Vickers, Inc.

Hpm Corporation

Procontrol Ag

Oskar Frech Gmbh & Co.

Ronald Siegrist

Bruno Stillhard

Bruno J Stillhard

Hugo Blochlinger

Norbert Erhard

Roland Fink

Herbert Noschilla

A pressing-in unit for a hot-chamber pressure diecasting machine permits an electro-mechanical drive for the casting plunger. In order to absorb the moments of inertia of the drive which occur during the switch-over of the casting plunger drive from the mold filling phase to the after-pressure phase, a spring element in the form of a plastic component or a liquid spring is inserted between the casting plunger and the pusher rod moved by the electric drive, which spring element is compressed by the additional path which the pusher rod still covers after the braking of the motor. The extent of the compression is selected such that the resulting axial force which is exercised by the plastic component or by the liquid spring is sufficient for causing the desired after-pressure in the molten metal.

Injection unit for a pressure die casting machine

An acceleration pressure is used as set value for the movement of the mass which is to be shifted, such as the mold clamping unit in an injection molding machine. For this purpose it is proposed to use preferably an electrically modulated pressure control valve for the pressure regulating device in the pressure drive system. Even with extremely short acceleration periods resonance oscillations are avoided, which until now prohibited the reduction of the acceleration period. With computing devices the movement of the mass can now be really controlled in relation to a selected velocity profile and/or a position profile or at least a part thereof.

Process and device for hydraulic drive of injection molding machines

A method is disclosed for controlling an injection molding machine of the type having an injection screw drivable for axial movement within an extrusion cylinder by a drive-controlled servo motor through a mechanical transmission, to provide a filling phase, a dwell phase, and a plasticization phase, the servo motor having a velocity command signal input connection, and the molding machine having sensors for screw position and injection pressure. The method includes the steps of presetting desired values for at least one of the injection pressure and the screw position; sensing the respective one of the corresponding actual injection pressure and actual screw position; and transmitting non-zero velocity command signals to the drive-controlled servo motor during at least the plasticization phase, and preferably also the filling and dwell phases, to move the injection screw within the cylinder. The velocity command signals are calculated as a function of a deviation of the respective one of the actual injection pressure and the actual screw position from the respective preset desired value, preferably using a linear functional relation during small deviation values, and a non-linear functional relation for large deviation values, to improve stability.

Process for injection molding machine with electric drives

Method and apparatus for controlling the nozzle engagement in an

A drive control apparatus for controlling a plurality of control variables of at least one electrically powered axle of a processing machine, such as an injection molding machine. Multivariable control means including internal signal processing and date storage means for an open and closed-loop control of phase angle, current input and velocity are dominating process computer means for a lag-free control of the control variables.

Injection molding machine with an electric drive

Device for hydraulic drive of injection molding machines

A hydrostatic or pneumatic drive for driving a mass to be accelerated and decelerated, such as in a die casting or injection moulding machine, has a controllable valve arrangement which is operable to vary the fluid flow rate therethrough. The fluid flow rate is controlled by a reference value control generator operable to produce a ramp having superimposed thereon further control pulses. Such control pulses are a positive control pulse at the beginning of the rising slope and at the end of the falling slope of the ramp and a negative control pulse at the end of the rising slope and at the beginning of the falling slope of the ramp. Each control pulse has a volume which corresponds to a so-called compression volume factor which reflects the compressibility of the fluid used in the drive and also of the elasticity of ducts which expand by fluid pressure.

Hydrostatic or pneumatic drive and method of operating same

Relief valve arrangement comprising a pressure limiting relief valve, the pressure setting thereof can be switched by an auxiliary piston between two or more ranges so that the control pressure, which is obtained by a pilot valve, can be within a region, which can be controlled accurately.

Growing community of inventors

Oberuzwil, Switzerland

Ronald Siegrist