Method and apparatus for controlling the nozzle engagement in an electric injection molding machine

Abstract

So that the injection nozzle (1) in an electrically driven injection molding machine may be driven free of shock into engagement with the mold (10), a spring has been interposed until the present time. The invention now proposes to delete this spring. The injection nozzle (1) is clamped between the stationary mold (10) and the injection unit (4) by two tie bolts or shafts (9) by the electric motor drive. Initially, the injection nozzle (1) is driven into engagement free of shock, for instance by presetting a brake ramp. Thereafter, the nozzle engagement force is adjusted as a function of the injection force or the pressure of the injection material, as the case may be, by way of a corresponding control device. In this manner, a constant equilibrium of engagement pressure and the opening force in the pressure is established, with selectable initial engagement tension. The energy consumption of the drive motor is reduced. With a special structural arrangement the complexity of the controls is substantially less.

Dependencies are inferred from the claim text.