EP3649289B1 - Method and device for compacting a track ballast bed - Google Patents

Description

Field of technology

The invention relates to a method for compacting a track ballast bed by means of a tamping unit, which comprises two opposite tamping tools, which are subjected to vibration during a tamping process and are lowered into the track ballast bed and moved towards one another with a set-up movement. The invention also relates to a device for carrying out the method.

State of the art

Tamping units for tamping under sleepers are already known several times, such. B. by AT 500 972 B1 or AT 513 973 B1 . Vibrations acting on the tamping tools can either be generated mechanically by an eccentric shaft or by hydraulic impulses in a linear motor. Various setting options can be made by an operator. From the DE 31 44 485 A1 a tamping unit is known in which an amplitude limitation of a lateral displacement of a tamping unit can be specified. An adjustment of the vibration of the tamping tools is from the AT 339 358 B famous. This enables the vibration frequency, amplitude and vibration forces to be adapted to the respective ballast conditions.

AT 515 801 B1 describes a method for compacting a track ballast bed by means of a tamping unit, whereby a quality number for a ballast bed hardness is to be shown. For this purpose, a support force of a support cylinder is recorded as a function of a support path and a code number is defined via an energy consumption derived therefrom. However, this figure has little informative value because a not negligible amount of energy that is lost in the system is not taken into account. In addition, the total energy actually introduced into the ballast during a tamping process would not be reliable Allow assessment of the condition of the ballast bed. In addition, in order to determine an energy-optimal amplitude or frequency, the superstructure must first be identified, which has a very time-consuming and costly effect on the tamping process.

Summary of the invention

The invention is based on the object of specifying an improvement over the prior art for a method and a device of the type mentioned at the beginning.

According to the invention, this object is achieved by a method according to claim 1 and a device according to claim 7. Dependent claims specify advantageous embodiments of the invention.

The method is characterized in that a course of at least one variable vibration magnitude is specified by means of a control as a function of a penetration time into the track ballast bed and that, in accordance with this predefined dependency, the vibration magnitude is automatically changed during a penetration process with increasing penetration time, until a required penetration depth of the tamping tools is achieved. In this way, energy-optimized penetration of the tamping tools is achieved. The vibration magnitude changes automatically with increasing penetration time, so that the penetration process is always coordinated with the actual ballast bed conditions. This means that it is not necessary to identify a superstructure and its bedding hardness or resistance in advance. Based on the penetration time, a conclusion is simply drawn about the hardness of the bedding.

In a simple version of the method, the vibration magnitude is changed for this purpose by means of a table and / or curve stored in a controller. This means that the vibration magnitude can be adjusted quickly with little computing power.

In addition, it is advantageous if the predefined dependency of the vibration magnitude on the penetration duration is changed in real time. In this way it is possible to react quickly to special conditions, for example by increasing the oscillation magnitude more quickly increasing penetration time. In addition, an operator of the work machine has the option of optimizing specifications for a tamping process in real time at any time.

A rising amplitude is advantageously specified as the oscillation variable. In the case of a loose ballast bedding (new layer) with little resistance, a low amplitude is sufficient for the tamping tools to penetrate. With this loose ballast bedding, no increase in amplitude is necessary. The mass of the tamping unit is sufficient to lower the tamping tools to the required working depth. With a hard ballast bedding (long lay time), the penetration of the tamping tools takes longer due to the higher resistance of the ballast. Depending on the duration of penetration, the amplitude is increased in order to counteract and overcome the higher penetration resistance.

Another improvement provides that a variable frequency is specified as the oscillation variable. A dependence of the frequency on the penetration time has an energy-optimizing effect on the tamping unit. For example, with a loose ballast bedding, a lower frequency can be maintained. Only for a hard ballast bedding will the frequency and thus the energy required increase with the duration of the penetration.

In addition, it is advantageous if the duration of penetration and the energy expended for penetration into the track ballast bed are recorded in an evaluation device. By recording the energy required for each penetration process, simple documentation is provided that can be used to further optimize the maintenance intervals.

The device according to the invention for performing one of the aforementioned methods comprises a tamping unit which comprises two opposing tamping tools which are each coupled via a swivel arm with an auxiliary drive and a vibration drive, with at least one vibration variable being dependent on the penetration time in a controller of the device.

It is advantageous if an evaluation device is provided for recording the duration of penetration and / or the energy used. Through the recording and evaluation, an energy balance of the tamping unit is further improved.

An additional development of the device provides that the control is designed to be adaptive in such a way that it allows previously recorded stuffing processes to flow into an energy optimization in order to automatically adapt the predefined dependency of the vibration magnitude on the penetration time for energy optimization. An intelligent control can, for example, be designed to be capable of learning in order to allow previously recorded stuffing processes to flow into the energy optimization.

In addition, it is advantageous if the control is coupled to an operating unit for changing the predefined dependency of the vibration magnitude on the penetration duration in real time. Thus, with each tamping process, the operator still has the option of intervening in a control of the tamping unit and thus the tamping process.

Brief description of the drawings

The invention is explained below by way of example with reference to the accompanying figures. It shows in a schematic representation:

Fig. 1

Tamping unit

Fig. 2

Diagram of optimized penetration behavior

Description of the embodiments

Fig. 1 shows a tamping unit 1, shown in simplified form, for tamping under a track ballast bed 2 below sleepers 3 of a track 4 with a lowerable tool carrier 5 and pairs of two opposite tamping tools 6. Each tamping tool 6 is connected via a swivel arm 7 to a hydraulic auxiliary drive 8, which at the same time acts as a vibration drive 9 is used. The respective swivel arm 7 has an upper swivel axis 10 on which the auxiliary drive 8 is mounted. The respective swivel arm 7 is rotatably mounted on the tool carrier 5 about a lower swivel axis 11. Such a tamping unit 1 is for Installation in a track 4 movable track tamping machine or a tamping satellite is planned.

In Fig. 2 an oscillation curve of a tamping tool 6 during a penetration process is shown in a diagram 12. The penetration time 13 is plotted on the abscissa axis. The ordinate axis indicates values for the oscillation deflections 14 (vibration) of the tamping tools 6. An envelope curve 15 of the oscillation deflections 14 shows a course of the oscillation amplitude 16. With this curve 15, the amplitude 16 is in the present example as a variable oscillation variable as a function of the penetration duration 13.

Specifically, as a function of the duration of penetration 13, the amplitude 16 is increased on the basis of the curve 15 until the required depth of penetration is reached (the amplitude 16 is a function of the duration of penetration 13). In this way, depending on the duration of penetration 13 and thus on the resistance of the ballast bed 2, the vibration amplitude 16 which is optimal in terms of energy is automatically specified. It is not necessary to identify the superstructure and its bedding hardness in advance. In the Fig. 2 The curve 15 shown has, for example, a linear course.

In the diagram, two vertical lines 17, 18 each show that the predetermined penetration depth has been reached. The first vertical line 17 corresponds to a loose ballast bed 2 with a low resistance. Here the penetration process is already completed after a short penetration time 13 while maintaining a small oscillation amplitude 16.

The second vertical line 18 corresponds to a hard ballast bed 2 with great resistance. Over the longer penetration time 13, the amplitude 16 increases in accordance with curve 15, until the penetration process is completed when the tamping tools 6 reach their maximum deflection. In the case of a harder ballast bed 2, the penetration process takes longer and the optimal amplitude 16 is automatically specified as a result.

For example, curve 15 is stored in a memory of a controller 19 as a function or in tabular form. A plurality of curves 15 can also be stored, whereby a selection can be made or curve parameters can be changed via an operating unit 20. With an intelligent control, there is the possibility of automatically making adjustments to the specified curve 15 in real time. For example, currently performed penetration processes are evaluated in order to optimize the energy expenditure for penetration of the tamping tools 6. Conclusions about the nature of the ballast bed 2 are also possible.

The adaptation of the predetermined curve 15 can also relate to the shape. For example, an increase start 21 and a rise end 22 of a linear increase in the oscillation amplitude 16 can be shifted. Non-linear changes in the vibration magnitudes can also be useful in order to react optimally to existing conditions (e.g. sinusoidal increase). In addition, mutually coordinated change specifications for the amplitude 16 and the frequency or period 23 are expedient in order to optimize the oscillatory movement of the tamping tools 6 during a penetration process.

p ₀... hydraulischer Versorgungsdruck [bar]
Q...notwendiger Volumenstrom der Beistellzylinder $\left[\frac{m^3}{s}\right].$

For this purpose, the device comprises an evaluation device 24 coupled to the controller 19. This evaluation device 24 is used, for example, to determine the energy required for a penetration process. In the case of hydraulic vibration generation by means of an auxiliary cylinder, the following relationship applies to the mechanical power: $${\mathrm{P.}}_{\mathit{mech}}={\mathrm{<figure-callout\; id="0"\; label="p"\; filenames="imgf0002.png"\; state="\{\{state\}\}">p</figure-callout>}}_0.Q$$

p ₀ ... hydraulic supply pressure [bar]
Q ... required volume flow of the auxiliary cylinder $\left[\frac{m^3}{s}\right].$

A_A...Große Fläche des Beistellzylinders, [m ²]
A_B ...Kleine Fläche des Beistellzylinders, [m ²]
a...Amplitude 16 des Beistellzylinders, [m]
f... Frequenz der Schwingungsbewegung, $\left[\frac{1}{s}\right]$

The volume flow of the auxiliary cylinders can be estimated using the following formula: $$Q=\left({\mathrm{A.}}_{\mathrm{A.}}+{\mathrm{A.}}_{\mathrm{B.}}\right).a.f$$

A _A ... Large area of the auxiliary cylinder, [ m ² ]
A _B ... Small area of the auxiliary cylinder, [ m ² ]
a ... amplitude 16 of the auxiliary cylinder, [m]
f ... frequency of the oscillation movement, $\left[\frac{1}{s}\right]$

t ₀...Beginn der Eindringdauer 13 [s]
t_tauch ...Ende der Eindringdauer 13 [s]The energy required for penetration per penetration process then results as follows: $${\mathrm{W.}}_{\mathit{ed}}={\displaystyle {\int }_{t_0}^{t_{\mathit{dive}}}{\mathrm{P.}}_{\mathit{mech}}.\mathit{German}}={\displaystyle {\int }_{t_0}^{t_{\mathit{dive}}}{p}_0\left({\mathrm{A.}}_{\mathrm{A.}}+{\mathrm{A.}}_{\mathrm{B.}}\right)a.f.\mathit{German}}$$

t ₀ ... start of penetration time 13 [s]
t _dive ... end of penetration time 13 [s]

In the case of tamping units with an eccentric drive for generating vibrations, the vibration frequency can first be set in the manner described above pretend. In the case of variants with an adjustable oscillation amplitude 16, this can also be specified as a function of the penetration duration 13 (see the applicant's Austrian patent application with the file number A 60/2017 or the application AT 517 999 A1 ).

Claims (10)

1. A method for compaction of a track ballast bed (2) by means of a tamping unit (1) comprising two oppositely positioned tamping tools (6) which, actuated with a vibration, are lowered into the track ballast bed (2) during a tamping operation and moved towards one another with a squeezing motion, characterized in that by means of a control system (19) a progression of at least one variable vibration parameter (16, 23) is specified in dependence on a duration of penetration (13) of the tamping tools (6) into the track ballast bed (2) and that according to this prescribed dependence the vibration parameter is changed automatically during a penetration operation with increasing duration of penetration until a required penetration depth of the tamping tools (6) has been reached.
2. A method according to claim 1, characterized in that the vibration parameter (16, 23) is changed by way of a chart and/or curve (15) stored in the control system (19).
3. A method according to claim 1 or 2, characterized in that the specified dependence of the vibration parameter (16, 23) on the duration of penetration (13) is changed in real time.
4. A method according to one of claims 1 to 3, characterized in that an increasing amplitude (16) is specified as vibration parameter.
5. A method according to one of claims 1 to 4, characterized in that a variable frequency or period time (23) s specified as vibration parameter.
6. A method for compaction of a track ballast bed according to one of claims 1 to 5, characterized in that the duration of penetration (13) and an energy expended for the penetration into the track ballast bed (2) are recorded in an evaluation device (24).
7. A device designed for performing a method according to one of claims 1 to 6, with a tamping unit (1) having two oppositely positioned tamping tools (6) which are each coupled via a pivot arm (7) to a squeezing drive (8) and a vibration drive (9), with a control system (19), characterized in that a dependence of at least one vibration parameter (16, 23) on a duration of penetration (13) is specified in the control system (19) of the device in such a way, that with increasing duration of penetration (13) of the tamping tools (6) into the track ballast bed (2) the progression of the vibration parameter (16, 23) changes automatically.
8. A device according to claim 7, characterized in that an evaluation device (24) is provided for recording the duration of penetration (13) and/or an energy expended.
9. A device according to claim 7 or 8, characterized in that the control system (19) is designed to be capable of learning in order to include previously recorded tamping operations in an energy optimization in order to automatically adapt the specified dependence of the vibration parameter (16, 23) on the duration of penetration (13) for energy optimization.
10. A device according to one of claims 7 to 9, characterized in that the control system (19) is coupled to an operating unit (20) for changing in real time the specified dependence of the vibration parameter (16, 23) on the duration of penetration (13).

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