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AssigneeDeutsche Forschungs- und Versuchsanstalt fur Luft- u. Raumfahrt
InventorsReiner Onken, Gunter Mansfeld, Johannes Tersteegen
Estimating the term…
An electro-hydraulic actuator is disclosed, particularly for use with control surfaces in aircraft. The actuator includes a regulating piston and cylinders an rapidly-operable switching valves for the positioning of the piston in the cylinder that are operated by the supplying of discrete volumes of operating fluid thereto. Switching pulses are applied to the valves by a computer, and a sensor that is responsive to each activation of the switching valves applies an answering pulse to the computer wherein a valve breakdown can immediately be recognized. The sensor may be responsive to changes in pressure and/or flow between the valves and the cylinder located at the valve body.
An electro-hydraulic actuator for use in the control of surfaces in aircraft, comprising a hydraulic regulating cylinder having a piston located intermediate therein to define separate chambers, said piston being bilaterally loaded and disposed in a predetermined adjusted position and being operatively interconnected to a surface for the control thereof, two bistable controlled ball valves communicating with said cylinder and through which predetermined discrete amounts of hydraulic fluid of an hydraulic system are directed for flow into a preselected chamber of said cylinder for effecting the control of said piston, a process computer, valve control means operatively interconnected to said ball valves and electrically communicating with said process computer, and sensor means located between said ball valves and said cylinder and being electrically interconnected to said process computer, said valve control means being responsive to said process computer and receiving switching pulses therefrom for moving said ball valves to an open or closed position and said sensor means being responsive to a variation in the position of said piston to detect a differential condition between said ball valves and said cylinder and delivering electrical signals to said process computer to confirm that the ball valves have operated in accordance with the switching pulses received by said valve control means from said process computer.
Dependencies are inferred from the claim text.
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No related US applications are recorded in the indexed filing history.
Using electrical energy: using electro-hydrostatic actuators [EHA's]
Aeroplanes
Term ended 30 May 1999 (estimated)
USPTO file history isn’t available for this patent, so only indexed dates are shown.
The invention relates to an electro-hydraulic actuator and to a fast-switching magnetic valve for use therein, and has use particularly with control surfaces in aircraft.
By means of an electro-hydraulic actuator, it is possible to control movable surfaces of relatively high power level in aircraft, for example aircraft rudders, by electrical signals. In order to achieve the degree of safety necessary in aircraft, high demands are made for reliability in the actuator, in particular for the reliable recognition of breakdowns.
In the prior known actuators in aircraft, designed as servo circuits, the critical elements in relation to the reliability are the means for the provision of feed back and the servo valve. Owing to the analogue processing of signals, the recognition of breakdown presents difficulties. Also, with known actuators which operate with pilot valves in place of servo valves, the provision of feed back has been retained in such devices proposed up to the present time.
In the drawings which illustrate the best mode presently contemplated for carrying out the present invention:
FIG. 1 is a diagrammatic illustration of an airplane steering and control system embodied in the present invention in which an electro-hydraulic actuator device is employed, having a servo unit for use with a rudder setting device, and being free from feed back;
FIG. 2 is a diagrammatic illustration of a first embodiment of the actuator device embodied herein that is free from feed back;
The control system as shown in FIG. 1 includes a process computer of conventional design acting as automatic pilot to which the pilot command 4 is introduced as the required value. In addition, the flight position quantities 6, determined in the usual way, are transmitted to the process computer 2.
The actuating device, with recognition of breakdown, designed according to the invention is included in the block illustrated in phantom and indicated at 8. The actuating device 8 includes electro-hydraulic switch valves 10 which are activated by the process computer 2 through electrical leads 12, 14. The switch valves 10 are connected to a suitable hydraulic system, not illustrated in FIG. 1.
The volume of oil measured by the valves 10 is fed through a conduit 16 to a regulating cylinder 18. A sensor 24, dependent on pressure and/or flow, is connected to the conduit 16 by a conduit 22, where, at each activation, the sensor 24 emits an electrical signal which is fed back to the process computer 2 through a signal connection 26. In the process computer 2 the signals emitted by the sensor 24 are compared with the electrical switch pulses of the switch valves 10, in such a way that breakdowns, for example, failure of a switch valve to switch over, are immediately recognizable. A rudder setter 28 is controlled by the proportionally operating actuating device, and for its part, activates the rudder, not illustrated in FIG. 1.