Abstract: A plasticizing unit of an injection molding machine for micro-injection molding includes a plasticizing cylinder and a screw, which conveys material to be plasticized from a feed opening in the direction of an outlet opening. At least one longitudinal section of the plasticizing cylinder between the feed opening and the outlet opening is formed as a transition region in which the inner diameter of the plasticizing cylinder tapers in the direction of the outlet opening to the outer diameter of the screw. The transition region is formed by a sleeve-shaped transition element which is removably and replaceably mounted within the plasticizing cylinder. The plasticizing cylinder is designed as at least two parts for removing and replacing the sleeve-shaped transition element.

Abstract: A control system for injection molding machines comprises a memory means (16) for storing set values. Further, a signal input for the transmission of actual values to the control system is provided. A first control means (18) is used for the transmission of a control field with consideration to previous values. A second control means (20) is provided for the transmission of a correction value, in particular with consideration to a deviation of the actual value from the set value. A correlation means (22) serves to correlate the control field values with the correction value for outputting a control variable.

Abstract: A mold closing device for injection molding machines, especially injection molding machines for plastic material, comprises two mold closing plates (10, 12) movable relative to each other. A displacing means (22) with an electromotive drive (26) is provided for opening and closing the mold closing plates (10, 12). According to the invention, the electromotive displacing means (22) that allows for a quick and positionally accurate opening and closing, is connected to a hydraulic holding means (24) for generating a holding force.

Abstract: A control system for injection molding machines comprises a central control unit (26) for executing cyclical machine program sequences. Further, a visualization means (24, 25) is connected with the central control unit (26). The central control unit (26) has connected therewith, via an input/output means (16), an injection molding machine (18). According to the invention, an additional control unit (28) for cycle-independent processing of time-critical control steps is arranged independently of the central control unit (26) and is adapted for reducing the error-proneness. The additional control unit (28) is in particular an FPGA control unit.

Abstract: The injection moulding machine has a plasticizing cylinder, arranged in whose interior there is a worm with an axial through-hole. The interior of the plasticizing cylinder is connected to a nozzle opening via a cylinder chamber. Operating in the cylinder chamber is a needle which extends through the through-hole in the worm and has a smaller diameter than the cylinder chamber. The tip of the worm constitutes, together with a correspondingly shaped sealing seat, a reverse flow barrier during the injection process. After the end of the injection process the worm is rotated and conveys plasticized plastic material in the direction towards the nozzle opening. As a result of the rising pressure in the worm threads the worm is pushed back and the plasticized material can penetrate into the annular space between the needle and the cylinder chamber. When the worm is rotated further, a pressure is also created in the annular space which slides the needle back into its starting position.

Abstract: The drive includes a reversible variable output pump (1), which supplies a hydraulic working machine (6) and is driven by an asynchronous motor (2). The working machine is intermittently hydraulically pressurized. During these times the asynchronous motor can be switched off since the subsequent start-up process, which causes a high current consumption in the case of asynchronous motors, is effected by the variable output pump. Before the beginning of the start-up process the variable output pump is preset to the maximum negative discharge rate by its proportional valve (10) being acted on by a control pressure. The volume pressurized in the working machine is then applied to the output side of the variable output pump. The asynchronous motor is connected to the current supply network after reaching a minimum speed.

Abstract: A method is disclosed of operating an injection molding machine including a hydraulic device (1) which has an asynchronous main drive motor (10) driving a hydraulic pump (2). The injection molding machine is operated in an injection molding cycle with a cooling phase and a phase in which an injection molding tool is opened following the cooling phase. It is determined before commencement of the injection molding cycle if the duration of the cooling phase is above a minimum duration. If the duration of the cooling phase is above the minimum duration the asynchronous main drive motor (10) is switched off after or at commencement of the cooling phase and is switched on again before commencement of the phase in which the injection molding tool is opened. Electrical energy is saved by switching off the main drive motor in dependence on the cycle.

Abstract: The hydraulic mould closure device for an injection moulding machine has a pressure convertor, whose high pressure piston extends into a passage leading to the pressure side of the closure piston and closes it, when producing the closure pressure. Formed in the low pressure piston is an actuating cylinder into which an actuating piston extends. The actuating piston is connectable to the hydraulic tank and to the hydraulic pump. Adjacent to the low pressure cylinder of the pressure convertor there is a space whose diameter is larger than that of the low pressure cylinder. The actuating piston also has lateral openings which move out of the actuating cylinder as soon as the high pressure piston moves into the high pressure cylinder. The piston element of the pressure convertor is moved very rapidly out of the rest position into its active position so that operation occurs with reduced control times.

Abstract: The control unit has a screen which is flanked on both sides by function key sets for controlling the functional sequence of the machine. A keyboard for inputting data into the processor of the control unit is arranged on a pivotal flap. The latter is so mounted about a horizontal axis below the screen that, in the unused state of the keyboard, it may be swung onto the screen and protectively covers the latter, at least in the lower region. A second pivotal flap is pivotably mounted in the upper region of the control unit above the screen and can be folded down for protecting the upper region of the screen. The second pivotal flap can furthermore be used for anti-dazzle protection for partially shading the screen from undesired dazzling light.

Abstract: A hydraulic actuating and locking device includes a locking piston within a cylinder, an actuating piston within a cylinder in the rear surface of the locking piston and a pressure multiplier connected to the space behind the piston. A passage, constituting a high pressure cylinder, connects the space behind the piston to an oil reservoir and is adapted to receive and be sealed by the high pressure piston of the pressure multiplier.