Lifting unit for a tamping machine

Abstract

Lifting unit (10) for a track construction machine (1) for lifting a track (2) to be tamped, comprising roller lifting clamps (15) with clamp levers (16) which are adjustably mounted in a unit frame (14) by means of swivel drives (20), wherein a roller lifting plate (18) rotatable about a pivot axis (17) is arranged on each clamp lever (16). The respective roller lifting plate (18) is rotatably mounted in a sleeve (26), the sleeve (26) being adjustably guided in the direction of the pivot axis (17) in a holder (29) of the associated clamp lever (16) by means of a drive (27, 28). By actuating the drive (27, 28), the associated roller lifting plate (18) together with the associated sleeve (26) can be adjusted to the height of a rail head without the need for manual adjustment by an operator.

Description

Technical area

[0001] The invention relates to a lifting unit for a track construction machine for lifting a track to be tamped, comprising roller lifting tongs with tong levers which are mounted in an unit frame so as to be adjustable about pivot axes by means of pivot drives, wherein a roller lifting plate which is rotatable about a rotation axis is arranged on each tong lever and which is guided in a holder so as to be adjustable in the direction of the rotation axis by means of a drive. State of the art

[0002] Such a lifting unit is known, for example, from AT 388949 B. The lifting unit is designed as a lifting and straightening unit and comprises six roller lifting plates. Four of these roller lifting plates are arranged in pairs in a respective roller lifting clamp. To lift a track, the respective roller lifting clamp grips a rail with an outer and an inner roller lifting plate below the rail head. Each roller lifting plate is attached to a clamp lever. The two clamp levers of the respective roller lifting clamp are mounted around a common axis of rotation. Each clamp lever can be pivoted around the common axis of rotation by a separate hydraulic pivot drive. Description of the invention

[0003] The invention is based on the object of improving a lifting unit of the type mentioned above so that it can be easily used on different tracks. Furthermore, the aim is to avoid hazards when adapting the lifting unit and increase the operator's work safety.

[0004] According to the invention, these objects are achieved by the features of independent claim 1. Dependent claims specify advantageous embodiments of the invention.

[0005] Each roller lifting plate is rotatably mounted in a sleeve, with the sleeve being guided in a holder of the associated clamp lever by means of a drive in the direction of the associated rotation axis. By operating the drive, the associated roller lifting plate and its associated sleeve can be adjusted to the height of a rail head without an operator having to make any manual adjustments in a hazardous area. On the one hand, this allows for remote-controlled adjustment to different rail types. On the other hand, the drive-based adjustment of the roller lifting plates compensates for wear on the rails caused by rail vehicles in regular operation or by rail grinding during maintenance.

[0006] Advantageously, the adjustment range of the sleeve relative to the associated bracket is at least 32 millimeters, in particular at least 40 millimeters. With the 32-millimeter adjustment range, rail head differences between common rail types can be compensated, for example, between a UIC60 rail and a UIC54 rail. In addition, wear up to the permissible wear limit of 14 millimeters on main tracks can be compensated. With an extended adjustment range of at least 40 millimeters, wear up to the permissible wear limit of 22 millimeters on sidings can also be accommodated.

[0007] In a preferred variant, a hydraulic cylinder for adjusting the sleeve is arranged in the holder. Such a hydraulic cylinder requires little space and is protected from external influences within the holder. Furthermore, high lifting forces can be transmitted. The hydraulic cylinder is preferably hydraulically locked after adjustment of the associated roller lifting plate.

[0008] In a further development of this variant, the sleeve incorporates a piston from the hydraulic cylinder. This enables a particularly compact design and efficient power transmission.

[0009] Another advantageous variant includes an actuator that is attached to the respective tong lever and coupled to the associated sleeve. This allows for easy adaptation to an existing lifting unit with manual roller lifting plate adjustment. All that is required is to provide a mounting option on each existing tong lever, and each existing sleeve is replaced with a connectable sleeve.

[0010] In a preferred embodiment of this variant, the sleeve is guided in the associated holder by means of a spindle thread, with the actuator being designed as a rotary drive. This allows for finely adjustable adjustment of the respective roller lifting plate. A self-locking feature of the spindle thread ensures reliable transmission of the lifting force to the associated rail.

[0011] Advantageously, the rotary drive is a hydraulic motor connected to lockable hydraulic valves. Such a hydraulic motor is compact, so the pivoting movement of the associated tong lever is not obstructed. Furthermore, when the hydraulic valves are locked, the hydraulic motor blocks any unintentional adjustment of the associated roller lifting plate.

[0012] In a preferred design, the respective sleeve has external teeth, and the associated actuator is connected to a gear that meshes with the external teeth. This arrangement is robust and enables reliable transmission of rotary motion from the rotary drive to the associated sleeve.

[0013] It makes sense to have the outer toothing longer than the thickness of the gear. This allows for a large adjustment range, while the gear always remains in engagement with the outer toothing despite its small thickness. The small thickness of the gear is useful for a space-saving arrangement of the drive unit consisting of the rotary drive and the gear.

[0014] In a further development, the respective actuator is attached to the associated clamp lever with a bracket that can be adjusted in the direction of the rotation axis. This allows for a further extension of the adjustment range, whereby the respective sleeve can be rotated further out of the associated holder while the gear remains engaged with the external toothing. Short description of the drawings

[0015] The invention is explained below by way of example with reference to the accompanying figures. They show schematically: Fig. 1Track construction machine with lifting unit Fig. 2Track cross-section with lifting unit Fig. 3Lifting unit half on a track in an oblique view Fig. 4Roller lifting tongs with rotation drives and downward-facing swivel cylinders in an oblique view Fig. 5Roller lifting tongs according to Fig. 4 in a front view Fig. 6Roller lifting tongs with rotary drives and interlocked swivel cylinders in an oblique view Fig. 7Roller lifting tongs according to Fig. 6 in closed position Fig. 8Rolling lifting tongs according to Fig. 6 in open position Fig. 9Roller lifting tongs with hydraulic cylinder for adjusting the respective roller lifting plate Fig. 10Sectional view of a tong lever of the roller lifting tongs according to Fig. 9 Description of the embodiments

[0016] One in Fig. 1The track construction machine 1 shown is a tamping machine for tamping a track 2 and switches. For continuous operation, a satellite 4 is arranged which can be moved longitudinally relative to a main machine 3. During operation, the main machine 3 moves continuously with rail carriages 5 on rails 6 of track 2. The satellite 4 is supported on another rail carriage 5 and on the main machine 3 and moves cyclically in a working direction 7 from sleeper 8 to sleeper 8. In a cyclically operating tamping machine, the entire machine moves from sleeper 8 to sleeper 8. A tamping unit 9 and a lifting unit 10 are arranged on a machine frame 11.

[0017] During operation, each sleeper 8 is tamped using the tamping unit 9, while the track grid formed by rails 6 and sleepers 8 is lifted to a desired position using the lifting unit 10. A measuring system 12 is mounted on the machine 1 to measure the current track position. Measurement results from the measuring system 12 are compared with desired values, resulting in control values ​​for controlling the lifting unit 10 using a control device 13.

[0018] The lifting unit 10 comprises at least one roller lifting tong 15 for each rail 6 of the track 2, arranged on a unit frame 14. Each roller lifting tong 15 has two tong levers 16 that can be pivoted relative to one another, each with a roller lifting plate 18 that can be rotated about a rotation axis 17. Preferably, both tong levers 16 of the respective roller lifting tong 15 are pivotally mounted on the unit frame 14 about a common pivot axis 19. Each tong lever 16 is coupled to its own pivot drive 20. By closing the respective roller lifting tong 15 by means of the pivot drives 20, the associated rail 6 can be gripped with an inner roller lifting plate 18 and an outer roller lifting plate 18.

[0019] The unit frame 14 is connected to the machine frame 11 by means of a lifting cylinder 21. In the exemplary lifting unit 10 in Fig. 1Two front roller lifting tongs 15 and two rear roller lifting tongs 15 are arranged in the working direction 7. At the front, the lifting unit 10 is guided on the machine frame 11 so that it can be adjusted in the longitudinal direction of the track. For precise lifting of the track grid in the area of ​​the tamping unit 9, the lifting cylinders 21 are conveniently positioned above the rear roller lifting tongs 15.

[0020] In a tamping machine, the lifting unit 10 is usually designed as a lifting and straightening unit. Therefore, two straightening rollers 22 are assigned to each rail 6 between the front and rear roller lifting tongs 15. These straightening rollers 22 transmit a lateral movement of the lifting unit 10, caused by straightening cylinders 23, to the rail grid. For use in switches, a height-adjustable lifting hook 24 is also arranged on the unit frame 14 for each rail 6.

[0021] The height of the lifting unit 10 relative to the rails 6 is determined by the straightening rollers 22 mounted in the unit frame 14. This determines the position of the respective roller lifting tongs 15 relative to the assigned rail 6. Specifically, the position of the pivot axis 19 of the respective roller lifting tongs 15 is fixed. The same applies to a design of the respective roller lifting tongs 15 with separate pivot axes 19 for each tong lever 16. In any case, the positions of the roller lifting plates 18 arranged on the tong levers 16 must be adjusted to a rail head height 25 of the rails 6 to be gripped.

[0022] According to the invention, the respective roller lifting plate 18 is rotatably mounted in a sleeve 26, wherein the sleeve 26 is guided in a holder 29 of the associated clamp lever 16 by means of a drive 27, 28 in the direction of the rotation axis 17. Such a drive is, for example, an actuator 27 arranged externally on the clamp lever 16 and coupled to the sleeve 26. Figures 2-8 A rotary drive is shown as the actuator 27, but the invention also includes an actuator 27 designed as a linear drive. Another alternative is a hydraulic cylinder 28 integrated in the holder, which is connected to a hydraulic system ( Figs. 9 and 10 ).

[0023] Viewed in working direction 7, the lifting unit 10 is in Fig. 2, whereby the rear roller lifting tongs 15 are particularly visible. The left roller lifting tong 15 is shown in the open position and the right roller lifting tong 15 grips the associated rail 6 in the closed position. The latter is also shown in Fig. 3 shown in an oblique view. The Figures 4 and 5 show the released roller lifting tongs 15 together with the swivel drives 20 in a central position.

[0024] In this embodiment, the respective sleeve 26 has an external toothing 30. The respective external toothing 30 engages with a gear 31, which is connected to a drive shaft of the associated actuator 27. The respective gear 31 is preferably designed as a spur gear in module 2. A hydraulic motor, for example, is used as the actuator 27.

[0025] The associated sleeve 26 is guided in the respective holder 29 by a spindle thread 32. For this purpose, the respective sleeve 26 has an external thread that is screwed into a corresponding internal thread of the associated holder 29. This spindle thread 32 is preferably designed with a pitch of 2 millimeters per revolution. The length of the internal thread and the length of the external thread are coordinated to ensure a sufficient adjustment range.

[0026] With this arrangement, actuation of the respective actuator 27 causes the associated roller lifting plate 18 to be adjusted in the direction of the rotation axis 17. The height of the respective external toothing 30 depends on the desired adjustment range and is, for example, 40 millimeters. The thickness of the associated gear 31 is, for example, 20 millimeters, so that with an adjustment range of 40 millimeters, an engagement height of 10 millimeters remains in each end position. This allows the lifting unit 10 to be adapted to different rail types at any time. In particular, adaptation to different wear states of a rail line during operation is possible without an operator having to enter a danger zone.

[0027] For an additional adjustment range, the respective actuator 27 is attached to the associated clamp lever 16 with a bracket 33 that is adjustable in the direction of the rotation axis 17. This allows, for example, the respective sleeve 26 to be rotated further out of the associated holder 29. To do this, the associated actuator 27 is displaced downwards using the bracket 33 so that a minimum engagement height with the gear 31 is maintained. For example, the bracket 33 is screwed firmly to the clamp lever 16, with elongated holes in the bracket 33 determining the additional adjustment range. For example, this additional adjustment range is 5 millimeters to 20 millimeters, in particular 10 millimeters. The adjustment of the respective actuator 27 is particularly suitable for adapting the lifting unit 10 to different locations with different rail types.

[0028] In a preferred variant, the respective actuator 27 is designed as a hydraulic motor. The respective hydraulic motor is controlled via hydraulic valves, which, in a locked position, prevent undesired adjustment of the respective sleeve 26. Such hydraulic motors enable the retrofitting of an existing lifting unit 10, which already has sleeves 26 adjustable in the brackets 29. Due to the small space requirement of the hydraulic motors, the pivotability of the tong levers 16 within the unit frame 14 is not hindered. Only subsequent mounting options for the actuators 27 must be created and existing sleeves replaced with sleeves 26 with external gearing 30.

[0029] The rear roller lifting tongs 15 ( Fig. 2-5) are designed for the transmission of high lifting forces. The roller lifting plates 18 are designed with a sufficiently large diameter to prevent high compressive stresses during use due to the correspondingly large contact surfaces with the rail heads. To ensure effective transmission of vertical lifting forces, the gripper levers 16 and the associated swivel drives 20 are oriented diagonally downward in the closed position.

[0030] Compared to the roller lifting plates 18 of the rear roller lifting tongs 15, the roller lifting plates 18 of the front roller lifting tongs 15 ( Fig. 6-8 ) has a smaller diameter and a higher cylindrical section above a roller ring. This also guides the respective rail 6 laterally, whereby a lateral movement caused by the straightening cylinders 23 is better transmitted to the rail grid. To better absorb horizontal forces, the associated swivel drives 20 are arranged offset.

[0031] The Figures 9 and 10 The variant shown with hydraulic cylinders 28 in the holders 29 does not require any additional space compared to a conventional roller lifting tong 15. Fig. 9 shows the left pliers lever 16 with retracted sleeve 26. On the right pliers lever 16, the sleeve 26 together with the roller lifting plate 18 is extended in the direction of the corresponding rotation axis 17.

[0032] A piston 34 is formed in the upper region of each sleeve 26, sealing a pressure chamber 35 located below it against a cylinder wall of the associated holder 29. The cylinder arranged in the holder 29 is closed at its bottom by a cover 36. A piston rod portion 37 of the sleeve 26 is guided through this cover 36 with a seal. At the top, the sleeve 26 is supported against an upper side of the holder 29 by a return spring 38.

[0033] The pressure chamber 35 of the respective holder 29 is connected to a hydraulic system via a lateral bore 39. When the pressure chamber 35 is subjected to system pressure, the sleeve 26, together with the roller lifting plate 18 mounted therein, is pushed upward. After an adjustment, the pressure chamber 35 is hydraulically locked, so that the sleeve 26 is blocked within the holder 29. To adjust the respective roller lifting plate 18 downward, the pressure in the associated pressure chamber 35 is reduced. As a result, the return spring 38 presses the corresponding sleeve 26 downward, whereby the adjustment range is limited by stop elements 40 arranged in the pressure chamber 35.

[0034] To prevent rotation of the respective sleeve 26 in the associated holder 29, an anti-rotation device 41 is provided. This is, for example, an angle element with two legs, one leg being screwed to the outside of the holder 29 and the other leg being guided in a longitudinal groove of the sleeve 26.

Claims

1. A lifting unit (10) for a track maintenance machine (1) for lifting a track (2) to be tamped, comprising roller lifting clamps (15) with clamp levers (16) which are mounted in a unit frame (14) so as to be adjustable about pivot axes (19) by means of pivot drives (20), with a roller lifting disc (18) that can rotate about an axis of rotation (17) being arranged on each clamp lever (16) and being adjustably guided in a holder (29) in the direction of the axis of rotation (17) by means of a drive (27, 28), characterized in that the respective roller lifting disc (18) is mounted to rotate in a sleeve (26) and in that the sleeve (26) is adjustably guided in the holder (29) of the assigned clamp lever (16) in the direction of the axis of rotation (17) by means of the drive (27, 28).

2. A lifting unit (10) according to claim 1, characterized in that an adjustment range of the sleeve (26) relative to the associated holder (29) is at least 32 millimetres, in particular at least 40 millimetres.

3. A lifting unit (10) according to claim 1 or 2, characterized in that a hydraulic cylinder (28) is arranged in the holder (29) for adjusting the sleeve (26).

4. A lifting unit (10) according to claim 3, characterized in that the sleeve (26) has a piston (34) of the hydraulic cylinder (28).

5. A lifting unit (10) according to claim 1 or 2, characterized in that an actuating drive (27) is fastened to the respective clamp lever (16) and coupled to the assigned sleeve (26).

6. A lifting unit (10) according to claim 5, characterized in that the sleeve (26) is guided in the assigned holder (29) by means of a spindle thread (32) and in that the actuating drive (27) is designed as a rotation drive.

7. A lifting unit (10) according to claim 6, characterized in that the rotation drive is a hydraulic motor and in that the hydraulic motor is connected to lockable hydraulic valves.

8. A lifting unit (10) according to one of the claims 5 to 7, characterized in that the respective sleeve (26) has external teeth (30) and in that the associated actuating drive (27) is connected to a gearwheel (31) meshing with the external teeth (30).

9. A lifting unit (10) according to claim 8, characterized in that a length of the external teeth (30) is larger than a thickness of the gearwheel (31).

10. A lifting unit (10) according to one of the claims 5 to 9, characterized in that the respective actuating mechanism (27) is fastened to the assigned clamp lever (16) with a bracket (33) that can be adjusted in the direction of the axis of rotation (17).

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