Toggle-type die clamping unit of an injection molding machine

Abstract

A toggle mechanism is supported at the front face of the housing and a forward end of the toggle mechanism is connected to a back face of the movable platen. Upon the closing and opening of dies, the toggle mechanism is stretched and contracted to move the movable platen forward and backward along the tie bars. An automatic control device calculates, before the dies are mounted, from a die thickness input and the kind of the dies input, such a stop position for the link housing as impart a target value to the stretching/contraction amount that the toggle mechanism has when the dies are in closed state, and calculates, from the kind of the dies input, an appropriate contraction amount greater than the target value, and the automatic controlling device moves the link housing to the stop position calculated and the toggle mechanism by the appropriate contraction amount calculated.

What is claimed is:  
     
         1 . A toggle-type die clamping unit of an injection molding machine comprising: 
 a base;    a stationary platen fixed on the base and configured to retain a stationary die;    a movable platen arranged opposite to the stationary platen and configured to retain a movable die, the movable platen being configured to be supported on the base in such a state as to be movable in forward and backward directions;    a link housing arranged on the base behind the movable platen and adjustable in position in the forward and backward directions;    a toggle mechanism mounted to a front face of the link housing and having a forward end which is connected to a back face of the movable platen, the toggle mechanism being configured to have its stretching/contraction amount controlled so as to move the movable platen forward and backward to close and open the dies;    a detector configured to detect a position of the link housing on the base and    an automatic controlling device configured to control a stop position of the link housing,    wherein, before the dies are mounted, the automatic controlling device calculates, from a die thickness input, such a stop position for the link housing as impart a target value to the stretching/contraction amount that the toggle mechanism has when the dies are in closed state, and the automatic controlling device moves the link housing to the stop position calculated.    
     
     
         2 . A toggle-type die clamping unit of an injection molding machine comprising: 
 a base;    a stationary platen fixed on the base and configured to retain a stationary die;    a movable platen arranged opposite to the stationary platen and configured to retain a movable die, the movable platen being configured to be supported on the base in such a state as to be movable in forward and backward directions;    a link housing arranged on the base behind the movable platen and adjustable in position in the forward and backward directions;    a toggle mechanism mounted to a front face of the link housing and having a forward end which is connected to a back face of the movable platen, the toggle mechanism being configured to have its stretching/contraction amount controlled so as to move the movable platen forward and backward to close and open the dies;    a first detector configured to detect a position of the link housing on the base;    a second detector configured to detect the stretching/contraction amount of the toggle mechanism; and    an automatic controlling device configured to control a stop position of the link housing and the stretching/contraction amount of the toggle mechanism,    wherein, before the dies are mounted, the automatic controlling device calculates, from a die thickness input and the kind of the dies input, such a stop position for the link housing as impart a target value to the stretching/contraction amount that the toggle mechanism has when the dies are in closed state, and calculates, from the kind of the dies input, an appropriate contraction amount greater than said target value, and the automatic controlling device moves the link housing to the stop position calculated and the toggle mechanism by the appropriate contraction amount calculated.    
     
     
         3 . A toggle-type die clamping unit according to  claim 2 , wherein the automatic control device calculates the appropriate contraction amount when the type of dies input designates spring-incorporated-type dies incorporating springs, said appropriate contraction amount being corresponding to an opening amount of the dies opened by the springs.