Aeronautics and spacecraft with an aeronautics connection with a separation mechanism and method for controlled separation of aeronautics and space craft

Abstract

The present invention relates to an aerospace device (10) with a propulsion stage connection comprising a first lower propulsion stage (11) and at least one second, upper propulsion stage (12) connected to the first, wherein the propulsion stage connection has a passive separation mechanism (13) with a controllably detachable connecting element (14) and wherein the connecting element (14) is arranged on the circumference of mutually facing end regions (16a, b) of the propulsion stages (11, 12) and is held by a circumferential clamping element (15) and the clamping element (15) has at least one form-fit and force-fit structural connection and / or predetermined breaking point (26) that fails under defined overload, and a method for controlled separation of a propulsion stage connection of an aerospace device (10).

Description

TECHNICAL AREA OF INVENTION

[0001] The present invention relates to an aerospace device with a propulsion stage connection and a method for controlled separation of propulsion stages of an aerospace device. BACKGROUND OF THE INVENTION

[0002] Aerospace vehicles, such as rockets or launch vehicles, typically have multiple propulsion stages that are ignited sequentially to generate thrust and acceleration. Before the next stage ignites, the previously spent stage must usually be separated. Active stage separation mechanisms are known for this purpose. These mechanisms use pyrotechnic elements to cause a controlled explosion of the components connecting the propulsion stages, such as clamping rings, to detach them from the unit. The propulsion stages then separate completely due to the axial thrust generated by the next stage or by auxiliary thrusters attached to the stages.Active separation mechanisms, such as the pyrotechnic elements described above, increase the complexity of the control system, the weight and the cost of the aerospace equipment. SUMMARY OF THE INVENTION

[0003] Accordingly, it is an object of the present invention to provide a means for the safe and cost-effective separation of missile stages.

[0004] The present problem is solved by an aerospace device with a propulsion stage connection having the features of claim 1 and by a method for controlled separation of a propulsion stage connection of an aerospace device having the features of claim 10.

[0005] According to a first aspect of the present invention, an aerospace device is provided with a drive stage connection featuring a passive release mechanism. This connection comprises a first lower drive stage and at least one second, upper drive stage connected to the first, wherein the release mechanism includes at least one controllably detachable connecting element. The connecting element is arranged on the circumference of mutually facing end regions of the drive stages and is held by a circumferential clamping element. The clamping element has at least one form-fit or force-fit structural connection and / or a predetermined breaking point that fails under a defined overload. A pin or plug connection connecting the ends of the clamping element can be considered, for example, as a material-fit or force-fit structural connection.

[0006] According to another aspect of the present invention, a method for the controlled separation of a drive stage connection in an aerospace device according to the invention is provided.

[0007] The present invention aims to enable a passive and purely mechanical controlled separation of the propulsion stages of an aerospace aircraft without the use of additional active separation triggers, such as pyrotechnic or electronically controlled release mechanisms, in the propulsion stage connection or any connecting element provided therein. According to the invention, the separation is achieved mechanically by utilizing the pressure of the gas mass flow generated when a pyrotechnic gas source is ignited in the engine of the continuing, i.e., preferably upper, propulsion stage of the aerospace aircraft. The gas pressure is used by means of pressure control within the propulsion stage to induce structural failure of the clamping element and the subsequent separation of the connecting elements.The elimination of active release mechanisms is particularly advantageous because the separation of the drive stages occurs passively, and a safe and controlled separation of the drive stages is ensured through appropriate design of the connecting and clamping device. At the same time, the separation mechanism should be designed to be cost-effective.

[0008] According to one embodiment of the aerospace device, the connecting element is designed as a segmented clamping ring, preferably comprising two or more clamping ring segments. These clamping ring segments are arranged on the circumference of the mutually facing end regions of the drive stages and overlap, at least partially, radial projections of the end regions. This advantageously achieves a mechanical connection between the drive stages.

[0009] According to one embodiment, the overlapping radial projections can be designed as chamfered shoulder flanks with guide surfaces on the circumference of the end regions, and the clamping ring segments can have a geometry that advantageously allows a positive locking contact with the guide surfaces in the assembled, i.e., not activated, state of the separation mechanism.

[0010] According to one embodiment, the clamping ring segments are connected or connectable via material-locking or force-locking structural connections that fail under a defined overload. These material-locking or force-locking structural connections are, for example, designed as pin or plug connections between the clamping ring segments. These advantageously support the positioning of the connecting element during assembly of the release mechanism and before its activation, and are also destroyed by pressure during or after activation of the release mechanism.

[0011] According to further training, the aerospace aircraft features a clamping device designed as a ring element superimposed on the connecting element. This ring element is, for example, designed as a clamping ring or clamp. Before the separation mechanism is activated, the ring element secures the connecting element, and in particular the aforementioned clamping ring segments, in their positions at the end regions of the propulsion stages and presses them together. This ensures the transmission of all mechanical loads between the propulsion stages and the aircraft's assemblies until the propulsion stages separate.

[0012] According to one embodiment, the predetermined breaking point is designed as a notch or area of ​​material weakening in the clamping device. The predetermined breaking point is designed such that it breaks under overload conditions caused by the gas pressure that builds up in the gas mass flow when the pyrotechnic gas source is ignited, for example, in the engine of the advancing propulsion stage. The clamping device, which is designed in particular as a clamping ring or clamp, breaks at the predetermined breaking point under overload conditions due to the pressure-induced increase in circumferential stress. This circumferential stress results, firstly, from the pressure-induced increase in axial tensile force between the connected propulsion stages, which attempts to force the still-connected stages apart. This tensile force is converted into circumferential stress within the clamping device via the radial protrusions of the end regions and the connecting elements arranged there, such as clamping ring segments.Additionally, the gas pressure in the end region of the drive stage causes radial pressure to be applied to the fastener from its underside facing the end region, which also leads to an increase in the circumferential stress in the clamping device. The predetermined breaking point is designed such that it fails when a defined pressure level is exceeded, and the clamping device subsequently detaches from the fastener. After failure of the clamping device, the applied gas pressure causes radial acceleration of the fastener and its detachment from the end region of the drive stages or the radial protrusions provided there, which were previously engaged.

[0013] According to one embodiment, the first propulsion stage of the aerospace device has a void at its end. This void serves to contain a gas mass flow generated by the ignition of a pyrotechnic gas source in the second propulsion stage, e.g., the engine of the subsequent propulsion stage. The void preferably has at least one outlet opening for venting the gas mass flow. The outlet opening thus provides a gas guidance system that serves to control the separation of the propulsion stages with defined acceleration loads while simultaneously preventing excessive internal pressure in the void by preventing backflow of the gas mass flow.The outlet opening is additionally designed in such a way that the gas pressure in the gas mass flow is directed in such a way that it is first used to cause the failure of the clamping device based on the mechanical load and subsequently to bring about the separation of the connecting device from the drive stage by applying pressure to its inside.

[0014] In a preferred embodiment, the connecting element is arranged at the end region such that it covers the outlet opening. This advantageously increases the gas pressure acting on the underside of the connecting element facing the end region, thereby accelerating radial separation and thus facilitating the separation of the drive stages.

[0015] According to one embodiment, the outlet openings, and thus the gas guidance system formed by them, are designed such that the gas mass flow can be directed partly axially towards the first, preferably lower, propulsion stage and partly radially towards the connecting element. This advantageously ensures that the portion of gas from the void volume, which is directed axially opposite to the flight motion through the openings, facilitates or supports the separation of the separated bodies. This is achieved by expelling the gas from the void volume, which is structurally part of the rear stage, against the direction of motion.

[0016] Additionally, a further separation mechanism can be provided to support the separation of the propulsion stages. It proves advantageous to design this separation mechanism as a mechanically or pneumatically actuated braking device for the ejected propulsion stage, e.g., as an air cushion that can be filled by the gas mass flow and / or by oncoming airflow to increase aerodynamic drag and / or by deploying a braking parachute.

[0017] The aerospace device can also have a separate gas pressure generation device associated with the separation mechanism, which is designed to trigger the passive separation mechanism by pressurizing the connecting element. This advantageously provides a separate pressurized gas source that triggers the separation mechanism before the actual stage separation occurs through ignition of the second propulsion stage, e.g., the engine of the continuing propulsion stage.

[0018] According to one embodiment, the propulsion stages of the aerospace device, which have at least one passive mechanical separation mechanism, are separated in a controlled manner by a method comprising the steps described below. First, a pyrotechnic gas source is ignited in a propulsion stage, thereby generating a gas mass flow. This gas mass flow is then introduced into a void located in the end region of a propulsion stage, building up gas pressure within the void. The gas pressure is then released from the void towards the separation mechanism to generate mechanical stress in a clamping device provided in the separation mechanism until the clamping device fails upon exceeding a defined overload gas pressure.Following failure of the clamping device, it detaches, and at least one connecting element provided in the release mechanism detaches from an end region of the drive stages. This detachment is then followed or simultaneously by radial pressure application and acceleration of the connecting element by the applied gas pressure. In the next step, the release mechanism completely detaches from the drive stages, and the drive stages are subsequently separated. Because the controlled release of the release mechanism is achieved solely by the gas pressure generated in the drive stage, the method advantageously allows for passive release. This eliminates the need for active release mechanisms to carry out the separation process in the connecting element.

[0019] According to a further development, during the execution of the process, the gas pressure is dissipated radially onto an underside of the fastener facing the end region. The resulting radial pressure on the fastener is converted into a mechanical circumferential stress in the clamping device, which leads to its failure, whereupon the fastener, which may be designed, for example, as a segmented clamping ring, is released.

[0020] In one embodiment of the method, an axial discharge of the gas pressure is provided. Advantageously, the gas pressure in the gas mass flow is first used to induce the failure of the clamping device based on the mechanical load, then to bring about the separation of the connecting element from the drive stage by pressurizing it, and finally to support the separation of the drive stages after complete detachment of the connecting element. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The invention will now be explained with reference to the figures in the drawings. The figures show: Fig. 1 is a schematic exploded side view of an aerospace device according to an embodiment of the present invention; Fig. 2 is a schematic exploded view of a section of a propulsion stage connection of an aerospace device according to an embodiment of the present invention; and Fig. 3 is a schematic sectional view of a section of a propulsion stage connection of an aerospace device according to an embodiment of the present invention.

[0022] In the figures, the same reference symbols denote identical or functionally equivalent components, unless otherwise stated. DETAILED DESCRIPTION OF EXAMPLES OF THE INVENTION

[0023] Fig. 1Figure 1 shows a schematic side view of an aerospace device 10 according to an embodiment of the present invention. In the embodiment, the aerospace device is Figure 1 It is designed as a tactical missile. This missile has two propulsion stages 11, 12: a first, lower propulsion stage 11 and a second, upper propulsion stage 12 connected to it during operation. Both propulsion stages 11, 12 each have an engine, with the first, lower propulsion stage 11 igniting first during launch. After the lower propulsion stage 11 has burned out, the engine of the upper propulsion stage 12 ignites. The ignition of the upper propulsion stage 12 activates the separation mechanism 13, which is located between the first and second propulsion stages 11, 12 and ensures their connection during the thrust generated by the first propulsion stage 11. The in Fig. 1The separation mechanism 13 shown is designed as a passive separation mechanism 13, i.e., it does not include any active release elements such as pyrotechnically activated or destructible separation screws or the like. The separation mechanism 13 comprises a connecting element 14 and a clamping element 15, which holds the connecting element 14 at the opposing end regions 16a, b of the drive stages 11, 12 until the separation mechanism 13 is activated.

[0024] The lower propulsion stage 11 has a void volume 17, also referred to as a plenum, in its end section 16a. This volume serves to introduce a gas mass flow generated by the ignition of a pyrotechnic gas source in the second propulsion stage 12, i.e., in the engine of the subsequent propulsion stage 12. The void volume 17 has several outlet openings 18a, b for venting the gas mass flow. The outlet openings 18a, b thus provide a gas guidance system 19, which serves for the controlled separation of the propulsion stages 11, 12 with defined acceleration loads while simultaneously preventing excessive internal pressure in the void volume 17 by preventing backflow of the gas mass flow.The outlet openings 18a, b are designed such that the gas pressure in the gas mass flow is directed in such a way that it is first used to cause the failure of the clamping device 15 and subsequently to bring about the separation of the connecting device 14 from the drive stages 11, 12. The outlet openings 18a, b are round outlet openings 18a and slotted outlet openings 18b, respectively, provided in the circumferential wall 20 of the void volume 17. The slotted outlet openings 18b extend in the circumferential direction of the first drive stage 11. The outlet openings 18a, b discharge the gas pressure radially outwards. In the assembled state, i.e., before stage separation, the area of ​​the slotted outlet openings 18b is covered by the connecting device 14 or the clamping device 15.The clamping device 15 is covered so that the pressure dissipated via the slot-shaped outlet openings 18b acts on the underside 21 of the fastener 14 and is converted there into a circumferential stress introduced into the clamping device 15. The clamping device 15 fails when an overload pressure is exceeded and breaks at defined predetermined breaking points 26 or at clamping device areas that exhibit a material weakening (not shown).

[0025] Fig. 2 Figure 1 shows a schematic exploded view of a section of a drive stage connection of an aerospace device 10 according to an embodiment of the present invention. The disconnecting mechanism 13 is shown, which in the embodiment has a clamping element 15 designed as a clamping ring 22. The clamping ring 22 engages the connecting element 14, which in the embodiment is designed as a segmented clamping ring. Figure 2Figure 1 shows one of several clamping ring segments 23 that can be arranged around the lower edges 24a, b of the drive stages 11, 12. The clamping ring segment 23 is used in connection with Figure 3 Described in more detail.

[0026] The partially shown end regions 16a, b of the first and second drive stages 11, 12 have radial projections 25a, b on their mutually facing edges 24a, b, which provide shoulder flanks 28a, b that, in the assembled state, are partially engaged by the clamping ring segment 23. This creates a mechanical connection between the drive stages 11, 12.

[0027] In its assembled state, the clamping ring 22 overlaps the clamping ring segments 23 and presses them against the shoulder flanks 28a, b. To activate the passive separation mechanism 13 for the controlled separation of the propulsion stages 11, 12 of the aerospace vehicle 10, a pyrotechnic gas source in the second propulsion stage 12 is ignited after the propellant in the lower, first propulsion stage 11 has been consumed. This creates an axial gas mass flow that propagates in the direction of arrow R1 into the void 17 of the first propulsion stage 11. A gas pressure builds up in the void 17, which is discharged radially from the void 17 through the slot-shaped outlet openings 18b in the direction of arrow R2 to the clamping ring segments 23 covering the slot-shaped outlet openings 18b. There, the gas pressure creates a mechanical stress in the clamping device 15 via the clamping ring segment 23 until it fails when a defined overload gas pressure is exceeded.After failure of the clamping device 15, i.e., the breakage of one or more predetermined breaking points 26 provided in the clamping ring 22, it detaches from the clamping ring segment 23. The clamping ring segment 23 is subjected to further radial pressure by the still-applied gas pressure and is accelerated in the radial direction to be lifted off the end regions 16a, b of the propulsion stages 11, 12. After complete detachment of the clamping ring segments 23 forming the connecting device 14, the separation of the propulsion stages 11, 12 takes place. Axial pressure in the longitudinal direction of the aerospace vehicle 10 moves the lower propulsion stage 11, which is to be separated, away from the continuing upper propulsion stage 12, thus preventing any damage to the upper propulsion stage 12 or any impairment of its flight path.The components of the separation mechanism 13 are mechanically designed in such a way that a controlled passive release is achieved by the gas pressure generated in the upper drive stage 11.

[0028] Fig. 3 Figure 1 shows a schematic sectional view of a section of a drive stage connection of an aerospace device 10 according to an embodiment of the present invention in the assembled, non-activated state. The separation mechanism 13 is shown in section. The end regions 16a, b of the drive stages 11, 12 are flush against each other. The joint area 27 is covered by a clamping ring segment 23, which has laterally projecting flanges 32a, b that bear positively onto the end regions 16a, b. The Fig. 3The clamping ring segment 23 shown is one of several clamping ring segments 23 arranged along the circumference of the drive stages 11, 12, which together form the connecting element 14 of the separating mechanism 13.

[0029] The partially shown end regions 16a, b of the first and second propulsion stages 11, 12 have radial projections 25a, b on their facing edges 24a, b, forming circumferential shoulder flanks 28a, b. These shoulders are engaged by the clamping ring segments 23 to achieve a mechanical connection between the propulsion stages 11, 12 and to transmit mechanical loads between the propulsion stages or aircraft assemblies. The clamping ring segments 23 are connected by a Fig. 3 also the clamping ring 22 shown in the freestanding section and pressed by it against the shoulder flanks 28a, b.

[0030] In the exemplary embodiment, the clamping ring 22 has several predetermined breaking points 26 which fail when a defined load is exceeded, resulting in the controlled fracture of the clamping ring 22. The overload is achieved by the gas pressure built up in the empty volume 17 of the first propulsion stage 11 when the pyrotechnic gas source is ignited, for example, in the engine of the subsequent propulsion stage 12. This gas pressure initially acts on the clamping ring segment 23, which presses outwards against the clamping ring 22 and generates a circumferential stress within the clamping ring 22. The circumferential stress also results from the pressure-induced increase in axial tensile force between the connected propulsion stages 11 and 12, which attempts to force the still-connected stages apart. This tensile force is also converted into the circumferential stress within the clamping ring 22 via the radial projections 25a and b of the end regions 16a and b and the clamping ring segments 23 located there.The predetermined breaking point 26 is designed such that it fails when a defined pressure level and the resulting circumferential stress are exceeded, after which the clamping device 15 subsequently detaches completely from the connecting device 14. After failure of the clamping device 15, the applied gas pressure causes a radial acceleration of the connecting device 14 and its detachment from the end region 16a, b of the drive stages 11, 12 or the radial projections 25a, b provided therein, which were previously engaged.

[0031] For assembly, the clamping ring 22 is pulled onto the clamping ring segments 23 after the drive stages 11, 12 have been flush connected and the clamping ring segments 23 have been placed on the butt joint 27 or the shoulder flanks 28a, b, respectively, and closed using a lever connector 29. For this purpose, an adjusting screw 30 connected to the lever connector 29 engages a hook arrangement 32 welded to the clamping ring surface 31. When the lever connector 29 is closed, the clamping ring 22 is closed and presses the clamping ring segments 23 arranged below it into their position at the end regions 16a, b of the drive stages 11, 12. Instead of using in Fig. 3 In addition to the predetermined breaking points 26 provided in the clamping ring 22, it is also possible that the adjusting screw 30 is provided with a predetermined breaking point 26 and that the adjusting screw 30 breaks when an overload pressure is exceeded. REFERENCE MARK LIST

[0032] 10 Aerospace or spacecraft 11 First propulsion stage 12 Second propulsion stage 13 Separation mechanism 14 Connecting element 15 Tensioning element 16a, b End area 17 Empty volume 18a, b Outlet opening 19 Gas guidance system 20 Circumferential wall 21 Underside 22 Tension ring 23 Clamping ring segment 24a, b Edge 25a, b Raised section 26 Shear point 27 Impact area 28a, b Shoulder flank 29 Lever connector 30 Adjusting screw 31 Tension ring surface 32a, b Flange R1, R2 Arrow direction

Claims

1. Aerospace device (10) comprising a first lower propulsion stage (11) and at least one second, upper propulsion stage (12) connected to the first, and a propulsion stage connection having a passive separation mechanism, wherein the separation mechanism (13) has at least one controllably detachable connecting element (14), wherein the connecting element (14) is arranged on the circumference of mutually facing end regions (16a, b) of the propulsion stages (11, 12) and is held by a circumferential clamping element (15), and the clamping element (15) has at least one form-fit or force-fit structural connection and / or a predetermined breaking point (26) that fails under defined overload.

2. Aerospace device (10) according to claim 1, characterized by the fact that The connecting element (14) is designed as a segmented clamping ring and individual clamping ring segments (23) overlap radial projections (25a, b) of the end regions (16a, b) at least section by section.

3. Aerospace device (10) according to claim 2, characterized by the fact that the clamping ring segments (23) can be connected via material- or force-fit structural connections that fail under defined overload.

4. Aerospace device (10) according to claim 2 or 3, characterized by the fact that the radial elevations (25a, b) form shoulder flanks (28a,b) having beveled guide surfaces on the circumference of the end regions (16a, b) and the clamping ring segments (23) can be attached to the shoulder flanks (28a,b) in a form-fitting manner.

5. Aerospace device (10) according to any one of the preceding claims, characterized by the fact that the clamping device (15) is designed as a ring element superimposed on the connecting device (14), in particular as a clamping ring (22), and the predetermined breaking point (26) is designed as a notch or area with material weakening in the clamping device (15).

6. Aerospace device (10) according to any one of the preceding claims, characterized by the fact thatThe driving stages (11, 12) in their respective end regions (16a,b) have a void volume (17) to receive a gas mass flow generated by ignition of a pyrotechnic gas source and the void volume (17) has at least one outlet opening (18a, b) for discharge of the gas mass flow.

7. Aerospace device (10) according to claim 6, characterized by the fact that the connecting element (14) is arranged covering the outlet opening (18a, b) at the end area (16a, b).

8. Aerospace device (10) according to claim 6 or 7, characterized by the fact that the gas mass flow can be directed partly axially in the direction of the first drive stage (11) and partly radially in the direction of the connecting means (14).

9. Method for the controlled separation of a propulsion stage connection of an aerospace device (10) according to any one of claims 1 to 8, wherein the propulsion stage connection has at least one passive, mechanical separation mechanism (13), comprising the steps of: - ignition of a pyrotechnic gas source in one of the propulsion stages (11, 12) and generation of a gas mass flow, - introduction of the gas mass flow into an empty volume (17) provided in the end region (16a, b) of one of the propulsion stages (11, 12) and build-up of a gas pressure in the empty volume (17), - discharge of the gas pressure from the empty volume (17) towards the separation mechanism (13) to generate a mechanical stress in a clamping element (15) provided in the separation mechanism (13) until the clamping element (15) fails upon exceeding a defined overload gas pressure, - release of the clamping element (15) and at least one connecting element (14) provided in the separation mechanism (13) from an end area (16a,b) of the driving stages (11, 12) and radial acceleration of the connecting element (14), - release of the separation mechanism (13), - separation of the driving stages (11, 12)., 10. Method according to claim 9, characterized by the fact that The gas pressure is directed radially to a bottom surface (21) of the connecting element (14) facing the end region (16a, b) to separate the drive stages (11, 12) and axially into the empty volume (17) of the first drive stage (11).

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