FR2847306A1 - Ramjet or post-combustion rocket engines air inlet, has control mechanism with spring hinged between front part of valve and air passage, lever to pivot and displace valve articulated on back part of valve - Google Patents

Abstract

The air inlet has a closing check valve (10) covering an inlet periphery and including a front part (11) in a flow direction and a back part (12). A control mechanism has a spring (30) hinged between the front part and an air passage, and a lever (31, 32, 33) to pivot and displace the valve articulated on the back part. The back part is guided through a control zone adjacent to a cam shaped part (34). An Independent claim is also included for a method for manufacturing air inlet.

Description

AIR INLET FOR PROPELLER AND ITS MANUFACTURE

  The present invention relates to an air inlet for an air channel of propellants using ambient air, in particular ramjet engines or rocket engines with post-combustion of missiles having a supersonic flight speed, with a contour of inlet, a closing valve covering the inlet contour, located inside and comprising a front part seen in the direction of the flow and a rear part, and a control mechanism intended to open the

closing.

  Among other things, ramjet engines or afterburner rocket engines are used for missiles, which can be transported and launched by carrier aircraft. Thanks to the closing valve in front of the air intake, the buzzer of the diffuser is prevented during the acceleration and supersonic cruising flight phase as well as the penetration of foreign bodies. In addition, the anterior edges of the air intake inlet, tapered and fragile, are, thanks to the closing valve, optimally protected, during cruise flight against wear but also against denting. improper handling, for example, during transport. In addition, the cover allows, thanks to the closing valve, to have, during the start and cruise flight, a

  low resistance aerodynamic current.

  Document DE 196 51 491 A1 discloses an air inlet for an air channel with a closing valve situated inside and covering the inlet contour of the air channel, and for which the closing valve in one piece, is adapted so that it covers the front edges in the closed position and is opened by means of a control mechanism. In addition, this control mechanism consists of a guide ramp, along which the rear part of the closing flap, seen in the direction of flow, slides to the open position due to the air thrusts generated . The front part of the closing valve in the direction of the flow is at the same time pulled backwards by means of a sliding slide positioned on the upper face of the air inlet. The movement of the rear part can be supported and / or damped by springs of

  traction and damping cylinder systems.

  A drawback lies in the fact that for such a closure system for an air intake, it may occur, during opening, due to the imprecision of the guidance performed by the proposed control mechanism, warping of the closing valve, and therefore it is not possible to guarantee rapid and complete opening of the closing valve in less than a few milliseconds when

  the Mach number has been reached.

  The object of the invention is therefore to further develop an air intake for a propellant air channel using ambient air, with a closing valve, so that it is possible to open the closing valve in a few milliseconds, without the risk that the closing valve will warp or remain hooked for defined wind surges. However, the closing valve must continue to prevent the penetration of foreign bodies into the air intake, during the acceleration and then supersonic flight phase, to protect from wear and denting, the front edges of the intake of the air intake, tapered and fragile, and moreover, to have, during the carried and cruising flight, a low resistance with regard to the aerodynamic current. In addition, a method must be indicated for the manufacture of such an air inlet with

closing valve.

  To achieve the goal concerning the air inlet with closing valve, an air inlet of the type previously described according to the invention is characterized in that the control mechanism comprises a device forming a spring articulated between the front part of the valve and the air channel, and means for pivoting and moving the rear part of the closing valve, articulated in the rear part

of the closing valve.

  Thanks to the device forming a spring articulated between the front part and the air channel, device which can, in the simplest case, consist of a spiral spring or another constellation of springs provided with energy , in a state of stress, and at the force thus applied, the front part of the closing valve is driven in the direction of the force when the opening mechanism is released and performs a determined movement in the direction of the force. In addition, it should be added that the rear part of the closing valve, by means of appropriate means, is pivoted and moved from the closed position to the open position. Thus, the two parts of the closing valve are guided from one position to the other, and are not subjected to an uncontrolled movement, knowing that it will be impossible to have warping or blocking. But it is also possible, thanks to the system of the closing valve placed inside with a device forming a spring on the front part of the valve and the means for moving and pivoting the rear part of the closing valve, to prevent penetration foreign bodies in the air channel during acceleration and supersonic cruising flight but also to protect the anterior edges of the air intake, tapered and fragile, against wear and denting. In addition, the constellation according to the invention offers low resistance to air from the aerodynamic current.

  during the start and cruise flight.

  To move the closing valve from the closed position to the open position, it is possible to use drive means of any type, such as motors, additional springs or equivalent, conforming to the state of the drive technique. ; it is however advantageous that the spring device is nevertheless positioned between the front part of the closure valve and the air channel, so that the energy which has been stored therein will be used when the opening mechanism is released to move the closing valve. As a variant, or in addition, it is also possible to use the air thrusts which act during the flight on the closing flap to generate the force necessary for the displacement. In this way, it is possible, without additional construction expenditure, and only with the means available, to execute the movement of the closing valve, which leads to savings in components and in manufacturing costs. The means for moving and pivoting the rear part of the closing valve are preferably composed of levers sliding linearly in the direction of flow. In particular, it is preferable for the rear part of the closure valve to be in active connection, by means of a lever articulated in an orientable manner relative to the closure valve, this lever also being articulated in an orientable manner on an arm, with the air channel at a sliding articulation point. Such constructions are easy to manufacture and handle; they perform

  very precisely the sequence of movements required.

  The rear part of the closing valve is advantageously guided by means of a shaped part of the air inlet having the shape of a control cam. In addition, the closing valve has a control zone which is firmly attached thereto, and which transmits to the shaped part the movement of the rear zone of the closing valve. In particular, it is clearly advantageous for the control area to be a single arm firmly

  articulated on the closing valve.

  Thanks to the control zone positioned on the shaped part and moving the control cam, the movement of the rear part of the closing valve is fixed and specified so that the false movements, which are still possible by means of the device forming spring or pivoting and displacement means, are completely eliminated by

additional guidance.

  The initiation of the linear movement during the course of the movements of the rear part of the closing valve can be achieved in a variety of ways. Thus, an unlocking of locking devices is conceivable, but preferably a sliding slide, fixed by means of a locking device during accelerating and supersonic cruising flight, frees, upon release of the locking device, the path for the sliding of the rear part of the closing flap, and thus for the opening of the flap

closing.

  In particular, this is a very simple procedure when the spring device and / or the air pushes act a lasting force on the closing valve and one can thus define a precise starting point for the opening procedure. But even then, when the opening of the closing valve must be carried out in another way, correct release is guaranteed. In addition, it is easy, due to the reduced height of the construction, to present and implement everywhere a closure by means of a sliding slide without the components present being affected by their operation. In addition, the release or blocking device can be arranged and offset locally from the active location, where there is the construction height or the space to do this. In addition, the blocking device can be produced in very different ways and depending on the possibilities of the state of the art, so that preferably it is nevertheless a double security system, which comprises preferably a locking bolt which directly releases the sliding slide and which can move thanks to a control piston. In addition, the control piston is installed in a pressure cylinder and is fixed there, with respect to its driving stroke, by means of a safety pin. If pressure is introduced into the pressure cylinder, the safety pin moves backwards and releases the control piston, which then executes its driving stroke and sets in motion the locking bolt, which has the effect that the sliding slide can be moved. This blocking device has the advantage that double security with the secure control piston is guaranteed against an unforeseen release, knowing that however thanks to the introduction of pressure, it is possible to

  proceed quickly and reliably to the release.

  The flow close to the wall (boundary layer) is disturbed due to the viscosity of the air, which leads to a reduction in the efficiency of the air guide system. In order to compensate for this point, the boundary layer can be evacuated to the outside. In the case where the air inlet has an air bypass channel for the derivation of the boundary layer, this should also be closed in order to protect against dirt or mechanical damage during the accelerating flight. or supersonic cruise. This protection must be opened, if necessary, as briefly as possible when the closing valve is opened, which can be done by means of an own opening device, but which is preferably carried out when the sliding slide at the same time frees the air bypass channel during its movement. In this way, we use a component for several functions, which allows us to make

  savings and guarantees exact simultaneity.

  In a particularly preferred manner, the air bypass channel is closed in the closed position with a sealing part, which is held in the locked position by means of the sliding slide, which is released by the movement of the sliding slide and which is ejected by the incoming air flow. The advantage of such a structure for closing the air bypass channel lies in the fact that the sliding slide can only execute a positioning movement reduced relative to the width of the air bypass channel and must not move over the entire width of the opening. It suffices to execute only the single maneuvering stroke which corresponds to the engagement and / or the undercut between the sliding slide and the sealing part. This has the effect that the movements of the sliding slide for the opening of the closing valve and for the ejection of the sealing part must not, in addition, be synchronized. When the closing valve is in the open position, the rear part of the closing valve is fixed by the spring force of the spring device and / or by the air pushes acting on the closing valve. These forces can also keep the front part of the closing valve in the open position. But preferably, the front part of the closing valve will be held by a fixing device placed between the closing valve and the air inlet, knowing that it is in this case preferably having a sliding lock snapping into a groove and prestressed by a spring. This is then above all advantageous when the geometry of the front part of the shut-off valve is executed in such a way that the forces of the air flow are interrupted or can be subjected to

changes in direction.

  The solution enabling the objective concerning the manufacturing process to be achieved is characterized according to the invention by the fact that the components arranged in the air channel are screwed with the sliding slide by means of mounting screws, this assembly is guided from the front in the air channel and the mounting screws, after fixing the components, are removed

from the outside.

  This manufacturing process offers the possibility, compared to an assembly of the various components, to completely assemble the assembly outside the air channel which has a very reduced construction height, from the components arranged at the interior with sliding slide, and

  greatly simplify the assembly.

  The invention will be described in more detail using an embodiment shown in the drawings and to which other features, technical characteristics and qualities will relate. We can see that Figure 1 shows a section in the longitudinal direction of an air inlet according to the invention, with the closing valve in the closed position, Figure 2 shows a section corresponding to Figure 1 with the valve closing in the open position, and FIG. 3 represents a cross section of an air inlet according to the invention, corresponding to

  Figure 1, along a line A-A.

  In the figures where identical parts are provided with identical references, the air intake for a thruster of a missile is shown, which serves, for example, to be driven by carrier planes and to be actuated during the flight . The air intake must be closed, both during handling on the ground and during the flight until the launching process, in order to prevent the penetration of foreign bodies such as hailstones, stones, birds or water and that around the air inlet which comprises, in the case of the embodiment shown, a rectangular section, a safety device is generated, so that it cannot change its original shape and / or does not deform locally. At the same time, the tapered peripheral edges of the air intake inlet contour in the flight direction must be protected, in the flight direction, from wear during cruise flight, so that they have no

exposed position.

  FIG. 1 represents the air inlet 1 for the air channel 20 of a ramjet with an air bypass channel 60 intended for the bypass of the boundary layer. The closing valve 10, which completely closes the inlet contour, which is adapted to the latter, and which covers in its closed position the tapered front edges 21, 22 with the lateral flanks 21a, 21b (see fig. 2) , is made in one piece and is connected to a control mechanism. The control mechanism consists of a spiral spring 30 which is articulated between the front part II of the closing valve 10 and a point of articulation 25 of the spring on the air channel (in the overview, the spring is not fully drawn so as not to cover the lever mechanism 31, 32, 33). In this way, the closing valve 10 is, in the closed position, pressed and fixed against the front inlet edge 21. In addition, a rubber lip 18 seals the air inlet between the two components. The rear part 12 of the closure valve 10 is connected to the air channel by means of a movable articulation point 31 by means of a sliding slide 50. In addition, a lever 33 pivotally articulated with the closing valve 10 is pivotally connected to an arm 32 disposed on the articulation point 31. The sliding slide 50 is fixed vis-à-vis a vertical movement, by means of a locking bolt 81. In the closing valve 10 closed, the combination of levers 31, 32, 33 presses the rear part 12 of the closing valve 10 against the rear inlet edge 22 and its sealing with respect to this is ensured by a lip sealing 19. At the same time, the rear part 12 of the closing valve 10 is further guided by means of a control cam. To do this, a part of the closing valve formed as an arm 15 is adjacent to a shaped part 34 designed in the form of a control cam. This part is firmly positioned on the wall of the air channel 20 and during a movement of the rear part 12 of the closing valve 10 moves the latter from the extended position (closed position) to the final position (open position ). In the closed position, the closing effect of the spring 30 is mechanically supported by the heel of the shaped part 34 relative to the arm 15. In the closed position, the elasticity of the spiral spring 30 and the air pushes applied from the outside to the closing valve 10 exert, in the case of the present embodiment, a force thereon, which force reinforces the opening action and leads to the opening of the closing valve 10. As a variant, it would also be possible to guarantee in another way, for example by means of a drive system, the force

  to open the closing valve 10.

  Thanks to the vertical fixing of the articulation point 31 on the sliding slide 50 by means of the locking bolt 81 and thanks to the arm 15 adjacent to the shaped part 34, the closing valve nevertheless does not perform any opening movement despite the applied force. The opening can then take place only if, after the end of the acceleration phase, for example, for a speed greater than Mach 2, the thruster is put into service, the closing valve 10 in front, within a shorter period a few milliseconds, free the air intake. This is then carried out in the embodiment shown, when the sliding slide 50 is released towards the rear. The release of the sliding slide 50 and consequently an opening of the closing valve 10 will be controlled by means of a locking device 80. To do this, a vertically movable locking bolt 81 fixes the sliding slide 50 in its starting position. . The locking bolt 81 is moved by means of a control piston 82. To do this, the control piston 82 is installed in a pressure cylinder 83 which can be actuated with gas. The control piston 82 is held by means of a safety pin 84 formed by an additional control piston, snapping into a groove on the control piston 82, in order to prevent, during the flight, an involuntary operation of the sliding slide 50. In the event of pressure actuation of the pressure cylinder 83, the safety pin 84 positioned in a movable and resilient manner is pressed out of the groove on the control piston 82, and the control piston 82 then moves by itself downwards, which causes the locking bolt 81 to release the sliding slide 50. But as a variant, it would also be possible for the control piston 82 to eject the safety pin 84 and thus the sliding slide is released. After the release of the sliding slide, the articulation point 31 connected to the sliding slide moves the lever 33 backwards and the arm 15 moves rearwards on the shaped part 34. At the same time, the front part 11 of the closing valve is pulled inward by the force of the spiral spring 30. In addition, the sliding slide 50 also releases during the rearward movement the sealing part 70, which, in the closed position, protects of dirt the air bypass channel 60, which in the closed position, is retained undercut by the sliding slide 50 and which in the event of release is ejected by the pressure of the air leaving the channel

air bypass 60.

  FIG. 2 shows the air inlet 1 in the open position, with the closing valve 10 folded inwards and the bypass channel of

air 10 open.

  The locking bolt 81 has released the sliding slide 50, the elasticity of the spiral spring 30 and the force of the air pushes have the effect that the sliding slide 50 and the articulation point 31 are moved backwards and that the closing valve 10 is folded over the arm 32 and the lever 33 in the rear part 12. In the final position, that is to say in the open position, the rear part 12 of the closing valve 10 s' extends on the articulation point 25 or else the arm 15 stabilizes the system and is thus positioned on the upper wall. In this way, the rear part 12 of the closing valve 10 is moved from the closed position to the open position and is in a stable final position. The front part 11 of the closing valve 10 has pivoted inwards, a sliding bolt 41, prestressed by a spring, snapping into the

  groove 13 in order to maintain the open position.

  Section A-A, passing through the air inlet 1 and shown in Figure 3, shows that the system of the control mechanism is produced symmetrically with respect to the median axis B-B. Thus the sliding slide 50 is produced in the form of a plate with two points of articulation 31. On the two points of articulation 31 are the arms 32 on which the levers 33 are again pivotally articulated. 33 separately support at their end the rear part 12 of the closing valve 10. It can also be seen that the front part 11 of the closing valve 10 is fixed to the air channel at the

  by means of two spiral springs 30.

Claims (12)

  1. Air inlet (1) for an air channel (20) of thrusters using ambient air, in particular ramjet engines or rocket engines with post-combustion of missiles having a supersonic flight speed, with a inlet contour, a closing valve (10) covering the inlet contour, situated inside and comprising a front part (11) seen in the direction of the flow and a rear part (12), and a mechanism for control for opening the closing valve, characterized in that the control mechanism comprises a spring device (30) articulated between the front part (11) of the closing valve (10) and the air channel (20), thus that means (31, 32, 33) for pivoting and moving the closing valve articulated on the rear part (12) of the closing valve (10).   2. Air inlet (1) according to claim 1, characterized in that the spring device (30) and / or thrusts of air on the closure valve (10) generate a force to rotate and   move the closing valve (10).   3. Air inlet (1) according to claim 1 or 2, characterized in that the means for pivoting and displacement are levers (31, 32, 33) sliding   linearly in the direction of flow.   4. Air intake (1) according to one or more of   previous claims, characterized in that the   rear part (12) of the closing valve (10) is guided by means of a control zone adjacent to a shaped part (34) having the form a control cam.   5. Air inlet (1) according to claim 4, characterized in that the control zone is formed by an arm (15) on the closing valve (10). 6. Air inlet (1) according to any one of   previous claims, characterized in that it   comprises a sliding slide (50) fixed by means of a blocking device (80) and allowing, when the blocking device (80) is released, a displacement   and thus an opening of the closing valve (10).   7. Air inlet (1) according to claim 6, characterized in that the locking device (80) comprises a locking bolt (81) fixing the sliding slide (50), movable by means of a control piston (82) installed in a pressure cylinder (83) and fixed with respect to its driving stroke by means of a safety pin (84), and the safety pin (84) releases the control piston (82 ) if pressure is introduced into the cylinder pressure (83).   8. Air inlet (1) according to claim 6 or 7, characterized in that the sliding slide (50) frees, during sliding, a bypass channel of   air (60) for the derivation of the boundary layer.   9. Air inlet (1) according to claim 8, characterized in that the sliding slide (50) ejects during sliding a sealing part (70)   which closes the air bypass channel (60).   10. Air inlet (1) according to any one of   previous claims, characterized in that a   fixing device fixes the front part (11) of the   closing valve (10) in an open position.   11. Air inlet (1) according to claim 10, characterized in that the fixing device is a sliding bolt (41) snapping into a groove   (13) and prestressed by a spring.   12. Method for manufacturing an air inlet (1) according to claim 6 or any one of   claims 7 to 11 related to the claim   6, characterized in that components arranged in the air channel (20) are screwed, by means of mounting screws, with the sliding slide (50), this assembly is guided from the front into the air channel (20), and the mounting screws, after fixing the   components, are removed from the outside.