| 摘要 |
PURPOSE:To effect the set-up of mold tightening force with a metallic mold closed and shorten the time of automatic tightening force set-up by setting up the mold tightening force with stopping the rotation of a tie-bar nut when the mold tightening force signal that coresponds to the number of rotation of a tiebar nut has reached a set value. CONSTITUTION:A limit switch 19a is fixed at the position where rated mold tightening force is developed when metallic molds 7' and 8' that contact each other at the position where the limit switch 19a is actuaged by a striker 20 are tightented by high oil pressure After metallic molds 7' and 8' that were changed are mounted, low pressure oil is supplied to the cylinder 4 to prevent their dismounting, and a tie-bar nut 17 is rotated to extend the toggle. Since the time when the limit switch 19a is actuated by the advance of a piston rod 15, a mold tightening signal that diminishes continuously to values smaller than the rated mold tightening force signal that is obtained from a mold tightening force signal generating device 21 is input to the control board and there it is compared with a set mold tightening foce. When both signals match, the low pressure oil is cut off and the rotation of the tie-bar nut 17 is stopped. |
