Patent ID: 7478547

Claim:
A drum washing machine comprising: a cylindrical drum including a front portion formed with an access opening through which laundry is put thereinto, the drum having a substantially horizontal axis of rotation; a DC brushless motor having a rotational shaft directly connected to a rear of the drum, thereby rotating the drum; current detecting means for detecting an electric current flowing through the motor; torque control means for vector-controlling the motor based on the current detected by the current detecting means, so that torque developed by the motor becomes optimum at least in a wash operation and a dehydration operation; and laundry weight estimating means for accelerating the motor with a maximum output torque, which is developed when determining that a rotational speed of the motor is between a first rotational speed at which the laundry is assumed to start falling from an uppermost part of an inner periphery of the drum when as the rotational speed of the motor is reduced from a high speed side and a second rotational speed at which the laundry in the drum is assumed to start sticking to an uppermost part of the inner periphery of the drum, thereby estimating a laundry weight according to a q-axis current value in the vector control during an accelerating period.