Method and apparatus for detecting unbalance amount of dehydrator

摘要

PROBLEM TO BE SOLVED: To detect the amount of unbalance using simple constitution, reduce costs, and enhance detecting sensitivity, reliability, and operability. SOLUTION: This device includes: a motor 12 driving and rotating a spin-drier 4; a rotation sensor 19 detecting the rotation of the spin-drier 4; a pulse length measurement means 18 for measuring a pulse length showing a rotating speed signal from the pulse signal of the rotation sensor 19; an operation control means 17 driving the motor 12 and shutting off power supply at a predetermined rotating speed computed on the basis of the pulse length measured by the pulse length measurement means 18; a pulsation amount detection means 21 which samples the pulse length measured by the pulse length measurement means 18, during the period after the shutting off of power to the motor and before a predetermined number of rotation is reached during the inertial rotation of the spin-drier, then calculates the amount of pulsation by eliminating speed components from pulsation caused by fluctuation in the speed of the spin-drier at the sampled pulse length, and then computes the integrated value of the amounts of pulsation for output; and an unbalance amount detection means 22 for computing the amount of unbalance showing the degree of unbalance of load in the spin-drier 4, from the integrated value of the amounts of pulsation computed by the pulsation amount detection means 21 and according to a predetermined expression.