METHOD FOR CALIBRATING A DEVICE FOR MEASURING TRACKS

Abstract

A method for calibrating a device for measuring tracks having a track-driveable track-measuring car with a lifting and lining device and track-position measurement sensors measuring the height, direction and superelevation of the rails of the track using the machine frame as a reference zero line. A lifting and lowering device is associated with the track-measuring car. A calibration device is associated with the machine frame the track-measuring car, for calibrating the sensors, is first lowered from a parking position, in which the track-measuring car is lifted from the track, onto the track or into an intermediate position. Calibration stops are moved by an actuator from an idle position into a calibration position, against which the track-measuring car is subsequently raised and applied. The values of the track-position measurement sensors are read out and stored in the measurement system as calibration values, and the track-measuring car is lowered onto the track.

Claims

1. A method for calibrating a device for measuring tracks having at least one track-driveable track-measuring car associated with a lifting and lining device, and comprising track-position measurement sensors configured to measure a height position, a direction and a superelevation of rails of the track using a machine frame as a reference zero line, wherein a measuring-car lifting and lowering device is associated with the track-measuring car, said method comprising: providing a calibration device associated with the machine frame, lowering the track-measuring car, for the purpose of calibrating the track-position measurement sensors from a parking position, in which the track-measuring car is lifted from the track, onto the track or into an intermediate position, moving calibration stops by an actuator from an idle position into a calibration position, raising and applying the track measuring car against the calibration stops, reading out resulting values of the track-position measurement sensors, reading the resulting values into the measurement system and storing the resulting values as calibration values, and lowering the track-measuring car onto the track.

2. A method according to claim 1, wherein the track-measuring car, in the calibrating position, is pressed in a first step on a machine frame side in a direction of a transverse axis of the track-measuring car via a pressing apparatus with a wheel flange against the associated calibration stop and wherein the track-position measurement sensors include a standard value measuring sensor and a levelling value measuring sensor produce respective resulting measurement values each of which is read into and stored in the measuring system as a zero calibration value for said machine frame side, and wherein that the track-measuring car is subsequently pressed in a second step on an opposite machine frame side in an opposite direction opposite to said direction of the transverse axis of the track-measuring car via the pressing apparatus with another wheel flange against the associated calibration stop; and wherein another resulting measurement value on the standard value measuring sensor is read into and stored in the measuring system as a zero calibration value for said opposite machine frame side.

3. A method according to claim 1, wherein the value of the reference superelevation measured value measured on the machine frame is associated with the actual superelevation measured value measured during calibration on the measuring car.

4. A method according to claim 1, wherein the method steps are carried out in an automated manner by a control program.

5. A device for measuring tracks, said device comprising: at least one track-driveable track-measuring car associated with a lifting and lining device, and track-position measurement sensors measuring a height position, And superelevation of the rails of the track using a machine frame as a reference zero line, wherein a measuring-car lifting and lowering device is associated with the track-measuring car, wherein the machine frame is associated with a calibration device with calibration stops, which are movable from an idle position to a calibration position by an actuator used when calibrating the track-position measurement sensors, and the track-measuring car engaging against said calibration stops when the track-measuring car is raised after the track-measuring car is moved onto the track from a parking position lifted from the track or lowered into an intermediate position, and wherein the calibration stops form attachment points for the measuring car applied by the measuring-car lifting and lowering apparatus against the calibration stops.

6. A method according to claim 1, wherein, after said lowering of the track-measuring car onto the track, the actuator moves the calibration stops from the calibration position thereof to the idle position thereof.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The subject matter of the invention is shown in the drawings by way of example, wherein:

[0014] FIG. 1 shows a track tamping machine with a track tamping unit, a track lifting/lining unit, a levelling measurement system and a track lining measurement system in a side view;

[0015] FIG. 2 shows an illustration in accordance with the invention of the calibration device with the measuring car in a cross-sectional view;

[0016] FIG. 3 shows a section with a calibration stop of FIG. 2 in an enlarged detailed view;

[0017] FIG. 4 shows a schematic levelling measurement system with a machine frame reference line and a calibration reference line as well as calibration stops, and

[0018] FIG. 5 shows the schematic lining measurement system with the machine reference line and the calibration reference line, as well as a calibration stops to the left and the right of the machine frame.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0019] A track tamping machine 1 (FIG. 1) comprises a tamping unit 26 and a track lifting/lining unit 25. The machine frame 13 is used as a reference for absolute zero calibration. The lining unit consists of a lining steel cord 12, the three measuring cars 4 and a lining transducer 11. The levelling unit consists of two steel cords 16 which are tensioned over the rails, two levelling transducers 17 with steel cord acquisition sensors 19 and the levelling rods 14. The track tamping machine 1 travels on undercarriages on the rails 3.

[0020] Sensors for measuring the height position (levelling transducers 17), the direction (lining transducers 11), and the superelevation (inclinometers 25) are provided as track position measurement sensors for measuring the rails of a track (3, 28). The track-measuring car 4 is associated with a measuring-car lifting and lowering apparatus 9.

[0021] The machine frame 13 is associated with a calibration apparatus 2 with calibration stops 5, which can be moved onto the track from a parking position lifted from the track or a track-measuring car 4 lowered to an intermediate position for calibrating the track position measurement sensors with an actuator from an idle position to a calibration position, and against which the track-measuring car 4 can subsequently be lifted and applied. The calibration stops 5 form the attachment points for the measuring car applied with the measuring-car lifting apparatus 9 against the calibration stops 5 (FIG. 2).

[0022] In the case of an embodiment of the absolute calibration device 2 in accordance with the invention (FIG. 2), the machine frame 13 is used as a related reference. Calibration stops 7, which are adjustable in alignment in the longitudinal direction, are attached to the machine frame (adjustment via a thread and fixed via lock nuts for example). The calibration levers with the calibration stops 5 are pivoted inwardly or outwardly up to said stops via hydraulic calibration cylinders 8, i.e. they are displaced from their idle position to their calibration position. The height position of the calibration stop 5 can be adjusted via an adjusting device 6 (a threaded tube which connects the upper and bottom lever arm via a thread, wherein a left-hand thread is situated at the top for example and a right-hand thread at the bottom). The measuring wheel 4 is pressed upwardly via the measuring-car lifting cylinders 9 and the pressing cylinders 10 to the side against the respective calibration stop 5. A lining transducer 11 is attached to the measuring car, which lining transducer measures the lateral position of the lining cable 12 via a carrier. An inclinometer 25 is also disposed on the measuring car. A reference inclinometer 23 is disposed on the machine frame 13 as a reference for said inclinometer. In order to perform pressing to the left, both measuring-car lifting cylinders are switched to “lifting” (force F.sub.LH and F.sub.RH acting in the upward direction), and the pressing cylinder is switched to left action to pressing (force F.sub.LA) and the pressing cylinder to the right is switched to powerless mode. For calibrating the right side, the right pressing cylinder is pressurised (force F.sub.RA) and the left is switched to powerless mode. The rails 3 are mounted on the track ties 28.

[0023] The calibration stop 5 rests laterally on the contact point at height D (usually 14 mm) (FIG. 3). The horizontal force F.sub.Q and the vertical force F.sub.V are acting.

[0024] FIG. 4 schematically shows the levelling system which consists of the levelling rods 14, the levelling transducer 17, the carrier 19, the levelling cord 16, a cord tensioning apparatus 18 and the measuring car 4. The reference line 15 of the absolute zero calibration apparatus in accordance with the invention lies parallel to the machine reference line 15. The wheels 4 are pressed with respect to height against the calibration stops 5. A track error 20 shows that the calibration with the measuring car 4 lowered onto the track 3 would be erroneous.

[0025] FIG. 5 schematically shows the embodiment in accordance with the invention of the absolute zero calibration for the lining measurement system. The measuring wheels 4 at the top are pressed against the calibration stops 5. The reference lines of the calibration device (dot-dash lines) are parallel to the machine reference line 22. Reference numeral 24 shows a mechanical lateral cord adjusting device which can be used for scale factor determination. The lining transducer 11 is installed on the middle measuring car 4, which transducer measures the lateral deflection of the lining cord 12. The lining cord 12 is tensioned by a tensioning apparatus 18. If the zero calibration were carried out with the measuring car 4 lowered onto the track 3, then it would be determined erroneously by the track error 21.