A tamping device for compacting the underside of track sleepers.

Abstract

The invention relates to a tamping unit (1) for compacting the underside of track sleepers (7), comprising a tamping device (4) with mutually opposed tamping tools (9) pivotably supported on a height-adjustable tool support (5), each tamping tool (9) being connected to a vibration drive (21) via a transmission element (17). In the invention, each transmission element (17) is connected to the assigned tamping tool (9) via a first joint (16) and to a squeeze drive (19) supported on the same tamping tool (9) via a second joint (18). This construction allows a space-saving arrangement of the squeeze drive (19), which results in a compact construction.

Description

[Technical field]

[0001] The invention relates to a tamping unit for compacting the underside of track sleepers, comprising a tamping device with mutually opposed tamping tools pivotably supported on a height-adjustable tool support, each tamping tool being connected to a vibratory drive via a transmission element. [Background technology]

[0002] From AU 304606 C2 a tamping unit as mentioned at the beginning is known. Each tamping device has four tamping tools for simultaneously tamping the undersides of two adjacent sleepers. In this case, each of the two tamping tools is connected to a vibratory drive via a transmission element configured as a pivoting lever. Individual height adjustment of the individual tamping tools is not possible.

[0003] Independently height-adjustable tamping devices for tamping the underside of individual sleepers are disclosed in AU 520267 A1. There, cross-arranged squeeze cylinders are connected to a vibratory drive via a console-like transmission element. The narrow construction thus achieved allows the juxtaposition of several tamping devices to form a simultaneous tamping unit, which can simultaneously tamper the undersides of several sleepers next to each other. Compared to conventional tamping units, the cross-arrangement of squeeze cylinders requires further constructional adaptations so that unfavourable load situations are avoided. Summary of the Invention [Problem to be solved by the invention]

[0004] The object of the present invention is to improve a tamping unit of the type mentioned at the beginning compared to the prior art in such a way that low loads on the unit components and good mass compensation are achieved with a compact construction.

[0005] According to the invention, this problem is solved by the features of the independent claim 1. Advantageous configurations of the invention are described in the dependent claims.

[0006] In the present invention, each transmission element is coupled via a first joint to the assigned tamping tool and via a second joint to the squeeze drive supported on the same tamping tool. Each tamping tool thus forms, together with the assigned squeeze drive and the assigned transmission element, a kinematic system for the squeeze or return movement of the tamping pick arranged on the tamping tool. In this arrangement, the tamping tool is directly supported on the tool support and the assigned transmission element is supported on the tool support via a vibration drive. The transmission element not only serves as an element of the squeeze kinematics but also serves to transmit the vibration movement to the assigned tamping tool. This construction allows a space-saving arrangement of the squeeze drive, which results in a compact construction form of the tamping device. Furthermore, no crossing of the drives is required. The arrangement of all components for force transmission in one common plane reduces the loads and facilitates the compensation of the moved masses.

[0007] In an advantageous refinement, each transmission element is pivotally connected to the vibratory drive via a third joint. This pivotable connection to the vibratory drive provides an additional degree of freedom for optimally positioning each transmission element. In a simpler variant, each transmission element is rigidly connected to the vibratory drive. This can be advantageous, for example, when each tamping tool is assigned its own vibratory drive.

[0008] If the transmission element is pivotally coupled to the assigned vibration drive, advantageously a third joint is arranged between the first and second joints. Due to the leverage effect achieved in this way, the vibrations transmitted to the tamping tool are amplified. Furthermore, the greater distance between the first and second joints facilitates the structural arrangement of each squeeze drive. Furthermore, the vibration load of each squeeze drive is reduced.

[0009] Advantageously, the vibratory drive is configured as an eccentric drive. In tamping units, the eccentric drive constitutes a reliable vibration generator that has been tested for many years. Even in the case of higher reaction forces due to a hard ballast bed, a stable vibration amplitude is maintained during operation. In particular, compared to hydraulic exciters, the eccentric drive offers an efficient operating mode with low energy consumption due to the effective spring mass.

[0010] In a preferred embodiment of this variant, each transmission element is pivotally connected to an eccentric arm supported on an eccentric section of the eccentric shaft of the eccentric drive, thus achieving a pivotal connection of each transmission element to the assigned eccentric drive in a simple manner.

[0011] In an advantageous refinement, each squeeze drive is configured as a hydraulic cylinder with a cylinder axis oriented approximately vertically, which allows a narrow design of the respective tamping device without limiting the squeeze distance.

[0012] Advantageously, in this case, each squeeze cylinder is pivotally connected on the cylinder side to the assigned tamping tool and on the piston rod side to the assigned transmission element. The narrower piston rod leaves more space for arranging the transmission element. Furthermore, this arrangement minimizes the vibration loads of the entire system, since a larger mass part of the squeeze cylinder is located in the vicinity of the assigned pivot support of the tamping tool. The acting mass moment of inertia places only a small mechanical load on the support points.

[0013] In a further refinement, the angle between the axis of each cylinder and the vertical axis during the squeeze operation is at most 20°, in particular at most 10°. In this way, the slim design of the respective tamping device is maintained even during operation. In this case, the support points of the tamping tool, the support points of the squeeze cylinder and the support points of the transmission element are coordinated with one another in such a way that the squeeze cylinder performs only a small pivoting movement during operation.

[0014] Advantageously, each tamping tool has an upper lever arm and a lower lever arm, the lower lever arm being equipped with at least one tamping pick and the upper lever arm being connected to an assigned transmission element, the respective mutually opposing tamping tools forming a tong-like assembly which ensures optimal force transmission and an effective squeezing movement.

[0015] In an advantageous refinement, at least one tamping axe is arranged on an upwardly swivellable tamping axe holder, which allows for efficient processing of switches and crossings. Even during track compaction, the upward swivelling of the individual tamping axes prevents collisions with obstacles present on the track. Advantageously, each tamping tool is provided with two swivellable tamping axe holders for one tamping axe each, so that selectively only one or both tamping axes can be swivelled upward.

[0016] In a refinement of the invention, each tamping device only has two tamping tools for tamping the underside of only one sleeper of the track. In this case, each tamping device has the optimal geometry and dimensions for tamping the underside of one sleeper. For example, all tamping picks are precisely oriented vertically for low penetration resistance during the penetration operation into the ballast bed. The dimensions of the squeeze drives are also optimally adjusted to the squeeze distance and squeeze force to be achieved.

[0017] Advantageously, for high working speeds on a track section, several such tamping devices are arranged one after the other for simultaneously tamping the undersides of adjacent sleepers. By arranging individual tamping devices, efficient and qualitative processing at turnstiles or track crossings can also be carried out with the aid of such tamping units.

[0018] Preferably, the tamping devices arranged one behind the other are arranged on a common unit frame, and each tamping device is height-adjustable individually by means of an assigned height-adjustment drive. This allows a high degree of flexibility when processing switches and track sections. For example, to process a turnout track line, only individual tamping units need to be activated.

[0019] In order to be able to optimally process both the track section and the switches, in one refinement, only some of the tamping devices arranged one behind the other have a tamping pick holder that can be pivoted upwards, and these tamping devices are used when processing the switches. In order to efficiently process the track section, the remaining tamping units are also activated.

[0020] The improved configuration of the tamping unit comprises at least two tamping devices formed in the same structure, which allows synergistic effects during production and maintenance, and also makes it easier to organize different simultaneous tamping units.

[0021] The invention will now be described, by way of example only, with reference to the accompanying drawings, in which: [Brief description of the drawings]

[0022] [Figure 1] FIG. 2 is a schematic front view of a half of a tamping unit. [Diagram 2] FIG. 2 is a schematic side view of a tamping device. [Diagram 3] FIG. 2 is a schematic diagram of a kinematic model of a tamping device. [Figure 4] FIG. 2 is a schematic diagram of a simultaneous tamping unit. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] The tamping unit 1 shown in Fig. 1 comprises a number of unit frames 2 which are supported so as to be laterally movable on a machine frame 3 of a track construction machine, which will not be described in detail. At least one tamping device 4 is arranged on each unit frame 2. Each tamping device 4 comprises a tool support 5 which is height-adjustably guided in a vertical guide of the assigned unit frame 2. The lifting and lowering movement is effected by an assigned height adjustment drive 6.

[0024] During operation, the track construction machine travels on a track with sleepers 7 supported on a ballast bed and rails 8 fastened to the sleepers 7. In this case, the underside of the sleepers 7 is compacted by the tamping unit 1. Usually, the underside of each sleeper 7 is compacted by a number of tamping devices 4 arranged side by side. These tamping devices 4 arranged side by side are advantageously arranged on a pivoting and moving device so as to be pivotable about a yaw axis and movable laterally, thereby enabling positioning on the turnout rail line of the switch. In the tamping unit 1 for simultaneously compacting the undersides of adjacent sleepers 7, a number of tamping devices 4 are arranged side by side (Fig. 4).

[0025] Two tamping tools 9 are pivotably supported on the tool support 5 of each tamping device 4, with their undersides facing each other relative to the sleeper 7 to be tamped. Their pivot axis 10 is oriented transversely to the track. At least one tamping pick 14 is attached to a tamping pick holder 12, 13 on the lower lever arm 11 of each tamping tool 9. During the compaction operation, the pivoting movement of the tamping tools 9 about their respective pivot axes 10 causes a squeezing or return movement of the opposing tamping picks 14.

[0026] The upper lever arm 15 of each tamping tool 9 is connected to a first joint 16 of a transmission element 17. Each transmission element 17 is connected via a second joint 18 to an assigned squeeze drive 19. Furthermore, the transmission element 17 is pivotally connected between the first joint 16 and the second joint 18 via a third joint 20 to a vibration drive 21 (FIG. 2). In a simpler variant, the transmission element 17 is rigidly connected to one element of the vibration drive 21.

[0027] In the illustrated embodiment of the transmission element 17, the rotation axes of the three joints 16, 18, 20 are arranged at the corner points of an isosceles triangle in side view. Each squeeze drive 19 is configured as an approximately vertically oriented hydraulic cylinder with a cylinder body 22 (cylinder tube and cover) and an upwardly directed piston rod 23. At its lower end, each cylinder body 22 is pivotally connected to the assigned tamping tool 9. A pin with a sliding support is arranged on the end side of the piston rod 23. This results in a pivotable connection with the assigned transmission element 17 via the second joint 18.

[0028] Each transmission element 17, in the illustrated embodiment, acts as a lever for transmitting the squeeze force from the respective squeeze drive 19 to the assigned tamping tool 9. In this case, the third joint 20 serves as a central lever joint coupled to the assigned vibration drive 21. The kinematic system consisting of the tamping tool 9, the squeeze drive 19 and the transmission element 17 is thus set in vibration when the vibration drive 21 is activated. For example, the vibration drive 21 is arranged with an electromagnetic actuator. In this case, an armature is set in reciprocating motion in an electromagnetic or magnetic field with a predefined vibration frequency.

[0029] In the illustrated example, the vibration drive 21 is formed as an eccentric drive. In this eccentric drive, the vibration frequency is determined by the rotation speed of the eccentric shaft 24. A number of eccentric sections are arranged on each eccentric shaft 24. For example, a first section with a first eccentricity is located in the middle of two eccentric shaft supports. On both sides of this first section, two divided sections with a second eccentricity are formed. A first eccentric arm 25 is supported on the eccentric first section, which is connected to one of the tamping tools 9 facing each other. A second eccentric arm 25 is supported on both adjacent eccentric divided sections by two supports arranged in a fork shape. This second eccentric arm 25 is connected to the other of the tamping tools 9 facing each other.

[0030] The orientation of both eccentric arms 25 and the rotational position of the eccentric sections relative to one another are selected so that an opposite oscillatory movement with the desired vibration amplitude occurs at the third joint 20 of the connected transmission element 17. The length ratio between the upper lever arm 15 and the lower lever arm 11 of each tamping tool 9 determines, according to the leverage principle, the vibration amplitude effective at the tip of the assigned tamping pick 14.

[0031] 3 shows a schematic representation of the kinematic arrangement of the tamping tools 9 with the corresponding transmission elements 17, squeeze drives 19 and vibration drives 21. The arrangement of the opposing tamping tools 9 is designed symmetrically with respect to an axis of symmetry 26, so that identical eccentricities at the eccentric shafts 24 result in identical vibration amplitudes of the opposing tamping tools 9.

[0032] The approximately vertical orientation of the squeeze drives 19 allows a particularly narrow construction form of each tamping device 4. During the squeeze operation, each squeeze drive 19 performs only a small pivoting movement, during which the angle α between the cylinder axis 27 and the vertical axis 28 remains within a narrow range of maximum 10°, in particular maximum 5°.

[0033] The extension of the piston rod 23 causes a tilting movement of the transmission element 17 about the third joint 20. This causes the first joint 16 to be displaced outward relative to the pivot axis 10. The corresponding displacement distance determines the squeeze distance at the tip of the corresponding tamping pick 14 according to the leverage principle. If the third joint 16 were not present, a tilting movement would take place about the pivot axis of the oscillating drive 21.

[0034] Advantageously, on the lower lever arm 11 of each tamping tool 9 there is arranged an inner tamping pick holder 12 and an outer tamping pick holder 13 for mounting one tamping pick 14 each. The designations inner tamping pick holder 12 and outer tamping pick holder 13 refer to the position of the two tamping devices 4 which can be lowered on either side of the rail 8 (FIG. 1). The tamping pick 14 of the inner tamping pick holder 12 is lowered closer to the rail 8.

[0035] Each tamping pick holder 12, 13 can be swiveled around an axis oriented in the longitudinal direction of the rail by means of its own swiveling drive 29. This allows each tamping pick 14 to be swiveled upwards individually before the tamping device 4 is lowered, in cases where there is no space for penetration between the sleepers 7 and between the rails 8. This is done in particular when compacting the underside of a turnout or crossing rail line as well as a switch or crossing where the actuating device forms an obstacle. In FIG. 1, the position of the tamping pick 14 swiveled upwards is indicated by a dashed line on the left tamping device 4.

[0036] In Fig. 4, a unit frame 2 is shown with three tamping devices 4 arranged one behind the other. This simultaneous unit allows the undersides of three sleepers 7 located directly behind each other to be tamped simultaneously during each tamping operation. By individual support on a common unit frame 2, the tamping devices 4 can also be displaced individually in height. This measure is useful for avoiding collisions with obstacles or for tamping the undersides of double sleepers.

[0037] The invention also includes another tamping unit 1, which can be easily assembled due to the narrow construction of the tamping devices 4. For example, two tamping devices 4 are arranged one after the other on each unit frame 2. In this case, only the front tamping device 4 or the rear tamping device 4 is equipped with an upwardly pivotable tamping pick holder 12, 13. These tamping devices 4 are used in particular at switches. All tamping devices 4 work together for efficient processing of the track section. In this case, the undersides of the two sleepers 7 are simultaneously tamped during each compaction operation.

[0038] In another configuration of the simultaneous unit, an asymmetric tamping device 4 is used in the first or last row in order to achieve a larger squeeze distance. In such an asymmetric tamping device 4, only one of the opposing tamping tools 9, including the squeeze drive 19 and the transmission element 17, is formed in a narrow structural form. In this configuration, 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 adjacent to the rear or front tamping device 4 of the simultaneous unit.

[0039] On the free side of the asymmetric tamping device 4, the lower support of the squeeze drive 19 is pushed outwards. A longer hydraulic cylinder with a larger stroke can thus be used as the squeeze drive 19. The squeeze distance of the assigned tamping tool 9 is thus increased. In this case, the angle α between the cylinder axis 27 and the vertical axis 28 of the longer hydraulic cylinder is greater than 20°, for example 40°.

Claims

1. A tamping unit (1) for compacting the underside of track sleepers (7), comprising a tamping device (4) with opposing tamping tools (9) pivotably supported on a height-adjustable tool support (5), each of said tamping tools (9) being connected to a vibratory drive (21) via a transmission element (17), A tamping unit (1), characterized in that each of the transmission elements (17) is connected to the assigned tamping tool (9) via a first joint (16) and is connected to a squeeze drive (19) supported on the same tamping tool (9) via a second joint (18).

2. 2. Tamping unit (1) according to claim 1, characterized in that each of the transmission elements (17) is pivotally connected to the vibratory drive (21) via a third joint (20).

3. 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. 4. The tamping unit (1) according to claim 1, wherein the vibratory drive (21) is configured as an eccentric drive.

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

6. 2. The tamping unit (1) according to claim 1, characterized in that each squeeze drive (19) is formed as a hydraulic cylinder with a substantially vertically oriented cylinder axis (27).

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

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

9. 2. A tamping unit (1) according to claim 1, characterized in that each tamping tool (9) has an upper lever arm (15) and a lower lever arm (11), the lower lever arm (11) being equipped with at least one tamping pick (14), and the upper lever arm (15) being connected to the assigned transmission element (17).

10. 10. The tamping unit (1) according to claim 9, characterized in that at least one tamping ice axe (14) is arranged on an upwardly pivotable tamping ice axe holder (12, 13).

11. 2. A tamping unit (1) according to claim 1, characterized in that each tamping device (4) comprises only two tamping tools (9) for compacting the underside of only one sleeper (7) of the track.

12. 12. The tamping unit (1) according to claim 11, characterized in that a plurality of tamping devices (4) are arranged one after the other for simultaneously tamping the undersides of adjacent sleepers (7) of the track.

13. 13. The tamping unit according to claim 12, characterized in that the tamping devices (4) arranged one after the other are arranged on one common unit frame (2), and each tamping device (4) is individually height adjustable by means of an assigned height adjustment drive (6).

14. Tamping unit (1) according to claim 12 or 13, characterized in that only a part of the tamping device (4) has an upwardly pivotable tamping ice axe holder (12, 13).

15. Tamping unit (1) according to claim 12, characterized in that at least two tamping devices (4) are formed of the same construction.

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