Tamping machine for tamping sleepers of a track

Abstract

The invention relates to a tamping machine (1) for tamping sleepers of a track (2), said tamping machine comprising: a machine frame (14) that can be moved on rail bogies (9) and extends in the longitudinal direction of the tamping machine; and a satellite (3) that is located between the rail bogies (9) and can be moved on the track (2) between the rail bogies (9) via a bogie (10) and a traction drive (F). The satellite is connected to the machine frame (14) via a satellite longitudinal guide (18) so as to be guided by same and has, between the bogie (10) and the satellite longitudinal guide (18), a tamping unit (5) that can be adjusted in height with respect to the satellite (3) and a track lifting / aligning unit (7). In order to reduce the required drive power of the tamping machine (1) and to create an increase in energy efficiency, according to the invention a hydraulic regenerative brake (B) that counteracts the traction drive (F) is assigned to the satellites (3).

Description

Technical area

[0001] The invention relates to a tamping machine for tamping sleepers of a track, with a machine frame which is movable on rail bogies and extends in the longitudinal direction of the tamping machine, and a satellite which is arranged between the rail bogies and which can be moved on the track between the rail bogies via a bogie and a travel drive, which is connected to the machine frame via a satellite longitudinal guide and which has a tamping unit which is height-adjustable with respect to the satellite and a track lifting and straightening unit between the bogie and the satellite longitudinal guide. State of the art

[0002] A tamping machine of the type described above is disclosed in EP1 387003A2. Such tamping machines operate continuously with tamping / working satellites (satellites for short). The tamping machine travels at a constant speed during operation, while the integrated satellite, with tamping units, lifting and straightening equipment, and measuring carriage, moves intermittently from tamping area to tamping area, straightening the track and tamping the sleepers.

[0003] Such a continuously moving tamping machine is known, for example, from US Pat. No. 6,705,232. The advantage of this type of tamping machine is that the main machine, with its significantly larger mass, does not have to be stopped and then accelerated again for each sleeper that needs to be tamped. This increases the machine's working speed compared to cyclically operating machines and also reduces the accelerations acting on the operator. The cyclical advance from sleeper area to sleeper area is limited to the satellite carrying the working units, which is designed to be longitudinally displaceable relative to the main frame of the machine. Nevertheless, the satellite mass amounts to approximately 1 / 4 to 1 / 3 of the total machine mass. Such a machine is also shown in AT401943B.

[0004] Tamping units fix the position of a track during maintenance work. This is done using tamping tools, so-called tamping picks, which penetrate the ballast next to the sleepers and compact the ballast beneath the sleepers using a linear closing movement superimposed by a compaction vibration.

[0005] The movements of a tamping unit include the vertical insertion of the tamping tines into the ballast, the tamping movement in which the tamping tine ends are brought together, and the superimposed dynamic vibration that causes the actual compaction of the ballast grains. For the tamping movement, it is common to use hydraulic cylinders connected via connecting rods to a vibration shaft with eccentricity, which superimposes the vibratory oscillation on the tamping movement (AT 369 455 B). These vibration shafts and connecting rods are mounted on roller bearings, which require regular, expensive maintenance. Other known solutions use a combined linear vibration generation and tamping movement via hydraulic cylinders.

[0006] Tamping work represents a costly disruption to operations, which is why the highest possible performance of tamping machines is crucial. Especially in line tamping, operating speed is of paramount importance. Higher operating speeds or line performance also require shorter cycle times, which can generally only be achieved by moving the satellite more quickly from one tamping area to the next, resulting in greater energy requirements for acceleration and deceleration of the tamping satellite. In previously known solutions, the satellite frame rests on a chassis connected to block or disc brakes and a drive acting on the wheels. The disadvantage of such conventional friction brakes is that a large portion of the kinetic energy is lost unused to the environment in the form of heat.

[0007] Another disadvantage of the state-of-the-art design is that the brakes, as well as the drive, depend on the coefficient of friction between the wheel and rail and the mass resting on the chassis. If the drive or braking force is too high, the drive wheels either skid or lock. Skidding or locking puts strain on the rail, and valuable time is lost. EP 1387003B1 discloses that the satellite's drive system can be assisted by an acceleration cylinder. Nevertheless, the deceleration of the tamping satellite is limited by the braking forces that can be transmitted via the satellite-side wheel-rail friction connection. For discontinuously operating tamping machines, it is known to use the tamping machine's electric drive system for braking and to utilize the electrical energy recovered during braking to apply vibrations to the tamping tools (WO 2019 / 068400 A1). Description of the invention

[0008] The invention is therefore based on the object of avoiding the disadvantages mentioned and enabling an increase in energy efficiency.

[0009] The invention solves the problem by assigning a hydraulic recuperation brake to the satellite that counteracts the drive.

[0010] Through recuperation, the kinetic energy generated during braking of the satellite is converted into hydraulic energy and preferably stored using hydraulic accumulators. This stored potential energy can subsequently be reused, either by feeding the energy into a hydraulic network, using it to retract the cylinder, or for the drive system, or similarly. In particular, the recuperation brake can hydraulically brake the satellite accelerated by the drive system.

[0011] For this purpose, the regenerative brake can brake the satellite via at least one brake cylinder, which engages the satellite at one end and the machine frame at the other. Particularly simple design conditions and a compact construction are achieved if the traction drive and the regenerative brake comprise at least one common double-acting cylinder, the first cylinder chamber of which is assigned to the traction drive and the second cylinder chamber to the regenerative brake.

[0012] In order to adjust the course of a braking ramp of the satellite, at least one control valve can be provided which controls or regulates a hydraulic fluid outflow from the cylinder chamber assigned to the recuperation brake.

[0013] At least one hydraulic accumulator is preferably provided to store energy recuperated by the recuperation brake.

[0014] The regenerative brake can be connected to a hydraulic on-board power system, in particular the traction drive, via a valve to support the hydraulic drive for a subsequent acceleration process. Additionally or alternatively, the regenerative brake can be connected to a hydraulic on-board power system via a valve to support the hydraulic drive of the tamping units and / or lifting-straightening units.

[0015] In particular, at least one hydraulically operated brake cylinder is provided between the satellite and the machine frame. The brake cylinder is directly connected to the machine frame and satellite, or, if located between the front end of the satellite and the machine frame, is rigidly connected exclusively to one of the two frames. In the latter design, the stroke of the brake cylinder is smaller than the maximum displacement of the satellite; the return of the brake cylinder to its original position (during the tamping process) occurs hydraulically, preferably using the previously stored braking energy. This energy should be stored very quickly and then be available for other hydraulic movement functions within the cycle time.The invention also enables high working speeds to be achieved with short braking times and the associated high required braking forces, which enable effective and precise deceleration of the satellite's forward movement.

[0016] To store energy in hydraulic accumulators, gases are used that are separated from the hydraulic fluid by a separating element (diaphragm, bladder, or piston). The energy can be stored and released again in a very short time. The course of the braking ramp, and thus the charging process of the hydraulic accumulator, can be specified via proportional control valves or servo valves in conjunction with appropriate control electronics. In the design according to the invention, the counterpressure in the bladder accumulator, which is charged by the moving mass during braking, is used to decelerate the satellite.

[0017] This allows the tamping satellite's kinetic energy to be converted into potential energy, instead of conventional dissipation through friction linings. The advantage is that the tamping satellite's deceleration is not limited by the braking forces transmitted via the satellite's wheel-rail adhesion.

[0018] What is particularly advantageous is that the stored hydraulic power is available to the drive train for the next acceleration process and / or other hydraulic movement functions - for example, the positioning movement or lifting movement of the tamping unit, which run cyclically before the next satellite braking process.

[0019] The main advantages of the invention are increased energy efficiency, increased operating speed, and reduced drive power requirements. A further advantage is the ability to position the satellite more precisely relative to the plunge position of the tamping units over the sleepers thanks to the adjustable braking effect. Brief description of the invention

[0020] The drawing shows an example of the subject matter of the invention. Fig. 1 a schematic representation of a continuously operating tamping machine 1 with satellites 3 and brake cylinder 4 in side view, Fig. 2 a schematic representation of the inventive recuperation of kinetic energy during deceleration of the satellite. Ways to implement the invention

[0021] The stuffing machine 1 ( Fig. 1 ) for tamping sleepers of a track 2, comprises a machine frame 14 which is movable on two rail bogies 9 and extends in the longitudinal direction of the tamping machine, and a satellite 3 which is arranged between the rail bogies 9 and is movable on the track 2 via a bogie 10, which is connected to the machine frame 14 via a satellite longitudinal guide 18 and which has a tamping unit 5 which is height-adjustable with respect to the satellite 3 and a track lifting and straightening unit 7 between the bogie 10 and the satellite longitudinal guide 18.

[0022] The satellite 3 is directly connected to the machine frame 14 and satellite 3 via at least one brake cylinder 4 assigned to a recuperation brake B, wherein a travel drive F accelerates the satellite 3 within a provided displacement range A between the rail bogies 9 and the brake cylinder 4 decelerates the satellite 3 within the displacement range A.

[0023] Due to the local standstill of the satellite 3 during the tamping process, in which the tamping machine 1 moves continuously in the working direction AR, the piston rod of the brake cylinder 4, which is in the pressureless floating position, can gradually move back to the starting position.

[0024] In a further embodiment of the invention, not shown in detail, the brake cylinder 4 can also be rigidly connected exclusively to one of the two frames 14, 3, provided that it is arranged between the front end of the satellite 3 and the machine frame 14. In the latter embodiment, the stroke of the brake cylinder 4 is smaller than a maximum displacement path A of the satellite.

[0025] Within the machine frame 14 of the machine, the longitudinally displaceable satellite 3 rests on the chassis 10. The satellite 3 is guided longitudinally displaceably by satellite longitudinal guides 18 in the main frame 14 in the manner of a wheelbarrow, with one end equipped with a running gear and the other end equipped with guide arms. The machine 1 with the tamping cabin 15 is movable along the track 2 via bogies 9, 10. The machine has a track measuring system 6, 11, 12 which controls the lifting and leveling unit 7, which is integrated into the satellite 3. On the satellite 3 there is a lowerable and raiseable tamping unit 5, which can be rotated by an angle about the vertical axis via a slewing ring 19 and can also be displaced transversely via a displacement device 20 arranged transversely to the working direction. The lifting and straightening unit can be moved in the longitudinal direction of the track via a linear drive 8 which is connected to the satellite frame 13.At least one lifting cylinder H and at least one straightening cylinder R are assigned to the track lifting and straightening unit 7.

[0026] The system diagram according to Fig. 2shows the energy recovery and storage according to the invention. To decelerate the satellite 3, the counterpressure in the hydraulic accumulator 22 is used, which is charged when the moving mass of the satellite 3 is decelerated. The course of the braking ramp, and thus the charging process of the hydraulic accumulator 22, can be specified via a control valve 21. The hydraulic power stored in the hydraulic accumulator 22 is made available via the control or regulating valve 23, for example, to the satellite drive 16 for the next acceleration process and / or other hydraulic movement functions, such as the tamping unit 5 or the lifting-straightening unit 7. If necessary, the brake cylinder for pushing back the satellite 3 can also be acted upon by energy stored in the hydraulic accumulator 22 via the control valve 21.

Claims

1. Tamping machine (1) for tamping sleepers of a track (2), having a machine frame (14) which can be moved on rail undercarriages (9) and extends in the longitudinal direction of the tamping machine, and a satellite (3) which is arranged between the rail undercarriages (9) and can be moved between the rail undercarriages (9) via an undercarriage (10) and a travel drive (F) on the track (2), which satellite (3) is guide-connected to the machine frame (14) via a satellite longitudinal guide (18) and which has, between the running gear (10) and the satellite longitudinal guide (18), a tamping unit (5) which is vertically adjustable with respect to the satellite (3) and a track-lifting / straightening unit (7), characterized in that the satellite (3) is assigned a hydraulic recuperation brake (B) which counteracts the travel drive (F).

2. Tamping machine according to claim 1, characterized in that the recuperation brake hydraulically brakes the satellite (3) accelerated by the travel drive (F).

3. Tamping machine according to claim 2, characterized in that the recuperation brake brakes the satellite (3) via at least one brake cylinder (4) which engages at one end on the satellite (3) and at the other end on the machine frame (14).

4. Tamping machine according to claim 2 or 3, characterized in that at least one control valve (21) is provided for adjusting the course of a braking ramp of the satellite (3).

5. Tamping machine according to one of claims 2 to 4, characterized in that the recuperation brake comprises at least one hydraulic accumulator (22) for storing recuperated energy.

6. Tamping machine according to claim 5, characterized in that the recuperation brake is connected via a valve (23) to a hydraulic on-board network, in particular of the traction drive (F), for the purpose of supporting the hydraulic traction drive (F) for a subsequent acceleration process.

7. Tamping machine according to claim 5 or 6, characterized in that the recuperation brake is connected to an on-board hydraulic network via a valve (23) for the purpose of supporting the hydraulic drive of the tamping units (5) and / or lifting / straightening units (7).

8. Tamping machine according to one of claims 2 to 7, characterized in that the travel drive (F) and the recuperation brake (B) comprise at least one common double-acting cylinder, the first cylinder chamber of which is assigned to the travel drive (F) and the second cylinder chamber of which is assigned to the recuperation brake (B).

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