SU1514722A1 - Arrangement for reversible control of preventive braking of hoisting machine - Google Patents

Description

The invention relates to mine lifting machines with dual-mode safety braking and can be used mainly on single-end lifting installations inclined shafts and mine workings. The purpose of the invention is to improve the safety of lifting machines. To do this, the device contains a supply network of 13 compressed air, the main 1

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and 2 and duplicate 3 solenoid valves (EMC), operating braking pressure regulator, brake power cylinders (STS) 4 and 5, power supply _> DC, intermediate relay, safety braking relay, electrical capacitor unit, breaker contact of the direction of rotation of the machine additional adjustable reducing pneumatic valve 12 and disconnecting contact of the vessel overhang protection switch. In working condition, SCS 4 and 5 are powered through the EHR 1, 2 and 3 from the pressure regulator ₍ operating braking. With safety braking, the closing contact of the safety braking relay opens. When the lifting vessel (PS) moves upwards, the coil;

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The EMC 3 is de-energized and the SCR th and 5 are connected through the EMC 1, 2 and 3 to the pneumatic valve 12. The overpressure of the compressed air from the SCR 4 and 5 through the outlet valve 8 of the EMC 3 is discharged to the atmosphere. The setting of the pneumatic valve 12 provides a given amount of braking torque. Then the electrocondensers of the electrocondensers unit are discharged, the EMC coils 1 and 2 are de-energized and the CCTs A and 5 communicate with the atmosphere. When moving PS down the contact of the relay of the direction of rotation of the lifting machine is open, the electric capacitors are discharged and the STST 4 and 5 communicate with the atmosphere without delay. Similarly, safety braking is performed in the event of a PS elevation. 2 Il.

The invention relates to mine lifting machines with dual-mode safety braking and can be used mainly on single-end lifting installations inclined shafts and mine workings of the coal mines and the mining industry.

ABOUT

The purpose of the invention is "Improving the safety of operation of lifting machines."

Figure 1 shows the pneumatic diagram; figure 2 is an electrical diagram of the device reversal-selective control safety brake single drum lifting machine.

The device has the main solenoid valves 1, 2 and the same backup valve 3, connected by its distribution channels to the brake power cylinders 4 and 5, the operating braking pressure regulator (not shown) and exhaust relief valves 6, 7, 8, chokes 9, 10 s atmospheric output and the throttle 11, which is connected to the output of an adjustable reduction pneumatic valve 12 connected to the supply network 13 of compressed air. The coils 14, 15, 18 of the solenoid valves are included in the control circuit with a source of 17 DC power supply, a block of 18 electric capacitors, a diode 19, an intermediate relay

20 with closing contacts 21, 22, closing contact 23 of the safety braking relay, disconnecting contact 24 of the direction of rotation of the hoist machine, and disconnecting contact 25 of the vessel overrun protection switch.

The device works as follows.

In the operating state of the hoisting machine, the closing contact 23 in the brake control circuit is closed, the relay coil 20 is flowed by the current from the power source 17 and by its closing contacts 21, 22 supplies power to the coils 14, 15, 16 of the solenoid valves 1, 2, 3. All valves 1 , 2,

3 are included and the power cylinders 4, 5 of the brake with the operating braking pressure regulator report their distribution channels; The machine is controlled by the service brake. At the same time, during stopping and moving the machine in the direction of lifting the vessel upwards, the disconnecting contact 24 of the direction of rotation of the machine remains closed and the electrical capacitor unit 18 is in the charged state, and when the machine is moving backward, the contact 24 is open and the capacitor unit 18 is discharged.

In the mode of upward movement of the vessel, the switching contact 23 opens, which disables the relay

20, which is its contacts 21 and

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22 de-energizes the winding 16 of the backup valve 3 and disconnects the coil 14, 15 main valves 1, 2 from the power source 17. The backup valve 3 is turned off, and the main valves 1, 2 are turned off, because the charged unit 18 of electric capacitors through the circuit 25, 24 and the diode 19 begins to discharge into the coils 14, 15 of these valves. Turning off the backup valve 3, its distribution pneumatic channels are switched to the position in which the power cylinders 4, 5 brakes are disconnected from the operating braking pressure regulator and connected to the output of the adjustable pressure reducing valve 12 connected to the compressed air supply network 13. The overpressure of compressed air from the power 4, 5 cylinders of the brake through the relief valve 8 of the backup valve 3 is forcedly released into the atmosphere and thereby selects the "idle" brake travel. Then the compressed air continues to exit from the power cylinders 4 and 5 of the brake through the throttle 11 and the relief valve present in the reduction valve pneumatic valve 12. When the pressure of the compressed air in the power cylinders 4,

5, the brake is equalized with the pressure at the outlet of the reducing pneumatic valve 12, the air pressure drop in them will stop and be maintained constant, given by the setting of the reducing pneumatic valve 12. Accordingly, the set braking torque will be maintained, which prevents the lifting vessel from running on the rope. By the time the machine is completely stopped, the electric capacitors 18 have time to discharge, the main valves 1, 2 are turned off and the power cylinders 4 and 5 of the brake with the atmosphere communicate with their distribution channels; the car is braked by the full braking torque.

The required value of the braking torque and the braking mode of the machine is set by the appropriate setting of the reducing pneumatic valve 12 and can be adjusted in a wide range: from stopping the machine in free run-down mode without additional braking to braking its braking torque, approximately equal to 0.8 of the maximum value. This is reaching4722 6

It is possible to ensure optimal modes of safety braking of the machine, excluding the lifting of the lifting vessel on the rope

5 at different angles of inclination of the mine shafts and mine workings.

In the event of a safety braking of the machine caused by the opening of the lifting vessel protection switch, contact 25 of this protection in the brake control circuit is opened. Therefore, when disconnecting the relay 20, all three windings 14, 15,

15 16 are de-energized and their solenoid valves 1, 2, 3 are switched off simultaneously. Distribution pneumatic channels of the main solenoid valves 1, 2 spring-pneumatic

20 power cylinders 4, 5 brakes are switched to complete release of compressed air to the atmosphere directly through bypass valves 6, 7 and throttles 9, 10, which ensures forced braking and emergency stop of the machine within the path of acceptable vessel lifting.

During safety braking of the machine in the mode of moving the lifting vessel down, contact 24 of the relay of the direction of rotation of the machine is open, the electric capacitor unit 18 is discharged and the braking process takes place similarly to safety braking in case of lifting the lifting vessel through the exhaust valves 6 and 7 of both main valves 1, 2, which provides the required intensity and increases the reliability of the tor35

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Claims (1)

Claim A reversing-selective control of safety braking of the hoist, containing a compressed air supply network, a backup solenoid valve, the closing channel of which is connected to the operating braking pressure regulator, the opening channel — to the first adjustable exhaust valve, and the output channel to the first and second main closing channels solenoid valves, the opening channels of which are connected respectively through the second and third adjustable exhaust valves with at151 ^ 722 and the output channels - with the first and second brake power cylinders, a DC power source, the first output of which is connected to the first terminals of the coil of the intermediate relay and backup coils and main solenoid valves, and the second output through the closing contact of the safety braking relay and the first and 'second closing contacts of the intermediate relay, respectively, with the second terminals of the intermediate relay coil, the backup solenoid coil and the main electromagnetic valve coils the diodes and the cathode of the diode, the block of electrical capacitors and the opening contact of the relay of the direction of rotation of the lifting machine, about t and h a- 2θ In order to improve the safety of operating hoists, an adjustable pressure reducing valve and a disconnecting contact of the vessel overrun protection switch are inserted into it, the compressed air supply network is connected to the first adjustable exhaust valve through an adjustable pressure reducing valve, the first the output of the electric capacitor unit is connected to the first output of the DC power source, and the second output is connected to the anode di through the disconnecting contact of the vessel resurface protection switch One cathode through the disconnecting contact of the direction of rotation of the lifting machine is connected to the diode anode.