SU235264A1 - DEVICE FOR SAFETY BRAKING OF THE LIFTING MACHINE - Google Patents

Description

The known devices for braking hoisting and lifting machinery, containing an electrically controlled pressure regulator with a source of constant control spun and a unit comparing the magnitude of the set and the actual deceleration with the amplifier, do not provide the set deceleration during safety braking and sufficient reliability of the lifting machine.

In the proposed device, the control winding of the pressure regulator is connected at the output of the above-mentioned comparison node through the threshold element and into the circuit of the source of the constant control signal.

The drawing shows a schematic diagram of the proposed device, on which the following conventions are adopted: TG - tachogenerator; PV - semiconductor rectifier; . p - discharge resistance; C - differentiating circuit capacitor; - resistance of the differentiating circuit; R is the resistance of the delay setting circuit; Ry is the resistance of the installation of the magnitude of the specified retardation - resistance of the comparison circuit between the target and actual deceleration magnitude; UY - DC semiconductor amplifier; I / S - relay control current output circuit amplifier UY; PE - threshold element (zener diode); Ry is the resistance of the installation cut-off circuit; / (ГГ and ./(7Я2 - block contacts of the contactor brake contactor contactor; ОУ - winding

control of the pressure regulator; RD - pressure regulator for safety braking; KR and KP-i - flow-through cameras regulated1; 3 - spool; I am the spring; St - glass limiting; ZS - flap.

With the commemoration of the current in the winding of the OS, the AP gate covers the outlet of the chamber / sya, creating the maximum pressure in the chambers and the KP-i. Spool under

action of the working medium (oil, air, etc.), srpma prula1nu P, occupies the upper position, connecting the cavity of the safety brake cylinder (CPT) with a source of pressure of the working medium. As a result, the safety brake is released.

In the absence of current in the control winding of the OS, the ES gate opens the outlet of the chamber KR completely, ensuring the exhaustion of the working medium and the reduction in pressure to KPi and K.PZ. Under the action of the spring, the spool moves to the lower position and connects the cavity of the CHD to the exhaust. Disconnecting it from the valve body causes the brake to slow down.

Any intermediate current reduction in the control winding of an op-amp ensures that the intermediate pressure in the CLP is obtained and that a given braking force is created.

Into the control winding, the current is supplied either from a source of a constant excitation signal, or from a node comparing the set and actual deceleration of the DC with the amplifier VY.

In the US node, the actual magnitude of the delay .leHHH is characterized by the voltage taken from the resistance jRj differentiation1; its circuit RC connected via the rectifier PV to the TG chooheater. A voltage proportional to a given deceleration value is removed from a 1π1 resistor and may vary for specific resistance conditions.

The indicated voltages are supplied oppositely to the resistance R, and therefore the magnitude of the voltage generated from this resistance is iroporistic to their difference and characterizes the magnitude of the mismatch between the actual and given decelerations. The error signal, amplified by the UE amplifier, is fed to the OA winding.

During normal operation of the pick-up machine, only a full constant suppression comes into the OS control winding, which ensures the braked state of the safety brake.

When a safety braking command is received, the control winding of the OA with the KTUi contact is disconnected from the source of the continuous control signal, and with the contact / SGNa is connected through the amplifier VJ to the comparison node. Since the braking has not come yet, the 1 machine moves with the initial speed and the drive control signal at the amplifier output in the OC winding is zero.

Under the action of the spring, the spool moves to the lower polo} of the kenne, separates the QY7 cavity from the pressure source and connects it to the exhaust (drain) outlet. The expiration of the working medium from the CLT will occur as long as the actual amount of deceleration does not exceed the specified

the setpoint is such that the current signal is mismatched, which enters the OS control winding, will be sufficient to create an intermediate pressure in the KPi and KPz chambers of the regulator, and the spool will occupy the intermediate position and block the drain outlet, keeping the input from the pressure source closed. The steady-state braking force will correspond to the resulting steady-state pressure in the CLP, which ensures a constant predetermined amount of deceleration of the hoist machine during safety braking. For this, the deceleration setting is always selected.

slightly lower than the required specified deceleration.

Thus, at any load of the lifting ramp, the safety braking mode will be executed with a predetermined

slowing down.

To limit the magnitude of the error signal at the output of the amplifier, a threshold element PE (, zener diode) is included, which limits the amount of current

misalignment entering the OA winding and prevents the pressure regulator from being overregulated in the direction of opening the hole to the pressure source. Any complication of the regulating circuits by the pressure regulator leads to a safety braking of the mask with a delay for which the brake is designed, but not more than 5 m / s2

Subject invention

Device for the safety braking of the lifting machine, containing an electrically controlled pressure regulator with a constant control source

and a node comparing the magnitude of the specified and actual deceleration with an amplifier, characterized in that, in order to ensure the specified deceleration and increase the reliability of the machine, the control winding of the pressure regulator is connected at the output of the specified node to the constant-signal source.

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