Patent ID: 6872066

Claim:
An injection molding machine with a vertically displaceable closing unit, comprising: a plate-like lower yoke as a counterpressure plate; a plate-like upper yoke as a stationary mold clamping plate; at least three vertically aligned struts connecting the lower yoke and the upper yoke with each other in their marginal zones in a force-locked manner; another plate-like element serving as a displaceable mold clamping plate, said another plate-like element being displaceable on the struts; one or more driving cylinders for displacing said displaceable mold clamping plate, said cylinders being connected to said displaceable mold clamping plate and the counterpressure plate, in a manner such that single- or multi-component molding tool halves arranged on surfaces of the mold clamping plates facing each other are driven from a maximum spacing into a position of mutual abutment, and vice-versa; and a piston-cylinder system acting between the counterpressure plate and the displaceable mold clamping plate for generating a required closing pressure; wherein the piston-cylinder system is acted upon by a fluid medium, said piston-cylinder system, in an abutting position, being retractable and extendable in a horizontal direction from an external space of a closing unit ( 3 ) between the counterpressure plate ( 4 ) and the displaceable mold clamping plate ( 5 ), and wherein the piston-cylinder system is adapted to be filled with or drained with the fluid medium to create a stroke volume, and wherein the system is adapted to receive different amounts of the fluid medium at different time intervals as a pre-tensioning volume for generating the closing pressure so as to be able to adapt a starting height of the piston-cylinder system ( 2 ) to different heights of the molding tool and wherein a lower bottom surface ( 25 ) of the piston-cylinder system ( 2 ) facing the counterpressure plate ( 4 ) is directly displaced on the counterpressure plate ( 4 ) and a support plate ( 12 ) extending an upper cover surface ( 11 ) of said counterpressure plate and wherein a lower bottom surface ( 25 ) of the piston-cylinder system ( 2 ) facing the counterpressure plate ( 4 ) is displaced on the counterpressure plate ( 4 ) and support plate ( 12 ) by means of wheel or roller elements ( 22 , 23 ) mounted on the piston-cylinder system or in or on the counterpressure plate ( 4 ) and support plate ( 12 ), wherein the wheel- or roller elements ( 22 , 23 ) each are supported so that the piston-cylinder system ( 2 ) is positioned on the counterpressure plate ( 4 ) in its working position between the counterpressure plate ( 4 ) and the displaceable mold clamping plate ( 5 ).