Lightweight variable sweep wing based on hot knife-twist spring and method thereof

Abstract

The application discloses a lightweight variable-trailing-sweep wing based on a hot knife-torsion spring and a method thereof. The variable-trailing-sweep wing comprises a wing, a torsion spring unfolding mechanism, an unfolding locking mechanism, a telescopic rod, a fuse rope, a hot knife mechanism and a connecting frame. Before unfolding, the unfolding locking mechanism is positioned and locked by the telescopic rod, the fuse rope and the connecting frame; the torsion spring in the torsion spring unfolding mechanism is twisted to store potential energy. During unfolding, the torsion spring is released, the wing is unfolded under the action of the torsion spring unfolding mechanism and is locked with the unfolding locking mechanism, and meanwhile, the tension spring in the torsion spring unfolding system stores energy. Meanwhile, the torsion spring is caused to fall off after the wing is unfolded, so that the torsion spring does not work during the trailing sweep. When trailing sweep is needed, the hot knife mechanism is powered to heat and then the fuse rope pressed on the heating pipe is broken, the unfolding locking mechanism and the wing are trailing swept under the action of the tension spring and aerodynamic force, and the telescopic rod is lengthened to the designed position to be locked, so that the wing is locked in the trailing sweep state. The application can be widely applied to variable-body aircrafts.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of variable aircraft, in particular to the technical field of lightweight variable rear-swept wing based on hot knife-torsion spring and method thereof. BACKGROUND

[0002] Variable sweep wing refers to the wing that can be driven by a mechanism to rotate around a rotation shaft along the direction of the fuselage. The variable sweep wing can improve the flight efficiency of the aircraft in a wide speed range, and can also take into account the high and low speed flight of the aircraft, so that the aircraft can maintain high flight capability at various flight speeds. Since the concept of variable rear-swept wing was proposed in Germany in the middle of the 20th century, the complex driving structure, large weight, complex operation and high maintenance cost of the variable rear-swept wing have always limited the development of the variable rear-swept wing aircraft.

[0003] In recent years, with the continuous emergence of new structures and new materials, a new path has been opened up for the development of lightweight variable rear-swept mechanism, so the driving mechanism of the variable rear-swept wing has become a research hotspot again. Simplifying the structure, reducing the size and weight of the structure, and reducing the maintenance cost are the main goals of the new round of research and development of the variable rear-swept wing mechanism. Therefore, it is necessary to design a variable sweep angle mechanism based on a lightweight driving device and a triggering device. SUMMARY

[0004] The purpose of the present application is to solve the problems in the prior art, and to propose a lightweight variable rear-swept wing based on hot knife-torsion spring and method thereof. The wing can be driven by a mechanism to rotate around a rotation shaft along the direction of the fuselage. The driving structure is ingenious and light, the operation is simple, the overall weight is light, and it can be widely used in variable aircraft.

[0005] To achieve the above-mentioned purpose, the present application proposes a lightweight variable rear-swept wing based on hot knife-torsion spring, which comprises a wing, a torsion spring unfolding mechanism, an unfolding locking mechanism, an extension rod, a fuse rope, a hot knife mechanism and a connecting frame.

[0006] One end of the wing is installed on the torsion spring unfolding mechanism and can rotate around the first rotation shaft of the torsion spring unfolding mechanism. The first rotation shaft of the torsion spring unfolding mechanism is installed on the connecting frame. The unfolding locking mechanism is installed on the upper part of the connecting frame. The unfolding locking mechanism is connected with the fuse rope in the middle part and the extension rod in the lower part. The other end of the extension rod is connected to the connecting frame.

[0007] The wing is provided with a locking rod for cooperation with the unfolding locking mechanism. One end of the wing is provided with a torsion spring working hole for connecting a torsion spring working rod, a wing rotation shaft hole for connecting the first rotation shaft, an unlocking rod for unlocking the torsion spring, and a tension spring working hole for connecting a tension spring.

[0008] The torsion spring unfolding mechanism is connected with the wings and the connecting frame, the torsion springs of the torsion spring unfolding mechanism are symmetrically arranged on both sides of the wings, the torsion spring fixing rods of the torsion springs are fixed by torsion spring fixing blocks and torsion spring stop blocks, the torsion spring fixing blocks are fixedly connected with the connecting frame by the first bolts;

[0009] The unfolding locking mechanism is internally provided with a pair of compression springs and a pair of locking tongues, and the compression springs and the locking tongues are determined to move along the movement tracks by the unfolding locking mechanism shell and the unfolding locking mechanism end cover, and the unfolding locking mechanism shell and the unfolding locking mechanism end cover are fixedly connected by the second bolts.

[0010] The telescopic rod is composed of an inner telescopic rod, a spring buckle and an outer telescopic rod, and the telescopic rod is connected with the unfolding locking mechanism and the connecting frame.

[0011] The both ends of the fuse rope are respectively connected with the symmetrically arranged unfolding locking mechanisms, and the fuse rope is pressed on the heating pipe of the hot knife mechanism; the hot knife mechanism is composed of a heating pipe, a wire and a hot knife seat.

[0012] As preferred, the middle part of the upper part of the wing is provided with a square groove, and the bottom of the square groove is provided with a T-shaped locking rod; the upper left end of the wing is provided with a left-extended triangular unlocking rod, the upper part of the wing right to the unlocking rod is longitudinally provided with a wing rotating shaft hole, the first rotating shaft is inserted into the wing rotating shaft hole, the upper part of the wing left to the wing rotating shaft hole is longitudinally provided with a tension spring working hole, one end of the tension spring is connected into the tension spring working hole, the other end of the tension spring is connected with the connecting frame, the upper part of the wing right to the wing rotating shaft hole is longitudinally provided with a torsion spring working hole, and the torsion spring working rod of the torsion spring is inserted into the torsion spring working hole.

[0013] As preferred, the both ends of the first rotating shaft are sleeved with the first bearings, and the first bearings are embedded into the connecting frame; the both sides of the torsion spring fixing block are vertically provided with T-shaped grooves, the torsion spring stop block is a U-shaped structure, and the both ends of the torsion spring stop block are matched into the T-shaped grooves of the torsion spring fixing block.

[0014] As preferred, the wing and the unfolding locking mechanism are matched to form a complete airfoil.

[0015] As preferred, the unfolding locking mechanism comprises an unfolding locking mechanism shell, unfolding locking mechanism end covers fixed on both ends of the unfolding locking mechanism shell by the second bolts, compression springs and locking tongues installed in the inner cavity of the unfolding locking mechanism shell, the unfolding locking mechanism shell is internally provided with a pair of compression springs and a pair of locking tongues symmetrically arranged in the up and down direction, one side of the compression spring is fixed on the unfolding locking mechanism end cover, the other side is abutted with one end surface of the locking tongue, the other end surface of the locking tongue is an inclined surface, the front middle part of the unfolding locking mechanism shell is provided with a square through hole, and the unfolding locking mechanism shell rear side upper part is provided with a square ring, the square ring is sleeved and fixed with the fuse rope, and the unfolding locking mechanism shell rear side lower part is symmetrically provided with a hole plate, and one end of the telescopic rod is connected with the hole plate.

[0016] As preferred, the telescopic rod is connected with the unfolding locking mechanism and the connecting frame through the screw nut, the second bearing and the second rotating shaft; the telescopic rod is designed as a hollow tube, and the telescopic rod comprises an inner telescopic rod and an outer telescopic rod locked by a spring buckle, and only the spring buckle with light weight and high rigidity is used for locking.

[0017] As preferred, the fuse rope is an organic material with low melting point, high strength, low creep and low density, and the fuse rope is a Dyneema rope prepared from ultra-high molecular weight polyethylene.

[0018] As preferred, the heating pipe is a ceramic heating pipe with light weight and fast heating.

[0019] As preferred, the hot knife mechanism comprises the heating pipe, the wire and the hot knife seat, the number of the heating pipes fixed on the hot knife seat is 2, the two heating pipes are perpendicular to each other, the number of the wires connected with one end of the heating pipe is 2, and the heating pipe is connected with the power supply through the wire.

[0020] A control method of the hot knife-torsion spring based lightweight variable sweep wing based on any one of the above, characterized in that:

[0021] When the torsion spring is installed, the torsion spring working rod is inserted into the torsion spring working hole of the wing, the torsion spring fixing rod is inserted into the T-shaped slot vertically arranged on both sides of the torsion spring fixing block, and the torsion spring fixing block cooperates with the torsion spring stop block; before the torsion spring fixing block is unfolded, the torsion spring fixing rod is tightly pressed on the torsion spring stop block, and the torsion spring stop block is fixed in the T-shaped slot by the friction force generated by the torsion spring fixing block, and no sliding occurs;

[0022] Before the wing is unfolded, the unfolding locking mechanism determines the position and is fixed by the telescopic rod, the fuse rope and the connecting frame;

[0023] When the wing is unfolded under the action of the potential energy of the torsion spring, the locking rod on the wing cooperates with the wing connecting groove of the unfolding locking mechanism, and is locked by the unfolding locking mechanism shell and the lock tongue; after the wing is locked with the unfolding locking mechanism, the wing is always fixed with the unfolding locking mechanism, and the wing is determined in position and fixed by the telescopic rod, the fuse rope and the connecting frame, and the unfolded state is maintained;

[0024] During the unfolding process of the wing, the potential energy of the torsion spring decreases, the pressure of the torsion spring fixing rod on the torsion spring stop block decreases, and at the same time, the unlocking rod collides with the torsion spring stop block, so that the torsion spring stop block falls off from the T-shaped slot vertically arranged on both sides of the torsion spring fixing block; at this time, the torsion spring fixing rod is not fixed, and the torsion spring does not do work in the subsequent change process;

[0025] The wing is in the unfolded state, the hot knife mechanism is powered to heat, the fuse cord pressed on the heating pipe is broken, at this time the wing is unlocked, then the wing is swept back under the action of the tension spring and the aerodynamic force until the telescopic rod is extended to the designed position and locked, and the wing determines the swept back state through the locked telescopic rod and keeps it.

[0026] The beneficial effects of the present application are:

[0027] The driving structure of the present application is ingenious, light and simple to operate, and has light overall weight, and can be widely applied to morphing aircraft: in the folded state, the torsional spring is released to rotate the wing, and the locking rod on the wing is connected with the unfolding locking mechanism after rotation to keep the unfolded state; in the unfolded state, the heating pipe in the hot knife mechanism is powered to heat, the temperature of the heating pipe is raised, and after a period of time, the fuse cord pressed on the heating pipe is melted, and the wing and the unfolding locking mechanism change to the swept back state under the action of the tension spring and the air load; in the swept back state, the length of the telescopic rod is locked to ensure the sweep back angle, and the wing and the unfolding locking mechanism keep the swept back state under the action of the telescopic rod.

[0028] The features and advantages of the present application will be described in detail in conjunction with the embodiments and the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 is the axial side view of the variable sweep wing based on the hot knife-torsional spring lightweight variable sweep wing and method thereof of the present application;

[0030] Figure 2 is the structural schematic view of the wing based on the hot knife-torsional spring lightweight variable sweep wing and method thereof of the present application;

[0031] Figure 3 is the part explosion view of the torsional spring unfolding mechanism based on the hot knife-torsional spring lightweight variable sweep wing and method thereof of the present application;

[0032] Figure 4 is the part explosion view of the unfolding locking mechanism based on the hot knife-torsional spring lightweight variable sweep wing and method thereof of the present application;

[0033] Figure 5 is the part explosion view of the telescopic rod based on the hot knife-torsional spring lightweight variable sweep wing and method thereof of the present application;

[0034] Figure 6 is the part explosion view of the hot knife mechanism based on the hot knife-torsional spring lightweight variable sweep wing and method thereof of the present application;

[0035] Figure 7 is the unlocking schematic view of the torsional spring after work based on the hot knife-torsional spring lightweight variable sweep wing and method thereof of the present application;

[0036] Figure 8is a schematic diagram of the unfolded state of the variable sweep wing of the lightweight variable sweep wing based on hot knife-torsion spring and its method of the present application;

[0037] Figure 9 is a schematic diagram of the swept state of the variable sweep wing of the lightweight variable sweep wing based on hot knife-torsion spring and its method of the present application;

[0038] Figure 10 is a schematic diagram of the torsion spring / hot knife scheme technical roadmap of the lightweight variable sweep wing based on hot knife-torsion spring and its method of the present application;

[0039] Figure 11 is a schematic diagram of the lock tongue force analysis of the lightweight variable sweep wing based on hot knife-torsion spring and its method of the present application;

[0040] Figure 12 is a schematic diagram of the telescopic rod support force analysis of the lightweight variable sweep wing based on hot knife-torsion spring and its method of the present application;

[0041] Figure 13 is a schematic diagram of the wing inertia tensor of the lightweight variable sweep wing based on hot knife-torsion spring and its method of the present application;

[0042] Figure 14 is a schematic diagram of the fuse rope temperature change of the lightweight variable sweep wing based on hot knife-torsion spring and its method of the present application;

[0043] Figure 15 is a schematic diagram of the unfolding angle and time change of the lightweight variable sweep wing based on hot knife-torsion spring and its method of the present application;

[0044] Figure 16 is a schematic diagram of the lock tongue centroid change of the lightweight variable sweep wing based on hot knife-torsion spring and its method of the present application;

[0045] Figure 17 is a schematic diagram of the swept simulation result of the hot knife mechanism of the lightweight variable sweep wing based on hot knife-torsion spring and its method of the present application.

[0046] Figure: wing 1, locking rod 1-1, torsion spring working hole 1-2, wing rotation shaft hole 1-3, unlocking rod 1-4, tension spring working hole 1-5, torsion spring unfolding mechanism 2, first rotation shaft 2-1, torsion spring 2-2, torsion spring working rod 2-2-1, torsion spring fixing rod 2-2-2, first bearing 2-3, torsion spring fixing block 2-4, tension spring 2-5, torsion spring stop block 2-6, first bolt 2-7, unfolding locking mechanism 3, unfolding locking mechanism shell 3-1, wing connecting groove 3-1-1, fuse rope connecting groove 3-1-2, telescopic rod connecting hole 3-1-3, unfolding locking mechanism end cover 3-2, second bolt 3-3, compression spring 3-4, lock tongue 3-5, telescopic rod 4, inner telescopic rod 4-1, spring buckle 4-2, outer telescopic rod 4-3, nut 4-4, second bearing 4-5, second rotation shaft 4-6, fuse rope 5, hot knife mechanism 6, heating pipe 6-1, wire 6-2, hot knife seat 6-3, connecting frame 7;

[0047] Figure 11 Wherein Fn is the lock tongue supporting force, Fy is the spanwise force, and Fz is the axial force. Figure 15 Wherein the highest point at 3.25s is the rope melting point. DETAILED DESCRIPTION

[0048] Reference Figures 1-17 The present application comprises a wing 1, a torsion spring unfolding mechanism 2, an unfolding locking mechanism 3, a telescopic rod 4, a fuse rope 5, a hot knife mechanism 6, and a connecting frame 7.

[0049] One end of the wing 1 is installed on the torsion spring unfolding mechanism 2 and can rotate around the first rotation shaft 2-1 of the torsion spring unfolding mechanism 2, the first rotation shaft 2-1 of the torsion spring unfolding mechanism 2 is installed on the connecting frame 7, the upper part of the connecting frame 7 is installed with the unfolding locking mechanism 3, the middle part of the unfolding locking mechanism 3 is connected with the fuse rope 5, and the lower part is connected with the telescopic rod 4, the other end of the telescopic rod 4 is connected to the connecting frame 7.

[0050] The wing 1 is provided with a locking rod 1-1 for cooperation with the unfolding locking mechanism 3, one end of the wing 1 is provided with a torsion spring working hole 1-2 for connecting the torsion spring working rod 2-2-1, a wing rotation shaft hole 1-3 for connecting the first rotation shaft 2-1, an unlocking rod 1-4 for unlocking the torsion spring, and a tension spring working hole 1-5 for connecting the tension spring 2-5.

[0051] The torsion spring unfolding mechanism 2 connects the wing 1 and the connecting frame 7, the torsion springs 2-2 of the torsion spring unfolding mechanism 2 are symmetrically arranged on both sides of the wing 1, the torsion spring fixing rods 2-2-2 of the torsion springs 2-2 are fixed by the torsion spring fixing blocks 2-4 and the torsion spring stop blocks 2-6, and the torsion spring fixing blocks 2-4 are fixedly connected with the connecting frame 7 through the first bolts 2-7.

[0052] The pair of compression springs 3-4 and the pair of locking tongues 3-5 are arranged inside the deployment locking mechanism 3, and the compression springs 3-4 and the locking tongues 3-5 are determined to have a movement track by the deployment locking mechanism shell 3-1 and the deployment locking mechanism end cover 3-2, and the deployment locking mechanism shell 3-1 and the deployment locking mechanism end cover 3-2 are fixedly connected by the second bolt 3-3;

[0053] The telescopic rod 4 is composed of an inner telescopic rod 4-1, a spring buckle 4-2 and an outer telescopic rod 4-3, and the telescopic rod 4 is connected with the deployment locking mechanism 3 and the connecting frame 7;

[0054] The fuse rope 5 is connected with the symmetrically arranged deployment locking mechanisms 3 at both ends, and the fuse rope 5 is pressed on the heating pipe 6-1 of the hot knife mechanism 6; the hot knife mechanism 6 is composed of the heating pipe 6-1, the wire 6-2 and the hot knife seat 6-3.

[0055] Based on the above-mentioned control method of the lightweight variable sweep wing based on the hot knife-torsional spring, the control method is characterized in that:

[0056] When the torsional spring 2-2 is installed, the torsional spring working rod 2-2-1 is inserted into the torsional spring working hole 1-2 of the wing 1, the torsional spring fixing rod 2-2-2 is inserted into the T-shaped slot vertically arranged on both sides of the torsional spring fixing block 2-4, and the torsional spring fixing block 2-2 cooperates with the torsional spring stop block 2-6; before the torsional spring fixing block 2-2 is unfolded, the torsional spring fixing rod 2-2-2 is tightly pressed on the torsional spring stop block 2-6, and the torsional spring fixing block 2-2 makes the torsional spring stop block 2-6 fixed in the T-shaped slot by the friction generated by the torsional spring fixing block 2-4, and the torsional spring stop block 2-6 does not slide;

[0057] Before the wing 1 is unfolded, the deployment locking mechanism 3 is determined to have a position and is fixed by the telescopic rod 4, the fuse rope 5 and the connecting frame 7;

[0058] When the wing 1 is unfolded under the action of the potential energy stored in the torsional spring 2-2, the locking rod 1-1 on the wing 1 cooperates with the wing connecting slot 3-1-1 of the deployment locking mechanism 3, and is locked by the deployment locking mechanism shell 3-1 and the locking tongue 3-5; after the wing 1 is locked with the deployment locking mechanism 3, the wing 1 and the deployment locking mechanism 3 are always fixedly connected, and the wing 1 is determined to have a position and is fixed by the telescopic rod 4, the fuse rope 5 and the connecting frame 7, and remains in the unfolded state;

[0059] During the unfolding process of the wing 1, the potential energy of the torsional spring 2-2 decreases, the pressure of the torsional spring fixing rod 2-2-2 on the torsional spring stop block 2-6 decreases, and at the same time, the unlocking rod 1-4 collides with the torsional spring stop block 2-6, so that the torsional spring stop block 2-6 falls off from the T-shaped slot vertically arranged on both sides of the torsional spring fixing block 2-4; at this time, the torsional spring fixing rod 2-2-2 is not fixed, and the torsional spring 2-2 does not do work in the subsequent change process;

[0060] When the wing 1 is in the deployed state, the hot knife mechanism 6 is energized and heated, causing the fuselage 5 pressing on the heating tube 6-1 to break. At this time, the wing 1 is unlocked. Then, the wing 1 sweeps back under the action of the tension spring 2-5 and aerodynamic force until the telescopic rod 4 extends to the designed position and locks. At the same time, the wing 1 determines the swept-back state through the locked telescopic rod 4 and maintains it.

[0061] Working process of this invention:

[0062] The present invention relates to a lightweight variable-sweep wing based on a hot blade-torsion spring and its method, which is described in conjunction with the accompanying drawings during operation.

[0063] like Figures 1 to 2 As shown, this invention provides a secondary locking variable-sweep wing based on a hot blade and torsion spring, which mainly includes a wing 1, a torsion spring deployment mechanism 2, a deployment locking mechanism 3, a telescopic rod 4, a fusible rope 5, a hot blade mechanism 6, and a connecting frame 7. The locking rod 1-1 in the wing 1 is used to engage with the wing connecting groove 3-1-1 of the deployment locking mechanism 3 and lock using the locking tongue 3-5 after the wing 1 is deployed. The torsion spring working hole 1-2 is used to fix the torsion spring working rod 2-2-2. The wing pivot hole 1-3 is used to connect the pivot 2-1 (illustrated in the figure). The unlocking rod 1-4 is used to knock down the torsion spring stop 2-6 after the wing 1 is deployed. The tension spring working hole 1-5 is used to connect the tension spring 2-5.

[0064] See Figure 3 As shown, the torsion spring deployment mechanism 2 used in this invention uses a torsion spring 2-2 as the power source for the deployment of the wing 1, so that the wing 1 rotates with the rotating shaft 2-1 and the first bearing 2-3. The torsion spring fixing rod 2-2-2 of the torsion spring 2-2 is inserted into the T-slot of the torsion spring fixing block 2-4, and the torsion spring stop block 2-6 cooperates with the torsion spring fixing block 2-4.

[0065] Mechanism composition and working principle

[0066] (1) Working principle:

[0067] In the retracted position, releasing the torsion spring causes the wing to rotate. After rotation, the locking lever on the wing connects to the deployment locking mechanism. The deployment locking mechanism is positioned by a mounting base, a telescopic rod, and a fusible rope, thus maintaining the deployed state.

[0068] The torsional spring does positive work when the wing changes from the folded state to the unfolded state, and if the torsional spring does not fail, it does negative work when the wing changes from the unfolded state to the rear-swept state. Therefore, the present scheme proposes a method for making the torsional spring fall off when the wing is unfolded, and the method is as follows: in the folded state, the torsional spring stores energy, the fixed torsional arm of the torsional spring exerts outward pressure F on the torsional spring block, and the torsional spring block is fixed at this time. When the wing is unfolded, the unlocking beam knocks off the torsional spring block, the fixed torsional arm of the torsional spring is no longer constrained by the working groove, and is in a free state, so that the torsional spring does not do negative work when the wing changes from the unfolded state to the rear-swept state.

[0069] When the wing is ready to be rear-swept in the unfolded state, the heating pipe in the hot knife mechanism is powered on, the temperature of the heating pipe is raised, and after a period of time, the fuse cord pressed tightly on the heating pipe is fused. The wing and the unfolding locking mechanism change to the rear-swept state under the action of the tension spring (energy storage when the wing is twisted) and air load.

[0070] In the rear-swept state, the length of the telescopic rod is locked, thereby ensuring the rear-swept angle, and the wing and the unfolding locking mechanism remain in the rear-swept state under the action of the telescopic rod, as shown in Figure 9 .

[0071] The technical route for designing and researching the wing unfolding and rear-swept mechanism based on the torsional spring / hot knife is shown in Figure 10 .

[0072] The key technologies of the method include:

[0073] 1. Design the wing unfolding and rear-swept mechanism according to the technical indicators, including the torsional spring unfolding mechanism for unfolding the wing, the unfolding locking mechanism for maintaining the unfolded state of the wing, the hot knife unlocking mechanism for triggering the wing to be rear-swept, and the rear-swept locking mechanism (telescopic rod) for maintaining the rear-swept state of the wing.

[0074] 2. Analyze the designed mechanism by mechanical modeling, and then analyze the dynamics of the wing unfolding and rear-swept process in adams to analyze the time required for the wing to unfold and be rear-swept.

[0075] (2) Mechanism composition:

[0076] Wing: The wing is provided with a rotating shaft connecting hole, a tension spring fixing hole, a torsional spring working rod fixing hole, an unlocking beam, and a locking rod. The unlocking column is used to knock off the torsional spring block when the wing is unfolded, and the locking column is used to connect the unfolding locking mechanism when the wing is unfolded.

[0077] Torsional spring: The torsional spring is used in the wing unfolding stage, the torsional spring wire diameter is 4 mm, the medium diameter is 24 mm, the number of turns is 9, the stiffness is 56 N·mm / deg, the free angle is 90°, the limit torque is 5000 N·mm, the torsional spring material is SWPB music steel wire, the spring single weight is 66 g, and a total of eight torsional springs are used, with a total mass of 528 g.

[0078] Tension spring: used to store energy when the wing is unfolded and provide a certain tension when the wing is changed to a backward sweep. The tension spring has a wire diameter of 1.6 mm, an outer diameter of 10 mm, a free length of 60 mm, a spring stiffness of 4.228 N / mm, a limit tension of 173 N, and a single mass of 12.3 g. A total of four are used, weighing 49.2 g.

[0079] Unfolding locking mechanism: the mechanism is shaped as shown in Figure 4 , used to connect the telescopic rod, the fuse rope, and the locking column on the wing. A pair of compression springs and locking tongues are provided inside the mechanism. The compression spring has an outer diameter of 3.76 mm, a free length of 7.95 mm, a compression height of 3.18 mm, a spring stiffness of 2.662 N / mm, a wire diameter of 0.46 mm, and a total number of turns of 6.72. The fully compressed load is 12.9 N.

[0080] Telescopic rod: the telescopic rod is designed by borrowing from the design of an umbrella handle, as shown in Figure 5 . It is composed of a large and small telescopic rod and a spring buckle, made of aluminum. The spring buckle is used to lock the telescopic rod in the swept-back state, and through holes are provided on both sides of the telescopic rod for mounting the rotating shaft.

[0081] Fuse rope: the fuse rope is made of organic material with low melting point, high strength, and low creep. Therefore, Dyneema rope made of ultra-high molecular weight polyethylene fiber (UHMWPE) is selected. The Dyneema rope has an elongation at break of 3.0-4.5% and a melting point of about 150°C. A 2 mm diameter Dyneema rope is used, and the 2 mm Dyneema rope has a maximum bearing tension of 2000 N.

[0082] Hot knife mechanism: the heating tube is an MCH ceramic heating tube with dimensions of φ3*57 mm and a weight of about 1.56 g. The lead wire is made of 0.5 mm nickel wire. The total weight of the heating tube and the hot knife support is 15 g.

[0083] 1. Component analysis and design

[0084] Unfolding locking mechanism: the working surface of the locking tongue in the unfolded state is subjected to the maximum pressure, as shown in Figure 11 . According to the aerodynamic load on the wing in the unfolded state, the force on the upper locking tongue is calculated to be 244.3 N and the force on the lower locking tongue is calculated to be 194.8 N by Adams software. Through Comsol simulation, it can be known that the maximum stress on the locking tongue under this force is about 65 MPa, which is less than the allowable stress of steel of 236 MPa when the safety factor is 1.5.

[0085] Compression spring: in order to make the lock tongue return to the original position in a short time to lock the wing, the natural frequency of the mass-spring coefficient formed by the lock tongue should be designed to be high, and the lock tongue can complete a motion cycle in a short time. The mass of the lock tongue is 4g and the compression spring stiffness is 2.662N / m, according to formula (1), the system frequency is calculated to be 26, so in the ideal state, the lock tongue takes 0.04s to return to the original position.

[0086] (1)

[0087] Telescopic rod design: in the swept-back state, the torque borne by the wing at the pivot due to aerodynamic force and spring tension is 506N·mm, and the vertical distance L between the wing pivot and the telescopic rod is 70mm, so the required support force F of the telescopic rod is 7.228N.

[0088] Torsion spring design: first, calculate the torque required for the wing to rotate 90° in 0.25s:

[0089] (2)

[0090] In formula (2), is the wing rotation angle, is the torque, is the wing inertia tensor.

[0091] According to the inertia tensor Izz obtained in Figure 13 and formula (2), it is calculated that when the constant torque T=6.987N·m, the wing can be deployed in 0.25s, and the torque of the torsion spring decays during the torsion process, so the maximum output torque of the required torsion spring is 10000N·mm obtained by simulation calculation in adams. When the torsion spring is actually used, it is symmetrically arranged on the left and right of the wing, so the working torsion angle of the designed torsion spring is 90°, and the maximum designed working torque is 5000N·mm, at this time the spring torsion stiffness is about 55N·mm / deg.

[0092] (3)

[0093] Taking the spring index C=6, according to formula (3), the curvature coefficient =1.15 is calculated.

[0094] (4)

[0095] The torsion spring material is SWP-B piano steel wire, and the spring wire diameter is estimated to be 4mm, so the material tensile strength =1810MPa is obtained, so ​= 905 MPa, the spring wire diameter d is calculated to be greater than or equal to 3.99 mm according to formula (4). Therefore, the spring wire diameter is taken as 4 mm.

[0096] (5)

[0097] (6)

[0098] (7)

[0099] Given that the elastic modulus E of the SWP-B piano wire is 200,000 MPa, the torsion spring diameter D is calculated to be 24 mm, and the axial moment of inertia of the spring wire circular section is 10.23 mm4according to formulas (5) to (7). The effective number of turns of the torsion spring is 8.5.

[0100] Fuse rope: The fuse rope uses a Dyneema rope with a diameter of 2 mm and a length of 200 mm, which is made of ultra-high molecular weight polyethylene fiber and has a tensile modulus of 100 GPa. In the retracted state, a pre-tightening force of 50 N is applied to the Dyneema rope. In the deployed state, the Dyneema rope is subjected to a tensile force of about 500 N due to the influence of the aerodynamic load. Under the action of the tensile force of 500 N, the Dyneema rope is calculated to be elongated by about 0.32 mm according to formula (8), and the influence of the tensile force is small.

[0101] (8)

[0102] Fuse time test: A voltage of 24 V is applied to the heating pipe to test the fuse time. The test device is that the fuse rope is wound in the middle of the heating pipe, and the thermocouple is placed between the fuse rope and the heating pipe and is pressed by the fuse rope. Figure 14 The temperature change of the fuse rope is shown. The heating pipe is powered at 0 s, and the rope is fused at 3.25 s. Then the thermocouple and the rope fall at the same time, and the temperature drops sharply. Therefore, the fuse rope needs about 3.25 s to fuse.

[0103] Power supply requirement: The power supply required by the heating pipe can output a voltage of 24 V and a current of 3.2 A.

[0104] 2. Deployment and retraction simulation analysis

[0105] Wing deployment simulation analysis: Under the action of the tension spring, the torsion spring and the compression spring, the deployment speed of the wing and the locking speed of the locking tongue in the deployment locking mechanism are analyzed, and an Adams model is established. The pre-tightening force of the torsion spring is set to 9900 N·mm, and the stiffness coefficient is 110 N·mm / deg; the stiffness coefficient of the tension spring is 4 N / mm.

[0106] The analysis results are shown in Figure 15 and 16 . Figure 15 ​The wing can be fully unfolded under the action of torsion spring and tension spring at 0.24s. Figure 16 The locking tongue can return to the original position under the action of compression spring at 0.253s, and the wing is locked.

[0107] Rear-sweep simulation analysis: Adams simulates the wing under the joint action of aerodynamic load and tension spring. The effect of telescopic rod is simulated by setting the damping coefficient of tension spring. The stiffness of tension spring is set to 4N / mm. In the unfolding simulation, it is tested that the tension spring is stretched to the maximum length and bears 120N. Therefore, in the rear-sweep simulation, the tension spring is set to have a preload of 120N. The simulation result is shown in Figure 17 The wing is swept back to 40° within 1s and can maintain the angle.

[0108] 3. Total weight

[0109] The mechanism calculates the mass components. The distance between the wing rotating shafts is 180mm, and the distance from the top of the unfolding and locking mechanism to the position where the tension spring is installed is 175mm. The total mass is shown in Table 1.

[0110] Table 1. Mass table of each component

[0111]

[0112] In addition, the mechanism occupies a space height of 165mm (from the hot knife mechanism connecting frame to the installation base).

[0113] The above examples are illustrative of the present application and are not limiting of the present application. Any simple transformation of the present application belongs to the protection scope of the present application.

Claims

1. A lightweight variable sweep wing based on hot knife-twist spring, characterized in that: It comprises a wing (1), a torsion spring unfolding mechanism (2), an unfolding locking mechanism (3), an extension rod (4), a fuse rope (5), a hot knife mechanism (6) and a connecting frame (7). One end of the wing (1) is installed on the torsion spring unfolding mechanism (2) and can rotate around the first rotating shaft (2-1) of the torsion spring unfolding mechanism (2), the first rotating shaft (2-1) of the torsion spring unfolding mechanism (2) is installed on the connecting frame (7), the upper part of the connecting frame (7) is installed with the unfolding locking mechanism (3), the middle part of the unfolding locking mechanism (3) is connected with the fuse rope (5), the lower part is connected with the extension rod (4), the other end of the extension rod (4) is connected to the connecting frame (7); The wing (1) is provided with a locking rod (1-1) for cooperating with the unfolding locking mechanism (3), one end of the wing (1) is provided with a torsion spring working hole (1-2) for connecting a torsion spring working rod (2-2-1), a wing rotating shaft hole (1-3) for connecting the first rotating shaft (2-1), an unlocking rod (1-4) for unlocking the torsion spring, and a tension spring working hole (1-5) for connecting a tension spring (2-5); The torsion spring unfolding mechanism (2) connects the wing (1) and the connecting frame (7), the torsion springs (2-2) of the torsion spring unfolding mechanism (2) are symmetrically arranged on both sides of the wing (1), the torsion spring fixing rods (2-2-2) of the torsion springs (2-2) are fixed by the torsion spring fixing blocks (2-4) and the torsion spring stop blocks (2-6), and the torsion spring fixing blocks (2-4) are fixedly connected with the connecting frame (7) through the first bolts (2-7); The unfolding locking mechanism (3) is internally provided with a pair of compression springs (3-4) and a pair of locking tongues (3-5), the compression springs (3-4) and the locking tongues (3-5) are determined to have a movement track through the unfolding locking mechanism shell (3-1) and the unfolding locking mechanism end cover (3-2), and the unfolding locking mechanism shell (3-1) and the unfolding locking mechanism end cover (3-2) are fixedly connected through the second bolts (3-3); The extension rod (4) is composed of an inner extension rod (4-1), a spring buckle (4-2) and an outer extension rod (4-3), and the extension rod (4) is connected with the unfolding locking mechanism (3) and the connecting frame (7); The fuse rope (5) is connected with the symmetrically arranged unfolding locking mechanisms (3) at both ends, and the fuse rope (5) is pressed on the heating pipe (6-1) of the hot knife mechanism (6); the hot knife mechanism (6) is composed of a heating pipe (6-1), a wire (6-2) and a hot knife seat (6-3).

2. The hot knife-torsion spring based light weight variable sweep wing according to claim 1, wherein: The upper middle part of the wing (1) is provided with a square groove, and the bottom of the square groove is provided with a T-shaped locking rod (1-1); the upper left end of the wing (1) is provided with a leftward extending triangular unlocking rod (1-4), the upper wing (1) is longitudinally provided with a wing rotating shaft hole (1-3) on the right side of the unlocking rod (1-4), the first rotating shaft (2-1) penetrates through the wing rotating shaft hole (1-3), the upper wing (1) is longitudinally provided with a tension spring working hole (1-5) below the left side of the wing rotating shaft hole (1-3), one end of the tension spring (2-5) is connected in the tension spring working hole (1-5), the other end of the tension spring (2-5) is connected with the connecting frame (7), the upper wing (1) is longitudinally provided with a torsion spring working hole (1-2) below the right side of the wing rotating shaft hole (1-3), and the torsion spring working rod (2-2-1) of the torsion spring (2-2) is inserted into the torsion spring working hole (1-2).

3. The hot knife-torsion spring based light weight variable sweep wing according to claim 1, wherein: The two ends of the first rotating shaft (2-1) are sleeved with first bearings (2-3), and the first bearings (2-3) are embedded in the connecting frame (7); the two sides of the torsion spring fixing block (2-4) are vertically provided with T-shaped grooves, the torsion spring stop block (2-6) is a U-shaped structure, and the two ends of the torsion spring stop block (2-6) are matched into the T-shaped grooves of the torsion spring fixing block (2-4).

4. The hot knife-torsion spring based light weight variable sweep wing of claim 1, wherein: The wing (1) and the unfolding locking mechanism (3) cooperate to form a complete airfoil.

5. The hot knife-torsion spring based light weight variable sweep wing of claim 1, wherein: The unfolding locking mechanism (3) comprises an unfolding locking mechanism shell (3-1), unfolding locking mechanism end covers (3-2) fixed at both ends of the unfolding locking mechanism shell (3-1) through second bolts (3-3), compression springs (3-4) and locking tongues (3-5) installed in the inner cavity of the unfolding locking mechanism shell (3-1), the unfolding locking mechanism shell (3-1) is internally provided with a pair of compression springs (3-4) and a pair of locking tongues (3-5) symmetrically arranged upward and downward, one side of the compression spring (3-4) is fixed on the unfolding locking mechanism end cover (3-2), the other side abuts against one end surface of the locking tongue (3-5), the other end surface of the locking tongue (3-5) is beveled, the front middle part of the unfolding locking mechanism shell (3-1) is provided with a square through hole, and the square through hole is provided with a square ring on the rear upper part of the unfolding locking mechanism shell (3-1), and the square ring is sleeved and fixed with a fuse rope (5); the rear lower part of the unfolding locking mechanism shell (3-1) is symmetrically provided with a hole plate, and one end of an extension rod (4) is connected to the hole plate.

6. The hot knife-torsion spring based light weight variable sweep wing as claimed in claim 1, wherein: The extension rod (4) is connected with the unfolding locking mechanism (3) and the connecting frame (7) through a nut (4-4), a second bearing (4-5) and a second rotating shaft (4-6); the extension rod (4) is designed as a hollow pipe, and the extension rod (4) comprises an inner extension rod (4-1) and an outer extension rod (4-3) locked by a spring buckle (4-2).

7. The hot knife-torsion spring based light weight variable sweep wing according to claim 1, wherein: The fuse rope (5) is an organic material with low melting point, high strength, low creep and low density, and the fuse rope (5) is a Dyneema rope prepared from ultra-high molecular weight polyethylene.

8. The hot knife-torsion spring based light weight variable sweep wing of claim 1, wherein: The heating pipe (6-1) is a ceramic heating pipe with light weight and fast heating.

9. The hot knife-torsion spring based light weight variable sweep wing according to claim 1, wherein: The hot knife mechanism (6) comprises a heating tube (6-1), a wire (6-2) and a hot knife seat (6-3), the hot knife seat (6-3) is fixed with two heating tubes (6-1), and the two heating tubes (6-1) are perpendicular to each other, one end of the heating tube (6-1) is connected with two wires (6-2), and the heating tube (6-1) is connected with an external power supply through the wire (6-2).

10. A control method for the lightweight variable-post-sweep wing based on the hot knife-torsion spring according to any one of claims 1-9, characterized in that: When the torsion spring (2-2) is installed, the torsion spring working rod (2-2-1) is inserted into the torsion spring working hole (1-2) of the wing (1), the torsion spring fixing rod (2-2-2) is inserted into the T-shaped slot vertically arranged on both sides of the torsion spring fixing block (2-4), and the torsion spring fixing block (2-2) cooperates with the torsion spring stop block (2-6); before the torsion spring (2-2) is unfolded, the torsion spring fixing rod (2-2-2) is tightly pressed on the torsion spring stop block (2-6), and the torsion spring (2-2) fixes the torsion spring stop block (2-6) in the T-shaped slot by the friction force generated with the torsion spring fixing block (2-4); Before the wing (1) is unfolded, the unfolding locking mechanism (3) determines the position and is fixed by the telescopic rod (4), the fuse rope (5) and the connecting frame (7); When the wing (1) is unfolded under the action of the potential energy stored by the torsion spring (2-2), the locking rod (1-1) on the wing (1) cooperates with the wing connecting slot (3-1-1) of the unfolding locking mechanism (3), and is locked by the unfolding locking mechanism shell (3-1) and the lock tongue (3-5); after the wing (1) is locked with the unfolding locking mechanism (3), the wing (1) is always fixed with the unfolding locking mechanism (3), and the wing (1) determines the position and is fixed by the telescopic rod (4), the fuse rope (5) and the connecting frame (7), maintaining the unfolded state; During the unfolding process of the wing (1), the potential energy of the torsion spring (2-2) decreases, the pressure of the torsion spring fixing rod (2-2-2) on the torsion spring stop block (2-6) decreases, and at the same time, the unlocking rod (1-4) collides with the torsion spring stop block (2-6), so that the torsion spring stop block (2-6) falls off from the T-shaped slot vertically arranged on both sides of the torsion spring fixing block (2-4); at this time, the torsion spring fixing rod (2-2-2) is not fixed, and the torsion spring (2-2) does not generate resistance force in the subsequent change process; In the unfolded state of the wing (1), the hot knife mechanism (6) is powered to heat, so that the fuse rope (5) pressed on the heating tube (6-1) is disconnected; at this time, the wing (1) is unlocked, and then the wing (1) is swept back under the action of the tension spring (2-5) and the aerodynamic force until the telescopic rod (4) is elongated to the designed position and is locked, and at the same time, the wing (1) determines the swept-back state by the locked telescopic rod (4) and always maintains the swept-back state.

Images