Device for the determination of the load of an electric chain hoist and procedure for the determination of the load

摘要

An apparatus for determining the weight of the load for an electric chain hoist having a lifting-lowering motor (12) and an inverter control (11) supplying an electric drive energy to the lifting-lowering motor (12 ), in which the lift-lower motor (12) rotates a pulley (15) to wind and unwind a chain (16) that is coupled to the pulley (15); the apparatus for determining the weight of the load comprising: motor current detection means (21) detecting a motor current supplied to the lift-lower motor (12) from the inverter control (11); and torque current calculating means (20) calculating a torque current by vector operation from the detected motor current; characterized by means of calculating the value of the current of the average torque of the movement (20) that successively calculate an average of the current of the torque calculated over a last previously determined period of time according to a lifting speed of the electric hoist of chain; and means for assessing the weight of the load (20) that assess whether the value of the weight of the lifted load is greater or not than a value of the overload weight previously determined by comparing the value of the current of the average torque of the movement with a set threshold.