Ultrasonic washing apparatus and ultrasonic washing method

An ultrasonic washing method, comprising the steps of:

• putting an object to be washed from a side of a washing tank through an inlet formed in a first side wall of the washing tank, with the level of the cleaning liquid in the washing tank being kept below the height of the inlet in the side wall of the washing tank;
• closing the inlet with a door,
• letting deaerated cleaning liquid into the washing tank after the inlet door has been closed,
• ultrasonically washing the object within the washing tank,
• removing some of the cleaning liquid from the washing tank to bring the level thereof to a level below the height of an outlet formed in another side wall of the washing tank,
• opening a door covering the outlet, and
• discharging the washed object through the outlet.

An ultrasonic washing apparatus, comprising:

• a washing tank having side walls and a floor cooperating to define a washing chamber, said washing tank having an inlet opening formed in a first of said side walls and an outlet opening formed in a second of said side walls;
• an inlet door operatively associated with a shifting mechanism for shifting the position of an object to be washed, wherein said shifting mechanism is capable of charging the object to be washed into the washing tank from a side of the washing tank and discharging the object to be washed in the washing tank toward a side of the washing tank and is provided in the vicinities of said inlet and outlet,
• a storage tank for temporarily storing cleaning liquid,
• an ultrasonic signal generator, and
• a cleaning liquid flow control mechanism for controlling flow of cleaning liquid in said apparatus, wherein said flow control mechanism is operable to set a resting level of the cleaning liquid by shifting cleaning liquid from the washing tank to a storage tank at the time of putting the object to be washed into the washing tank through the inlet and at the time of discharging the object in the washing tank through the outlet, and to set a working level of the cleaning liquid by shifting cleaning liquid from the storage tank to the washing tank in preparation for washing the object.