Power plants – Reaction motor – With thrust direction modifying means
Reexamination Certificate
1999-02-25
2001-09-18
Freay, Charles G. (Department: 3746)
Power plants
Reaction motor
With thrust direction modifying means
Reexamination Certificate
active
06289669
ABSTRACT:
FIELD OF THE INVENTION
The invention relates to a lateral-thrust control arrangement, preferably for four-quadrant control of a missile. More particularly, the invention is directed to such an arrangement in which lateral thrust nozzles communicate with a solid-fuel gas generator via respective valves which are operated by a common actuator.
BACKGROUND AND PRIOR ART
Lateral-thrust nozzles fed by a solid-fuel gas generator, whose thrust is directed perpendicular to the longitudinal axis of the missile to be controlled, are known in the art.
Thus, for example, DE 3,901,041 shows a guided missile with a solid-fuel, hot-gas generator, whose hot gas passes through a multiple number of nozzles arranged regularly around the periphery of the missile and extending essentially perpendicularly to the longitudinal axis of the missile, and wherein the gas flow through the individual nozzles is controlled by means of a control device, which comprises a valve member for each nozzle, and a control star assigned to the valve members as an actuator, said control star having a number of arms corresponding to the number of nozzles, extending perpendicularly to the longitudinal axis of the missile, the control star being mounted so that it can be tilted all around the longitudinal axis of the missile, so that the nozzles can be controlled in a predetermined manner by a control device operated by means of electromagnets provided for each valve member in order to produce a lateral force to effect a change in the flight path of the missile.
When the control star is not actuated, the net effect of the thrusts of the lateral-thrust nozzles is canceled, and when the control stat is actuated, one predetermined lateral-thrust nozzle is supplied with hot gas, all the other nozzles being closed, so that the desired lateral force for the change in flight path is produced by the predetermined lateral-thrust nozzle.
The construction of the actuator as a control star permits only limited correcting movements for the valve members, which means only limited opening movements for the valve members, and in particular, only one opening of the controller lateral-thrust nozzle is produced via the original aperture dimension as a consequence of a rigid coupling of the valve members of all lateral-thrust nozzles due to the tiltably mounted control star when the lateral-thrust nozzles to be shut off are closed, so that a constant hot-gas outflow is produced through all of the lateral-thrust nozzles both in the rest position of the control star as well as in its operative positions, due to the resulting constant aperture cross-section.
Although only one component direction is required each time to produce the lateral-thrust function, in the known control device, the lateral-thrust nozzles for all component directions must be continuously actuatable in operation in order to maintain the total control system. Because of this, it is a disadvantage that the continuously high and uncontrolled combustion of the solid-fuel as well as the thus-prevailing total thrust capacity in relation to the usable or, in fact, to only the necessary lateral thrust, remains essentially unutilized, so that a correspondingly higher, mass and volume of propellant are necessary for the required lateral-thrust control operation.
In order to avoid this disadvantage, the use of a thrust control of a solid-fuel propellant engine might be possible with the use of a hybrid technique, in such a way that the combustion-chamber pressure and thus the thrust of a solid-fuel propellant engine can be controlled in a defined region and thus the propellant can be utilized more efficiently for the lateral-thrust control by mixing a co-supplied oxidator or one introduced from the outside into the unfavorably balanced combustible solid-fuel rocket engine.
In such a case, the total thrust capacity can be regulated, if it is necessary, for lateral-thrust control.
Apart from the fact that such a system requires a very complex mixing technology, based on the required mixing zone, a large structural volume is also necessary, which is out of proportion to the requirement of a missile lateral-thrust control.
It is known in fact from DE 1,291,206, that for the control of pitch, yaw and roll movements of a jet airplane during takeoff and landing, the gas flow in jet nozzles arranged in pairs relative to the pitch, yaw and roll axes can be controlled by means of hollow cylindrical thrusters actuated by motor operators, to supply the gas inlets of each nozzle pair synchronously.
In this way, a constant quantity of pressurized gas is distributed to the pair of nozzles without changing the percentage of the total gas quantity diverted from the power unit of the airplane, such that the necessary equilibrium state can be maintained during takeoff and landing.
However, such rotary valves regulating the gas flow in gas lines arranged in pairs and their control cannot be used in lateral-thrust control arrangements of the above described type.
SUMMARY OF THE INVENTION
An object of the invention is thus to provide a control system, which operates more effectively than those previously known without using a hybrid technique for regulating a solid-fuel propellant and which do not have the disadvantages of the known lateral-thrust control arrangements, particularly in the idling state.
This object is achieved by means of a novel lateral-thrust control arrangement for missiles of the above described type by use of the known phenomenon, that the rate of combustion of a solid-fuel propellant for producing gas is a function of the combustion-chamber pressure, can be used as a parameter for the construction of the control arrangement.
Proceeding from a lateral-thrust control arrangement of the type described earlier herein, the invention provides that the actuator can be adjustably controlled between an idle and a thrust position by rotating and axially displacing the actuator according to the required flight path, the actuator being configured such that the lateral-thrust nozzles can be controlled to be active or inactive individually, intermittently and independently of one another.
According to a preferred embodiment of the invention, the actuator is designed as a pressure-unloaded rotary directional control valve, preferably as a piston that can move longitudinally back and forth and rotatably and wherein at least one flow channel opening at the peripheral surface of the control valve can be selectively brought into fluid communication with the lateral-thrust nozzles.
According to another embodiment of the invention, the actuator is constructed as a truncated cone mounted for rotation and longitudinal reciprocal movement and having at least one control groove assigned to the valve members, the valve members and the actuator being arranged with their active axes lying perpendicular to one another.
The valve members are preferably constructed as seat valves held in a spring-loaded open position and guided linearly by means of a rolling element mounted on the free end of a valve rod.
The configuration of the lateral-thrust control arrangement according to the invention makes possible, for the first time, an idling mode, in which the combustion-chamber pressure and thus the rate of combustion of the solid-fuel of the gas generator is low, and a thrust mode, in which the combustion-chamber pressure is high and thrust can be produced intermittently by means of a lateral-thrust nozzle in any direction in a Cartesian coordinate system. Since the propellant is utilized essentially only for producing thrust in a selected direction in the Cartesian system and not also for maintaining a total-thrust capacity of the actuator, which heretofore had to be maintained for the continuous thrust feed for the lateral-thrust nozzles in all directions, its consumption is minimized, and the construction cost for the lateral-thrust control arrangement according to the invention is thus significantly reduced and the actuator arrangement is lighter in weight. In addition, the design of the lateral-thrust control ar
Freay Charles G.
Gartenberg Ehud
Ladas and Parry
LKF Lenkflugkörpersysteme GmbH
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