Mold attaching/detaching apparatus and mold attaching/detaching method

A mold attaching/detaching apparatus for detachably attaching a stationary metal mold to a stationary platen and detachably attaching a movable metal mold to a movable platen of a molding machine, the apparatus comprising:

• a plurality of platen-side attachments secured to the stationary platen and the movable platen, and
• a plurality of mold-side attachments secured to the stationary metal mold and the movable metal mold,
• wherein each of the platen-side attachments includes:
• a cam which moves between a locking position and a lock-releasing position, and which has inclined-locking grooves and inclined-pushing grooves, each groove being formed on an outer circumferential surface of the cam;
• an operating member which is adapted to move the cam back and forth;
• a ball-supporting member which is adapted to be inserted with the cam and which has ball-supporting holes, each hole having an axis extending at right angles to a direction in which the cam moves;
• a plurality of locking balls each of which is supported in one of the ball-supporting holes, is adapted to face one of the inclined-locking grooves, and is movable in the direction at right angles to the direction in which the cam moves;
• and
• a plurality of pushing balls each of which is supported in one of the ball-supporting holes, is adapted to face one of the inclined-pushing grooves, and is movable in the direction at right angles to the direction in which the cam moves,
• wherein each of the mold-side attachments includes:
• a ball-receiving member which has:
• (i) a hollow part that is adapted to be inserted with the ball-supporting member, (ii) engaging-locking grooves each groove being formed in an inner surface and adapted to face one of the locking balls, and (iii) engaging-pushing grooves each groove being formed in the inner surface and adapted to face one of the pushing balls,
• wherein when the cam moves from the lock-releasing position to the locking position while the ball-supporting member remains inserted in the ball-receiving member, the locking balls slide on respective inclined-locking grooves of the cam, and are moved outward in directions at right angles to the direction in which the cam moves, and are thereby set in respective engaging-locking grooves of the ball-receiving member, thereby fixing the mold-side attachment to the platen-side attachment, and
• wherein when the cam moves from the locking position to the lock-releasing position while the ball-supporting member remains inserted in the ball-receiving member, the pushing balls slide on respective inclined-pushing grooves of the cam, and are moved outward in directions at right angles to the direction in which the cam moves, and are thereby abut on respective engaging-pushing grooves of the ball-receiving member, thereby projecting the mold-side attachment from the platen-side attachment.