EP3728736A1

EP3728736A1 - Method for operating a tamping assembly of a track construction machine, and tamping device for track bed compaction, and track construction machine

Info

Publication number: EP3728736A1
Application number: EP18811471.4A
Authority: EP
Inventors: Thomas Philipp
Original assignee: Plasser und Theurer Export Von Bahnbaumaschinen GmbH
Current assignee: Plasser und Theurer Export Von Bahnbaumaschinen GmbH
Priority date: 2017-12-21
Filing date: 2018-11-20
Publication date: 2020-10-28
Also published as: US11834794B2; WO2019120829A1; JP2021507151A; AT520791A1; AT520791B1; EA202000146A1; JP7206278B2; US20200392672A1; CN111479965B; CN111479965A

Abstract

In a method for operating a tamping assembly (8) of a track construction machine (1), a track construction machine (1) having a tamping assembly (8), a drive force sensor system and an acceleration sensor system is first provided on a track bed (21). The tamping assembly (8) is displaced relative to the track bed (21). A drive force (F_A), which acts on the tamping assembly (8) and is necessary for the displacement, and an acceleration (a_z) acting on the tamping assembly (8) are determined. A ballast force (F_s) effective between the tamping assembly (8) and the track bed (21) is defined using the drive force (F_A) and the acceleration (a_z) and is evaluated.

Description

Method for operating a tamping unit of a track construction machine and

Stopfvorrichtung for track bed compaction and track construction machine

Field of engineering

[01] The invention relates to a method for operating a tamping unit of a track construction machine and also to a stuffing device for track bed compaction and to a track construction machine.

State of the art

[02] Track-guided track-laying machines are used to maintain a

Trackbed used. Such track construction machines have to

Track bed compaction a stuffing device with a relocatable

Tamping unit on. The tamping unit is repeated in operation between a reset position in which the tamping unit is out of engagement with the track bed and an engagement position in which the tamping unit is in engagement with the track bed, relocated. High static and dynamic loads act on the tamping unit. To maintain the functionality of highly stressed parts of the tamping unit time-consuming and costly inspection and maintenance are performed regularly.

Summary of the invention

The invention has for its object to provide a method for operating a Stopfaggregats a track construction machine, which increases the performance and efficiency of Stopfaggregats.

[04] This object is achieved by a method having the features of claim 1. According to the invention, it has been recognized that the between the

Stopfaggregat and the track bed, in particular along a

Displacement direction of the tamping, acting ballast force for the stress of the tamping unit is essential and that this can be determined exactly on the basis of the driving force and the acceleration. By the determination and evaluation of the ballast force, the tamping unit can be operated efficiently and economically. For example, heavily used parts can be identified and designed and maintained in accordance with the requirements. The processing of the track bed can also under

Ensuring a high ratio between one

Processing speed and energy consumption and under

Consideration of the gravel forces essential for wear are such that the expected downtimes are reduced by maintenance. By determining and evaluating the ballast force thus the performance and the economy of the track construction machine can be increased.

[05] The displacement of the tamping unit relative to the track bed is at least, in particular exclusively, in the vertical direction. Relocating the

Stopfaggregats preferably takes place between the return position and the engaged position. In the return position, the tamping unit is raised and is out of engagement with the track bed. In particular, that can

Stopfaggregat in the return position in the vertical direction so

be arranged so that it is completely positioned above railway sleepers and / or tracks. Preferably, the tamping unit has at least two, in particular at least four tamping picks. In the engaged position, the tamping unit, in particular the at least two tamping picks, dips into the track bed. In a between the reset position and the

Engagement position arranged delivery position, the tamping unit comes into contact with the track bed. The track bed compaction can be carried out during the shifting from the delivery position to the engagement position.

[06] To determine the ballast force, the driving force acting on the tamping unit and required for displacement is determined. Under the

Driving force is understood to mean that force which is used to displace the stuffing unit between the return position and the engaged position,

especially in the vertical direction, is required. The driving force can be detected, for example, by means of a force sensor. The driving force may be on the tamping unit and / or on the unit carrier and / or on a acting between the tamping unit and the unit carrier

Drive device to be detected.

[07] To determine the acceleration acting on the tamping unit, an acceleration sensor can be used. The acceleration can be detected at the tamping unit and / or at the drive device.

[08] The ballast force is determined by the driving force and the acceleration

certainly. Under the ballast force that force is understood that between the track bed and the Stopfaggregat, in particular the

at least two stuffing tacks, acts and along the displacement between the return position and the engagement position, in particular in the vertical direction, is oriented. By taking into account both the driving force and the acceleration of the tamping unit, the ballast force can be reliably and accurately determined despite the harsh operating conditions.

[09] A method according to claim 2 ensures the increased performance and economy of the track construction machine. The position of the Stopfaggregats, especially in the vertical direction, can be detected very reliable and robust. Used to move the tamping unit

Position sensors can be used, eliminating the need to integrate additional sensors. The detection of the acceleration is thus particularly economical. The position can be detected on the drive device. The position can also be detected on a bearing device, by means of which the tamping unit is mounted relative to the unit carrier.

The position can be determined by means of a position sensor, in particular a

Position encoder or a rotary encoder, in the form of a potentiometer or a Hall sensor or a rope length sensor are detected. To record the change over time of the position, the time profile of the position can be differentiated by means of an evaluation unit according to time, or the change in position can be determined over a discrete time step. From the temporal change of the position, ie the speed, the acceleration is determined as a temporal change of the speed. Preferably, the position and thus the acceleration are detected relative to the unit carrier. Taking into account the gravitational acceleration, the absolute

Acceleration of Stopfaggregats be determined. [10] A method according to claim 3 ensures the increased performance and economy of the track construction machine. Taking into account the inertial force dependent on the mass, the ballast force can be determined particularly accurately. The mass of the tamping unit can be weighed prior to installation in the track-laying machine or on the track-laying machine. Alternatively, the mass of the Stopfaggregats can be determined in the reset position by detecting the driving force. In the unaccelerated state, the weight and thus the mass of the Stopfaggregats can be determined by the driving force.

[11] A method according to claim 4 ensures the increased performance and economy of the track construction machine. The fluidically actuated

Drive device is robust in operation and ensures the provision of necessary for the processing of the track bed power. Determining the driving force by detecting at least one fluid pressure acting on the drive device can be particularly robust. By using necessary for the pressure control pressure sensors can

Stopfaggregat be made particularly economical by avoiding redundancies. The drive device preferably has at least one hydraulic cylinder and / or at least one pneumatic cylinder.

A guided within the respective cylinder piston is with a

Piston rod connected and has a piston rod facing the piston ring surface and one of the piston ring surface opposite

Piston surface. Preferably, the detection of the fluid pressure is effected by detecting a piston pressure acting on the piston surface and / or a piston ring pressure acting on the piston ring surface.

A method according to claim 5 ensures the increased performance and economy of the track construction machine. When operating the

Track construction machine, the tamping unit, in particular the at least two tamping picks, the drive device and the bearing device, heavily stressed mechanically. The ballast force is essential for the stress of the tamping unit. By evaluating the stress on the basis of the ballast force, the track construction machine can be designed to be robust and operated efficiently and economically. [13] A method according to claim 6 ensures the increased performance and economy of the track construction machine. When relocating the

Stopfaggregats between the return position and the engaged position varies greatly acting on the tamping ballast power. By determining the stress based on the time course of

Gravel force, changes in the ballast force can be considered. Preferably, the stress of the tamping aggregate is determined via at least one tamping cycle. A stuffing cycle involves displacing the stuffing assembly from the return position to the engaged position and back from the engaged position to the return position. The load on the tamping unit can also be maintained over the entire service life of the tamping unit

Stopfaggregats be determined. Preferably, the stress on the tamping unit, in particular the at least two tamping picks, is determined at least over the duration of a tamping cycle, in particular over a plurality of tamping cycles, and in particular over the entire service life. In addition to the static load, the temporal course of the ballast force also provides conclusions about the dynamic load of the tamping unit. With knowledge of the dynamic load, maintenance cycles can be optimized and maintenance costs reduced.

[14] A method according to claim 7 ensures the increased performance and economy of the track construction machine. Depending on the trackbed to be worked, the ballast force varies within and between different stuffing cycles. It was recognized that for the stress of the tamping aggregate the ballast force amplitudes, that is the amplitudes of the changing ballast force, are of essential importance. For determining the ballast force amplitudes, the time course of the ballast force between a first and a second measuring point can be detected, wherein the ballast force to the first and to the second measuring point is the same size and wherein the second measuring point is determined by the first-time re-reaching this ballast force. The ballast force amplitude is called

Difference between the maximum ballast force value and the minimum ballast force value between the first and the second measuring point determined. [15] A method according to claim 8 ensures the increased performance and economy of the track construction machine. To determine the

Load collective is the cumulative frequency of the ballast force amplitudes determined. Preferably, the bandwidth of the occurring ballast force amplitudes is first divided into ballast force amplitude sections. To determine the load spectrum, the frequency of the occurring and in the respective ballast force amplitude section falling ballast force amplitude can be counted. The load collective thus provides information about the height and frequency of the alternating stress acting on the tamping unit. The load collective is therefore particularly suitable for evaluating the dynamic stress acting on the tamping unit.

[16] A method according to claim 9 ensures the increased performance and economy of the track construction machine. When the at least two tamping knives penetrate into the track bed, the ballast work is transferred between the tamping unit and the track bed. The ballast work correlates with the stress of the tamping unit. By means of ballast work, the stress of the tamping aggregate can be determined particularly efficiently. To determine the ballast work, the ballast force and the position can each be determined after certain time steps. Subsequently, the change in position over this time step can be multiplied by the ballast force, in particular the mean ballast force over this time step. Alternatively, the ballast force can also be integrated via the position.

[17] A method according to claim 10 ensures the increased

Performance and efficiency of the track-laying machine. To the

Determining the state of wear, the stress acting on the tamping unit can be compared with a maximum permissible load. On the basis of the state of wear, a prognosis can be made as to how long the tamping unit can still be operated before a failure occurs, in particular before individual parts of the tamping unit fail. The state of wear may also indicate the need for maintenance work, in particular replacement of the

Tamping unit to be closed. With knowledge of the wear condition can the track construction machine, in particular the tamping, under

Operating life longer, reducing downtime and reducing maintenance costs.

[18] A method according to claim 11 ensures the increased performance and economy of the track construction machine. The setting of at least one process parameter for controlling the Stopfaggregats based on

Stress ensures an influence on the stress of the tamping unit. Possible process parameters are, for example, a frequency and / or an amplitude of the vibration and / or displacement component transmitted to the at least one tamping pick, an adjustment speed of the tamping unit between the return position and the engagement position, the acceleration of the tamping aggregate and the fluid pressure acting on the drive device , Advantageously, it is thereby achieved that the at least one process parameter can be adjusted as a function of the track bed to be processed and the stress resulting from the nature of the respective track bed. Depending on the trackbed, thus the energy consumption and the

Processing speed considering the on the

Stopfaggregat acting stress can be optimized.

[19] A method according to claim 12 ensures the increased performance and economy of the track construction machine. By changing at least one process parameter when a threshold value of the stress is exceeded, both an overuse of the tamping aggregate and a too low processing speed of the track bed can be counteracted. Preferably, the at least one

If an upper threshold value is exceeded, the process parameters are reduced so that the load on the tamping unit decreases. at

Falling below a lower threshold, the at least one process parameter can be changed so that the stress increases. It is advantageously achieved by a difference between the upper and the lower threshold that the at least one

Process parameters are not subject to constant change. [20] A method according to claim Ί3 ensures the increased performance and economy of the track construction machine. By setting the at least one process parameter to the effect that a load limit value is not exceeded, a failure of the tamping unit, in particular the at least two tamping picks, can be reliably prevented. The stress limit value may be a static and / or dynamic, in particular experimentally determined, strength value of the tamping aggregate, in particular of individual parts of the tamping aggregate. The at least one process parameter can be continuously changed based on the stress, or the change can be made in discrete steps. For example, an oscillation frequency of the at least two stuffing picks can be changed continuously between 30 Hz and 50 Hz. Alternatively, the

Oscillating frequency in a first mode 35 Hz and in a second mode 45 Hz. The tamping unit can be operated in the first and in the second mode, which can be switched on the basis of the load between the first mode and the second mode. The

Stopfaggregat can be operated in more than two modes of operation. Each mode of operation differs from another mode of operation in at least one process parameter.

[21] On the basis of ballast and / or stress

different types of tamping units are compared and evaluated. The ballast force and / or the stress can also be used to optimize the tamping unit, in particular the kinematics and / or the storage and / or the materials used and / or the structural design.

The invention is also based on the object to provide a stuffing device for track bed compaction, which has an increased efficiency and cost-effectiveness.

This object is achieved by a stuffing device with the features of

Claim 14 solved. The advantages of the stuffing device according to the invention correspond to the advantages of the method according to the invention. The

Stopfvorrichtung can be further developed in particular with the features of at least one of claims 1 to 13. Preferably, the tamping unit slidably mounted on the unit carrier in the vertical direction. The drive device may comprise a hydraulic cylinder. For engagement in the track bed, the tamping unit preferably comprises at least two, in particular at least four tamping picks. The driving force sensor system can have at least one pressure sensor and / or at least one force sensor. The acceleration sensor system can have at least one

Speed sensor and / or at least one position sensor and / or at least one acceleration sensor. The

Position sensor can be designed as a contactless sensor. The position sensor can be arranged between the tamping unit and the unit carrier, in particular on the drive device. Preferably, the at least one position sensor is designed as a potentiometer and / or as a Hall sensor and / or as a rope length sensor.

The invention is further based on the object to provide a track construction machine with a stuffing device, which has an increased efficiency and cost-effectiveness.

[25] This object is achieved by a track construction machine with the features of claim Ί5. The advantages of the track construction machine according to the invention correspond to the advantages of the stuffing device according to the invention. The track construction machine can be developed in particular with the features of at least one of claims Ί to Ί4.

Brief description of the drawings

[26] Further features, advantages and details of the invention will become apparent from the following description of an embodiment. Show it:

Fig. Ί is a schematic representation of a rail-guided

Track construction machine with a stuffing device for

Roadbed compaction,

Fig. 2 is a schematic front view of the stuffing device in Fig. Ί, wherein the stuffing device a tamping unit with four

Having stuffing tacks and wherein the stuffing tacks are in engagement with a track bed, Fig. 3 is a schematic side view of the stuffing device in Fig. 1, wherein a driving force, an inertial force and a

Ballast force acting on the tamping aggregate,

Fig. 4 gradients of the driving force, the inertial force and the

Gravel force over time and for a single tamping cycle, Fig. 5 Course of the ballast force over time for six tamping cycles,

Fig. 6 course of detected load amplitudes of the ballast force over a

Load game number and

Fig. 7 shows a course of a position of the tamping unit, the ballast power and a ballast work over time.

Description of the embodiments

[27] A track construction machine Ί has a machine frame 2, at least two axles 3 mounted on the machine frame 2, a machine drive 4 and a stuffing device 5 for track bed compaction. The axles 3 are spaced apart from each other along a horizontal x-direction

Track-laying machine Ί arranged. The x-direction, together with a vertical z-direction and a horizontal y-direction, forms a machine-fixed coordinate system. On the axles 3 rail-guided wheels 6 are rotatably mounted. The machine drive 2 is designed for rotational driving of the wheels 6 of at least one of the axles 3.

[28] The stuffing device 5 has an assembly carrier 7 and a tamping unit 8 mounted in the z-direction relative thereto. The tamping unit 8 comprises four tamping picks 8a and a compacting drive 8b. The tamping picks 8a are each mounted on a stuffing tine carrier 8c and are rotatably mounted on the latter about a carrier axis 8d. By means of the compression drive 8b, the stuffing tine carriers 8c can be driven in rotation about the respective carrier axis 8d.

The stuffing device 5 is on the unit carrier 7 on the

Machine frame 2 attached. The tamping unit 8 is displaceable relative to the unit carrier 7. For this purpose, a linear bearing Ί0 is formed between the unit carrier 7 and the tamping unit 8. The linear bearing Ί0 has on the unit carrier 7 mounted bearing rails ΊΊ and with the

Stopfaggregat 8 connected bearing sleeves Ί2 on. [30] The stuffing device further comprises a drive device 9. The

Drive device 9 comprises a hydraulic cylinder Ί3. The

Hydraulic cylinder Ί3 acts between the unit carrier 7 and the

Stopfaggregat 8. In the hydraulic cylinder Ί3 a hydraulic piston Ί4 is mounted linearly displaceable with a piston rod attached thereto Ί5. The hydraulic piston Ί4 has a piston ring surface AKR facing the piston rod Ί5 and a piston rod Ί5 facing away from the piston rod

Piston surface AK on. A piston pressure rk of a hydraulic fluid in the hydraulic cylinder Ί3 acts on the piston surface AK. A piston ring pressure PKR of the hydraulic fluid acts on the piston ring surface AKR. From the piston pressure rk acting on the piston surface AK and the piston ring pressure PKR acting on the piston ring surface AKR, a total driving force FA transmitted via the piston rod Ί5 to the tamping unit 8 results.

[31] The stuffing device 1 has a drive force sensor system for detecting a first measured variable rk, PKR, F _A corresponding to the drive force F _A. The driving force sensor includes a piston pressure sensor 16 for detecting the piston pressure rk and a piston ring pressure sensor 17 for detecting the piston ring pressure PKR. FROM acting on the piston surface AK

Piston pressure rk and from acting on the piston ring surface AKR

Piston ring pressure PKR can be closed to the total acting on the tamping unit 8 via the piston rod 15 driving force F _A. The

Driving force F _{A is} calculated as follows:

F _A ^- PKR ^' ΆKR ^- Rk ^' Άk P)

[32] The stuffing device 1 has an acceleration sensor system for detecting a second measured variable corresponding to an acceleration a _{z of} the stuffing unit 8, the position z and / or the speed v _z . The acceleration sensor system is designed in the form of a displacement transducer 18.

The displacement sensor 18 is on the unit carrier 7 and on the

Stopfaggregat 8 attached. The displacement transducer 18 is designed to detect the position z and the speed v _{z of} the tamping unit 8 relative to the unit carrier 7 in the z-direction. [33] To determine the ballast force Fs acting on the tamping unit 8, the tamping device 5 comprises an evaluation unit Ί9. The evaluation unit Ί9 is in signal communication with the piston pressure sensor 16, the

Piston ring pressure sensor 17 and the displacement sensor 18. In addition, the evaluation unit 19 is in signal communication with a pressure regulator 20. The pressure regulator 20 is for controlling the piston pressure rk and the

Piston ring pressure PKR trained on one setpoint each. The respective setpoint for the piston pressure rk and the piston ring pressure PKR is of the

Evaluation unit 19 can be specified.

[34] The following describes the operation of the track-laying machine 1 and the operation of the tamping unit 8:

[35] To create and / or maintain a trackbed 21, the

Track construction machine 1 by means of the machine drive 4 on a track 22 along the x-direction procedure. A central axis 23 of the stuffing device 5 is thereby positioned centrally above a railway sleeper 24 arranged on the track bed 21 and supporting the tracks 22.

At the beginning of the process for track bed compaction is the

Stopfaggregat 8 in a reset position 25. The bearing sleeve 12 is located at an upper end of the linear bearing 10 and the piston rod 15 largely immersed in the hydraulic piston 14 a. The tamping picks 8a attached to the tamping unit 8 are disengaged from the track bed 21. The piston surface AK is at the piston pressure rk, and the piston ring surface AKR is acted upon at the piston ring pressure PKR. By means of the evaluation unit 19, the force acting on the tamping unit 8 by the hydraulic piston 14 driving force FA is determined. For this purpose, the piston pressure rk is multiplied by the piston area AK and the piston ring pressure PKR by the piston ring area AKR. For the driving force FA thus applies:

[37] In the return position 25, the tamping unit 8 rests relative to the

Aggregate support 7 and the tamping unit 8 acts only the

Gravitational acceleration g. For the acceleration a _{z of} the tamping unit 8 relative to the unit carrier 7, a _z = 0 and for the ballast force F _s , F _s = 0. For the equilibrium of forces along the z direction on the tamping unit 8, the following applies:

[38] By means of the evaluation unit Ί9, the mass m of the tamping unit is determined in the reset position 25 before starting the operation of the stuffing device 5. Taking into account the in the reset position 25th

prevailing boundary conditions apply to the mass m:

The mass m of Stopfaggregats 8 is in a memory element of

Evaluation unit Ί9 stored.

[40] The compaction of the track bed 2Ί is divided into individual stuffing cycles. Along the z-direction, the tamping unit 8 is displaced during the stuffing cycle from the return position 25 into a delivery position 26 and an engagement position 27. In the delivery position 26, the tamping picks 8a contact the

Trackbed 21, but do not penetrate into this. In the engagement position 27, the tamping picks 8a penetrate into the track bed 21. The Stopfzyklus is completed when the tamping unit 8 is shifted back from the engagement position 27 via the feed position 26 back to the reset position 25. The ballast force Fs is by means of the evaluation unit 19 from the inertial force F and the

Driving force FA determined. To determine the inertial force F, the speed v _{z of} the tamping unit 8 relative to the unit carrier 7 in the z direction is first determined as a change in the position z over time t. The acceleration a _z is again determined as a change in the speed v _z over the time t. The acceleration a _z is thus calculated as follows:

[41] At the beginning of the stuffing cycle, the evaluation of the time t begins

dependent ballast force Fs (t). Based on the driving force F _A (t) and the

Acceleration a _z (t) and with knowledge of the mass m and the

Gravitational acceleration g, the ballast force Fs (t) is determined as follows:

^F s (t) = - ^F T (t) ^F A (t) = ^m k (t) + g] ^{~ F} A (t) (6)

[42] To displace the tamping unit 8 from the reset position 25 counter to the z-direction into the infeed position 26, the drive device is first of all 9 pressed. The piston pressure rk is increased and the piston ring pressure PKR is lowered. The driving force FA acting on the tamping unit 8 via the piston rod Ί5 is increased counter to the z-direction. From the driving force F _A results on the tamping unit 8 acting acceleration a _z , which is oriented counter to the z-direction and to a rising

Speed v _z of Stopfaggregats 8 leads in the direction of the track bed 2Ί. The tamping unit 8 is displaced counter to the z-direction. Contrary to the driving force FA, the amount of inertia force F, which has the same magnitude, acts. The

Ballast force Fs is equal to zero before the tamping pick 8a contacts the track bed 2Ί.

In the delivery position 26 reach the tamping picks 8a in engagement with the

Track bed 2Ί. Between the infeed position 26 and the engagement position 27, the partial ballast forces Fsi, FS2, FS3 and F _s 4 additionally act in the z direction on the tamping unit 8 via the four tamping picks 8a

Gravel forces F _Si , F _S 2, F _S 3 and F _S4 add up to the ballast force F _s. About the displacement between the feed position and the engagement position 27, the ballast force Fs is not equal to zero.

The courses of the driving force FA, the inertial force F and the ballast force Fs are shown in detail in FIG. 4 over the time t for the duration of a stuffing cycle. The displacement of the Stopfaggregats 8 between the

Reset position 25 and the engagement position 27 takes place in the delivery phase 28. Time-spaced to the delivery phase 28, the reset phase 29 connects.

[45] In the return phase 29, the tamping unit 8 is moved back from the engagement position 27 via the feed position 26 in the return position 25. For this purpose, the drive device 9 is actuated in such a way that the piston pressure rk is reduced and the piston ring pressure PKR is increased. The hydraulic cylinder Ί3 thus causes the driving force FA, which is now oriented in the z-direction. The tamping unit 8 is due to the driving force FA in the z direction

accelerated. The acceleration a _z is oriented in the z direction and results in a speed v _z increasing in the z direction and the displacement of the tamping unit 8 in the z direction. Between the engagement position 27 and the delivery position 26, the ballast force Fs acts on the Stopfaggregat 8. Between the delivery position 26 and the return position 25 act only the

Driving force F _A and the magnitude of the same size and oppositely oriented inertial force F _T on the tamping unit 8, wherein the ballast force Fs is equal to zero.

[46] During the stuffing cycle, the tamping picks 8a are vibrated by operation of the compression drive 8b. This drives the

Compression drive 8b the tamping pickup carrier 8c substantially in the horizontal direction, whereby the stuffing tine carrier 8c and the tamping pickles 8a attached thereto rotate about the respective carrier axis 8d. The movement of the tamping picks 8a about the respective carrier axis 8d essentially comprises two components of movement. A vibration component causes only a small rotational amplitude of the tamping picks 8a about the respective carrier axis 8d, wherein an oscillation frequency fs is between 35 Hz and 45 Hz. The vibration component acts on the tamping picks 8a during the entire tamping cycle. In addition to the

Vibration component, the tamping 8a with a

Displacement component applied. The displacement component has a higher rotational amplitude than the vibration component and a

Displacement frequency of about 0.5 Hz. In the engagement position 27, the tamping picks 8a are thereby rotated about the respective carrier axis 8d such that the stuffing tacks 8a, which are spaced apart from one another in the x-direction, move towards one another. In the reset position 25, the displacement component is oriented in such a way that the tamping picks 8a move away from each other again. The loading of the tamping picks 8a with the displacement component follows in the displacement phase 30. By the superimposed loading of the tamping picks 8a with the vibration component and the

Displacement component is the compression of the track bed 2Ί.

[47] The stuffing cycle is finished as soon as the tamping unit 8 is in the reset position 25 again. For further compression of the track bed 2Ί, the track-laying machine Ί is displaced in the x-direction until the central axis 23 is arranged centrally above the next in the x-direction railway sleepers 24. In this the stuffing cycle is repeated. The course of the ballast force Fs over the time t is shown in FIG. 5 for six consecutive stuffing cycles. [48] By means of the evaluation unit Ί9 the stress of the stuffing device 5 is determined on the basis of the time course of the ballast force Fs. The

Stress is determined by means of ballast force amplitudes S _Fs of

Ballast force Fs determined. The ballast force Fs is a temporally variable, oscillating load. The ballast force amplitude S _Fs is determined as the difference of a maximum ballast force Fs and a minimum ballast force Fs within a vibration. In addition to the ballast force amplitudes S _Fs , the cumulative frequency N _{Fs of} the respective ballast force amplitude S _{Fs is} determined. To determine the stress, a load collective is determined on the basis of the cumulative frequency N _Fs .

[49] In Fig. 6 is a curve of the ballast force amplitude S _Fs above the

Sum frequency N _Fs shown. By adjusting the course of the

Ballast force amplitude S _Fs over the cumulative frequency N _Fs with a maximum allowable cumulative frequency N _Fs of ballast force amplitude S _Fs , a state of wear of Stopfaggregats 8 is determined. The state of wear is determined both for individual parts of the tamping unit 8, such as the tamping picks 8a, the drive device 9 and the linear bearings 10, as well as for the entire tamping unit 8.

[50] Depending on the stress will be at least one

Process parameters p _K , PKR, fs set to operate the Stopfaggregats 8 by means of the evaluation unit 19. For this purpose, the evaluation unit 19 is in signal communication with the compression drive 8b for controlling the oscillation frequency fs and with the pressure regulator 20 for controlling the piston pressure rk and the piston ring pressure PKR. When a threshold value SW of the load is exceeded, the at least one process parameter p _K , PKR, fs is changed. By means of the evaluation unit 19, the ballast force F _{s is} compared with the threshold SW for this purpose, wherein the at least one

Process parameter p _K , PKR, fs is changed when exceeding an upper threshold SWi such that the ballast force Fs is reduced, wherein when falling below a lower threshold SW2 the at least one process parameter p _K , PKR, fs is changed such that the ballast force F _s is increased. The ballast force Fs is increased by increasing the oscillation frequency fs and by reducing the pressure difference between the Piston pressure rk and the piston ring pressure PKR reduced and increased in the opposite manner. The process parameters p _K PKR, fs are changed by means of the evaluation unit Ί9 to the effect that an optimum between a low stress of the stuffing 5 and a high processing speed of the track bed 2Ί takes place.

[51] Alternatively, to determine the stress, it may be possible to determine the stress

Load collective also a ballast Ws be determined by means of the evaluation unit 19. The ballast work Ws is determined from the ballast force Fs and a change in the position z of the tamping unit 8. The

Ballast work W _s corresponds to the work brought into the track bed 21 via the tamping picks 8a. The change in the position z is recorded over a discrete time period. This change in position z is then multiplied by the ballast force Fs. The ballast work Ws is determined as the sum of the products of the ballast force Fs and the changes of the positions z.

[52] In Fig. 7, the curves of the position z, the ballast force F _s and the

Ballast work Ws for a stuffing cycle over the time t applied. The gravel work Ws can also be considered the area under the course of

Ballast force Fs above the position z are understood.

By determining the ballast force Fs acting on the tamping unit 8 by means of the evaluation unit 19 conclusions can be drawn on the stress of the tamping unit 8. The determination of the ballast force Fs taking into account the driving force FA and additionally the acceleration a _z is much more accurate compared to an exclusive consideration of the driving force FA for determining the ballast force Fs. The stress on the Stopfaggregats 8 can thus be reliably determined and a state of wear of the Stopfaggregats 8 can be determined reliably. The adaptation of the at least one process parameter rk, PKR, fs in

Dependence on the load enables the efficient and economical operation of the track-laying machine. In this case, in particular by means of an optimization, a high processing speed, low energy consumption and reduced stress on the

Stopfaggregats 8 reached.

Claims

claims

Ί. A method of operating a tamping aggregate of a track construction machine comprising the steps of:

Providing a track construction machine (Ί) with a tamping unit (8) on a track bed (21),

Displacing the tamping unit (8) relative to the track bed (21),

- Determining a on the tamping unit (8) acting and for relocating

required driving force (FA),

Determining an acceleration acting on the tamping unit (8) (a _z ),

Determining one between the tamping unit (8) and the track bed (21)

acting ballast force (Fs) on the basis of the driving force (FA) and the acceleration (a _z ) and

- Evaluation of the ballast force (F _s ).

2. The method of claim 1, dadu rch geken nzeichnet that the

Acceleration (a _z ) by detecting a change in time of a position (z) of Stopfaggregats (8) is determined.

3. The method according to claim 1 or 2, dadu rch geken nzeichnet that for determining the ballast force (Fs) acting on the tamping unit (8)

Inertia force (F) is determined by the acceleration (a _z ).

4. The method according to any one of claims 1 to 3, dadu rch in that the displacement of the Stopfaggregats (8) by means of a fluidically actuated

Drive device (9) takes place, wherein for determining the driving force (FA) at least one on the drive means (9) acting fluid pressure (rk, PKR) is detected.

5. The method according to any one of claims 1 to 4, dadu rch in that the evaluation is carried out such that one on the tamping unit (8) acting

Stress is determined on the basis of the ballast force (Fs).

6. Method according to claim 5, characterized in that the stress is determined on the basis of a time course of the ballast force (Fs).

7. The method according to claim 5 or 6, dadu rch geken nzeichnet that the stress on the basis of ballast force amplitudes ) of the ballast force (Fs) is determined.

8. Method according to claim 7, characterized in that a load collective is determined on the basis of a cumulative frequency (N _F ) of the ballast force amplitudes (S _F ) in order to determine the load.

9. The method according to any one of claims 5 to 8, dadu rch in that for determining the stress of a ballast work (Ws) from the ballast force (Fs) and a change in a position (z) of the tamping unit (8) is determined.

10. The method according to any one of claims 5 to 9, dadu rch characterized in that based on the stress, a state of wear of the Stopfaggregats (8) is determined.

11. The method according to any one of claims 5 to 10, dadu rch characterized in that at least one process parameter (f _s , v _z , a _z , rk, PKR) for controlling the

Stopfaggregats (8) is adjusted depending on the stress.

12. The method of claim 11, dadu rch geken nzeichnet that the at least one process parameter (f _s, v _z, a _z, rk, PKR) is changed when exceeding or falling below a threshold value of the stress.

13. The method according to claim 11 or 12, characterized in that the at least one process parameter (f _s , v _z , a _z , rk, PKR) is set such that the stress does not exceed a stress threshold.

14. Stopfvorrichtung for track bed compaction, comprising

an aggregate carrier (7), - A tamping unit (8) mounted on the unit carrier (7)

- A drive device (9) for providing a driving force (FA) and the

Displacing the tamping unit (8) relative to the unit carrier (7),

a driving force sensor for detecting a driving force (FA)

corresponding first measured variable (rk, PKR, FA),

- An acceleration sensor for detecting a to an acceleration (a _z ) of the Stopfaggregats (8) corresponding second measured variable (z, v _z , a _z ) and

an evaluation unit (Ί9) for determining a tamping unit (8)

acting ballast force (F _s ) based on the first measured variable (rk, PKR, FA) and the second measured variable (z, v _z , a _z ).

Ί5. Track construction machine, comprising

a machine frame (2),

at least two axles (3) mounted on the machine frame (2) with rail-guided wheels (6) arranged thereon,

- A machine drive (4) for rotationally driving the wheels (6) at least one of the axles (3) and

- At least one on the machine frame (2) fixed stuffing device (5) according to claim Ί4.