SU537168A1 - Dragline Boom Protection Device - Google Patents

Description

(54) DRAGLINE ARROW PROTECTION DEVICE

one

The invention relates to the field of operation of excavators - draglines in open pit mining.

A device for protecting a dragline boom is known, comprising a long-haul and hoisting rope sensor, a pulse selection unit, a reversible counting circuit, a decoder, a reset unit, and actuating circuits.

A disadvantage of the known device is the low noise immunity of the device against the influence of external factors.

The aim of the invention is to increase the reliability of the protection.

This is achieved in that the proposed device is equipped with three protection control triggers, an alarm control trigger and a protection forcing unit, the outputs of the decoder and the reset node are connected to the inputs of the protection control triggers, and one of the inputs of the protection forcing trigger to the second input which is connected to the first protection control trigger, and the outputs are connected to the second and third protection control trigger.

FIG. 1 shows a block diagram of the proposed device; in fig. 2 is a schematic representation of boom protection zones.

The device contains sensors 1 and 2 of long and lifting ropes, selection unit 3 pulses, reversible counting circuit 4, decoder 5, trigger 6 alarm reset, triggers 7, 8 and 9 protection control, unit 10 forcing protection, reset node 11, actuators signaling circuits 12 and circuits 13, 14 and 15, respectively, of the first second and third stages of protection.

The device works as follows. When the voltage is applied, the protection control triggers 7, 8 and 9, as well as the reset node AND, are reset.

Before starting work, the excavator driver has to install the device into a working state, which is carried out in the following order. When the hoisting rope is loosened, the bucket is tightened to the pickup blocks until it triggers

limit switch stopping drive. With this signal 16 from the reset device, the control triggers 7, 8 and 9 are reset to their initial state. The hoist rope is then tensioned.

on the first position of the controller up to a certain effort, fixed by the time delay. In this case, the signal 17 triggers the reversible counting circuit 4 is reset, and the signal 18 switches the reset alarm trigger 6, which by its input unlocks the decoder 5 and activates the signaling circuit 12 on the termination of rope fixation.

The length of the lifting rope is equal to the control value LK. The removal of the bucket from the zone must be done in the reverse order. At the same time, from the sensors 1 and 2 of the long haul and hoisting ropes, pulses begin to flow, which, forming and regrouping in the selection unit 3, are transmitted to the counting inputs of the reverse counting circuit 4, the reverse tires of which are already installed in the desired position by the same selection node 3

The reverse counting circuit 4 begins to monitor the current total length of the pull and hoisting ropes / m + n. Information about the current total length of the ropes goes to the inputs of the decoder 5, the outputs of which fix certain values of the total length LO, Li, LZ and La, and

LO LI La La.

Upon the exit of the bucket from the extreme zone LO after triggering the device, the trigger 6 is switched to the operating state, thereby unblocking the remaining outputs of the decoder b, and the alarm 12 stops.

Boom protection device is ready to work. When the bucket enters the excavation process in the first stretching zone LI, the first control stage trigger 7 switches, issuing a command to the executive circuit 13 and activating the force unit 10. In this case, the drive is accelerated in the direction of rope extension. Under the action of the drive gear, the bucket must go out of the stretching zone.

In case the bucket continues to approach the boom and reaches the LZ zone within a period of time longer than the one specified by the force unit 10, then the trigger 19 switches the trigger 8 of the second control stage. In this case, the circuit 14 issues a command to slow the raising of the bucket.

Under the action of accelerating the pulling out of the traction rope and slowing the lift. The bucket must go out of the zone.

The action of the first and second stages of the protection control stops when the bucket crosses in the direction "from the boom of the LO zone." In case the bucket, approaching the boom, 5, after crossing the LI zone, reaches the La zone in a time less than the forcing specified by node 10 (high speed), then the trigger 9 switches the trigger 9 of the third control stage. In this case, circuit 15 reverses

0 actuator lift and triggers an alarm. Under the action of such potent means as the reversal of the lifting drive, the bucket leaves the stretching zone. In case the bucket is at the intersection of the LZ zone

5 continues to slowly approach the boom and cross the zone LS, then the trigger 9 of the third control stage switches.

The action of the third stage of control is terminated when crossing the bucket in the direction of Lenin from the boom of zone LI.

After the third stage of the boom protection has triggered, after the time specified by node 10, the second stage is triggered, see the dynamic action of the reverse mechanism

5 ascent in the case of crossing the LZ zone, and in the case of crossing the LI zone when the bucket moves in the direction "from the boom."

Claims (1)

Invention Formula A protection device for a dragline boom containing a sensor for long and lifting ropes, a pulse selection unit, reversible a counting circuit, a decoder, a reset node and execution circuits, characterized in that, in order to increase the reliability of the protection, it is equipped with three protection control triggers, an alarm control trigger and a protection boost node, and the outputs of the decoder and the reset node are connected to the control trigger inputs protection, the alarm control trigger and one of the inputs of the protection forcing unit, which the second input of which is connected to the first protection control trigger, and the outputs are connected to the second and third protection control flip-flops.