EP3953527B1 - Tamping pick - Google Patents

Description

field of technology

The invention relates to a tamping pick for a tamping machine for tamping a track, with a pick shaft which has a holding section for fastening in a pick holder at its upper end and which merges into a pick plate at its lower end.

State of the art

For example, the WO 2011/003427 A1 a tamping pick for a tamping machine for tamping a track. The tamping machine includes tamping tools with tine receptacles for clamping a respective tamping tine.

From the WO 2018/219570 A1 a method for compacting a track ballast bed using a tamping machine is known. In this case, force measuring sensors are arranged on the tine receptacles of a tamping unit in order to record a course of a force acting on the tamping tool over a path covered by the tamping tool during an oscillation cycle. As an alternative to this, strain gauges can be glued to an outer surface of the respective tamping tine. The disadvantages here are the insufficient durability and the complicated and cost-intensive application. JP-A-351149605 discloses a generic tamping pick with the features of the preamble of claim 1.

Presentation of the invention

The invention is based on the object of specifying a tamping tool of the type mentioned at the outset, with which an improved tamping process can be carried out is feasible.

According to the invention, this object is achieved by the features of independent claim 1. Dependent claims specify advantageous refinements of the invention.

A sensitive element of a sensor is arranged in a recess in the shaft of the tine and the tamping tine includes a coupling element for transmitting a sensor signal. In this way, the tamping tine itself fulfills a sensor function for detecting a measured variable occurring in the tamping tine. The arrangement of the sensitive element is optimal because the recess in the shaft of the pick is adapted to the properties of the sensor. The desired measured values can be recorded with a high level of accuracy, with the integration of the sensitive element in the shaft of the pick preventing interference from being influenced. In addition, the arrangement protects the sensitive element from damage.

In an advantageous development, the tamping tine includes electronics of the sensor. Thus, for example, before delivery of the tamping tine, the sensor or the sensitive element can be calibrated, calibration data being able to be stored in the electronics. Advantageously, the electronics include a memory chip whose connection is routed to the outside via a cable.

A further improvement provides that the sensitive element is designed to record several measured variables occurring in the tamping tine. For example, the temperature of the tamping tine is recorded in addition to mechanical stress. In this way, the sensor is suitable for monitoring operating conditions during a tamping process in order to derive maintenance requirements from them.

For a simple replacement of a tamping pick, it is advantageous if the coupling element is an element of a detachable plug connection. When changing the tamping tool, the plug connection is released and the tamping tool goes through replaced with a new tamping tool. The new tamping tool uses the same plug-in connection to restore the plug-in connection.

To ensure compatibility, the tamping tool includes an electronic component for identifying the tamping tool. Conveniently, this is a so-called trusted platform module, which prevents manipulation of the identification.

In an advantageous embodiment of the tamping tool, the sensitive element is an expansion element glued into the recess. In this way, forces and accelerations acting on the tamping tine can be easily detected.

A further improvement provides that the sensitive element is an optical waveguide with a fiber Bragg grating. Such a fiber Bragg grating can be used to measure elongations, compressions and bends at predetermined points in the optical waveguide. Forces, accelerations and temperature changes can be derived from this.

In this case, it is advantageous if the optical waveguide protrudes from the recess in the shaft of the pick and that the protruding section of the optical waveguide is encased in a flexible protective sleeve. In this way, the optical waveguide with the protective sheathing is guided to a point where evaluation electronics are arranged.

According to the invention, the recess is designed as a longitudinal bore in a core area of the pick shaft. The sensitive sensor element is then optimally protected against damage without adversely affecting the strength of the ax shaft. A mechanical protection against buckling is optionally arranged at an exit point.

In the tamping machine for tamping a track, opposite tamping tools can be subjected to vibration and are mounted on a height-adjustable tool carrier so that they can be placed next to one another, with the respective tamping tool comprising a pick receptacle in which a tamping pick described above is fastened and with an evaluation device being coupled to the sensor of the respective tamping pick . Measured variables occurring in the tamping picks during a tamping process can thus be recorded in order to optimize the tamping process.

It is advantageous if the evaluation device is connected to the respective sensor by means of a plug-in connection and if the respective plug-in connection is arranged in particular on the tool carrier. This simplifies the replacement of a tamping tine without impairing the measurement value acquisition.

A method for operating the described tamping machine with the described tamping picks provides that during a tamping operation a measured variable occurring in the respective tamping pick is detected by the assigned sensor and registered by the evaluation device. This means that the measured values recorded during a tamping process can be used to optimize subsequent tamping processes. In addition, the tamping quality and the loads that occur can be documented.

In an improved method, a calibration process is carried out for each sensor before a stuffing process, in order to determine calibration values. This recurring renewal of the calibration values ensures that each sensor works with the greatest possible accuracy at all times.

A further improvement of the method provides that, before a tamping process, a readout process is started for each tamping tool and that the tamping process is blocked if the electronic component for identifying the respective tamping tool is missing or incorrect. This prevents the tamping machine from being operated with the wrong tamping tool. Using the wrong tamping tools can result in poor tamping quality or excessive wear. In addition, incorrect tamping tools cannot be used for the measurement value acquisition according to the invention.

In order to be able to query the current status of the tamping machine at any time, it is advantageous if a change of a tamping tine is registered by means of the evaluation device. Corresponding status data can also be transmitted to a cloud in order to log every change process.

Brief description of the drawings

Fig. 1

Stopfmaschine

Fig. 2

Stopfaggregat

Fig. 3

Stopfpickel mit Längsbohrung

Fig. 4

Stopfpickel mit sensitivem Element und Koppelelement

Fig. 5

Stopfpickel in einer Pickelaufnahme

The invention is explained below in an exemplary manner with reference to the attached figures. They show in a schematic representation:

1

tamping machine

2

tamping unit

3

Tamping tool with longitudinal bore

4

Tamping tool with sensitive element and coupling element

figure 5

Tamping tine in a tine receptacle

Description of the embodiments

In the 1 The tamping machine 1 shown can be moved with rail chassis 2 on a track 3 to be tamped and comprises a tamping unit 4, a lifting/aligning unit 5, a measuring system 6 and a machine control 7. The track 3 is a ballasted track, in which a sleeper 8 and rails 9 formed track grid is stored in a ballast bed 10. During a tamping operation, the track panel is lifted into a desired position by means of the lifting/straightening unit 5 and, if necessary, shifted to the side. A comparison of the current position of the track panel with the target position is carried out using the measuring system 6.

The target position is fixed by the tamping unit 2 penetrating with vibrating tamping picks 11 between the sleepers 8 into the ballast bed 10 and compacting the ballast under the sleepers 8 with a lateral movement. The lifting/straightening unit 5 and the tamping unit 4 are controlled by the machine control 7 using the measuring system 6.

Each tamping pick 11 is fixed in a pick receptacle 12 of a tamping tool 13 . For this purpose, a tine shaft 14 of the respective tamping tine 11 has a holding section 15 at its upper end, which is inserted in the tine receptacle 12 . For example, the holding section 15 is cylindrical and forms a fit with a cylindrical inner surface of the tool holder 12 . The holding section 15 is clamped in the tool holder 12 by means of screw connections. At its lower end, the pick shaft 14 merges into a pick plate 16 .

Opposite tamping tools 13 are mounted in the form of tongs on a common tool carrier 17 . The tool carrier 17 is guided in a unit frame 18 so that it can be adjusted in height. Upper ends of the tamping tools 13 are connected to a vibration generator 20 via respective auxiliary drives 19 . For example, the auxiliary drives 19 are mounted on a rotating eccentric shaft. In an alternative embodiment, the generation of vibrations is integrated in the respective auxiliary drive 19 . In this case, cyclic vibration strokes are superimposed on an auxiliary stroke in a hydraulic cylinder.

In order to monitor the quality of a tamping process and, if necessary, to influence it, at least one measured variable occurring in a tamping pick 11 is recorded. For this purpose, a sensitive element 22 of a sensor 23 is arranged in a recess 21 of the pick shaft 14 . The measured variable is supplied to an evaluation device 25 via a coupling element 24 connected to the sensitive element 22 . in the in 2 illustrated variant, the evaluation device 25 is connected to the respective sensor 23 by means of a plug connection 26 . The evaluation device 25 is set up in the machine controller 7, for example.

The sensitive element 22 is advantageously an optical waveguide with a fiber Bragg grating. The section with the fiber Bragg grating is glued into the recess 21 of the shaft 14 of the pick. In this way, expansions, compressions or bends in the pick shaft 14 are transmitted to the optical waveguide. The optical waveguide is guided out of the pick shaft 14 at a recess opening 27 . Mechanical protection is advantageously arranged here in order to avoid damage to the optical waveguide. In the example according to 2 forms the protruding section of the optical waveguide with the connection to sensor electronics 28, the coupling element 24. This section is covered with a flexible protective sleeve (eg armored hose).

The elongations, compressions and bends of the pick shaft 14 detected by the fiber optic sensor 23 are subsequently evaluated. For example, forces, accelerations and temperature changes are calculated therefrom in the evaluation device 25 . Also Further measurement variables can be derived from the measurement signals by means of the sensor electronics 28 . The basis for this is a preceding calibration process.

The sensor 23 is calibrated, for example, by the manufacturer before delivery. The calibration data are stored in the sensor 23 or in a separate storage element. Conveniently, a memory chip 29 is glued into the tamping pick 11, the connection of which is routed to the outside via a cable. In an alternative wireless sensor 23, the memory chip data is read out by means of a reading device, which can be stationary or mobile. The data are transmitted to the machine control 7 via a radio interface.

As an alternative or in addition to the initial calibration, an automatic calibration program is run before each use of the machine. Calibration values are determined for each tamping tine. The updated values are stored in memory chip 29.

The tamping tine 11 expediently comprises a further electronic component 30 which enables the tamping tine 11 to be identified electronically. For example, a so-called trusted platform module is implemented, which ensures that the tamping tool 11 is identified in a way that is secure against forgery. The memory chip 29 and the electronic component 30 are favorably integrated in the sensor electronics 28 .

The machine control 7 is set up in such a way that a readout process is started after the machine 1 has been started up and before a first tamping process is carried out. If the respective electronic component 30 is missing or no identification of the respective tamping tool 11 is possible, the tamping process is blocked. This prevents a tamping process from being carried out with the wrong tamping tools. The readout process can also be used to log a tamping tine exchange.

In 3 the recess 21 according to the invention is shown as a longitudinal bore in a core area of the pick shaft 14 . This does not weaken the pickaxe shank 14 because the area moment of inertia of the shank cross section is only slightly affected. The longitudinal bore extends approximately to the pick plate 16. Thus, counteracting forces of the pick plate 16 acting Ballast bed 10 with a fiber Bragg grating at the end of a glued-in optical waveguide can be detected directly. In a simpler variant, the recess 21 is designed as a groove along the pick shaft 14, the groove being sealed after the sensitive element 22 has been introduced.

A depression for the sensor electronics 28 is provided in the area of the recess opening 27 . In this case, the memory chip 29 and the electronic component 30 as well as plug contacts 31 are also housed in a glued-in electronics housing ( 4 ). In this embodiment, the tamping tine 11 includes the entire sensor 23.

When the tamping tool 11 is installed, the plug contacts 31 are connected to the contacts of the tool holder 12 ( figure 5 ). This plug-in connection 26 is arranged in a protected manner in the tine receptacle 12 and connects the sensor 23 to the evaluation device 25 attached to the tamping tool 13. A connection to the machine controller 7 is established via a cable or via a radio interface.

The direct detection of mechanical forces, vibrations and, if necessary, the temperature in the tamping picks 11 enables ongoing status monitoring. First of all, this relates to the condition of the processed ballast bed 10. From this, adapted control parameters can be derived in order to adapt the tamping process to the respective ballast bed condition. This takes place automatically in the machine control 7 based on all sensor data and leads to an optimized control of the unit drives.

In addition to detecting the condition of the ballast bed 10, the sensors 23 are used to record the individual tamping processes. It makes sense if ranges are specified for individual measured variables in order to identify unwanted deviations at an early stage. In this way, operating errors and progressive signs of wear can be detected (condition monitoring). An evaluation of the log data enables predictive maintenance of the wear parts, in particular the tamping pick 11 (predictive maintenance).

Claims (4)

1. Tamping tine (11) for a tamping machine (1) for tamping a track (3), including a tine shaft (14) which has at its upper end a retaining portion (15) for fastening in a tine mount (12) and which merges at its lower end into a tine plate (16), that a sensitive element (22) of a sensor (23) is arranged in a recess (21) of the tine shaft (14), and that the tamping tine (11) includes a coupling element (24) for transmission of a sensor signal, characterized in, that the recess (21) is formed as a longitudinal bore in a core section of the tine shaft (14).
2. Tamping tine (11) according to claim 1, characterized in that the sensitive element (22) is a strain element glued into the recess (21).
3. Tamping tine (11) according to claim 1, characterized in that the sensitive element (22) is a fibre optic cable with a fibre Bragg grating.
4. Tamping tine (11) according to claim 3, characterized in that the fibre optic cable protrudes from the recess (21) of the tine shaft (14), and that the protruding portion of the fibre optic cable is sheathed by a flexible protective cover.

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