flows in the direction of inflow 90 from a pressure inlet 24 via an air filter 34 into the control device 22.

[0021] When the vehicle 10 is in operation or standby mode, the control device 22 is switched on via a changeover valve 28a. Changeover valve 28b and device 30 are monitoring devices.

[0022] During operation of the vehicle 10, a specific contact force is required between the pantograph 12 and the overhead line 20 to ensure a reliable transfer of energy from the overhead line 20 via the pantograph 12 to the vehicle 10. This operating pressure is achieved by a basic control circuit 56 and an auxiliary control circuit 26, forming an operating pressure control circuit 60.

[0023] A pressure is supplied to a first print media line 52, the basic control circuit 56, and the auxiliary control circuit 26. The basic control circuit 56 sets a basic pressure and the auxiliary control circuit 26 sets an auxiliary pressure, whereby the basic pressure and the auxiliary pressure are each conveyed via a second print media line 54 to the working pressure control circuit 60, in order to form the working pressure there as an addition of the basic pressure and the auxiliary pressure.

[0024] Fig. 3 Figure 1 shows a part of a vehicle 10, a pantograph 12, an overhead line 20 and a control device 22 according to the second embodiment of the invention. The pressure medium air flows in the direction of inflow 90 from a pressure inlet 24 via an air filter 34 into the control device 22.

[0025] When the vehicle 10 is in operation or standby mode, the control device 22 is switched on via a changeover valve 28a. Changeover valve 28b and device 30 are monitoring devices.

[0026] During operation of the vehicle 10, a specific contact force is required between the pantograph 12 and the overhead line 20 to ensure a reliable transfer of energy from the overhead line 20 via the pantograph 12 to the vehicle 10. This operating pressure is achieved by a pilot control circuit 32 and an adjusting device (50) to a working pressure control circuit 60.

[0027] The input control circuit 32 has a base control circuit 56 and an auxiliary control circuit 26. A print pressure is supplied to a first print media line 52, the base control circuit 56, and the auxiliary control circuit 26. The base control circuit 56 sets a base pressure, and the auxiliary control circuit 26 sets an auxiliary pressure. The base pressure and the auxiliary pressure are each conveyed via a second print media line 54 to the adjusting device 50 to control the print pressure from the first print media line 52 therein.

[0028] Fig. 4 shows a detailed representation of a section of the control device 22 in Fig. 3 The pilot control circuit 32 includes a pressure reducing valve 36, a switching valve 28c, an auxiliary control circuit 26 including a regulator 38, a pressure sensor 72a, a first control valve 76 for pressure reduction, a second control valve 78 for pressure build-up, a relay valve 40 and a pressure sensor 72b.

[0029] The pressure reducing valve 36 is designed to adjust the base pressure, and the regulator 38 is designed to adjust the auxiliary pressure, with the base pressure and the auxiliary pressure each being routed via the second pressure media line 54 to inputs 46a and 46b of the relay valve 40. The relay valve 40 is designed such that the base pressure and the auxiliary pressure are added after inputs 46a and 46b to control the power pressure from the first pressure media line 52 with the added pressure and to release the working pressure from an output 42 of the relay valve 40. The changeover valve 28c is provided to switch off the auxiliary control circuit in an emergency. The pressure sensors 72a and 72b are provided to measure the auxiliary pressure in the auxiliary control circuit 26 and the working pressure at the output 42 of the relay valve. REFERENCE MARK LIST

[0030] 10 Vehicle 12 Pantograph 20 Overhead line 22 Control device 24 Pressure inlet 26 Auxiliary control circuit 28a, 28b, 28c Diverter valve 30 Device 32 Pilot circuit 34 Air filter 36 Pressure reducing valve 38 Regulator 40 Relay valve 42 Output of a relay valve 46, 46a, 46b Input of a relay valve 50 Adjustment device 52 First pressure media line 54 Second pressure media line 56 Basic control circuit 60 Working pressure control circuit 72a, 72b Pressure sensor 76 First control valve 78 Second control valve 90 Directional arrow

Claims

1. A device (22) for controlling a pressing force from a current collector of a vehicle (10) on an overhead line (20), wherein the pressing force is actuated by means of a pneumatic or hydraulic working pressure, having: - a basic control circuit (56), - an additional control circuit (26), - a working pressure control circuit (60), wherein the basic control circuit (56) has a basic control circuit setting device which is configured to set a basic pressure from a power pressure which is made available, wherein the additional control circuit (26) has a control device which is configured to set an additional pressure from the power pressure which is made available, characterized in that the basic pressure and the additional pressure are combined at an interface, in order to increase the working pressure in the working pressure control circuit (60) by adding the additional pressure to the basic pressure.

2. The device (22) as claimed in claim 1, wherein the working pressure control circuit (60) is configured in such way that the basic pressure and the additional pressure are added together and the added pressure forms the working pressure.

3. The device (22) as claimed in claim 1, wherein a pilot control circuit (32) is provided in which the basic pressure and the additional pressure are controlled as pilot control pressures, and a setting device (50) is provided which is configured to set, in accordance with the basic pressure and the additional pressure from the pilot control circuit (32), a power pressure which is made available, and to output said power pressure as a working pressure into the working pressure control circuit (60).

4. The device (22) as claimed in claim 3, characterized in that the basic control circuit setting device of the basic control circuit (56) is formed by a pressure reducing valve (36) for setting the basic pressure.

5. The device (22) as claimed in claim 3 or 4, characterized in that the control device of the additional control circuit (26) is formed by a regulator (38) for setting the additional pressure.

6. The device (22) as claimed in one of the preceding claims 3 to 5, characterized in that a switching valve (28a) is provided as a switch-on and switch-off valve in the power pressure circuit upstream of an introduction point for the power pressure into the pilot control circuit (32) and the working pressure control circuit (60).

7. The device (22) as claimed in one of the preceding claims 3 to 6, characterized in that the setting device (50) is configured in such a way that the basic pressure and the additional pressure are added and the working pressure can be set with this combined pressure.

8. The device (22) as claimed in one of the preceding claims 3 to 7, characterized in that the additional control circuit (26) has a pressure sensor (72a) and two regulating valves (76, 78) with which the basic pressure can be calibrated in both directions.

9. The device (22) as claimed in one of the preceding claims, characterized in that an automatic state machine is provided for monitoring the basic pressure / additional pressure / working pressure, which machine is configured in such a way that it switches off the additional pressure and / or the basic pressure and / or the working pressure in situations which are to be defined.

10. The device (22) as claimed in one of the preceding claims 1 to 8, characterized in that an electric unit, electronic unit or microprocessor unit is provided for monitoring the basic pressure / additional pressure / working pressure, which unit is configured in such a way that it switches off the additional pressure and / or the basic pressure and / or the working pressure in situations which are to be defined.

11. The device (22) as claimed in one of the preceding claims, characterized in that a switching valve (28c) is provided upstream of the control device of the additional control circuit (26) in order to switch off the additional control circuit in an emergency.

12. The device (22) as claimed in one of the preceding claims, characterized in that a switching valve (28c) is provided downstream of the control device of the additional control circuit (26) in order to switch off the additional control circuit in an emergency.

13. A method for controlling a pressing force from a current collector (12) of a vehicle (10) on an overhead line (20), wherein the pressing force is actuated by means of a pneumatic or hydraulic working pressure, having the following steps: - setting a basic pressure in a basic control circuit (56), - setting an additional pressure in an additional control circuit (26), characterized by - adding the basic pressure and the additional pressure. - introducing a working pressure into a working pressure control circuit (60), wherein the added pressure forms the working pressure and the working pressure is increased by adding the additional pressure to the basic pressure.

14. The method according to claim 13, wherein the working pressure is regulated by a pressure from a pilot control circuit (32), wherein the pressure of the pilot control circuit (32) is formed by adding the basic pressure and the additional pressure.

15. A vehicle (10) having at least one device (22) as claimed in one of claims 1 to 12.