WO2009124775A1

WO2009124775A1 - Device and method for the non-destructive monitoring of the operating state of components made of elastomers

Info

Publication number: WO2009124775A1
Application number: PCT/EP2009/002660
Authority: WO
Inventors: Klaus-Gerhard Scholz; Klaus Zengerle; Christoph Gund; Ralf Heinrich
Original assignee: Klaus-Gerhard Scholz; Klaus Zengerle; Christoph Gund; Ralf Heinrich
Priority date: 2008-04-10
Filing date: 2009-04-09
Publication date: 2009-10-15
Also published as: DE102008018238A1; WO2009124775A4

Abstract

The invention relates to a device for the non-destructive detection of an operating state of elastic components (9), particularly conveyor strips, conveyor belts, or straps having an elastic component (9), which has a band-shaped design and comprises at least one first measuring region (3) and at least one second measuring region (1) in a circumferential conveyor direction, wherein elastomer encoders (8, 8’) are embedded in the measuring regions (1, 3) of the elastic component, further having a sensor station (15) by means of which magnetic fields originating from the elastomer encoders (8, 8') can be detected when passing the sensor station (15) and converted into output signals, and a processor unit (16), which receives signals transmitted by the sensor unit (15), processes the same into expansion data, thus determining a first expansion of the elastomer encoder (8) located in a first measuring region, and a second expansion of the elastomer encoders (8') located in a second measuring region of the elastic component.

Description

Apparatus and method for non-destructive monitoring of the operating state of components made of elastomers

The invention relates to a device and a method for non-destructive in-situ monitoring of the operating condition of components made of plastics, in particular elastomeric materials (rubber), wherein the components may be preferably designed as quasi-endless belts, straps or belts and perform various engineering functions (eg power transmission, transport of bulk materials, etc.). Also conceivable are elastomeric components which are exposed during their use of a thrust, bending, tensile and / or compressive load, which cause a deformation of the components.

Due to their macromolecular structure (high polymers) as well as a wide-meshed cross-linking of their molecular chains, elastomers have a very specific stress / deformation mechanism, which differs from the metallic materials. They show, for example, thermodynamically entropy-elastic behavior, ie that with a deformation under elongation of the clogged chain molecules, the statistically probable arrangement state of these decreases, but a higher order state is reached (unlikely state with decreasing entropy). After deformation, the macromolecules endeavor to regain the initial state of ideal random disorder with maximum entropy. Polymer materials such as elastomers are viscoelastic substances, ie the deformation process is characterized by both elastic and viscous deformations. In the case of purely elastic deformation, the stored energy is released again after discharge, whereas viscous deformations cause a transformation of the deformation energy into heat. These viscous components cause a strong time, temperature, frequency and amplitude dependence of the material data characterizing the deformation.

Depending on the load on the components, these dependencies become apparent in different material effects. Elastomers exhibit under defined loads, whether static, quasi-static or dynamic, phenomena of decrease in stress at constant strain (relaxation) or strain increase at constant stress (creep or creep; H. that with repeated deformation an ever greater way is to be completed in order to achieve the same force. Djiiamic stresses are also noticeable in voltage softening or frequency- and / or amplitude-dependent module deviations. These special laws must be observed if the operating behavior of elastomeric components is to be monitored under practical conditions.

On the other hand, this characteristic material behavior also offers the possibility of recording deviations of the typical stress / deformation behavior for each component and of comparing normal states with deviating states. The definition of the deviation or the achievement of a so-called damage limit presupposes the knowledge of the process under the operating conditions as material and component-appropriate, ie normal running process. In doing so, both continuum-mechanical and primarily fracture-mechanical laws must be observed. Establishing a fatigue life or operating life presupposes many years of operating experience as well as specialist know-how of both the component supplier and the plant operator, and is the responsibility of the technical staff, eg a belt conveyor, which is entrusted with operation, support, maintenance and servicing , Belt conveyors are essential technical aids for the extraction and transport of bulk materials. They are used, inter alia, in the coal, ore and mineral industries and find both in the underground mine as well as in open-pit mining over days an ever-increasing use. In addition to the design of the conveyor systems and their main machine elements such as drives, clutches, brakes, carrying drive, deflection, tension and buckling rollers or drums belonging to the intake of bulk materials conveyor belt is one of the system components, in the particular interest of all maintenance efforts because they are in direct contact with the often highly abrasive bulk material and thus are subject to special wear.

Depending on conveyor requirements, conveyor belts are used as steel cable, textile or aramid fiber conveyor belts. For the purpose of reinforcing the elastomeric material component with the objective of ensuring and maintaining highest material strength values and fulfilling maximized operational requirements with the longest possible service life, these are provided with steel cables, textiles or fibers in such a way that they withstand the highest loads in the main loading (transport) direction are able to. Conveyor belts are system-specific designed so that they can complete an endless circulation along the projected conveyor or transport route. The endless closure is realized by connecting two end pieces by means of special connection methods. This technique is also used to partially renew the conveyor belt by replacing worn sections with new parts or regenerated belt segments.

In this case, since the direct connection of the reinforcing materials is broken or weakened, this connecting section deserves special attention in operational fatigue inspections. By special overlapping techniques of the reinforcing elements is achieved that the transmission or belt force can be introduced into the other element to be connected, wherein the interposed elastomeric material is subjected to shear. Thus, the long-term stress-strain behavior of the elastomer layers involved is decisive for achieving a high fatigue strength or service life of the conveyor belts. This is also the case if damage to the reinforcing layers (crack, breakdown, breakage) has the effect of being canceled or restricted and the elastomeric layers are exposed to increased stresses. It is not surprising that there have been many attempts in the past, through a variety of monitoring techniques, the failure of the conveyor belt, but in particular the connection as one of the critical component regions predetermine and thus a major accident or plant downtime with far-reaching negative in terms of economics and business To avoid consequences. In addition to the usually subjectively influenceable manual controls on said conveyor systems, which are not permanently guaranteed for various business reasons, in particular technical solutions have prevailed that use more and more new findings in electronics, sensor technology and data processing. It is advantageous that as a result of the tape observations the possibility has opened up to statistically record the typical damage patterns and phenomena and present them in the form of a causal cause-and-effect relationship. A distinction must be made between damages that are caused by possible material or manufacturing errors a priori conditionally or process-dependent or occur a posteriori as a result of overloads.

Due to the process cover plate damage (punctures, cracks) of the conveyor belt, especially on the support and running side by wear (impact wear), abrasion (abrasion wear), friction (adhesive wear), erosion (erosional wear) and fatigue (fatigue wear) and their Combinations (combined wear) as reduction or caviar-like disturbances. This also applies to so-called edge damage. Removal of material layers often has its cause in material and production or assembly-related processes and always lead to weakening of the belt material and / or the connection. This relates primarily to a weakening of the bond between newly applied (joining) material and the reinforcing material (carcass) associated with elastomers. These damages are expressed in the area of highest stress concentration, i. h thus directly on either side before or directly in the contact zone, which is formed of compound and base material or in the zones where the rope ends of both sides of the connection are unbounded.

The burden of the actual connection length is due to the

Shear stress transmission of the coupling elastomer with the

Tensile beams relatively manageable and more stable compared to the contact zone, but without reaching the strength level of the original Gurtmaterials.

The publication US 4,020,945 describes a method in which a change in length between the markings can be detected by means of sensory detection by applying markings at the beginning and at the end of the connection. Permanent pulses triggered by permanent magnets define a "critical strain" as the beginning of the damage.

Likewise using the RFID (transponder) technology, DE 196 03 578 shows a monitoring method which works on the principle that transponders, integrated into integrated circuits, are no longer capable of being transported by an increased unacceptable load in a conveyor belt to send signals to the transmitting and receiving stations arranged on the conveyor system.

Magnetic inductive tests on conveyor belts provide insight into the interior of a suspected damaged section. An interpretation is difficult and must be supported by an additional X-ray technique.

The use of high-energy (X-ray) radiation is mentioned in DE 10 2004 061 367. After irradiation of the belt evaluates Process computer from the result obtained. The assignment to the damaged area is made with the help of markings (magnets, encoders).

A similar solution can be found in DE 2004 00 1899 (WO 2005/023688). With the help of opto-electronic systems and subsequent evaluation by a process computer, it is possible to monitor the belt surface over a large area. The conveyor belt and thus the connection is subdivided into finite sections, which can be delimited by start markings in the form of encoders coupled to a process computer.

In the belt or the connection incorporated so-called conductor loops according to US 4854446 are mentioned, which inductively coupled in the injury due to high Gurtbeanspruchung cause a change in the measurement signal.

From the operating experience presented, it can be concluded that further developments in the technology of the changes in length of the connections determined by means of magnetic measuring marks should be tackled with regard to reliability and reduced susceptibility. The damage criterion is an increase in the connection length (7 m long) of 1% o, since this already corresponds to a doubling of the scattering range of 3 mm.

Recent studies on the determination and calculation of component strength and lifetime of elastomeric materials as well as refinement of the test technique using Tear Fatigue Analyzer (TFA) tests involving continuum and fracture mechanics material approaches allow the failure behavior of elastomers to describe more precisely and to better evaluate the progress of damage. In stress-determined processes such as in a belt conveyor, the deformation-related characteristic values are of interest. Thereafter, it is necessary to a clearer determination or metrologically reliable detection of a

Material damage beginning to arrive in a component, in particular to detect the zones of critical deformations and voltages high resolution to define different areas of the damage can.

All previously known methods and methods have the disadvantage that they do not precisely detect the sometimes very narrow zones of Bruchimitiierung and crack growth on the component as the starting point of failure and thus provide relatively unreliable values for the life expectancy. However, these are required to make a decision that at least some of the component in a particular stage of failure is to be repaired or replaced. Another difficulty is to be seen in the fact that the assignment to the damage location, i. H. the identification is realized with two different systems, which includes additional source of error.

The object of the invention is therefore to specify a method, a device and a locally high-resolution measuring system for the nondestructive detection of the operating state of elastic components, in particular conveyor belts, conveyor belts or belts, the statically and / or dynamically loaded components in situ safely and can reliably monitor.

In addition, the measuring system should be able to accurately determine the measuring location as an integrated measuring task without separate To identify or locate additional measuring devices and due to the special arrangement of the measuring points opens up an additional possibility to take over a number of other monitoring functions (eg belt misalignment, wear). Furthermore, an evaluation method is to be provided, by means of which it is possible to reliably detect critical component states.

The object is solved by the independent claims. The dependent claims relate to advantageous developments of the invention.

The device for nondestructive detection of an operating state of elastic components, in particular conveyor belts, conveyor belts or belts may have at least one elastic component which has a band-shaped configuration and has at least one first measuring range and / or at least one second measuring range in a band-circumferential direction of the elastic member elastomerecoder can be embedded. Furthermore, a sensor station can be provided, with which magnetic fields emanating from the elastomer encoders can be detected as they pass through the sensor station and can be converted into output signals. Furthermore, a process unit can be provided which receives signals transmitted by the sensor unit, processes them into strain data, and thus a first elongation of the elastomere encoders which are located in a first measuring range and / or a second elongation of the elastomere encoders which are located in a second measuring range of the elastic component. In this case, the process unit can determine a first expansion difference between the first expansion and a first predetermined expansion value and / or determine a second expansion difference between the first expansion and the second expansion and / or based on the determined expansion difference determine an operating condition of the elastic member. This results in the advantage that for detecting the operating state and thus for monitoring the wear, the belt conveyor does not have to be stopped or dismantled. Thus, the conveyor can be kept permanently in operation whereby the service life is reduced. In addition, the number of components is reduced since the same encoders are used to detect the conveyor belt speed and belt wear. The reference measurement in the second measuring ranges can prevent incorrect measurements due to environmental influences such as temperature, pressure and humidity.

In this case, the first predetermined expansion value can correspond to a maximum permissible elongation of the component to be examined. This value can be stored in a memory or a database. The database may be in the form of a table with strain values that vary depending on the material, age, environmental conditions of the component. According to these criteria, a first strain value from the table is predetermined. The first and the second strain difference are compared with a first and second value, respectively. This first or second value corresponds to a maximum permissible expansion difference of the component to be examined. These values can be stored in a memory or a database. The database may have a table of strain differential values, which may vary depending on the material, age, environmental conditions of the component. According to these criteria, a first or second value from the table is predetermined.

Furthermore, the first measuring area may be an area in which two ends of the elastic member are connected to each other. Furthermore, the first measuring range may have a tensile strength that decreases more rapidly over time than the second measuring range. Furthermore, if the determined first strain difference exceeds a first predetermined value or the determined second strain difference exceeds a second predetermined value, the process unit may output at least one predetermined operating condition signal.

Furthermore, the operating state signal may correspond to a current strain state or a strain state in which the first strain difference exceeds the first predetermined value or the second strain difference exceeds the second predetermined value.

Furthermore, the magnetic fields detectable by the sensor station can have alternating polarity, the elongation of the elastic component can be determined simultaneously with the rotational speed of the elastic component, and / or a second, parallel embedded, barcode magnetized elastomeric encoder and at least one additional sensor in the sensor station be, with the additional elastomere encoder a band section can be clearly identified.

Furthermore, the device may have a sensor station with at least two analog sensors with preamplifier and / or a local processor unit.

Furthermore, the device can have a second, parallel embedded, barcode magnetized elastomeric encoder and / or at least one additional, third sensor in the sensor station, wherein a band section is uniquely identifiable with the additional elastomeric encoder.

In this way, the band section to be monitored can be uniquely identified in a particularly simple manner. Furthermore, in the strain measurement, the device can double determine the strain by independent measurements.

Thus, an improvement in redundancy can be achieved.

Furthermore, the elongation can be localized with the device, preferably with a spatial resolution of a pole width of not more than 50 mm.

Furthermore, the elongation can be localized with the device, preferably with a spatial resolution of two pole widths of not more than 100 mm.

Furthermore, the elastomeric encoder can be prepared by adding a filler, wherein the filler may be strontium ferrite (SrFeO) and / or an iron alloy (NdFeB), wherein the elastomeric encoder by adding a filler of 20 to 40 vol.% Strontiumferrit (SrFeO), however, preferably 30 vol.% strontium ferrite (SrFeO), and / or from 5 to 30 vol% iron alloy (NdFeB) modified elastomer mixture can be produced and may be covered by non-magnetic material.

Furthermore, by adding this filler, the mechanical physical properties of the vulcanizate of the elastomeric encoder can only be changed insignificantly.

Furthermore, the elastomere encoder can be present as a band and / or plate with a thickness of 1 mm to 5 mm and dimensions preferably of 1000 mm length and 100 mm width and / or composable from such bands and / or plates.

Furthermore, the Elastomerencoder both before installation in the elastic member (a conveyor) and after the Installation by means of Impulsmagnetisiertechnik, using specially modified elastomer mixtures, be magnetized.

Furthermore, the Polbreiten or Polabständen the Elastomerencoders of 20mm to 50mm, but preferably 40mm amount.

Furthermore, the device may be characterized in that the orientation of the Elastomercoder deviates at most 5 ° from the conveying direction or direction of travel of the conveyor.

Furthermore, the elastomere encoder can be fastened in the conveyor device with the joining methods developed for elastomers.

Furthermore, a width of the Elastomerencoders can be adapted to a measuring width of the sensor so that at extreme belt misalignment of the conveyor, the sensor no longer reaches the measuring range of Elastomerencoders and thus an error message can be triggered.

Furthermore, the Elastomerecoder be coded so that its installation point can be identified.

Furthermore, a device for conveying goods may consist of at least one elastic component, which may have a band-like shape and may have at least one first measuring range and / or at least one second measuring range in a band circumferential direction. In this case, elastomere encoders can be embedded in the measuring regions of the elastic component. Furthermore, a sensor station can be provided, with the magnetic fields (pulses) emanating from the elastomeric encoder can be detected when passing through the sensor station and can not be converted into output signals. Furthermore, a process unit may be provided, which is provided by the Sensor unit receives signals transmitted, processed into strain data, and thus a first strain of elastomerecoder which are located in a first measuring range and / or a second strain of elastomerecoder which are located in a second measuring range of the elastic member determine. Furthermore, the process unit can determine a first strain difference between the first strain and a first predetermined strain value and / or determine a second strain difference between the first strain and the second strain and / or determine an operating state of the elastic component based on the determined strain difference.

Furthermore, the first measuring area may be an area in which two ends of the elastic member are connected to each other. Furthermore, the first measuring range may have a tensile strength that decreases more rapidly over time than the second measuring range.

Furthermore, if the determined first strain exceeds a first predetermined value or the determined strain difference exceeds a second predetermined value, the processing unit may output at least one predetermined operating condition signal.

Furthermore, the operating state signal may correspond to a current strain state or a strain state in which the strain exceeds the first predetermined value or the strain difference exceeds the second predetermined value.

Furthermore, at least one running side and at least one carrying side can be provided, wherein between the running side and the carrying side elastic elastomer encoders are embedded, which are suitable to output changing magnetic signals. Furthermore, the elastomere encoders can be embedded in a specific layout, which corresponds to the arrangement of sensors of a sensor station.

Furthermore, distributed over the width of the device for conveying goods, at least three elastomere encoders in the transition zones, which may extend into deflection zones of cables or an offset zone of cable ends, and / or are in Seilendabstandszonen.

Furthermore, at least three reference elastomere encoders can each be arranged in the middle and in the right and left edge regions between connections of the device.

Furthermore, the elastomere encoders can be located at a distance from the running side, from the carrying side and / or from the upper and / or lower plane of steel cables, depending on the measuring equipment of the sensor station, depending on their rope diameter.

Furthermore, the Elastomercoder can be anchored in a transition zone with one half of its length in a belt side and with the other half in a connecting side.

Furthermore, the elastomeric encoders may be positioned in a rope end clearance zone so as to cover both ends of the rope.

Furthermore, a sensor station with which magnetic fields emanating from elastomer encoders can be detected as they pass through the sensor station and can not be converted into output signals can be provided. In this case, the elastomere encoders can be embedded in measuring areas of an elastic component which has a band-shaped form. In this case, the elastic member in a band circumferential direction at least one first measuring range and at least one second measuring range aurweisen. Furthermore, a process unit may be provided which receives the signals emitted by the sensor unit, processed into strain data, and thus a first elongation of the elastomere encoders located in a first measurement range and / or a second elongation of the elastomere encoders located in a second measurement range of the elastic component determine. Furthermore, the process unit can determine a first strain difference between the first strain and a first predetermined strain value and / or determine a second strain difference between the first strain and the second strain and / or determine an operating state of the elastic component based on the determined strain difference

Furthermore, the sensor station can be positioned on a belt conveyor system, and depending on the head or rear drive situation, both on the running side of an upper run and the running and carrying side of a lower run, the belt conveyor, can be positioned.

Furthermore, the sensor station depending on the system situation in the vicinity of a belt conveyor drum, a roller system and / or a pressure roller in the form of a support or Anpresstrommel be positioned, their distance from the running side of the conveyor belt is minimal and / or the sensor station rests directly on this.

Furthermore, depending on the plant situation, the sensor station can be mounted on the running side between a bulk material feed point and / or a bulk material transfer or bulk discharge point in the lower or upper strand.

Furthermore, the sensor station can be aligned over the design-related normal transport position of the conveyor so that both equipped with Elastomerencodern edge areas and a central region of the conveyor can be detected.

Furthermore, the sensor station can optionally be traversing movable as a single station, and / or permanently installed as a triple station, each with a single station in the edge regions and a single station in the central region, be arranged.

Furthermore, the sensor station may comprise at least two sensors with a predetermined sensor spacing.

Furthermore, the sensors Hall sensors of ratiometric linear design are.

Furthermore, the device may be characterized in that the sensor station is connected to a process unit. Furthermore, at least one connection can be provided between the sensor station and the process unit, this being implemented via cable and / or wireless.

Furthermore, data can be forwarded to a plant-specific operating data acquisition system with the process unit, it being possible to provide information about possible disruption situations, as a result of which an emergency shutdown of the plant can be carried out with a plant controller.

The invention further relates to a method for nondestructive detection of an operating state of elastic components, in particular of conveying devices and may comprise the following steps: detecting a first elongation of elastomer encoders embedded in a first measuring range of a conveying device, determining a first expansion difference between the first elongation and a first predetermined strain value, and / or detecting a second strain of elastomer encoders embedded in a second measurement range of the conveyor, determining a second strain difference between the first strain and the second strain, determining an operating state of the elastic member based on the determined strain difference, Output of at least one operating state signal when the determined first strain difference exceeds a first predetermined value and / or when the determined second strain difference is a second vorb value exceeds.

In a further step, if the determined first strain exceeds a first predetermined value or the determined strain difference exceeds a second predetermined value, at least one predetermined operating condition signal may be output. The operating state signal may correspond to a current strain state and / or a strain state in which the strain exceeds the first predetermined value and / or the strain differential exceeds the second predetermined value.

Furthermore, by the method, the elongation of the components and the conveying speed can be detected simultaneously.

Furthermore, a Elastomerencoders can be used for measuring the elongation of elastic components, wherein the elongation of an elastic member based on an elongation of at least one Elastomerencoders can be detected.

Furthermore, the elongation of the elastic member can be detected simultaneously with the rotational speed of the elastic member.

Furthermore, the elastomeric encoder can be prepared by adding a filler, wherein the filler is strontium ferrite (SrFeO) and / or an iron alloy (NdFeB), wherein the elastomeric encoder by adding a filler of 20 to 40 vol.% Strontiumferrit (SrFeO), preferred However, 30 vol.% Strontium ferrite (SrFeO), and / or 5 to 30 vol% iron alloy (NdFeB) modified elastomer mixture is produced and is covered by non-magnetic material.

Furthermore, the elastomeric encoder can be present as a band or plate with a thickness of 1 mm to 5 mm and dimensions of preferably 1000 mm in length and 10 to 100 mm in width and / or be composed of such bands or plates. Furthermore, the Elastomerecoder can be magnetized before installation as well as after its installation by means of pulse magnetization.

Furthermore, the pole widths or pole spacings of the elastomer encoder may preferably be from 100% to 400% of the effective sensor spacing.

Furthermore, the orientation of the elastomeric encoder can deviate a maximum of 5 ° from the conveying device or driving direction of the conveying device.

Furthermore, a width of the elastomer encoder can be adapted to a measuring width of the sensor system so that the sensor system no longer reaches the measuring range of the elastomer encoder in the event of an extreme belt slippage of the conveying device and thus an error message can be triggered.

Furthermore, the Elastomerecoder be coded so that its installation point is identifiable.

Furthermore, the component to be monitored (conveying device), for example a conveyor belt made of reinforced plastics, in particular elastomers, which is provided with elastomer encoders of magnetized elastomers (magneto elastomer), and / or in a Magnetcoderanordnung during its functional use of a sensor system (sensor station, sensor ) is passed, whereby permanently the deformation state of the component at particularly stress and deformation exposed areas (eg transition zone, transitional zone, Seilendenabstandszone) is measured and metrologically evaluated by means of a process computer, which is connected to the Betriebsdatenerfassungsungs- or control system of the system.

In the following the invention will be explained with reference to drawings showing only exemplary embodiments.

It is shown schematically and not by way of limitation:

FIG. 1 shows the laying scheme of a 3-stage steel cord conveyor connection with magnetic encoders and comparison measuring points positioned therein;

FIG. 2 shows a cross section through a transition zone of one side of a belt connection with transverse reinforcements and steel cable and the positioning of the magnetic encoder to the running cords of the conveying device and carrying side of the conveying device,

FIG. 3 shows an arrangement of the measuring sensor system on the belt conveyor system above the conveyor belt provided with magnetic encoders,

FIG. 4A shows an arrangement of the sensors in a sensor station with respect to the elastomer encoder and the coding of the encoder in the north pole and south pole.

FIG. 4B: sensor signals which are sent from the sensor station to the process unit;

Figure 5: the increase in strain as a function of the load cycle number at a predetermined load (load duration), and Figure 6: a belt conveyor.

According to the description of the invention and the task, the operating principle (method) of the monitoring device is to determine the component deformation in zones of highest operating stress in order to determine its fatigue behavior (fatigue wear).

According to the invention, the critical deformation is to be determined as such a change in length which, in contrast to the component-specific intrinsic extension, exceeds a certain amount under the operating load. Values of 2% to 4% depending on the belt version are mentioned in the literature. The values measured in the connection in the transition area between belt side and connection side Fig. 2, area 4 and Fig. 1 area 4 or 4 'may assume higher values, so that an accurate strain measurement in the range between 4% and 8% and beyond is.

Using transponders in conjunction with strain gages would require the use of strain-gaging systems. However, the determination of discrete maximum elongation values is not only promising for the determination of a damage limit, but only the determination of the functional dependence of the strain increase ΔD on the loading time allows a general assessment of the fatigue behavior with high certainty.

Since the application of the strain gauges encounters certain limits, it is inventively provided with a time measurement To detect a sensor system, the fields of a special Magnetcoders. This is designed so that it reproduces the component elongation to 100%. Therefore, so-called magnetic elastomers are used, which consist of a magnetizable elastomer mixture. These elastomer blends contain a certain amount of ferritic particles (filler) which ideally align with the mixing and processing process typical of elastomer production. With the aid of a special magnetizing device, it is now possible to magnetically encode this mixture thus prepared in the form of precisely positioned north / south poles with defined pole widths and spacings. This magnetic elastomer can be regarded as elastomerscoder 8 or 8 'in the form of a stretchable magnetic encoder about 1-3 mm thick.

The possible variants of the introduction of the encoder are shown in Fig. 1. The elastic member is shown in the form of a conveyor belt 9. The two end pieces of a connection 1 and 2 as well as the connection length 3 opened for the connection, ie freed from waste rubber, can be seen. The positioning of the elastomere encoders 8 or 8 'takes place according to a predetermined scheme both for reference measurement in at least one second measuring range (reference ranges). on the two belt ends to be connected (in the belt side 1, see Fig. 2) and for the strain measurement in at least one measuring range (range of critical elongation) in the connection itself (connecting side 3, see Fig. 2). In this case, the elastomere encoders 8 'between the connections are preferably embedded in the lateral edge regions as well as in the middle of the conveyor belt 9. For reference measurements, moreover, elastomere encoders 8 can optionally be accommodated in the first measuring range (the zones of critical loads), so-called transition zones 4, 4 ', 5, 6 and 7. The introduction is usefully possible in connection, repair, regeneration in the workshop as well as on site with the known methods of joining or joining technology for elastomers possible. The width of the Elastomerecoder 8, 8 'is to be chosen so that in normal running inaccuracies of the conveyor belt 9, a measurement is still feasible.

FIG. 2 shows a cross section through a contact zone of the belt side 1 and the connection side 3 of a cross-armored steel cord conveyor belt 9 with the possible height arrangement of the elastomere encoder 8 in relation to the belt running side 14 and belt support side 13.

The distance between the running side 14 and the possible transverse reinforcements 17 and the steel cable 18 of the conveyor belt 9 depends both on magnetic sensor (up to 24 mm) and wear criteria. It can be seen immediately that if the elastomer layer of the running side 14 should be reduced so far by wear that the encoder 8 are exposed to abrasion, they can send out any further signals to the sensor station 15 and thus an additional wear monitoring the running side 14 is given. This arrangement is of course conceivable on the support side 13. An impairment of Elastomerecoder 8 and the sensor station 15 through the transverse reinforcements 17 and steel cables 18 is excluded.

FIG. 3 shows one of the possible arrangements of the sensor system 15 on a belt conveyor system in the vicinity of a drive or deflection drum 10. The conveyor belt 9 doped with elastomer encoders 8 is guided through or via various cleaning systems 19 and fixed by means of a usually arranged buckling drum 11 with a support or Anpresstrommel 12.

The positioning of the sensor 15 is to be matched with the Elastomerencoderbreite 8 and 8 '. Deviations during belt misalignment result in false signals. With the help of this lack of signaling, the belt misalignment can ideally also be monitored. The distance of the sensor 15 to the belt side 14 is to be chosen so that a direct contact or a metrologically still feasible distance is made possible.

The arrow R indicates the direction of rotation of the conveyor belt 9. Of course, the functionality of the detection device is also given in the opposite direction of movement.

The sensor station 15 is connected to a process computer 16 for the purpose of measured value detection and measured value evaluation.

FIG. 4A illustrates the measuring principle of the active magnetic encoder in the form of the described elastic elastomer encoder 8 or 8 '. By arranging two magnetic sensors S 1 and S 2, the magnetic encoder speeds (+/- 1% with a standard deviation of 0.3%) as well as the strains (+/- 1%) can be calculated with high precision in one measurement cycle and with Compare the measurements at a arranged next to the compound or between the compounds reference measuring point 8 '. An encoded elastomere encoder 8, is passed to two sensors Sl and S2, which detect magnetic north south pulses of Elastomerencoders. FIG. 4B schematically shows the measurement signals emanating from the sensor station. The four combinations demonstrate the measuring principle used in the stages:

I) fast, unstretched

II) slow, unstretched

III) slow, stretched and

IV) fast, stretched

Reference measurements between the encoders 8 and 8 'are also possible according to this system. In this case, A corresponds to the signal duration of a reference signal of an encoder 8 ', with which the rotational speed of the conveyor belt can be detected at a position uncritical with respect to the elongation. B corresponds to the duration of a signal from an encoder 8 which is located at a stretch-critical point in a connection point of the conveyor belt. By means of the signals A and B, an adjustment of the rotational speeds can take place and thus the presence of an elongation can be detected.

For the purpose of integration into a computerized

Operating data acquisition system, it is intended to connect the process computer via a bus system with the maintenance portal and as part of the overall system monitoring data for evaluation for the control center for the purpose of possibly necessary, in emergency situations indispensable plant closures to deliver. In conjunction with other measured variables, this operating case can be controlled redundantly in such a way that faulty circuits can be excluded by possible measurement disturbances. Via a separate coding of the elastomere encoder 8 it is achieved that an exact positioning of the damage can be detected. If required for further additional identification and information messages, it is quite possible to provide the use of transponders.

Of course, elastomere encoder 8 can also be introduced into the intermediate layers of textile conveyor belts in the case of single-stage or multi-stage connections or applied to the transition zones 4, 4 'between the two layer ends. This also applies to any other type of conveyor belts and conveyor belts 9, drive belts or the like.

As already stated in the description and the task, it may be useful to make the determination of a damage limit on the basis of reference strain data such as a measured relationship strain increase = f (load cycle number, load duration), wherein the strains measured at the encoders 8 and with the strain in connection remote encoder 8 'is compared.

In Figure 5, such a relationship is exemplified when testing an elastomeric component. The graphs in the left half show component fatigue based on strain versus load cycles, and the graphs in the right half show stress with a defined force over a cycle time. It can be clearly seen that at a defined load (in the example 1.0 kN) of a material sample after certain load periods A, B, C, and D (sectors I, II, III and IV) a typical slope of the function in the individual characteristic sections. The increase in the slope of the function indicates a steadily increasing component fatigue, the finally at point D leads to breakage of the sample. The four areas are therefore criteria to be used for the assessment of the damage.

While in zone I an absolute uncritical increase in strain (flow) can be observed, starting from point A in zone II an uncritical partial component damage already begins, which noticeably intensifies from point B in zone III and can already be described as critical. Upon reaching zone IV at point C, an already significant failure of the component occurs, which at point D leads to the failure of the operability.

Of course, reference curves of this kind can also be created with steel rope harness specimens in which appropriate graphs are recorded using dynamic testing machines (hydropulser). It is crucial that the test reflects the practical conditions almost ideally.

In a higher tribological test category (worksheet no. 7 of the Society of Tribology (GfT) "Tribology") carried out test bench tests according to DIN 22110, T3 using the inventive arrangement of elastomer encoders allow in addition to the laboratory experiments in a tribological test chain the preparation of reference curves, the considerably facilitate the determination of the damage situation on a belt conveyor.

FIG. 6 shows the diagram of a belt conveyor 20 with alternative possibilities for positioning the sensor system 15 to its drives. Depending on the design and arrangement of the drive situations, these are referred to as head or tail drives (depending on the bulk material conveying direction) according to DIN 22101, wherein rear drives usually the bulk material feeding station at the beginning and Head drives the bulk material discharge station at the end of the conveying path are assigned.

The above lying conveying zone of the belt conveyor is referred to as upper run, the lower bulk-free zone as Untertrum. For the purpose of safe bulk transport, the upper zone is usually troughed, d. h at the edges each bent by a certain angle upwards.

The positioning of the sensor 15 has to adapt to these conditions so that both the overload of bulk material largely avoided as well as the zones highest Gurtübertragungskräfte, depending on the type of drive metrologically be achieved safely.

All ranges of values given in the present description also include the marginal values. The features mentioned above and exemplified by the present invention may be combined, in part or in whole, as desired, to form further embodiments adapted to corresponding applications of the invention. Insofar as such embodiments result for a person skilled in the art from the abovementioned exemplary embodiments, these are to be regarded as implicitly disclosed with the abovementioned exemplary embodiments.

Claims

claims

1. A device for non-destructive detection of a

Operating state of elastic components (9), in particular conveyor belts, conveyor belts or belts comprising: at least one elastic component (9) which has a band-shaped configuration and has at least one first measuring region (3) and at least one second measuring region (1) in a belt circumferential direction, wherein elastomeric encoders (8, 8 ^* ) are embedded in the measuring regions (1, 3) of the elastic component (9), at least one sensor station (15) with the magnetic fields emanating from the elastomer encoders (8, 8) as they pass through the sensor station ( 15) are detectable and unchangeable in output signals, and at least one process unit (16) receiving signals emitted by the sensor unit (15) is processed into strain data, and thus a first elongation of the elastomere encoders (8) located in a first measurement range , determined, characterized in that the process unit (16) has a first expansion difference between the first elongation and a first vorbe determined elongation value, or a second elongation of the Elastomerecoder (8 *), which are located in a second measuring range of the elastic member, determined and a second expansion difference between the first elongation and the second elongation determined, and based on the determined elongation difference, an operating condition of elastic component determined.

2. Apparatus according to claim 1, wherein the first measuring area (3) is a region in which two ends of the elastic member (9) are connected to each other, wherein when the determined first strain difference exceeds a first predetermined value or the determined second strain difference exceeds a second exceeds the predetermined value, from the process unit (16) at least a predetermined operating state signal is output.

3. Device according to claim 1 or 2, wherein the operating state signal is a current

Strain state or a strain state corresponds, in which the first strain difference exceeds the first predetermined value or the second strain difference exceeds the second predetermined value.

4. The device according to at least one of claims 1 to 3, wherein the detectable with the sensor station (15) magnetic fields have alternating polarity, the elongation of the elastic member (9) can be determined simultaneously with the rotational speed of the elastic member (9), and a second, embedded in parallel, magnetized as a bar code elastomer encoder and at least one additional sensor is provided in the sensor station, wherein the band with the additional Elastomerencoder is clearly identifiable.

5. The device according to at least one of claims 1 to 4, wherein the elongation localized, preferably with a spatial resolution of a pole width, of a maximum of 50 mm, can be determined, particularly preferably with a spatial resolution of two Polbreiten, of a maximum of 100 mm, can be determined.

6. The device according to at least one of claims 1 to 5, wherein the elastomeric encoder (8) can be produced by adding a filler, wherein the filler is strontium ferrite (SrFeO) and / or an iron alloy (NdFeB), wherein the elastomeric encoder (8) by adding a filler of 20 to 40 vol.% Strontium ferrite (SrFeO), but preferably 30 vol.% Strontium ferrite (SrFeO), and / or 5 to 30% by volume iron alloy (NdFeB) modified elastomer mixture is produced and non-magnetic material is covered.

7. The device according to at least one of claims 1 to 6, wherein the elastomere encoder (8) is present as a band or plate with a thickness of lmm to 5mm and dimensions preferably of 1000mm length and 100mm width and / or composed of such bands and / or plates is.

8. The device according to at least one of claims 1 to 7, wherein the Polbreiten or Polabständen the Elastomerencoders (8) from 20mm to 50mm, but preferably 40mm amount.

9. Device according to at least one of claims 1 to 8, wherein the orientation of the elastomeric encoder (8) a maximum of 5 ° from the conveying direction or direction of travel of the elastic member (9) deviates.

10. The device according to at least one of claims 1 to 9, wherein a width of the Elastomerrencoders (8) to a measuring width of the sensor station (15) is adaptable so that at extreme belt misalignment of the elastic member (9), the sensor station (15) the measuring range of Elastomerencoders (8) is no longer reached and thus an error message can be triggered.

11. The device according to at least one of claims 1 to 10, wherein the elastomere encoder (8) is coded so that its installation point is clearly identifiable.

12. Device for conveying goods consisting of an elastic component (9), which has a band-shaped form and in a band circumferential direction at least a first measuring range (3) and at least a second measuring range (1), and in the measuring ranges (1, 3 ) are embedded with at least one sensor station (15), of the elastomeric encoder (8. 8 *) outgoing magnetic fields when passing through the sensor station (15) and unchangeable in output signals, wherein at least one process unit (16) which receives signals emitted by the sensor unit (15) is processed into strain data, and thus a first elongation of the elastomere encoders (8) which are located in a first measuring range, characterized in that the process unit (16 ) determines a first strain difference between the first strain and a first predetermined strain value, or a second strain of the elastomer encoder (8% located in a second measuring range of the elastic member (9) determines and determines a second strain difference between the first strain and the second strain, and based on the determined strain difference one Operating state of the elastic member determined.

13. The apparatus of claim 12 having at least one running side (14), and at least one support side (13), wherein between the running side (14) and the support side (13) stretchable Elastomerencoder (8, 8 ') are embedded, which are suitable changing output magnetic signals, and the first measuring range (3) is an area in which two ends of the elastic member (9) are interconnected.

14. The device according to claim 12 or 13, characterized in that the Elastomerencoder (8, 8 ') are embedded in a certain Legeschema, which corresponds to the arrangement of sensors (Sl, S2) of a sensor station (15).

15. The device according to at least one of claims 12 to

14, characterized in that distributed over the elastic member (9), at least three elastomere encoders (8, 8 *) are in transition zones (4, 4 '), which extend into deflection zones of ropes (5) or an offset zone of cable ends (6) and / or are located in rope end clearance zones (7).

16. The device according to at least one of claims 12 to

15, characterized in that between connections of the device at least three reference elastomerecoder (8 ') respectively in the middle and in the right and left edge regions are arranged.

17. The device according to at least one of claims 12 to

16, characterized in that the elastomere encoder (8) in a transition zone (4) with one half of its length in a Belt side and with the other half anchored in a connecting side.

18 sensor station (15), with the elastomeric encoders (8. 8 ^* ) outgoing magnetic fields when passing the sensor station (15) are detectable and unchangeable in output signals, the Elastomercoder (8, S ') in measuring ranges (1, 3 ) of an elastic component (9), which has a band-shaped form, wherein the elastic component (9) has at least one first measuring region (3) and at least one second measuring region (1) in a belt circumferential direction, wherein a process unit (16), receives the signals emitted by the sensor unit (15), processed into strain data, and thus determines a first elongation of the elastomere encoders (8) located in a first measuring range (3), characterized in that the process unit (16) has a first strain difference determined between the first elongation and a first predetermined elongation value, or a second elongation of the Elastomercoder (8 ⁵ J, which in a second measuring range of the elastisc hen hen a second expansion difference between the first strain and the second strain are determined, and determined based on the determined strain difference an operating condition of the elastic member.

19. Sensor station (15) according to claim 18, characterized in that the sensor station (15) on a belt conveyor (20) can be positioned, and depending on the head or rear drive situation, both on the running side of an upper run and the running and supporting cables of a lower run . the belt conveyor (20) is positionable, or wherein the sensor station (15) depending on the system situation in the vicinity of a belt conveyor drum (10), a roller system (11) and / or a pressure roller in the form of a support or Anpresstrommel (12) can be positioned , Wherein their distance from the running side (14) of the conveyor belt (9) is minimal and / or the sensor station (15) rests directly on this.

20. sensor station (15) according to claim 18 or 19, characterized in that the sensor station (15) either traversing movable as a single station, and / or permanently installed as a triple station, each with a single station in the edge regions and a single station in the central region, can be arranged.

21. Sensor station (15) according to at least one of claims 18 to 20, characterized in that the sensor station (15) comprises at least two sensors (S 1, S2) with a predetermined sensor distance.

22. Sensor station (15) according to at least one of claims 18 to 21, characterized in that the sensors (Sl, S2) are Hall sensors of ratiometric linear design.

23. The device according to at least one of claims 1 to 11 and 18 to 21, wherein the process unit (16) the data to a plant-specific operating data acquisition system can be forwarded, with information on any disturbance situations are available, due to an emergency shutdown of the plant executable with a plant control is.

24. A method for nondestructive detection of an operating state of elastic components (9), in particular of devices according to claim 12, with the steps

Detecting a first elongation of elastomer encoders (8) embedded in a first measuring region (3) of an elastic component (9),

Determining a first strain difference between the first strain and a first predetermined strain value, or detecting a second strain of elastomer encoders (8 *) embedded in a second measurement region (1) of the elastic member (9), and

Determining a second strain difference between the first strain and the second strain, and determining an operating condition of the elastic member based on the determined strain difference, outputting at least one operating condition signal if the determined first strain difference exceeds a first predetermined value, or if the determined second strain differential exceeds a second predetermined value.

25. The method of claim 24, wherein the elongation of the elastic member (9) and the rotational speed of the elastic member (9) are detected simultaneously.

26. Use of a Elastomerecoders (8) for measuring the elongation of elastic components (9), characterized in that the elongation of an elastic member (9) by means of an elongation of at least one Elastomerencoders (8,8 ') is detectable.

27. Use according to claim 26, wherein the elongation of the elastic member (9) simultaneously with the Circulation speed of the elastic member (9) can be detected.

28. Use according to claim 26 or 27, wherein the elastomere encoder (8) can be produced by adding a filler, wherein the filler is strontium ferrite (SrFeO) and / or an iron alloy (NdFeB), wherein the elastomeric encoder (8) by adding a Filler of 20 to 40 vol.% Strontium ferrite (SrFeO), but preferably 30 vol.% Strontium ferrite (SrFeO), and / or 5 to 30% by volume iron alloy (NdFeB) modified elastomer mixture is produced and is covered by non-magnetic material.

29. Use according to at least one of claims 26 to

28, wherein the Elastomerencoder (8) as a band or plate with a thickness of lmm to 5mm and dimensions preferably of 1000mm length and 10 to 100mm width is present and / or composed of such bands or plates.

30. Use according to at least one of claims 26 to

29, wherein the Polbreiten or Polabstände the Elastomerencoders (8) are preferably from 100% to 400% of the effective sensor distance.

31. Use according to at least one of claims 26 to

30, characterized in that the orientation of the Elastomerencoder (8) a maximum of 5 ° from the conveying direction or circumferential direction of the elastic member (9) deviates.