The invention concerns a device for the inspection of steel wire ropes and a procedure for the use thereof, especially for the inspection of suspended steel wire ropes or chains.
The inspection device for the non-destructive inspection of steel wire ropes should serve to provide a location-independent inspection of steel wire ropes with various diameters that are to be used in an installed, freely suspended, or section by section tensioned condition.
The carrier cables that are especially used for elevator systems are deemed to be safety-relevant operating materials and only have a restricted useful life. This is the reason why the condition of the cables is to be inspected at regular intervals.
Such an inspection of lifting gear with conventional wire ropes is normally carried out in the form of an expert carrying out a visual inspection during recurring or regular inspections of the entire installation. It is normally the case here that wire breakages are determined and counted. A random testing of the cable diameter is also manually carried out.
An advanced inspection of the mounted steel wire rope is only possible after the rope has been removed so that a manual inspection can be carried out, or it has to be moved along by a person so that it can be manually and externally inspected.
The removal of the rope results in downtime and therefore unproductive times for the user of work platforms for example.
When moving along the rope, either the rope that is to be inspected is to be used although its condition is not known, or additional ropes have to be installed, whereby this also results in downtimes.
One example of a solution for inspections that go further than external inspections is presented in EP 0286712.
This describes a device for the inspection of ferromagnetic steel wire ropes, by which the lifting mechanism rope that is to be inspected, is driven through a field of permanent magnets, resulting in the stray fields being detected, whereby at least an induction coil that is to preferably encompass the rope and the measuring device is downstream from an electronic evaluation unit, it being intended in the invention that the stray fields are detected by means of differential measuring coils and that at least one additional induction coil with a downstream integrator emits a signal that reflects the cross-section of the rope, this being registered with an opto-electronic or electric scanning of the lifting mechanising rope that is to be inspected, the determined metallic cross-section and the sum of the stray fields, together with a path marker and a time marker.
EP 2 383 566 A1 describes a procedure for a computer aided optical inspection of a rope that comprises:—the provision of an image data set showing at least a section of the rope using a camera for example;—the provision of target values for a visual longitudinal elongation of wires relative to the visual longitudinal elongation of the wire in the image data set;—determination of a visual longitudinal elongation of the wires in the image data set, whereby the determination comprises an adaptation of a presumed longitudinal elongation to the image data set;—determination of at least one quality value by means of a quality standard as a function for the determination of a certain visual longitudinal elongation of the wires and the target values of the visual longitudinal elongation of the wires;—discrimination of visual positions within the image data set of the rope, with which at least one quality value exceeds or falls short of a predetermined allocated quality value;—the provision of the discriminated visual positions and a related system, together with a computer program.
Another procedure for the inspection of the suspension means of lifting mechanisms, especially ropes in elevator systems is described in EP 1 914 186 31 A1 with the following steps:—the permanent provision of an evaluation unit on a lifting mechanism,—temporary provision of at least one sensor device relating to a sensor for the determination of sensor signals as a basis for the inspection of the discard criteria of the suspension means on the lifting mechanism,—In operative connection of the permanently provided evaluation unit with the temporary provided sensor device for the evaluation of the determining sensor signals for the provision of information regarding the discard criteria as regards the suspension means.
It is the task of the invention to recommend a solution that remedies the disadvantages of the known state of the art and by means of which, steel wire ropes or chains can be inspected when fastened, without it being necessary for a person to move along them and inspect them manually, whereby the time that is required for the inspection is shortened and an improved proof of the inspection and improved documentation is provided.
An additional manual evaluation of the measured data is then no longer necessary.
This task is solved by the device that is the subject of the invention and the procedure for its use which is described in more detail on the basis of the illustrations and execution examples.
The main constituent parts of the sensor device, the signal and data processing unit 11 and the measured data evaluation unit 12 are of a modular design so that they can be adapted and combined for special applications.
This advantageous design enables the device that is the subject of the invention to be put to diverse uses such as when carrying out installation work on crane systems (e.g. gantry cranes) and as a direct connection with the crane control unit.
The device that is the subject of the inventions can also be installed at the outlet of winding machines for the manufacturing of steel wire ropes as a quality assurance method during the manufacturing process or in order to monitor ropes or chains on installation machines or crane systems.
The main field of application of the device that is the subject of the invention is certain to be the inspection of ropes and chains in the conveyance of people and loads (e.g. passenger elevators) and (interior) access systems in wind power plants.
The device that is the subject of the invention is formed by at least two housing segments 1, that are positioned around a test specimen 8 in a contactless form and are connected at an equidistance and are internally normal surface and centre-oriented when closed, such forming a supporting housing for all the other components.
These housing segments 1 are connected with each other by at least one of their longitudinal sides by means of mobile connecting pieces 2 for the defining of the clearance, rotation axis and the opening angles of each of the housing segments 1.
A suitable closing mechanism 3 is positioned on a freely definable pair of longitudinal sides of the housing segment 1 for the purpose of locking when in a closed condition and in order to apply the required pressing force.
The device that is the subject of the invention also has a multi-piece centering device 4 brought together by the housing segments 1 when in a closed condition, for the purpose of applying the relative force when decentralising the test specimen 8 from the guide axis of the centring device 4.
The device that is the subject of the invention also has a multi-piece magnetization device 5 that is brought together by the housing segments 1 when in a closed condition, this being for the generation of a magnetic field that flows through the test specimen 8 in segments, this field being homogenous and magnetically saturating, with 4 collinear longitudinal axes to the guide axis of the centring device 4.
The magnetisation device 5 has a measuring device 6 inside it with sensor elements 7 that are segmentable, automatic, electric contactable, and relate to the circumference of the test specimen 8 in sections, these also being equidistant arranged, these elements serving the measuring of the magnetic fields created by the test specimen 8 and the transferring of the measured signals to a signal and data processing unit 11.
Other features of the device that is the subject of the invention are
There now follows a more detailed description of the elements of the device that is the subject of the invention, on the basis of design examples:
The housing comprises two symmetrically identical segments 1 with a guide groove and markings for the exact positioning of the segments in relation to each other. The guide groove can be supplemented by mechanical positioning devices.
In another design form, the housing can comprise more than two components.
Connection 2 of the symmetrically identical housing segments 1 is formed by three fork joints with a joint rotation axis and fixation nuts by way of example. Numerous connecting elements 2 can be mounted for any number of housing segments 1. The fork joints that are depicted by way of example can be replaced by other rigid or flexible connecting elements 2.
Double transverse groove bolts with a threaded rod and knurled nuts serve as a locking mechanism 3.
The required pressure torque can be achieved by using mechanical (e.g. tensioning mechanisms, screw closures, pneumatic toggle clamps), hydraulic (e.g. hydraulic clamps) or electromechanical (a servomotor, a brushless dc, or a dc motor) locking mechanisms.
A special design is that the solution that is the subject of the invention can include a monitoring and controlling of the pressure force in the form of strain measuring strips that are inserted in the locking mechanism 3 or in the housing.
The centring device 4 should preferably comprise a rotationally symmetric, two-component guiding sleeve that exists double.
The centring device 4 can be of a flexible and variable design that enables diverse rope cross-sections and rope geometries to be centred, depending on the number of wires or strands, imbalance, and the winding direction. The geometries of the guiding sleeves or other centring devices 4 can hereby be adapted to the form of the test specimen 8 as required. The geometry of the guiding sleeves can therefore also be designed for the centring of chains.
The centring device 4 can be replaced by a pressure mechanism that can be integrated in a running gear if necessary. Mechanical sensors such as strain measuring strips or piezoelectric elements can be mounted in a running gear if necessary for the monitoring and controlling of the required pressure force.
The consideration behind the inventions also includes a multi-part designing of the centring device 4.
In another design, the centring device 4 can be contactless and electromagnetically controlled.
An alternative to saving, the centring device 4 can be realized with the assistance of the measured data evaluation unit 12, as this makes an exact depiction of the test specimen 8 possible, irrespective of its relative position within the device.
In a special design, the magnetization device 5 is formed of diametral magnetized, equidistant, rotationally symmetric arranged ring segment magnets 13 with an iron counterplate, with eight being on each half of the sensor, with four forming a common inner north pole and four forming a common inner south pole.
The magnetization device 5 also has a ferromagnetic iron counterplate for the concentration of the magnetic lines of force in the outer area.
The ring segment magnets 13 can be replaced with other forms and types of magnets or by electromagnets.
Additional sensors 7 can be used to monitor and control an electromagnetic magnetization device 6, in order to ensure an adequately high and homogenous magnetic flow.
The magnetization device 5 can be designed so that it can be adapted to various test specimen geometries.
Another possible design of the magnetisation device 5 is realised by a coil arrangement such as a Helmholtz coil for example.
The measuring device 6 is preferably to be in two symmetrical parts and form a holder for equidistantly arranged sensors 7, such as Hall sensors, it also being possible that it can comprise induction loop segments that encompass the test specimen 8. The measuring device 6 includes electric (signal) cable feedthroughs. In addition to the holder, the measuring device 6 also protects the sensor elements 7 against mechanical damage.
As an alternative, the measuring device 6 can also be mounted outside but in close proximity to the magnetization device 5.
The positioning of the sensor elements 7 that are included in the measuring device 6, can be automatically controlled by a mechanism and the output signals can therefore be adapted to the geometry of the test specimen.
The measuring device 6 can be of a multi-piece design.
In another design, the measuring device 6 converts analogue sensor signals into digital measured values and transmitted between the housing segments 1.
The measuring device 6 can be adapted to various test specimen geometries. An example for this is depicted in
Another advantageous design of the device is one that contains infrared sensors for the scanning of the surface profile of the steel wire ropes or chains that are to be inspected, in order to obtain an improved differentiation between various types of faults such as corrosion or surface soiling.
A position sensor 9 can also be in the form of an incremental shaft encoder or as an optical sensor (e.g. laser).
A signal and data processing unit 11 can be divided on housing segment 1 or it can be positioned centrally. The signal and data processing unit 11 is able to record, store, and transmit all the measured data simultaneously at all times of measurement.
A measured data evaluation unit 12 can classify faults automatically by performing a feature extraction from the measured data. The collected data are entered in a database 16 that is either inside or outside the device, so as to ensure a traceability of the measurements and render temporal changes of the test specimen 8 between different measurements discernible.
It is also possible to enter target values and the specific characteristics of the test specimen 8 in the database 16 in advance, so that an immediate pattern recognition and fault classification can be ensured.
The evaluated data can be output for further processing. The measured data can hereby be transferred to a terminal device 14 that is able to visualise or store data in a graphical, figurative, tabular form or in the form of a measured data file. As an alternative, a visualisation possibility (e.g. a screen) can be mounted on the device. The transfer of the measured data to the terminal device 14 can be carried out by means of a wireless data transfer (e.g. WLAN).
The measured values evaluation unit 12 does not necessarily have to be connected to the signal and data processing unit 11.
A signal processing algorithm that is included in the measured data evaluation unit 12 means that the centring device 4 is not required.
The procedure for the use of the device that is the subject of the invention shall now be explained on the basis of the signal flow diagram
Additional advantageous designs of the solution that is the subject of the invention are as follows, whereby this is non-conclusive:
It is also possible to initialise the measured value recording by means of the incremental shaft encoder of the position sensor 9 so as to ensure a conformity between the measurement point and the corresponding measured value.
An immediate checking of the test specimen identity is possible should the target values for the diameter, imbalance, number of wires/strands, the winding direction [right/left], etc. have been entered in the used database 16.
An inspection of other rope elements such as thimbles, is also possible using an optical imaging process.
Typical applications for the device that is the subject of the invention and the 19 proceedings for its use are:
The device that is the subject of the intervention can be permanently installed by combining the sensor 7 and the signal and data processing unit 11, and thereby ensure a permanent monitoring of the installation that is to be inspected. The feature of the device that suffices for this is the early fault detection in real-time that is ensured by omitting the advanced evaluation of the measured data without the measured data evaluation unit 12.
Specific examples for this are:
The device can be used in a mobile form after it has been coupled with a drive system that should preferably have a self-sufficient source of energy.
This enables the following typical applications to be stated:
1. Housing segment
2. Connecting piece
3. Closing mechanism
4. Centring device
5. Magnetization device
6. Measuring device
7. Sensor element
8. Test specimen
9. Position sensor
10. Sensors for an emission of electromagnetic waves
11. Signal and data processing unit
12. Measured data evaluation unit
13. Ring segment magnet
14. Terminal device
15. Energy supply
16. Database
Number | Date | Country | Kind |
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102019004240.9 | Jun 2019 | DE | national |
Filing Document | Filing Date | Country | Kind |
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PCT/EP2020/025266 | 6/8/2020 | WO |