CDC full name of the Continuous Damping Control, which means continuous damping control systems, Buick called full-time active hydraulic damping system stability, but this technology is not universal chassis developed its own technology, but from Germany the well-known manufacturer ZF Sachs, the company is the well-known wholly owned subsidiary of ZF driveline and chassis technology companies in Germany, the new BMW 7 Series uses 8-speed automatic transmission comes from ZF. ZF Sachs and ZF’s also been a century of history (since 1895), the main production powertrain, the clutch and shock absorber products, it set up a branch in Shanghai, China and set up three wholly owned and joint ventures, production the torque converter, the shock absorber parts, clutches, and other products.
Now we come to understand how the CDC system:
the core
As shown in FIG, CDC system member by the central control unit, CDC shock absorbers, vehicle body acceleration sensor, an acceleration sensor and a wheel CDC control valves, wherein the hydraulic damper is based on a conventional damper structure, marked with the damper fluid, internal and external two chambers, the oil can flow through the pores of the link between the two chambers, when the wheel bumps, the shock absorber piston will move up and down within the sleeve, it will reciprocate in the oil chamber of the piston reciprocating motion under the action of the flow between the two chambers. Fluid friction between the hole wall and the friction between the oil molecules resistance to movement of the piston, the vibration kinetic energy into heat, which is released into the air through the damper housing, thus achieving the damper the “shock absorption” process, the system is an issue in the CDC, “pores”, between the two chambers through the valve electronically controlled to vary the cross sectional area of the communication portion, when a certain flow rate, the fluid resistance is the size of the cross-sectional area inversely, thus changing the resistance between the fluid chamber reciprocates, thereby affecting a change to the shock absorber damping.
CDC system accelerometer sensor, a wheel acceleration sensor, lateral acceleration sensor data and vehicle running state determination according to the vehicle body, the central control unit calculates the ECU, then the ECU damper of the CDC corresponding instruction issue control valve, the control valve opening adapted to provide a current statusThe damping.
In actual driving, CDC in the face bumpy roads can greatly weaken the rebound and spring shock from the road surface, so that the body remains stable in terms of the theory of the state, CDC able to do strenuous wheel up and down jitter when the body only as a general sea of sailing up and down. In the intense driving time and can improve the suspension damping to provide adequate support, and more responsive chassis to improve handling of the vehicle. ZF Sachs is also mentioned in the introduction of the CDC, the CDC using the system of the vehicle than the vehicle without the system has a shorter braking distance. The CDC’s application is not limited to cars, ZF Sachs has CDC system products for large passenger cars, trucks and other commercial vehicles, for passenger comfort and safety of goods have provided better protection.
Data show, ZF Sachs CDC reading system for a car in the vehicle driving data can be 1 millisecond, and the completion of the damper in the same short period of time regulation. That is, in theory, the operating frequency of the system up to 1000 times per second.