Pantograph driving system and raising or lowering method

Abstract

The invention relates to a drive system (30) and a method for raising or lowering at least one slide (31) of a pantograph of a rail vehicle, wherein the slide is arranged on a positioning device of the pantograph, the positioning device can be adjusted by the drive system, and the slide can come into contact with the overhead line by means of contact pressure, wherein the drive system comprises: a bellows drive (32), which can be actuated by compressed air and is used to actuate the positioning device; a pneumatic control unit, which comprises a control valve (46) for supplying compressed air to the bellows drive or removing compressed air from the bellows drive; and a lowering unit (34), which has a pneumatic detection line (35) and a lowering valve (36) for exhausting the bellows drive when pressure in the detection line is lost, wherein the lowering valve is a 3 / 2-way valve (37), wherein the lowering valve is arranged in a pneumatic supply line (38) between the control valve and the bellows drive.

Description

[0001] The present invention relates to a drive system and method for raising or lowering at least one slide of a current collector of a rail vehicle, wherein the slide is arranged on a positioning device of the current collector, the positioning device can be adjusted by a drive system, and the slide is configured to form contact with an overhead line by means of contact pressure, the drive system comprises a bellows drive, which is configured to be actuated by means of compressed air for actuating the positioning device, the drive system comprises a pneumatic control unit having a control valve for supplying compressed air to the bellows drive or extracting compressed air from the bellows drive, and the drive system comprises a descending unit having a pneumatic detection line and a descending valve for exhausting the bellows drive when the pressure in the detection line decreases.

[0002] Slides made of graphite are often used to transmit energy from overhead wires to vehicles, such as locomotives. For example, when the slide is severely worn or damaged, the overhead wires or overhead lines may be damaged. Therefore, locomotives are usually equipped with sensor technology, which enables the lowering of the sliding strip by means of the slide or a positioning device supporting the slide, such as a so-called pantograph, etc., when a certain expected wear limit is exceeded or the slide is damaged. The sensor technology comprises, for example, a sensor element that can be formed as a fluid-tight channel or a tubular profile or arranged in the slide. The sensor element thus forms a detection line that is affected by compressed air. When the wear limit has been reached or the slide is damaged, the detection line is damaged and compressed air escapes. A pressure drop in the detection line can be detected, which causes the positioning device to lower the slide.

[0003] In order to prevent damage, the slide must be lowered from the overhead line as quickly as possible, for which this is implemented with the aid of a lowering unit specially implemented for this purpose. Compared with the control unit by means of which the regular raising and lowering of the slide is controlled or realized, the lowering unit is intended to realize a relatively fast lowering of the slide when a pressure drop is detected. Therefore, the lowering unit usually has a lowering valve, which is connected to the detection line and is a differential pressure valve. The differential pressure valve is directly connected to the bellows drive for raising or lowering the sliding strip by means of a positioning device so that the bellows drive can be quickly exhausted. In principle, exhaust can also be achieved with the aid of a control unit, however, due to the long conduction paths and valves contained in the pneumatic circuit of the control unit, rapid exhaust is not allowed. When a pressure drop is detected by the differential pressure valve, the supply line of the bellows drive is opened by the differential pressure valve so that the compressed air contained in the bellows drive can escape from the supply line unhindered.

[0004] The differential pressure valve may be a 2 / 2-way valve which may be implemented, for example, as a diaphragm valve. After repair or replacement of the detection line or the slide, the slide may only be raised after the differential pressure valve has been reset or the damage causing the pressure drop has been repaired, since otherwise compressed air would escape from the supply line. Experience has shown that normal functions of the differential pressure valve, such as resetting the differential pressure valve at very high or very low temperatures, cannot be reliably guaranteed.

[0005] It is therefore an object of the present invention to propose a drive system and a method for raising or lowering a slide of a current collector which method allows a reliable operation of the drive system.

[0006] This object is achieved by a drive system having the features of one aspect of the invention, a current collector having the features of another aspect of the invention and a method having the features of a further aspect of the invention.

[0007] By means of a drive system for raising or lowering at least one slide of a current collector of a rail vehicle according to the present invention, the slide can be arranged on a positioning device of the current collector, the positioning device can be adjusted by the drive system, and the slide can form contact with the overhead line by means of contact pressure, the drive system includes a bellows drive, which is configured to be actuated by means of compressed air for actuating the positioning device, the drive system includes a pneumatic control unit, the pneumatic control unit has a control valve, the control valve is used to supply compressed air to the bellows drive or to extract compressed air from the bellows drive, and the drive system includes a descending unit, the descending unit has a pneumatic detection line and a descending valve for exhausting the bellows drive when the pressure in the detection line drops, the descending valve is a 3 / 2-way valve, and the descending valve is arranged in the pneumatic supply line between the control valve and the bellows drive.

[0008] Therefore, the drive system according to the present invention is implemented so that: by means of a control unit or its control valve, compressed air can be supplied to the bellows drive or compressed air can be extracted from the bellows drive for raising or lowering the slide via the positioning device. In addition, the drive system has a descending unit, which includes a detection line, and by means of the descending unit, the pressure reduction in the detection line can be detected. In this case, the descending valve is implemented as a 3 / 2-way valve and is arranged in the supply line of the bellows drive between the control valve and the bellows drive. This position of the 3 / 2-way valve allows the bellows drive to be exhausted quickly even before the control valve. In particular, by implementing the descending valve as a 3 / 2-way valve, it becomes possible to arrange the descending valve directly in the supply line of the bellows drive. The supply line from the control valve to the bellows drive can be switched to a first switching position by means of a 3 / 2-way valve so that compressed air can pass through, and in a second switching position, the supply line can be separated from the control valve so that compressed air can escape directly from the bellows drive to the environment via the 3 / 2-way valve.

[0009] In particular, it can be expected that in the reset switching position the 3 / 2-way valve generally allows compressed air to escape from the bellows drive. In addition, the 3 / 2-way valve can be actuated, for example, by means of compressed air in the test line. In this way, it is always ensured that when a loss of compressed air occurs in the test line, the 3 / 2-way valve is switched to a switching position in which compressed air escapes from the bellows drive. Since the 3 / 2-way valve is more reliable than a 2 / 2-way valve or a differential pressure valve for the application envisaged here, it is also possible to reliably achieve the raising of the slide after repairing or replacing the test line without accidentally blocking the lowering valve.

[0010] It is particularly advantageous if the descending valve is a 3 / 2-way valve with a spring return. By means of the spring return, the descending valve can be moved to a switching position in which the bellows drive is rapidly exhausted. This ensures that the slide descends in any case when the pressure in the detection line decreases. The descending valve can be configured to be pneumatically actuated via the detection line so that: when there is an operating pressure in the detection line, the descending valve opens the supply line, and when the pressure in the detection line decreases, the descending valve closes the supply line toward the control valve and exhausts the bellows drive. The pneumatic actuation of the descending valve or the 3 / 2-way valve can be achieved by the operating pressure in the detection line. If the pressure decreases relative to the operating pressure in the detection line, the descending valve can be reset to a switching position in which the bellows drive is exhausted.

[0011] The detection line can be connected to a second pneumatic supply line of the control unit for forming an operating pressure in the detection line, and the throttle valve of the descending unit is arranged in the second supply line. The detection line can be filled with compressed air via the second supply line until the operating pressure in the detection line is reached. Since the throttle valve is arranged in the second supply line, the operating pressure is compensated with a delay after the pressure in the detection line is reduced. This means that when the pressure in the detection line is reduced, the switching of the descending valve occurs because the pressure reduction in the detection line cannot be compensated quickly enough via the second supply line. In other aspects, the pressure reduction may be compensated via the second supply line, which will prevent the descending valve from operating in an unexpected manner.

[0012] The second supply line can be connected between the control valve and the compressed air source or between the control valve and the pressure regulator for forming the operating pressure. In this way, it can be ensured that the second supply line can be subjected to compressed air independently of the control valve and is not affected by the switching position of the control valve.

[0013] The lowering unit can be connected to the control unit via a pneumatic signal line, which can be connected to a pressure switch of the control unit and to a detection line. Via the signal line, the pressure drop in the detection line can be pneumatically transmitted at the pressure switch in the control unit. Via the pressure switch, the lowering of the slide can be signaled to the driver of the rail vehicle, for example in the form of an alarm or status notification. In addition, the lowering of an additional slide on an additional current collector of the rail vehicle can be actuated via the pressure switch. Thus, damage to these slides can be prevented as much as possible.

[0014] The control unit can have an additional pressure switch which is connected to the supply line between the control valve and the bellows drive. A signal can be sent to the driver of the rail vehicle via the additional pressure switch, for example, that the supply line is pressurized and therefore the slide is raised.

[0015] The control unit can be connected to a compressed air source and have a pressure regulator for forming the operating pressure. The compressed air source can be formed by the rail vehicle itself. By means of the pressure regulator, an operating pressure that is always constant can be formed. Furthermore, the control unit can also have features for purifying the compressed air and an overpressure valve for limiting the pressure.

[0016] The control valve can be a 5 / 2-way valve, which is configured to be actuated in an electromagnetic manner. By electromagnetic actuation, the driver of the rail vehicle can easily start raising or lowering, for example, by operating a switch. The 5 / 2-way valve can be configured so that: in order to raise the slide, the supply line can be directly connected to the compressed air source in the first switching position. In the second switching position, the compressed air source can be separated from the supply line or closed via the 5 / 2-way valve. In order to exhaust the bellows drive or to slowly lower the slide, the supply line can pass through the 5 / 2-way valve into the environment. In addition, the 5 / 2-way valve can be formed with a spring return member so that the supply line is exhausted in the switching position of the spring return.

[0017] The control unit may have at least one throttle check valve in the supply line, the throttle check valve being configured to be connected between the control valve and the bellows drive, by means of which the compressed air supplied to the bellows drive via the supply line can be throttled and the compressed air extracted from the bellows drive can be guided, or, by means of the throttle check valve, the compressed air supplied to the bellows drive via the supply line can be guided and the compressed air extracted from the bellows drive can be throttled. As for the speed of raising or lowering, the raising or lowering of the slide can be set as desired by the throttle check valve. The throttle check valve may be arranged in the supply line so that both the raising and lowering are decelerated. However, two throttle check valves may be arranged in a series circuit in the supply line so that the raising and lowering are each decelerated by one of the throttle check valves.

[0018] The control unit may have an additional throttle valve, by means of which the compressed air supplied to the bellows drive via the supply line or extracted from the bellows drive can be throttled. For example, if only one throttling check valve is provided in the supply line, the additional throttle valve may be provided so that, when the supply line is exhausted via the control valve, the exhaust gas is decelerated by means of the additional throttle valve, so that the slide is slowly lowered. For this purpose, the additional throttle valve may be formed with a sound absorber.

[0019] The control unit, the lowering unit and the bellows drive can be arranged spatially separated from one another. The lowering valve or the lowering unit can advantageously be arranged in the vicinity of the bellows drive, so that a quick venting of the bellows drive and a short connection to the detection line are possible. In order to protect the control unit from harmful environmental influences, the control unit can be arranged in a separate housing in or on the rail vehicle and can be connected to the bellows drive or the lowering unit via corresponding compressed air lines.

[0020] The current collector according to the invention has a positioning device and at least one slide arranged on the positioning device and a pneumatic drive system according to the invention. Further advantageous embodiments of the current collector are evident from the description of the features of the other aspects of the invention.

[0021] In the method according to the invention for raising or lowering at least one slide of a current collector of a rail vehicle by means of a drive system, the slide is arranged on a positioning device of the current collector, the positioning device being adjustable by means of the drive system and the slide being brought into contact with the overhead wire by means of a contact pressure, a bellows drive of the drive system actuates the positioning device by means of compressed air, the compressed air is supplied to the bellows drive or withdrawn from the bellows drive by means of a control valve of a pneumatic control unit of the drive system, and a pneumatic detection line and a lowering valve of a lowering unit of the drive system exhaust the bellows drive when the pressure in the detection line decreases, a 3 / 2-way valve with a spring return is used as a lowering valve, which is arranged in the pneumatic supply line between the control valve and the bellows drive. For further details of the method according to the invention, reference is made to the description of the advantages of the drive system according to the invention.

[0022] When the pressure in the detection line decreases relative to the operating pressure established by the pressure regulator of the control unit, the lowering valve can be switched in such a way that the bellows drive is exhausted directly via the lowering valve and the slide is lowered.

[0023] When the detection line is tightly sealed, the detection line can be filled with compressed air until the operating pressure formed by the pressure regulator of the control unit is reached. When the operating pressure in the detection line is reached, the lowering valve can be switched so that: the bellows drive is directly driven by compressed air via the supply line and the sliding member can be lifted.

[0024] Further advantageous embodiments of the method are apparent from the description of the features of the other aspects of the invention.

[0025] Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

[0026] FIG1 shows a circuit diagram of a drive system according to the prior art;

[0027] Figure 2 A circuit diagram of the drive system is shown.

[0028] FIG1 shows a circuit diagram according to the prior art of a drive system for raising or lowering a slide 11 of a current collector (not shown here) of a rail vehicle. The slide 11 is arranged on a positioning device of the current collector (also not shown here), which can be adjusted by the drive system. The positioning device can be, for example, a so-called pantograph or another lever arm system. In addition, the drive system 10 comprises a bellows drive 12 for actuating the positioning device. By filling the bellows drive 12 with compressed air, the slide 11 comes into contact with the overhead wire (not shown here) via the positioning device, and the slide 11 descends again when the bellows drive 12 is exhausted.

[0029] Furthermore, the drive system 10 comprises a control unit 13 and a lowering unit 14. The lowering unit 14 is formed by a pneumatic detection line 15 and a lowering valve 16, which in this case is formed by a differential pressure valve 17 or a 2 / 2-way valve. The control unit 13 is connected to a compressed air source 18 and to the bellows drive 12 via a supply line 19. The control unit 13 comprises a compressed air purifier 20, a pressure regulator 21 for forming an operating pressure, a pressure gauge 22 for displaying the operating pressure, an overpressure valve 23 for limiting the operating pressure, a throttling check valve 24, a further throttle valve 25 and a control valve 26. The control valve 26 is a 5 / 2-way valve 27 with an electromagnetic drive and a spring return member.

[0030] In the switching position of the control valve 26 illustrated in FIG1 , the bellows drive 12 is being vented. Venting occurs via the additional throttle valve 25, resulting in a slow lowering of the slide 11. When the slide 11 is raised, the control valve 26 is in its second switching position, in which the introduction of compressed air into the bellows drive 12 via the throttle nonreturn valve 24 is also slowed down.

[0031] When the bellows drive 12 is filled via the supply line 19, the test line 15 is also pressurized and the differential pressure valve 17 switches from the illustrated switching position for rapid venting to a second switching position of the differential pressure valve 17, in which the supply line 19 is tightly sealed relative to the environment. When the pressure in the test line 15 decreases, the differential pressure valve 17 enables rapid venting of the supply line or the bellows drive 12 due to the pressure difference between the supply line 19 and the test line 15.

[0032] Furthermore, the lowering unit is connected to the control unit 13 via a signal line 28 which is directly connected to the detection line 15. The signal line 28 acts on a pressure switch 29 of the control unit 13, by means of which a parallel lowering of other current collectors arranged on the rail vehicle can be initiated.

[0033] Figure 2A drive system 30 is shown for raising or lowering a slide 31 of a current collector (not shown here) of a rail vehicle via a positioning device (also not shown here). The drive system 30 comprises a bellows drive 32 for actuating the positioning device and a control unit 33 as well as a lowering unit 34 for exhausting the bellows drive 32 and for rapidly lowering the slide 31. The lowering unit 34 comprises a detection line 35 and a lowering valve 36 for exhausting the bellows drive 32, which is a 3 / 2-way valve 37 and, in this case, is arranged in a supply line 38 of the bellows drive 32.

[0034] The control unit 33 is connected to a compressed air source 39 and has a supply line 38. The control unit 33 also includes a compressed air purifier 40, a pressure regulator 41, a pressure gauge 42, an overpressure valve 43, a throttling check valve 44 and a further throttle valve 45. In addition, the control unit 33 includes a control valve 46, which in this case is a 5 / 2-way valve that can be actuated electromagnetically and has a spring return. The function of the control unit 33 corresponds to the function of the control unit described in FIG. 1 to a large extent. Here, by contrast, the detection line 35 is connected to a second supply line 48 of the control unit 33, via which an operating pressure is formed in the detection line 35. Therefore, the second supply line 48 is connected to the supply line 38 downstream of the pressure regulator 41 and upstream of the control valve 46. In addition, a signal line 49 with a pressure switch 50 of the control unit 33 is connected to the detection line 35.

[0035] In addition to the lowering valve 36, the lowering unit 34 has a throttle valve 51 in the second supply line 48. Filling or increasing the pressure in the signal line 49 and the detection line 35 is achieved in a decelerated manner via the second supply line 48 and the throttle valve 51. In this case, the throttle valve 51 can alternatively be a gate or a bottleneck in the second supply line 48. When the pressure in the detection line 35 decreases, this pressure decrease cannot be immediately compensated via the second supply line 48. The detection line 35 is connected to the 3 / 2-way valve 37 and allows actuation of the 3 / 2-way valve 37.

[0036] In the illustrated switching position, the bellows drive 32 is exhausted via the 3 / 2-way valve 37. This switching position is reached by the spring return element of the 3 / 2-way valve 37 when the pressure in the test line 35 decreases. When the operating pressure in the test line 35 is reached, the 3 / 2-way valve 37 is switched to the second switching position, in which the supply lines 38 are switched to be connected to each other or uninterrupted. The slide 31 can then be raised or lowered unhindered by means of the bellows drive 32.

Claims

1. A drive system (30) for raising or lowering at least one slide (31) of a current collector of a rail vehicle, the slide being arranged on a positioning device of the current collector, the positioning device being adjustable by the drive system, and the slide being configured to come into contact with an overhead line by means of contact pressure, the drive system comprising a bellows drive (32) configured to be actuated by means of compressed air for actuating the positioning device, the drive system comprising a pneumatic control unit having a control valve (46) for supplying compressed air to the bellows drive or extracting compressed air from the bellows drive, and the drive system comprising a lowering unit (34) having a pneumatic detection line (35) and a lowering valve (36) for exhausting the bellows drive when the pressure in the detection line decreases, It is characterized in that The lowering valve is a 3 / 2-way valve (37) which is arranged in a pneumatic supply line (38) between the control valve and the bellows drive. The detection line (35) is connected to a pneumatic second supply line (48) of the control unit (33) for forming an operating pressure in the detection line, and a throttle valve (51) of the descending unit (34) is arranged in the second supply line, wherein the second supply line (48) is connected between the control valve (46) and a compressed air source (39) or between the control valve and a pressure regulator (41) for forming an operating pressure.

2. The drive system according to claim 1, It is characterized in that The lowering valve is a 3 / 2-way valve with a spring return element.

3. The drive system according to claim 1 or 2, It is characterized in that The descending valve (36) is configured to be pneumatically actuated via the detection line (35) so that: when an operating pressure is present in the detection line, the descending valve opens the supply line (38), and when the pressure in the detection line decreases, the descending valve closes the supply line toward the control valve and exhausts the bellows driver (32).

4. The drive system according to claim 1 or 2, It is characterized in that The lowering unit (34) is connected to the control unit (33) via a pneumatic signal line (49), which is connected to a pressure switch (50) of the control unit and to the detection line (35).

5. The drive system according to claim 1 or 2, It is characterized in that The control unit (33) has an additional pressure switch which is connected to the supply line (38) between the control valve (46) and the bellows drive (32).

6. The drive system according to claim 1 or 2, It is characterized in that The control unit (33) is connectable to the compressed air source (39) and has the pressure regulator (41) for establishing the operating pressure.

7. The drive system according to claim 1 or 2, It is characterized in that The control valve (46) is a 5 / 2-way valve (47) which is configured to be actuated electromagnetically.

8. The drive system according to claim 1 or 2, It is characterized in that The control unit (33) has at least one throttle check valve (44) in the supply line (38), which is connected between the control valve (46) and the bellows drive (32), by means of which the compressed air supplied to the bellows drive via the supply line can be throttled and the compressed air extracted from the bellows drive can be guided, or, by means of the throttle check valve, the compressed air supplied to the bellows drive via the supply line can be guided and the compressed air extracted from the bellows drive can be throttled.

9. The drive system according to claim 8, It is characterized in that The control unit (33) has an additional throttle valve (45), by means of which the compressed air supplied to the bellows drive (32) via the supply line (38) or the compressed air extracted from the bellows drive can be throttled.

10. The drive system according to claim 1 or 2, It is characterized in that The control unit (33), the lowering unit (34) and the bellows driver (32) are arranged to be spatially separated from each other.

11. Current collector having a positioning device, at least one slide (31) arranged on the positioning device and a drive system (30) according to any of the preceding claims.

12. A method for raising or lowering at least one slide (31) of a current collector of a rail vehicle by means of a drive system (30), the slide being arranged on a positioning device of the current collector, the positioning device being adjustable by means of the drive system and the slide coming into contact with an overhead line by means of contact pressure, the bellows drive (32) of the drive system actuating the positioning device by means of compressed air, the compressed air being supplied to or extracted from the bellows drive by means of a control valve (46) of a pneumatic control unit (33) of the drive system, and the pneumatic detection line (35) and the lowering valve (36) of the lowering unit (34) of the drive system exhausting the bellows drive when the pressure in the detection line decreases, It is characterized in that A 3 / 2-way valve (37) with a spring return element is used as a lowering valve, which is arranged in a pneumatic supply line (38) between the control valve and the bellows drive. The detection line (35) is connected to a pneumatic second supply line (48) of the control unit (33) for forming an operating pressure in the detection line, and a throttle valve (51) of the descending unit (34) is arranged in the second supply line, wherein the second supply line (48) is connected between the control valve (46) and a compressed air source (39) or between the control valve and a pressure regulator (41) for forming an operating pressure.

13. The method according to claim 12, It is characterized in that When the pressure in the detection line (35) decreases relative to the operating pressure formed by the pressure regulator (41) of the control unit (33), the descending valve (36) is switched so that: the bellows drive (32) is exhausted directly via the descending valve, and the sliding member (31) descends.

14. The method according to claim 12 or 13, It is characterized in that When the detection line (35) is tightly sealed, the detection line (35) is filled with compressed air until the operating pressure formed by the pressure regulator (41) of the control unit (33) is reached. When the operating pressure in the detection line is reached, the lowering valve (36) is switched so that: the bellows drive (32) is directly driven by compressed air via the supply line (38), and the sliding member (31) rises.

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