Overload-supervisory equipment for an electric load-carrying device.

p0001The invention relates to a conveyor load monitoring device for an electrical conveyor system in mining, which has an armature current and speed control of the conveyor machine motor and measuring instruments for the armature current and the speed.

p0002Especially with conveyors with high conveying speeds, eg 12 m / s, occur in an overcharge to dangerous situations. Overloading can both upward and downward travel occurring and is caused by eg not work as intended discharged buckets or by a lack of weight balance.

p0003When downward conveying may occur in case of overload in Schachtendbereich for safety braking, because the Carrier the Einhängelast electrically can no longer brake or, in extreme cases, to a rope slide with then sometimes considerable consequences. When upward conveying it can in case of overload to damage cases to the conveyor motors or the power supplies come, this particular with three-phase carriers with their thyristors with possibly serious consequences.

p0004The object of the invention to provide a conveyor load-monitoring device for a powered AC or DC Supply System in the mining industry, in which an overload is detected with certainty before the aforementioned consequences may occur. The recognition is intended to be based on the amended by the overload dynamic behavior of the conveyor in order to avoid the potential for a conveyor load-monitoring device in the idle state error.

p0005The object is achieved in that the Drehzahlmeßgerät the conveyor system is connected to a speed differentiator via a matching amplifier, which is connected with conventional detectors. A differentiation dv / dt of the conveying speed is associated with a measuring window following the speed limit at which the initial disturbances have subsided, a meaningful, reliable for assessing the instantaneous load situation of the conveyor system available. So is a very beneficial unprecedented good conveying load monitoring in a conveyor in mining possible.

p0006In an embodiment of the invention provides that the output of the speed differentiator is connected to the input of a differential amplifier is connected to the well of the output of a matching amplifier for the armature current. So advantageous is also a torque monitoring of the conveyor system, the torque monitoring not only monitors the armature current, the so considered only the engine torque, but particularly advantageous, the total torque, which is also determined by the moving mass of the conveyor basket and rope. The conveyor load monitoring according to the invention thus goes in a significant way beyond the previously known motor torque monitoring, the differential amplifier is also connected to conventional detectors.

p0007The limit monitors act on an evaluation logic, which monitors the proper operating conditions and respond in a predetermined range is exceeded. Monitoring will advantageously both on the conveying speed and the acceleration and the maximum armature current.

p0008The monitoring device is designed to be redundant in all parts to meet the requirements concerning mining safety equipment and acting on a contactor control, which is designed in a known manner according to the quiescent current principle. This results in a total mining-oriented training the conveyor load monitoring device.

p0009Further advantages and details of the invention emerge from the following description of an embodiment, with reference to the drawings and in conjunction with the subclaims. Show it:<dl id="dl0001"><dt>1 shows</dt><dd>the suspended load monitoring device in two-channel version with maximum feed load supervision in their electrical integration into the transport system and</dd><dt>FIG 2</dt><dd>the circuit of the conveyor load-monitoring device in a single-channel version with maximum feed load supervision.</dd></dl>

p0010In Figure 1, 1 denotes the carriers motor whose armature current is fed through two channels using the shunt 2 and the coupling members 3 and 4 of the suspended load monitoring device 10th In the event that the carrier is already a Abgriffsmöglichkeit for the armature current, the signals for the armature current on the dashed lines drawn pathways 9 are abandoned.

p0011The speed of the drive pulley is formed on, preferably as Reibradtachometer, Tachogenerators 5 and 6 and also picked up 10 and 11 abandoned the suspended load-monitoring devices. If the carrier already has corresponding taps, there is a task in accordance with the broken pathway. 8

p0012The suspended load monitoring device 10 is shown in a version with a maximum feed load monitoring in FIG. 2 The monitoring device 11 can without the maximum conveyed load monitoring, so simplified in redundant Auführung be formed.

p0013Signals 12,13,14, 15 and 16 are discharged from the two devices 10 and 11. FIG. The signal 12 represents "maximum feed load is exceeded," the signal 13 "exceeded suspended load" for channel 1, and the signal 15 "exceeded suspended load" for channel 2, and the signal 14: "Modal tripping at a speed V ≧ 4 m / s as well as the signal 16, the redundancy monitoring, advantageously via a clock signal.

p0014In FIG 2, showing a single-channel circuit design and can be carried out both in the conventional analog technology and digital in a computing unit, 20 denotes the motor carriers and 21 the tacho. These are as well as the other electrical equipment in the usual symbols.

p0015The signals of the conveying machine motor 20 and the tachometer dynamo 21 pass via matching amplifiers 24 and 23, in this interposition of a shunt 22, directly or after processing to the limit sensors 27-36, the outputs of which are respectively designated. The signal processing of the actual speed value from the tacho 21 takes place following the matching amplifier 24 in addition to the straight-through processing, in execution of the main concept of the invention, also on the speed differentiator 25, in which an acceleration-dependent signal dv / dt is generated. From the output of the speed differentiator 24, the acceleration signal, as well as the signal from the output amplifier 23 for the armature current to the differential amplifier 26 abandoned, which forms a value I-dv / dt and the limit detectors 33-36 for the upcoming moment of the overall system abandons ,

p0016The conventional detectors 27-32 and 35 and 36 act on a computing unit 37, for example, a Simatic logic unit of Siemens, which according to the dargestellen blocks signals 38 for the maximum feed load at V ≧ 4 m / s and 39 maximum for conveying load after a emits predetermined time.

p0017The circuits shown in FIGS 1 and 2 are a two-channel design interchangeable in any way against simplified versions, eg with hanging load monitoring without maximum conveyor load supervision or in a single-channel design. In all cases, it is merely varied designs that make in the same way from the basic principles of the invention use.

p0018The conveyor load monitoring device according to the invention is suitable for both DC-carriers (regulated and controlled) as usable for carriers with AC drive (synchronous or asynchronous). In all cases the present invention, in the dynamic state, an overload be determined, monitoring is advantageously applied.