Missile With Highly Backswept Wing Unit, in Particular With Delta Wings

The invention relates to a missile with highly backswept wing unit, in particular with delta wings. Missiles of the aforementioned kind receive steering signals during target approach which through corresponding positioning devices bring about deflection movements of aerodynamically acting control surfaces.

Due to non-compensatable errors of the seeker head information, a stable approach is not possible, in particular when course corrections in conventional bank-to-turn methods become necessary.

Stable target approach can be achieved only if the course corrections are brought about by lateral force and lift control. For this purpose, lift surfaces in the plane containing the pitch and yaw axes of the missile are necessary in said missiles.

It is the object of the present invention to provide lift surfaces for lateral stabilization which become effective during target approach and bring about a given high increase of the lateral force. The lateral force surfaces, ie. stabilizers should have maximum extension and should not increase the air resistance of the missile during cruise and search flight. It is further an object of the invention to design the missile so that minimum dimensions are obtained for the missile container or silo receiver.

According to the invention, the problem posed is solved in that

(a) in addition to the aerodynamic, adjustable control surfaces, i.e. fixed fins, lateral force stabilizers are arranged on either side of the vertical longitudinal median plane encompassing the x-axis, i.e. roll axis, and in mirror symmetry relative to the horizontal longitudinal median plane encompassing the y-axis, i.e. pitch axis; that

(b) the lateral force stabilizers are arranged pivotable about axes in planes parallel to the vertical longitudinal median plane; and that

(c) to accommodate the lateral force stabilizers, storage spaces are formed within the wing contour in the region of the wing root and before the front spar of the wing.

Due to the design of the invention, lateral force stabilizers of large extension parallel to the flow direction and perpendicular to the wings can be used, the stabilizers creating no or very little air resistance during cruise and search flight in that they are stored in spaces within the wing structure.

The arrangement of lateral force stabilizers of large extension is achieved by utilizing the form of strongly backswept wings, in particular in the region of the wing root. As the lateral force stabilizers are rotated into their extended position only when needed, i.e. during target approach, any flight impairment due to increased air resistance, caused by the lateral force stabilizers, is avoided. By extending the lateral force stabilizers in pairs into vertical positions above and below the horizontal longitudinal median plane of the missile, no change in the lateral rolling moment is caused.

The pivot point about which the lateral force stabilizers are pivoted is arranged so that the weathercock stability of the missile is not altered by the extended lateral force stabilizers. Besides, the missile container may be given much smaller dimensions with respect to its height.

According to a further advantageous development of the invention, it is provided that for coupling the propeller, which is stationary in the container, with the running drive motor a friction clutch operable from the drive motor is provided.

By such a design it becomes possible to provide a missile container of minimum dimensions, the coupling between the drive motor and the standing propeller taking place, after the missile has left the container, automatically and without any further external application of force on the clutch.

Further features will become evident from the drawing and the description of examples.

Embodiments of the invention are illustrated in the drawing which are described more specifically below.

FIG. 1 shows in perspective, schematic representation a missile in which the lateral force stabilizer pairs are in extended position;

FIG. 1a, schematically and in perspective, the missile in connection with the container;

FIG. 2, in perspective and schematic representation, the design of the missile and wing structure;

FIG. 3, a partial transverse section along line III--III of FIG. 1 through a wing;

FIG. 4, in a section along line IV--IV of FIG. 3, details of the arrangement of the lateral force stabilizers;

FIG. 5, in a partial transverse section through the drive system, details of the propeller clutch in conjunction with the engine; and

FIG. 5a, in a detail from FIG. 5, details of the propeller clutch in operating position.

As shown in FIGS. 1 to 4, the missile as a whole is marked 1, the fuselage 2, and the nose section of the fuselage 3. The fuselage nose 3 serves to receive a target seeking device of known design.

Further, the rear section 4 of the fuselage 2 serves to receive the drive system for cruise flight, here consisting of a piston engine 7 for driving a propeller 6 and a gear unit. Inside the fuselage section 4 a launch rocket, not shown here, is also arranged for launching the missile 1 out of the container 1', 1".

In FIG. 1a are shown containers 1' and 1" which each serve to receive a missile for transport and launch. There may be any desired number of containers, stacked vertically or side by side, e.g. for accommodation on a motor vehicle.

Launching of the missile 1 from the container 1' or 1" is done by means of the aforementioned launch rocket, with the propeller 6 remaining stationary, but with the piston engine 7 already turned on. After missile 1 has left its container 1' or 1", the drive system 5 provides the propulsion.

In the embodiment shown, the wing unit of missile 1 consists of the delta wings 8. In the region of the wing tips of both wings 8, vertical stabilizers 10 with adjustable control rudders 11 are arranged. Further, ailerons 15, which also serve as elevators, are adjustably arranged at the rear edge of both wings, for missile control. Control of the missile 1 about its transverse or pitch axis y and about its longitudinal or roll axis x is brought about by superimposed control movements of the rudders 11 or respectively the rudders 11 and ailerons 15 in known manner.

In the region of the ailerons 15 or respectively in the region of both rudders 11, there are arranged for their actuation positioning units which consist in known manner of a drive motor coupled the rudders in conjunction with a positioning gear, a radio-controlled receiver, and a switching device. These control elements, which are known as to construction and mode of action, are not shown here, to simplify matters. For the lateral guidance of the missile 1 there are arranged, according to the invention, lateral force stabilizers 25, which are to be effective in particular in the final target approach phase of the flight mission.

In the embodiment shown, two pairs of such lateral force stabilizers 25a, 25b and 25c, 25d, respectively, are provided. With respect to their chord length t or respectively their span, the stabilizer pairs 25a, 25b and 25c, 25d, respectively, extend in planes lying on either side of the vertical longitudinal median plane E--E of the missile 1 and are parallel thereto, the stabilizers 25a, 25b and 25c, 25d of each pair occupying mirror-symmetrical positions with respect to the horizontal longitudinal median plane E'--E'. The upper and lower stabilizers 25a, 25c and 25b, 25d of the two pairs are equally spaced from the vertical longitudinal median plane E--E of missile 1. It is further provided to arrange the lateral force stabilizers 25 rotatably about axes 27, 27' which are parallel to the missile's transverse or pitch axis y, for retraction into storage spaces 26 inside the encompassing wing casing 28, in order, on the one hand, to avoid the production of additional resistance by the lateral force stabilizers during the cruising and searching phase of the missile and, on the other hand, to minimize the container dimensions. The lateral force stabilizers 25 of a pair are arranged so that in the retracted state the stabilizers are close together, lying side by side, so that the chord length t of the stabilizers 25 can be designed to have a magnitude in accordance with the thickness variation of the wings (FIGS. 3, 4). Conceivable also is a design where the stablizers 25 of a pair are arranged lying near the plane E--E and are to be retracted into corresponding spaces in the fuselage 2.

FIG. 2 shows the conventional design of the missile structure and in particular of the delta wings 8. The structure of the wings 8 contains spars and ribs, as well as stringers and the casing 28. In the embodiment shown, the front spar is marked 29; it extends at a relatively great distance from the front edge of the wing, with respect to the connection of the front edge 34 to the fuselage 2, transverse to the longitudinal or roll axis x of the missile. Joined with spar 29 are ribs 30 of the fuselage 2 and additional ribs 30 of the wings 8, in known manner. At a small lateral distance from the ribs 30, fixed rib portions 31 are connected to the front spar 29 on either side of the fuselage 2. Between the ribs 30 of the fuselage and ribs 31 of each wing 8 are formed the storage spaces 26 for the retracted lateral force stabilizers 25. The storage spaces 26 in the immediate vicinity of the fuselage 2 permit--in view of the dimensions of the delta wings, with respect to the profile thickness near the fuselage and the front edge 34 of the wings 8 extending relatively far from the front spar 29 toward the fuselage nose--a free space of relatively large dimensions. The extension and the chord length t of the lateral force stabilizers 25 are designed in accordance with these dimensions to achieve satisfactory stabilization. According to the design of FIGS. 1 to 3, the stabilizers 25a, 25b and 25c, 25d of each pair are arranged so that they overlap, lying side by side inside the storage spaces 26 (FIGS. 3, 4). The contour of the stabilizers conforms approximately with the cross-sectional contour of the wings 8 in the region of the wing root. The ribs 30, 31 receive the pivot pins (not shown) having axes 27, 27' (see FIG. 4) of the stabilizers 25. The stabilizers of a pair are pivoted in opposite directions from the retracted position into the extended position. To reduce the air resistance, covers for the slot type openings in the wing casing 28, through which the lateral force stabilizers surfaces 25 are passed, may be provided.

To deploy the stabilizers 25 into the extended position, there is provided according to FIG. 3 a release device 38, which contains an actuator 40 to be actuated by prestressed helical compression springs 39. The actuator 40 has cams 41 which act on the freely pivotable lateral force stabilizers 25 in the sense of a swinging-out movement. The respective lock release for the spring-loaded actuator 40 is designed in known manner and not shown here. The release can be effected by remote control.

According to FIG. 5, a clutch unit 50 is provided for coupling the engine 7 of the drive system 5 with the freely rotatable propeller 6. The assumption for the design is that, before launching, the missile 1 is securely in its container 1' or 1" and that the securement (not shown here) is released upon launching.

The clutch unit 50, which operates without supply of external energy, consists of a release device, a shifting device operating by means of centrifugal forces, and a friction clutch arranged between the freely rotatable propeller 6, 6' and the engine drive shaft 7'. The release device contains an axially adjustable shift pin 51 which is inserted in a central bore formed in the engine drive shaft 7' and which, when the missile 1 is in the fixed position the part of the container (not shown), thereby prestressing container 1' or 1", is held in a locking position by a helical compression spring 52. Further there are provided interlocking elements 53 which can be actuated in response to axial displacement of pin 51 by spring 52 and which serve to release a shift ring 54 which is urged axially by prestressed helical compression springs 56.

By means of the shift ring 54, centrifugal weights are provided in the form of jaws 59 freely movable in the radial direction relative to a support member 61 which jaws comprise friction surfaces 60 for making contact with counter-surfaces 60' mounted on the propeller hub 6'. The radially movable jaws 59 are fixed in their inoperative position by the shift ring 54, so that there can be no frictional engagement between the friction surfaces 60 and the hub 6' counter-surfaces 60'. The support member 61 is rigidly connected to a nut member 63 mounted concentrically on the engine drive shaft 7'. This nut member is threaded to screw onto a counter-thread (motion thread) of shaft 7' and is thus relatively adjustable in the direction of the longitudinal axis of shaft 7' or respectively in the direction of the axis of rotation of the propeller 6.

The friction clutch for transmission of the engine torque to propeller 6 is a clutch which comprises U-shaped clutch elements 64 arranged between the propeller hub 6' and the drive shaft 7'. The clutch element 64 is rigidly firmly connected to the nut member 63.

Further, an additional U-shaped clutch element 65 for providing frictional engagement between the drive shaft 7' and the propeller 6 is arranged between the nut member 63 on the drive shaft 7' and the propeller hub 6'. The clutch element 65 is operable, as is also the clutch element 64, by the relative axial displacement of the nut member 63 relative to shaft 7'.

As can be seen from FIG. 5a, the clutch elements 64, 65 are rings of U-shaped profile which lie axially side by side in an annular space formed between the bore of propeller hub 6' and the motor shaft 7' or the nut member 63, respectively. The web 66 is oriented to contact the bore surface of hub 6' for producing friction therebetween, and the lateral sections 67 are directed radially with respect to the longitudinal axis of the clutch. The rings further comprise cylindrical shoulder sections 67' which are connected in the axial direction of shaft 7'. Arranged between the lateral sections, 67 of clutch element 65 is an annular projection 68 integrally formed on shaft 7' and between the lateral branches 67 of clutch element 64 is an annular projection 69 integrally formed on the nut member 63.

The clutch unit functions as follows: In the course of preparation for the launching of the missile 1 from the container 1', the engine 7 is started. At this point the missile 1 is secured in container 1'. With the clutch unit 50 in the neutral position, the propeller 6 remains stationary during rotation of the drive shaft 7'. As the securement of missile 1 is released in container 1', and as a result of the launch movement of missile 1, e.g. with the aid of a launch rocket, the prestressed helical compression spring 52 displaces the shift pin 51 in the axial direction. The interlocking elements 53 thereby release the shift ring 54 for axial movement, and by action of the prestressed helical compression spring 56 the shift ring is moved in the axial direction. By means of this axial movement the revolving jaws 59 are released and displaced radially outward by centrifugal force. The surfaces 60 of the jaws 59 come in contact with the counter-surfaces 60' mounted on the propeller hub 6' and the resulting frictional engagement causes a relative rotation between the nut member 63 and the drive shaft 7'. Consequently, by means of the engagement of threads 70, 70', the nut member 63 is displaced axially relative to the drive shaft 7' and the clutch elements 65 establish a frictional engagement between propeller hub 6' and nut member 63 and hence also with shaft 7'. The nut member 63 is advanced in the axial direction until there is no longer any slip between drive shaft 7' and propeller hub 6'. With this axial movement of the nut member 63, the clutch elements 65 are also tensioned and establish direct frictional engagement between propeller hub 6' and drive shaft 7'.

Specifically the mode of operation of the clutch elements 64, 65 is such that an axial displacement of the nut member 63 by means of thread 70 or thread 70' of the drive shaft 7' simultaneously causes abutment of the lateral branches 67 of the rings 64, 65 against the annular projections 68, 69 and an arching of web 66. Thereby the frictional engagement between the bore surface of hub 6' and the drive shaft 7' or nut member 63 respectively is established.

Essentially the clutch-coupling process takes place after missile 1 has left its launch container 1'. The clutch unit 50 here makes possible an automatic activation of the coupling process between the stationary propeller 6 and the running engine 7. The process of clutch engagement takes place without the need for the supply of energy from the outside, by means of an externally initiated shift pulse.