DD264818A3 - SAFETY LOOP FOR MONITORING A REMOTE CONTROLLER OF A BAND PLANT - Google Patents

Abstract

Safety loop for monitoring a remote-controlled conveyor of a conveyor system with two or more, locally far away drives, especially in opencast mines for Gurtbandfoerderer. According to the invention, the object has been achieved in that a safety relay, an opener of an overvoltage relay, which is parallel to the safety relay and the opener, all system-typical Sicherheitsabhaengigkeiten for confirmation of the necessary state with a respective Schliesser and another Schliesser as a state statement for in a series circuit for each drive a Kraftschaltgeraet are interconnected. A contactor of the safety relay is circuit-wise effective in a quiescent current drive lock of the respective drive.

Description

For this 1 page drawings

Field of application of the invention

The invention relates to a safety loop for monitoring a remote-controlled conveyor of a belt system with two or more locally far apart drives, especially in opencast mining belt conveyor.

Characteristic of the known state of the art

There are controls and interlocks between different conveyors or different drives of a conveyor known, which are produced via coded or uncoded signals. Their degree of fault information or interference control security can be increased by redundancy or by multiple interlocking. Simple, so-called relay closed-circuit loops are known for other purposes and thus represent the state of the art. The disadvantage here is the high circuit complexity and not one hundred percent security against interruptions, ground faults, Aderschlüsse and external voltage potentials, thus against all possible external and internal errors to be protected. Furthermore, there is known a circuit arrangement for locking between spatially separated mobile and / or stationary equipment or systems, DDI ¹ S 230494, wherein when using DC voltage suitable relay link with double use of a single Leitungsadsr for simultaneous back and forth information or locking is present and an OR gate consisting of a high and low resistance branch is used. With this circuit arrangement no locking is feasible, which prevents a malfunction even with ground fault or external potential.

Also known are technical solutions, such as DE-PS 3130809 and DE-PS 2623449, which show certain circuits and interlocks to realize the synchronization of tape devices and the connection of the individual conveyor belts with each other. However, these solutions have the disadvantage that when errors occur, such as ground fault, external potential or wire termination, a malfunction of the respective arrangement is caused and thus larger incidents in band operation can occur.

Object of the invention

The aim of the invention is to realize a safety loop for monitoring a remote-controlled conveyor of a belt system with two or more, locally far away from each other drives, with relatively little circuit complexity all possible internal and external errors such. B. Earth fault, external potential, wire termination and interruption to> one cause fault.

Explanation of the essence of the invention

The invention has for its object to provide a safety loop for monitoring a remote-controlled conveyor of a belt system with two or more, locally far apart drives, with a gegensei .. ,, Dependence of the drives is a prerequisite to a Einzelzuschaltuno or individual shutdown of a drive prevent u. According to the invention, the object has been achieved by daf. in a series connection for each drive a safety relay, an opener of an overvoltage relay, which is parallel to the safety relay and the NC, all plant-specific safety dependencies for confirmation of the necessary state with a respective NO and another NO are connected as a state statement for a power switching device.

A closer of the safety relay is circuit-wise effective in a quiescent current drive lock of the respective drive.

Due to the series connection of the individual switching contacts of a respective drive in the safety loop, a simultaneous or slightly delayed (I s-2s) connection of all drives is a basic requirement when starting up the sand system. Thus, switching operations due to sources of error or external influences in a single locking level of a drive or in the safety loop never lead to the independent startup of a drive. From this, the advantages according to the invention can be derived, because this avoids large-scale accidents on conveyor systems. Furthermore, a little circuit complexity is necessary to equip or equip tape systems with it.

embodiment

The invention will be explained in more detail with reference to the drawings

 They show:

Fig. 1: a safety loop and Figure 2: the locking of a drive.

In the described embodiment is an embodiment of the inventive solution for a Tagabaubandanlage with a belt conveyor, with two drives, a head and rear drive. The two drives are

2000m away from each other and remotely controlled from a central control room.

To avoid external or internal sources of error such as Cable break, short circuit, wire termination, ground fault and External voltage potential in the drive lock or in the quiescent current loop an unwanted switching signal for one of

To prevent both drives, the invention of the inventive solution made necessary. As a basic principle was the

Closed-circuit release applied. Referring to Fig. 1, a safety loop for a head and rear drive variant is constructed as follows: A potential-insulated DC voltage source 60V, which with a variable resistor and output with the necessary Fuse elements is fitted, follows for the head drive level 1 Din safety relay 11, an opener 12a of the overvoltage relay

12, which is parallel to the safety relay 11 and the opener 12 a, a closer 17, which all necessary

Safety features and dependencies such as ripcord, all stop, voltage monitoring u. ä. represent L or 0 as a function

should and a closer 18, which signals the circuit state of Kraftschaltgorätes the head drive in the form of a

Series. Furthermore, for the Hockantriebsobene 2, the series connection with the safety relay 21, the opener 22 a of Overvoltage; relay 22, which is parallel to the safety relay 21 and opener 22a, the shutter 27, which is for the Heckantriebsebene 2 represents the necessary safety devices and dependencies as a function of L and 0 and the Normally open 28, which signals the switching state of the power switching device of the rear-wheel drive, continued. This safety loop can be without major problems on a certain number of existing drives a conveyor

expand a belt system by per drive level extends the safety loop with the elements described above and the necessary DC voltage is changed to the appropriate value, and the parameters of the used

Relay can be adjusted. Referring to Fig. 2, a lock for the head drive of the belt system is shown, which for each further drive the

same construction hat.

in the circuit arrangement, a time relay 14 with a shutter 19, welchar represents the switch-on command for the drives, in

Wired series. Parallel to this series connection is a parallel circuit of the opener 14a of the timing relay 14 and the Normally open 11 a of the safety relay 11 of the head drive level 1 of the Sicherhoitsschleife and a parallel to this circuit in series

arranged Relaiii 12 connected.

A NO 16a of the relay 16 is now on the undervoltage release 16 (quiescent current) of the power switching devices of the respective Drive in the form of a series circuit twisted. The solution according to the invention works as follows: When not switched th drives the undervoltage release 16 of the power switching devices is not activated because the relay 16 under Voltage is and thus the shutter 16a is closed. The drives, head drive and rear-wheel drive, are in the application

Slightly delayed switched on, first head drive and about 1 s to 2 s after rear-wheel drive. Thus, the shutter 19 in jedor

Locking level of the drives closed. About the timer 14, the opener 14a is about 2s to 4s still closed to the Override delay of the drives. In the safety loop of the shutter 18 of the head drive level 1 and the shutter 28 of the rear drive level 2 with switching

the drives are closed by a switching action of the power switching device. When the condition of the

Safety devices and dependencies for the belt system are the closer 17 and 27 of the respective level ebenfallo

closed and the safety relays 11 and 21 are energized. Thus, in the respective drive lock the

Normally open 11 a of the safety relay 11 is closed. The relay 16 is thus still under tension and the Undervoltage release does not take effect. Due to the series connection of the individual dependent switching contacts of the individual Antriobsebenen in the safety loop is

a concurrent or, as in the case of application, delayed transmission of the drives is a basic requirement for the

Commissioning of a conveyor * of a conveyor system. Thus cause switching operations due to sources of error or External influences, such. B. foreign potential, ground fault, short circuit, wire termination, etc. in a single Verschriogelungsebene a Drive or in the safety loop never for independent (permanent) start of the drive. In the case of application is the Special feature given that in case of a faulty connection of a drive, this for a short period of time until the opening of the opener

14a of the timing relay 14 starts in the lock and only then the undervoltage release 15 of the power switching device is effective and thus the drive shuts off again. The brief start of the drive in case of failure is without consequences, but it is possible to thus the switch-on condition of the drives of the belt conveyor, only head drive and delayed rear-wheel drive, meet and still be able to monitor all running conditions constantly. Furthermore, occurring sources of error, such as wire termination or external potential, which automatically lead to voltage increase in the safety loop, detected by the overvoltage relay 12 or 22 and the safety loop is interrupted, whereby a shutdown or no permanent connection of the drives of the belt conveyor is completed.

Claims (3)

1. safety loop for monitoring a remote-controlled conveyor of a belt system with two or more, locally far away from each other drives, especially in opencast mines, with a potential-separated power supply, relays and switching elements for more system-typical safety dependencies of each drive, characterized in that in a series circuit for each drive a safety relay (11), an opener (12a) einos overvoltage relay (12), which is parallel to Sicherheitsroiais (11) and the opener (12a), all system-typical security dependencies to confirm the necessary state of this with a respective closer (17) and another NO (18) are connected as a state statement for a power switching device of the drive. 2. Safety loop according to item 1, characterized in that a closer (11 a) of the safety relay (11) engages circuitry in a quiescent current drive lock of the respective drive. 3. Safety loop according to item 1, characterized in that the overvoltage relay (12) responsive to a voltage of higher than the maximum nominal voltage of the safety relay (11).