DISCHARGE DOOR CONTROL DEVICE FOR AN AIRCRAFT TURBOMACHINE

Abstract

Device (50) for controlling discharge doors (52) for an aircraft turbomachine (10), this device (50) comprising: - a series of discharge doors (52), and - a system (54) for controlling the discharge doors (52) comprising at least one cylinder (56) comprising a fixed cylinder (58) and a movable piston (60), characterized in that the control system (54) is of the octopus type and comprises a first single part (54a) connected to the movable piston (60) and a second part (54n) divided into several branches (62) which each extend between the first part (54a) and the discharge doors (52), the number of branches (62) being equal to the number of discharge doors (52) and the branches (62) being respectively connected to the discharge doors (52). Figure for abstract: Figure 3

Description

Title of the invention: DEVICE FOR CONTROLLING DISCHARGE DOORS FOR AN AIRCRAFT TURBOMACHINE Technical field of the invention

[0001] The present invention relates to a discharge door control device for an aircraft turbomachine, as well as a turbomachine comprising such a device. Technical background

[0002] The state of the art includes in particular documents FR-A1-3 082 562, FR-A1-3 083 577 and FR-A1-3 119 421.

[0003] An aircraft turbomachine comprises a gas generator which conventionally comprises, from upstream to downstream, with reference to the flow of gases in the turbomachine, at least one compressor, an annular combustion chamber and at least one turbine. In the case of a twin-spool turbojet engine, respectively low pressure and high pressure, the gas generator successively comprises a low pressure compressor, a high pressure compressor, the combustion chamber, a high pressure turbine and a low pressure turbine. The gas generator defines a first annular flow vein for a gas flow, called the primary flow, which passes through the compressors, the combustion chamber and the turbines.

[0004] The rotor of the high pressure compressor is connected to the rotor of the high pressure turbine by a high pressure shaft. The rotor of the low pressure compressor is connected to the rotor of the low pressure turbine by a low pressure shaft which passes through the high pressure shaft and which rotates a propulsion propeller generally located upstream of the gas generator.

[0005] When this propeller is shrouded and therefore surrounded by an annular casing, this propeller is called a fan and generates an air flow, called a secondary flow, which flows around the gas generator.

[0006] Discharge doors are generally installed in an annular row at the compressor(s) of the gas generator, and in particular between the low-pressure and high-pressure compressors. Their opening and closing serve to adjust an air leakage flow rate from the flow vein of the primary flow to the flow vein of the secondary flow, depending on the operating conditions of the turbomachine, for example to avoid a surge phenomenon.

[0007] The discharge doors are distributed around a first axis and each pivotally movable relative to a second axis tangent to a circumference centered on the first axis. The discharge doors are controlled by a control system which allows them to be moved in synchronized pivoting around their second axes. In a known manner, this control system comprises one or more actuators, for example jacks, comprising a fixed cylinder and a movable piston.

[0008] Prior art control systems are often heavy and bulky due to their complexity. For example, they comprise a large number of rigid components which are articulated by complex connections.

[0009] More specifically, the technical constraints and problems of known control systems are as follows.

[0010] - The mass of the components between the cylinder and the discharge doors can represent several kilograms. The mass depends primarily on the installation diameter and the actuation force to be transmitted. The combination of these two parameters results in volumes of material, the part of which intended for force transmission requires provisions of material intended to ensure satisfactory stiffness of the system, a guarantee of its precision. On current motors, the aforementioned mass can represent around ten kilograms.

[0011] - The size of these systems has a significant impact on the constraints installation, as well as on the accessibility of components and the design of surrounding parts.

[0012] - The mass / limitation of the complexity of systems compromise leads to positioning the cylinder quite close to the discharge doors, which is restrictive for the installation, the aerodynamic lines of the primary and secondary flows, and the type of cylinder. Furthermore, the use of a fuel-powered hydraulic cylinder implies an extended fire protection zone with effects on the surrounding parts.

[0013] - The lifespan of these systems is linked to the durability of the articulated connections. These Components considered as consumables in the assembly condition maintenance interventions sometimes anticipated of the systems. In addition, these connections being the preferred place of damping / accommodation of the system, additional degradations can occur following a behavioral drift of an external operator. Consequently, systems reinforced by coatings or specific materials must be provided to support for example a significant mass of the systems or vibration coupling phenomena.

[0014] - The current control precision is linked, in addition to the stiffness of the components, the number of intermediate mechanical connections that require internal operating clearances. The accumulation of clearances increases as the connections wear, thus degrading the precision of the system.

[0015] - The complexity of these mechanisms is a direct source of manufacturing costs.

[0016] The present invention provides a solution to at least some of the problems of the prior art, which is simple, effective and economical. Summary of the invention

[0017] The invention relates to a device for controlling discharge doors for an aircraft turbomachine, this device comprising:

[0018] - a series of discharge doors distributed around a first axis and movable each pivoting relative to a second axis tangent to a circumference centered on the first axis, and

[0019] - a system for controlling the discharge doors for their syn-pivoting chronographed around their second axes, this control system comprising at least one actuator such as a jack, comprising for example a fixed cylinder and a movable piston,

[0020] characterized in that the control system is of the octopus type and comprises a first single part connected to the actuator, and in particular to the movable piston, and a second part divided into several branches which each extend between the first part and the discharge doors, the number of branches being equal to the number of discharge doors and the branches being respectively connected to the discharge doors, the control system being configured to transform a translational movement of the actuator into a pivoting movement of the discharge doors.

[0021] The present invention thus proposes to use an octopus control system. An octopus comprises a single body connected to several tentacles. In the context of the present invention, the control system comprises a single part forming the body of the octopus, and several branches forming the tentacles of the octopus. It is therefore understood that each of the discharge doors is connected to one end of a branch and that the opposite ends of all the branches are connected to the single part which ensures the connection between these branches and the movable part of the actuator. The movable part of the actuator transmits traction and thrust forces to the system which are transmitted to the discharge doors for the purpose of pivoting them and therefore opening and closing them.

[0022] The configuration of the control system makes it possible to eliminate several disadvantages and problems of the prior art. On the one hand, the system can be simpler and lighter than those of the prior art. Furthermore, it makes it possible to move the actuator away from the discharge doors and therefore not to clutter the environment around the discharge doors with the cylinder. Furthermore, in the case where the actuator is hydraulic and operates using a flammable hydraulic fluid, such as fuel, it would make it possible to move the fire zone induced by the supply of fuel to the cylinder away from the discharge doors.

[0023] The system may comprise one or more cylinders, namely a single cylinder which is connected by the octopus to all of the discharge doors, or two or more cylinders which are each connected by an octopus to a part of the discharge doors. We therefore understand that the number of octopuses depends on the number of jacks and in particular is equal to the number of jacks.

[0024] The device according to the invention may comprise one or more of the following characteristics, taken in isolation from one another or in combination with one another: - the first part is connected to the branches by a sliding multiplexing member; - the first part comprises a tubular sheath inside which is capable of sliding an elongated blade, a first end of which is connected to the actuator, and in particular to the movable piston, and a second opposite end of which is connected to the branches;

[0025] — the cable is rigid, semi-rigid or flexible; - the second end of the blade is connected to the multiplexing member which is connected to each of the branches; - the first end of the blade is connected to the actuator by being engaged in a slot of the actuator, and in particular of the piston, and by being immobilized in this slot by cooperation of shapes and screwing of a nut around this end; - each of the branches comprises a rectilinear portion located on the side of the first part, and a non-rectilinear portion located on the side of the discharge doors; - each of the branches comprises at least two rectilinear portions located on the side of the first and second parts, and an intermediate rectilinear and / or non-rectilinear portion, - the straight portion of each branch is rigid or flexible, and the non-straight portion of each branch is flexible;

[0026] — the straight portions of the branches are joined together and secured to each other, and the non-rectilinear portions of the branches are independent of each other; - each of the branches comprises a cable, preferably flexible, which comprises a tubular sheath inside which an elongated blade is capable of sliding; - the blade of each of the branches has an end which is connected to the multiplexing member by a ball joint; - the blade of each of the branches has an end which is connected to the multiplexing member by a ball joint; - the blade of each of the branches has one end which is connected to the corresponding discharge door by a chain and / or a connecting rod;

[0027] — the chain has one end connected to the end of the blade and one end opposite connected to one end of the connecting rod, one opposite end of which is connected to the discharge door; the chain is useful in the event of a requirement for a bent path, particularly in the case of a radius of curvature incompatible with the bending capacity of the blade; - the chain is movable in translation, for example by rolling, inside a sheath, preferably bent; the chain is preferably guided by rolling using rollers for example in the sheath; it is then a translation by rolling and not by friction; the chain is articulated; - at least one of the ends of the connecting rod comprises a ball joint, and / or at least one of the ends of the chain comprises a ball joint; - the device further comprises an annular casing which extends around the first axis, as well as supports of the control system which are carried by the casing; - the supports comprise several arms which extend, for example axially or radially, outwards from the casing and which comprise at their free ends opposite the casing fixing elements, such as mounting collars;

[0028] — the actuator is electric or hydraulic.

[0029] The present invention also relates to an aircraft turbomachine, comprising at least one device as described above. Brief description of the figures

[0030] Other characteristics and advantages of the invention will appear during the reading of the detailed description which follows for the understanding of which reference will be made to the appended drawings in which:

[0031] [Fig-1] [Fig.l] is a half schematic view in axial section of a part of a aircraft turbomachine,

[0032] [Fig.2] [Fig.2] is a schematic perspective view of a discharge door control device according to the prior art,

[0033] [Fig.3] [Fig.3] is a very schematic view of a discharge door control device according to the invention,

[0034] [Fig.4] [Fig.4] is a schematic perspective view of an embodiment of a discharge door control device according to the invention,

[0035] [Fig.5] [Fig.5] is a schematic perspective view of a sliding blade cable of the control system according to the invention,

[0036] [Fig.6] [Fig.6] is a schematic sectional view of the sliding blade cable of the [Fig.5],

[0037] [Fig.7] [Fig.7] is a schematic perspective view of the jack and the connection between a first part of the control system and the cylinder,

[0038] [Fig.8] [Fig.8] is a schematic perspective view on a larger scale of part of the jack of [Fig.7],

[0039] [Fig.9] [Fig.9] is a schematic perspective view of the connection between the first part of the control system and the cylinder of [Fig.7],

[0040] [Fig. 10] [Fig. 10] is a schematic view of a variant of the connection between the first part of the control system and the cylinder,

[0041] [Fig. 11] [Fig. 11] is a very schematic view of cables of a second part of the control system according to the invention,

[0042] [Fig.l2a-12b] Figures 12a and 12b are schematic perspective views of the connection between a cable end and a discharge door of the control system according to the invention,

[0043] [Fig.l3a-13b] Figures 13a and 13b are schematic perspective views of a discharge door and illustrate two extreme positions of this discharge door,

[0044] [Fig.l4a-14b] figures 14a and 14b are schematic perspective views of a another discharge door and illustrate two extreme positions of this discharge door,

[0045] [Fig. 15] [Fig. 15] is a schematic perspective view on a larger scale of the connection at one end of the cable of the second part of the control system according to the invention Detailed description of the invention

[0046] [Fig.l] shows a turbomachine 10 for an aircraft, this turbomachine 10 here being a double-flow, double-spool turbojet.

[0047] Axis A designates the longitudinal axis of the turbomachine.

[0048] The turbomachine 10 comprises a gas generator 12 which comprises from upstream to downstream with reference to the flow of gases along the axis A, a low pressure or LP compressor 14 or a high pressure or HP compressor 16, an annular combustion chamber, a high pressure or HP turbine and a low pressure LP turbine.

[0049] Although this is not visible in [Fig.l], the rotor of the HP compressor 16 is connected to the rotor of the HP turbine by a high pressure shaft, and the rotor of the LP compressor 14 is connected to the rotor of the LP turbine by a low pressure shaft which passes through the high pressure shaft and which rotates a propulsion propeller, called a fan 23, located upstream of the gas generator 12 and which is surrounded by an annular casing called a fan casing 24.

[0050] The fan casing 24 is connected to the gas generator 12 by an intermediate casing 26 which comprises a central hub 28 and a series of radial arms 30 connecting the hub 28 to the fan casing 24.

[0051] The gas generator 12 defines a main annular vein V1 for the flow of a first air flow, called primary flow F1. The gas generator 12 is surrounded by a secondary annular vein V2 for the flow of a second air flow, called secondary flow F2.

[0052] The air flow F entering the fan 23 is divided into a part forming the primary flow FL. The air of this primary flow FL is compressed in the LP 14 and HP 16 compressors, then mixed with fuel and burned in the combustion chamber. The combustion gases of the primary flow are then expanded in the HP and LP turbines and finally flow into an exhaust nozzle.

[0053] The other part of the air flow entering the blower 23 forms the secondary flow F2 and is intended to be mixed with the primary flow F1 downstream of the nozzle.

[0054] A control device to which the invention is addressed is for example installed between the BP 14 and HP 16 compressors, in the zone ZI delimited by a dotted rectangle.

[0055] [Fig.2] illustrates a control device 30 of the prior art, as described in document FR-A1-3 082 562.

[0056] This device 30 comprises:

[0057] - a series of discharge doors 32 distributed around a first axis, which is the axis A, and each movable in pivoting relative to a second axis B tangent to a circumference centered on the axis A, and

[0058] - a system 34 for controlling the discharge doors 32 of the control device 30 for their synchronized pivoting around the B axes.

[0059] In the case shown, the control system 34 comprises at least one jack 36 and a control ring 38 centered on the axis A. The jack 36 transmits a movement to the control ring 38, and the control ring 38 is connected to each of the doors by linkages 40 which make it possible to drive the doors 30 in pivoting during the movement of the ring 38.

[0060] The prior art control devices have disadvantages described above and the present invention provides a new design of control device, one embodiment of which is schematically illustrated in [Fig.3].

[0061] The control device 50 according to the invention comprises:

[0062] - a series of discharge doors 52 distributed around a first axis A and movable each pivoting relative to a second axis B tangent to a circumference centered on the first axis A, and

[0063] - a control system 54 for the discharge doors 52 for their pivoting synchronized around the second B axes, this control system comprising at least an actuator such as a cylinder 56, comprising a fixed cylinder 58 and an actuator, such as a movable piston 60.

[0064] The particularity of the control device 50 is that its control system 54 is of the octopus type.

[0065] This control system 54 comprises a single first part 54a connected to the movable piston 60 and a second part 54b divided into several branches 62 which each extend between the first part 54a and the discharge doors 52.

[0066] The number of branches 62 is equal to the number of discharge gates 52 and the branches 62 are respectively connected to the discharge gates 52.

[0067] The control system 54 is configured to transform a translational or rotational movement of the movable piston 60 into a pivoting movement of the discharge doors 52.

[0068] [Fig. 3] shows several features of the control device 50 according to the invention, some of which are optional. Some of these features will be described in more detail below with reference to Figures 4 and following.

[0069] First, [Fig.3] shows an example of a configuration with a single cylinder 56 and four doors 52 but it is understood that the cylinder 56 can be connected to any number of doors 52 and for example to all the discharge doors 52. The number of cylinders 56 is also not limiting. The device 50 could for example comprise two cylinders 56 which are each connected to one half of the doors 52.

[0070] [Fig.4] for example shows the case where a jack 56 is connected to three doors 52.

[0071] The or each cylinder 56 comprises a fixed cylinder 58 and a movable piston 60. The cylinder 58 is preferably fixed to a casing 64 of the turbomachine, and in particular to the external periphery of this casing 64 in the case where this casing internally delimits the flow vein of the primary flow (see [Fig.l]). The piston 60 is movable in translation relative to the cylinder 58 and is therefore movable from a position retracted into the cylinder 58 to an extended or deployed position.

[0072] The discharge doors 52 are hinged on the casing 64 to be movable in pivoting relative to the axes B.

[0073] As seen in [Fig. 3], the casing 64 may comprise several supports 96 of the control system 54. These supports 96 comprise, for example, several arms 66 which extend outwards from the casing 64 and which comprise, at their free ends opposite the casing 64, elements 68 for fixing the control system 54, such as mounting collars.

[0074] Advantageously, the jack 56 and the multiplexing member 70 can be fixed on the same frame of the casing 64 in order to obtain the most compact assembly possible.

[0075] [Fig.3] shows that the first part 54a of the control system 54 can be connected to the branches 62 by a sliding multiplexing member 70.

[0076] The first part 54a preferably comprises a cable 72, for example flexible, which comprises a tubular sheath 74 inside which is capable of sliding a blade 76 of elongated shape, a first end 76a of which is connected to the movable piston 60, and a second opposite end 76b of which is connected to the branches 62, in particular by the multiplexing member 70.

[0077] Figures 5 and 6 show an example of a cable 72 that can be used in the context of the present invention. The blade 76 is guided in translation along and inside the sheath 74 by longitudinal ball bearings 78 or the like.

[0078] The sheath 74 may be semi-rigid (i.e. partly rigid and flexible along its length). The sheath 74 may be made by braiding wires in the manner of a sock, for example. The rolling elements of the bearings 78 may be balls, for example made of ceramic. The blade 76 may be made of ductile stainless steel to make it fusible in the event of extreme load, with a self-lubricating coating ensuring its sliding.

[0079] The operation of such a cable 72 is similar to that of a jack. By analogy with the cylinder of a jack, the sheath 74 of the cable 72 is fixed and by analogy with the piston of the jack, the blade 76 slides inside the sheath 74 and can transmit a traction or thrust force.

[0080] If we refer again to [Fig. 3], we understand that the sheath 74 of the cable 72 is carried by the casing 64 and can in particular be held by the aforementioned fixing elements 68. The blade 76 has its first end 76a which is connected to the piston 60 of the jack 56, and its second opposite end 76b which is connected to the multiplexing member 70. The deployment of the piston 60 of the jack 56 causes the displacement of the blade 76 in its sheath 74 on the side opposite the jack 56, and the retraction of the piston 60 into the cylinder 58 of the jack 56 causes the displacement of the blade 76 in its sheath towards the jack 56. The multiplexing member 70 transmits its movements to each of the branches 62 in a synchronized and homogeneous manner.

[0081] Figures 7 to 10 show examples of connection of the piston 60 of the jack 56 to the first part 54a and in particular to the blade 76.

[0082] Figures 8 and 9 show for example that the end 76a of the blade 76 can be engaged in a slot 78 of the piston 60 and immobilized in this slot 78 by screwing a nut 80 around this end 76a. The end 76a of the blade 76 can comprise hollow or projecting elements 82 which cooperate by engagement with complementary projecting or hollow elements of the slot 78, in order to better secure the blade 76 and the piston 60. The nut 80 can comprise notches / slots making it possible to ensure anti-rotation thanks to tongue washers folded down in cooperation with the notches of the nut 80.

[0083] [Fig. 10] shows a variant in which the connection of the piston 60 of the jack 56 to the blade 76 is swiveling. The end 76a of the blade 76 is engaged in a slot of a sphere 84 which is mounted in a swiveling manner in a housing of the piston 60.

[0084] The blade 76 must be able to rotate freely on its axis. The swivel connection of [Fig. 10] is therefore advantageous. This assembly will preferably leave a slight assembly play so as not to block the sphere 84 with respect to its antagonist.

[0085] Other assemblies of the cylinder 60 to the blade 72 are possible such as crimping or riveting if the configuration of the system allows it.

[0086] Other swivel solutions can be considered, such as the use of a crimped ball joint with an inner ring adapted to receive the blade of the flexible control or to accommodate the piston of the cylinder.

[0087] The particularity of the control cable 72 is that it is capable of transmitting forces resulting from the octopus, in both directions (push / pull). It will therefore generally have a diameter greater than the unit branches making up the octopus.

[0088] As mentioned above, the second part 54b of the system 54 comprises a multitude of branches 62.

[0089] As shown in Figures 3 and 11, each of these branches 62 comprises a rectilinear portion 62a located on the side of the first part 54a, and a non-rectilinear portion 62b located on the side of the discharge doors 52.

[0090] The straight portion 62a of each branch 62 may be rigid or flexible, and the non-straight portion 62b of each branch 62 may be flexible. In other words, the rigidity of each branch 62 may vary along its length.

[0091] The rectilinear portions 62a of the branches 62 are preferably joined together and secured to each other, for example via fasteners of the Colson® type for example. The non-rectilinear portions 62b of the branches 62 may be independent of each other in order to facilitate their connection to the doors 52.

[0092] Each of the branches 62 may comprise a cable 72', preferably flexible, which comprises a tubular sheath 74' inside which an elongated blade 76' is capable of sliding. It is therefore understood that each of the branches 62 may have a configuration similar to that of the first part 54a of the system and illustrated in FIGS. 5 and 6.

[0093] A first end 76a' of the blade 76' of each branch 62 is connected

[0094] to the multiplexing member 70, preferably by a ball joint 85.

[0095] A second opposite end 76b' of the blade 76' of each branch 62 is connected to the corresponding discharge door 52.

[0096] The multiplexing member 70 shown very schematically in [Fig. 3] comprises for example a plate 86 which is connected to the end 76b of the blade 76 of the first part 54a as well as to the ends 76a' of the blades 76' of the branches 62. The plate 86 is guided in translation by one or more guides 88 which are carried by the casing 64.

[0097] Figures 12a and 12b show an example of a connection between a branch 62 and a discharge door 52.

[0098] The blade 76' of each of the branches 62 has its end 76b' which is connected to the corresponding discharge door 52 by a chain 90 and a connecting rod 92.

[0099] As its name indicates, the 90 chain is a small chain composed of links articulated to each other and having in appearance a shape similar to a part of a bicycle chain.

[0100] The chain 90 has an end 90a connected to the end 76b of the blade 76 and an opposite end 90b connected to an end 92a of the connecting rod 92, an opposite end 92b of which is connected to the discharge door 52.

[0101] The chain 90 is movable in translation inside a sheath 94.

[0102] In the example shown in Figures 12a-12b and 13a-13b, the sheath 94 is bent. The elbow can form an angle greater than or equal to 90° and less than 180°.

[0103] In the variant of figures 14a-14b, the sheath is almost rectilinear.

[0104] The chain 90 may comprise spherical rolling rollers or fixed sliding rollers facilitating its movement in the sheath 94.

[0105] At least one of the ends 92a, 92b of the connecting rod 92 may comprise a ball joint. At least one of the ends 90a, 90b of the chain 90 may comprise a ball joint.

[0106] Figures 13a to 14b further show that the control system comprises a structural attachment positioned directly upstream of the door 52 to be actuated. The attachment here comprises a support fitting 96 made integral with the aforementioned casing 64 preferably via bolted connections.

[0107] The fitting 96 can accommodate the aforementioned sheath 94 and / or directly the end of the sheath 74'.

[0108] The fitting 96 is preferably mounted in a cantilevered manner, and fixed by at least two screws 98. It will be aligned with the direction of the piston 60 for example. Other fixing points can be added to increase the stiffness of the support (fixing on an additional flange if necessary for example) or the use of specific materials (forged or composite for example).

[0109] The fitting 96 can also support and guide the branches 62 traveling towards the other doors 52, for example by a cylindrical cutout intended to accommodate the branches or to retain them.

[0110] [Fig. 15] shows an example of connection of the end 76b' of the blade 76' of each branch 62 to the end of the corresponding chain 90. The end 76b' of the blade 76' can be engaged in a slot 78' of the end 90a of the chain 90 and immobilized in this slot 78' by screwing a nut 80' around this end 76b'. The end 76b' of the blade 76' may comprise hollow or projecting elements 82' which cooperate by engagement with complementary projecting or hollow elements of the slot 78', in order to better secure the blade 76' and the chain 90 as mentioned above with reference to [Fig.9]. The nut 80' may comprise notches / slots making it possible to ensure anti-rotation thanks to washers with folded tabs in cooperation with the notches of the nut 80'.

[0111] The control device 50 according to the invention is particularly suitable for transmitting equivalent forces in both directions (thrust and traction). Blade technology is a preferred embodiment of the octopus but other configurations are possible. This octopus could be made of a single, inseparable piece, to facilitate its assembly.

[0112] The present invention provides several advantages, including:

[0113] This architecture makes it possible to dispense with an area dedicated to the ring 38 of the prior art ([Fig.2]) over 360°. The routing of flexible controls can be done in unused, or non-dedicated, volumes.

[0114] The jack can be positioned / oriented / fixed in the most available, most accessible volumes and the most favorable positions for its support.

[0115] The interest may also be to reduce the number of fire zones or to redraw their contours.

[0116] An advantage of installing the cylinder in colder areas opens up the possibilities of using EHA (electro-hydraulic actuator) or electric type actuators.

[0117] The service life of flexible blade or link drives is more efficient than dry bearing mechanisms with friction. The product specification will be for the life of the turbomachine

[0118] Overall accuracy is improved by reducing the number of intermediate bearings (and therefore the internal clearances of each of these connections) between the cylinder and each final door.

[0119] Specific accuracies are improved, with a blade control having an accuracy of the order of 1%.

[0120] This can result in either improving the precision of door opening, or accepting less precise actuators and therefore simpler, less expensive, lighter technologies.

[0121] It is estimated that the overall cost of the function is reduced thanks to the opening of collateral opportunities (simplification of the casing, reduction in the number of parts in the kinematics, removal of fire constraints from certain parts, use of electric actuators, etc.).

Claims

Claims

1. Device (50) for controlling discharge doors (52) for an aircraft turbomachine (10), this device (50) comprising: - a series of discharge doors (52) distributed around a first axis (A) and each movable in pivoting relative to a second axis (B) tangent to a circumference centered on the first axis (A), and - a system (54) for controlling the discharge doors (52) with a view to their synchronized pivoting around their second axes (B), this control system (54) comprising at least one actuator such as a jack (56), comprising for example a fixed cylinder (58) and a movable piston (60), characterized in that the control system (54) is of the octopus type and comprises a first single part (54a) connected to the actuator (56), and in particular to the movable piston (60), and a second part (54b) divided into several branches (62) which each extend between the first part (54a) and the discharge doors (52),the number of branches (62) being equal to the number of discharge doors (52) and the branches (62) being respectively connected to the discharge doors (52), the control system (54) being configured to transform a translational movement of the actuator, and in particular of the movable piston (60), into a pivoting movement of the discharge doors (52).,

2. Device (50) according to claim 1, in which the first part (54a) is connected to the branches (62) by a slide multiplexing member (70).

3. Device (50) according to claim 1 or 2, in which the first part (54a) comprises a cable (72) which comprises a tubular sheath (74) inside which is capable of sliding an elongated blade (76) of which a first end (76a) is connected to the actuator (56), and in particular to the movable piston (60), and of which a second opposite end (76b) is connected to the branches (62).

4. Device (50) according to all of claims 2 and 3, in which the second end (76b) of the blade (76) is connected to the multiplexing member (70) which is connected to each of the branches (62).

5. Device (50) of claim 3 or 4, wherein the first end (76a) of the blade (76) is connected to the actuator (56) by being engaged in a slot (78) of the actuator (56), and in particular of the piston (60), and in being immobilized in this slot (58) by cooperation of shapes and screwing of a nut (80) around this end (76a).

6. Device (50) according to one of the preceding claims, in which each of the branches (62) comprises a rectilinear portion (62a) located on the side of the first part (54a), and a non-rectilinear portion (62b) located on the side of the discharge doors (52), or each of the branches (62) comprises at least two rectilinear portions located on the side of the first and second parts (54a-54b) and a rectilinear and / or non-rectilinear intermediate portion.

7. Device (50) according to claim 6, wherein the straight portion (62a) of each branch (62) is rigid or flexible, and the non-straight portion (62b) of each branch (62) is flexible.

8. Device (50) according to one of the preceding claims, in which each of the branches (62) comprises a cable (72'), preferably flexible, which comprises a tubular sheath (74') inside which an elongated blade (76') is capable of sliding.

9. Device (50) according to claim 8, dependent on claim 2 or 4, in which the blade (76') of each of the branches (62) has an end (76a') which is connected to the multiplexing member (70) by a ball joint (85).

10. Device (50) according to claim 8 or 9, wherein the blade (76') of each of the branches (62) has one end which is connected to the corresponding discharge door (52) by a ball joint.

11. Device (50) according to one of claims 8 to 10, in which the blade (76') of each of the branches (62) has an end which is connected to the corresponding discharge door (52) by a chain (90) and / or a connecting rod (92).

12. Device (50) according to claim 11, in which the chain (90) is movable in translation, for example by rolling, inside a sheath (94), preferably bent.

13. Device (50) according to claim 11 or 12, wherein at least one of the ends (92a, 92b) of the link (92) comprises a ball joint, and / or at least one of the ends (90a, 90b) of the chain (90) comprises a ball joint.

14. Device (50) according to one of the preceding claims, in which it further comprises an annular casing (64) which extends around the first axis (A), as well as supports (96) of the control system (54) which are carried by the casing (64).

15. Device (50) according to the preceding claim, in which the supports (96) comprise several arms (66) which extend outwardly from the casing (64) and which comprise at their free ends opposite the casing fixing elements (68), such as mounting collars.

16. Turbomachine (10) for an aircraft, comprising at least one device (50) according to one of the preceding claims.

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