Arc-shaped unit and arc-shaped protection structure

Abstract

The application relates to an arc-shaped unit, which comprises a first arc-shaped side plate, a second arc-shaped side plate and an intermediate plate layer, the bending directions of the first arc-shaped side plate and the second arc-shaped side plate are the same, the intermediate plate layer has an arc-shaped Miura-origami derived structure, and the arc-shaped Miura-origami derived structure forms at least one level of support structure between the first arc-shaped side plate and the second arc-shaped side plate. The application also relates to an arc-shaped protection structure, which comprises an arc-shaped flexible substrate and a plurality of arc-shaped units as described above, and the arc-shaped units are laid on at least one side surface of the arc-shaped flexible substrate. The application designs the arc-shaped unit and the arc-shaped protection structure capable of being used for arc-shaped object protection based on the Miura-origami, a reasonable crushing mode is formed by using the at least one level of support structure, impact force can be effectively dispersed in time, the protection performance is greatly improved while the structural flexibility is maintained, and the arc-shaped unit and the arc-shaped protection structure have the characteristics of light weight.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of protective equipment, in particular to an arc-shaped unit and an arc-shaped protective structure. BACKGROUND

[0002] Protective equipment such as armor can be used to protect the human body or designated parts from injury caused by external forces or object impact. In order to facilitate the movement of flexible protective objects, protective equipment needs to have a certain flexibility in addition to protective performance. However, there is often a contradiction between protective performance and flexibility in the design of protective equipment. In order to ensure protective performance, hard plates are generally used, which not only makes the protective structure more cumbersome, but also affects flexibility. Therefore, due to the need for flexibility, some protective equipment often does not have protective structures at joints such as shoulders and knees or has insufficient independent protection, which greatly reduces the protective performance at the connection. Therefore, it is necessary to design a lightweight protective structure that can match the arc-shaped object and improve the protective performance while maintaining structural flexibility. SUMMARY

[0003] In view of the above technical problems, the present application provides an arc-shaped unit and an arc-shaped protective structure, which can be used for arc-shaped object protection, improve the protective performance while maintaining structural flexibility, and have the characteristics of lightweight.

[0004] To solve the above technical problems, the present application provides an arc-shaped unit, which comprises a first arc-shaped side plate, a second arc-shaped side plate and an intermediate plate layer, the bending directions of the first arc-shaped side plate and the second arc-shaped side plate are the same, the intermediate plate layer has an arc-shaped Miura fold derived structure, and the arc-shaped Miura fold derived structure forms at least one level of support structure between the first arc-shaped side plate and the second arc-shaped side plate.

[0005] Optionally, the arc-shaped Miura fold derived structure comprises a plurality of arc-shaped unit cells connected in an array, each of the arc-shaped unit cells has two support parts that can be folded relative to each other; in the folded state, each of the support parts forms at least one level of support structure and is supported at both ends on the first arc-shaped side plate and the second arc-shaped side plate.

[0006] Optionally, in the planar state, the arc-shaped unit cell has straight line creases parallel to each other, and a middle zigzag crease and a side zigzag crease arranged along the extension direction of the straight line creases, the middle zigzag crease divides the arc-shaped unit cell into two support parts, and the corresponding top angles between the middle zigzag crease and the side zigzag crease are not equal.

[0007] Optionally, the straight line creases are equal in length and are arranged at equal intervals, and the two parts formed by the middle zigzag crease and located on the side of the straight line crease are equal in length.

[0008] Optionally, no sawtooth creases are arranged between the middle sawtooth creases and the side sawtooth creases corresponding to the support portions to form a one-level support structure, or an even number of derived sawtooth creases are arranged along the extension direction of the straight creases to form at least a two-level support structure; the two edges of all the sawtooth creases are symmetrically located on the middle straight creases.

[0009] Optionally, in the folded state, the vertex angles corresponding to the end portions of the side sawtooth creases, the vertex angles formed by folding the side sawtooth creases, the vertex angles corresponding to the end portions of the middle sawtooth creases, and the vertex angles formed by folding the middle sawtooth creases are respectively located on a cylindrical surface, and all the cylindrical surfaces are coaxial.

[0010] Optionally, the distance between the vertex angle and the axis corresponding to the cylindrical surface satisfies the following relationship:

[0011] r3-r1-t1 / 2≤t2 / 2;

[0012] r4-r2-t1 / 2≤t2 / 2;

[0013] wherein r1 is the radius of the cylindrical surface on which the vertex angle corresponding to the end portion of the side sawtooth crease is located; r2 is the radius of the cylindrical surface on which the vertex angle corresponding to the end portion of the middle sawtooth crease is located; r3 is the radius of the cylindrical surface on which the vertex angle formed by folding the side sawtooth crease is located; r4 is the radius of the cylindrical surface on which the vertex angle formed by folding the middle sawtooth crease is located; t1 is the thickness of the arc-shaped unit cell; and t2 is the thickness of the first arc-shaped side plate or the second arc-shaped side plate.

[0014] Optionally, the first arc-shaped side plate, the second arc-shaped side plate, and the middle plate layer are integrally formed.

[0015] The application also provides an arc-shaped protective structure, comprising an arc-shaped flexible substrate and a plurality of arc-shaped units as described above, the arc-shaped units being laid on at least one side surface of the arc-shaped flexible substrate.

[0016] Optionally, the arc-shaped units are periodically arranged and staggered and overlapped with each other.

[0017] The application relates to an arc-shaped unit, comprising a first arc-shaped side plate, a second arc-shaped side plate and an intermediate plate layer, the bending directions of the first arc-shaped side plate and the second arc-shaped side plate are the same, the intermediate plate layer has an arc-shaped Miura-origami derived structure, and the arc-shaped Miura-origami derived structure forms at least one level of support structure between the first arc-shaped side plate and the second arc-shaped side plate. The application also relates to an arc-shaped protection structure, comprising an arc-shaped flexible substrate and a plurality of arc-shaped units as described above, and the arc-shaped units are laid on at least one side surface of the arc-shaped flexible substrate. The application designs the arc-shaped unit and the arc-shaped protection structure which can be used for arc-shaped object protection based on the Miura-origami, and the reasonable crushing mode is formed by the at least one level of support structure, so that the impact force can be effectively dispersed in time, and the protection performance is greatly improved while the structural flexibility is maintained. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is one of the structural schematic diagrams of the arc-shaped unit according to the first embodiment;

[0019] Figure 2 is the second structural schematic diagram of the arc-shaped unit according to the first embodiment;

[0020] Figure 3 is the design explanatory diagram of the arc-shaped unit with one level of support structure according to the first embodiment;

[0021] Figure 4 is the design explanatory diagram of the arc-shaped unit with two levels of support structure according to the first embodiment;

[0022] Figure 5 is the comparison diagram of the arc-shaped unit with one level of support structure and the arc-shaped unit with two levels of support structure according to the first embodiment;

[0023] Figure 6 is one of the structural schematic diagrams of the arc-shaped protection structure according to the second embodiment;

[0024] Figure 7 is the second structural schematic diagram of the arc-shaped protection structure according to the second embodiment;

[0025] Figure 8 is the third structural schematic diagram of the arc-shaped protection structure according to the second embodiment. DETAILED DESCRIPTION

[0026] The implementation manners of the application are described below by specific specific embodiments, and other advantages and effects of the application can be easily understood by those skilled in the art according to the content disclosed in the description.

[0027] In the following description, reference is made to the accompanying drawings which form a part hereof, and which is shown by way of illustration of several embodiments of the present application. It is understood that other embodiments can be utilized and mechanical, structural, electrical, and operational changes can be made without departing from the spirit and scope of the present application. The following detailed description is, therefore, not to be taken in a limiting sense, as the scope of the present application is defined by the appended claims, along with the full scope of equivalents to which such claims are entitled.

[0028] While in some examples the terms first, second, etc. are used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another.

[0029] Also, as used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises", "comprising", "includes" and / or "including" when used herein, specify the presence of stated features, steps, operations, elements, components, items, and / or groups but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, items, and / or groups thereof. As used herein, the term "or" and "and / or" is construed to be inclusive, or means one and / or any combination of items. Thus, "A, B, or C" or "A, B, and / or C" means "any of the following: A; B; C; A and B; A and C; B and C; A, B, and C". Exceptions to this definition will only be present when the combination of elements, functions, steps, or actions are mutually exclusive from each other in their nature.

[0030] First embodiment

[0031] Figure 1 is one of the structural schematic diagrams of the arc-shaped unit according to the first embodiment; Figure 2 is another structural schematic diagram of the arc-shaped unit according to the first embodiment. As shown in Figure 1 and Figure 2 As shown, the arc-shaped unit of the embodiment includes a first arc-shaped side plate 11, a second arc-shaped side plate 12, and a middle plate layer 13. The first arc-shaped side plate 11 and the second arc-shaped side plate 12 have the same bending direction, and the middle plate layer 13 has an arc-shaped Miura-origami derived structure.

[0032] The middle plate layer 13 of the present application adopts an arc-shaped Miura-origami derived structure, which can simultaneously achieve optimization of strength and energy absorption. In addition, compared with a relatively dense structure, the weight of the arc-shaped unit can be reduced, and the arc-shaped unit has the characteristics of lightweight.

[0033] The middle plate layer 13 includes a plurality of arc-shaped unit cells connected in an array to form an arc-shaped Miura-origami derived structure. Figure 3 (a) is a schematic diagram of a traditional Miura-origami unit cell in a folded state; Figure 3(b) is a schematic diagram of the arc-shaped unit cell in this embodiment in a planar state; Figure 3 (c) is a schematic diagram of the arc-shaped unit cells arranged and connected along one direction in this embodiment. Figure 3 As shown in (a), a traditional Miura origami unit cell consists of four creases intersecting at a single point. The flat paper is divided into four parallelogram panels with acute angles α1. Miura origami unit cells can be arranged in an infinite array to form a periodic structure. The traditional Miura origami structure consists of parallel straight creases and serrated creases. The serrated creases are distributed along the direction of the straight creases in alternating mountain creases and valley creases, and are parallel to each other in the planar state. Figure 3 In (a), the solid and dashed lines represent mountain folds and valley folds, respectively. In the folded three-dimensional structure, the vertices lie on two parallel planes, the distance between the upper and lower bases is d1, and the acute angle of each quadrilateral's projection onto the base is α1′. The Miura origami structure possesses a single degree of freedom, meaning it can be fully unfolded into a plane or fully folded into a plane. For example... Figure 3 As shown in (b), this application alters the characteristic of parallel arrangement of serrated creases in traditional Miura origami derivative structures, obtaining an arc-shaped Miura origami unit cell that can form an arc-shaped Miura origami derivative structure. This unit cell, which can be called an arc-shaped unit cell, still possesses a single degree of freedom. By connecting multiple arc-shaped unit cells in an array arrangement in rows and / or columns, a structure can be obtained... Figure 3 (c) shows the arc-shaped Miura origami derivative structure. In this case, the vertices of the folded three-dimensional structure are located on two parallel arc surfaces.

[0034] like Figure 3 As shown in (b), in a planar state, the arc-shaped unit cell of this application has three parallel straight creases 131 and a central serrated crease 133 and side serrated creases 132 arranged along the extension direction of the straight creases 131. The side serrated creases 132 are parallel to each other, and the central serrated crease 133 divides the arc-shaped unit cell into two supporting parts, namely the left and right parts in the figure. The two supporting parts are folded together at a predetermined angle. Please refer to... Figure 1 and Figure 2 In the folded state, each support part is supported at both ends by the first arc-shaped side plate 11 and the second arc-shaped side plate 12, respectively.

[0035] Please continue to refer to this. Figure 3(b), the basic geometric parameters of the arc-shaped unit cell in the planar state are l, a1, a2, and h, l is the length of the straight crease 131 on the side formed by the middle zigzag crease 133, and the two parts are equal in length, the straight creases 131 are parallel to each other and equal in length; h is the distance between adjacent straight creases 131, which are arranged at equal intervals; a1 is the acute angle formed by the middle straight crease 131 and the side of the zigzag crease 132, and a2 is the acute angle formed by the middle straight crease 131 and the side of the middle zigzag crease 133, the corresponding top angle (2a2) of the middle zigzag crease 133 and the corresponding top angle (2a1) of the side zigzag crease 132 are not equal, Figure 3 (b) shows that the corresponding top angle of the middle zigzag crease 133 is smaller than that of the side zigzag crease 132. The two sides of all zigzag creases are symmetrically located with respect to the middle straight crease 131, wherein the side length of the side of the side zigzag crease 132 is a1, and the side length of the side of the middle zigzag crease 133 is a2. In actual implementation, please refer to Figure 3 (c), since the two support parts of the arc-shaped unit cell are periodically arranged in the overall structure, the division of the arc-shaped unit cell can also be obtained by Figure 3 (b) is the structure obtained by transposing the left and right parts of (b), so that, Figure 3 (b) shows that the corresponding top angle of the middle zigzag crease 133 is smaller than that of the side zigzag crease 132. The two sides of all zigzag creases are symmetrically located with respect to the middle straight crease 131, wherein the side length of the side of the side zigzag crease 132 is a1, and the side length of the side of the middle zigzag crease 133 is a2. In actual implementation, please refer to

[0036] The arc-shaped unit cell of the present application is periodically arranged M and N times along the x-axis and y-axis directions, respectively, and after folding, a three-dimensional arc-shaped structure (M=3, N=1) as shown in Figure 3 (c) is obtained. The corresponding folding angle is As variables, the circumferential central angle of the arc-shaped unit cell along the y-axis is θ0, and the width is H. In the folded state, the vertex angle corresponding to the end of the edge sawtooth crease 132, the vertex angle formed by folding the edge sawtooth crease 132, the vertex angle corresponding to the end of the middle sawtooth crease 133, and the vertex angle formed by folding the middle sawtooth crease 133 are located on a cylindrical surface, and all the cylindrical surfaces are coaxial with the axis parallel to the y-axis. Among them, r1 is the radius of the cylindrical surface on which the vertex angle corresponding to the end of the edge sawtooth crease 132 is located; r2 is the radius of the cylindrical surface on which the vertex angle corresponding to the end of the middle sawtooth crease 133 is located; r3 is the radius of the cylindrical surface on which the vertex angle formed by folding the edge sawtooth crease 132 is located; r4 is the radius of the cylindrical surface on which the vertex angle formed by folding the middle sawtooth crease 133 is located. r2 is the shortest radius, i.e. the inner diameter of the arc-shaped Miura-origami-derived structure, and r3 is the longest radius, i.e. the outer diameter of the arc-shaped Miura-origami-derived structure. It should be noted that the various radii in the figure intersect at the same axis (the axis is parallel to the y-axis) rather than a point. By adjusting the proportion of the edge straight crease 131 divided by the middle sawtooth crease 133, the number of cylindrical surfaces can be reduced to two, and stable support can be obtained.

[0037] Optionally, the distance between the vertex angle corresponding to the end of the edge sawtooth crease 132, the vertex angle formed by folding the edge sawtooth crease 132, the vertex angle corresponding to the end of the middle sawtooth crease 133, and the vertex angle formed by folding the middle sawtooth crease 133 and the axis corresponding to the cylindrical surface, i.e. the radius of each cylindrical surface, satisfies the following relationship:

[0038] r3-r1-t1 / 2≤t2 / 2 (1)

[0039] r4-r2-t1 / 2≤t2 / 2 (2)

[0040] Where t1 is the thickness of the arc-shaped unit cell; t2 is the thickness of the first arc-shaped side plate 11 or the second arc-shaped side plate 12. Under this size relationship, the neutral layer at the vertex corresponding to r3 overlaps the neutral layer of the corresponding arc-shaped side plate, and can ensure that the outer vertex corresponding to r1 is higher than the inner surface of the corresponding arc-shaped side plate, thereby realizing the contact between each vertex of the arc-shaped unit cell and the corresponding arc-shaped side plate and obtaining stable support.

[0041] In designing the arc-shaped Miura-origami-derived structure that fits the target curved surface, the macroscopic geometric parameters r1, r2, r3, θ0, and H of the arc-shaped Miura-origami-derived structure are known geometric parameters, and the basic parameters l, α1, α2, h, and the folding angle of the arc-shaped unit cell can be obtained by geometric analysis.

[0042]

[0043]

[0044]

[0045]

[0046]

[0047]

[0048]

[0049]

[0050] wherein θ1, θ2 are the top angles of the isosceles triangle in which the adjacent straight creases lie, and m1, m2 are the heights of the isosceles triangle in which the adjacent zigzag creases lie.

[0051] The arc-shaped Miura origami derived structure has the same folding characteristics as the traditional Miura origami structure, and can be completely unfolded and completely folded. Since the arc-shaped Miura origami derived structure is a periodic array structure, the rotation angle between the arc-shaped unit cells is equivalent to the central angle θ0 of the arc-shaped unit cell, and the value of the rotation angle is determined by the folding degree of the arc-shaped Miura origami derived structure When the structure is completely folded, i.e. , the rotation angle reaches the maximum value; when , the structure is completely unfolded into a plane, and the rotation angle is 0.

[0052] Please continue to refer to Figure 1 and Figure 2 , the 3D model of the arc-shaped unit can be established by means of SolidWorks. As shown in Figure 3 (c), the design method of the arc-shaped Miura origami derived structure is taken as a reference, the model with M=5 and N=3 is taken as the intermediate plate layer 13, the first arc-shaped side plate 11 and the second arc-shaped side plate 12 are respectively the inner and outer tangent sector surfaces of the arc-shaped Miura origami derived structure, and the arc-shaped unit as shown in Figure 1 and Figure 2 is obtained. The central angle of the arc-shaped unit occupied by the two end points of the intermediate plate layer 13 to the axis is the central angle θ scale of the sector surface, and the radii of the two surfaces are r2 and r3 respectively. The plate thickness t1 of the intermediate plate layer 13 is 0.1mm, and the modeling parameters are: r1=40.96mm, r2=40mm, r3=41mm, θ0=2.38°, H=2mm. Under the parameters, the macroscopic size of the lower surface of the second arc-shaped side plate 12 along the radial and circumferential directions is about 6mm×10mm, the central angle θ scale is about 14.54°, and the total thickness T of the arc-shaped unit along the radial direction is 1mm (i.e. r3-r2).

[0053] Optionally, the first arc-shaped side plate 11, the second arc-shaped side plate 12 and the middle plate layer 13 are integrally formed, and the materials are the same, for example, 3D printing can be used to integrally form the GR high-precision hard resin.

[0054] Optionally, the arc-shaped Miura-ori derived structure forms at least one level of support structure between the first arc-shaped side plate 11 and the second arc-shaped side plate 12. In actual implementation, through the design of the crease of each support part, each support part can form at least one level of support structure, so that the ideal crushing mode can be obtained according to the protection requirements, and better protection effect can be achieved. Figures 1 to 3 In the middle, the sawtooth crease 133 corresponding to the middle part of the support part and the sawtooth crease 132 corresponding to the side part are not provided with a sawtooth crease to form a one-level support structure. As shown in Figure 4 (a) is a geometric diagram of the paper folding structure that can form a two-level support structure, and the sawtooth crease 134 corresponding to the middle part of the support part and the sawtooth crease 132 corresponding to the side part are provided with an even number of derived sawtooth creases 134 arranged along the extension direction of the straight crease to form at least two levels of support structure, and the number of derived sawtooth creases 134 is preferably 2. That is, in Figure 3 (b) shows that two support parts are respectively provided with Figure 4 The derived sawtooth crease 134 shown in (a) separates each support part into three segments to form a two-level support structure, and the included angle α between the edge of the derived sawtooth crease 134 and the straight crease of the middle part can be selected according to actual design.

[0055] Figure 3 (b) is a geometric diagram of an arc-shaped unit cell with a one-level support structure, Figure 4 (a) is a geometric diagram of a paper folding unit for forming a two-level support structure. By adjusting Figure 3 (b) The length of the side of the adjacent quadrilateral along the straight crease 131 (i.e. l) can realize Figure 4 (b) shows the height difference H' of the section where the two end sawtooth creases are located, wherein the sum of l1, l2 and l3 is l, and the values of l1, l2 and l3 are determined by the folding degree of the arc-shaped unit cell and the height difference of the two end sawtooth creases of the adjacent quadrilateral. By introducing the two-level support structure as shown in Figure 4 (a), a stable crushing mode can be induced in the deformation process of the arc-shaped unit with a thickness of H', and the development of the arc-shaped Miura-ori derived structure will not affect the foldable characteristics of the overall structure, so that it is suitable for various Miura-ori derived structures.

[0056] As shown in Figure 4 (b) and Figure 4(c) shown is the center line A-C-D-B of the fully folded arc-shaped unit cell with secondary support structure as a two-dimensional structure, wherein the line segment AB is the center line of the arc-shaped unit cell with primary support structure, and the line segment CD is perpendicular to the line segment AB. On this basis, the modeling parameters of the arc-shaped unit with primary support structure are taken as M = 5, r2 = 40.0 mm, r3 = 41.0 mm, the plate thickness t1 of the arc-shaped unit cell is 0.1 mm, the thickness T of the arc-shaped unit is 1 mm, the central angle θ of the arc-shaped unit is 14.3°, and the arc-shaped unit cell with secondary support structure is established as shown in scale (b). Figure 5 (a) shown is a single-layer two-dimensional arc-shaped unit with primary support structure. Further, the length of the line segment CD is taken as 0.3 mm, and the intersection points of the line segments are simplified into triangles, and the single-layer two-dimensional arc-shaped unit with secondary support structure is established as shown in Figure 5 (b). Figure 5 By testing the simplified models shown in Figure 5 (a) and (b), the crushing modes of the two can be compared. It can be understood that the geometric relationship of the arc-shaped unit cell with secondary support structure is basically the same as that of the arc-shaped unit cell with primary support structure, and the main changed parameter is l, so the parameter geometric relationship of the arc-shaped unit cell with secondary support structure is not described here.

[0057] The arc-shaped unit of the present application comprises a first arc-shaped side plate, a second arc-shaped side plate and an intermediate plate layer, the bending directions of the first arc-shaped side plate and the second arc-shaped side plate are the same, the intermediate plate layer has an arc-shaped Miura fold derived structure, and the arc-shaped Miura fold derived structure forms at least one level of support structure between the first arc-shaped side plate and the second arc-shaped side plate. The present application designs an arc-shaped unit capable of being used for arc-shaped object protection based on Miura fold, utilizes at least one level of support structure to form a reasonable crushing mode, can effectively disperse impact force in time, greatly improves the protection performance while retaining structural flexibility, has the characteristics of light weight, low peak value, long effective stroke, small fluctuation and the like, designs a secondary support structure, further optimizes the energy absorption characteristics of the arc-shaped unit, and reduces the peak load of the arc-shaped unit under medium and high speed impact.

[0058] Second embodiment

[0059] As shown in Figure 6 , Figure 7 and Figure 8 , the arc-shaped protection structure of the present embodiment comprises an arc-shaped flexible substrate 2 and a plurality of arc-shaped units 1, the arc-shaped units 1 are laid on at least one side surface of the arc-shaped flexible substrate 2, and are preferably laid on the convex side surface of the arc-shaped flexible substrate 2.

[0060] The structure of the arc unit 1 is as described in the first embodiment, wherein the intermediate plate layer 13 has an arc-shaped Mikura origami derived structure and forms at least one level of support structure, and the specific structure is described in the first embodiment, which will not be repeated here.

[0061] The arc units 1 are arranged periodically and staggered with each other. By referring to the arrangement form of fish scales, the center line of the rear row of arc units 1 is aligned with the gap of the front row of arc units 1, and there is an overlapping area and a relative rotation angle between the adjacent arc units 1 along the ring direction, so as to ensure that the upper and lower sections of the adjacent arc units 1 are completely fitted.

[0062] In some embodiments, the thickness of the optional arc-shaped flexible substrate 2 is 5 mm, the inner and outer radii are 35 mm and 40 mm respectively, and the width is 40 mm. The macroscopic size of the upper surface of the arc-shaped flexible substrate 2 along the radial and ring directions is about 40 mm x 60 mm, and the central angle is 86°. The arc units 1 are arranged along the ring direction of the arc-shaped flexible substrate 2 for 7 times along the radial direction for 6 times. By referring to the arrangement form of fish scales, each row of arc units 1 is arranged along the ring direction of the arc-shaped flexible substrate 2 with a regular interval of 6, 5, 6, 5, and so on, that is, the center line of the rear row of arc units 1 is aligned with the gap of the front row of arc units 1. The number of arc units 1 in one row is 5, and each side is filled with half an arc unit 1. The overlapping area between the adjacent arc units 1 along the ring direction is 1 / 4 of the ring length of a single arc unit 1, and the relative rotation angle is about 7.16° (the y-axis is the rotation axis) to ensure that the upper and lower sections of the adjacent arc units 1 are completely fitted. The proportional arc units 1 and the arc-shaped protective structure can be formed by means of additive manufacturing technology such as 3D printing. In actual implementation, the arc units 1 can be bonded on the surface of the arc-shaped flexible substrate 2 by means of a bonding agent such as silicone, and the arc-shaped flexible substrate 2 can be made of a flexible material such as PDMS. Since the upper and lower surfaces of the adjacent arc units 1 along the ring direction are completely fitted, there is no relative rotation angle, therefore, compared with the planar structure, the arc units 1 are more suitable for arc-shaped protective objects, can be more closely fitted to the arc-shaped surface, thereby avoiding the disadvantage that the planar structure may be pulled to the local flexible substrate under external force due to the relative rotation angle between the planar structures when the planar structure is attached to the arc-shaped surface, and further, the impact load can be more evenly dispersed by the surrounding arc units 1, thereby reducing the damage to the flexible object.

[0063] The arc-shaped protective structure of the present application comprises an arc-shaped flexible substrate and a plurality of arc units as described in the first embodiment, and the arc units are laid on at least one side surface of the arc-shaped flexible substrate. The present application designs arc units and arc-shaped protective structures that can be used for the protection of arc-shaped objects based on Mikura origami, and utilizes at least one level of support structure to form a reasonable crushing mode, which can effectively disperse the impact force in time, while maintaining the flexibility of the structure and greatly improving the protection performance.

[0064] The above embodiments are only illustrative of the principles of the present application and its effects, and are not intended to limit the present application. Any modification or change made by any person skilled in the art without departing from the spirit and scope of the present application shall be covered by the claims of the present application.

Claims

1. An arc-shaped unit, characterized in that, The device includes a first arc-shaped side plate, a second arc-shaped side plate, and a middle plate layer. The first arc-shaped side plate, the second arc-shaped side plate, and the middle plate layer are integrally formed. The first arc-shaped side plate and the second arc-shaped side plate have the same bending direction. The middle plate layer has an arc-shaped Miura origami-derived structure. The arc-shaped Miura origami-derived structure forms at least one level of support structure between the first arc-shaped side plate and the second arc-shaped side plate. The arc-shaped Miura origami-derived structure includes multiple arc-shaped unit cells arranged in an array. Each arc-shaped unit cell has two support parts that can be folded together. In the folded state, each of the supporting parts forms at least one level of supporting structure and is supported at both ends by the first arc-shaped side plate and the second arc-shaped side plate, respectively. In the planar state, the arc-shaped unit cell has parallel straight creases and central serrated creases and side serrated creases arranged along the extension direction of the straight creases. The central serrated crease divides the arc-shaped unit cell into two supporting parts. The apex angles corresponding to the central serrated crease and the side serrated crease are not equal. In the folded state, the apex angles corresponding to the ends of the side serrated creases, the apex angles formed by folding the side serrated creases, the apex angles corresponding to the ends of the middle serrated creases, and the apex angles formed by folding the middle serrated creases are each located on a cylindrical surface. All the cylindrical surfaces are coaxial, and the distance between each apex angle and the axis corresponding to its cylindrical surface satisfies the following relationship: r 3 -r 1 -t 1 / 2≤t 2 / 2 ； r 4 -r 2 -t 1 / 2≤t 2 / 2 ； in, r 1 is the radius of the cylindrical surface where the apex angle of the end corresponding to the serrated crease on the side is located; r 2 is the radius of the cylindrical surface where the apex angle of the end corresponding to the central sawtooth crease is located; r 3 is the radius of the cylindrical surface containing the apex angle formed by the folding of the side sawtooth crease; r 4 is the radius of the cylindrical surface where the apex angle formed by the folding of the central serrated crease is located; t 1 represents the plate thickness of the arc-shaped unit cell; t 2 represents the thickness of either the first or the second arc-shaped side plate.

2. The arc-shaped unit according to claim 1, characterized in that, The straight creases are of equal length and are spaced at equal intervals. The two parts of the straight crease located on the side, which are divided by the central serrated crease, are of equal length.

3. The arc-shaped unit according to claim 1, characterized in that, The supporting portion has no serrated creases between the central serrated crease and the side serrated creases to form a primary support structure, or has an even number of derivative serrated creases arranged along the extension direction of the straight crease to form at least a two-level support structure; the two sides of all serrated creases are symmetrical to the straight crease located in the middle.

4. An arc-shaped protective structure, characterized in that, It includes an arc-shaped flexible substrate and a plurality of arc-shaped units as described in any one of claims 1-3, wherein the arc-shaped units are laid on at least one side surface of the arc-shaped flexible substrate.

5. The arc-shaped protective structure according to claim 4, characterized in that, The arc-shaped units are arranged periodically and overlap each other.

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