Patent ID: 12195926

DESCRIPTION OF THE EMBODIMENTS

The working unit shown inFIG.1is configured as a tamping unit and includes an assembly frame2which is mounted via guides on a machine frame3of a track maintenance machine not further described. The working unit1serves for treatment of a track4having a ballast bed5on which sleepers6with rails7fastened thereon are supported. Specifically, the ballast bed5underneath the sleepers6is consolidated by means of the working unit1designed as a tamping unit. This is carried out in the case of new construction as well as during maintenance of a track4.

A tool carrier8is guided for vertical adjustment in the assembly frame2, wherein a lowering- or lifting motion takes place by means of an associated vertical adjustment drive9. Arranged on the tool carrier8is a vibration generator10to which at least two squeezing drives11are connected. Each squeezing drive11is connected to a pivot lever12of an associated tamping tool13. Both pivot levers12are mounted on the tool carrier8for movement towards one another about a respective separate pivot axis14.

The vibration generator10includes, for example, an eccentric shaft rotatable about a rotation axis, wherein the squeezing drives11are articulatedly connected to eccentric sections of said shaft. With the eccentric shaft rotating, the attachment points of the squeezing drives which circulate around the rotation axis cause a vibration transmission to the pivot levers12. In this, the eccentricity, advantageous adjustable, determines the vibration amplitude, and the rotational speed determines the vibration frequency.

A tamping tine is arranged at the free end of each tamping tool13. For a consolidation procedure, the tamping tools13—actuated with vibrations—are lowered into the ballast bed5. Underneath the sleeper lower edge, the tamping tines with their tine plates at the ends are squeezed towards one another by means of the squeezing drives11and thus consolidate the ballast support of the sleeper6.

According to the invention, the working unit1includes an electric drive15which, in the present example, powers the eccentric shaft. Especially well suited is a torque motor which is flange-connected to an eccenter housing, wherein the eccentric shaft is connected to the rotor of the torque motor. The torque motor is controlled by means of a control device16. The control device16also controls control valves of the hydraulic drives of the working unit1. In the present example, these are the vertical adjustment drive9and the squeezing drives11.

An evaluation device17is coupled to the control device16. This is, for example, an industrial computer which is designed for receiving and evaluating signals. At least one operating value18of the electric drive15is supplied to the evaluation device17. Said operating value18is provided either by the control device16or directly by the electric drive15.

During operation of the working unit1, the electric drive15effects the consolidation procedure at least partially, since the consolidation of the ballast bed5is influenced significantly by the vibrations of the tamping tools13. In addition, the consolidation depends on the present condition of the ballast bed5, i.e. on its quality or its physical characteristics. During this, counter forces of the ballast bed5act on the tamping tools13, as a result of which a reaction of the ballast bed5on the electric drive15takes place in further sequence.

In this, it is irrelevant that hydraulic components (squeezing drives11) are situated in the power path between the electric drive15and the tamping tools13. It is only essential that at least one operating value18of the electric drive15can be used for computing a ballast bed parameter19.

As a further example of a working unit1, a stabilizing unit is shown inFIG.2. It is arranged on a machine frame3of a track maintenance machine not further described. In working operations, the track grid formed of rails7and sleepers6is set in vibrations by means of the stabilizing unit. The vibrations are transmitted to the surrounding ballast bed5, as a result of which the same is consolidated. In this manner, a settling of the track grid is anticipated after a tamping procedure in order to be able to release the track4for standard operations right away.

This working unit1also includes an electric drive15of a vibration generator10. For example, a shaft with imbalances arranged thereon is powered. The vibrations are transmitted to the track grid by means of rail rollers20pressed to the rails7and propagate into the ballast bed5. In this, counter forces react on the track grid, as a result of which there is, in turn, a reaction of the quality and characteristics of the ballast bed5back on the electric drive15. For example, with equal impact force, the vibration amplitude depends on the already present ballast bed consolidation or on the transverse displacement resistance of the ballast bed5.

For control of the electric drive15, a suitable control device16is present, wherein the same is coupled to the evaluation device17for computing at least one ballast bed parameter19. For a computing procedure21, at least one operating value18of the electric drive15is supplied to the evaluation device17.

An advantageous computing method is described in more detail by way of the block diagram inFIG.3. At least one digital static or dynamic model22of a component of the working unit1is stored in a processor or a memory device. For example, a digital model22of an electric motor is stored for the electric drive15. By means of the digital model22, a model value23is computed from an operating value18.

Operating values18are, for example, an electric current, an electric voltage, a duty cycle, a magnetic potential difference, a magnetic penetration, a magnetic field strength, a magnetic flux, or a magnetic flux density. Model values derived from this are, for example, a moment, a force, a speed or angular speed, or an acceleration or angular acceleration. In the case of an electric drive15of a hydraulic pump, it is also possible to compute a pressure or a volume stream as a model value.

Specifically, a moment of the electric drive15can be computed from a rotary angle of the rotor and the measured currents with the aid of the digital motor model22. Furthermore, those forces acting directly on the ballast bed5can be computed from a speed or angular speed as well as from a driving force or a driving moment of the electric drive15with use of a mechanical model of the working unit1. From this, while taking account of the known dynamic forces, the forces reacting by the ballast bed5back on the working unit1ensue, which serve for deriving the ballast bed parameter19.

The computation of the model values23can take place in components provided especially for this, in the control device16or the evaluation device17, or in components provided for other tasks (for example, computation of the motor moment in the power electronics of the motor).

In the simplest case, a ballast bed parameter19is derived from only one operating value18of the electric drive15by way of the computation procedure21. To better evaluate the quality and the characteristics of the ballast bed5, however, it is advantageous if several model values23are used. The execution of the computation procedure21takes place by means of a processor. To that end, a computation software is installed in the processor which computes, on the basis of parameters of the working unit1and the track4as well as specific computing specifications, a parameter19from the input variables18,23.

An improvement of the computing procedure21is attained by taking into account measuring values24. The measuring values24are provided, for example, by a sensor or electronic technology25installed at the working unit1. For logical reasons, sensors and electric components already provided for other purposes are used. In addition, an operating value18can also be present as measuring value24if the electric drive15comprises a suitable sensor technology. For example, operating values18or model values23of the electric drive15and measuring values24are used to determine from this mechanical model values23of the working unit1.

The result of the computing process21is at least one ballast bed parameter19which serves for assessing the quality or the characteristics of the ballast bed5. For example, a parameter19is determined from the progression of a model value23or several model values23(speed progression, force progression, pressure progression . . . ) of the working unit1. Specifically, an energy consumption, extreme values of the forces and stiffnesses derived form a force-position progression can be formed as ballast bed parameters19.

For documentation of the track treatment, the evaluation device17is coupled to a recording device26. Advantageously, a momentary position of the working unit1is continuously reported to the recording device26. Thus, a progression of the found ballast bed parameters19is stored in a location-dependent way.