Patent ID: 6589456
Filing Date: 2003-07-08
Classification: B29C

Abstract:
A method of compensating for mold changes in a toggle motor-driven clamping unit having a link housing, a movable platen with a movable mold, a fixed platen with a fixed mold, a toggle link mechanism interconnecting the link housing and the movable platen, and tie bars supporting the link housing, said method comprising:providing a combination of dogs and switches producing a combination of ON and OFF binary signals; dividing a mold thickness adjustable range between a position of the link housing for a thick mold of the greatest allowable thickness and a position of the link housing for a thin mold of the smallest allowable thickness into a plurality of sections, so that the number of divisional sections of the mold thickness adjustable range is within the number of the combination of the ON and OFF binary signals; determining the relationship of the position of the link housing when the movable mold contacts with the fixed mold to the any of the divisional sections of the mold thickness adjustable range; assigning extra elongations of the tie bar applied by the toggle link mechanism for desired mold clamping forces to each of the sections of the mold thickness adjustable range; moving the link housing forward in a state where the toggle link mechanism is locked up; detecting which sections the link housing is positioned in when the movable mold contacts with the fixed mold on the basis of the combination of ON and OFF binary signals provided by the switches, and; adjusting the position of the link housing so that the tie bars are elongated by the extra elongation for a desired mold clamping force, assigned to the section in which the link housing is positioned.