A miniature axisymmetric vectoring nozzle suitable for small aircraft

Abstract

The application discloses a micro axis-symmetrical vector nozzle suitable for a small aircraft and belongs to the field of aeroengines.The nozzle comprises a fixed support, a nozzle, a nozzle support and a transmission assembly.The fixed support comprises a sleeve and two side plates, the sleeve is sleeved on an engine body, the two side plates are symmetrically fixed on the two sides of the sleeve, the nozzle is fixedly connected with the nozzle support, and the nozzle support is coaxially connected with the sleeve through the side plates; one end of the side plate is fixed with a positioning pin for installing the transmission assembly, and the other end is provided with a pin hole for being hinged with cylindrical bosses on the two sides of the nozzle support; one set of the transmission assembly is installed on each of the two side plates, the transmission assembly comprises a first short connecting rod, a long connecting rod, a second short connecting rod and a gear, a rudder is installed on the side plate, the rudder drives the gear to rotate, drives the first short connecting rod to rotate, further drives the long connecting rod to rotate, drives the second short connecting rod to rotate and drives the nozzle support to rotate, and axial deflection of the nozzle is realized.

Description

Technical Field

[0001] This invention belongs to the field of aero-engines, and specifically relates to a micro axisymmetric vector nozzle suitable for small aircraft. Background Technology

[0002] Thrust vectoring technology can greatly expand the operational envelope of an aircraft, improve its safety, and significantly enhance its survivability and tactical effectiveness. It has become a key technology in the aviation field, and it is now a consensus that advanced aircraft must be equipped with thrust vectoring engines.

[0003] Small aircraft, represented by unmanned combat aerial vehicles (UCAVs), possess military advantages such as high stealth, high maneuverability, high intelligence, and low cost, and their importance in combat is gradually becoming more prominent, making them an important component of aviation weaponry. As the modern air combat environment becomes increasingly complex, higher demands are being placed on the performance of small aircraft, such as high-performance, high-combat-capability UAVs / swarms.

[0004] Thrust vectoring technology has been proven in large fighter jets to significantly improve stealth and maneuverability, making its application a crucial trend in the development of unmanned combat aircraft. Vectoring nozzles are mainly categorized into two-dimensional vectoring nozzles, axisymmetric thrust vectoring nozzles, and three-bearing deflection vectoring nozzles. Extensive research both domestically and internationally has revealed that axisymmetric vectoring nozzles exhibit lower aerodynamic loads, simpler control mechanisms, and more compact profiles, offering advantages over two-dimensional and three-bearing vectoring nozzles. This is the result of long-term optimization of thrust vectoring technology.

[0005] Current axisymmetric vectoring nozzles are all used in large fighter jets. Their actuation mechanisms are complex, assembly is difficult, and they use hydraulic transmission. Limited by weight and size, they cannot meet the vector propulsion requirements of small aircraft. The development of miniature axisymmetric vectoring nozzles can be applied to high-speed, high-maneuverability small aircraft, with clear application prospects and urgent engineering needs. Summary of the Invention

[0006] The technical problem to be solved:

[0007] To overcome the shortcomings of existing technologies, this invention provides a micro axisymmetric vector nozzle suitable for small aircraft. The nozzle and nozzle support are fixedly connected as a whole. The sleeve of the fixed support is fitted onto the engine. Transmission components located on both sides of the fixed support connect the sleeve and the nozzle support. A servo is mounted on the side plate of the fixed support and meshes with the gear of the transmission component. The servo drives the transmission component to achieve ±20° axial deflection of the nozzle. This invention solves the problem that existing axisymmetric vector nozzles are not suitable for high-speed, high-maneuverability small aircraft. Its structure is simple and will not impose a weight burden on small aircraft. At the same time, the design of the inner diameter nozzle can reduce the infrared signature of the aircraft.

[0008] The technical solution of the present invention is: a micro axisymmetric vector nozzle suitable for small aircraft, comprising a fixed bracket, a nozzle 1, a nozzle support 2, and a transmission assembly;

[0009] The fixed bracket includes an annular sleeve 3 and two side plates 33. The sleeve 3 is fitted onto the engine body by fasteners. One end of the two side plates 33 is symmetrically fixed to both sides of the sleeve 3, and the other end extends to the nozzle support 2. One end of the nozzle 1 is coaxially fixed to the nozzle support 2. The nozzle support 2 is coaxially connected to the sleeve 3 through the two side plates 33, and the nozzle support 2 is hinged to the side plates 33.

[0010] The horizontal center line of the side plate 33 is located on the horizontal plane where the axis of the sleeve 3 is located. The side plate 33 is fixed with a positioning pin 34 at the connection end with the sleeve 3, and a pin hole 36 is provided at the other end. The axis of the positioning pin 34 and the pin hole 36 is located on the horizontal center line of the side plate 33. The nozzle support 2 is symmetrically fixed with columnar bosses 22 on both sides. The nozzle support 2 is hinged to the side plate 33 through the columnar bosses 22 and the pin hole 36.

[0011] Two sets of the aforementioned transmission components are symmetrically installed on two side plates 33. The transmission components include a first short connecting rod 41, a long connecting rod 42, a second short connecting rod 43, and a gear 44. The gear 44 is fixed to one end of the first short connecting rod 41 and is hinged to a positioning pin 34 at one end of the side plate 33 as a whole. The other end of the first short connecting rod 41 is hinged to one end of the long connecting rod 42, the other end of the long connecting rod 42 is hinged to one end of the second short connecting rod 43, and the other end of the second short connecting rod 43 is fixedly connected to the columnar boss 22.

[0012] Servo motor 5 is mounted on side plate 33. The drive gear 51 of servo motor 5 meshes with gear 44. By driving gear 44 to rotate through servo motor 5, the first short connecting rod 41 is driven to rotate, which in turn drives the long connecting rod 42 to drive the second short connecting rod 43 to rotate, thereby rotating the nozzle support 2 and realizing the axial deflection of nozzle 1.

[0013] A further technical solution of the present invention is: the nozzle 1 is a nozzle with a constant inner diameter, the ratio of its inner diameter to the nozzle inlet diameter of the installed engine is between 1 and 1.2, and the ratio of the length of the nozzle 1 to the length of the installed engine nozzle is between 1.9 and 2.1.

[0014] A further technical solution of the present invention is: the nozzle support 2 is a ring-shaped support, coaxially fitted to one end of the nozzle 1, and the nozzle 1 and the nozzle support 2 are welded and fixed by two support columns 21 arranged radially along the nozzle support 2. The two support columns 21 are coaxial, and their axes are perpendicular to the horizontal plane where the axis of the nozzle support 2 is located.

[0015] A further technical solution of the present invention is as follows: the end of the columnar boss 22 is a cross pin 221, and one end of the second short connecting rod 43 is provided with a cross hole that matches the cross pin 221. The second short connecting rod 43 is fixed to rotate around the cross pin 221 by fitting it into the cross hole; the middle part of the columnar boss 22 is provided with a smooth cylindrical section 222, and the pin hole 36 at one end of the side plate 33 is fitted into the cylindrical section 222 to realize the hinge connection between the side plate 33 and the nozzle bracket 2 and the second short connecting rod 43.

[0016] A further technical solution of the present invention is that the hinge between the first short connecting rod 41, the long connecting rod 42, and the second short connecting rod 43 is achieved by a pin 45 in conjunction with a snap ring 46.

[0017] A further technical solution of the present invention is that the axial deflection angle of the nozzle 1 is ±20°.

[0018] A further technical solution of the present invention is: the sleeve 3 is composed of a left half-ring sleeve 31 and a right half-ring sleeve 32, which are fixed to the engine body by high-temperature resistant bolts.

[0019] A further technical solution of the present invention is: the gear 44 is fixed to the outer side of one end of the first short connecting rod 41 by welding, and the central shaft hole of the gear 44 is connected to the hinge hole at that end of the first short connecting rod 41 and the two holes are of equal diameter.

[0020] A further technical solution of the present invention is: the servo motor 5 is mounted on the side plate 33 by the mounting plate 35, the side plate 33 is provided with a horizontal mounting groove in the middle, the mounting plate 35 is inserted and fixed in the horizontal mounting groove, the mounting plate 35 is provided with a connecting hole, and the servo motor 5 is fixed by fasteners passing through the connecting hole.

[0021] A further technical solution of the present invention is: the servo motor 5 is an electric servo motor, the servo motor 5 is connected to the UAV control system, and receives commands from the UAV control system to actuate. The rated torque of the servo motor 5 is greater than the torque required for the nozzle 1 to deflect to the maximum angle.

[0022] Beneficial effects

[0023] The beneficial effects of the present invention are as follows: The present invention provides a micro axisymmetric vector nozzle suitable for small aircraft. The nozzle and the nozzle support are fixedly connected as a whole. The sleeve of the fixed support is fitted onto the engine. The transmission components located on both sides of the fixed support connect the sleeve and the nozzle support. The electric servo is installed on the side plate of the fixed support and meshes with the gear of the transmission component. The transmission component is driven by the electric servo to achieve ±20° axial deflection of the nozzle.

[0024] This invention utilizes the ejection effect of a nozzle with a constant inner diameter to mix the high-temperature exhaust with cold air, thereby reducing the infrared signature of the aircraft. The ratio of the nozzle's inner diameter to the inlet diameter of the engine's nozzle is between 1 and 1.2, and the ratio of the nozzle length to the engine's nozzle length is between 1.9 and 2.1, resulting in optimal thrust vectoring performance.

[0025] The fixed bracket of the present invention adopts a pair of left and right half-ring sleeves and a side plate structure respectively fixed to the left and right half-ring sleeves, which makes the vector nozzle easy to install in a suitable position on the engine fuselage and easy to disassemble and assemble, and can meet different flight requirements.

[0026] This invention coaxially fixes the equal-diameter nozzle to the nozzle support, and fixes the gear and the first short connecting rod. The gear and the first short connecting rod are hinged as a whole to a positioning pin fixed at one end of the side plate. The nozzle support is hinged to the other end of the side plate through a columnar boss. One end of the second short connecting rod is circumferentially fixed to the cross pin at the end of the columnar boss. The first short connecting rod, the long connecting rod, and the second short connecting rod are hinged together, so that the side plate, the first short connecting rod, the long connecting rod, and the second short connecting rod form a linkage mechanism. By driving the gear with an electric servo motor, the equal-diameter nozzle can be deflected ±20° under the action of the linkage mechanism. The various structures cooperate with each other, greatly reducing the complexity and weight of the actuation system without reducing the thrust vector performance of the nozzle.

[0027] This invention ingeniously utilizes a simple linkage mechanism combined with a nozzle of equal inner diameter to construct an axisymmetric vectoring nozzle suitable for small aircraft. Compared to conventional axisymmetric vectoring nozzles, this invention achieves precise angle deflection while maintaining a simple structure and light weight, thus not placing a weight burden on small aircraft. Furthermore, it does not require alteration of the original engine nozzle structure; simple assembly enables the engine to acquire vectoring capabilities, thereby improving the maneuverability of small aircraft. This invention solves the problems of existing axisymmetric vectoring nozzles being complex in structure, have numerous parts, are heavy, and are unsuitable for high-speed, high-maneuverability small aircraft. Attached Figure Description

[0028] Figure 1 This is an overall axial view of the axisymmetric vector nozzle of the present invention;

[0029] Figure 2 This is the overall front view of the axisymmetric vector nozzle of the present invention;

[0030] Figure 3 This is a rear view of the axisymmetric vector nozzle of the present invention.

[0031] Figure 4 This is the left half of the axis view of the fixed bracket;

[0032] Figure 5 This is a schematic diagram showing the meshing of the drive gear of the electric servo motor with the gear fixed to the first short connecting rod;

[0033] Figure 6 This is a right view of the overall axisymmetric vector nozzle of the present invention;

[0034] Figure 7 A sectional view showing the installation relationship of the fixed bracket being hinged to the first short connecting rod and gear via a locating pin;

[0035] Figure 8 This is an overall axial view of the nozzle support and the nozzle with the same inner diameter;

[0036] Figure 9 Right view of the nozzle support and the nozzle with equal inner diameter as a whole;

[0037] Figure 10 A structural diagram showing the first short connecting rod and the gear fixed together as a whole;

[0038] Figure 11 This is a structural diagram of a long connecting rod;

[0039] Figure 12 This is a schematic diagram of the downward deflection of the axisymmetric vector nozzle of the present invention;

[0040] Figure 13 This is a schematic diagram of the upward deflection of the axisymmetric vector nozzle of the present invention;

[0041] Figure 14 Axial view of a JETCAT P400 engine;

[0042] Figure 15 A axial view of a JETCAT P400 engine equipped with the axisymmetric vector nozzle of the present invention.

[0043] Explanation of reference numerals in the attached figures:

[0044] 1. Nozzle 2. Nozzle bracket 21. Support column 22. Columnar boss 221. Cross pin 222. Cylindrical section 3. Hoop 31. Left half ring hoop 32. Right half ring hoop 33. Side plate 34. Positioning pin 35. Mounting plate 36. Pin hole 41. First short connecting rod 42. Long connecting rod 43. Second short connecting rod 44. Gear 45. Pin shaft 46. Snap ring 5. Servo motor Detailed Implementation

[0045] The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the invention, and should not be construed as limiting the invention.

[0046] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0047] Example:

[0048] See Figure 1-4 The present invention provides a micro axisymmetric vector nozzle suitable for small aircraft, comprising a fixed bracket, a nozzle 1, a nozzle support 2, and a transmission assembly;

[0049] The fixed bracket includes an annular sleeve 3 consisting of a pair of left half-ring sleeves 31 and a right half-ring sleeve 32, and two side plates 33, one end of which is fixed to the left half-ring sleeve 31 and the right half-ring sleeve 32 respectively. The sleeve 3 is fixed to a suitable position on the engine body by high-temperature resistant bolts. The two side plates 33 are symmetrically arranged on both sides of the sleeve 3. The horizontal center line of the side plates 33 is located on the horizontal plane where the axis of the sleeve 3 is located. A positioning pin 34 is fixed on the outer side of the connection end between the side plate 33 and the sleeve 3 for installing the transmission component. The other end is provided with a pin hole 36 for hinged connection with the nozzle bracket 2. The axis of the positioning pin 34 and the pin hole 36 is located on the horizontal center line of the side plate 33.

[0050] The nozzle 1 is a constant inner diameter nozzle, with the ratio of its inner diameter to the nozzle inlet diameter of the installed engine being between 1 and 1.2. The ratio of the length of the nozzle 1 to the length of the installed engine nozzle is between 1.9 and 2.1. The nozzle 1 is fixed to the nozzle support 2, forming a symmetrical structure. Specifically, the nozzle support 2 is a ring-shaped support, coaxially fitted onto one end of the nozzle 1. The nozzle 1 and the nozzle support 2 are welded and fixed together by two support columns 21 arranged radially along the nozzle support 2. The two support columns 21 are coaxial, with their axis perpendicular to the horizontal plane containing the axis of the nozzle support 2. Two columnar bosses 22 are symmetrically fixed on both sides of the nozzle support 2, specifically on the horizontal plane containing its axis. These bosses are used to hinge with pin holes 36 at one end of the side plates 33 on both sides, so that the nozzle 1 is located behind the original engine nozzle and wraps around the rear half of the original nozzle. The nozzle support 2 is also horizontally coaxial with the sleeve 3.

[0051] The transmission assembly consists of two sets, symmetrically installed on both sides of the fixed bracket. One end is installed on the positioning pin 34 of the fixed bracket, and the other end is installed on the columnar boss 22 of the nozzle bracket 2. Specifically, the transmission assembly includes a first short connecting rod 41, a long connecting rod 42, a second short connecting rod 43, and a gear 44. See also... Figure 10 Gear 44 is welded to the outer side of one end of the first short connecting rod 41. Gear 44 and the first short connecting rod 41 are hinged as a whole to the positioning pin 34 at one end of the side plate 33. The central shaft hole of gear 44 is connected to the hinge hole at that end of the first short connecting rod 41 and the holes are equal in diameter and coaxial. The other end of the first short connecting rod 41 is hinged to one end of the long connecting rod 42, and the other end of the long connecting rod 42 is hinged to one end of the second short connecting rod 43. The other end of the second short connecting rod 43 is fixedly connected to the columnar boss 22. In this embodiment, the long connecting rod 42 and the side plate 33 have the same working length, which is determined by the position where the nozzle 1 is to be installed. The first short connecting rod 41 and the second short connecting rod 43 have the same working length, which must meet the ±20° deflection requirement of the nozzle 1 and leave enough space for the servo motor 5.

[0052] See Figure 1 , 6 The hinge between the first short link 41, the long link 42, and the second short link 43 is achieved through a pin 45 and a retaining circlip 46. The axial position of the hinge is limited by the cap of the pin 45 and the retaining circlip 46 installed in the retaining groove of the pin 45. (See reference...) Figure 4 , Figure 7 The diameter of the middle section of the positioning pin 34 is slightly smaller than that of the two ends. The gear 44 and the first short connecting rod 41 are fitted onto the middle section by liquid nitrogen cold pressing technology to achieve hinge connection and axial positioning.

[0053] See also Figure 8 , 9 The end of the columnar boss 22 is a cross pin 221, and the middle is provided with a smooth cylindrical section 222. The pin hole 36 at one end of the side plate 33 is fitted into the cylindrical section 222 to realize the hinge connection between the side plate 33 and the nozzle bracket 2. The side plates 33 on both sides are installed one-to-one with the columnar bosses 22 on both sides. The end of the second short connecting rod 43 connected to the columnar boss 22 is provided with a cross hole that matches the cross pin 221. The second short connecting rod 43 is fixed by rotating around the cross pin 221 through the cross hole and also makes the side plate 33 and the second short connecting rod 43 hinged.

[0054] See Figure 4 , 5The servo motor 5 is mounted on the side plate 33 via a mounting plate 35. A horizontal mounting groove is provided in the middle of the side plate 33, and the mounting plate 35 is inserted and fixed into the horizontal mounting groove. The mounting plate 35 has multiple connecting holes, through which fasteners are passed to fix the servo motor 5 to the side plate 33. The drive gear 51 of the servo motor 5 meshes with a gear 44 fixed to the first short connecting rod 41. The servo motor 5 drives the gear 44 to rotate, causing the first short connecting rod 41 to rotate, which in turn pushes the long connecting rod 42, causing the long connecting rod 42 to drive the second short connecting rod 43 to rotate. The cross hole of the second short connecting rod 43 engages with the cross pin 221 at the end of the columnar boss 22 fixed to the nozzle support 2 for circumferential limiting, thereby driving the nozzle support 2 to rotate and achieving axial deflection of the nozzle 1. The servo motor 5 used in this embodiment is an electric servo motor, which is connected to the UAV control system and receives commands from the UAV control system to operate. Specifically, the electric servo motor in this embodiment consists of a motor, transmission components, and a clutch, and operates by receiving downlink signals from the control board controlled by the 51 single-chip microcontroller. When a specific computer program controls the motor via a data cable, the electric servo rotates under complete control of the computer signal. The rated torque of the electric servo is greater than the torque required for the nozzle to deflect at its maximum angle (20°). Simultaneously, the number of teeth and the tooth diameter ratio of gear 44 depend on the drive gear 51 used in the selected electric servo to ensure optimal meshing and thus stable torque transmission.

[0055] See figure Figure 1 , 12 13. The nozzle 1, driven by the servo motor 5, achieves an axial deflection angle of ±20°. (See reference...) Figure 1 When nozzle 1 is in its normal state, the long connecting rod 42 is in a horizontal position, and the first short connecting rod 41 and the second short connecting rod 43 are both perpendicular to the long connecting rod 42. At this time, nozzle 1 has no horizontal vector. (See also...) Figure 12 When nozzle 1 is in the downward vectoring state, the gears 44 and the first short connecting rod 41, symmetrically arranged on both sides of the fixed bracket, rotate clockwise under the drive of the servo motor 5. The long connecting rods 42 on both sides move horizontally to the right, causing the second short connecting rod 43 to rotate clockwise, thereby causing nozzle 1 to deflect downwards, resulting in a downward jet direction and thus an upward vector thrust. (See also...) Figure 13 When the nozzle 1 is in the upward vector state, the gears 44 and the first short connecting rod 41, which are symmetrically arranged on both sides of the fixed bracket, rotate counterclockwise under the drive of the servo motor 5. The long connecting rods 42 on both sides move horizontally to the left, causing the second short connecting rod 43 to rotate counterclockwise, which in turn causes the nozzle 1 to deflect upward, and the jet direction is upward, thus obtaining a downward vector thrust.

[0056] See Figure 14 , 15The axisymmetric vector nozzle of this invention is fixed to a suitable position on the fuselage of the JETCATP400 engine by a high-temperature resistant bolt set. The servo motor 5 drives the gear 44 to rotate, which in turn drives the linkage mechanism formed by the side plate 33, the first short connecting rod 41, the long connecting rod 42, and the second short connecting rod 43. This causes the nozzle 1 to deflect at an angle, and the main flow passing through the original engine nozzle impacts the inner wall of the constant-diameter nozzle 1. The deflected nozzle 1 exerts a force on the main flow, and according to the law of conservation of momentum, the incoming flow is deflected, thereby generating a thrust vector. Due to the ejector effect of the constant-diameter nozzle 1, cool air flows through the gap between the vector nozzle 1 and the original engine nozzle and mixes with the high-temperature main flow, which not only cools the wall of the nozzle 1 but also reduces the temperature of the exhaust flow to a certain extent, shielding the high-temperature turbine components and reducing the infrared signature of the aircraft.

[0057] Conventional axisymmetric vectoring nozzles convert the linear displacement of the actuator cylinder into radial rotation of the scale-like nozzles around a hinge at their front end through an adjustment mechanism, thereby changing the throat area. This is achieved using either an integral adjustment plate with a ball joint or a segmented adjustment plate with a staggered "+" shaped hinge. Due to the presence of multiple actuating and adjusting components, the structure is complex, difficult to adjust, and heavy, making it completely unsuitable for mounting in the micro-engines of UAVs. This invention achieves nozzle deflection through a simple linkage mechanism, realizing vector propulsion of the engine, improving the combat capability and survivability of small aircraft. Its structure is simple, easy to disassemble, lightweight, and inexpensive, without adding weight burden to small aircraft. Furthermore, the constant inner diameter nozzle design reduces the infrared signature of the aircraft.

[0058] This invention utilizes a designed micro-axisymmetric vector nozzle aerodynamic profile and performs CFD numerical simulations. The ratios of the nozzle inner diameter to the original engine nozzle inlet diameter are set to 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, and 1.4, respectively, and the ratios of the nozzle length to the original engine nozzle length are set to 1.8, 1.9, 2.0, 2.1, and 2.2, respectively. The simulation results are processed to obtain thrust performance parameters such as thrust coefficient, thrust vector angle, and total pressure recovery coefficient. It is found that a ratio of the nozzle inner diameter to the original engine nozzle inlet diameter (for nozzles with the same inner diameter fixed to the nozzle support) between 1 and 1.2, and a ratio of the nozzle length to the original engine nozzle length between 1.9 and 2.1, yields better thrust vector performance.

[0059] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention without departing from the principles and spirit of the present invention.

Claims

1. A micro axisymmetric vector nozzle suitable for small aircraft, characterized in that: Includes a fixed bracket, a nozzle (1), a nozzle bracket (2), and a transmission assembly; The fixed bracket includes an annular sleeve (3) and two side plates (33). The sleeve (3) is fitted onto the engine body with fasteners. One end of the two side plates (33) is symmetrically fixed to both sides of the sleeve (3), and the other end extends to the nozzle bracket (2). One end of the nozzle (1) is coaxially fixed to the nozzle bracket (2). The nozzle bracket (2) is coaxially connected to the sleeve (3) through the two side plates (33). The nozzle bracket (2) is hinged to the side plates (33). The horizontal center line of the side plate (33) is located on the horizontal plane where the axis of the sleeve (3) is located. The side plate (33) is fixed with a positioning pin (34) at the connection end with the sleeve (3), and a pin hole (36) is provided at the other end. The axis of the positioning pin (34) and the pin hole (36) is located on the horizontal center line of the side plate (33). The nozzle support (2) is symmetrically fixed with columnar bosses (22) on both sides. The nozzle support (2) and the side plate (33) are hinged through the columnar bosses (22) and the pin hole (36). Two sets of the transmission components are symmetrically installed on two side plates (33). The transmission components include a first short connecting rod (41), a long connecting rod (42), a second short connecting rod (43), and a gear (44). The gear (44) is fixed to one end of the first short connecting rod (41). The gear (44) and the first short connecting rod (41) are hinged together as a whole to a positioning pin (34) at one end of the side plate (33). The other end of the first short connecting rod (41) is hinged to one end of the long connecting rod (42). The other end of the long connecting rod (42) is hinged to one end of the second short connecting rod (43). The other end of the second short connecting rod (43) is fixedly connected to a columnar boss (22). The servo motor (5) is mounted on the side plate (33). The drive gear (51) of the servo motor (5) meshes with the gear (44). The servo motor (5) drives the gear (44) to rotate, which drives the first short connecting rod (41) to rotate, and then pushes the long connecting rod (42) to drive the second short connecting rod (43) to rotate, so that the nozzle support (2) rotates, thereby achieving the axial deflection of the nozzle (1).

2. The micro axisymmetric vector nozzle suitable for small aircraft according to claim 1, characterized in that: The nozzle (1) is a nozzle with a constant inner diameter. The ratio of its inner diameter to the nozzle inlet diameter of the engine is between 1 and 1.2, and the ratio of the length of the nozzle (1) to the length of the engine nozzle is between 1.9 and 2.

1.

3. The micro axisymmetric vector nozzle suitable for small aircraft according to claim 1, characterized in that: The nozzle support (2) is a ring-shaped support, coaxially fitted to one end of the nozzle (1), and the nozzle (1) and the nozzle support (2) are welded and fixed by two support columns (21) arranged radially along the nozzle support (2). The two support columns (21) are coaxial, and their axis is perpendicular to the horizontal plane where the axis of the nozzle support (2) is located.

4. The micro axisymmetric vector nozzle suitable for small aircraft according to claim 1, characterized in that: The end of the columnar boss (22) is a cross pin (221). One end of the second short connecting rod (43) is provided with a cross hole that matches the cross pin (221). The second short connecting rod (43) is fixed to rotate around the cross pin (221) by fitting the cross hole into the cross pin (221). The middle part of the columnar boss (22) is provided with a smooth cylindrical section (222). The pin hole (36) at one end of the side plate (33) is fitted into the cylindrical section (222) to realize the hinge connection between the side plate (33) and the nozzle bracket (2) and the second short connecting rod (43).

5. The micro axisymmetric vector nozzle suitable for small aircraft according to claim 1, characterized in that: The hinge between the first short link (41), the long link (42), and the second short link (43) is achieved by a pin (45) in conjunction with a snap ring (46).

6. The micro axisymmetric vector nozzle for small aircraft according to claim 1, characterized in that: The axial deflection angle of the nozzle (1) is ±20°.

7. The micro axisymmetric vector nozzle for small aircraft according to claim 1, characterized in that: The sleeve (3) consists of a left half-ring sleeve (31) and a right half-ring sleeve (32), which are fixed to the engine body by high-temperature resistant bolts.

8. The micro axisymmetric vector nozzle for small aircraft according to claim 1, characterized in that: The gear (44) is fixed to the outer side of one end of the first short connecting rod (41) by welding. The central shaft hole of the gear (44) is connected to the hinge hole at that end of the first short connecting rod (41) and the two holes are of equal diameter.

9. The micro axisymmetric vector nozzle for small aircraft according to claim 1, characterized in that: The servo motor (5) is mounted on the side plate (33) via the mounting plate (35). The side plate (33) has a horizontal mounting groove in the middle. The mounting plate (35) is inserted and fixed in the horizontal mounting groove. The mounting plate (35) has a connecting hole. The servo motor (5) is fixed by fasteners passing through the connecting hole.

10. The micro axisymmetric vector nozzle for small aircraft according to claim 1, characterized in that: The servo motor (5) is an electric servo motor. The servo motor (5) is connected to the UAV control system and receives instructions from the UAV control system to operate. The rated torque of the servo motor (5) is greater than the torque required for the nozzle (1) to deflect to the maximum angle.

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