Stuffing unit for stuffing under sleepers of a track

Description

Technical field

[0001] The invention relates to a tamping unit for tamping under the sleepers of a track, comprising a tamping unit with opposing tamping tools pivotably mounted on a height-adjustable tool carrier, wherein the respective tamping tool is coupled to a vibration drive via a transmission element. State of the art

[0002] A tamping unit of this type is known from AT 304606 B. Each tamping unit comprises four tamping tools for simultaneously tamping two adjacent sleepers. Two tamping tools are coupled to a vibratory drive via a transmission element designed as a pivot lever. Separate height adjustment of individual tamping tools is not possible.

[0003] AT 520267 A1 discloses independently height-adjustable tamping units for tamping individual sleepers, in which staggered auxiliary cylinders are connected to a vibratory drive via console-like transmission elements. The resulting narrow design 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 necessitates further design modifications to avoid unfavorable load conditions. Description of the invention

[0004] The invention is based on the objective of improving a stuffing unit of the type mentioned above compared to the prior art in such a way that a low load on the unit components and good mass balance are achieved in a compact design.

[0005] According to the invention, this problem is solved by the features of independent claim 1. Dependent claims specify advantageous embodiments of the invention.

[0006] In this arrangement, each transmission element is connected to the associated tamping tool via a first joint and to an auxiliary drive supported on the same tamping tool via a second joint. Thus, the tamping tool, its associated auxiliary drive, and the associated transmission element form a kinematic system that enables the tamping pick mounted on the tamping tool to move or return to its restoring position. In this arrangement, the tamping tool is supported directly on the tool carrier, while the associated transmission element is supported via the vibration drive. The transmission element serves both as part of the tamping kinematics and as a means of transmitting the vibration movement to the associated tamping tool. This design allows for a space-saving arrangement of the auxiliary drives, resulting in a compact tamping unit. Furthermore, no angular connection of the drives is required.Arranging all force-transmitting components in a common plane results in low loads and promotes a balance of the moving masses.

[0007] In a further advantageous design, the respective transmission element is connected to the vibration drive via a third joint. This articulated connection to the vibration drive creates an additional degree of freedom for the optimal positioning of the respective transmission element. In a simpler version, the respective transmission element is rigidly connected to the vibration drive. This can be useful, for example, if each tamping tool has its own vibration drive.

[0008] When connecting the transmission element to the associated vibratory drive via a joint, the third joint is advantageously positioned between the first and second joints. The resulting leverage effect amplifies the vibration transmitted to the tamping tool. Furthermore, a greater distance between the first and second joints simplifies the structural arrangement of the respective auxiliary drive. This also reduces the vibration load on the auxiliary drive.

[0009] Advantageously, the vibratory drive is designed as an eccentric drive. In tamping units, the eccentric drive represents a reliable and long-proven method for generating vibration. Even with significant counterforces resulting from a hard ballast bed, a stable vibration amplitude is maintained during operation. Compared to hydraulic vibratory generators, in particular, an eccentric drive offers efficient operation with low energy consumption due to its effective flywheel mass.

[0010] In a preferred embodiment of this variant, each transmission element is pivotally connected to an eccentric arm mounted on an eccentric section of an eccentric shaft of the eccentric drive. In this way, a pivotal connection of the respective transmission element to the associated eccentric drive is achieved using simple means.

[0011] In a further advantageous embodiment, the respective auxiliary drive is designed as a hydraulic cylinder with an almost vertically oriented cylinder axis. This vertical orientation of the auxiliary drives results in a slim design for the respective tamping unit, without restricting the auxiliary travel.

[0012] In this arrangement, each auxiliary cylinder is logically articulated to the associated tamping tool on the cylinder side and to the associated transmission element on the piston rod side. The narrower piston rod allows more space for the transmission element. Furthermore, this arrangement minimizes the vibration load on the overall system because the greater mass of the auxiliary cylinder is located near the pivot bearing of the associated tamping tool. The resulting moment of inertia leads to only minimal mechanical stress on the bearing points.

[0013] In a further improvement, the angle between the respective cylinder axis and a vertical axis during an adjustment process is a maximum of 20°, and in particular a maximum of 10°. This ensures that the slim design of the respective tamping unit is maintained even during operation. The bearing points of the tamping tools, the adjustment cylinders, and the transmission elements are coordinated so that the adjustment cylinders only perform minimal pivoting movements during activation.

[0014] The respective tamping tool advantageously has an upper lever arm and a lower lever arm, the lower lever arm comprising at least one tamping pick and the upper lever arm being connected to the associated transmission element. Opposing tamping tools form a pincer-like arrangement, ensuring optimal force transmission and effective tamping action.

[0015] In a beneficial further development, at least one tamping pick is arranged in an upwardly pivoting tamping pick holder. This enables efficient tamping of turnouts and crossings. When tamping track sections, the upward pivoting of individual tamping picks also prevents collisions with obstacles in the track. Ideally, each tamping tool includes two pivoting tamping pick holders, each for one tamping pick, so that either one or both tamping picks can be pivoted upwards.

[0016] In a further development of the invention, each tamping unit comprises only two tamping tools for tamping under a single track sleeper. Each tamping unit has an optimal geometry and dimensions for tamping under a sleeper. For example, all tamping picks are precisely vertically aligned to minimize penetration resistance during immersion into the ballast. The dimensions of the actuating drives are also optimally matched to the required actuating travel and forces.

[0017] Advantageously, for high working speeds on a track, several such tamping units are arranged one behind the other to simultaneously tamp adjacent sleepers. The arrangement of separate tamping units also allows for efficient and high-quality work in turnouts or track crossings with such a tamping unit.

[0018] Preferably, the tamping units arranged in series are housed in a common frame, with each tamping unit being separately height-adjustable by means of an associated height-adjusting drive. This allows for high flexibility when working on turnouts and track sections. For example, only individual tamping units are activated to work on a diverging track section.

[0019] To enable optimal processing of both track sections and turnouts, a further development features only some of the tamping units arranged in series with upward-pivoting tamping pick holders. These tamping units are used for turnout processing. For efficient processing of track sections, the remaining tamping units are also activated.

[0020] An improved version of the tamping unit comprises at least two identical tamping units. This results in synergies in manufacturing and maintenance. Furthermore, combining different series of tamping units is easily accomplished. Brief description of the drawings

[0021] The invention is explained below by way of example with reference to the accompanying figures. These show, in schematic representation: Fig. 1 Half of the tamping unit in a front view. Fig. 2 Tamping unit in a side view. Fig. 3 Kinematic model of a tamping unit. Fig. 4 In-line tamping unit. Description of the embodiments

[0022] The in Fig. 1 The illustrated tamping unit 1 comprises several unit frames 2, which are laterally displaceable relative to a machine frame 3 of a track construction machine (not described in detail). At least one tamping unit 4 is arranged in each unit frame 2. Each tamping unit 4 includes a tool carrier 5, which is height-adjustable and guided in vertical guides of the associated unit frame 2. Lowering and raising movements are effected by an associated height-adjusting drive 6.

[0023] During operation, the track construction machine travels along a track with sleepers 7 supported on a ballast bed and rails 8 attached to them. The sleepers 7 are tamped by the tamping unit 1. Typically, each sleeper 7 is tamped by several tamping units 4 arranged side by side. These tamping units 4 are advantageously rotatable about a vertical axis and laterally displaceable in a rotating and shifting device to allow positioning over a diverging track of a turnout. In a tamping unit 1 for simultaneously tamping adjacent sleepers 7, several tamping units 4 are arranged one behind the other ( Fig. 4 ).

[0024] On the tool carrier 5 of the respective tamping unit 4, two tamping tools 9 opposite each other are pivotably mounted with respect to a sleeper 7 to be tamped. The respective pivot axis 10 is aligned transversely to the track. At least one tamping pick 14 is attached to a lower lever arm 11 of the respective tamping tool 9 in a tamping pick holder 12, 13. Pivoting movements of the tamping tools 9 about the respective pivot axis 10 cause advancing movements or return movements of the opposite tamping picks 14 during a tamping operation.

[0025] An upper lever arm 15 of the respective tamping tool 9 is connected to a first joint 16 of a transmission element 17. The respective transmission element 17 is connected to an associated auxiliary drive 19 via a second joint 18. Furthermore, the transmission element 17 is articulated between the first and second joints 16, 18 via a third joint 20 to a vibratory drive 21. Fig. 2 In a simpler version, the transmission element 17 is rigidly connected to an element of the vibration drive 21.

[0026] In the illustrated embodiment of the transmission element 17, the axes of rotation of the three joints 16, 18, 20 are arranged at the vertices of an isosceles triangle in the side view. The respective auxiliary drive 19 is designed as an approximately vertically oriented hydraulic cylinder with a cylinder body 22 (cylinder tube and cover) and an upwardly directed piston rod 23. The respective cylinder body 22 is pivotally connected at its lower end to the associated tamping tool 9. A bolt with a sliding bearing is arranged at the end of the piston rod 23. This provides a pivotal connection to the associated transmission element 17 via the second joint 18.

[0027] In the illustrated configuration, the respective transmission element 17 serves as a lever to transmit an assisting force from the respective assisting drive 19 to the associated tamping tool 9. The third joint 20 functions as a central lever joint, which is connected to the associated vibratory drive 21. In this way, when the vibratory drive 21 is active, the kinematic system consisting of the tamping tool 9, the assisting drive 19, and the transmission element 17 is set into vibration. For example, a vibratory drive 21 is arranged with an electromagnetic actuator. In this case, an armature is moved back and forth within an electromagnetic or magnetic field at a vibration frequency.

[0028] In the illustrated example, the vibratory drive 21 is designed as an eccentric drive. In an eccentric drive, the rotational speed of an eccentric shaft 24 determines the vibration frequency. Several eccentric sections are arranged on the respective eccentric shaft 24. For example, a first section with a first eccentricity is located centrally between two eccentric shaft bearings. On either side of this, two subsections with a second eccentricity are formed. A first eccentric arm 25 is mounted on the first eccentric section and is coupled to one of the opposing tamping tools 9. A second eccentric arm 25 is mounted on the two adjacent eccentric subsections by means of two fork-shaped bearings. This second eccentric arm 25 is coupled to the other of the two opposing tamping tools 9.

[0029] The alignment of the two eccentric arms 25 and the rotational position of the eccentric sections relative to each other are chosen such that opposing vibration movements with desired vibration amplitudes occur in the third joints 20 of the connected transmission elements 17. According to the lever principle, the length ratio of the upper and lower lever arms 11, 15 of the respective tamping tool 9 determines the vibration amplitude effective at the tip of the associated tamping pick 14.

[0030] In Fig. 3 The kinematic arrangement of a tamping tool 9 with the associated transmission element 17, the auxiliary drive 19, and the vibration drive 21 is shown schematically. The arrangement of the opposing tamping tool 9 is symmetrical about the axis of symmetry 26. This results in equal eccentricities on the eccentric shaft 24 and equal vibration amplitudes for the opposing tamping tools 9.

[0031] The near-vertical orientation of the adjusting drives 19 enables a particularly narrow design for the respective tamping unit 4. During an adjusting operation, the respective adjusting drive 19 performs only a small pivoting movement. An angle α between the cylinder axis 27 and a vertical axis 28 remains within a narrow range of at most 10°, and in particular at most 5°, during this movement.

[0032] Extending the piston rod 23 causes the transmission element 17 to tilt about the third joint 20, thereby displacing the first joint 16 outwards relative to the pivot axis 10. According to the lever principle, the corresponding displacement determines the travel distance at the tip of the associated tamping pick 14. If the third joint 16 is absent, the tilting movement occurs about a rotational axis of the vibratory drive 21.

[0033] Advantageously, an inner tamping pick holder 12 and an outer tamping pick holder 13 for attaching a tamping pick 14 each are arranged on the lower lever arm 11 of the respective tamping tool 9. The designations inner tamping pick holder 12 and outer tamping pick holder 13 refer to the position of two tamping units 4 that can be lowered on either side of a rail 8 ( Fig. 1 The tamping picks 14 of the inner tamping pick holders 12 are lowered closer to the rail 8.

[0034] Each tamping pick holder 12, 13 is pivotable about an axis aligned with the longitudinal direction of the rail by means of its own pivoting drive 29. This allows each tamping pick 14 to be pivoted upwards separately before the tamping unit 4 is lowered, if there is no space for insertion between the sleepers 7 and rails 8. This occurs particularly when tamping under turnouts or crossings, where diverging or intersecting track sections and control devices present obstacles. Fig. 1 The positions of the raised tamping picks 14 on the left tamping unit 4 are shown with dotted lines.

[0035] In Fig. 4Figure 2 shows an aggregate frame with three tamping units 4 arranged in a row. With this series-unit design, three adjacent sleepers 7 can be tamped simultaneously in each tamping operation. Due to their separate mounting within the common aggregate frame 2, the tamping units 4 can also be individually adjusted vertically. This feature is useful for avoiding collisions with obstacles or for tamping double sleepers.

[0036] The invention comprises further tamping units 1 which can be easily assembled due to the narrow design of the tamping units 4. For example, two tamping units 4 are arranged one behind the other in the respective unit frame 2, with only the front or the rear tamping unit 4 comprising upwardly pivoting tamping pick holders 12, 13. These tamping units 4 are used particularly in turnouts. All tamping units 4 together serve to efficiently process a section of track, with two sleepers 7 being tamped simultaneously in each tamping operation.

[0037] In another embodiment of a row unit, asymmetric tamping units 4 are used in the front or rear row to achieve larger adjustment strokes. In such an asymmetric tamping unit 4, only one of the opposing tamping tools 9, including the adjustment drive 19 and transmission element 17, is designed with a narrow profile. Here, the angle α between the cylinder axis 27 and the vertical axis 28 is, for example, a maximum of 5°. This applies to the side bordering the rear or front tamping units 4 of the row unit.

[0038] On the free side of the asymmetrical tamping unit 4, the lower bearing of the auxiliary drive 19 is moved outwards. Consequently, a longer hydraulic cylinder with a greater stroke can be used as the auxiliary drive 19. This increases the adjustment travel of the associated tamping tool 9. The angle α between the cylinder axis 27 of the longer hydraulic cylinder and the vertical axis 28 is greater than 20°, for example, 40°.

Claims

1. A tamping unit (1) for tamping sleepers (7) of a track, comprising a tamping unit segment (4) with opposing tamping tools (9) connected with squeezing drives (19), tiltably mounted directly on a height-adjustable tool carrier (5), with the respective tamping tool (9) being coupled with a vibration drive (21) arranged on the tool carrier (5) via a transmission element (17), characterized in that the respective transmission element (17) which is connected with the vibration drive (21) is connected with the assigned tamping tool (9) via a first joint (16) and with the squeezing drive (19) supported on the same tamping tool (9) via a second joint (18).

2. A tamping unit (1) according to claim 1, characterized in that the respective transmission element (17) is linked to the vibration drive (21) via a third joint (20).

3. A tamping unit (1) according to claim 2, characterized in that the third joint (20) is arranged between the first joint (16) and the second joint (18).

4. A tamping unit (1) according to one of the claims 1 to 3, characterized in that the vibration drive (21) is designed as an eccentric drive.

5. A tamping unit (1) according to claim 4, characterized in that each transmission element (17) is connected with an eccentric arm (25) mounted on an eccentric section of an eccentric shaft (24) of the eccentric drive in an articulated manner.

6. A tamping unit (1) according to one of the claims 1 to 5, characterized in that the respective squeezing drive (19) is designed as a hydraulic cylinder with an approximately vertically aligned cylinder axis (27).

7. A tamping unit (1) according to claim 6, characterized in that each squeezing cylinder (19) is linked to the assigned tamping tool (9) on the cylinder side and to the assigned transmission element (17) on the piston rod side.

8. A tamping unit (1) according to claim 6 or 7, characterized in that an angle (α) between the respective cylinder axis (27) and a vertical axis (28) is at most 20°, in particular at most 10°, during a squeezing process.

9. A tamping unit (1) according to one of the claims 1 to 8, characterized in that the respective tamping tool (9) has an upper lever arm (15) and a lower lever arm (11), that the lower lever arm (11) comprises at least one tamping tine (14), and that the upper lever arm (15) is connected with the assigned transmission element (17).

10. A tamping unit (1) according to claim 9, characterized in that at least one tamping tine (14) is arranged in a tamping tine support (12, 13) that can be tilted upwards.

11. A tamping unit (1) according to one of the claims 1 to 10, characterized in that the respective tamping unit segment (4) comprises only two tamping tools (9) for tamping a single sleeper (7) of the track.

12. A tamping unit (1) according to claim 11, characterized in that several tamping unit segments (4) are arranged one behind the other for the simultaneous tamping of adjacent sleepers (7) of the track.

13. A tamping unit according to claim 12, characterized in that the tamping unit segments (4) arranged one behind the other are arranged in a shared tamping unit frame (2) and that each tamping unit segment (4) is height-adjustable separately by means of an assigned height-adjustment drive (6).

14. A tamping unit (1) according to claim 12 or 13, characterized in that only some of the tamping unit segments (4) have tamping tine supports (12, 13) that can be tilted upwards.

15. A track tamping machine (1) according to one of the claims 12 to 14, characterized in that at least two tamping unit segments (4) are of identical design.