| 摘要 |
869,346. Adjusting vehicle body height; dashpots. DUNLOP RUBBER CO. Ltd. Oct. 21, 1957 [Oct. 27, 1956], No. 32824/56. Classes 108(2) and 108(3). In a height regulating valve for a vehicle suspension an arm 2, Figs. 1, 2 connected to an unsprung part of the vehicle turns a hub 14 when the wheels are deflected by road bumps. A hub 14 puts a helical spring 23, Fig. 2, under torsion which is transmitted to a plunger 40, Fig. 1, by one or other of ends 24, 25 of spring 23. Plunger 40 cannot move quickly under the action of the spring 23 as it is restrained by pistons 47, 54 which with an oil reservoir 29, a passage 30 and a restricted passage 31 form a double-acting dashpot. Air-space 37a above a flexible diaphragm 37 acts as a displacement chamber when the dashpot operates. When additional weight is added to the vehicle the springs are compressed and the arm 2 turns the hub 14 anticlockwise in Fig. 1, causing end 24 of the spring 23 to urge the plunger 40 to the right. A piston 54, urged by flange 43 will displace oil through the closed circuit formed by the passage 31, reservoir 29, passage 30 and the piston chamber. Plunger 40 pulls on a pin 69 which rocks an actuator 122 about knife edges 121 to open a compressed air inlet valve 80 by pressing on a valve-stem 81. Air under pressure is thus admitted to the pneumatic springs through an inlet 95, a non-return valve 87, inlet valve 80, passages 84, 72, chamber 28, passages 106, chamber 102 and outlet connector 103. This air raises the vehicle body and moves the arm 2 and plunger 40 in the reverse direction. Plunger 40 moves back to its mid-position undamped since oil can flow through an annular hole 53 of piston 54 when flange 43 moves away from piston 54. Inlet valve 80 is thus quickly closed when the predetermined body height is restored. If the vehicle load is reduced the springs expand and the arm 2 moves the plunger 40 to the left, piston 47 now pumping oil round the closed circuit. Head 70 of pin 69 opens exhaust-valve 112 by pushing on plunger 118 which lifts the valve off its seat. Air from the springs escapes through connector 103, valve 112 and passage 107 to the atmosphere. The spring height is thus reduced and the plunger 40 is allowed to return undamped to its mid-position by the arm 2, valve 112 closing when the predetermined body height is again restored. The time delay of the dashpot may be altered, by adjusting a restrictor valve 33 in passage 31, to prevent corrections to body height being made whilst the vehicle is cornering. The invention may be applied to both pneumatic and hydropneumatic suspension systems, but in both cases it will operate on the pneumatic chamber only. |
