| General Details | Description | Operation | Circuit layout | Height correction | Identification of parts | I - GENERAL DETAILSTwo fluids permit the functioning of the hydropneumatic suspension : a liquid and a gas.
II - DESCRIPTION
|
IV - CIRCUIT LAYOUT |
V - HEIGHT CORRECTOR |
|
|||
1) | The Height Corrector :
|
|
OPERATION OF THE HEIGHT CORRECTOR
(Diagrams) |
|
Slide-valve moves from |
Slide-valve moves from |
Slide-valve moves from |
Slide-valve moves from |
2) | Automatic Height Control :
Let us examine the front control : The ball end on the Height Corrector slide-valve is acted upon by a " U "-shaped lever brazed on to a torsion control rod. The control rod is clamped to the centre of the anti-roll bar. The anti-roll bar is located by two bushes, the pre-loading of which is adjustable by means of spacers. Also two clamps are provided to adjust its end-float. At the rear the control system is similar, only the anti-roll bar is different. Operation of the Controls : As the anti-roll bar is connected to the suspension arms of both wheels, any movement of the latter will cause the anti-roll bar to rotate. When the chassis is at its normal running height, the angular position of the Height Corrector control rod is adjusted so that it has no effect at all on the slide-valve of the Height Corrector, thus it remains in its "cut-off" position. To understand the working of the Height Correction system, let us take the simple example of a change in the static load. An increase in the load causes a movement of the chassis and thus a rotation of the anti-roll bar. This movement is transmitted to the Height Corrector control rod which is therefore twisted, and puts a continuous load on the Height Corrector Control Rod. The slide-valve is therefore pushed in to the "inlet " position. Now the amount of fluid between the diaphragm and the piston is increased and the chassis rises. This movement reverses the movement of the anti-roll bar. The load imposed on the slide-valve by the control rod ceases ant it returns to the "cut-off " position. 'The return to the "cut-off" position is rapid, because the slide-valve does not offer any resistance in this direction. The chassis returns to its normal height again. If the static load is decreased the operations are similar, but the directions of movement are reversed. Let us now take an example of a dynamic change of load.
|
3) |
Manual Height Control :
A manual control is provided to override the normal operation of the slide valves and allows the driver to select 5 different positions.
Operation. The explanation is given showing the rear Height Corrector, but applies equally to the front. Selection of an intermediate position from " Normal". The movement of the manual control lever from the " Normal " position to one of the two intermediate positions moves the rear linkage rod (1). 'As this rod moves it acts upon the torsion rod (2) which is located in two brackets fixed to the chassis. The rod (3), the lever (4) and consequently the slide valve are moved towards the front. The suspension cylinders are connected to the source of high pressure. The amount of fluid in the rear suspension units is increased. The car "rises". This "rise " causes the anti-roll bar to rotate, which transmits its movement to the Height Corrector control rod (5) which twists and exerts a continuous pull on the Height Corrector slide-valve, this pull opposes the action of the manual height control. When the load exerted by the control rod (5) becomes equal to the load exerted by the torsion rod (2), the slide-valve is no longer held in and returns to its "cut-off" position. The suspension cylinders are cut-off from the source of pressure and from the "exhaust" position, the car stabilises. The pressure existing in the suspension cylinders is the same as when the car is in the "Normal" position, only the volume of fluid has changed. Selection of " High" or "Low" from "Normal". The movement of the manual control lever to one or other of these positions exerts a load on the Height Corrector slide-valve by way of the rods and levers, so that the valve is held in the "Inlet" or " Exhaust" positions. The volume of fluid increases or decreases accordingly. The vehicle rises or falls. These movements of the car cause opposite movements of the anti-roll bar which try to cancel the effect of the initial load acting on the Height Corrector slide-valve by the control rod (5). Equilibrium cannot be established because the load created by the control rod (5) is always less than that created by the torsion rod (2). The Height Corrector slide-valve is held in the "Inlet" or "Exhaust" positions. The pressure in the suspension cylinders is either maximum or nil. The chassis rests against the rubber limit stops. |
4) |
Distribution and Isolation of Pressure :
|
VI - IDENTIFICATION OF PARTS |
1) |
Suspension Spheres : All the suspension spheres are of exactly the same size. The numbers stamped on the heads of the filler screws enable the spheres to be easily identified. (The numbers correspond to the initial inflation pressure).
|
2) |
Suspension Spheres : Three types of cylinders :
|
3) |
Dampers :
|
4) |
Height Correctors :
|
5) |
Pressure Distributor Blocks :
two types :
|