Tamping unit and method for tamping sleepers of a track

Abstract

The invention relates to a tamping unit (1) for tamping sleepers (37, 43, 44) of a track (38), having tamping tools (7) which are situated opposite one another with respect to a vertical central plane (6), which are mounted on a height-adjustable tool carrier (2), and which are each connected to a feed drive (12) for generating a feed movement, wherein a lever arm (10) having a connection part (11) that projects beyond the central plane (6) is arranged on each tamping tool (7), and wherein the connection part (11) of each lever arm (10) is connected to the associated feed drive (12). This arrangement results in an approximately symmetrical construction of all drive elements, with an optimized load situation during operation.

Description

Description Tamping unit and method for tamping sleepers of a track Technical area

[0001] The invention relates to a tamping unit for tamping sleepers of a track, comprising tamping tools arranged opposite one another with respect to a vertical center plane, mounted on a height-adjustable tool carrier, each of which is connected to a positioning drive for generating a positioning movement. Furthermore, the invention relates to a tamping unit 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 aligned approximately horizontally and, during an auxiliary drive, pushes an upper lever arm of the associated tamping tool outward. In doing so, the lower lever arms of the tamping tools, with their attached tamping tines, are moved toward each other. Using a suitably configured hydraulic control system, an oscillating movement is superimposed on the auxiliary drive movement. A pulsating pressure is applied to a chamber of the hydraulic cylinder. Alternatively, the auxiliary drives can be connected to an eccentric drive for vibration application.

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

[0004] The invention is based on the object of improving a tamping unit of the type mentioned above in such a way that a narrow design is possible and unfavorable loading conditions are avoided. Furthermore, it is an object of the invention to provide a method for operating the corresponding tamping unit.

[0005] According to the invention, these objects are achieved by the features of independent claims 1 and 14. Dependent claims specify advantageous embodiments of the invention.

[0006] A lever arm with a connecting part projecting above the center plane is arranged on each tamping tool, whereby the connecting part of the respective lever arm is connected to the associated auxiliary drive. The center plane divides the tamping unit into two halves, with each half housing the respective tamping tool and the auxiliary drive of the opposite tamping tool. This arrangement results in a nearly symmetrical design of all drive and transmission elements, with an optimized load distribution during operation. Even the interlaced arrangement of the lever arms is possible with appropriately designed connecting parts without disruptive torsional loads. Advantageously, each auxiliary drive is arranged above the tamping tool coupled to the other auxiliary drive. In addition to the slim design, the arrangement according to the invention also offers optimal power transmission from the respective auxiliary drive to the associated tamping tool.

[0007] In a preferred embodiment, one lever arm extends through a forked opening of the other lever arm. In the forked lever arm, both fork ends form the connecting part for connecting to the assigned auxiliary drive. This avoids torsional moments and asymmetrical loads.

[0008] In a further improvement, the effective axis of the respective tilling drive forms an acute angle with the center plane, in particular an angle of up to 30°. The effective axis determines the direction of the force acting from the auxiliary drive on the associated tamping tool. A nearly vertical effective axis promotes a narrow design of the tamping unit and optimal power transmission. The connecting parts and the bearing points on which the tamping tools are mounted on the tool carrier are located at approximately the same height to achieve the best leverage.

[0009] In a preferred variant, each auxiliary drive is connected to an eccentric shaft of a vibration drive. This results in high process reliability because the vibration amplitude determined by the eccentricity of the eccentric shaft is maintained even in the face of strong counterforces from a contaminated ballast bed. The auxiliary drives transmit the vibration to the assigned tamping tools, thus optimizing penetration into the ballast bed and ballast compaction under the sleepers.

[0010] It is advantageous to install balancing masses on the eccentric shaft. These compensate for vertical vibrations that may arise from the vibrating masses of the auxiliary drives. However, vertical vibrations can also be used specifically to improve penetration into the ballast bed.

[0011] In an alternative variant, each auxiliary drive is configured as a hydraulic cylinder to generate a vibration superimposed on the order movement. The respective hydraulic cylinder is mounted directly on the tool carrier and is controlled via a servo or proportional valve.

[0012] Advantageously, each auxiliary drive is coupled to a travel sensor to record the travel. This allows the auxiliary drives to be controlled in a travel-dependent manner. This allows for easy adaptation to different sleeper spacings or to double sleepers by pre-setting the opening width of the tamping tools before they penetrate the The odometer is also used to generate hydraulic vibrations.

[0013] In a further improvement, each auxiliary drive is coupled to an adjustable stop device such that, upon resetting the respective tamping tool, a stop element can be moved against a stop. In this way, the resetting of the tamping tools is terminated by the stop device.

[0014] In an advantageous further development, the respective stop device comprises a spindle and a stop element rotatably mounted thereon. This allows the opening width of the tamping tools to be precisely adjusted in the retracted state.

[0015] In a further improvement, the respective stop device comprises an adjustable spacer element, which can be moved by means of an actuator from a pivoted position to a position between the stop and the stop element. Depending on the position of the spacer element, different opening widths can be adjusted to accommodate double sleepers or changed sleeper pitches.

[0016] In a simple version, each tamping tool includes a tamping pick holder with two tamping picks attached. This allows track sections without switches or crossings to be tamped efficiently and with high quality.

[0017] In another advantageous embodiment, at least one tamping tine of the respective tamping tool is mounted in a pivoting tamping tine holder. At switches and crossings, as well as at track obstacles, the corresponding tamping tines can be pivoted upwards to avoid collisions with rails, sleepers, or track obstacles. The other tamping tines of the respective tamping unit can still be inserted into and positioned in free spaces at a switch or crossing.

[0018] In a tamping unit to achieve a higher performance, it is advisable to arrange several of the described tamping units one behind the other for the simultaneous tamping of adjacent sleepers of the track, whereby in particular each tamping unit is The height of the tamping units can be adjusted separately using a dedicated height actuator. The snug-fitting tamping units also allow for tamping of adjacent sleepers with small sleeper spacing.

[0019] In the method according to the invention for operating the described tamping unit, the tamping tools immersed in a ballast bed are tamped during a tamping process by pulling the connecting part of the respective lever arm upward using the associated tamping drive. This tamping movement occurs with the respective tamping drive exerting optimal force on the associated tamping tool. If an eccentric drive is present, a reliable transmission of vibration to the tamping tools is also ensured.

[0020] In the method for operating a tamping unit with several tamping units arranged one behind the other, an associated stop device is adjusted for at least some of the auxiliary drives to adapt to a changed sleeper pitch. An actuator moves a spacer element between a stop and a stop element. This allows for a rapid adjustment of the starting positions of the tamping picks, for example, at a transition between concrete and wooden sleepers. Short description of the drawings

[0021] The invention is explained below by way of example with reference to the accompanying figures. They show schematically: Fig. 1 Tamping unit with eccentric shaft in a side view Fig. 2 Tamping unit according to Fig. 1 in a front view Fig. 3 Side cylinder in a front view Fig. 4 Side cylinder according to Fig. 3 in a side view Fig. 5 Tamping unit without eccentric shaft Fig. 6 Tamping unit with swiveling picks Fig. 7 Row tamping unit Fig. 8 Row tamping unit for tamping concrete sleepers Fig. 9 Row tamping unit for tamping wooden sleepers Description of the embodiments

[0022] Figures 1 and 2 show a tamping unit 1 with a tool carrier 2, which is arranged in an assembly frame 4 so that its height can be adjusted by means of a height adjustment drive 3. The assembly frame 4 is preferably arranged displaceably and rotatably on a machine frame of a tamping machine. Tamping tools 7 are mounted opposite one another with respect to a vertical center plane 6 at two bearing points 5 of the tool carrier 2. Each tamping tool 7 comprises a tamping pick holder 8 in which two tamping picks 9 are fastened side by side. According to the invention, a lever arm 10 of each tamping tool 7 projects above the center plane 6 with a connecting part 11. An associated auxiliary drive 12 is connected to this connecting part 11. The connecting part 11 is designed, for example, as a joint eye and forms a pivot joint with a fork head of the auxiliary drive 12.

[0023] In the illustrated embodiment, the connecting parts 11 and the bearing points 5 are located at approximately the same height, resulting in an optimal leverage effect. The auxiliary drives 12 are designed as hydraulic cylinders (e.g., 80 mm piston diameter and 60 mm rod diameter) and are aligned approximately vertically upwards. Electric linear drives can also be used as auxiliary drives 12. Preferably, an effective axis 13 of the auxiliary drive 12 forms an acute angle a with the center plane 6, in particular in a range from 0° to 30°, in particular from 1° to 20°, in particular from 5° to 15°. This results in improved power transmission from the auxiliary drives 12 to the lever arms 10 as the specified ranges become increasingly narrower.

[0024] The invention also encompasses 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 directed downwards. In another variant, the bearing points 5 are arranged in the lower region of the tool carrier 2, and the lever arms 10 are directed upwards so that the auxiliary drives 12 can be aligned downwards.

[0025] The auxiliary drives 12 are advantageously mounted on a common eccentric shaft 14. Between two bearing points of the eccentric shaft 14, a central shaft section with a first eccentricity is formed, and on either side of this, two shaft sections with a second eccentricity are formed. One of the two auxiliary drives 12 comprises a joint head 16 arranged 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, split joint head 17. With this split joint head 17, the auxiliary drive 12 is mounted on the shaft sections with the second eccentricity. The effective axis 13 encloses an angle a of, for example, 10° with the center plane 6, so that optimal power transmission to the lever arms 10 occurs with sufficient freedom of movement of the auxiliary drives 12.

[0026] 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 speed of 35 revolutions per second results in a vibration frequency of 35 Hz. The vibration frequency can be adjusted by changing the speed. For example, the vibration frequency is increased during a penetration process of the tamping tines 9 (e.g., 45 Hz). To reduce noise emissions and vibration stress, the speed of the rotary drive 18 is reduced when the tamping tines 9 are not in the ballast bed. An electric rotary drive 18 is particularly suitable for quickly adjusting the vibration frequency.

[0027] The angular positions of the two eccentricities are coordinated so that the tamping tools 7 can be set into vibration in opposite directions. To avoid vertical vibrations, the oscillating masses of the auxiliary drives 12 and the lever arms 10 are balanced by balancing masses 19 on the eccentric shaft 14. Both eccentricities are, for example, 2 mm, which results in a lever ratio (e.g., 1:2.3). of the respective tamping tool 7 results in a resulting vibration amplitude at the end of the associated tamping pick 9 (e.g. 4.6 mm).

[0028] 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 tines 9 penetrate into a ballast bed to be adjusted. This allows the opening width 21 to be adjusted to a changed sleeper pitch 22 or to double sleepers.

[0029] The respective stop device 20 is explained in detail with reference to Figures 3 and 4. Shown is the auxiliary drive 12 on the left in Fig. 1 with the split joint head 17. The stop device 20 comprises a stop 23 arranged on the cylinder body 24. A boom 26 with a spindle 27 aligned parallel to the piston rod 25 is attached to the piston rod 25. The spindle 27 is guided by the stop 23. At the free end of the spindle 27, a threaded nut is arranged 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 is 7 and thus the opening width 21 adjustable.

[0030] 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 pivoted-out position into a position between the stop 23 and the stop element 28. In the pivoted-in 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. In Fig. 4, the spacer element 30 is shown with solid lines in the pivoted-in position and with a dash-dotted line in the pivoted-out position.

[0031] A variant without eccentric shaft 14 is shown in Fig. 5. Here, the positioning drives 12 are mounted directly on the tool carrier 2. Modified hydraulic cylinders are used, which are also designed to generate the vibration. During operation, a positioning movement is Pulsating control of a servo or proportional valve 33 superimposes cyclical vibration movements. The respective auxiliary drive 12 is aligned approximately vertically and includes a displacement sensor 34 for detecting the piston travel. This enables travel-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 symmetry axis 15 of the respective auxiliary drive 12 coincide. During a positioning or resetting process, the orientation of the axis 13, 15 changes minimally due to the rotary movement of the associated tamping tool 7.

[0032] A tamping unit 1 for a switch tamping machine or universal tamping machine is shown in Fig. 6. Each tamping tool 7 comprises two tamping tine holders 8, which can be pivoted by means of pivot drives 35. In this way, each tamping tine 9 can be pivoted upwards separately to avoid a collision with an obstacle when lowering the tamping unit 1. In this variant, the respective tamping tool 7 is extended upwards so that the pivot drives 35 can be articulated on the tamping tool 7. In Fig. 6, an eccentric shaft 14 is arranged to generate the vibration. The tamping tools 7 with upwardly pivoting tamping tines 9 can also be combined with the hydraulic cylinders shown in Fig. 5.

[0033] A tamping unit 36 ​​for the simultaneous tamping of several adjacent sleepers 37 of a track 38 is shown in Fig. 7. Here, several tamping units 1 are guided in three rows one behind the other on guide columns 39 of a common unit frame 4. This unit frame 4 is slidably arranged on the machine frame of a tamping machine by means of supports 40 aligned 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 immerse in the same sleeper compartment. The sleeper pitch 22 (sleeper spacing) of the sleepers 37 stored in the ballast 41 determines the opening width 21 of the tamping units 1. Each rail 42 of the track 38 is assigned two tamping units 1 per row, so that each row consists of four tamping units 1. In total, the illustrated tamping unit 36 ​​comprises twelve tamping units 1, each of which is separately height-adjustable. In a variant not shown, each tamping unit 1 is arranged in its own unit frame 4, with the unit frames 4 being mounted on the machine frame of the tamping machine so that they are adjustable relative to one another.

[0034] Figures 8 and 9 show the initial positions of the tamping tools 7 of the tamping unit 36 ​​shown in Fig. 7. In Fig. 8, the tamping tools 7 are set for tamping concrete sleepers 43. Fig. 9 shows the initial positions of the tamping tools 7 for 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 adjustment of the initial positions is preferably carried out by means of the described stop devices 20.

[0035] For example, the spacer elements 30 remain in the swiveled-out position for concrete sleepers 43. For tamping wooden sleepers 44, the spacer elements 30 are moved into the stop position, reducing the opening widths of the opposing tamping tools 7. Adjusting the respective stop element 28 on the associated spindle 27 serves for fine adjustment. This allows, on the one hand, the maximum possible adjustment path for the internally arranged tamping units 1. On the other hand, the fine adjustment prevents tamping tools 7 of adjacent tamping units 1 from colliding. A fine adjustment process is performed once for each adjustment of the tamping tool positions on concrete sleepers 43 and on wooden sleepers 44.

[0036] Alternatively, a position-dependent control of the auxiliary drives 12 is provided. Each auxiliary drive 12 is assigned a position sensor 34 to detect the piston stroke. During a reset process, the current position of the respective tamping tool 7 is detected via the position sensor 34. The reset process ends when the specified opening width or tamping tool position is reached.

[0037] With hydraulic auxiliary 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 is connected. A reset process of the respective tamping tool 7 occurs by simultaneously applying system pressure to both pressure chambers. For an ordering process, the pressure in the piston-side pressure chamber (larger piston area) is reduced by means of a controlled hydraulic valve. The actuating force results from the pressure difference and the ratio between the larger piston-side piston area and the smaller rod-shaped ring area. The piston always remains hydraulically clamped.

Claims

Patent claims 1. Tamping unit (1) for tamping sleepers (37, 43, 44) of a track (38), with tamping tools (7) which are opposite one another with respect to a vertical center plane (6) and mounted on a height-adjustable tool carrier (2), each of which is connected to an adjusting drive (12) for generating an adjusting movement, characterized in that a lever arm (10) with a connecting part (11) projecting above the center plane (6) is arranged on each tamping tool (7), and that the connecting part (11) of the respective lever arm (10) is connected to the associated adjusting drive (12).

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

3. Tamping unit (1) according to claim 1 or 2, characterized in that an effective axis (13) of the respective ordering drive (12) encloses an acute angle (α) with the center plane (6), in particular an angle (α) of up to 30°.

4. Tamping unit (1) according to one of claims 1 to 3, characterized in that each auxiliary drive (12) is connected to an eccentric shaft (14) of a vibration drive.

5. Stuffing unit (1) according to claim 4, characterized in that balancing masses (19) are arranged on the eccentric shaft (14).

6. Tamping unit (1) according to one of claims 1 to 3, characterized in that each auxiliary drive (12) is designed as a hydraulic cylinder for generating a vibration superimposed on the tilling movement.

7. Tamping unit (1) according to one of claims 1 to 6, characterized in that each auxiliary drive (12) is coupled to a travel measuring device (34) for detecting a travel path.

8. Stuffing unit (1) according to one of claims 1 to 7, characterized in that each auxiliary drive (12) is coupled to an adjustable stop device (20) in such a way that a stop element (28) can be moved against a stop (23) by actuating the auxiliary drive (12).

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

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

11. Tamping unit (1) according to one of claims 1 to 10, characterized in that each tamping tool (7) comprises a tamping pick holder (8) with two tamping picks (9) fastened therein.

12. Tamping unit (1) according to one of claims 1 to 11, characterized in that at least one tamping pick (9) of the respective tamping tool (7) is arranged in an upwardly pivotable tamping pick holder (8).

13. Tamping unit (36) for the simultaneous tamping of adjacent sleepers (37, 43, 44) of a track (38), characterized in that several tamping units (1) according to one of claims 1 to 12 are arranged one behind the other and that in particular each tamping unit (1) is separately adjustable in height by means of an associated height adjusting drive (3).

14. Method for operating a tamping unit (1) according to one of claims 1 to 12, characterized in that during a tamping process, the tamping tools (7) immersed in a ballast bed are tamped by the The connecting part (11) of the respective lever arm (10) is pulled upwards by means of the associated auxiliary drive (12).

15. Method for operating a tamping unit (36) according to claim 13, characterized in that in the tamping units (1) arranged one behind the other, in order to adapt to a changed sleeper pitch (22), at least in some of the auxiliary drives (12) a respectively assigned stop device (20) is adjusted by moving a spacer element (30) between a stop (23) and a stop element (28) by means of an actuator drive (32).

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