A single degree of freedom foldable parabolic structure with large folding ratio

Abstract

The application provides a single-degree-of-freedom foldable parabolic structure with a large foldable ratio, which comprises three identical foldable subunits and auxiliary plates connecting the subunits. The subunits comprise A, B and C, the auxiliary plates connecting the subunits comprise AB1 and AB2 between the subunits AB, and BC1 and BC2 between the subunits BC. Each subunit is composed of fourteen folding units. The application gives two schemes of a non-smooth and a smooth parabolic working surface according to the needs of different application scenarios. The mechanism with the non-smooth parabolic working surface has a smaller prismatic volume after folding because the plate surface is relatively flat, and the smooth surface can be used in application scenarios with high requirements for the accuracy of the parabolic working surface. Both of them have the single-degree-of-freedom characteristic, and can keep stable in the folded state, the folding state and the unfolded state. In another aspect of the application, it is simple to manufacture and install, and convenient to use and transport.

Description

Technical Field

[0001] This invention relates to the field of parabolic developable structure technology, and in particular to a single-degree-of-freedom developable parabolic structure with a large unfolding ratio. Background Technology

[0002] Parabolic deployable structures have broad application prospects in aerospace, construction and other fields due to their advantages of large folding-to-spread ratio and ability to achieve large-scale deployment and small-volume loading. In recent years, they have received widespread attention from domestic scholars.

[0003] Chinese patent document CN114865276B discloses a space-deployable parabolic antenna back frame based on a thick plate origami structure. This invention has a simple structure, a large folding ratio, and is convenient for production and assembly, making it suitable for mass production. However, after fully unfolding, the working surface is rugged, requiring the addition of additional reflective material to function as an antenna, making its use more complex. Furthermore, the working surface is a parabolic cylinder, resulting in lower efficiency compared to a parabolic sphere. Chinese patent document CN219513350U discloses a deployable parabolic antenna. The fully unfolded working surface of this invention can form a parabolic sphere, composed of four panels fixed together by a locking bolt. Each panel must be manually slid individually during use, arranging and positioning them sequentially to achieve the parabolic shape. Each panel also requires individual unfolding via ribs. While this makes the mechanism lightweight for transport, the unfolding process is cumbersome when using the antenna. Chinese patent document CN112151930B discloses a parabolic structure with a large folding-to-open ratio. This mechanism uses rigid folding and opening, has high folding and opening stability, and possesses a single degree of freedom and a high folding-to-open ratio. However, the design of this mechanism did not consider the instability of the hinge connection caused by the limited connecting surface at the fold. Summary of the Invention

[0004] In view of this, the purpose of this invention is to provide a single-degree-of-freedom parabolic structure with a large folding-to-unfold ratio. Considering the needs of different application scenarios, two schemes are provided: one with a non-smooth parabolic working surface and one with a smooth surface. The non-smooth parabolic working surface structure has a smaller prism-like volume after folding because the plate surface is relatively flat, while the smooth surface can be used in application scenarios with high requirements for the accuracy of the working surface shape. Both have single-degree-of-freedom characteristics and can remain stable in the folded, unfolded, and extended states. In another aspect, this invention is simple to manufacture and install, and convenient to use and transport.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a single-degree-of-freedom parabolic structure with a large folding-to-unfold ratio, comprising three identical foldable sub-units and auxiliary plates connecting the sub-units; the sub-units include a first sub-unit A, a second sub-unit B, and a third sub-unit C; the auxiliary plates connecting the sub-units include auxiliary plates AB1 and AB2 between the first sub-unit A and the second sub-unit B, and auxiliary plates BC1 and BC2 between the second sub-unit B and the third sub-unit C; each sub-unit is composed of fourteen folding units; the first sub-unit A includes folding units A1, A2, A3, A4, A5, A6, A7, and A8. Folding units A9, A10, A11, A12, AC, and AD are used, where folding units A1, A2, and A3 are identical to folding units A7, A8, and A9, respectively; folding units A4, A5, and A6 are identical to folding units A10, A11, and A12, respectively; folding units A1, A2, and A3 are mirror-symmetrical to folding units A4, A5, and A6, respectively; and folding units A4, A5, and A6 are mirror-symmetrical to folding units A7, A8, and A9, respectively. Symmetrical, folding units A7, A8, and A9 are mirror-symmetrical with folding units A10, A11, and A12, respectively. Auxiliary plates AC and AD are added between the rotating joints connecting folding units A6 and A9. The second subunit B includes folding units B1, B2, B3, B4, B5, B6, B7, B8, B9, B10, B11, B12, BC, and BD, where folding units B1, B2, and B3 are mirror-symmetrical with folding units B7, B8, and A12, respectively. Unit B9 is completely identical. Folding units B4, B5, and B6 are completely identical to folding units B10, B11, and B12, respectively. Folding units B1, B2, and B3 are mirror symmetrical to folding units B4, B5, and B6, respectively. Folding units B4, B5, and B6 are mirror symmetrical to folding units B7, B8, and B9, respectively. Folding units B7, B8, and B9 are mirror symmetrical to folding units B10, B11, and B12, respectively. Auxiliary plates BC and BD are added between the rotating joints connecting folding units B6 and B9.The third subunit C contains folding units C1, C2, C3, C4, C5, C6, C7, C8, C9, C10, C11, C12, CC, and CD. Folding units C1, C2, and C3 are identical to folding units C7, C8, and C9, respectively. Folding units C4, C5, and C6 are identical to folding units C10, C11, and C12, respectively. Folding units C1, C2, and C3 are mirror symmetrical to folding units C4, C5, and C6, respectively. Folding unit C6 is mirror-symmetric to folding units C7, C8, and C9, respectively. Folding units C7, C8, and C9 are mirror-symmetric to folding units C10, C11, and C12, respectively. Auxiliary plates CC and CD are added between the rotating joints connecting folding units C6 and C9. Auxiliary plates AB1 and AB2 connect folding units A3 and B12, and auxiliary plates BC1 and BC2 connect folding units B3 and C12. The concave surface of the deployable mechanism is called the front, and the convex surface is called the back. The crease vertices of the front and back creases of all plates are located on the same parabolic surface. Except for the auxiliary plates, the stretching direction of all folding units is parallel to the central axis of the parabolic surface.

[0006] In the first sub-unit A, the basic shape of the folding unit A1 is a triangle with a first twist angle, which is generally less than 90°. The three sides of the same face of the triangle are located on the same plane. The three sides of the front of the folding unit A1 are the first side of the front of the folding unit A1, the second side of the front of the folding unit A1, and the third side of the front of the folding unit A1. The three sides of the back of the folding unit A1 are the first side of the back of the folding unit A1, the second side of the back of the folding unit A1, and the third side of the back of the folding unit A1.

[0007] The basic shape of the folding unit A2 is a quadrilateral. Adjacent to the first twist angle of the folding unit A1 is the second twist angle, which is greater than 90° and less than 180°. The quadrilateral also has a third twist angle, greater than 90° and less than 180°. The four sides of the quadrilateral on the same face are not on the same plane. The four sides of the front of the folding unit A2 are the first side, second side, third side, and fourth side of the front of the folding unit A2. The four sides of the back of the folding unit A2 are the first side, second side, third side, and fourth side of the back of the folding unit A2. The third side of the front of the folding unit A2 is adjacent to the first side of the front of the folding unit A1 and is connected to it through the first rotating joint of the first subunit A. The folding unit A2 can rotate inward or outward along the axis of the first rotating joint of the first subunit A until it contacts one of the faces of the folding unit A1.

[0008] The basic shape of the folding unit A3 is a triangle, and the interior angle adjacent to the third twist angle of the folding unit A2 is the fourth twist angle, which is less than 90°. The three sides of the same face of the triangle are located on the same plane. The three sides of the front of the folding unit A3 are the first side, the second side, and the third side of the front of the folding unit A3. The three sides of the back of the folding unit A3 are the first side, the second side, and the third side of the back of the folding unit A3. The third side of the front of the folding unit A3 is adjacent to the first side of the front of the folding unit A2 and is connected to each other through the second revolute joint of the first subunit A. The folding unit A3 can rotate inward or outward along the axis of the second revolute joint of the first subunit A until it contacts a certain face of the folding unit A2.

[0009] The folding unit A4 is mirror-symmetrical to the folding unit A1. The three sides of the front of the folding unit A4 are the first side, the second side, and the third side of the front of the folding unit A4, and the three sides of the back of the folding unit A4 are the first side, the second side, and the third side of the back of the folding unit A4. The second side of the back of the folding unit A4 is adjacent to the second side of the back of the folding unit A1 and is connected to each other through the third rotating joint of the first subunit A. The folding unit A4 can rotate inward or outward along the axis of the third rotating joint of the first subunit A until it contacts a certain side of the folding unit A1.

[0010] The folding unit A5 is mirror-symmetrical to the folding unit A2. The four sides of the front of the folding unit A5 are the first side, the second side, the third side, and the fourth side of the front of the folding unit A5, respectively. The four sides of the back of the folding unit A5 are the first side, the second side, the third side, and the fourth side of the back of the folding unit A5, respectively. The third side of the front of the folding unit A5 is adjacent to the first side of the front of the folding unit A4 and is connected to each other through the fourth rotating joint of the first subunit A. The folding unit A5 can rotate inward or outward along the axis of the fourth rotating joint of the first subunit A until it contacts a certain side of the folding unit A4.

[0011] The folding unit A6 is mirror-symmetrical to the folding unit A3; the three sides of the front of the folding unit A6 are the first side, the second side, and the third side of the front of the folding unit A6, and the three sides of the back of the folding unit A6 are the first side, the second side, and the third side of the back of the folding unit A6; the third side of the front of the folding unit A6 is adjacent to the first side of the front of the folding unit A5 and is connected to each other through the fifth rotating joint of the first subunit A; the folding unit A6 can move inward or outward along the axis of the fifth rotating joint of the first subunit A. The folding unit A6 rotates outward until it contacts one of the faces of the folding unit A5. The second side of the reverse face of the folding unit A6 is adjacent to the second side of the reverse face of the folding unit A3 and is connected to each other through the sixth revolute joint of the first subunit A. The folding unit A6 can rotate inward or outward along the axis of the sixth revolute joint of the first subunit A until it contacts one of the faces of the folding unit A3. The first revolute joint, the second revolute joint, the third revolute joint, the fourth revolute joint, the fifth revolute joint, and the sixth revolute joint of the first subunit A together constitute a spatially symmetrical six-bar linkage.

[0012] The folding unit A7 is exactly the same as the folding unit A1; the positions of its sides are the same as those of the folding unit A1.

[0013] The folding unit A8 is identical to the folding unit A2; the positions of its sides are consistent with those of the folding unit A2; the third side of the front of the folding unit A8 is adjacent to the first side of the front of the folding unit A7 and is connected to each other through the seventh revolute joint of the first subunit A; the folding unit A8 can rotate inward or outward along the axis of the seventh revolute joint of the first subunit A until it contacts a certain side of the folding unit A7; the fourth side of the reverse side of the folding unit A8 is adjacent to the fourth side of the reverse side of the folding unit A5 and is connected to each other through the eighth revolute joint of the first subunit A; the folding unit A8 can rotate inward or outward along the axis of the eighth revolute joint of the first subunit A until it contacts a certain side of the folding unit A5.

[0014] The folding unit A9 is exactly the same as the folding unit A3; the positions of its sides are the same as those of the folding unit A3; the third side of the front of the folding unit A9 and the first side of the front of the folding unit A8 are adjacent and connected to each other through the ninth rotating joint of the first subunit A; the folding unit A9 can rotate inward or outward along the axis of the ninth rotating joint of the first subunit A until it contacts a certain side of the folding unit A8.

[0015] The basic shape of the auxiliary plate AC is an equilateral right-angled triangular prism. The three sides of the auxiliary plate AC are the first side, the second side, and the third side. The third side of the auxiliary plate AC is adjacent to the first side of the reverse side of the folding unit A6 and is connected to each other through the tenth rotation joint of the first subunit A. The auxiliary plate AC can rotate inward or outward along the axis of the tenth rotation joint of the first subunit A until it contacts a certain side of the folding unit A6.

[0016] The auxiliary plate AD and auxiliary plate AC are identical, as are the auxiliary plates AB1, AB2, BC1, and BC2 described below. The first side of auxiliary plate AD is adjacent to the first side of auxiliary plate AC and is connected to each other through the eleventh revolute joint of the first subunit A. Auxiliary plate AD can rotate inward or outward along the axis of the eleventh revolute joint of the first subunit A until it contacts a certain surface of auxiliary plate AC. The third side of auxiliary plate AD is adjacent to the first side of the reverse side of folding unit A9 and is connected to each other through the twelfth revolute joint of the first subunit A. Auxiliary plate AD can rotate inward or outward along the axis of the twelfth revolute joint of the first subunit A until it contacts a certain surface of folding unit A9. The fifth revolute joint, eighth revolute joint, ninth revolute joint, tenth revolute joint, eleventh revolute joint, and twelfth revolute joint of the first subunit A together constitute a spatially symmetrical six-bar linkage.

[0017] The folding unit A10 is exactly the same as the folding unit A4; the positions of each side of the folding unit A10 are the same as those of the folding unit A4; the second side of the reverse side of the folding unit A10 and the second side of the reverse side of the folding unit A7 are adjacent and connected to each other through the thirteenth rotating joint of the first subunit A; the folding unit A10 can rotate inward or outward along the axis of the thirteenth rotating joint of the first subunit A until it contacts a certain side of the folding unit A7.

[0018] The folding unit A11 is exactly the same as the folding unit A5; the positions of each side of the folding unit A11 are consistent with the positions of the folding unit A5; the third side of the front of the folding unit A11 and the first side of the front of the folding unit A10 are adjacent and connected to each other through the fourteenth rotating joint of the first subunit A; the folding unit A11 can rotate inward or outward along the axis of the fourteenth rotating joint of the first subunit A until it contacts a certain side of the folding unit A10.

[0019] The folding unit A12 is identical to the folding unit A6; the positions of its sides are consistent with those of the folding unit A6; the third side of the front of the folding unit A12 is adjacent to the first side of the front of the folding unit A11 and is connected to each other through the fifteenth revolute joint of the first subunit A; the folding unit A12 can rotate inward or outward along the axis of the fifteenth revolute joint of the first subunit A until it contacts a certain side of the folding unit A11; the second side of the reverse side of the folding unit A12 is adjacent to the second side of the reverse side of the folding unit A9 and is connected to each other through the sixteenth revolute joint of the first subunit A; the folding unit A12 can rotate inward or outward along the axis of the sixteenth revolute joint of the first subunit A until it contacts a certain side of the folding unit A9; the seventh side of the first subunit A... The revolute joints, the ninth revolute joint of the first subunit A, the thirteenth revolute joint of the first subunit A, the fourteenth revolute joint of the first subunit A, the fifteenth revolute joint of the first subunit A, and the sixteenth revolute joint of the first subunit A together constitute a spatially symmetrical six-bar linkage, which is the same as the spatially symmetrical six-bar linkage constituted by the first revolute joint of the first subunit A, the second revolute joint of the first subunit A, the third revolute joint of the first subunit A, the fourth revolute joint of the first subunit A, the fifth revolute joint of the first subunit A, and the sixth revolute joint of the first subunit A. The naming method of each folding unit contained in the first subunit A, the second subunit B, and the third subunit C is the same, which is "subunit letter + folding unit number". The naming method and position of each side of each folding unit are exactly the same, and the connection method between each folding unit is the same.

[0020] The fourth side of the reverse side of the folding unit B11 of the second subunit B is adjacent to the fourth side of the reverse side of the folding unit A2 of the first subunit A and is connected to each other through a first revolute joint. The folding unit B11 of the second subunit B can rotate inward or outward along the axis of the first revolute joint until it contacts a certain side of the folding unit A2 of the first subunit A. The third side of the auxiliary plate AB1 is adjacent to the first side of the reverse side of the folding unit B12 and is connected to each other through a second revolute joint. The auxiliary plate AB1 can rotate inward or outward along the axis of the second revolute joint until it contacts a certain side of the folding unit B12. The first side of the auxiliary plate AB2 is adjacent to the first side of the auxiliary plate AB1 and is connected to each other through a third revolute joint. The auxiliary plate AB2 can rotate inward or outward along the axis of the third revolute joint. The auxiliary plate AB2 rotates outward until it contacts one side of the auxiliary plate AB1; the third side of the auxiliary plate AB2 and the first side of the reverse side of the folding unit A3 are adjacent and connected to each other through the fourth revolute joint; the auxiliary plate AB2 can rotate inward or outward along the axis of the fourth revolute joint until it contacts one side of the folding unit A3; the second revolute joint of the first subunit A, the fifteenth revolute joint of the second subunit B, the first revolute joint, the second revolute joint, the third revolute joint, and the fourth revolute joint together constitute a spatially symmetrical six-bar linkage, which is the same as the spatially symmetrical six-bar linkage constituted by the fifth revolute joint of the first subunit A, the eighth revolute joint of the first subunit A, the ninth revolute joint of the first subunit A, the tenth revolute joint of the first subunit A, the eleventh revolute joint of the first subunit A, and the twelfth revolute joint of the first subunit A;

[0021] The fourth side of the reverse side of C11 of the third subunit C is adjacent to the fourth side of the reverse side of the folding unit B2 of the second subunit B and is connected to each other through a fifth revolute joint. C11 of the third subunit C can rotate inward or outward along the axis of the fifth revolute joint until it contacts a certain side of the folding unit B2 of the second subunit B. The third side of the auxiliary plate BC1 is adjacent to the first side of the reverse side of C12 and is connected to each other through a sixth revolute joint. The auxiliary plate BC1 can rotate inward or outward along the axis of the sixth revolute joint until it contacts a certain side of C12. The first side of the auxiliary plate BC2 is adjacent to the first side of the auxiliary plate BC1 and is connected to each other through a seventh revolute joint. The auxiliary plate BC2 can rotate inward or outward along the axis of the seventh revolute joint. The auxiliary plate BC2 moves until it contacts one of the surfaces of the auxiliary plate BC1; the third side of the auxiliary plate BC2 and the first side of the reverse side of the B3 are adjacent and connected to each other through the eighth revolute joint. The auxiliary plate BC2 can rotate inward or outward along the axis of the eighth revolute joint until it contacts one of the surfaces of the B3; the second revolute joint of the second subunit B, the fifteenth revolute joint, the fifth revolute joint, the sixth revolute joint, the seventh revolute joint, and the eighth revolute joint of the third subunit C together constitute a spatially symmetrical six-bar linkage, which is the same as the spatially symmetrical six-bar linkage constituted by the fifth revolute joint, the eighth revolute joint, the ninth revolute joint, the tenth revolute joint, the eleventh revolute joint, and the twelfth revolute joint of the first subunit A.

[0022] In a preferred embodiment: each folding unit is a plane and a folded surface or a curved surface. The four vertices of the folded quadrilateral are not located on the same plane. By arbitrarily connecting the vertices, the quadrilateral becomes two triangles, which appear as a broken line when viewed from the side. The constituent surfaces of each folding unit are approximate curved surfaces or curved surfaces. The connecting edges of each folding unit of the approximate curved surface mechanism are straight lines, and the adjacent revolute joints are located on the connecting edges. The connecting edges of each folding unit of the curved surface mechanism are curves, and several small bosses need to be added to the folding unit to support the axis of the revolute joint.

[0023] In a preferred embodiment, each of the above-mentioned revolute joints is a hinge, a hinge, or a bearing.

[0024] In a preferred embodiment: the axis between each folding unit changes along the stretching direction of the folding unit, but the relative positions between the axes of each rotating joint remain unchanged.

[0025] In a preferred embodiment: the folded state of the mechanism composed of the folding units approximates a polygonal prism.

[0026] In a preferred embodiment: the maximum opening width of the two auxiliary plates should be greater than or equal to the distance between the rotation axes of the two connected folding units in the folded state.

[0027] In a preferred embodiment: the first and fourth twist angles are less than 90°, and the second and third twist angles are greater than 90° and less than 180°.

[0028] Compared with the prior art, the present invention has the following advantages: The present invention is a deployable mechanism with a single degree of freedom. A parabolic antenna can be folded into a prism-like structure by a single drive. The folded state occupies little space. The drive can be installed at any position of the kinematic pair according to actual needs. It has strong stability during the fully unfolded, unfolded, and fully folded processes. The concave inner and outer surfaces of the mechanism can be smoothed according to actual needs. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of a single-degree-of-freedom parabolic structure with a large folding ratio; Figure 2 This is a schematic diagram showing the positional distribution of the sub-units within the mechanism; Figure 3 yes Figure 1 The back view and schematic diagram of each auxiliary plate; Figure 4 A schematic diagram of a single-degree-of-freedom parabolic structure with a large folding ratio;

[0030] Figure 5 This is a schematic diagram of the first subunit A and its folded units; Figure 6 This is a schematic diagram of the second subunit B and its folded units; Figure 7 This is a schematic diagram of the third subunit C and its folded units.

[0031] Figure 8 9 is a schematic diagram of folding unit A1 and its sides; 9 is a schematic diagram of curved surface folding unit A1 and its sides; Figure 10 This is a schematic diagram of folding unit A2 and its sides; Figure 11 This is a schematic diagram of the curved folding unit A2 and its sides; Figure 12 This is a schematic diagram of folding unit A3 and its sides; Figure 13 This is a schematic diagram of the curved folding unit A3 and its sides; Figure 14 This is a schematic diagram of folding unit A4 and its sides; Figure 15 This is a schematic diagram of the curved folding unit A4 and its sides; Figure 16 This is a schematic diagram of folding unit A5 and its sides; Figure 17 This is a schematic diagram of the curved folding unit A5 and its sides; Figure 18 This is a schematic diagram of folding unit A6 and its sides; Figure 19 This is a schematic diagram of the curved folding unit A6 and its sides; Figure 20 This is a schematic diagram of auxiliary plate AC and its sides;

[0032] Figure 21 This is the fully deployed state of the parabolic mechanism; Figure 22 It is an intermediate state in the folding process of a parabolic mechanism; Figure 23 It is an intermediate state in the folding process of a parabolic mechanism; Figure 24 It is an intermediate state in the folding process of a parabolic mechanism; Figure 25 It is the fully folded state of the parabolic mechanism;

[0033] Figure 26 It is the fully unfolded state of the parabolic surface mechanism; Figure 27 It is an intermediate state in the folding process of a parabolic surface mechanism; Figure 28 It is an intermediate state in the folding process of a parabolic surface mechanism; Figure 29 It is an intermediate state in the folding process of a parabolic surface mechanism; Figure 30 It is the fully folded state of the parabolic surface mechanism;

[0034] In the picture:

[0035] AC - auxiliary board AC, AD - auxiliary board AD, AB1 - auxiliary board AB1, AB2 - auxiliary board AB2, BC - auxiliary board BC, BD - auxiliary board BD, BC1 - auxiliary board BC1, BC2 - auxiliary board BC2, CC - auxiliary board CC, CD - auxiliary board CD;

[0036] α1 - First twist angle 1, α2 - Second twist angle 2, β1 - Third twist angle 3, β2 - Fourth twist angle 4;

[0037] A1 - Folded unit A1 of the first sub-unit A, A2 - Folded unit A2 of the first sub-unit A, A3 - Folded unit A3 of the first sub-unit A, A4 - Folded unit A4 of the first sub-unit A, A5 - Folded unit A5 of the first sub-unit A, A6 - Folded unit A6 of the first sub-unit A, A7 - Folded unit A7 of the first sub-unit A, A8 - Folded unit A8 of the first sub-unit A, A9 - Folded unit A9 of the first sub-unit A, A10 - Folded unit A10 of the first sub-unit A, A11 - Folded unit A11 of the first sub-unit A, A12 - Folded unit A12 of the first sub-unit A;

[0038] B1 - Folded unit B1 of the second subunit B, B2 - Folded unit B2 of the second subunit B, B3 - Folded unit B3 of the second subunit B, B4 - Folded unit B4 of the second subunit B, B5 - Folded unit B5 of the second subunit B, B6 - Folded unit B6 of the second subunit B, B7 - Folded unit B7 of the second subunit B, B8 - Folded unit B8 of the second subunit B, B9 - Folded unit B9 of the second subunit B, B10 - Folded unit B10 of the second subunit B, B11 - Folded unit B11 of the second subunit B, B12 - Folded unit B12 of the second subunit B;

[0039] C1 - Folded unit C1 of the third subunit C, C2 - Folded unit C2 of the third subunit C, C3 - Folded unit C3 of the third subunit C, C4 - Folded unit C4 of the third subunit C, C5 - Folded unit C5 of the third subunit C, C6 - Folded unit C6 of the third subunit C, C7 - Folded unit C7 of the third subunit C, C8 - Folded unit C8 of the third subunit C, C9 - Folded unit C9 of the third subunit C, C10 - Folded unit C10 of the third subunit C, C11 - Folded unit C11 of the third subunit C, C12 - Folded unit C12 of the third subunit C;

[0040] A1FS1 - First side of the front of the first sub-unit A folded unit A1; A1RS2 - Second side of the back of the first sub-unit A folded unit A1; A1FS3 - Third side of the front of the first sub-unit A folded unit A1.

[0041] A2FS1 - First side of the front of the first sub-unit A folded unit A2, A2RS2 - Second side of the back of the first sub-unit A folded unit A2, A2FS3 - Third side of the front of the first sub-unit A folded unit A2, A2FS4 - Fourth side of the front of the first sub-unit A folded unit A2;

[0042] A3FS1 - First side of the front of the first sub-unit A folded unit A3, A3RS2 - Second side of the back of the first sub-unit A folded unit A3, A3FS3 - Third side of the front of the first sub-unit A folded unit A3;

[0043] A4FS1 - First side of front of the first sub-unit A folded unit A4, A4RS2 - Second side of back of the first sub-unit A folded unit A4, A4FS3 - Third side of front of the first sub-unit A folded unit A4;

[0044] A5RS1 - First side of the reverse side of the first sub-unit A folded unit A5; A5FS2 - Second side of the front side of the first sub-unit A folded unit A5; A5FS3 - Third side of the front side of the first sub-unit A folded unit A5; A5FS4 - Fourth side of the front side of the first sub-unit A folded unit A5.

[0045] A6RS1 - First side of the reverse side of the first sub-unit A folded unit A6; A6FS2 - Second side of the front side of the first sub-unit A folded unit A6; A6FS3 - Third side of the front side of the first sub-unit A folded unit A6.

[0046] ACBS1 - First side of auxiliary board AC, ACBS2 - Second side of auxiliary board AC, ACBS3 - Third side of auxiliary board AC. Detailed Implementation

[0047] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0048] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0049] It should be noted that the terminology used herein is for the purpose of describing particular implementations only and is not intended to limit the exemplary implementations according to this application; as used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise; furthermore, it should be understood that when the terms “comprising” and / or “including” are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0050] like Figure 1-1 ~ Figure 3-7As shown, a parabolic single-degree-of-freedom deployable mechanism with a large folding-to-unfold ratio comprises three identical foldable sub-units and auxiliary plates connecting the sub-units. The sub-units include a first sub-unit A, a second sub-unit B, and a third sub-unit C. The auxiliary plates connecting the sub-units include auxiliary plates AB1 and AB2 between the first sub-unit A and the second sub-unit B, and auxiliary plates BC1 and BC2 between the second sub-unit B and the third sub-unit C. Each sub-unit consists of fourteen folding units. The first sub-unit A includes folding units A1, A2, A3, A4, A5, A6, A7, A8, A9, A10, A11, A12, AC, and AD. Folding units A1, A2, A3, A7, A8, and A9 are identical, while folding units A4, A5, A6, A10, A11, A12, AC, and AD are completely identical. Folding units A11 and A12 are identical. Folding units A1, A2, A3, A4, A5, and A6 are mirror symmetrical. Folding units A4, A5, A6, A7, A8, and A9 are mirror symmetrical. Folding units A7, A8, A9, A10, A11, and A12 are mirror symmetrical. Auxiliary plates AC and AD are added between the rotating joints connecting folding units A6 and A9. The second subunit B contains folding units B1, B2, B3, B4, B5, B6, B7, B8, B9, B10, B11, B12, BC, and BD. Folding units B1, B2, B3, B7, B8, and B9 are identical, while folding units B4, B5, B6, B10, B11, B12, BC, and BD are completely identical. Folding units B11 and B12 are identical. Folding units B1, B2, B3, B4, B5, and B6 are mirror symmetrical. Folding units B4, B5, B6, B7, B8, and B9 are mirror symmetrical. Folding units B7, B8, B9, B10, B11, and B12 are mirror symmetrical. Auxiliary plates BC and BD are added between the rotating joints connecting folding units B6 and B9.The third subunit C contains folding units C1, C2, C3, C4, C5, C6, C7, C8, C9, C10, C11, C12, CC, and CD. Folding units C1, C2, C3, C7, C8, and C9 are identical, while folding units C4, C5, C6, C10, C11, C12, CC, and CD are completely identical. Folding units C11 and C12 are identical. Folding units C1, C2, C3, C4, C5, and C6 are mirror symmetrical. Folding units C4, C5, C6, C7, C8, and C9 are mirror symmetrical. Folding units C7, C8, C9, C10, C11, and C12 are mirror symmetrical. Auxiliary plates CC and CD are added between the rotating joints connecting folding units C6 and C9. Auxiliary plates AB1 and AB2 connect folding units A3 and B12, and auxiliary plates BC1 and BC2 connect folding units B3 and C12. The concave surface of the deployable mechanism is called the front, and the convex surface is called the back. The crease vertices of all plates on the front are located on the same parabolic surface, and the crease vertices on the back can also be located on the same parabolic surface. Except for the auxiliary plate, the stretching direction of all folding units is parallel to the central axis of the parabola.

[0051] like Figure 2-1 As shown, in the first sub-unit A, the basic shape of the folding unit A1 is a triangle with a first twist angle 1, which is generally less than 90°. The three sides of the same face of the triangle lie on the same plane. The three sides of the front of the folding unit A1 are the first side, the second side, and the third side of the front of the folding unit A1, respectively. The three sides of the back of the folding unit A1 are the first side, the second side, and the third side of the back of the folding unit A1, respectively.

[0052] The basic shape of the folding unit A2 is a quadrilateral. Its interior angle adjacent to the first twist angle 1 of the folding unit A1 is the second twist angle 2, generally greater than 90° and less than 180°. The quadrilateral also has a third twist angle 3, greater than 90° and less than 180°. The four sides of the quadrilateral on the same face are not on the same plane. The four sides of the front of the folding unit A2 are the first side, second side, third side, and fourth side of the front of the folding unit A2. The four sides of the back of the folding unit A2 are the first side, second side, third side, and fourth side of the back of the folding unit A2. The third side of the front of the folding unit A2 is adjacent to the first side of the front of the folding unit A1 and is connected to it through the first rotating joint of the first subunit A. The folding unit A2 can rotate inward or outward along the axis of the first rotating joint of the first subunit A until it contacts one of the faces of the folding unit A1.

[0053] The basic shape of the folding unit A3 is a triangle, with its interior angle adjacent to the third twist angle 3 of the folding unit A2 being the fourth twist angle 4, generally less than 90°. The three sides of the same face of the triangle lie on the same plane. The three sides of the front of the folding unit A3 are the first side, the second side, and the third side of the front of the folding unit A3, respectively. The three sides of the back of the folding unit A3 are the first side, the second side, and the third side of the back of the folding unit A3, respectively. The third side of the front of the folding unit A3 is adjacent to the first side of the front of the folding unit A2 and is connected to each other through the second revolute joint of the first subunit A. The folding unit A3 can rotate inward or outward along the axis of the second revolute joint of the first subunit A until it contacts a certain face of the folding unit A2.

[0054] The folding unit A4 is mirror-symmetrical to the folding unit A1. The three sides of the front of the folding unit A4 are the first side, the second side, and the third side. The three sides of the back of the folding unit A4 are the first side, the second side, and the third side. The second side of the back of the folding unit A4 is adjacent to the second side of the back of the folding unit A1 and is connected to it via the third revolute joint of the first subunit A. The folding unit A4 can rotate inward or outward along the axis of the third revolute joint of the first subunit A until it contacts one of the sides of the folding unit A1.

[0055] The folding unit A5 is mirror-symmetrical to the folding unit A2. The four sides of the front of the folding unit A5 are designated as the first, second, third, and fourth sides of the front of the folding unit A5. The four sides of the back of the folding unit A5 are designated as the first, second, third, and fourth sides of the back of the folding unit A5. The third side of the front of the folding unit A5 is adjacent to the first side of the front of the folding unit A4 and is connected to it via a fourth rotating joint of the first subunit A. The folding unit A5 can rotate inward or outward along the axis of the fourth rotating joint of the first subunit A until it contacts one of the sides of the folding unit A4.

[0056] The folding unit A6 is mirror-symmetrical to the folding unit A3. The three sides of the front of the folding unit A6 are the first side, the second side, and the third side of the front of the folding unit A6, and the three sides of the back of the folding unit A6 are the first side, the second side, and the third side of the back of the folding unit A6. The third side of the front of folding unit A6 is adjacent to the first side of the front of folding unit A5 and is connected to each other through the fifth revolute joint of the first subunit A. Folding unit A6 can rotate inward or outward along the axis of the fifth revolute joint of the first subunit A until it contacts a certain side of folding unit A5. The second side of the back of folding unit A6 is adjacent to the second side of the back of folding unit A3 and is connected to each other through the sixth revolute joint of the first subunit A. Folding unit A6 can rotate inward or outward along the axis of the sixth revolute joint of the first subunit A until it contacts a certain side of folding unit A3. The first revolute joint, the second revolute joint, the third revolute joint, the fourth revolute joint, the fifth revolute joint, and the sixth revolute joint of the first subunit A together constitute a spatially symmetrical six-bar linkage.

[0057] The folding unit A7 is exactly the same as the folding unit A1. The positions of all its sides are the same as those of the folding unit A1.

[0058] The folding unit A8 is identical to the folding unit A2. The positions of its sides are the same as those of the folding unit A2. The third side of the front of the folding unit A8 is adjacent to the first side of the front of the folding unit A7 and is connected to each other through the seventh revolute joint of the first subunit A. The folding unit A8 can rotate inward or outward along the axis of the seventh revolute joint of the first subunit A until it contacts a face of the folding unit A7. The fourth side of the reverse side of the folding unit A8 is adjacent to the fourth side of the reverse side of the folding unit A5 and is connected to each other through the eighth revolute joint of the first subunit A. The folding unit A8 can rotate inward or outward along the axis of the eighth revolute joint of the first subunit A until it contacts a face of the folding unit A5.

[0059] The folding unit A9 is exactly the same as the folding unit A3. The positions of its sides are the same as those of the folding unit A3; the third side of the front of the folding unit A9 and the first side of the front of the folding unit A8 are adjacent and connected to each other through the ninth rotating joint of the first subunit A. The folding unit A9 can rotate inward or outward along the axis of the ninth rotating joint of the first subunit A until it contacts a certain side of the folding unit A8.

[0060] like Figure 3-7 As shown, the basic shape of the auxiliary plate AC is a right-angled triangular prism, and the three sides of the auxiliary plate AC are the first side, the second side, and the third side. The third side of the auxiliary plate AC is adjacent to the first side of the reverse side of the folding unit A6 and is connected to each other through the tenth revolute joint of the first subunit A. The auxiliary plate AC can rotate inward or outward along the axis of the tenth revolute joint of the first subunit A until it contacts a certain side of the folding unit A6.

[0061] The auxiliary plates AD and AC are identical, as are the auxiliary plates AB1, AB2, BC1, and BC2 described below. The first side of auxiliary plate AD is adjacent to the first side of auxiliary plate AC and connected to each other via the eleventh revolute joint of the first subunit A. Auxiliary plate AD can rotate inward or outward along the axis of the eleventh revolute joint of the first subunit A until it contacts one side of auxiliary plate AC. The third side of auxiliary plate AD is adjacent to the first side of the reverse side of folding unit A9 and connected to each other via the twelfth revolute joint of the first subunit A. Auxiliary plate AD can rotate inward or outward along the axis of the twelfth revolute joint of the first subunit A until it contacts one side of folding unit A9. The fifth, eighth, ninth, tenth, eleventh, and twelfth revolute joints of the first subunit A together constitute a spatially symmetrical six-bar linkage.

[0062] The folding unit A10 is exactly the same as the folding unit A4. The positions of its sides are the same as those of the folding unit A4; the second side of the reverse side of the folding unit A10 and the second side of the reverse side of the folding unit A7 are adjacent and connected to each other through the thirteenth revolute joint of the first subunit A. The folding unit A10 can rotate inward or outward along the axis of the thirteenth revolute joint of the first subunit A until it contacts a certain side of the folding unit A7.

[0063] The folding unit A11 is exactly the same as the folding unit A5. The positions of its sides are the same as those of the folding unit A5; the third side of the front of the folding unit A11 is adjacent to the first side of the front of the folding unit A10 and is connected to each other through the fourteenth revolute joint of the first subunit A. The folding unit A11 can rotate inward or outward along the axis of the fourteenth revolute joint of the first subunit A until it contacts a certain side of the folding unit A10.

[0064] The folding unit A12 is identical to the folding unit A6. The positions of its sides are consistent with those of the folding unit A6. The third side of the front of the folding unit A12 is adjacent to the first side of the front of the folding unit A11 and is connected to each other through the fifteenth revolute joint of the first subunit A. The folding unit A12 can rotate inward or outward along the axis of the fifteenth revolute joint of the first subunit A until it contacts one side of the folding unit A11. The second side of the reverse side of the folding unit A12 is adjacent to the second side of the reverse side of the folding unit A9 and is connected to each other through the sixteenth revolute joint of the first subunit A. The folding unit A12 can rotate inward or outward along the axis of the sixteenth revolute joint of the first subunit A. The component rotates outward until it contacts one of the faces of the folding unit A9. The seventh, ninth, thirteenth, fourteenth, fifteenth, and sixteenth revolute joints of the first subunit A together constitute a spatially symmetrical six-bar linkage, which is the same as the spatially symmetrical six-bar linkage constituted by the first, second, third, fourth, fifth, and sixth revolute joints of the first subunit A. The folding units contained in the first subunit ABC are named in the same way, using "subunit letter + folding unit number". The naming and position of each side of each folding unit are completely identical, and the connection methods between the folding units are the same. There are two types of mechanisms formed by the revolute joints. One type is a spatially symmetrical six-bar linkage formed by the first revolute joint of the first subunit A, the second revolute joint of the first subunit A, the third revolute joint of the first subunit A, the fourth revolute joint of the first subunit A, the fifth revolute joint of the first subunit A, and the sixth revolute joint of the first subunit A. The other type is a spatially symmetrical six-bar linkage formed by the fifth revolute joint of the first subunit A, the eighth revolute joint of the first subunit A, the ninth revolute joint of the first subunit A, the tenth revolute joint of the first subunit A, the eleventh revolute joint of the first subunit A, and the twelfth revolute joint of the first subunit A.

[0065] The fourth side of the reverse side of the folding unit B11 of the second subunit B is adjacent to the fourth side of the reverse side of the folding unit A2 of the first subunit A and is connected to each other through a first revolute joint. The folding unit B11 of the second subunit B can rotate inward or outward along the axis of the first revolute joint until it contacts a certain side of the folding unit A2 of the first subunit A. The third side of the auxiliary plate AB1 is adjacent to the first side of the reverse side of the folding unit B12 and is connected to each other through a second revolute joint. The auxiliary plate AB1 can rotate inward or outward along the axis of the second revolute joint until it contacts a certain side of the folding unit B12. The first side of the auxiliary plate AB2 is adjacent to the first side of the auxiliary plate AB1 and is connected to each other through a third revolute joint. The auxiliary plate AB2 can rotate inward or outward along the axis of the third revolute joint. The auxiliary plate AB2 rotates outward until it contacts one side of the auxiliary plate AB1; the third side of the auxiliary plate AB2 and the first side of the reverse side of the folding unit A3 are adjacent and connected to each other through the fourth revolute joint. The auxiliary plate AB2 can rotate inward or outward along the axis of the fourth revolute joint until it contacts one side of the folding unit A3; the second revolute joint of the first subunit A, the fifteenth revolute joint of the second subunit B, the first revolute joint, the second revolute joint, the third revolute joint, and the fourth revolute joint together constitute a spatially symmetrical six-bar linkage, which is the same as the spatially symmetrical six-bar linkage constituted by the fifth revolute joint of the first subunit A, the eighth revolute joint of the first subunit A, the ninth revolute joint of the first subunit A, the tenth revolute joint of the first subunit A, the eleventh revolute joint of the first subunit A, and the twelfth revolute joint of the first subunit A.

[0066] The fourth side of the reverse side of the folding unit C11 of the third subunit C is adjacent to the fourth side of the reverse side of the folding unit B2 of the second subunit B and is connected to each other through a fifth revolute joint. The folding unit C11 of the third subunit C can rotate inward or outward along the axis of the fifth revolute joint until it contacts a certain side of the folding unit B2 of the second subunit B. The third side of the auxiliary plate BC1 is adjacent to the first side of the reverse side of the folding unit C12 and is connected to each other through a sixth revolute joint. The auxiliary plate BC1 can rotate inward or outward along the axis of the sixth revolute joint until it contacts a certain side of the folding unit C12. The first side of the auxiliary plate BC2 is adjacent to the first side of the auxiliary plate BC1 and is connected to each other through a seventh revolute joint. The auxiliary plate BC2 can rotate inward or outward along the axis of the seventh revolute joint. The auxiliary plate BC2 rotates outward until it contacts one side of the auxiliary plate BC1; the third side of the auxiliary plate BC2 and the first side of the reverse side of the folding unit B3 are adjacent and connected to each other through the eighth revolute joint. The auxiliary plate BC2 can rotate inward or outward along the axis of the eighth revolute joint until it contacts one side of the folding unit B3; the second revolute joint of the second subunit B, the fifteenth revolute joint, the fifth revolute joint, the sixth revolute joint, the seventh revolute joint, and the eighth revolute joint of the third subunit C together constitute a spatially symmetrical six-bar linkage, which is the same as the spatially symmetrical six-bar linkage constituted by the fifth revolute joint, the eighth revolute joint, the ninth revolute joint, the tenth revolute joint, the eleventh revolute joint, and the twelfth revolute joint of the first subunit A.

[0067] The specific unfolding process is as follows: Figure 4-1 ~ Figure 5-5 As shown, Figure 4-1 and Figure 5-1 This is the fully deployed state of the parabolic mechanism; Figure 4-2 ~ Figure 4-4 and Figure 5-2 ~ Figure 5-4 It is an intermediate state in the folding process of a parabolic mechanism; Figure 4-5 and Figure 5-5 This is the fully folded state of the parabolic mechanism. The unfolded state of this example can be an approximate curved surface or a curved surface, and after folding, it roughly presents the shape of a polygonal prism, making it easy to store and use.

[0068] All revolute joints are hinges, pivots, or bearings; the length of the revolute joint is unlimited, and the size of the boss in the curved surface mechanism is unlimited, as long as it does not affect the formation of a closed-loop revolute joint.

[0069] The axis between each folding unit can be changed along the stretching direction of the folding unit, but the relative position between the axes of each rotating joint remains unchanged.

[0070] The maximum opening width of the two auxiliary plates should be greater than or equal to the distance between the rotation axes of the two connected folding units in the folded state.

[0071] The first twist angle 1 and the fourth twist angle 4 are generally less than 90°, while the second twist angle 2 and the third twist angle 3 are generally greater than 90° and less than 180°. The first twist angles 1 to 4 are determined according to the required unit size; by changing their values, the entire unit size can be adjusted.

[0072] As long as the above constraints are met, the parabolic mechanism can be unfolded. Each unit can be modified in size, shape, material, etc., according to actual needs. It should be noted that interference should be avoided during the unfolding process.

Claims

1. A single-degree-of-freedom parabolic structure with a large folding ratio, characterized in that: It comprises three identical foldable sub-units and auxiliary plates connecting the sub-units; the sub-units include a first sub-unit A, a second sub-unit B, and a third sub-unit C; the auxiliary plates connecting the sub-units include auxiliary plates AB1 and AB2 between the first sub-unit A and the second sub-unit B, and auxiliary plates BC1 and BC2 between the second sub-unit B and the third sub-unit C; each sub-unit consists of fourteen folding units; the first sub-unit A includes folding units A1, A2, A3, A4, A5, A6, A7, and [other folding units]. Folding units A8, A9, A10, A11, A12, AC, and AD are provided. Folding units A1, A2, and A3 are identical to folding units A7, A8, and A9, respectively. Folding units A4, A5, and A6 are identical to folding units A10, A11, and A12, respectively. Folding units A1, A2, and A3 are mirror-symmetric to folding units A4, A5, and A6, respectively. Folding units A4, A5, and A6 are mirror-symmetric to folding units A7, A8, and A9, respectively. Folding units A7, A8, and A9 are mirror-symmetric to folding units A10, A11, and A12, respectively. Auxiliary plates AC and AD are added between the rotating joints connecting folding units A6 and A9. The second subunit B contains folding units B1, B2, B3, B4, B5, B6, B7, B8, B9, B10, B11, B12, BC, and BD. Folding units B1, B2, and B3 are identical to folding units B7, B8, and B9, respectively. Folding units B4, B5, and B6 are identical to folding units B10, B11, and B12, respectively. Folding units B1, B2, and B3 are also identical to... Folding units B4, B5, and B6 are mirror-symmetric. Folding units B4, B5, and B6 are mirror-symmetric with folding units B7, B8, and B9, respectively. Folding units B7, B8, and B9 are mirror-symmetric with folding units B10, B11, and B12, respectively. Auxiliary plates BC and BD are added between the rotating joints connecting folding units B6 and B9. The third subunit C contains folding units C1, C2, C3, C4, C5, C6, C7, C8, C9, and C11.

10. Folding unit C11, folding unit C12, folding unit CC, and folding unit CD, wherein folding unit C1, folding unit C2, and folding unit C3 are identical to folding units C7, C8, and C9 respectively; folding unit C4, folding unit C5, and folding unit C6 are identical to folding units C10, folding unit C11, and folding unit C12 respectively; folding unit C1, folding unit C2, and folding unit C3 are mirror symmetrical to folding units C4, folding unit C5, and folding unit C6 respectively; and folding unit C4, folding unit C5, and folding unit C6 are mirror symmetrical to folding units C7, folding unit C8, and folding unit C9 respectively. Folding units C7, C8, and C9 are mirror-symmetrical to folding units C10, C11, and C12, respectively. Auxiliary plates CC and CD are added between the rotating joints connecting folding units C6 and C9. Auxiliary plates AB1 and AB2 connect folding units A3 and B12, while auxiliary plates BC1 and BC2 connect folding units B3 and C12. The concave surface of the deployable mechanism is called the front, and the convex surface is called the back. The crease vertices of all plates on the front and back sides are located on the same parabolic surface. Except for the auxiliary plates, the stretching direction of all folding units is parallel to the central axis of the parabolic surface. In the first subunit A, the basic shape of the folding unit A1 is a triangle with a first twist angle of less than 90°, and the three sides of the same face of the triangle are located on the same plane; the three sides of the front of the folding unit A1 are the first side of the front of the folding unit A1, the second side of the front of the folding unit A1, and the third side of the front of the folding unit A1, and the three sides of the back of the folding unit A1 are the first side of the back of the folding unit A1, the second side of the back of the folding unit A1, and the third side of the back of the folding unit A1. The basic shape of the folding unit A2 is a quadrilateral. Adjacent to the first twist angle of the folding unit A1 is the second twist angle, which is greater than 90° and less than 180°. The quadrilateral also has a third twist angle, greater than 90° and less than 180°. The four sides of the quadrilateral on the same face are not on the same plane. The four sides of the front of the folding unit A2 are the first side, second side, third side, and fourth side of the front of the folding unit A2. The four sides of the back of the folding unit A2 are the first side, second side, third side, and fourth side of the back of the folding unit A2. The third side of the front of the folding unit A2 is adjacent to the first side of the front of the folding unit A1 and is connected to it through the first rotating joint of the first subunit A. The folding unit A2 can rotate inward or outward along the axis of the first rotating joint of the first subunit A until it contacts one of the faces of the folding unit A1. The basic shape of the folding unit A3 is a triangle, and the fourth twist angle adjacent to the third twist angle of the folding unit A2 is less than 90°. The three sides of the same face of the triangle are located on the same plane. The three sides of the front of the folding unit A3 are the first side, the second side, and the third side of the front of the folding unit A3. The three sides of the back of the folding unit A3 are the first side, the second side, and the third side of the back of the folding unit A3. The third side of the front of the folding unit A3 is adjacent to the first side of the front of the folding unit A2 and is connected to each other through the second revolute joint of the first subunit A. The folding unit A3 can rotate inward or outward along the axis of the second revolute joint of the first subunit A until it contacts a certain face of the folding unit A2. The folding unit A4 is mirror-symmetrical to the folding unit A1. The three sides of the front of the folding unit A4 are the first side, the second side, and the third side of the front of the folding unit A4, and the three sides of the back of the folding unit A4 are the first side, the second side, and the third side of the back of the folding unit A4. The second side of the back of the folding unit A4 is adjacent to the second side of the back of the folding unit A1 and is connected to each other through the third rotating joint of the first subunit A. The folding unit A4 can rotate inward or outward along the axis of the third rotating joint of the first subunit A until it contacts a certain side of the folding unit A1. The folding unit A5 is mirror-symmetrical to the folding unit A2. The four sides of the front of the folding unit A5 are the first side, the second side, the third side, and the fourth side of the front of the folding unit A5, respectively. The four sides of the back of the folding unit A5 are the first side, the second side, the third side, and the fourth side of the back of the folding unit A5, respectively. The third side of the front of the folding unit A5 is adjacent to the first side of the front of the folding unit A4 and is connected to each other through the fourth rotating joint of the first subunit A. The folding unit A5 can rotate inward or outward along the axis of the fourth rotating joint of the first subunit A until it contacts a certain side of the folding unit A4. The folding unit A6 is mirror-symmetrical to the folding unit A3; the three sides of the front of the folding unit A6 are the first side, the second side, and the third side of the front of the folding unit A6, and the three sides of the back of the folding unit A6 are the first side, the second side, and the third side of the back of the folding unit A6; the third side of the front of the folding unit A6 is adjacent to the first side of the front of the folding unit A5 and is connected to each other through the fifth rotating joint of the first subunit A; the folding unit A6 can move inward or outward along the axis of the fifth rotating joint of the first subunit A. The folding unit A6 rotates outward until it contacts one of the faces of the folding unit A5. The second side of the reverse face of the folding unit A6 is adjacent to the second side of the reverse face of the folding unit A3 and is connected to each other through the sixth revolute joint of the first subunit A. The folding unit A6 can rotate inward or outward along the axis of the sixth revolute joint of the first subunit A until it contacts one of the faces of the folding unit A3. The first revolute joint, the second revolute joint, the third revolute joint, the fourth revolute joint, the fifth revolute joint, and the sixth revolute joint of the first subunit A together constitute a spatially symmetrical six-bar linkage. The folding unit A7 is exactly the same as the folding unit A1; the positions of its sides are the same as those of the folding unit A1. The folding unit A8 is identical to the folding unit A2; the positions of its sides are consistent with those of the folding unit A2; the third side of the front of the folding unit A8 is adjacent to the first side of the front of the folding unit A7 and is connected to each other through the seventh revolute joint of the first subunit A; the folding unit A8 can rotate inward or outward along the axis of the seventh revolute joint of the first subunit A until it contacts a certain side of the folding unit A7; the fourth side of the reverse side of the folding unit A8 is adjacent to the fourth side of the reverse side of the folding unit A5 and is connected to each other through the eighth revolute joint of the first subunit A; the folding unit A8 can rotate inward or outward along the axis of the eighth revolute joint of the first subunit A until it contacts a certain side of the folding unit A5. The folding unit A9 is exactly the same as the folding unit A3; the positions of its sides are the same as those of the folding unit A3; the third side of the front of the folding unit A9 and the first side of the front of the folding unit A8 are adjacent and connected to each other through the ninth rotating joint of the first subunit A; the folding unit A9 can rotate inward or outward along the axis of the ninth rotating joint of the first subunit A until it contacts a certain side of the folding unit A8. The basic shape of the auxiliary plate AC is an equilateral right-angled triangular prism. The three sides of the auxiliary plate AC are the first side, the second side, and the third side. The third side of the auxiliary plate AC is adjacent to the first side of the reverse side of the folding unit A6 and is connected to each other through the tenth rotation joint of the first subunit A. The auxiliary plate AC can rotate inward or outward along the axis of the tenth rotation joint of the first subunit A until it contacts a certain side of the folding unit A6. The auxiliary plate AD and auxiliary plate AC are completely identical. The auxiliary plates AB1, AB2, BC1, and BC2 described below are also completely identical to auxiliary plate AC. The first side of auxiliary plate AD is adjacent to the first side of auxiliary plate AC and connected to each other through the eleventh revolute joint of the first subunit A. Auxiliary plate AD can rotate inward or outward along the axis of the eleventh revolute joint of the first subunit A until it contacts one side of auxiliary plate AC. The third side of auxiliary plate AD is adjacent to the first side of the reverse side of folding unit A9 and connected to each other through the twelfth revolute joint of the first subunit A. Auxiliary plate AD can rotate inward or outward along the axis of the twelfth revolute joint of the first subunit A until it contacts one side of folding unit A9. The fifth, eighth, ninth, tenth, eleventh, and twelfth revolute joints of the first subunit A together constitute a spatially symmetrical six-bar linkage. The folding unit A10 is exactly the same as the folding unit A4; the positions of each side of the folding unit A10 are the same as those of the folding unit A4; the second side of the reverse side of the folding unit A10 and the second side of the reverse side of the folding unit A7 are adjacent and connected to each other through the thirteenth rotating joint of the first subunit A; the folding unit A10 can rotate inward or outward along the axis of the thirteenth rotating joint of the first subunit A until it contacts a certain side of the folding unit A7. The folding unit A11 is exactly the same as the folding unit A5; the positions of each side of the folding unit A11 are consistent with the positions of the folding unit A5; the third side of the front of the folding unit A11 and the first side of the front of the folding unit A10 are adjacent and connected to each other through the fourteenth rotating joint of the first subunit A; the folding unit A11 can rotate inward or outward along the axis of the fourteenth rotating joint of the first subunit A until it contacts a certain side of the folding unit A10. The folding unit A12 is identical to the folding unit A6; the positions of its sides are consistent with those of the folding unit A6; the third side of the front of the folding unit A12 is adjacent to the first side of the front of the folding unit A11 and is connected to each other through the fifteenth revolute joint of the first subunit A; the folding unit A12 can rotate inward or outward along the axis of the fifteenth revolute joint of the first subunit A until it contacts a certain side of the folding unit A11; the second side of the reverse side of the folding unit A12 is adjacent to the second side of the reverse side of the folding unit A9 and is connected to each other through the sixteenth revolute joint of the first subunit A; the folding unit A12 can rotate inward or outward along the axis of the sixteenth revolute joint of the first subunit A until it contacts a certain side of the folding unit A9; the seventh side of the first subunit A... The revolute joints, the ninth revolute joint of the first subunit A, the thirteenth revolute joint of the first subunit A, the fourteenth revolute joint of the first subunit A, the fifteenth revolute joint of the first subunit A, and the sixteenth revolute joint of the first subunit A together constitute a spatially symmetrical six-bar linkage, which is the same as the spatially symmetrical six-bar linkage constituted by the first revolute joint of the first subunit A, the second revolute joint of the first subunit A, the third revolute joint of the first subunit A, the fourth revolute joint of the first subunit A, the fifth revolute joint of the first subunit A, and the sixth revolute joint of the first subunit A. The naming method of each folding unit contained in the first subunit A, the second subunit B, and the third subunit C is the same, which is "subunit letter + folding unit number". The naming method and position of each side of each folding unit are exactly the same, and the connection method between each folding unit is the same. The fourth side of the reverse side of the folding unit B11 of the second subunit B is adjacent to the fourth side of the reverse side of the folding unit A2 of the first subunit A and is connected to each other through a first revolute joint. The folding unit B11 of the second subunit B can rotate inward or outward along the axis of the first revolute joint until it contacts a certain side of the folding unit A2 of the first subunit A. The third side of the auxiliary plate AB1 is adjacent to the first side of the reverse side of the folding unit B12 and is connected to each other through a second revolute joint. The auxiliary plate AB1 can rotate inward or outward along the axis of the second revolute joint until it contacts a certain side of the folding unit B12. The first side of the auxiliary plate AB2 is adjacent to the first side of the auxiliary plate AB1 and is connected to each other through a third revolute joint. The auxiliary plate AB2 can rotate inward or outward along the axis of the third revolute joint. The auxiliary plate AB2 rotates outward until it contacts one side of the auxiliary plate AB1; the third side of the auxiliary plate AB2 and the first side of the reverse side of the folding unit A3 are adjacent and connected to each other through the fourth revolute joint; the auxiliary plate AB2 can rotate inward or outward along the axis of the fourth revolute joint until it contacts one side of the folding unit A3; the second revolute joint of the first subunit A, the fifteenth revolute joint of the second subunit B, the first revolute joint, the second revolute joint, the third revolute joint, and the fourth revolute joint together constitute a spatially symmetrical six-bar linkage, which is the same as the spatially symmetrical six-bar linkage constituted by the fifth revolute joint of the first subunit A, the eighth revolute joint of the first subunit A, the ninth revolute joint of the first subunit A, the tenth revolute joint of the first subunit A, the eleventh revolute joint of the first subunit A, and the twelfth revolute joint of the first subunit A; The fourth side of the reverse side of C11 of the third subunit C is adjacent to the fourth side of the reverse side of the folding unit B2 of the second subunit B and is connected to each other through a fifth revolute joint. C11 of the third subunit C can rotate inward or outward along the axis of the fifth revolute joint until it contacts a certain side of the folding unit B2 of the second subunit B. The third side of the auxiliary plate BC1 is adjacent to the first side of the reverse side of C12 and is connected to each other through a sixth revolute joint. The auxiliary plate BC1 can rotate inward or outward along the axis of the sixth revolute joint until it contacts a certain side of C12. The first side of the auxiliary plate BC2 is adjacent to the first side of the auxiliary plate BC1 and is connected to each other through a seventh revolute joint. The auxiliary plate BC2 can rotate inward or outward along the axis of the seventh revolute joint. The auxiliary plate BC2 moves until it contacts one of the surfaces of the auxiliary plate BC1; the third side of the auxiliary plate BC2 and the first side of the reverse side of the B3 are adjacent and connected to each other through the eighth revolute joint. The auxiliary plate BC2 can rotate inward or outward along the axis of the eighth revolute joint until it contacts one of the surfaces of the B3; the second revolute joint of the second subunit B, the fifteenth revolute joint, the fifth revolute joint, the sixth revolute joint, the seventh revolute joint, and the eighth revolute joint of the third subunit C together constitute a spatially symmetrical six-bar linkage, which is the same as the spatially symmetrical six-bar linkage constituted by the fifth revolute joint, the eighth revolute joint, the ninth revolute joint, the tenth revolute joint, the eleventh revolute joint, and the twelfth revolute joint of the first subunit A.

2. The single-degree-of-freedom parabolic structure with a large folding ratio according to claim 1, characterized in that: Each folding unit is a plane and a folded or curved surface. The four vertices of the folded quadrilateral are not located on the same plane. By arbitrarily connecting the vertices, the quadrilateral becomes two triangles. When viewed from the side, it presents a broken line. The constituent surfaces of each folding unit are approximate curved surfaces or curved surfaces. The connecting edges of each folding unit of the approximate curved surface mechanism are straight lines, and its adjacent revolute joints are located on the connecting edges. The connecting edges of each folding unit of the curved surface mechanism are curves, and several small bosses need to be added to the folding unit to support the axis of the revolute joint.

3. The single-degree-of-freedom parabolic structure with a large folding ratio according to claim 1, characterized in that: The rotating pair is a hinge, a hinge assembly, or a bearing.

4. A single-degree-of-freedom parabolic structure with a large folding ratio according to claim 1, characterized in that: The axis between each folding unit changes along the stretching direction of the folding unit, but the relative position between the axes of each rotating joint remains unchanged.

5. A single-degree-of-freedom parabolic structure with a large folding ratio according to claim 1, characterized in that: The folded state of the mechanism composed of the folding units approximates a polygonal prism.

6. A single-degree-of-freedom parabolic structure with a large folding ratio according to claim 1, characterized in that: The maximum opening width of the two auxiliary plates should be greater than or equal to the distance between the rotation axes of the two folding units connected to them in the folded state.

7. A single-degree-of-freedom parabolic structure with a large folding ratio according to claim 1, characterized in that: The first and fourth torsion angles are less than 90°, while the second and third torsion angles are greater than 90° and less than 180°.

Images