Stuffing device and method for tamping sleepers of a track

Description

Technical field

[0001] The invention relates to a tamping unit for tamping under the sleepers of a track, comprising tamping tools mounted on a height-adjustable tool carrier opposite each other with respect to a vertical center plane, each of which is connected to an auxiliary drive for generating an auxiliary movement. The invention further relates to a tamping assembly comprising the corresponding tamping unit and a method for operating the tamping unit. State of the art

[0002] A generic tamping unit and a tamping assembly with several corresponding tamping units are known from AT 522456 A4. To achieve a narrow design, two hydraulic cylinders are arranged one above the other as auxiliary drives. Each hydraulic cylinder is oriented approximately horizontally and, during an auxiliary operation, pushes an upper lever arm of the associated tamping tool outwards. This brings the lower lever arms of the tamping tools, with their attached tamping picks, into alignment with each other. A vibration movement is superimposed on the auxiliary movement by means of a suitably configured hydraulic control system. A chamber of the hydraulic cylinder is subjected to pulsating pressure. Alternatively, the auxiliary drives can be connected to an eccentric drive for vibration impingement.

[0003] A tamping unit with tamping units for tamping multiple sleepers is also disclosed in AT 520267 A1, in which staggered auxiliary cylinders are connected to a vibratory drive via console-like transmission elements. The resulting narrow design (e.g., a maximum dimension of 550 mm in the longitudinal direction of the track) allows several tamping units to be arranged in a row to form a series tamping unit, with which several adjacent sleepers can be tamped simultaneously. Compared to conventional tamping units, the staggered arrangement of the auxiliary cylinders requires further design modifications to avoid unfavorable load conditions.

[0004] Another stuffing unit is known from the CH650819A5. Description of the invention

[0005] The invention is based on the objective of improving a stuffing unit of the type mentioned above in such a way that a narrow design is enabled and unfavorable load conditions are avoided. Furthermore, it is an objective of the invention to provide a method for operating the corresponding stuffing unit.

[0006] According to the invention, these problems are solved by the features of independent claims 1 and 14. Dependent claims specify advantageous embodiments of the invention.

[0007] Each tamping tool is equipped with a lever arm and a connecting part projecting beyond the central plane. The connecting part of each lever arm is linked to its associated auxiliary drive. The central plane divides the tamping unit into two halves, with each half containing the respective tamping tool and the auxiliary drive of the opposing tamping tool. This arrangement results in an almost symmetrical design of all drive and transmission elements, with optimized load distribution during operation. Even the offset arrangement of the lever arms is possible without disruptive torsional loads, provided the connecting parts are appropriately designed. Advantageously, each auxiliary drive is positioned above the tamping tool coupled to the other auxiliary drive.In addition to its narrow design, the arrangement according to the invention also offers optimal power transmission from the respective auxiliary drive to the associated tamping tool.

[0008] In a preferred embodiment, one lever arm protrudes through a fork-shaped opening in the other lever arm. With this forked lever arm, both fork ends form the connecting part for linking to the associated auxiliary drive. This avoids torsional moments and asymmetrical loads.

[0009] In a further improvement, the effective axis of the respective ordering drive forms an acute angle with the center plane, in particular an angle of up to 30°. This effective axis determines the direction of the force exerted by the auxiliary drive on the associated tamping tool. An almost vertical effective axis facilitates a narrow design of the tamping unit and optimal power transmission. The connecting parts and the bearing points where the tamping tools are mounted on the tool carrier are located at approximately the same height to achieve the best leverage.

[0010] In a preferred configuration, each auxiliary drive is connected to an eccentric shaft of a vibratory drive. This results in high process reliability because a vibration amplitude determined by the eccentricity of the eccentric shaft is maintained even under high counterforces from a contaminated ballast bed. The auxiliary drives transmit the vibration to the associated tamping tools, thus optimizing penetration into the ballast bed and ballast compaction beneath the sleepers.

[0011] Advantageously, balancing masses are arranged on the eccentric shaft. These compensate, if necessary, for vertical vibrations that might arise from the oscillating masses of the auxiliary drives. However, vertical vibrations can also be used intentionally to improve the penetration process into the ballast bed.

[0012] In an alternative version, each auxiliary drive is configured as a hydraulic cylinder to generate a vibration superimposed on the ordering movement. The respective hydraulic cylinder is mounted directly on the tool carrier and is controlled via a servo or proportional valve.

[0013] Advantageously, each auxiliary drive is coupled with a displacement sensor to detect its travel. This allows the auxiliary drives to be controlled based on their position. This enables easy adaptation to different sleeper spacings or double sleepers by adjusting the opening width of the tamping tools before they penetrate the ballast bed. The displacement sensor is also used to generate hydraulic vibrations.

[0014] In a further improvement, each auxiliary drive is coupled to an adjustable stop device in such a way that, when the respective tamping tool is reset, a stop element can be moved against a stop. In this way, the retraction of the tamping tools is stopped by the stop device.

[0015] In an advantageous further development, the respective stop device comprises a spindle and a stop element rotatably mounted on it. This allows the opening width of the tamping tools to be precisely adjusted in the reset position.

[0016] In a further improvement, the respective stop device includes an adjustable spacer element, which can be moved from a pivoted position to a position between the stop and the stop element by means of an actuator. Depending on the position of the spacer element, different opening widths can be set to accommodate double sleepers or changed sleeper spacing.

[0017] In its simplest form, each tamping tool comprises a tamping pick holder with two tamping picks attached to it. This allows track sections without points or crossings to be tamped efficiently and to a high standard.

[0018] In another advantageous embodiment, at least one tamping pick of the respective tamping tool is arranged in an upwardly pivoting tamping pick holder. In turnouts and crossings, as well as in the presence of obstacles on the track, the corresponding tamping picks can be pivoted upwards to avoid collisions with rails, sleepers, or track obstructions. The other tamping picks of the respective tamping unit can still be inserted into and positioned within free spaces of a turnout or crossing.

[0019] For a tamping unit to achieve higher performance, it is advantageous to arrange several of the described tamping units in series for the simultaneous tamping of adjacent track sleepers, with each tamping unit being individually height-adjustable by means of an associated height-adjusting drive. The series arrangement of the narrow tamping units also enables the tamping of adjacent sleepers with small sleeper spacings.

[0020] In the inventive method for operating the described tamping unit, during an adjustment process, the tamping tools immersed in a gravel bed are adjusted by pulling the connecting part of the respective lever arm upwards by means of the associated adjustment drive. This adjustment movement is carried out with optimal force application of the respective adjustment drive to the associated tamping tool. Furthermore, if an eccentric drive is present, a reliable transmission of vibration to the tamping tools is ensured.

[0021] In the method for operating a tamping unit with several tamping units arranged in series, to adapt to a changed sleeper spacing, at least some of the auxiliary drives adjust their respective stop devices by means of an actuator moving a spacer element between a stop and a stop element. This allows, for example, a quick change in the starting positions of the tamping picks when transitioning between concrete and wooden sleepers. Brief description of the drawings

[0022] The invention is explained below by way of example with reference to the accompanying figures. These show, in schematic representation: Fig. 1 Stuffing unit with eccentric shaft in a side view. Fig. 2 Stuffing unit according to... Fig. 1 In a front view Fig. 3, auxiliary cylinder; in a front view Fig. 4, auxiliary cylinder according to Fig. 3In a side view, Fig. 5: Tamping unit without eccentric shaft; Fig. 6: Tamping unit with pivoting picks; Fig. 7: Row tamping unit; Fig. 8: Row tamping unit when tamping concrete sleepers; Fig. 9: Row tamping unit when tamping wooden sleepers Description of the embodiments

[0023] The Figures 1 and 2Figure 1 shows a tamping unit 1 with a tool carrier 2, which is arranged in an aggregate frame 4 so as to be height-adjustable by means of a height adjustment drive 3. The aggregate frame 4 is preferably slidably and rotatably arranged on a machine frame of a tamping machine. Tamping tools 7 are mounted opposite each other at two bearing points 5 of the tool carrier 2 with respect to a vertical center plane 6. Each tamping tool 7 comprises a tamping pick holder 8 in which two tamping picks 9 are attached side by side. According to the invention, a lever arm 10 of each tamping tool 7 with a connecting part 11 projects beyond the center plane 6. An associated auxiliary drive 12 is connected to this connecting part 11. The connecting part 11 is, for example, designed as a hinge eye and forms a pivot joint with a clevis head of the auxiliary drive 12.

[0024] According to the invention, the connecting parts 11 and the bearing points 5 are located at approximately the same height, resulting in optimal leverage. The auxiliary drives 12 are designed as hydraulic cylinders (e.g., 80 mm piston diameter and 60 mm rod diameter) and are oriented approximately vertically upwards. Electric linear actuators can also be used as auxiliary drives 12. Preferably, an effective axis 13 of the auxiliary drive 12 forms an acute angle α with the central plane 6, particularly in a range of 0° to 30°, more specifically from 1° to 20°, and more specifically from 5° to 15°. This results in improved force transmission from the auxiliary drives 12 to the lever arms 10 as the specified ranges become increasingly narrower.

[0025] The invention also includes other embodiments. For example, the bearing points 5 and the lever arms 10 are arranged in an upper region of the tool carrier 2, and the auxiliary drives 12 are oriented downwards. In another embodiment, the bearing points 5 are arranged in the lower region of the tool carrier 2, and the lever arms 10 are extended upwards to such an extent that the auxiliary drives 12 can be oriented downwards.

[0026] Advantageously, the auxiliary drives 12 are mounted on a common eccentric shaft 14. Between two bearing points of the eccentric shaft 14, a central shaft section with a first eccentricity and, on either side of this, two shaft sections with a second eccentricity are formed. One of the two auxiliary drives 12 comprises a rod end 16, laterally offset with respect to an axis of symmetry 15, which is mounted on the central shaft section of the eccentric shaft 14. The other auxiliary drive 12 has a fork-shaped rod end 17. This rod end 17 is mounted on the shaft sections with the second eccentricity. The effective axis 13 forms an angle α of, for example, 10° with the central plane 6, so that, with sufficient freedom of movement of the auxiliary drives 12, optimal force transmission to the lever arms 10 takes place.

[0027] An electric or hydraulic rotary drive 18 is connected to the eccentric shaft 14. When the eccentric shaft 14 rotates, the eccentricities cause a vibration that is transmitted to the tamping tools 7 via the auxiliary drives 12. For example, a rotational speed of 35 revolutions per second results in a vibration frequency of 35 Hz. The vibration frequency can be adjusted by changing the rotational speed. For example, the vibration frequency is increased during the penetration process of the tamping picks 9 (e.g., to 45 Hz). To reduce noise emissions and vibration, the rotational speed of the rotary drive 18 is reduced when the tamping picks 9 are not in the ballast bed. An electric rotary drive 18 is particularly suitable for quickly adjusting the vibration frequency.

[0028] The angular positions of the two eccentricities are coordinated such that the tamping tools 7 can be set into vibration in opposite directions. To prevent vertical vibrations, the oscillating masses of the auxiliary drives 12 and the lever arms 10 are balanced by counterweights 19 on the eccentric shaft 14. Both eccentricities are, for example, 2 mm, which, via a lever ratio (e.g., 1:2.3) of the respective tamping tool 7, results in a vibration amplitude at the end of the associated tamping pick 9 (e.g., 4.6 mm).

[0029] In the illustrated variant, each auxiliary drive 12, designed as a hydraulic cylinder, includes an adjustable stop device 20 that limits the stroke of the hydraulic cylinder. This allows the opening width 21, with which the tamping picks 9 penetrate a ballast bed, to be adjusted. In this way, the opening width 21 can be adapted to a changed sleeper spacing 22 or to double sleepers.

[0030] In detail, the respective stop device 20 is described based on the Figures 3 and 4 explained. The illustration shows the one in Fig. 1 Left-hand auxiliary drive 12 with the split ball joint 17. The stop device 20 comprises a stop 23, which is arranged on the cylinder body 24. A cantilever 26 with a spindle 27 aligned parallel to the piston rod 25 is attached to the piston rod 25. The spindle 27 is guided through the stop 23. A threaded nut is arranged at the free end of the spindle 27 as a stop element 28, advantageously secured with a lock nut 29. By turning the threaded nut, the starting position of the associated tamping tool 7 and thus the opening width 21 can be adjusted.

[0031] In a further development, a spacer element 30 is mounted on the stop 23 by means of a pivot pin 31. The pivot pin 31 is coupled to an actuator 32, so that the spacer element 30 can be pivoted from a swiveled position to a position between the stop 23 and the stop element 28. In the swiveled position, the spacer element 30 acts as a stop for the stop element 28, thereby reducing the stroke of the hydraulic cylinder. Thus, two different starting positions of the associated tamping tool 7 can be easily set using the spacer element 30. Fig. 4 The distance element 30 is shown with solid lines in the swiveled position and with a dashed line in the swiveled position.

[0032] A variant without an eccentric shaft 14 is in Fig. 5The auxiliary drives 12 are shown in the diagram. Here, the auxiliary drives 12 are mounted directly on the tool carrier 2. Modified hydraulic cylinders are used, which are also configured to generate the vibration. During operation, cyclic vibration movements are superimposed on an auxiliary movement by means of a pulsating control of a servo or proportional valve 33. The respective auxiliary drive 12 is oriented approximately vertically and includes a displacement sensor 34 for detecting a piston stroke. This enables stroke-dependent control of the hydraulic cylinder. The displacement sensor 34 is also used to limit the stroke and thus to determine the opening width 21. In this design, the effective axis 13 and the axis of symmetry 15 of the respective auxiliary drive 12 coincide. During an auxiliary or reset operation, the orientation of the axis 13, 15 changes minimally due to the rotational movement of the associated tamping tool 7.

[0033] A tamping unit 1 for a switch tamping machine or universal tamping machine is in Fig. 6 As shown, each tamping tool 7 comprises two tamping pick holders 8, which can be pivoted by means of swivel drives 35. In this way, each tamping pick 9 can be pivoted upwards separately to avoid a collision with an obstacle when the tamping unit 1 is lowered. In this variant, the respective tamping tool 7 is extended upwards so that the swivel drives 35 can be pivotally mounted on the tamping tool 7. Fig. 6 An eccentric shaft 14 is arranged to generate the vibration. The tamping tools 7 with pivoting tamping picks 9 are also equipped with the in Fig. 5 The hydraulic cylinders shown can be combined.

[0034] A tamping unit 36 ​​for simultaneously tamping several adjacent sleepers 37 of a track 38 is in Fig. 7The diagram shows several tamping units 1 arranged in three rows one behind the other on guide columns 39 of a common assembly frame 4. This assembly frame 4 is slidably mounted on the machine frame of a tamping machine by means of supports 40 oriented transversely to the track 38. The compact design of the tamping units 1 enables this arrangement, in which the tamping picks 9 of adjacent tamping units 1 penetrate the same sleeper bay. The sleeper spacing 22 of the sleepers 37 embedded in the ballast 41 determines the opening width 21 of the tamping units 1. Two tamping units 1 are assigned to each rail 42 of the track 38 per row, so that each row consists of four tamping units 1. In total, the illustrated tamping assembly 36 comprises twelve tamping units 1, which are individually height-adjustable.In a variant not shown, each tamping unit 1 is arranged in its own aggregate frame 4, wherein the aggregate frames 4 are adjustable relative to each other and are mounted on the machine frame of the tamping machine.

[0035] The Figures 8 and 9 show starting positions of the stuffing tools 7 of the in Fig. 7 shown stuffing unit 36. In Fig. 8 The tamping tools 7 are set for tamping under concrete sleepers 43. Fig. 9 Figure 1 shows the starting positions of the tamping tools 7 for under-tamping wooden sleepers 44. The sleeper spacing 22 of the concrete sleepers 43 is greater than the sleeper spacing 22 of the wooden sleepers 44. The starting positions are preferably adjusted by means of the described stop devices 20.

[0036] For example, the spacer elements 30 remain in the extended position for concrete sleepers 43. For tamping wooden sleepers 44, the spacer elements 30 are moved into the stop position, thus reducing the opening widths of the opposing tamping tools 7. Adjusting the respective stop element 28 on the associated spindle 27 serves for fine-tuning. This allows, on the one hand, the maximum possible adjustment range of the internally arranged tamping units 1. On the other hand, the fine-tuning prevents tamping tools 7 of adjacent tamping units 1 from colliding. A fine-tuning process is performed once for adjusting the tamping pick positions on concrete sleepers 43 and on wooden sleepers 44.

[0037] Alternatively, position-dependent control of the auxiliary drives 12 is provided. Each auxiliary drive 12 is assigned a displacement sensor 34 for detecting the piston stroke. During a reset operation, the current position of the respective tamping tool 7 is detected via the displacement sensor 34. The reset operation ends when the predetermined opening width or tamping tool position is reached.

[0038] In hydraulic tamping drives 12, the concrete sleepers 43 and the wooden sleepers 44 are tamped with the same hydraulic pressures, with each tamping unit 1 being connected to a common hydraulic system with a uniform system pressure. The respective tamping tool 7 is reset by simultaneously pressurizing both pressure chambers with the system pressure. For an order cycle, the pressure in the piston-side pressure chamber (larger piston area) is reduced by means of a controlled hydraulic valve. The tamping force results from the pressure difference and the ratio between the larger piston-side area and the smaller rod-shaped ring area. The piston remains hydraulically clamped at all times.

Claims

1. A tamping unit segment (1) for tamping sleepers (37, 43, 44) of a track (38), with tamping tools (7) mounted on a height-adjustable tool carrier (2) opposite one another with respect to a vertical centre plane (6), which are each connected to a squeeze drive (12) for generating a squeezing movement, wherein a lever arm (10) with a connecting part (11) projecting over the centre plane (6) is arranged on each tamping tool (7) and wherein the connecting part (11) of the respective lever arm (10) is connected to the assigned squeeze drive (12), characterized in that the connecting parts (11) and the bearing points (5) are approximately at the same height, resulting in an optimum leverage effect.

2. A tamping unit segment (1) according to claim 1, characterized in that the one lever arm (10) protrudes through a fork-shaped opening of the other lever arm (10).

3. A tamping unit segment (1) according to claim 1 or 2, characterized in that an effecting axis (13) of the respective squeeze drive (12) forms an acute angle (α) with the centre plane (6), in particular an angle (α) of up to 30°.

4. A tamping unit segment (1) according to one of the claims 1 to 3, characterized in that each squeeze drive (12) is connected to an eccentric shaft (14) of a vibration drive.

5. A tamping unit segment (1) according to claim 4, characterized in that equalizing masses (19) are arranged on the eccentric shaft (14).

6. A tamping unit segment (1) according to one of the claims 1 to 3, characterized in that each squeeze drive (12) is set up as a hydraulic cylinder for generating a vibration superimposed on the squeezing movement.

7. A tamping unit segment (1) according to one of the claims 1 to 6, characterized in that each squeeze drive (12) is coupled to a distance sensor (34) to record an actuating distance.

8. A tamping unit segment (1) according to one of the claims 1 to 7, characterized in that each squeeze drive (12) is coupled to an adjustable limit stop device (20) in such a way that a limit stop element (28) can be moved against a limit stop (23) through an actuation of the squeeze drive (12).

9. A tamping unit segment (1) according to claim 8, characterized in that the respective limit stop device (20) comprises a spindle (27) and a limit stop element (28) arranged to rotate thereon.

10. A tamping unit segment (1) according to claim 8 or 9, characterized in that the respective limit stop device (20) comprises an adjustable distance element (30) which can be moved by means of an actuating mechanism (32) from a pivoted-out position to a position between the limit stop (23) and the limit stop element (28).

11. A tamping unit segment (1) according to one of the claims 1 to 10, characterized in that each tamping tool (7) comprises a tamping tine holder (8) with two tamping tines (9) fastened therein.

12. A tamping unit segment (1) according to one of the claims 1 to 11, characterized in that least one tamping tine (9) of the respective tamping tool (7) is arranged in a tamping tine holder (8) that can be tilted upwards.

13. A tamping unit (36) for simultaneous tamping of adjacent sleepers (37, 43, 44) of a track (38), characterized in that a plurality of tamping unit segments (1) according to one of the claims 1 to 12 are arranged one behind the other and that each tamping unit segment (1) in particular is able to be adjusted in height separately by means of an assigned height-adjustment drive (3).

14. A method for operating a tamping unit segment (1) according to one of the claims 1 to 12, characterized in that the tamping tools (7) inserted into a ballast bed during a squeezing process are squeezed by pulling the connecting part (11) of the respective lever arm (10) upwards by means of the assigned squeeze drive (12).

15. A method for operating a tamping unit (36) according to claim 13, characterized in that, with the tamping unit segments (1) arranged one behind the other, a respectively assigned limit stop device (20) is adjusted in at least some of the squeeze drives (12) to adjust to a changed sleeper spacing (22) by moving a distance element (30) between a limit stop (23) and a limit stop element (28) using an actuating mechanism (32).