CZ20012905A3 - Measuring apparatus - Google Patents

Abstract

The invention relates to a measuring device and a method for continually determining the tensile forces of the chains in the chain conveyor belt of a scraper chain conveyor in the coal face area in coal mining. Known devices for determining the chain strain of a chain strand which is used in mining and which is moved in the conveyor are based on sensors being mounted on a chain link. When the chain link is stretched, a measuring signal is generated which is proportional to the stretching effect. Said signal is fed to a moveable receiving device that accompanies the measuring point and can be used as a storage unit, whereby the signal is fed via measuring lines. Said signal is received and processed. Information on the strains is thus provided with tremendous delay and involving high costs. The aim of the invention is to provide a method and measuring devices which enable to continuously determine the tensile forces of the chains in the chain conveyor belt of an operating scraper chain conveyor in order to almost simultaneously determine the strain ratio of the chain conveyor belt in relation to the permissible strain. According to the inventive method and said measuring devices, the deformation of the cribs of the chain links in relation to one another is determined as a change in distance in relation to zero strain, whereby said deformation is caused in a chain link and under strain. Said deformation is transformed into an electrical measuring signal that can be transmitted wirelessly and is transmitted to an output device for simultaneously outputting the strain.

Description

BACKGROUND OF THE INVENTION The present invention relates to a method for measuring, transmitting, transforming and processing a measured quantity displaying an instantaneous load of a conveyor chain chain up to a numerically proportional and / or branded output of a chain conveyor load. whose chain pulling forces are introduced from the conveyor drive through the chain starlets into the chain belt in the mining of hard coal.

D 2 suction_buckles

Known measuring devices for detecting deformations on a chain link of a moving chain belt and the deducible chain forces therefrom are based, for example, on adjusting the ohmic transducer of the measured values on the chain link, i.e. a measuring body, which produces a proportional measurement signal.

In this connection, relative changes in the length of the chain link arm are carried by one or more wires or semiconductor extension measuring bands fastened to the measuring body, which produce an electrical measuring signal equal to the relative resistance change which is fed via the measuring lines to the repositionable measuring signal receiver. which accompanies the measuring point and which is capable of being stored, where it is also captured and further processed until it is handed over to · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·

- 2 terminal devices.

In this way, it is possible, with a significant delay, to evaluate the captured signals, for example at a PC workplace.

Such measuring devices are suitable for operational examination in terms of location-dependent loading of the conveyor chain and possibly of the conveyor drives.

The drawbacks are obvious for the anticipated load information in continuous operation, since any load information obtained based on the evaluation of the measurement signal to the chain load and thus also the operation progress with a significant delay to the decision carrier and thus avoids timely intervention in operation in terms of current load for any desired load corresponding to the actual load condition.

U.S. Pat. Nos. 4,283,942 and 4,605,829 disclose load-measuring devices for detaching hoists when the maximum load in a stationary chain is reached. Also approaching the mutually opposing arms of the chain links under load is also used as a measurement principle. Strain gauges and, if necessary, touch switches to disconnect the lifting tool are used for load measurement. However, because of their shape, these measuring members are not suitable for use in a chain belt of a chain scraper conveyor which moves in the face wall during operation. Especially when passing through the drive areas where the chain star applies a force-tight force to the chain belt, such measuring members would be crushed.

US 4,566,339 discloses a wireless transmission method for

• t ·· · · ♦ • · • · · • • ♦ • • • · «··· ♦ · ♦ • • •  · · • • ♦ · ♦ · «· ♦ • • · • • • • • Φ • ·· ♦ · ·· • ·

measured values. The method described herein is based on analogue frequency modulation, wherein the voltage values that are transmitted by the strain gauge tape are converted into frequency changes. However, this method has the disadvantage that transmission errors are difficult to recognize and that transmission is disturbed by external influences that are very common in mining.

SUMMARY OF THE INVENTION

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a method and a measuring device which makes it possible to detect permanently tensile forces in a chain in an operating or moving chain conveyor in the direction of extraction of a directed chain scraper. in order to obtain and dispense load rates on one or more chain strands of the chain in terms of permissible load almost simultaneously to the instantaneous load.

The problem is solved by the fact that the tensile load in the direction of the chain belt caused or prevented by the transverse movement of two adjacent opposing arms of the chain links of the chain links is detected directly or indirectly as a change in the offset against the unloaded state by means of a sensor system. the active principle has stable static and good dynamic transmission properties and within the measuring device is converted analogue sensor signal into electrical, wirelessly portable, digital and coded measurement signal, which after transmission to and after reception via measurement signal receiver is further transmitted to its assigned a processing and output unit for simultaneous output of the instantaneous load of the chain branch, if possible.

· ·· »» ·· ·· • · · 9 · • · • • • • * · »· • • 9 9 • • • • · • · • 999 · • • • •  · • • • * ♦ • · ·· ·· ·· ··

DETAILED DESCRIPTION OF THE INVENTION

The indicator unit, which is arranged in the overall system of the measuring device as an end device of the measuring chain, can be provided, for example, in the area of a control panel in a mine building or in an above-ground control room.

The use of the following sensors has proved to be particularly advantageous for the measurement method.

Firstly, they are piezoelectric sensors. Due to the chain load resulting from the travel variations between the individual links of the chain links, they are converted into a compressive force by means of a spring element. A voltage is created at the output of the sensor, which is dependent on the magnitude of the compressive force.

These are resistance sensors, strain gauges or potentiometers. The travel variations resulting from the chain load generated between the links of the chain links are converted into a resistance change.

First, they are inductive sensors. The travel variations resulting from the chain load between the links of the chain links cause the movable receiving coil to be immersed in a stationary transmission coil, such as an immersion coil. The immersion coil is a capacitor with a variable number of windings. The output generates an electrical voltage proportional to the insertion depth and thus the chain load.

First, they are optical sensors. The variation in the path resulting from the chain load between the links of the chain links causes a change in the light intensity of the light beam, which, for example, impinges on a sensor sensitive

·· 99 • 9 • 9 • 9 • • t 9 * * ♦ · 9 9 • • * * · ♦ · • · • * · • 9 999 • · t • ♦ • 9 • * • • · 9 · 99 • 9 99 99

to the light that moves together with the chain link arm. The light intensity is converted by means of a photo resistor or a light-to-voltage converter to electrical voltage.

For the actual wireless transmission, conventional transmission systems are used in mining. The measurement signals are digitized and coded by the inverter. With this method, it is possible to detect, correct and eliminate transmission errors and erroneously incoming data. This is particularly important in a large number of mining interferences to allow reliable data transmission. Furthermore, the method of transmission provides the advantage that it is energy efficient because the controller controls the transmission of data so that the data is only transmitted when a certain amount of data has been stored in the memory.

For safety reasons, those parts of the measuring equipment that are installed inside the mine building, ie underground, require their own safe design.

·· • • tt ·· tt ’ * t tt in t • • • • • « • • • * ··· • • • • • • • • • « t · • ··· • t • • • • t • · • ·· t • • t • · ··

Claims (6)

A method of detecting, transmitting, transforming and processing a measured quantity displaying an instantaneous load of a conveyor chain chain up to a numerically proportional and / or branded output of a chain conveyor load as load information on a chain scraper conveyor operating as a continuous face conveyor whose chain pulling forces are introduced in the hard coal mining from the conveyor drive through the chain starlets into the chain belt, characterized in that the tensile load in the direction of the chain belt caused or prevented by the lateral movement of two adjacent opposing arms of the chain links is detected directly or indirectly its change of the distance from the unloaded state by means of a sensor system, whose operating principle has a stable static and good dynami In the measuring device, the analogue sensor signal is converted into an electrical, wirelessly portable, digital and coded measurement signal, which, after being transmitted to and received by the measurement signal receiver, is further transmitted to the processing and output unit assigned thereto. simultaneous output of the instantaneous load of the chain branch. 2. A measuring device for detecting, transmitting, transforming and processing a measured quantity displaying the instantaneous load of a conveyor chain chain up to a numerically proportional and / or branded output of a chain conveyor load as load information on a chain scraper conveyor the pulling forces are introduced from the conveyor drive through the chain stars to the chain • 9 ··· » 9 9 9 » • 9 * 1 9 9 9 9 9 9 • 9 9 9 • • 99 • • 9 · 9 • 9 • 9 9 • • 99 » 9 9 9 • 9 • 9 • 9 9 9 9 9 9 • 9 «9 99 99 characterized in that a sensor system is arranged between the chain link arms of the chain link, which detects, under tensile load in the direction of the chain link, the caused or prevented transverse movement of two adjacent opposite links of the chain link chain links directly or indirectly against a lightening state, and whose operating principle has stable static and good dynamic transmission properties, that inside the measuring device a converter is provided which converts an analogous sensor signal into an electrical, wirelessly portable, digital and coded measurement signal, and that it is behind the converter a measuring signal receiver is connected, which transmits it to the processing and output unit associated therewith for receiving the measuring signal, for simultaneous simultaneous output of the instantaneous load of the chain branch. A measuring device according to claim 2, characterized in that the variation in the spacing between the chain link arms is detected by means of piezoelectric sensors or receivers with an electronic analogue output in the form of a charge indirectly by means of the pressure or force of the two chain link arms. each other. A measuring device according to claim 2, characterized in that the variation in the spacing between the chain link arms is detected by means of resistance sensors or receivers with an electronic analog output in the form of a resistance or voltage change indirectly by applying pressure or force to the two chain link arms. articles against each other. Measuring device according to claim 2, characterized by: IN*  <··  IN IN* V w * • • · 9 · • « • • • • a · • · • · F • « • • • • · • • · • • and • • • • • « • • • ·· 4 · ·· • a characterized in that the variation of the spacing between the chain link arms is detected by means of an immersed armature inductive sensor with an electronic analog output in the form of a variation of inductance or alternating voltage directly by way of the two link chain arms opposite each other. The measuring device according to claim 2, characterized in that the variation of the spacing between the chain link arms is detected by means of optical sensor sensors with an electronic analog output in the form of a change in light intensity indirectly by way of two chain link arms opposite each other. .