Pre-controlled pressure reduction valve - has main control piston with two control edges for connection of low pressure side to pre-control valve and damping arrangement

摘要

The two-way valve has standardised connection system for high and low pressure, also including the control oil terminal for draining control oil from a pre-control valve, as well as a dampening device for a hollow main control piston (2). The latter has two control edges (2a, 2b), the second one (2b) providing a connection at the main piston stroke of the low pressure side (N) to the control chamber (12) of the main piston. The connection is provided beyond the closing position of the main piston. The control chamber is connected to the valve chamber (24) of the pre-control valve. The dampening device consists of a piston chamber (17), cooperating with a piston (13), the piston chamber being connected outwards by a throttle (15). The piston chamber forming part (2d), or the damping piston, form fixed components of the main control piston. The latter first control edge (2a) cooperates with progressively variable connecting bores (8a) between the high and low pressure sides in such a manner that the opening cross section is progressively reduced with the main piston increasing stroke.