Aircraft variant nose cone structure based on flexible paper folding mechanism

Abstract

According to the aircraft variant nose cone structure based on the flexible paper folding mechanism, the nose cone structure comprises a plurality of multi-layer paper folding structure units with different sizes, and telescopic and bending deformation can be achieved; and by changing the size of the paper folding structure and increasing the number of layers of the paper folding structure units, the stretching and bending dimensions of the nose cone structure can be changed, so that different deformation requirements can be met. Each paper folding structure unit is formed by combining a trapezoid and a triangle, a plurality of layers of paper folding structure units form a tubular paper folding structure, and the tubular paper folding structures with different sizes are connected through the *-shaped transition unit and are overlapped up and down to form a foldable variant nose cone structure. The nose cone structure can be driven by external force to achieve stretching and bending deformation, and the structure can be kept unchanged in different deformation states after the external force is removed. The nose cone structure provided by the invention is a flexible deformable structure, has a paper surface deformation transition function in a bending process, and can realize large stretching and bending deformation. The nose cone is simple in structure and has the performance of large folding-unfolding ratio, large bending angle, high expansion and contraction rate and the like. When different materials and driving forms are adopted, the variable aircraft nose cone can meet the requirements of different deformation such as stretching and bending at the ascending section and the reentry section of the variable aircraft nose cone.

Description

Technical Field

[0001] The invention relates to an origami structure, in particular to an aircraft variant nose cone structure based on a flexible origami mechanism. Background Art

[0002] As a vehicle in the aerospace field, a morphing aircraft can change its appearance to adapt to different environmental requirements. At present, the research on morphing aircraft mainly focuses on the wings, and there is less research on the morphing nose cone. The morphing aircraft needs to extend the nose cone to reduce resistance during the ascent phase, bend the nose cone to change direction during the trajectory change phase, and shorten the nose cone to reduce aerodynamic heat load during the return phase.

[0003] Origami structures have the advantages of light weight, high structural strength and small space volume after folding. Their spatial expandability is widely used in the aerospace field. There are few studies on existing head cone origami structures, and most tubular origami structures can only achieve a certain degree of elongation and cannot achieve a steady-state configuration under different bending deformations. For special space application scenarios, there are specific requirements for origami structures, which require origami structures to achieve a certain degree of bending and maintain a stable configuration. Summary of the invention

[0004] In order to overcome the defects of the above-mentioned existing structures, the present invention provides a variant nose cone structure of an aircraft based on a flexible origami mechanism, which can achieve multiple deformations and maintain a stable configuration in different forms. The origami structure is simple, has a large deformation amount, occupies less internal space, has a large folding and unfolding ratio, a large bending angle, a high telescopic rate and other properties, and is expected to be applied to the nose cone part of a variant aircraft by using suitable materials and driving methods.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] The aircraft variant nose cone structure based on the flexible origami mechanism includes multiple multi-layer origami structural units of different sizes, which can realize extension and bending deformation. The extension and bending scale of the nose cone structure can be changed by changing the size of the origami structure and increasing the number of layers of the origami structural units, so as to adapt to different deformation requirements. The connection method of two adjacent tubular origami structures is as follows: the bottom surface and the top surface of different tubular origami structures are respectively connected by "M"-shaped transition units, and the connection is fixed with tape, that is, the tubular origami structures are arranged up and down. The nose cone origami mechanism is a flexible deformable structure, which can realize extension and bending deformation under the action of external force. After the external force is removed, the configuration can remain unchanged in the natural folding state, elongated state and bent state.

[0007] The origami structural unit is composed of two layers of isosceles trapezoids of two shapes (7, 8, 9 are of the same shape, and 10 is of a larger size) and isosceles triangles of the same shape (6, 11) distributed symmetrically in upper and lower mirror images. After the outer edge lines of the origami structural unit (10 and the sides of 6 and their mirror images) are connected, a layer of tubular origami structure can be formed by folding along the peak and valley creases. The tubular origami structure can be completely folded into a plane without considering the thickness. The completely folded pattern satisfies the polygon interior angle sum formula and the height (H) of the triangle is equal to that of the trapezoid, that is, the origami structural unit satisfies: the vertex angles of isosceles trapezoids 7, 8, 9, 10 are 150°, the base angles of isosceles triangles 6 and 11 are 30°, and the base lengths of isosceles triangles 6 and 11 are H, the side length of isosceles trapezoids 7, 8, and 9 is 2H, and the top length of isosceles trapezoids 7, 8, and 9 is the side length plus H. Tubular origami structures of different sizes are connected through a "M"-shaped transition unit. The median line of the "M"-shaped transition unit trapezoid is a valley fold, the diagonal line is a peak fold, and the top and bottom sides of the trapezoid are the same as the sides where origami structure units of different sizes meet. The top and bottom sides of 13, 14, 15, and 16 are connected to two tubular origami structures of different sizes and different numbers of unit layers.

[0008] The origami structural unit and the "M"-shaped transition unit are formed by folding the crease pattern along the crease line. The crease pattern of the top origami structure (1) is composed of multiple layers of origami structural units, and the crease patterns of the remaining origami structures (2, 3, 4, 5, 6) are composed of origami structural units and "M"-shaped transition units. The head cone structure formed by folding the origami structural unit and the "M"-shaped transition unit along the crease line can be stable in a naturally folded state; the head cone structure in the naturally folded state is subjected to an axial external force applied by the trapezoid at the top and bottom of the front side, and is bent and deformed, and can be stabilized in the bent state after the external force is removed; the top and bottom patterns of the head cone structure in the naturally folded state are stretched and deformed when subjected to an axial tensile force, and can maintain the same configuration in the stretched state after the external force is removed. The bending and expansion amount of the head cone structure is the superposition of multiple tubular origami structures of different sizes, and the tubular origami structures of different sizes have different bending degrees and expansion amounts after being subjected to force.

[0009] Changing the size of the origami structural unit and the "M"-shaped transition unit and the number of layers of the origami unit can change the telescopic and bending scale of the head cone origami mechanism, making the origami mechanism suitable for different scenarios. The tubular origami structure can achieve a large curvature and maintain its bending state when it contains three layers of origami units. Adding a silicone pneumatic actuator can drive the origami mechanism to deform, and the silicone pneumatic actuator is fixed by each layer of PET sheet. The silicone inflation deformation drives the PET sheet to move, causing the origami mechanism to deform. The final deformation effect of the origami mechanism is related to the driving performance of the silicone pneumatic actuator. The head cone structure is simple, has a large deformation amount, occupies less internal space, has a large folding and extension ratio, a large bending angle, a high telescopic rate and other properties, and is expected to be applied to the head cone part of the variant aircraft by using suitable materials and driving methods.

[0010] The force drive mode can be air drive or photoelectric drive using materials with shape memory function. The origami mechanism can use materials such as craft paper, silicone, plastic or thermoplastic polyurethane elastomer rubber to enhance its deformation ability.

[0011] Beneficial effects of the present invention:

[0012] Compared with the traditional origami mechanism, the aircraft variant nose cone structure based on the flexible origami mechanism of the present invention can achieve both bending steady state and axial elongation steady state, and has the function of paper surface deformation transition during bending. The origami mechanism is in the shape of a nose cone as a whole, can achieve flexible deformation, and has the advantages of large folding and extension ratio, large bending angle, high telescopic rate, etc. The nose cone structure can achieve bending and telescopic functions, and it is expected to be applied to the nose cone part of the variant aircraft by using suitable materials and driving methods, which can solve the problems of nose cone deformation and space accommodation. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0014] Figure 1 It is a crease diagram of a combination of an origami structure unit and a "M"-shaped transition unit of a variant nose cone structure of an aircraft based on a flexible origami mechanism according to an embodiment of the present invention, and a top view of the origami structure unit when it is completely folded;

[0015] Figure 2 is a front view of a naturally folded nose cone structure of an aircraft variant based on a flexible origami mechanism according to an embodiment of the present invention;

[0016] Figure 3 is a bending state diagram of a nose cone structure of an aircraft variant based on a flexible origami mechanism according to an embodiment of the present invention;

[0017] Figure 4is a top view of a nose cone structure of an aircraft variant based on a flexible origami mechanism according to an embodiment of the present invention;

[0018] Figure 5 is a diagram of a stretched state of a nose cone structure of an aircraft variant based on a flexible origami mechanism according to an embodiment of the present invention;

[0019] Figure 6 is a diagram of a natural folding state of a nose cone structure of an aircraft variant based on a flexible origami mechanism connected by PET thin plates according to an embodiment of the present invention;

[0020] Figure 7 is a front view of a naturally folded state of a nose cone structure of an aircraft variant based on a flexible origami mechanism connected by PET thin plates according to an embodiment of the present invention;

[0021] Figure 8 is a bending state diagram of a nose cone structure of an aircraft variant based on a flexible origami mechanism connected by PET thin plates according to an embodiment of the present invention;

[0022] Fig. 9 is an elongated state diagram of a nose cone structure of an aircraft variant based on a flexible origami mechanism connected by PET thin plates according to an embodiment of the present invention;

[0023] Fig.10 is an application diagram of a naturally folded state of a nose cone structure of an aircraft variant based on a flexible origami mechanism when connected to a frame according to an embodiment of the present invention;

[0024] Fig.11 is an application diagram of an aircraft variant nose cone structure based on a flexible origami mechanism in an extended state when connected to a frame according to an embodiment of the present invention;

[0025] Fig.12 This is an application diagram of a bent state of an aircraft variant nose cone structure based on a flexible origami mechanism when connected to a frame according to an embodiment of the present invention.

[0026] Fig.13 It is a front view of a naturally folded state of a nose cone structure of an aircraft variant based on a flexible origami mechanism when connected to a frame according to an embodiment of the present invention.

[0027] Figure Number

[0028] 1,2,3- tubular origami structure of two-layer origami structural unit, 4,5- tubular origami structure of three-layer origami structural unit, 7,8,9,10- isosceles trapezoid, 6,11- isosceles triangle, 13,14,15,16- water-elastic origami unit, 17- tubular origami structure of two-layer origami structural unit, 18- tubular origami structure of three-layer origami structural unit, 19,20,21,22- tubular origami structure of four-layer origami structural unit DETAILED DESCRIPTION

[0029] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0030] The following describes a variant nose cone structure of an aircraft based on a flexible origami mechanism according to a specific embodiment of the present invention with reference to the accompanying drawings.

[0031] like Figure 1-Figure 13 As shown, the aircraft variant nose cone structure based on the flexible origami mechanism according to the embodiment of the present invention comprises a tubular origami structure composed of multiple origami structural units of different sizes and multiple layers. The tubular origami structures of different sizes are connected by a "M"-shaped transition unit, which can achieve telescopic and bending deformation. Changing the size of the origami structural unit and the "M"-shaped transition unit and the number of layers of the origami unit can change the telescopic and bending scale of the nose cone structure. The origami structure is a flexible deformable structure that can achieve elongation and bending deformation under the action of external force, and can maintain the same configuration in the natural folded state, elongated state and bent state after the external force is removed.

[0032] like Figure 1 As shown, the crease diagram of the origami structural unit of the aircraft variant nose cone structure based on the flexible origami mechanism according to one embodiment of the present invention is composed of two layers of isosceles trapezoids of two shapes (7, 8, 9 are of the same shape, and 10 is of a larger size) and isosceles triangles of the same shape (6, 11) distributed symmetrically in upper and lower mirror images. The dotted lines in the crease diagram are valley creases, and the solid lines are peak creases. The "M"-shaped transition unit is composed of an isosceles trapezoid and its midline and diagonal line, wherein the midline is the valley crease, and the diagonal line is the peak crease. The top and bottom sides of the trapezoid are the same in size as the sides where origami structural units of different sizes meet. The origami structural unit can be completely folded into a plane without considering the thickness. The completely folded pattern satisfies the polygon interior angle formula and the height (H) of the triangle and the trapezoid is equal, that is, the origami structural unit satisfies: the vertex angle of isosceles trapezoids 7, 8, 9, and 10 is 150°, the base angle of isosceles triangles 6 and 11 is 30°, and the base length of isosceles triangles 6 and 11 is The length of the side of isosceles trapezoids 7, 8, and 9 is 2H, and the length of the top of isosceles trapezoids 7, 8, and 9 is the length of the side plus Origami structural units with different numbers of layers form a tubular origami structure, and the "M"-shaped transition unit connects two tubular origami structures with different sizes and different numbers of unit layers. The top and bottom edges of 13, 14, 15, and 16 connect two tubular origami structures with different sizes and different numbers of unit layers.

[0033] like Figure 2 As shown, a front view of a naturally folded nose cone structure of an aircraft variant based on a flexible origami mechanism according to an embodiment of the present invention is shown, wherein the origami mechanism is respectively composed of tubular origami structures 1, 2, 3 comprising two-layer origami structure units, and tubular origami structures 4, 5 comprising three-layer origami structure units. The size of the origami units of every two tubular origami structures from top to bottom differs by 20%. The connection method of two adjacent tubular origami structures is as follows: the bottom surface (1) of the tubular origami structure and the top surface (2) of the tubular origami structure are respectively connected through a "R"-shaped transition unit, and the connection is fixed by using a tape; the bottom surface (2) of the tubular origami structure and the top surface (3) of the tubular origami structure are respectively connected through a "R"-shaped transition unit, and the connection is fixed by using a tape; the bottom surface (3) of the tubular origami structure and the top surface (4) of the tubular origami structure are connected through a "R"-shaped transition unit, and the connection is fixed by using glue; the bottom surface (4) of the tubular origami structure and the top surface (5) of the tubular origami structure are connected through a "R"-shaped transition unit, and the connection is fixed by using glue; the bottom surface (5) of the tubular origami structure and the top surface (6) of the tubular origami structure are connected through a "R"-shaped transition unit, and the connection is fixed by using glue, that is, the tubular origami structures are arranged and distributed up and down. The nose cone structure can achieve expansion and contraction and bending deformation under the action of external force, and can maintain the configuration unchanged in the natural folded state, elongated state and bent state after the external force is removed.

[0034] like Figure 3 As shown, according to a bending state diagram of a variant nose cone structure of an aircraft based on a flexible origami mechanism according to an embodiment of the present invention, bending deformation can be achieved by applying an axially outward force to the front side of the nose cone structure. There is a paper surface deformation transition function during the bending process, and the nose cone structure changes from a vertical state to a bent state. After the force is removed, the bending state of the origami structure remains unchanged.

[0035] like Figure 4 As shown, according to an overhead view of a variant nose cone structure of an aircraft based on a flexible origami mechanism according to an embodiment of the present invention, an axial inward pressure is applied to the nose cone structure. Regardless of the thickness of the origami material, the origami mechanism can be completely folded into a plane, and the flexible planes are stacked in parallel in the folded state.

[0036] like Figure 5As shown, according to a stretching state diagram of a variant nose cone structure of an aircraft based on a flexible origami mechanism according to an embodiment of the present invention, an axial outward pulling force is applied to the nose cone structure, and the nose cone structure reaches an elongated state. After the force is removed, the elongated state of the nose cone structure remains unchanged, that is, it reaches the elongated state.

[0037] like Figure 6 As shown in 7, a natural folding state diagram of a variant nose cone structure of an aircraft based on a flexible origami mechanism connected by PET thin plates according to an embodiment of the present invention, the variant nose cone origami mechanism connected by PET thin plates is respectively composed of a tubular origami structure 17 including two layers of origami structural units, a tubular origami knot 18 including three layers of origami structural units, and tubular origami knots 19, 20, 21, and 22 including three layers of origami structural units. The size of the origami units of every two tubular origami structures differs by 20% from top to bottom.

[0038] like Figure 8 As shown, according to an embodiment of the present invention, a variant nose cone structure of an aircraft based on a flexible origami mechanism is connected by PET thin plates in a bending state, which can keep the configuration unchanged in the bending state.

[0039] like Fig. 9 As shown, according to an embodiment of the present invention, a variant nose cone structure of an aircraft based on a flexible origami mechanism is connected by PET sheets in an extended state, which can keep the configuration unchanged in the extended state.

[0040] like Fig.10 , 11 As shown in 12, according to an embodiment of the present invention, an aircraft variant nose cone structure based on a flexible origami mechanism is connected to the frame in a natural folded state and an extended and bent state. When different materials and drive forms are used, it can be applied to the aircraft ascent stage and reentry stage to meet different deformation requirements such as telescopic and bending of its nose cone.

[0041] like Fig.13 As shown, a front view of a naturally folded state of a nose cone structure of an aircraft variant based on a flexible origami mechanism when connected to a frame according to an embodiment of the present invention.

[0042] Working principle of the present invention

[0043] The aircraft variant nose cone structure based on the flexible origami mechanism includes a plurality of origami structural units of different sizes and a "M"-shaped transition unit, which can realize extension and bending deformation. Changing the size of the origami structural unit and the "M"-shaped transition unit and the number of layers of the origami unit can change the extension and bending scale of the nose cone origami mechanism. The connection method of two adjacent tubular origami structures of different sizes is as follows: the bottom surface and the top surface of different tubular origami structures are respectively connected by the "M"-shaped transition unit, and the connection is fixed with tape; or the bottom surface and the top surface of different tubular origami structures connected by PET thin plates are respectively glued to the two sides of the PET transparent thin plate by glue, that is, the tubular origami structures are arranged up and down. The nose cone origami structure is a flexible deformable structure, which can realize extension and bending deformation under the action of external force. After the external force is removed, the configuration can be kept unchanged in the natural folding state, elongated state and bent state.

[0044] The aircraft variant nose cone structure based on the flexible origami mechanism, the origami structural unit is composed of two layers of isosceles trapezoids of two shapes (7, 8, 9 are of the same shape, 10 is of a larger size) and isosceles triangles of the same shape (6, 11) distributed symmetrically in the upper and lower mirror images. After the outer edge lines of the origami structural unit (10 and the side edges of 6 and their mirror images) are connected, a layer of tubular origami structure can be formed by folding along the peak-valley creases. The "M"-shaped transition unit is composed of an isosceles trapezoid and its midline and diagonal line, wherein the midline is the valley crease, and the diagonal line is the peak crease. The top and bottom sides of the trapezoid are the same in size as the sides where origami structural units of different sizes meet. The origami structural unit can be completely folded into a plane without considering the thickness. The completely folded pattern satisfies the polygon interior angle formula and the height (H) of the triangle and the trapezoid is equal, that is, the origami structural unit satisfies: the vertex angle of isosceles trapezoids 7, 8, 9, and 10 is 150°, the base angle of isosceles triangles 6 and 11 is 30°, and the base length of isosceles triangles 6 and 11 is H, the side length of isosceles trapezoids 7, 8, and 9 is 2H, and the top length of isosceles trapezoids 7, 8, and 9 is the side length plus H. Origami structural units with different numbers of layers form a tubular origami structure, and the "M"-shaped transition unit connects two tubular origami structures with different sizes and different numbers of unit layers. The top and bottom edges of 13, 14, 15, and 16 are connected to two tubular origami structures with different sizes and different numbers of unit layers.

[0045] The origami structural unit and the "M"-shaped transition unit are folded by the crease pattern according to the crease line. The tubular origami structure formed by the multi-layer origami structural unit can be stabilized in a naturally folded state; the tubular origami structure in the naturally folded state is subjected to an axial external force applied by the trapezoid at the top and bottom of the front side, and is bent and deformed, and can be stabilized in a bent state after the external force is removed; the top and bottom patterns of the tubular origami structure in the naturally folded state are stretched and deformed when subjected to an axial tensile force, and can maintain the configuration unchanged in the stretched state after the external force is removed. In addition, the tubular origami structure can be completely folded into a plane when subjected to a certain axial pressure without considering the thickness of the material. Correspondingly, the bending and expansion amount of the head cone origami mechanism is the superposition of multiple tubular origami structures of different sizes, and the bending and expansion degrees and expansion amounts of tubular origami structures of different sizes are different after being subjected to force. The head cone structure can maintain a naturally folded state, and can maintain a bent state and an elongated state after being deformed by forces in different directions in the naturally folded state. In addition, the nose cone structure can be completely folded into a plane when subjected to a certain axial pressure without considering the thickness of the material. The nose cone structure is simple, has a large deformation amount, occupies less internal space, has a large folding and unfolding ratio, a large bending angle, and a high telescopic rate. It is expected to be applied to the nose cone part of a variant aircraft by using appropriate materials and driving methods.

[0046] The force drive mode can be air drive or photoelectric drive using materials with shape memory function. The origami mechanism can use materials such as craft paper, silicone, plastic or thermoplastic polyurethane elastomer rubber to enhance its deformation ability.

[0047] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, in this specification, those skilled in the art may combine different embodiments or examples described and features of different embodiments or examples without conflicting with each other.

[0048] Although several embodiments of the present invention are shown and described above, it can be understood that the above embodiments are exemplary and cannot be construed as limitations of the present invention. A person skilled in the art can change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A variant nose cone structure of an aircraft based on a flexible origami mechanism, characterized in that: It contains multiple tubular origami structures of different sizes. The tubular origami structure is composed of multi-layer origami structural units. The multi-layer origami structural units of different sizes are connected through a "M"-shaped transition. Changing the number of origami structural unit layers can change the expansion and contraction and bending scales of the tubular origami structure, and thus change the expansion and contraction and bending scales of the head cone structure. The head cone structure comprises a plurality of tubular origami structures (1, 2, 3, 4, 5, 6), wherein two adjacent tubular origami structures are connected in the following manner: the bottom surface (1) of the tubular origami structure is connected to the top surface (2) of the tubular origami structure through a "R"-shaped transition unit, and the connection is fixed by adhesive tape; the bottom surface (2) of the tubular origami structure is connected to the top surface (3) of the tubular origami structure through a "R"-shaped transition unit, and the connection is fixed by adhesive tape; the bottom surface (3) of the tubular origami structure is connected to the top surface (4) of the tubular origami structure through a "R"-shaped transition unit, and the connection is fixed by glue; the bottom surface (4) of the tubular origami structure is connected to the top surface (5) of the tubular origami structure through a "R"-shaped transition unit, and the connection is fixed by glue; the bottom surface (5) of the tubular origami structure is connected to the top surface (6) of the tubular origami structure through a "R"-shaped transition unit, and the connection is fixed by glue, that is, the tubular origami structures are arranged and distributed in order from small to large in size.

2. The aircraft variant nose cone structure based on the flexible origami mechanism according to claim 1, characterized in that: The origami structural unit and the "M"-shaped transition unit are formed by folding the crease pattern according to the crease line. The crease pattern of the top layer origami structure (1) is composed of multiple layers of origami structural units, and the crease patterns of the remaining origami structures (2, 3, 4, 5, 6) are composed of origami structural units and "M"-shaped transition units. The head cone structure can be stabilized in a naturally folded state; when the head cone structure in the naturally folded state is subjected to an axial external force applied by the trapezoid at the top and bottom of the front side, it is bent and deformed, and can be stabilized in the bent state after the external force is removed; when the top and bottom layers of the head cone structure in the naturally folded state are subjected to an axial tensile force, they are stretched and deformed, and can maintain the configuration unchanged in the stretched state after the external force is removed.

3. The aircraft variant nose cone structure based on the flexible origami mechanism according to claim 1, characterized in that: The bending degree and expansion amount of the head cone structure are the superposition of multiple tubular origami structures of different sizes, and the tubular origami structures of different sizes bend and expand at different degrees and expansion amounts after being subjected to force. The head cone structure can maintain a natural folding state, and can maintain a bending state and an elongated state after being deformed by forces in different directions in the natural folding state.

4. The aircraft variant nose cone structure based on the flexible origami mechanism according to claim 1, characterized in that: The tubular origami structure formed by folding the origami structural unit is a flexible deformable structure. The tubular origami structure of the six-layer origami structural unit can achieve a bending angle of 90° and keep the bending configuration unchanged. During the bending process, it has a paper surface deformation transition function from a small trapezoidal expansion at the front side to a large trapezoidal folding at the rear side.

5. The tubular origami structure according to claim 1, characterized in that: The origami structural unit is composed of two layers of isosceles trapezoids of two shapes (7, 8, 9 are of the same shape, and 10 is of a larger size) and isosceles triangles of the same shape (6, 11) distributed symmetrically in the upper and lower mirror images. The "M"-shaped transition unit is composed of the trapezoid and its diagonal and median lines. After the outer edges of the origami structural unit (10 and the sides of 6 and its mirror image) are connected, a layer of tubular origami structure can be formed by folding along the peak and valley creases. The tubular origami structure can be completely folded into a plane without considering the thickness. The completely folded pattern satisfies the polygon interior angle sum formula and the height (H) of the triangle is equal to that of the trapezoid, that is, the origami structural unit satisfies: the vertex angles of isosceles trapezoids 7, 8, 9, 10 are 150°, the base angles of isosceles triangles 6 and 11 are 30°, and the base lengths of isosceles triangles 6 and 11 are The length of the side of isosceles trapezoids 7, 8, and 9 is 2H, and the length of the top of isosceles trapezoids 7, 8, and 9 is the length of the side plus Tubular origami structures of different sizes are connected through a "M"-shaped transition unit. The median line of the "M"-shaped transition unit trapezoid is a valley fold, the diagonal line is a peak fold, and the sizes of the top and bottom sides of the trapezoid are the same as the sides at the junction of origami structure units of different sizes.

6. The aircraft variant nose cone structure based on the flexible origami mechanism according to claim 1, characterized in that: The tubular origami structure of the head cone origami structure can be transitionally connected through a "M"-shaped transition unit, and can also be transitionally connected through a PET thin plate.

7. The aircraft variant nose cone structure based on the flexible origami mechanism according to claim 1, characterized in that: Adding a silicone pneumatic actuator inside can drive the origami mechanism to deform. The silicone pneumatic actuator is fixed through each layer of PET sheets. The silicone inflation deformation drives the PET sheets to move, causing the origami mechanism to deform. The final deformation effect of the origami mechanism is related to the driving performance of the silicone pneumatic actuator.

8. The aircraft variant nose cone structure based on the flexible origami mechanism according to claim 2, characterized in that: The force driving method can be gas driving or photoelectric driving using materials with shape memory function.

9. The aircraft variant nose cone structure based on the flexible origami mechanism according to claim 1, characterized in that: The material of the origami structure is craft paper, plastic or thermoplastic polyurethane elastomer rubber.

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