Tham khảo tài liệu 'advanced vehicle technology episode 3 part 2', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | to its standard height. The ability for the spool valve to respond quickly and close off the exhaust valve is due to the right hand disc valve being open. Thus fluid in the unrestricted passage is permitted to push open the right hand disc valve this allows fluid to readily move through both the restricted and unrestricted passages from the right to left hand diaphragm chamber. Immediately the torsional wind-up of the control rod due to the antiroll bar rotation causes the spool valve to shift to the neutral cut-off position. Manual height correction A manual control lever is provided inside the car the lever being connected by actuating rods to the front and rear height correction units. Its purpose is to override the normal operation of the spool valve and to allow the driver to select five different positions Normal this is the standard operating position High or low two extreme positions Two positions intermediate between normal and high Hydropneumatic self-levelling spring unit Figs a and b and a b and c This constant height spring unit consists of two sections 1 a pneumatic spring and hydraulic damper system 2 a hydraulic constant level pump system. An approximately constant frequency of vibration for the sprung mass irrespective of load is obtained by having two gas springs a main gas spring in which the gas is contained behind a diaphragm and a correction gas reservoir spring Fig. a b and c . The main spring is controlled by displacing fluid from the upper piston chamber to the spring diaphragm chamber and the correction gas spring is operated by the lower piston chamber discharging fluid into the reservoir gas spring chamber. The whole spring unit resembles a telescopic damper. The cylindrical housing is attached to the sprung body structure whereas the piston and integral rod are anchored to either the unsprung suspension arm or axle. The housing unit comprises four coaxial cylinders 1 the central pump plunger cylinder with the .
