The heart of the PCV® technology is the oil flow between rod guide and piston. The bypasses thus creates control the oil flow to the bleeder valve, pre-valve, or main valve. In conjunction with various springs, valves and orifices, this results in numerous additional possibilities for the shock absorber setting. As a result, the damper characteristics can be even more precisely defined to match customer requirements and the vehicle’s field of application.
A significant increase in damping force at low damper velocities reduces rolling and pitching motions to a minimum. This increases the safety of drivers and passengers during braking and acceleration. At medium velocities, the PCV® with modified oil feed system provides a moderate increase in the damping force. The slope of the damper characteristic is flatter, which is perceived as a softer, more comfortable suspension response. To keep the vehicle uniformly stable and to prevent the vehicle body from rocking and vibrating, the damping force increases again with PCV® at higher piston speeds. High speed generate high damping forces via fluid friction, thus contributing to increased safety in vehicle operation.
The new sense of comfort provided by PCV® results from the robust damping of the axle movements at low compression speeds and from a very harmonic transition to the next force levels that are needed at higher speeds.
The PCV® can lay claim to yet another plus with regard to ride comfort: Thanks to the new valve geometry, the oil flow is smooth and calm in comparison to traditional twin-tube dampers. This allows ZF to minimize the hydraulic flow noises and the transmission of non-damper noises to adjacent components.