US 6,402,998 B1 · Motor-driven mold clamping device

Abstract

A motor-driven mold clamping device includes a servo motor and a movable platen, with a toggle mechanism driven by the servo motor to advance and retract the movable platen for clamping a mold. The toggle mechanism has a crosshead associated with the movable platen. A setting unit is provided for setting a position of the movable platen, and a position detector is provided for detecting a position of the crosshead. A control unit is provided for approximating a correlation between the position of the crosshead and the position of the movable platen by using at least one mathematical function of a quadratic or higher order. The control unit calculates a calculated position of the crosshead by the at least one mathematical function with the position of the movable platen set by using the setting unit to control the position of the crosshead for the control of the mold opening and mold closing positions. The control of the position of the crosshead is made in accordance with the detected position supplied from the position detector and the calculated crosshead position.

Claims13

Dependent claims

A motor-driven mold clamping device comprising:

a servo motor;
a movable platen;
a toggle mechanism driven by said servo motor to advance and retract said movable platen for clamping a mold, said toggle mechanism having a crosshead associated with said movable platen;
a setting unit for setting a position of said movable platen;
a position detector for detecting a position of said crosshead;
and
a control unit for approximating a correlation between the position of said crosshead and the position of said movable platen by using at least one mathematical function of a quadratic or higher order, said control unit calculating a calculated position of said crosshead by the at least one mathematical function with the position of said movable platen set by using said setting unit to control the position of said crosshead for the control of mold opening and mold closing positions, the control of the position being made in accordance with the detected position supplied from said position detector and the calculated crosshead position, wherein said control unit being configured to divide a movable range where said movable platen travels into a plurality of regions and said control unit also approximates a correlation between the position of said crosshead and the position of said movable platen for each of the divided regions by using the mathematical function.

4 more elements

A method for controlling a movable platen, said method comprising the steps of:

providing a movable platen, a crosshead associated with the movable platen, a setting unit for setting a position of the movable platen, a position detector for detecting a position of the crosshead, and a control unit for dividing a movable range of the movable platen into a plurality of regions and for approximating a correlation between the position of the crosshead and the position of the movable platen for each region of the plurality of regions by use of at least one quadratic or higher order mathematical function;
detecting the position of the crosshead with the position detector, and providing a position signal to the control unit;
calculating a position of the movable platen based on the position signal and by the use of the at least one quadratic or higher order mathematical function.

Dependencies are inferred from the claim text.

Motor-driven mold clamping device

Life of this patent

Motor-driven mold clamping device

Life of this patent

Abstract

Claims13