| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a drum-type washing machine with inexpensiveness and low-vibration properties by restraining vibrations of a water tank at a start of spin-drying. <P>SOLUTION: The drum-type washing machine is provided with the water tank 42 including a drum 44 rotatably inside for housing a wash and elastically supported inside a washing-machine body 41, a motor 40, a rotational frequency sensing device 33 for the motor 40, a control part 31 for controlling rotations, and a vibration sensor 48 for the tank 42. The control part 31 urges the motor 40 to generate accelerative torque to accelerate a rotational frequency of the drum 44, raising it from a rotational frequency N1 smaller than a resonant rotational frequency Nc of a vibration system including the drum 44, the motor 40 and the tank 42 to that N2 larger than the frequency Nc. After sensing that an amplitude of the system at the frequency N1 becomes the minimum between the frequency Nc, the control part 31 raises the frequency of the drum 44 by a predetermined acceleration from the frequency N1 to the frequency N2, thereby allowing the motor 40 minimizing an accelerative torque necessary to pass the frequency Nc to be selected for the rotational acceleration of the drum 44 and providing the drum-type washing machine with inexpensiveness and low-vibration properties. <P>COPYRIGHT: (C)2010,JPO&INPIT |
