GB999790A - Improvements in or relating to hydraulic suspension systems with automatic level corrector responsive to the vehicle load - Google Patents

Abstract

999,790. Vehicle suspensions. REGIE NATIONALE DES USINES RENAULT. Dec. 13, 1961 [Jan. 14, 1961], No. 44663/61. Heading B7D. A suspension system for a vehicle comprises hydraulic supporting cylinders at each wheel and a pump continuously supplying pressure fluid, there being means operable by the driver or automatically in response to operation conditions for connecting the pump to each cylinder so as to raise the vehicle, for connecting the cylinder to reservoir for lowering the vehicle and for holding the liquid in the reservoir, the actuation of this means being dependent upon the diminished pressure prevailing in the engine induction system. A fluid pump, not shown, delivers fluid from a reservoir 6, Fig. 1, into a distributing valve 1 through a port 7 and through spaces 8 and 14 and the grooved centre of a piston 3 to a port 15 and thence to the hydraulic wheel suspension cylinder. The valve 1 has passages 9 and 10 returning to the reservoir 6 and closed by a valve 4 attached to the piston 3. A flexible member 12<1> gripped between the valve 4 and a cylindrical member 11 acted upon by a spring 13, separates into two parts a cover member 12 which contains a one-way valve 21 which can be unseated by a rod 25 attached to the piston 3. A pipe 16 is connected to the chamber 12 and to the engine induction manifold 17 through a one-way valve 18 and also to a pipe 19 leading to atmosphere and controlled by a valve 20. A pipe 23 leads to atmosphere through the one-way valve 21 and a valve 24. The valves 20 and 24 may be incorporated in a device, Fig. 3, wherein the line 19 is connected with a passage 31, the line 23 with a passage 30, and a passage 35 connects a chamber 16 to atmosphere, the chamber 16 being provided with a disc 32 having arcuate slots through which, at different positions of the disc, a connection may be established between the passages 30 and 31 and the chamber 16. The disc 32 is rotatable by a member 33 operatively connected to the vehicle suspension system. On heavy loading, the valves 20 and 24 are open to atmosphere, so that the piston 3 is held by the spring 13 in the position shown and the wheel suspension cylinder is supplied with liquid. With diminished loading, the arm 33 is rotated to a position where both valves 20 and 24 are closed and the wheel suspension cylinder is opened to reservoir by movement of the valve 4 to the left of the position shown. In an intermediate position, the valve 24 is opened and the valve 20 is closed and the piston 3 closes the passage 14 holding the liquid in the wheel cylinder. In this position of the valves continued movement of the piston 3 to the left causes unseating of the one-way valve 21 through the bar 25. A device for manually controlling the apparatus may be inserted in the mechanism, as shown in Fig. 7, where the lines 60<1> and 611 correspond to the lines 19 and 23 and lead to a manually operable distributing valve 64 having output lines 60<1>, 61<1> and 62<1> leading to a three-way valve device, Fig. 8, corresponding to the device of Fig. 3, whereby the valves 20 and 24 may be separately or simultaneously opened manually or automatically in dependence upon theconnection with the suspension system. A distributing valve for operating with tandem axles, Fig. 6, comprising twin chambers 49 and 50 connected to the engine induction manifold and operating pistons 46 and 47, the fluid supplied from the pump being conducted through the passages 51, grooves 52 and lines 53 to the suspension cylinders. Upon movement of the pistons 46 and 47, corresponding to similar movements of the apparatus of Fig. 1, the wheel cylinders may discharge to reservoir through the grooves 54 and passage 48. Sliding members 55 and 551 are contained within the pistons 46 and 47 and are connected together at 56. The member 55 is pinned at 59 to the piston 47, but by appropriate relative motion, the passage 58 of piston 46 can be opened to discharge to reservoir through the centre of member 55. A modification for use with an electric levelling device comprises a switch unit, Fig. 5, similarly connected to the induction manifold, and having operating switches 44 and 45.