Double-layer planar film tensioning system

Abstract

The invention discloses a double-layer planar film tensioning system, and belongs to the field of film tensioning, the double-layer planar film tensioning system comprises two planar films which are parallel to each other and are arranged in a spaced and aligned manner in the thickness direction, the two planar films are synchronously tensioned in the left-right direction through a left-right tensioning assembly, and the two planar films are synchronously tensioned in the front-back direction through a front-back tensioning assembly; therefore, the alignment precision of the double-layer planar film is ensured; in addition, the plane precision of the double-layer plane film is achieved through the arrangement of a constant tension spring, and the interlayer spacing precision of the double-layer plane film is achieved through the arrangement of a pulley block.

Description

Technical Field

[0001] This invention relates to the field of thin film tensioning technology, and in particular to a double-layer planar thin film tensioning system. Background Technology

[0002] With the continuous development of aerospace technology, the demand for large-area antennas is constantly increasing. Traditional phased array antenna design and manufacturing processes cannot meet the performance and cost targets of future space synthetic aperture radar (SAR). One way to significantly reduce the weight, volume, and associated costs of SAR is to replace traditional rigid antenna structures with flexible thin films.

[0003] Besides antenna structures, the demand for large-area, low-mass, and high-encapsulation-efficiency thin-film structures is also increasing in spacecraft structures such as sunshades, solar sails, and flexible solar cells. To achieve more functions in spacecraft, the demand for multilayer thin-film structures is also growing, demonstrating high practical value and promising application prospects.

[0004] However, as a flexible cable-membrane structure system, the thin film material itself has no ability to resist bending and pressure, and its shear strength is also very low. Many factors such as inappropriate tension may affect the flatness of the film surface, which in turn affects the working performance of electronic components on the thin film, thus causing the antenna to fail to perform its expected function. Therefore, thin film antenna structures have high requirements for the flatness of the thin film.

[0005] For multilayer thin film structures, in order to ensure the coordination between the layers and that the structure functions correctly according to the design orientation, not only is high flatness required for each layer, but also high alignment and interlayer spacing accuracy is required between different layers. However, in existing technologies, it is difficult to guarantee alignment and interlayer spacing accuracy during the tensioning of multilayer thin film structures. Summary of the Invention

[0006] To address the problem of difficulty in ensuring alignment accuracy and interlayer spacing accuracy during the tensioning of large-scale multilayer thin film structures in existing technologies, the present invention aims to provide a double-layer planar thin film tensioning system to at least partially solve the above-mentioned problems.

[0007] To achieve the above objectives, the technical solution of the present invention is as follows:

[0008] A double-layer planar thin film tensioning system, comprising:

[0009] Two planar films, which are parallel to each other and aligned at intervals along the vertical direction;

[0010] A base on which left and right tensioning components and front and rear tensioning components are mounted;

[0011] The left and right tensioning components are used to simultaneously tension the two planar films in the left and right directions, and the front and rear tensioning components are used to simultaneously tension the two planar films in the front and rear directions.

[0012] Wherein, the up-down direction is the direction perpendicular to the thickness of the planar thin film (2), and the left-right direction is perpendicular to the front-back direction and is also perpendicular to the up-down direction.

[0013] In some preferred embodiments, the left and right tensioning assembly includes four left and right tensioning structures, with each pair of left and right tensioning structures forming a group and used to tension the planar film from the left and right sides; each left and right tensioning structure includes left and right tension springs, left and right cross cables, and left and right tensioning pulleys; there are two left and right tension springs, which are respectively arranged at the front and rear ends of the left or right side of the planar film; the left and right cross cables are passed through left and right cross cable sleeves provided on the left and right side edges of the planar film; the two ends of the left and right cross cables pass through the left and right cross cable sleeves and are respectively connected to the two left and right tension springs; the left and right tensioning pulleys are used to change the direction of the left and right cross cables, so that the two ends of the left and right cross cables can turn to the corresponding left and right tension springs after passing through the left and right cross cable sleeves;

[0014] The front and rear tensioning assembly includes two front and rear tensioning structures, which are respectively arranged on the front and rear sides of the planar film. Each front and rear tensioning structure includes front and rear tension springs, a splitter, front and rear cross cables, and front and rear tensioning pulleys. There are two front and rear tension springs, respectively arranged at the left and right ends of the front or rear side of the planar film. Each of the two front and rear tension springs is equipped with a splitter, the resultant joint of which is connected to the front and rear tension springs. The two component joints of the splitter are distributed along the vertical direction and are located within the plane of the two planar films. There are two front and rear cross cables, respectively passing through front and rear cross cable sleeves located at the front and rear edges of the two planar films. Both ends of the front and rear cross cables exit from the cross cable sleeves and are respectively connected to the component joints located in the same plane. The front and rear tensioning pulleys are used to change the direction of the front and rear cross cables, allowing the two ends of the front and rear cross cables to turn towards the corresponding component joints after exiting the cross cable sleeves.

[0015] In some preferred embodiments, the left and right sides of the planar film have two or more spans, and the left and right span cables have notches at the spans, and there are corresponding steering pulleys at the notches, so that the left and right span cables can be turned by the steering pulleys.

[0016] In some preferred embodiments, the planar thin film has three spans on both its left and right edges.

[0017] In some preferred embodiments, the front and rear tensioning fixed pulleys, the left and right tensioning fixed pulleys, and the steering fixed pulleys are all rotatably connected in pairs at intervals to mounting rods arranged along the thickness direction of the planar film, and the installation spacing is the same as the spacing between the two planar films; wherein, the mounting rods are all fixedly connected to the base.

[0018] In some preferred embodiments, both the left and right tensioning structures and the front and rear tensioning structures include turnbuckles, and the turnbuckles are connected between the left and right span cables and the left and right tensioning springs. The turnbuckles are also connected between the combined force connector of the splitter and the front and rear tensioning springs.

[0019] In some preferred embodiments, both the left and right tensioning structures and the front and rear tensioning structures include a two-in-one splitter. The two-in-one splitter is connected between the left and right tensioning springs and the turnbuckle, and between the front and rear tensioning springs and the turnbuckle. The resultant joint of the two-in-one splitter is connected to the turnbuckle. Both the left and right tensioning springs and the front and rear tensioning springs are connected to two pull ropes A, and the two pull ropes A are respectively connected to the two force-distributing joints of the two-in-one splitter.

[0020] In some preferred embodiments, the one-to-two splitter is trapezoidal and perpendicular to the planar film, and the two-in-one splitter is rectangular and parallel to the planar film.

[0021] In some preferred embodiments, the left and right span cables and the front and rear span cables are all Kevlar cables.

[0022] In some preferred embodiments, the left and right tension springs and the front and rear tension springs are all constant tension springs.

[0023] The beneficial effects of the present invention by adopting the above technical solution are as follows: the present invention enables two planar films to be tensioned synchronously in the left and right directions and the front and back directions by setting the left and right tensioning components and the front and back tensioning components, and by limiting the interlayer position between the two planar films by the pulley, thereby ensuring the planar accuracy, alignment accuracy and interlayer spacing accuracy of the double-layer planar film during the tensioning process. Attached Figure Description

[0024] Figure 1 This is a top view of the present invention;

[0025] Figure 2 This is a side view of the present invention;

[0026] Figure 3 This is a side view of the splitter in this invention;

[0027] Figure 4This is a top view of the two-in-one splitter in this invention;

[0028] Figure 5 for Figure 1 Enlarged view of a portion of point A in the middle;

[0029] Figure 6 for Figure 1 Enlarged view of a section at point B in the middle;

[0030] In the diagram: 1-base, 2-planar membrane, 21-left and right spanning cable sleeves, 22-front and rear spanning cable sleeves, 23-notch, 23-steering pulley, 3-left and right tension springs, 4-left and right spanning cables, 5-left and right tensioning pulleys, 6-box A, 7-front and rear tension springs, 8-one-to-two cable splitter, 9-front and rear spanning cables, 10-front and rear tensioning pulleys, 11-box B, 12-turnbuckle, 13-two-in-one cable splitter, 14-pull rope A, 15-pull rope B, 16-pull rope C. Detailed Implementation

[0031] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings. It should be noted that these descriptions are for the purpose of aiding understanding the present invention, but do not constitute a limitation thereof. Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0032] It should be noted that in the description of this invention, the terms "upper", "lower", "left", "right", "front", "rear", etc., indicate the orientation or positional relationship based on the description of the structure of this invention shown in the accompanying drawings. They are only for the convenience of describing this invention and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0033] The terms "first" and "second" in this technical solution are merely designations for corresponding structures that are identical or similar, or that perform similar functions. They do not represent an arrangement of the importance of these structures, nor do they imply any ranking, comparison of size, or other meaning.

[0034] Furthermore, unless otherwise explicitly specified and limited, the terms "installation" and "connection" should be interpreted broadly. For example, a connection can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two structures. Those skilled in the art can understand the specific meaning of the above terms in this invention by considering the overall concept of the invention and the specific context of the solution.

[0035] Example

[0036] A double-layer planar thin film tensioning system, as shown in Figures 1-2, includes a base 1, two planar thin films 2, and left and right tensioning components and front and rear tensioning components.

[0037] The base 1 is used as the mounting base for the left and right tensioning components and the front and rear tensioning components. It is generally in the form of a planar plate or frame. For example, the base 1 can adopt a U-shaped cross section and can be made of 7075 aluminum alloy or carbon fiber.

[0038] Two planar films 2 are laid flat on top of the base 1, and the two planar films 2 are parallel to each other. They are also spaced apart and aligned along the thickness direction (i.e., the vertical direction). The planar films 2 are planar films with three spans on each side and one span on each front and back edge, such as... Figure 1 As shown.

[0039] The left and right tensioning components are used to simultaneously tension two planar films 2 in the left and right directions, and the front and rear tensioning components are used to simultaneously tension two planar films 2 in the front and rear directions. The left and right directions are perpendicular to each other and both are perpendicular to the thickness direction of the planar films 2.

[0040] In this embodiment, the left and right tensioning assembly includes four left and right tensioning structures, with each pair of left and right tensioning structures forming a group. The two planar films 2 correspond to two groups respectively, and the two left and right tensioning structures in each group are used to tighten the planar film 2 from the left and right sides respectively.

[0041] The left and right tensioning structures include left and right tensioning springs 3, left and right spanning cables 4, and left and right tensioning fixed pulleys 5. The structures and principles of the four left and right tensioning structures are the same. This embodiment takes the left and right tensioning structure at the left side of the planar film 2 as an example for explanation.

[0042] There are two left and right tension springs 3, which are respectively arranged at the front and rear ends of the left side of the planar membrane 2. There is one left and right span cable 4, which passes through the left and right span cable sleeve 21 set on the left edge of the planar membrane 2, and both ends of the left and right span cable 4 pass through the left and right span cable sleeve 21. Then, the two ends of the left and right span cable 4 are respectively connected to the two left and right tension springs 3. There are two left and right tension fixed pulleys 5, which are rotatably connected to the mounting rod. The mounting rod is fixed to the base 1 in a direction perpendicular to the planar membrane 2 (i.e., the up and down direction). The left and right tension fixed pulleys 5 are used to change the direction of the two ends of the left and right span cables 4, so that the two ends of the left and right span cables 4 can turn to the corresponding left and right tension springs 3 after passing through the left and right span cable sleeve 21.

[0043] It is easy to understand that since the two planar membranes 2 are arranged vertically aligned, the two left and right tensioning structures on the left side of the two planar membranes 2 are also usually arranged vertically aligned. Accordingly, two left and right tensioning fixed pulleys 5 are rotatably connected to each mounting rod, and the distance between the two left and right tensioning fixed pulleys 5 is equal to the distance between the two planar membranes 2. Similarly, the two vertically aligned left and right tensioning springs 3 can be bolted to the same housing A6, which is then bolted to the base 1. The housing A6 has corresponding through holes for external interaction, so that the elastic force of the left and right tensioning springs 3 can be transmitted to the left and right spanning cables 4 through the through holes.

[0044] like Figure 1 As shown, the planar film 2 has three spans on its left and right sides. To tighten the planar film 2 in the left and right direction using two left and right span cables 4, it is also necessary to provide a lateral force away from the planar film 2 at the span positions. Therefore, in this embodiment, the left and right span cable sleeves 21 have notches 23 at the span positions, allowing the left and right span cables 4 to be exposed through the notches 23. At the same time, a steering pulley 24 is provided corresponding to the notch 23, and the left and right span cables 4 pass around the outside of the steering pulley 24, thereby providing a lateral force to the left and right span cables 4 at the span positions through the steering pulley 24, so that the left and right span cables 4 perfectly match the three-span shape of the left and right sides of the planar film 2. It is easy to understand that the attached... Figure 4 This is only a schematic diagram of the planar thin film 2; in actual applications, the number and position of spans are not limited.

[0045] Similarly, since the two planar films 2 are arranged vertically aligned, the steering pulleys 24 are also arranged vertically in pairs on the left side of the two planar films 2 (at each span position). The two vertically aligned steering pulleys 24 can be connected to the same mounting rod, and the distance between the two vertically aligned steering pulleys 24 is equal to the distance between the two planar films 2.

[0046] Understandably, when the planar film 2 has more than two layers, it is only necessary to increase the number of left and right tensioning structures so that each layer of planar film 2 is tensioned from left to right by two left and right tensioning structures. Correspondingly, more left and right tensioning fixed pulleys 5 and more directional fixed pulleys 24 aligned vertically can be fixed to the mounting rod respectively.

[0047] In this embodiment, the front and rear tensioning assembly includes two front and rear tensioning structures, which are respectively arranged on the front and rear sides of the planar film 2. One of the front and rear tensioning structures is used to simultaneously tension the two planar films 2 from the front side, and the other front and rear tensioning structure is used to simultaneously tension the two planar films 2 from the rear side.

[0048] The front and rear tensioning structure includes front and rear tensioning springs 7, a splitter 8, front and rear cross cables 9, and front and rear tensioning pulleys 10. The two front and rear tensioning structures have the same structure and principle. The front and rear tensioning structure at the front side of the planar membrane 2 will be described in detail as an example.

[0049] There are two front and rear tension springs 7, which are respectively arranged on the left and right ends of the front side of the planar diaphragm 2.

[0050] There are two splitter units 8, one for each of the two front and rear tension springs 7. The splitter units 8 are roughly trapezoidal in shape and arranged in a plane perpendicular to the planar membrane 2, meaning they are arranged vertically. Specifically, each splitter unit 8 has one resultant joint and two component joints. Along the direction perpendicular to the planar membrane 2, the distance between the two component joints is the same as the distance between the two planar membranes 2. The other two component joints are equidistant from the resultant joint and are each half the distance between the two planar membranes 2. Figure 3 As shown. In the arrangement, the two force-splitting joints of the splitter 8 are located in the planes of the two planar films 2, respectively.

[0051] There are two front and rear spanning cables 9, and the two front and rear spanning cables 9 are respectively threaded through the front and rear spanning cable sleeves 22 set on the front and rear edges (in this case, the front edge) of the two planar membranes 2. Both ends of each front and rear spanning cable 9 pass through the corresponding front and rear spanning cable sleeves 22 and are then connected to two force-sharing joints (these two force-sharing joints belong to two one-to-two splitters 8) located in the same plane. The resultant force-sharing joints of the two one-to-two splitters 8 are then connected to two front and rear tension springs 7 respectively.

[0052] The front and rear tensioning fixed pulleys 10 are rotatably connected to another mounting rod, which is also fixed to the base 1 in a direction perpendicular to the plane film 2 (i.e., the up and down direction). There are four front and rear tensioning fixed pulleys 10, which are used to change the direction of the four ends of the two front and rear span cables 9 (after passing through the front and rear span cable sleeves 22), so that the two ends of each front and rear span cable 9 can turn to the resultant joint of the corresponding one-to-two splitter 8 after passing through the front and rear span cable sleeves 22.

[0053] It is also easy to understand that since the two planar membranes 2 are arranged vertically aligned, the two front and rear tension cables 9 on the front side of the two planar membranes 2 are also vertically aligned. Therefore, every two vertically aligned front and rear tension pulleys 10 can be connected to the same mounting rod, and the distance between the two front and rear tension pulleys 10 on the same mounting rod is equal to the distance between the two planar membranes 2. In this embodiment, the two front and rear tension springs 7 in the front and rear tensioning structure are respectively installed in the two housings B11 by bolts. The housings B11 are fixed to the base 1 by bolts. The housings B11 also have corresponding through holes for interaction with the outside, so that the elastic force of the front and rear tension springs 7 can be transmitted outward through the through holes.

[0054] Understandably, when the planar membrane 2 has more than two layers, it is only necessary to replace the one-to-two splitter 8 with a one-to-N splitter, where N equals the number of layers of the planar membrane 2, and ensure that each force-sharing joint corresponds to the plane of each layer of the planar membrane 2. Correspondingly, a larger number of front and rear tensioning pulleys 10, aligned vertically, can be fixed to the mounting rod.

[0055] In some embodiments, each left-right tensioning structure and each front-rear tensioning structure includes a turnbuckle 12, such as Figure 1 As shown.

[0056] In the left and right tensioning structure, turnbuckles 12 are connected between the left and right span cables 4 and the left and right tension springs 3. In the front and rear tensioning structure, turnbuckles 12 are also connected between the resultant joint of the splitter 8 and the front and rear tension springs 7. That is, the resultant joint of the splitter 8 is connected to the turnbuckles 12 through the cable C16. Figure 3 As shown. With this setup, the tightness can be adjusted using the turnbuckle 12.

[0057] In some embodiments, each left and right tensioning structure and each front and rear tensioning structure includes a two-in-one splitter 13.

[0058] In the left and right tensioning structures, a two-in-one splitter 13 connects both the left and right tensioning springs 3 and the turnbuckles 12. The two-in-one splitter 13 has a rectangular structure and is located within the plane of the corresponding planar membrane 2. The two-in-one splitter 13 also has one resultant joint and two component joints, which are distributed in an isosceles triangle shape. The resultant joint occupies the vertex of the isosceles triangle. Figure 4 As shown. The left and right tension springs 3 are connected to two pull ropes A14. The two pull ropes A14 are parallel to each other and are respectively connected to the two force-sharing joints of the two-in-one splitter 13. The force-combining joint of the two-in-one splitter 13 is connected to the turnbuckle 12 via pull rope B15, as shown. Figure 5 As shown.

[0059] In the front and rear tensioning structure, each front and rear tensioning spring 7 is also connected to a two-in-one splitter 13 between itself and the corresponding turnbuckle 12. This two-in-one splitter 13 is the same as the two-in-one splitter 13 in the left and right tensioning structures, and will not be described again. The front and rear tensioning springs 7 are also connected to two pull ropes A14. These two pull ropes A14 are parallel to each other and are respectively connected to the two force-sharing joints of the two-in-one splitter 13. The force-combining joint of the two-in-one splitter 13 is connected to the turnbuckle 12 through pull rope B15, as shown below. Figure 6 As shown.

[0060] However, if the turnbuckle 13 is not included, a two-in-one splitter 13 can be installed separately. In the left and right tensioning structure, the two-in-one splitter 13 is connected between the left and right tension springs 3 and the left and right span cables 4. The left and right tension springs 3 are connected to two pull ropes A14, which are parallel to each other and are respectively connected to the two force-sharing joints of the two-in-one splitter 13. The resultant joint of the two-in-one splitter 13 is connected to the left and right span cables 4. In the front and rear tensioning structure, the front and rear tension springs 7 are each connected to the corresponding one-to-two splitter 8, and the front and rear tension springs 7 are also connected to two pull ropes A14, which are parallel to each other and are respectively connected to the two force-sharing joints of the two-in-one splitter 13. The resultant joint of the two-in-one splitter 13 is connected to the resultant joint of the one-to-two splitter 8 through pull rope B15.

[0061] In this embodiment, the left and right tension springs 3 and the front and rear tension springs 7 are all constant tension springs. The left and right span cables 4 and the front and rear span cables 9 are all made of lightweight, high-strength materials such as Kevlar. The one-to-two splitter 8 and the two-in-one splitter 13 can both be made of aluminum alloy or lightweight polymer composite materials, thereby ensuring rigidity while ensuring that the splitter will not deform significantly under tension, which is beneficial to ensuring the alignment accuracy and interlayer distance accuracy between the double-layer planar thin film 2. Similarly, the mounting rod can also be made of the same material to ensure rigidity and avoid significant deflection under tension, which is beneficial to ensuring the alignment accuracy and interlayer distance accuracy between the double-layer planar thin film 2.

[0062] It is understandable that there can be multiple double-layer planar film systems including two planar films 2. They can be installed side by side on the same base 1, for example, side by side in the left and right direction. At this time, the left and right tension springs 3 and the front and rear tension springs 7 of the adjacent double-layer planar film systems are close to each other. Therefore, these close springs can be installed in the same box, thereby saving the number of boxes used.

[0063] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and these variations still fall within the protection scope of the present invention.

Claims

1. A double-layer planar thin film tensioning system, characterized in that, include: Two planar films (2) are arranged parallel to each other and spaced apart in the vertical direction; A base (1) is provided, on which left and right tensioning components and front and rear tensioning components are installed; The left and right tensioning components are used to simultaneously tension the two planar films (2) in the left and right directions, and the front and rear tensioning components are used to simultaneously tension the two planar films (2) in the front and rear directions. Wherein, the up-down direction is the direction perpendicular to the thickness of the planar thin film (2), and the left-right direction is perpendicular to the front-back direction and is also perpendicular to the up-down direction.

2. The double-layer planar thin film tensioning system according to claim 1, characterized in that: The left and right tensioning assembly includes four left and right tensioning structures, with each pair of left and right tensioning structures forming a group and used to tighten the planar film (2) from the left and right sides; the left and right tensioning structure includes left and right tensioning springs (3), left and right cross cables (4), and left and right tensioning pulleys (5); there are two left and right tensioning springs (3) and they are respectively arranged at the front and rear ends of the left or right side of the planar film (2); the left and right cross cables (4) are inserted into the left and right cross cable sleeves (21) set on the left and right side edges of the planar film (2); the two ends of the left and right cross cables (4) pass through the left and right cross cable sleeves (21) and are respectively connected to the two left and right tensioning springs (3); the left and right tensioning pulleys (5) are used to change the direction of the left and right cross cables (4) so ​​that the two ends of the left and right cross cables (4) can turn to the corresponding left and right tensioning springs (3) after passing through the left and right cross cable sleeves (21); The front and rear tensioning assembly includes two front and rear tensioning structures, which are respectively arranged on the front and rear sides of the planar film (2); the front and rear tensioning structures include front and rear tension springs (7), a splitter (8), front and rear cross cables (9), and front and rear tensioning pulleys (10); there are two front and rear tension springs (7), which are respectively arranged on the left and right ends of the front or rear side of the planar film (2); each of the two front and rear tension springs (7) is equipped with a splitter (8), and the resultant joint of the splitter (8) is connected to the front and rear tension springs (7), and the two ends of the splitter (8) are connected to each other. The force-shaping joints are distributed along the vertical direction and are located in the plane of the two planar films (2); there are two front and rear span cables (9) and they are respectively inserted into the front and rear span cable sleeves (22) set on the front and rear sides of the two planar films (2). Both ends of the front and rear span cables (9) pass through the front and rear span cable sleeves (22) and are respectively connected to the force-shaping joints in the same plane; the front and rear tensioning pulleys (10) are used to change the direction of the front and rear span cables (9) so that the two ends of the front and rear span cables (9) can turn to the corresponding force-shaping joints after passing through the front and rear span cable sleeves (22).

3. The double-layer planar thin film tensioning system according to claim 2, characterized in that: The planar film (2) has two or more spans on its left and right sides. The left and right span cable sleeves (21) have notches (23) at the spans, and there is a steering pulley (24) at the notches (23) so that the left and right span cables (4) can be turned by the steering pulley (24).

4. The double-layer planar thin film tensioning system according to claim 3, characterized in that: The planar thin film (2) has three spans on both its left and right edges.

5. The double-layer planar thin film tensioning system according to claim 3 or 4, characterized in that: The front and rear tensioning fixed pulleys (10), the left and right tensioning fixed pulleys (5) and the steering fixed pulleys (24) are all rotatably connected in pairs to the mounting rods arranged along the thickness direction of the planar film, and the installation spacing is the same as the spacing between the two planar films (2); wherein, the mounting rods are all fixedly connected to the base (1).

6. The double-layer planar thin film tensioning system according to claim 2, characterized in that: The left and right tensioning structures and the front and rear tensioning structures both include turnbuckles (12). The left and right span cables (4) and the left and right tensioning springs (3) are both connected by turnbuckles (12). The combined force joint of the splitter (8) and the front and rear tensioning springs (7) are both connected by turnbuckles (12).

7. The double-layer planar thin film tensioning system according to claim 6, characterized in that: Both the left and right tensioning structures and the front and rear tensioning structures include a two-in-one splitter (13). The two-in-one splitter (13) is connected between the left and right tensioning springs (3) and the turnbuckle (12), and between the front and rear tensioning springs (7) and the turnbuckle (12). The combined force joint of the two-in-one splitter (13) is connected to the turnbuckle (12). The left and right tensioning springs (3) and the front and rear tensioning springs (7) are each connected to two pull ropes A (14). The two pull ropes A (14) are respectively connected to the two force joints of the two-in-one splitter (13).

8. The double-layer planar thin film tensioning system according to claim 2, characterized in that: The one-to-two splitter (8) is trapezoidal and perpendicular to the planar thin film (2), and the two-in-one splitter (13) is rectangular and parallel to the planar thin film (2).

9. The double-layer planar thin film tensioning system according to claim 2, characterized in that: The left and right span cables (4) and the front and rear span cables (9) are all Kevlar cables.

10. The double-layer planar thin film tensioning system according to claim 2, characterized in that: The left and right tension springs (3) and the front and rear tension springs (7) are all constant tension springs.

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