Arrangement for steering-power limitation in hydraulic servo-steering systems
AssigneeLangen & Co.
InventorGunter Strauff
Life of this patent
Estimating the term…
Abstract
An arrangement for limiting the steering-power in hydraulic servo-steering systems provided with a valve of the type of a three-way three positions valve for controlling a pressure flow from a pressure source to a working space of a preferably higher effective area of a servo-motor or from the working space to a return flow, in which the working space of a preferably lesser effective area is always connected with the pressure source, and the reaction areas with hydraulic reaction areas serve for signalling back a steering sensation to the steering wheel, which reaction areas are arranged to the various effective areas of the servo-motor, and, in combination with respective lever arms, etc., and/or respective reaction areas define a torque dynamometer, etc.
Claims5
An arrangement for limiting the steering power in hydraulic servo-steering systems for vehicles having steerable wheels and
- a steering wheel,
- a servo-motor (4) having
- a cylinder (24),
- a piston (26) and
- a piston rod (25) defining larger (28) and smaller (27) working areas, the smaller working area (27) being continuously connected with a pressure source (1),
- the servo-motor (4) being operatively connected with the steerable wheels,
- a comparator means (3, 3o) being operatively connected with the steering wheel and provided for the relay of a steering sensation to the steering wheel,
- the comparator means (3, 3o) including an activator means (33, 34;
- 11),
- a first reaction chamber (17) of a larger effective reaction area (F.sub.2) and
- a second reaction chamber (42) of a smaller effective reaction area (F.sub.1) continuously connected with the pressure source (1) and
- a three way, three position control valve portion (7, 31) controlling a pressure medium flow from the pressure source (1) to the larger working area (28) of the servomotor (4) or from said larger working area (28) to a return flow (T.sub.1, 16),
- said larger working area (28) of the servo-motor (4) being connected by a restrictor (19) with the first reaction chamber (17),
- the smaller working area (27) of the servo-motor (4) 41 and the pressure source (1) being connected with the first reaction chamber (17) by a pressure release valve (23),
- said pressure release valve (23) opening during the reduction of a predetermined lower pressure in the first reaction chamber (17) or during the exceeding of a predetermined pressure difference between the smaller working area (27) and the first reaction chamber (17),
- and the first reaction chamber (17) being connected with 51 and exhaust passage via a pressure limitation valve (21), with said pressure limitation valve (21) preventing the exceeding of a predetermined upper pressure of the first reaction chamber (17).
Dependencies are inferred from the claim text.