
Hydraulic Compression Stop (HCS) for end of compression stroke energy management
Hydraulic Compression Stop is an hydraulic system which replaces conventional hard bump stops with hydraulic cushion. The peak force transmitted to the vehicle body from the suspension can be reduced because energy will be dissipated as HCS damping. Because of this, the vehicle body structure can be lighter due to lower strength and stiffness requirements for the same standard of refinement and durability. Moreover, HCS is not only more tuneable than traditional bump stops, leading to better vehicle dynamic performance, but it also improves noise, vibration and harshness (NVH). HCS improves occupant comfort and chassis refinement while ensuring that a heavily laden vehicle that is more likely to bottom its suspension can do so without transmitting damaging loads into the body structure.
HCS features:
- Reduces the maximum compression forces in the suspension during extreme events or vehicle overload
- Dissipates peak of energy which is accumulated in jounce bumper by shock absorber
- Provides progressive and smooth increase of end-of-travel load
- Improves NVH
- Rapidly recovers damping function between events
- HCS damping force value depends on the damper position (system is activated when required position is reached) and velocity
Due to different expectations to the level of compression damping force increase in the HCS system, two solutions are available:

Hydraulic Compression Stop Low Damping (HCS LD)
Maximum compression damping generated by the system is limited by damper tuning due to hydraulic balance – additional compression damping is produced by additional HCS piston valve while utilizing the standard base valve.
System launched into the market in 2018.


Hydraulic Compression Stop High Damping (HCS HD)
Maximum compression damping forces are not limited by damper tuning – additional damping is generated in a separate chamber.
