Hydraulic tensioning device e.g. for programmable machine tool

摘要

The pump (10) draws hydraulic fluid from a container and passes it along the supply line (12) to the electrohydraulic switch (13) for the setting unit (14) of the pressure regulating valve (15), subject to the pre-control valve (56). The control slide (17) controls the outlet (19) and line (20) to the 4/3 way valve (21) and to the left-hand space (28) of the double-acting cylinder (29), with setting piston (30). The right-hand space is connected to the line (25) and the way valve is preferably electrically actuated. The force in the collect chuck (43) is detected by a force sensor (35) coupled with the connecting rod (33) of the setting piston.