DETECTOR OF MOLD TOUCHING POSITION IN MOTOR-DRIVEN DIRECT PRESSURE TYPE MOLD CLAMPING MECHANISM

摘要

PURPOSE:To eliminate the need of a limit switch, the positional adjustment of which is difficult, and make it possible to easily obtain a mold touching position by a method wherein the mold touching position is automatically detected when the detection command of mold touching position is inputted. CONSTITUTION:When a mold touching position detection command is inputted from an input means A, a torque limiting means B applies torque limitation to the servomotor E of a mold clamping shaft. A drive control means C starts pulse distibution so as to input to the error registor (d) of a servo circuit D in order to drive the servo motor E at low speed and at the same time under low torque, resulting in shifting a movable platen F to a fixed platen side. When molds abut against each other and the shifting of the movable platen stops, the value of the error registor (d) in the servo circuit D increases and is read by an error value reading means G so as to discriminate the read error value by a discrimination means H. If said error value is discriminated by the discrimination means H as over the set value, a mold touching position detection means subtracts the read error value from a pulse distribution, given to the error registor (d) in order to detect a mold touching position.