SYSTEM WITH A DEVICE FOR DETECTING SEIZING BRAKES AND / OR OVERHEATING RUNNERS IN RAIL VEHICLES AND METHOD FOR MONITORING SUCH A SYSTEM

Description

[0001] The present invention relates to a system with a device for detecting stuck brakes and / or hot box axles in rail vehicles. It also relates to a method for monitoring such a system.

[0002] Such devices are known, for example, from DE 100 60 380 A1, DE 10 2010 009 754 A1, and WO 2014 / 082675 A1. They typically comprise a hollow steel measuring sleeper that is inserted into the track bed instead of a conventional concrete, wooden, steel, or plastic rail. It is partially designed as a housing for accommodating, in particular, infrared sensors for measuring the temperature of wheelset bearings and brakes, as well as an evaluation unit for evaluating the sensor signals.

[0003] From DE 10 2005 024 852 A1 a system is known in which the infrared sensors are mounted in housings on the top side of a hollow sleeper and are connected via cable connections to a control and evaluation unit arranged in the hollow sleeper.

[0004] Such measuring sleepers designed as hollow sleepers have the disadvantage that the replacement of the conventional sleeper with the measuring sleeper is relatively time-consuming, since after the already time-consuming replacement, it is typically necessary to re-tamp the ballast.

[0005] In alternative systems, housings with infrared temperature sensors are mounted between the sleepers using a bracket that can be attached to the tops of two adjacent sleepers. This variant has the disadvantage that the brackets, along with the brake-lock and / or hot-box detection devices, must be removed each time before mechanical ballast tamping is performed.

[0006] EP 3 527 459 A1 discloses a device for detecting derailments of rail vehicles, which device has acceleration sensors arranged on a sleeper.

[0007] The present invention is based on the object of specifying a system with a device for detecting stuck brakes and / or hot box axles in rail vehicles, wherein the device can be installed particularly quickly and easily and does not hinder maintenance and repair work on the track bed.

[0008] This problem is solved by the subject matter of independent patent claim 1.

[0009] Advantageous embodiments and further developments are the subject of the subclaims.

[0010] According to one aspect of the invention, a system is provided with at least one solid sleeper for supporting rails for rail vehicles and at least one device for detecting hard brakes and / or hot box axles in rail vehicles, wherein the device is mounted on an upper side of the sleeper, with a housing mounted on an upper side of the solid sleeper and below a rail top edge, wherein at least one infrared temperature sensor and an evaluation unit connected to the at least one infrared temperature sensor for evaluating sensor data are arranged in the housing.

[0011] A solid sleeper is understood here and below to mean a sleeper that is conventionally constructed from wood, concrete, steel, plastic, or another material and does not have a hollow space to accommodate components of a system for detecting dead brakes and / or hot box axles on rail vehicles. The device is therefore mounted on top of a conventional sleeper and does not protrude into the sleeper. Furthermore, the housing does not protrude beyond the top edge of the rail; in particular, the overall height of the at least one housing does not exceed 159 mm, and in particular, it does not exceed 140 mm.

[0012] Furthermore, the housing has a base surface facing the top of the sleeper, which does not protrude significantly beyond the sleeper at the sides. This is understood here and in the following as meaning that the base surface does not protrude beyond the sleeper at the sides by more than 2 cm, preferably not more than 1 cm, and in particular not at all. A slight overhang of 1-2 cm can be tolerated because the housing does not interfere with the ballast filling.

[0013] The evaluation of measured data is understood here and below to mean preliminary evaluation or data processing. The evaluation of the measured data is typically not carried out exclusively by the device installed in the track bed, but to a certain extent in an external device, which may in particular have the task of summarizing measured data from various devices and evaluating them in relation to the entire train. The evaluation unit of the device can in particular have the task of temporarily storing the measured values ​​from the sensor and / or amplifying them and / or processing them and / or making them available to an external unit. In particular, the evaluation unit arranged in the housing can compare the measured values ​​with limit values ​​and can also reduce and compress the data.

[0014] The data processed in this way is then available to an external unit, which is a component of the system for hard brake and / or hot box detection. It receives and aggregates data from multiple devices and evaluates it. This unit is also referred to here and below as the central storage and processing unit. The external unit is also located on top of a solid sleeper or further away in or next to the track bed, but not in a hollow sleeper. Accordingly, the device is not connected to the external unit via a cable leading through the housing base into the sleeper, but via cables laid on the sleeper and in the track bed, or via a wireless connection.

[0015] The external unit may, in particular, have the tasks of allocating the measured values ​​to individual wagons, logically checking the measured values, logically checking alarm values ​​and, for example, not issuing them if system components are identified as defective, storing measured data, summarising all measured data into train measured values ​​and monitoring the temperature limit values, which may be set differently depending on the train type.

[0016] According to one concept underlying the invention, all elements of a system for detecting stuck brakes and / or hot box axles on rail vehicles can be accommodated on top of one or more solid sleepers, eliminating the need to install a hollow sleeper as a measuring sleeper. This has the advantage of saving considerable time during installation of the device, as the time-consuming and costly replacement of the conventional sleeper with a special measuring sleeper is eliminated. Furthermore, the device has the advantage that the housing does not protrude significantly beyond the sleeper at the sides, meaning it does not get in the way and would not have to be removed if the ballast were to be mechanically tamped.

[0017] This can be achieved, in particular, by ensuring that the dimensions of the base area of ​​the housing in a longitudinal direction do not exceed 310 mm, in particular 300 mm. The longitudinal direction is defined here and below as the direction parallel to the rail and thus as the direction of travel of a rail vehicle.

[0018] The device thus forms a compact unit, also known as a scanner, of a system for detecting stuck brakes and / or hot box axles, mounted on the sleeper. The system for detecting stuck brakes and / or hot box axles can comprise several such scanners or devices, as well as a central storage and processing unit and, if necessary, train presence detection devices arranged separately from the scanner. All elements of the system can be mounted on top of solid sleepers.

[0019] The desired low overall height of the device can be achieved, in particular, through compact components and a particularly space-saving arrangement. In particular, the central components, especially the optics module, lid motor, fan, and infrared reference system, can be arranged side by side or one behind the other on a single mounting plate instead of one above the other. An electrically insulating material such as fiberglass can be chosen for the mounting plate, eliminating the need for additional insulating elements or layers.

[0020] According to one embodiment, the device further comprises an acceleration measurement device mechanically connected to the housing, in particular undamped or with a known damping. The acceleration measurement device can be used, in particular, to monitor the infrared sensors and / or the evaluation unit for vibration-induced stresses. To protect these devices, the housing is typically connected to the sleeper by means of a damper system. If the damper system is defective, the device for detecting stuck brakes and / or hot box axles is exposed to considerable stress from acceleration forces, which can cause premature aging.

[0021] According to the invention, the housing has a ground clearance on its underside on a side closest to the rail. In the area of ​​the ground clearance, the housing has a difference h 2 between its top and its bottom—spaced from the sleeper when installed—while it has a difference h 1 in other areas far from the rail. h 1 and h 2 are therefore the housing heights in the two housing sections. In particular, the ratio of these heights is h 2 / h 1 ≤ 0.8, especially ≤ 0.7.

[0022] In particular, the housing can have a stepped housing base contour in cross-section, which is aligned in such a way that the housing has ground clearance on its underside on its side near the rail.

[0023] In other words, the housing base has a stepped cross-section in the longitudinal direction of the threshold.

[0024] The housing section having the ground clearance may extend over half the base area of ​​the housing or less, in particular 0.125 A ≤ A 2 ≤ 0.5 A, where A is the total housing base area and A 2 is the base area of ​​the housing section having the ground clearance.

[0025] This design has the advantage that the housing can be mounted relatively close to the rail. This is typically not possible without the ground clearance described, as the mounting screws for attaching the rail to the sleeper would be in the way. However, the ground clearance allows the housing to be partially slid over the mounting screws.

[0026] According to one embodiment, the housing has at least one window for the entry of infrared radiation, wherein the window is arranged on the side of the housing closest to the rail and at ground clearance. The window is provided in a housing cover opposite the housing base.

[0027] This embodiment has the advantage that the design of the device allows temperature measurement both near the rail, when the housing is mounted close to the rail, and at a somewhat greater distance from the rail, when the housing is mounted further out. This allows the device to be used flexibly with various rail and wheel systems. Since the systems used are not internationally standardized, it has so far been necessary to adapt the position of the infrared temperature sensors to the respective system. This ensures that the temperature measurement can be taken vertically upwards, because an inclined temperature measurement is subject to inaccuracies due to different wheel sizes. The ground clearance of the housing therefore allows for particularly flexible use of the device.

[0028] To take advantage of temperature measurement near the rails, the device's optical module is advantageously designed to be particularly flat, allowing it to be housed in the housing section with the lower height h 2 and thus close to the rails. For this purpose, it has proven advantageous to arrange other components of the device, which were previously located below the optical module, to the side of the optical module.

[0029] The optics module typically comprises at least one infrared sensor and at least one rotating mirror that deflects the incoming infrared radiation around the infrared sensor, as well as a rotating mirror motor that rotates the rotating mirror for cleaning purposes, and the control electronics of the infrared sensor.

[0030] A drive for opening and closing a cover (cover motor) is advantageously arranged next to the optics module, where "next to" here refers to an arrangement in which the components are arranged next to one another in a horizontal plane of the housing, possibly offset in height due to the stepped housing base contour. In particular, both the optics module and the cover motor can be arranged on the bottom of the housing, with the cover motor being arranged in the housing section with the greater height h 1 . An infrared reference system can also be arranged next to the optics module, but depending on the available installation space, also in the housing section with the lower height h 2 .

[0031] According to one embodiment, an acoustic sensor unit for receiving sound signals is arranged in the housing. Such a sensor unit enables the detection and evaluation of acoustic anomalies in acoustic signals emanating from wheels, wheel bearings, and braking systems that indicate damage. In particular, the acoustic signals can also be used to detect wheel defects such as flat spots, polygonization, flattening, and chipping at an early stage.

[0032] As it turns out, damage can be detected in this way long before the component fails, so that the acoustic sensor unit can be used as an early warning system. Its functionality can be regularly monitored using internal acoustic testing. Arranging the acoustic sensor unit within the housing has the advantage that only a compact housing needs to be installed. Furthermore, the close connection also allows for easy linking of the measurement data from the at least one infrared temperature sensor and that of the acoustic sensor system. Furthermore, the acoustic sensor unit can be used to acoustically monitor the device itself, in particular the motor of a rotating mirror, if one is used for beam deflection, the rotating mirror itself, an infrared reference system with a magnet or stepper motor, and the opening and closing movement of a cover.If the noise generated by one of these components changes or if new noises occur, a corresponding technical message or alarm can be issued as a preventive warning.

[0033] According to one embodiment, a device for determining the position of the housing is arranged in the housing. The device for determining the position of the housing can, in particular, comprise a satellite navigation device and / or an inclination sensor.

[0034] This embodiment has the advantage that the position or positions of the housing can be continuously monitored. If the device for determining the position of the housing comprises at least one inclination sensor, the data from the inclination sensor can easily be used to determine whether the housing has been tilted or removed due to an accident. If the device for determining the position of the housing comprises a satellite navigation device, a measured value from the temperature sensor arranged in the housing can be unequivocally assigned to the right or left side of the rails or to the center. This is particularly helpful because if the housings are mixed up during installation on the sleeper, sensor data would otherwise be assigned to the wrong wheel side of the rail vehicle, making troubleshooting futile or costly.

[0035] The satellite navigation device may in particular be a device that uses the signals from GPS, Galileo or GLONASS satellites to determine the position.

[0036] According to the invention, the device is mounted on the upper side of the sleeper and thus does not protrude into the sleeper. The system can comprise several devices that can independently collect, process, and store measurement data and make it available to a central storage and processing unit that is also part of the system, which then, for example, aggregates the measurement data at the train level as already described. According to one embodiment, the housing of the at least one device is mounted on the sleeper by means of a connecting piece.

[0037] The connecting piece is typically a separate component or bracket that is glued, clamped, or screwed onto the sleeper. The connecting piece can be designed as a kind of covering for the entire sleeper, onto which all the housings of several devices can be pre-mounted. In this case, only the connecting piece needs to be mounted to the sleeper in the track, which saves a considerable amount of time. However, a connecting piece can also be provided for each device.

[0038] The connecting piece can, in particular, be designed in such a way that it can remain permanently attached to the threshold, and the device, along with an associated damping system, simply needs to be inserted or placed on top and, if necessary, secured with a few fastening elements, such as screws. This has the advantage that the device can only be connected to the connecting piece in a specific way, thus avoiding incorrect assembly, for example, in the event of a replacement or repair.

[0039] A damping system can be provided as an integral part of the device to protect the device from high mechanical stresses caused by vibrations. For this purpose, at least one damping element, such as a rubber element or a spring, can be arranged between the housing and the connecting piece. For example, a damping element can be provided at each attachment point of the housing on the connecting piece. In particular, damping elements can be formed as an integral part of the device and thus connected to the housing before installation on the sleeper.

[0040] According to one embodiment, the system further comprises a device for measuring acceleration, comprising at least one first acceleration sensor connected to the housing mechanically and in particular undamped or with known damping, and at least one second acceleration sensor connected to the threshold mechanically and in particular undamped or with known damping.

[0041] This embodiment has the advantage of allowing very extensive monitoring of the condition of both the system and the ballast, as well as the wheels of the rail vehicles. If the acceleration sensors deliver unexpectedly high measured values, there can be various reasons for this: there may be a flat spot on the wheel of a passing rail vehicle, there may be poorly tamped ballast, or there could be a defect in the device's damping system. Using the first and second acceleration sensors, it is possible to distinguish between these three cases: A flat spot can be detected if the acceleration sensor on the rail / sleeper only responds for some wheels. A defective damping system can be detected if the at least one acceleration sensor on the rail / sleeper and the acceleration sensor on the housing show very similar measured values.A poorly tamped sleeper can be detected by the acceleration sensor on the rail / sleeper measuring high accelerations for all wheels and the signal showing the frequency of passing the wheels.

[0042] To enable a particularly precise differentiation of such cases, the first acceleration sensors and the at least one second acceleration sensor can have different measuring ranges. Since only low accelerations should occur in the housings with an intact damper system, the first acceleration sensors can be designed as relatively sensitive sensors. However, the second acceleration sensors connected to the threshold must also be able to measure very high accelerations.

[0043] According to one embodiment, the acceleration measurement device, and in particular the at least one second acceleration sensor, can also be used to determine the distance—for example, by integrating the measurement signal—by which the threshold moves downwards or upwards under load, i.e., the maximum deflection during the load-induced vibration oscillations. This deflection can be used as a parameter for the condition of the ballast, which can be used to determine whether the ballast needs to be filled.

[0044] The use of an acceleration sensor connected to the sleeper also has the advantage that it can be used to detect the presence of a train. Alternatively, the detection of train presence and the triggering of the measurement can also be achieved by measuring sound and / or vibrations using acoustic sensors or by remote control. Alternatively, it can also be achieved in a conventional manner via dedicated entry and exit contacts located in the track bed in front of and behind the device for detecting stuck brakes and / or hot box axles. The detection of train presence serves to start and stop the measurement process.

[0045] Providing first and second acceleration sensors in a device for detecting stuck brakes and / or hot box axles is also advantageous regardless of the mounting of the at least one housing on the upper side of the sleeper. Thus, a system comprising at least one sleeper for supporting rails and a device for detecting stuck brakes and / or hot box axles in rail vehicles is advantageous, wherein the device has at least one housing connectable to a sleeper, wherein at least one infrared temperature sensor and an evaluation unit connected to the at least one infrared temperature sensor for evaluating sensor data are provided in the at least one housing. Furthermore, the device comprises a device for measuring acceleration with first acceleration sensors in the at least one housing, and at least one second acceleration sensor is connected to the sleeper.The at least one second acceleration sensor is connected to the threshold in such a way that it measures accelerations of the threshold and is thus suitable for determining maximum deflections of the threshold under load. Accordingly, in particular, no damping or, alternatively, only a well-known damping is provided between the second acceleration sensor and the threshold.

[0046] With such a system, a method for monitoring loads on the system can be carried out in which measured values ​​of the first and second acceleration sensors are compared with each other.

[0047] According to one embodiment of the invention, the at least one housing of the device has a housing base contour that is stepped in cross-section and is oriented such that the housing has a ground clearance on its underside on the side closest to the rail, wherein the ground clearance, when the housing is mounted on the sleeper, forms a recess for fastening screws of a rail arranged below the housing base. According to one embodiment, the housing does not protrude significantly beyond the sleeper in a longitudinal direction of the rails, wherein the longitudinal direction of the rails is understood here and below to mean the direction parallel to the rail, i.e. the direction of travel of the rail vehicle.

[0048] According to one embodiment, the system further comprises a reference system for functionally testing the at least one infrared temperature sensor, wherein the reference system has at least one heating element arranged in the housing and capable of controlled heating. In addition, the reference system can also have its own temperature sensor, the measured values ​​of which are compared with those of the infrared temperature sensor. According to one embodiment, at least two heating elements are provided to make the system redundant, as well as at least two temperature sensors. The at least one heating element can be heated in a controlled manner to 400 degrees Celsius, for example, and is thus suitable for testing the functionality of the at least one infrared temperature sensor.

[0049] The system may further comprise at least two devices for detecting locked brakes and / or hot box axles on rail vehicles, which are arranged on the same sleeper or on different solid sleepers, as well as a central storage and processing unit that communicates with the evaluation units of the at least two devices. Furthermore, the system may also comprise separate train presence detection devices, provided these are not part of the devices. All elements of the system can be arranged on solid sleepers or in the track bed, thus eliminating the need for a hollow sleeper to accommodate system components.

[0050] According to an aspect which is not part of the present invention, a method for monitoring wheels, axle boxes and / or brake systems in rail vehicles is specified, comprising at least one infrared temperature measurement on the wheels, axle boxes and / or brake systems and at least one acoustic measurement of the sound signals emanating from the wheels, axle boxes and / or brake systems and / or components of a monitoring device used, wherein an alarm is issued when both the infrared temperature measurement and the acoustic measurement of the sound waves emanating from the wheels, axle boxes and / or braking systems result in a critical value and / or if the acoustic measurement of the sound signals emanating from the components of the monitoring device used results in a critical value.

[0051] According to a further aspect, which is not part of the present invention, a method for monitoring wheels, wheelset bearings and / or braking systems in rail vehicles is specified, comprising at least one infrared temperature measurement on the wheels, wheelset bearings and / or braking systems, wherein an axle damage value SA is determined and compared with a specified limit value, wherein the axle damage value SA is dependent on a measured maximum axle temperature and an axle temperature distribution value and the result of the acoustic measurement.

[0052] The axle temperature is determined by infrared temperature sensors. The axle distribution value can be a measure of the temperature differences occurring on the axle and the spatial distances between them.

[0053] Furthermore, the axle damage value may also depend on the current train speed and / or the outside temperature.

[0054] A determined axle damage value SA can in particular be compared with axle damage values ​​SA,i that were already determined for the rail vehicle at earlier times, in particular on the basis of infrared temperature measurements carried out on previous track sections by devices that were passed on previous track sections.

[0055] According to one aspect of the invention, a method for monitoring the described system comprises an acceleration measurement by at least one first acceleration sensor connected to the at least one housing and an acceleration measurement by at least one second acceleration sensor mechanically connected to a sleeper, for example a second acceleration sensor arranged on an upper side of a sleeper or laterally on a sleeper, for determining a maximum deflection of the sleeper when loaded by a passing rail vehicle, wherein measured values ​​of the first and second acceleration sensors are compared with one another in order to determine a load on the at least one device.

[0056] According to a further aspect, which is not part of the present invention, a method for monitoring wheels, axle boxes and / or brake systems in rail vehicles is specified, comprising at least one infrared temperature measurement on the wheels, axle boxes and / or brake systems and at least one acoustic measurement of the sound signals emanating from the wheels, axle boxes and / or brake systems, wherein an alarm is issued if both the infrared temperature measurement and the acoustic measurement result in a critical value.

[0057] According to this method, the infrared temperature measurement is validated by the acoustic measurement. Since the acoustic measurement allows for the detection of damage well in advance, it is possible to validate a critical value of the infrared temperature measurement by the acoustic measurement, thus increasing the reliability of any alarms issued.

[0058] In addition, by linking infrared temperature measurement and acoustic measurement, a self-learning system can be implemented by documenting acoustic measurement series and, in the event of damage, linking them with infrared temperature measurements on the same component. By using RFID tags on trains or components, it is possible to assign time series of acoustic signals to a component and track their development. This can improve damage prediction, allowing the replacement of damaged components to be planned more accurately and economically.

[0059] According to one aspect of the invention, a method for monitoring track systems with rails for rail vehicles resting on sleepers is specified, comprising at least one acceleration measurement by at least one acceleration sensor mechanically connected to a sleeper, for example arranged on an upper side of a sleeper or laterally on a sleeper, for determining a maximum deflection of the sleeper when loaded by a passing rail vehicle.

[0060] Embodiments of the invention are explained in more detail below with reference to schematic figures. Figure 1 shows a cross-section of a system comprising a sleeper for supporting rails with a device according to an embodiment of the invention; Figure 2 also shows, in cross-section, the system according to Figure 1with a device mounted in a second mounting position according to an embodiment of the invention; Figure 3 shows a plan view of the system according to the Figures 1 and 2 ; Figure 4 shows elements of a device for detecting a stuck brake and / or a hot box according to an embodiment of the invention; Figure 5 shows a sectional view of a housing of the Figures 1 and 2 shown device and Figure 6 shows a view from below of the housing according to Figure 5 .

[0061] Figure 1 shows a cross-section through a system 1 comprising a sleeper 2 with rails 3 resting thereon for a rail vehicle and with a device 5 for detecting hard brakes and / or hot box axles according to an embodiment of the invention.

[0062] The threshold 2 is a solid threshold, for example, made of concrete, steel, plastic, or wood. A solid threshold is understood here and below to mean a threshold that, if it has cavities inside – for example, due to production reasons – but, unlike a hollow measuring threshold, does not have any cavities intended to accommodate the measuring technology of the device 5.

[0063] On the sleeper 2, rails 3 are laid at right angles to the sleeper 2 and are fastened to the sleeper 2 by means of fastening screws 11.

[0064] The device 5 for detecting stuck brakes and / or hot box axles is arranged on the upper side 20 of the sleeper 2 by means of a connecting piece 4. In the embodiment shown, the connecting piece 4 is designed as a covering for the sleeper 2, which almost completely covers its upper side 20. The connecting piece 4 is attached to the sleeper 2, for example, by clamping, gluing, or screwing.

[0065] In the embodiment shown, four housings 6, 6' are arranged on the connecting piece 4. The housings 6, 6' can, in particular, be connected to the connecting piece 4 via a damping system (not shown in detail). Infrared temperature sensors 7 and associated evaluation units 8 are arranged in the housings 6, 6'. In addition, further sensors can be provided in the housings 6, 6'. For example, it can be provided to continuously check the connecting lines between the infrared temperature sensors 7 and the evaluation units 8 for damage.

[0066] The externally arranged housings 6 house infrared temperature sensors 7 for measuring the temperature on the wheel sets of a rail vehicle. In this case, the target whose temperature is to be measured lies vertically above a window 9 in the housing 6 that is permeable to infrared radiation, so that radiation incident in the direction of arrow 10, possibly deflected within the housing 6 by means of a mirror (not shown), is received by the temperature sensor 7.

[0067] Infrared temperature sensors 7 are provided in the housings 6' for measuring the temperatures at the rail vehicle's brakes. Such sensors typically do not measure vertically, but rather diagonally upwards. The housings 6' also have correspondingly transparent windows for this purpose, although these are not shown in the figures.

[0068] All housings 6, 6' of the device 5 are arranged on the upper side 20 of the sleeper 2, specifically by means of the connecting piece 4. No elements of the device 5 protrude into the interior of the sleeper 2. Thus, the sleeper is not modified compared to adjacent sleepers.

[0069] The housings 6, 6' do not protrude beyond the top edge of the rail (SOK). Their overall height h is therefore smaller than the difference between the top edge of the rail (SOK) and the top surface 20 of sleeper 2.

[0070] Figure 2 shows the device 5 in a second mounting position. This differs from the one in Figure 1 shown position in that the housings 6 are moved closer to the rails 3. Such a mounting position is advantageous when the target of the temperature measurement is closer to the rails 3.

[0071] In the embodiment shown, the window 9 is arranged almost above the fastening screws 11 of the rails 3. Such a position of the housing 6 is only possible because the housing base contour of the housing 6 has a step, so that in the assembled state, a recess 12 is formed below the window 9, into which the fastening screws 11 protrude in the second assembly position.

[0072] The device 5 can be mounted in the second mounting position if the rail vehicles running on the line have wheel sizes that require temperature measurement closer to the rails 3.

[0073] Figure 3 shows a plan view of a sleeper 2 with housings 6, 6' of the device 5 arranged thereon. The connecting piece 4 has been shown in Figure 3Not shown. The housings 6, 6' have a dimension b in the longitudinal direction of the rails that is smaller than the width B of the sleeper 2. In particular, b is at most 310 mm, especially at most 300 mm, or even less than 290 mm. Thus, in this embodiment, the housings 6, 6' do not protrude beyond the sleeper 2 with their base area A and are not in the way during a tamping process of the gravel bed. A base area A projecting laterally up to 1 cm or up to 2 cm beyond the sleeper would also be possible for most applications.

[0074] Figure 4shows a section of a device 5 according to an embodiment of the invention. The illustrated housing 6, 6' is connected to the connecting piece 4 and thus to the sleeper 2 by means of a schematically shown damping system 13. Vibrations of the sleeper 2 are thus transmitted to the housing 6, 6' only in a damped manner. A first acceleration sensor 14 is arranged in the housing 6, 6', which measures accelerations of the housing 6, 6'. The acceleration sensor 14 can also be connected to the evaluation unit 8 for evaluating its measured data.

[0075] The acceleration sensor 14 can be used to detect the presence of a train to initiate and terminate a measurement phase of the device 5. However, it can also be used to monitor the state of the system 1, as described below.

[0076] Outside the housing 6, 6', a second acceleration sensor 15 is connected to the threshold 2. In the embodiment shown, the connecting piece 4 is designed as a covering for the threshold 2, which is why the second acceleration sensor 15 is arranged on the connecting piece 4. However, the second acceleration sensor 15 can also be connected directly to the threshold 2. The second acceleration sensor 15 measures accelerations of the threshold 2. To read the measurement data from the second acceleration sensor 15, either a separate evaluation unit is provided or the reading is carried out by the evaluation unit 8 in the housing 6, 6'.

[0077] The acceleration sensors 14, 15 are suitable for monitoring the condition of the device 5, the ballast, and for detecting flat spots on the wheels of a passing rail vehicle. For this purpose, measured values ​​from the acceleration sensors 14, 15, in particular measured values ​​recorded at the same time, are compared. If the measured values ​​of the first acceleration sensor 14 are comparable to the measured values ​​of the second acceleration sensor 15, the damping system 13 may not be functioning properly. If the second acceleration sensor 15 detects accelerations only on some wheels of the rail vehicle and the signal has a significant curve, a flat spot on the rail vehicle can be suspected. If the second acceleration sensor 15 detects accelerations on all wheels at a frequency corresponding to the passing of the wheels, the ballast may be poorly packed.

[0078] Furthermore, an acoustic sensor system 19 is arranged in the housing 6, 6', which allows the measurement of sound signals from wheels, wheelset bearings or brakes.

[0079] In addition, inclination sensors and / or sensors for positioning by means of a satellite navigation system, which are not shown in the figures, can be provided in the housings 6, 6'.

[0080] Figure 5shows a sectional view of the housing 6 of the device 5. The housing 6 has a first housing section 16 with a height h 1 and a second housing section 17 with a height h 2 . Here, h 2 < h 1 . The reduced height of the second housing section 17, which is close to the rail in the assembled state, is achieved by the step-shaped housing base 18, so that a recess 12 is formed under the second housing section 17 in the assembled state of the housing 6. In an embodiment not shown, the step can also be less abrupt and resemble a ramp. Even with such a housing base contour, a recess 12 can be achieved under the housing base 18 of the second housing section 17 and such a housing base contour is also referred to as step-shaped. In the embodiment shown, the ratio of the heights h 2 / h 1 = 0.7.

[0081] Figure 6shows a view from below of the housing base 18 of the housing 6. This has a total base area A, which is rectangular in the embodiment shown, but can also deviate from a rectangle. The base area of ​​the first housing section 16 is A 1 , and that of the second housing section 17 is A 2 . A 2 is less than half, but more than one-eighth of A, so that 0.125 A ≤ A 2 ≤ 0.5 A. List of reference symbols

[0082] 1System 2Threshold 3Rail 4Connecting piece 5Device 6, 6'Housing 7Infrared temperature sensor 8Evaluation unit 9Window 10Arrow 11Fastening screw 12Recess 13Damping system 14First acceleration sensor 15Second acceleration sensor 16First housing section 17Second housing section 18Housing base 19Acoustic sensor system 20Top SOKRail top edge ABase area A 1 Base area A 2 Base area BWidth bDimension h 1 , h 2 Height

Claims

1. System (1) with at least one solid sleeper (2) for supporting rails (3) for rail vehicles and at least one device (5) for locating seized brakes and / or hot box in rail vehicles, wherein the device (5) is mounted on an upper side (20) of the sleeper (2), with a housing (6, 6') mounted on an upper side (20) of the solid sleeper (2) and below a rail upper edge, wherein the following is arranged in the housing (6, 6'): - at least one infrared temperature sensor (7); - an evaluation unit (8) connected to the at least one infrared temperature sensor (7) for the purpose of evaluating sensor data, wherein the housing (6, 6') has a base surface A facing the upper side (20) of the sleeper (2), which base surface does not project laterally substantially beyond the sleeper (2), wherein the housing, on its underside, has a ground clearance on a side close to the rail.

2. System (1) according to claim 1, wherein an overall height h of the housing (6, 6') does not exceed 159 mm, in particular 140 mm.

3. System (1) according to claim 1 or 2, further comprising an apparatus (14) connected to the housing (6, 6') for the purpose of measuring acceleration.

4. System (1) according to any one of claims 1 to 3, wherein the housing (6, 6') has a housing base contour which is step-shaped in cross-section and is oriented in such a way that the housing (6, 6') has, on its underside, the ground clearance on its side close to the rail.

5. System (1) according to claim 4, wherein the housing (6, 6') has at least one window (9) for the entry of infrared radiation, wherein the window (9) is arranged on the side of the housing (6, 6') close to the rail with the ground clearance.

6. System (1) according to any one of claims 1 to 5, wherein an acoustic sensor unit (19) for receiving sound signals is arranged in the housing (6, 6').

7. System (1) according to any one of claims 1 to 6, wherein the housing (6, 6') of the device (5) is mounted on the sleeper (2) by means of a connecting piece (4).

8. System (1) according to any one of claims 1 to 7, further comprising an apparatus for measuring acceleration, comprising at least one first acceleration sensor (14) connected to the housing (6, 6') and at least one second acceleration sensor (15) connected to the sleeper (2).

9. System according to any one of claims 1 to 8, further comprising at least one damping device arranged between the sleeper (2) and the housing.

10. System (1) according to any one of claims 1 to 9, further comprising a reference system for checking the function of the at least one infrared temperature sensor (7), wherein the reference system has at least one heating element that is arranged in the housing (6, 6') and can be heated in a controlled manner.

11. System according to any one of claims 1 to 10, comprising - at least two devices (5) for locating seized brakes and / or hot box in rail vehicles, which devices are arranged on the same sleeper or different solid sleepers, and - a central memory and processing unit that is in communication with the evaluation units (8) of the at least two devices (5).

12. Method for monitoring a system according to any one of claims 1 to 11, comprising an acceleration measurement by at least one first acceleration sensor connected to the housing, and an acceleration measurement by at least one second acceleration sensor (15) mechanically connected to a sleeper (2) in order to determine a maximum deflection of the sleeper (2) when subjected to a load caused by a rail vehicle passing over. wherein measured values of the first and second acceleration sensors are compared with each other to ascertain a load on the at least one device (5).