A planar membrane and its profile maintaining system for a deployable thin film antenna

Abstract

The application discloses a planar film for a deployable thin film antenna and a profile maintaining system thereof, the planar film is spliced by four or more modularized blocks, and the splicing seams between the blocks are not cross seams; the profile maintaining system comprises high-precision tension adjusting devices, rope tube patch groups and tension cables; a plurality of rope tube patches form an arc-shaped rope path, one end of the tension cable extends out of one end of the arc-shaped rope path and is connected with a corresponding high-precision tension adjusting device on the same side, the other end of the tension cable extends out of the other end of the arc-shaped rope path and is connected with another corresponding high-precision tension adjusting device on the same side, the tension of the tension cable is adjusted by adjusting the high-precision tension adjusting devices at the two ends of each tension cable, the planar film is stretched flat and the flat profile is maintained; the application can not only avoid tearing of the film, but also realize high-precision flatness of millimeter level for a planar film structure of hundreds of meters.

Description

Technical Field

[0001] This invention belongs to the field of antenna technology, specifically relating to a planar thin film for deployable thin-film antennas and its shape maintenance system. Background Technology

[0002] Traditional planar rigid antennas for spacecraft are generally rigid structures. With the increasing demand for large-aperture (hundreds of square meters or even larger) antennas for spacecraft, rigid antennas can no longer meet the requirements of launch due to their excessively large transmission volume and weight. Therefore, deployable thin-film antennas have received great attention due to their advantages such as lightweight and high packing ratio, and have become one of the current research hotspots for spacecraft. However, planar thin films are very large and need to be spliced ​​together from multiple pieces, and the splicing seams cannot have cross-shaped seams.

[0003] Regarding the shape maintenance system for planar thin films, in 2000, John KHLin et al. from ILC Dover in the United States designed a corner point shape maintenance system. This system involves creating reinforcing edges at the film's edge and directly tensioning the film's corners to apply tensile stress. However, this tensioning method causes numerous wrinkles on the film surface along the diagonal direction. In 2008, the German Aerospace Center (DLR) fabricated a 6m × 1.3m thin film prototype. Its shape maintenance system was designed with pipe tensioning. The film edge was cut into curved cable loops, and ropes were threaded through these loops. The ends of the ropes extending from the loops were tightened and fixed to a rectangular support frame. However, this cable loop design has relatively weak strength, and the tensioning direction of the ropes easily causes the cable loops to tear. Furthermore, the friction between the cable loops and the ropes is relatively high, resulting in a decrease in the uniformity of stress distribution within the film. Summary of the Invention

[0004] In view of this, the present invention provides a planar thin film for deployable thin film antennas and a shape maintenance system thereof. The deployable planar thin film antenna is a large-scale, lightweight, and high-precision deployable thin film antenna that can meet the large-aperture requirements of spacecraft. The shape maintenance system can apply uniform tensile stress to the thin film array of the deployable planar thin film antenna and realize a flexible connection between the thin film array and the support frame. It can not only avoid tearing of the thin film, but also achieve millimeter-level high-precision flatness of the planar thin film structure on the order of hundreds of meters.

[0005] This invention is achieved through the following technical solution:

[0006] A planar thin film for deployable thin film antenna, wherein the deployed planar thin film consists of a rectangular structure and two or more protruding corners provided on each short side of the rectangular structure and two or more protruding corners provided on each long side of the rectangular structure. Each corner has a corresponding corner point, and adjacent corner points are transitioned by concave arc edges; and the two short sides of the planar thin film are symmetrical to each other, and the two long sides are symmetrical to each other.

[0007] The planar film is composed of four or more modular segments spliced ​​together, and the splicing seams between the segments are not cross seams.

[0008] Furthermore, let the total number of corners set on the short side of the planar thin film be n1, and the total number of corners set on the long side be n2;

[0009] When n1 = 4, and the planar film is spliced ​​from six modular blocks, the six modular blocks are block A, block B, block C, block D, block E and block F. The number of blocks A and B is n1 = 4, the number of blocks C is two, the number of blocks D is several, the number of blocks E is four, and the number of blocks F is n2 - the number of blocks E, that is, n2 - 4.

[0010] Where block D is a rectangle;

[0011] Block F has a triangular structure, with the three sides of the triangle being a straight side I and two concave arc-shaped sides I.

[0012] Block E is a planar quadrilateral structure. The four sides of the planar quadrilateral structure are a long straight side, a short straight side, a concave arc side II, and a concave arc side III. One end of the short straight side is perpendicularly connected to the long straight side, and the other end of the short straight side is connected to the concave arc side III. The concave arc side II and the concave arc side III are adjacent.

[0013] A rectangular block formed by sequentially connecting several segments D constitutes the rectangular structure of the planar thin film. Segments E and F are both connected to the long side of the rectangular block. n2-4 segments F are divided into two groups and connected to the middle of the two long sides of the rectangular block respectively. The four segments E are connected one-to-one to the two ends of the two long sides of the rectangular block. The straight edge I of each segment F is connected to the long side of the rectangular block. The arc edges I on two adjacent segments F are joined to form a smooth arc edge. The long straight edge of each segment E is connected to the long side of the rectangular block, and the short straight edge is on the same straight line as the short side of the rectangular block. The arc edge II is joined to the arc edge I of segment F to form a smooth arc edge.

[0014] Block A has a triangular structure with three sides: a concave arc side IV, a concave arc side V, and a straight side II. Block B has a trapezoidal structure with two legs I: a concave arc side VI and a concave arc side VII. The length of the upper base I of the trapezoidal structure is the same as the length of the straight side II of block A. The straight side of block A connects with the upper base I of block B to form the corner of the short side of the planar film. The arc side IV of block A and the arc side VI of block B are smoothly joined together. The arc side V of block A and the arc side VII of block B are smoothly joined together to form the arc side IX.

[0015] Block C is a trapezoidal structure. The length of the lower base II of the trapezoidal structure is the sum of the lengths of the short straight sides of the two blocks E and the length of the long side of block D. Both sides of the trapezoidal structure are concave arc-shaped sides VIII.

[0016] The middle of the lower base II of each segment C is connected to the short side of the corresponding rectangular block, and the two ends are connected to the short straight sides of the two corresponding segments E respectively; the two ends of the upper base II of each segment C are respectively connected to the lower base I of segment B, and the arc edges IX at both ends are set opposite to each other; the middle of the upper base II of each segment C is provided with an inward arc edge X, and the inward arc edge X and the arc edges IX at both ends are respectively connected to form a smooth arc edge; one end of the arc edge VIII of each segment C is connected to the arc edge III of segment E, and the other end is connected to the arc edge VI of segment B. The arc edges III of segment E, VIII of segment C, VI of segment B, and IV of segment A are connected to form a smooth arc edge.

[0017] Furthermore, the length of the straight edge I of block F is an integer multiple of the length of the short edge of block D; the length of the long straight edge of block E is an integer multiple of the length of the short edge of block D.

[0018] Furthermore, corner reinforcing sheets are provided on both the front and back sides near the corners of the planar film.

[0019] A shape-maintaining system for a planar thin film for a deployable thin film antenna, wherein the planar thin film 1 has a total of n corners, characterized in that the shape-maintaining system comprises: n high-precision tension adjustment devices, n+1 rope tube patch groups, and n+1 tension cables;

[0020] n high-precision tension adjustment devices are installed one-to-one at n corner points; each high-precision tension adjustment device can connect to two tension cables.

[0021] n+1 rope tube patch groups are arranged one-to-one on the n+1 arc edges of the planar film. Each rope tube patch group includes several rope tube patches. The rope tube patches in each rope tube patch group are arranged sequentially along the arc edge and are fixedly connected to the planar film to form an arc-shaped rope channel.

[0022] n+1 tension cables are arranged one-to-one in the arc-shaped rope track. One end of each tension cable extends out of the arc-shaped rope track and is connected to the corresponding high-precision tension adjustment device on the same side. The other end extends out of the other end of the arc-shaped rope tube patch track and is connected to another high-precision tension adjustment device on the same side. By adjusting the high-precision tension adjustment devices at both ends of each tension cable, the tension of the tension cable is adjusted, so that the planar film is flattened and the flat surface is maintained.

[0023] Furthermore, the rope tube patch includes a patch and a rope tube. The patch has an axisymmetric structure and is integrally formed from two isosceles trapezoidal films and two rectangular films. The upper bases of the two isosceles trapezoidal films are connected, and the lower bases of the two isosceles trapezoids are respectively connected to the long sides of the two rectangular films. The length of the upper base of the isosceles trapezoidal film is the same as the length of the rope tube, and the length of the lower base of the isosceles trapezoidal film is the same as the length of the long side of the rectangular film.

[0024] The patch is folded along the straight line of the upper base of the isosceles trapezoidal film. The inner surface of each isosceles trapezoidal film is a non-adhesive area, and the inner surface of each rectangular film is an adhesive area. The rope tube patch is glued to the front and back of the flat film through the adhesive areas of the two rectangular films of each patch, thus fixing the rope tube patch to the arc edge of the flat film.

[0025] The rope tube is fixed at the inner fold line of the folded patch and is used to pass the tension cable.

[0026] Furthermore, the diameter of the rope tube is larger than that of the tension cable, and both the inner surface of the rope tube and the outer surface of the tension cable are lubricated with grease.

[0027] Furthermore, the high-precision tension adjustment device includes: a mounting base, a sliding plate, two turnbuckles, two springs, two fine-tuning devices, and two ropes;

[0028] The skateboard has a long, flat structure with a mounting base at one end. The skateboard is mounted on the outer frame via the mounting base. Turnbuckles, springs, and ropes are all installed along the length of the skateboard. Specifically, two turnbuckles are installed side by side. One end of each turnbuckle is fixedly connected to the mounting base, and the other end is connected to one end of a rope via a spring. The other end of the rope is connected to a swivel. The end of the tension cable is connected to the swivel via a fine-tuning device.

[0029] The fine-tuning device is used in conjunction with the tension cable to adjust the angle of the tension cable so that the natural extension direction of the tension cable at the end of the arc-shaped rope path is the length direction of the rope tube patch at the end of the arc-shaped rope path.

[0030] Furthermore, the fine-tuning device includes a bracket, a screw, a sheave seat, and a sheave;

[0031] The fine-tuning device is mounted on the high-precision tension adjustment device via a bracket;

[0032] The support is a frame structure. One end of the support is provided with a threaded hole, and the other end is provided with a guide groove along the length of the support. The rope wheel seat is set in the guide groove. Under the limitation of the side wall of the support, the rope wheel seat can only move back and forth in a straight line along the guide groove.

[0033] One end of the screw is installed in conjunction with the threaded hole of the bracket, and the other end is connected to the rope sheave seat through an angular contact bearing. Rotating the screw can drive the rope sheave seat to move in the guide groove. The rope sheave seat is provided with two opposing legs. The rope sheave adopts a V-type bearing and is set between the two opposing legs through a shaft. The outer circumference of the V-type bearing is provided with a V-groove for cooperating with the tension cable and guiding the tension cable. The end of the tension cable passes through the V-groove of the rope sheave and is connected to the cable ring.

[0034] Furthermore, two slides are provided on the end of the skateboard opposite to the mounting base. The two slides are located on both sides of the spring. Two fine-tuning devices are installed in conjunction with the slides through brackets. The rope wheels of the two fine-tuning devices are arranged opposite each other, and each fine-tuning device can move back and forth along the slide.

[0035] Beneficial effects:

[0036] (1) The planar thin film in this invention is made of four or more modular blocks spliced ​​together, which can not only meet the large size requirements of the planar thin film antenna, but also adjust the number of modules according to the size requirements of the planar thin film antenna.

[0037] (2) In this invention, when each short side of the planar film is provided with two corner points and the planar film is spliced ​​together from six different shapes, the six modular blocks are block A, block B, block C, block D, block E and block F. After splicing, there is no cross-shaped splicing seam, which ensures the flatness of the splicing seam. If the size of the film is further increased, this segmentation form is still applicable.

[0038] (3) The planar film of the present invention is provided with corner reinforcing plates on both the front and back sides near the corners to strengthen the strength of the planar film near the corners where the stress is concentrated, and to prevent the planar film at the corners from breaking.

[0039] (4) The surface maintenance system of the present invention includes a high-precision tension adjustment device and rope tube patches discretely arranged along the arc edge of the planar film. Each tension cable passes through the arc-shaped rope channel formed by the rope tube patch, and both ends are connected to the high-precision tension adjustment device. The tension of the tension cable is precisely adjusted by the high-precision tension adjustment device, and the strength of the edge of the planar film is strengthened by the discretely arranged rope tube patches, so that the planar film can be uniformly stressed.

[0040] (5) The rope tube patch of the present invention is fixed to the arc edge of the flat film by bonding the two rectangular films of each patch to the front and back sides of the flat film respectively. The bonding of the rope tube patch to the front and back sides of the flat film by bonding the two rectangular films of each patch can ensure the bonding strength between the rope tube patch and the film surface; and ensure the tension of the rope on the flat film.

[0041] Furthermore, the rope tube of this invention is fixedly installed at the inner fold line of the folded patch, and is used to pass the tension cable. The installation of the rope tube prevents the tension cable from directly contacting the flat film, thus avoiding a large number of wrinkles on the flat film.

[0042] Furthermore, the isosceles trapezoidal film on the rope tube patch facilitates the threading of the rope after the rope tube patch is fixed.

[0043] (6) The inner surface of the rope tube and the outer surface of the tension cable of the present invention are both provided with grease for lubrication, which reduces the friction between the tension cable and the rope tube, thereby improving the stress uniformity of the planar film after tensioning and further avoiding a large number of wrinkles in the planar film.

[0044] (7) In the high-precision tension adjustment device of the present invention, one end of each turnbuckle is fixedly connected to the mounting base, and the other end is connected to one end of a rope through a spring. The other end of the rope is connected to a sling. The end of the tension cable is connected to the sling after passing through a fine adjustment device. The turnbuckle uses fine thread. By adjusting the length of the turnbuckle, the tension spring drives the rope to apply tension to the tension cable, and the tension of the tension cable can be precisely adjusted.

[0045] (8) The rotating screw in the fine-tuning device of the present invention can drive the rope wheel seat to move in the guide groove. The rope wheel adopts a V-type bearing and is set between two opposite support legs through a shaft. The outer circumference of the V-type bearing is provided with a V-shaped groove for cooperating with the tension cable and guiding the tension cable. After the end of the tension cable passes through the V-shaped groove of the rope wheel, it is connected to the cable ring. By rotating the screw, the end of the tension cable can pass through the V-shaped groove tangentially with the rope wheel, and the natural extension direction of the tension cable at the end of the arc-shaped rope channel is the length direction of the rope tube patch at the end of the arc-shaped rope channel. The angle of the tension cable is precisely adjusted to prevent the rope at the corner of the film from cutting the film and to effectively ensure the uniformity of the force at the corner of the planar film.

[0046] (9) The fine-tuning device of the present invention can move back and forth along the slide rail on the slide plate, which can roughly adjust the position of the rope wheel before precisely adjusting the angle of the tension cable, speeding up the adjustment speed and increasing the movement distance of the rope wheel.

[0047] In summary, this application enables the achievement of sub-millimeter-level flatness and stress uniformity of over 90% for large-area planar thin-film antenna structures, thus meeting the requirements for uniform tension and high precision in large-area planar thin-film antenna structures. Attached Figure Description

[0048] Figure 1 This is a schematic diagram of the unfolded planar thin film;

[0049] Figure 2 This is a schematic diagram of planar thin film segmentation;

[0050] Figure 3This is a schematic diagram of a shape-maintaining system;

[0051] Figure 4 This is a schematic diagram of a partial rope tube patch layout;

[0052] Figure 5 This is a schematic diagram of the rope tube patch structure;

[0053] Figure 6 This is a schematic diagram of a high-precision tension adjustment device;

[0054] Figure 7 This is a schematic diagram of the fine-tuning device;

[0055] Figure 8 This is a detailed schematic diagram of tensioning at the corner points along the length of a planar thin film;

[0056] Figure 9 This is a detailed schematic diagram of tensioning at the corner points along the width direction of a planar thin film;

[0057] Among them, 1-flat film, 2-high-precision tension adjustment device, 3-rope tube patch, 4-corner, 41-corner point, 42-corner reinforcing plate, 5-tension cable, 6-mounting base, 7-slide plate, 8-turnbuckle, 9-spring, 10-fine adjustment device, 11-rope, 12-rope ring, 13-bracket, 14-screw, 15-rope pulley seat, 16-rope pulley, 17-bonded area, 18-non-bonded area, 19-rope tube. Detailed Implementation

[0058] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0059] Example 1:

[0060] This embodiment provides a planar thin film for a deployable thin-film antenna, see attached figure. Figure 1 The unfolded planar film 1 consists of a rectangular structure and two or more protruding corner portions 4 on each short side of the rectangular structure and two or more protruding corner portions 4 on each long side of the rectangular structure. Each corner portion 4 has a corresponding corner point 41, and adjacent corner points 41 are transitioned by concave arc edges. The two short sides of the planar film 1 are symmetrical to each other, and the two long sides are symmetrical to each other. In a specific embodiment, each short side of the planar film 1 has two protruding corner portions 4, and each long side has five protruding corner portions 4.

[0061] Let the total number of corners 4 on the planar film 1 be n, where the total number of corners 4 set on the short side is n1, and the total number of corners 4 set on the long side is n2, and n = n1 + n2;

[0062] The planar thin film 1 is composed of four or more modular segments spliced ​​together;

[0063] See appendix Figure 2 When n1 = 4, and the planar thin film 1 is spliced ​​from six modular blocks, the six modular blocks are block A, block B, block C, block D, block E and block F. Among them, the number of blocks A and block B is n1 = 4, the number of blocks C is two, the number of blocks D is several, the number of blocks E is four, and the number of blocks F is n2 - the number of blocks E, that is, n2 - 4.

[0064] Wherein, block D is a rectangle;

[0065] Block F has a triangular structure, with three sides: a straight side I and two concave arc sides I. The length of the straight side I is an integer multiple of the length of the short side of block D.

[0066] Block E is a planar quadrilateral structure. The four sides of the planar quadrilateral structure are a long straight side, a short straight side, a concave curved side II, and a concave curved side III. One end of the short straight side is perpendicularly connected to the long straight side, and the other end of the short straight side is connected to the concave curved side III. The concave curved side II and the concave curved side III are adjacent. Among them, the length and curvature of the curved side II are the same as those of the curved side I of block F. The length of the long straight side is an integer multiple of the length of the short side of block D.

[0067] A rectangular block formed by sequentially connecting several segments D constitutes the rectangular structure of the planar thin film 1. Segments E and F are both connected to the long side of the rectangular block. n2-4 segments F are divided into two groups and connected to the middle of the two long sides of the rectangular block respectively. The four segments E are connected one-to-one to the two ends of the two long sides of the rectangular block. The straight edge I of each segment F is connected to the long side of the rectangular block. The arc edges I on two adjacent segments F are joined to form a smooth arc edge. The long straight edge of each segment E is connected to the long side of the rectangular block, and the short straight edge is on the same straight line as the short side of the rectangular block. The arc edge II is joined to the arc edge I of segment F to form a smooth arc edge.

[0068] Block A has a triangular structure, with three sides being an inwardly concave curved side IV, an inwardly concave curved side V, and a straight side II. Block B has a trapezoidal structure, with two legs I being inwardly concave curved sides VI and VII. The length of the upper base I of the trapezoidal structure is the same as the length of the straight side II of block A. The straight side of block A connects with the upper base I of block B to form the corner 4 of the short side of the planar film 1. The curved side IV of block A and the curved side VI of block B are smoothly joined together. The curved side V of block A and the curved side VII of block B are smoothly joined together to form the curved side IX.

[0069] Block C is a trapezoidal structure. The length of the lower base II of the trapezoidal structure is the sum of the lengths of the short straight sides of the two blocks E and the length of the long side of block D. Both sides of the trapezoidal structure are concave arc-shaped sides VIII.

[0070] The middle of the lower base II of each segment C is connected to the short side of the corresponding rectangular block, and the two ends are connected to the short straight sides of the two corresponding segments E respectively; the two ends of the upper base II of each segment C are respectively connected to the lower base I of segment B, and the arc edges IX at both ends are set opposite to each other; the middle of the upper base II of each segment C is provided with an inward arc edge X, and the inward arc edge X and the arc edges IX at both ends are respectively connected to form a smooth arc edge; one end of the arc edge VIII of each segment C is connected to the arc edge III of segment E, and the other end is connected to the arc edge VI of segment B. The arc edges III of segment E, VIII of segment C, VI of segment B, and IV of segment A are connected to form a smooth arc edge.

[0071] The above-mentioned segmentation method ensures that there are no "cross seams" in the segments of the planar film 1, guarantees the flatness of the splicing seams, and adopts a modular segmentation method. If the size of the film is further increased, this segmentation method will still be applicable.

[0072] When the planar thin film 1 is spliced ​​together from four modular blocks, every two connected blocks A and B are integrally formed into a block G; the four modular blocks are blocks C, D, E and G.

[0073] When n2≥4, the corner 4 located between the corners of block A on the short side can be spliced ​​using new modular blocks.

[0074] In a specific embodiment, n1 = 4 and n2 = 10.

[0075] See appendix Figure 1 Corner reinforcing pieces 42 are provided on both the front and back sides near the corner point 41 of the planar film 1 to strengthen the strength near the corner point where the stress is concentrated. The corner reinforcing pieces 42 can be made of polyimide tape or polyimide composite gasket.

[0076] Example 2:

[0077] This embodiment, based on Embodiment 1, provides a shape-maintaining system for a planar thin film used in a deployable thin-film antenna. (See attached diagram.) Figure 3 It includes: n high-precision tension adjustment devices 2, n+1 rope tube patch groups and n+1 tension cables 5;

[0078] n high-precision tension adjustment devices 2 are set one-to-one at n corner points 41; each high-precision tension adjustment device 2 can connect to two tension cables 5;

[0079] See appendix Figure 4n+1 rope tube patch groups are arranged one-to-one on the n+1 arc edges of the planar film 1. Each rope tube patch group includes several rope tube patches 3. The several rope tube patches 3 in each rope tube patch group are arranged sequentially along the arc edge and are fixedly connected to the planar film 1 to form an arc-shaped rope channel.

[0080] n+1 tension cables 5 are arranged one-to-one in the arc-shaped rope track. One end of each tension cable 5 extends out of the arc-shaped rope track and is connected to the corresponding high-precision tension adjustment device 2 on the same side. The other end extends out of the arc-shaped rope track and is connected to another corresponding high-precision tension adjustment device 2 on the same side. By adjusting the high-precision tension adjustment devices 2 at both ends of each tension cable 5, the tension of the tension cable 5 is adjusted, so that the planar film 1 is flattened and the flat surface is maintained.

[0081] See appendix Figure 5 Each rope tube patch 3 includes a patch and a rope tube 19. The patch has an axisymmetric structure and is integrally formed from two isosceles trapezoidal films and two rectangular films. The upper bases of the two isosceles trapezoidal films are connected, and the lower bases of the two isosceles trapezoids are respectively connected to the long sides of the two rectangular films. The length of the upper base of the isosceles trapezoidal film is the same as the length of the rope tube 19, and the length of the lower base of the isosceles trapezoidal film is the same as the length of the long side of the rectangular film. The material of the patch is polyimide film.

[0082] The patch is folded along the straight line of the upper base of the isosceles trapezoidal film. The inner surface of each isosceles trapezoidal film is a non-adhesive area 18, and the inner surface of each rectangular film is an adhesive area 17. The rope tube patch 3 is glued to the front and back of the flat film 1 through the adhesive areas 17 of the two rectangular films of each patch, fixing the rope tube patch 3 to the arc edge of the flat film 1. The fact that the rope tube patch 3 is glued to the front and back of the flat film 1 through the adhesive areas 17 can ensure the bonding strength between the rope tube patch 3 and the film surface.

[0083] Rope tube 19 is fixedly installed at the inner fold line of the folded patch for the passage of tension cable 5; the isosceles trapezoidal film facilitates the threading of the rope tube patch 3 after it is fixed; since the rope tube patch 3 is straight and the arc edge of the planar film 1 is arc-shaped, and the planar film 1 is large in size, several discrete rope tube patches 3 are used to form the arc edge of the planar film 1 to ensure the stiffness of the planar film 1 during tensioning and that the planar film 1 and the tension cable 5 are subjected to uniform tension; when the rope tube patch 3 is bonded to the edge of the planar film 1, the positioning fixture is used to ensure the bonding accuracy of the rope tube patch 3 by referring to the results of the planar film form-finding analysis, and to ensure precise positioning, so as to further ensure that the planar film 1 and the tension cable 5 are subjected to uniform tension.

[0084] The diameter of the rope tube 19 is larger than that of the tension cable 5. The inner surface of the rope tube 19 and the outer surface of the tension cable 5 are both lubricated with grease to reduce the friction between the tension cable 5 and the rope tube 19, thereby improving the stress uniformity of the tensioned planar film 1 and avoiding a large number of wrinkles.

[0085] See appendix Figure 6 The high-precision tension adjustment device 2 includes: a mounting base 6, a sliding plate 7, two turnbuckles 8, two springs 9, two fine-tuning devices 10, and two ropes 11;

[0086] The skateboard 7 is a long, flat plate structure. The mounting base 6 is located at one end of the skateboard 7, and the skateboard 7 is mounted on the outer frame via the mounting base 6. Turnbuckles 8, springs 9, and ropes 11 are all arranged along the length of the skateboard 7. Specifically, two turnbuckles 8 are arranged side by side. One end of each turnbuckle 8 is fixedly connected to the mounting base 6, and the other end is connected to one end of a rope 11 via a spring 9. The other end of the rope 11 is connected to a sling 12. The end of the tension cable 5 is connected to the sling 12 via a fine-tuning device 10.

[0087] The fine-tuning device 10 is used to cooperate with the tension cable 5 to adjust the angle of the tension cable 5 so that the natural extension direction of the tension cable 5 at the end of the arc-shaped rope path is the length direction of the rope tube patch 3 at the end of the arc-shaped rope path (i.e., the tangent direction at the end of the arc edge of the planar film), to prevent the tension cable 5 or the rope tube patch 3 at the end of the arc-shaped rope path from being cut, and to ensure that the planar film 1 is subjected to high uniformity prestress.

[0088] See appendix Figure 7 The fine-tuning device 10 includes a bracket 13, a screw 14, a sheave seat 15, and a sheave 16. The bracket 13 has a frame structure, with a threaded hole at one end and a guide groove along the length of the bracket 13 at the other end. The sheave seat 15 is located in the guide groove and, limited by the side wall of the bracket 13, can only reciprocate linearly along the guide groove. The screw 14 has a fine thread, with one end fitted into the threaded hole of the bracket 13 and the other end connected to the sheave seat 15 via an angular contact bearing. Rotating the screw 14 can drive the sheave seat 15 to move within the guide groove. The sheave seat 15 has two opposing legs. The sheave 16 uses a V-bearing and is positioned between the two opposing legs via a shaft. The outer circumference of the V-bearing has a V-groove for engaging with the tension cable 5 and guiding it. The end of the tension cable 5 passes through the V-groove of the sheave 16 and connects to the cable ring 12.

[0089] Two slides are provided on one end of the skateboard 7 opposite to the mounting base 6. The two slides are located on both sides of the spring 9. Two fine adjustment devices 10 are installed in conjunction with the slides through the bracket 13. The rope wheels 16 of the two fine adjustment devices are arranged opposite each other. Each fine adjustment device 10 can move back and forth along the slide.

[0090] Working principle:

[0091] Each tension cable 5 is fixed to the arc-shaped rope channel formed by discrete rope tube patches 3 on the arc edge of the planar membrane 1; the end of the tension cable 5 is connected to the rope sheave 16 through the V-groove of the rope sheave 16 and then to the cable ring 12; see Figure 8 and Figure 9 The position of the rope wheel 16 is roughly adjusted by adjusting the position of the fine-tuning device 10 on the slide, and the position of the rope wheel 16 is precisely adjusted by rotating the screw 14 so that the end of the tension cable 5 passes through the V-groove tangent to the rope wheel 16, and the natural extension direction of the tension cable 5 at the end of the arc-shaped rope path is the length direction of the rope tube patch 3 at the end of the arc-shaped rope path; by adjusting the length of the turnbuckle 8, the tension spring 9 drives the rope 11 to apply tension to the tension cable 5.

[0092] By combining a high-precision tension adjustment device and a discrete rope tube patch 3, the tension and angle of the tension cable 5 can be precisely adjusted to prevent the rope 11 at the corner of the film from cutting the film. This effectively ensures the uniformity of stress at the corner of the film tensioning and solves the problem of wrinkles easily occurring at the corner in current tensioning designs. This application can achieve sub-millimeter-level flatness and stress uniformity of over 90% for large-area planar thin-film antenna structures, meeting the requirements of uniform tension and high precision for large-area planar thin-film antenna structures.

[0093] In summary, the above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A planar thin film for a deployable thin-film antenna, characterized in that, The unfolded planar film consists of a rectangular structure and two or more protruding corners on each short side of the rectangular structure and two or more protruding corners on each long side of the rectangular structure. Each corner has a corresponding corner point, and adjacent corner points are transitioned by concave arc edges. The two short sides of the planar film are symmetrical to each other, and the two long sides are symmetrical to each other. The planar film is composed of four or more modular segments spliced ​​together, and the splicing seams between the segments are not cross seams. Let the total number of corners set on the short side of the planar thin film be The total number of corners set on the long side is ; when When the planar thin film is composed of six modular blocks, the six modular blocks are block A, block B, block C, block D, block E, and block F, wherein the number of blocks A and block B is 1 / 2. There are two blocks C, several blocks D, four blocks E, and one block F. - Number of blocks E, i.e. ; Wherein, block D is a rectangle; Block F has a triangular structure, with the three sides of the triangle being a straight side I and two concave arc-shaped sides I. Block E is a planar quadrilateral structure. The four sides of the planar quadrilateral structure are a long straight side, a short straight side, a concave arc side II, and a concave arc side III. One end of the short straight side is perpendicularly connected to the long straight side, and the other end of the short straight side is connected to the concave arc side III. The concave arc side II and the concave arc side III are adjacent. A rectangular block formed by sequentially connecting several segments D constitutes the rectangular structure of the planar thin film. Segments E and F are both connected to the long side of the rectangular block. Each block F is divided into two groups and connected to the middle of the two long sides of the rectangular block. Four blocks E are connected one-to-one to the two ends of the two long sides of the rectangular block. The straight edge I of each block F is connected to the long side of the rectangular block. The arc edges I on two adjacent blocks F are joined together to form a smooth arc edge. The long straight edge of each block E is connected to the long side of the rectangular block, and the short straight edge is on the same straight line as the short side of the rectangular block. The arc edge II is joined to the arc edge I of block F to form a smooth arc edge. Block A has a triangular structure with three sides: a concave arc side IV, a concave arc side V, and a straight side II. Block B has a trapezoidal structure with two legs I: a concave arc side VI and a concave arc side VII. The length of the upper base I of the trapezoidal structure is the same as the length of the straight side II of block A. The straight side of block A connects with the upper base I of block B to form the corner of the short side of the planar film. The arc side IV of block A and the arc side VI of block B are smoothly joined together. The arc side V of block A and the arc side VII of block B are smoothly joined together to form the arc side IX. Block C is a trapezoidal structure. The length of the lower base II of the trapezoidal structure is the sum of the lengths of the short straight sides of the two blocks E and the length of the long side of block D. Both sides of the trapezoidal structure are concave arc-shaped sides VIII. The middle of the lower base II of each segment C is connected to the short side of the corresponding rectangular block, and the two ends are connected to the short straight sides of the two corresponding segments E respectively; the two ends of the upper base II of each segment C are respectively connected to the lower base I of segment B, and the arc edges IX at both ends are set opposite to each other; the middle of the upper base II of each segment C is provided with a concave arc edge X, and the concave arc edge X and the arc edges IX at both ends are respectively connected to form a smooth arc edge; one end of the arc edge VIII of each segment C is connected to the arc edge III of segment E, and the other end is connected to the arc edge VI of segment B. The arc edges III of segment E, VIII of segment C, VI of segment B, and IV of segment A are connected to form a smooth arc edge.

2. The planar thin film for a deployable thin-film antenna as described in claim 1, characterized in that, The length of the straight edge I of block F is an integer multiple of the length of the short edge of block D; the length of the long straight edge of block E is an integer multiple of the length of the short edge of block D.

3. A planar thin film for a deployable thin-film antenna as described in claim 1 or 2, characterized in that, Corner reinforcing sheets are provided on both the front and back sides near the corners of the planar film.

4. A shape-maintaining system for a planar thin film for a deployable thin-film antenna, based on the planar thin film for a deployable thin-film antenna as described in claim 1, wherein the total number of corners on the planar thin film is... One, characterized in that, The shape-maintaining system includes: A high-precision tension adjustment device; A set of rope tube patches and Tensioner cable; Each high-precision tension adjustment device is installed in a corresponding manner. At each corner point; each high-precision tension adjustment device can connect two tension cables; Each rope tube patch group is set one-to-one on the flat film. On each arc edge, each rope tube patch group includes several rope tube patches. The several rope tube patches in each rope tube patch group are arranged sequentially along the arc edge and are fixedly connected to the planar film to form an arc-shaped rope channel. Each tension cable is set in a corresponding arc-shaped rope track. One end of each tension cable extends out of the arc-shaped rope track and is connected to the corresponding high-precision tension adjustment device on the same side. The other end extends out of the other end of the arc-shaped rope tube patch track and is connected to another corresponding high-precision tension adjustment device on the same side. By adjusting the high-precision tension adjustment devices at both ends of each tension cable, the tension of the tension cable is adjusted, so that the planar film is flattened and the flat surface is maintained.

5. The shape and surface maintenance system for a planar thin film for a deployable thin-film antenna as described in claim 4, characterized in that, The rope tube patch includes a patch and a rope tube. The patch has an axisymmetric structure and is integrally formed from two isosceles trapezoidal films and two rectangular films. The upper bases of the two isosceles trapezoidal films are connected, and the lower bases of the two isosceles trapezoids are respectively connected to the long sides of the two rectangular films. The length of the upper base of the isosceles trapezoidal film is the same as the length of the rope tube, and the length of the lower base of the isosceles trapezoidal film is the same as the length of the long side of the rectangular film. The patch is folded along the straight line of the upper base of the isosceles trapezoidal film. The inner surface of each isosceles trapezoidal film is a non-adhesive area, and the inner surface of each rectangular film is an adhesive area. The rope tube patch is glued to the front and back of the flat film through the adhesive areas of the two rectangular films of each patch, thus fixing the rope tube patch to the arc edge of the flat film. The rope tube is fixed at the inner fold line of the folded patch and is used to pass the tension cable.

6. The shape and surface maintenance system for a planar thin film for a deployable thin-film antenna as described in claim 5, characterized in that, The diameter of the rope tube is larger than that of the tension cable, and both the inner surface of the rope tube and the outer surface of the tension cable are lubricated with grease.

7. The shape-maintaining system for a planar thin film for a deployable thin-film antenna as described in any one of claims 4-6, characterized in that, The high-precision tension adjustment device includes: a mounting base, a sliding plate, two turnbuckles, two springs, two fine-tuning devices, and two ropes; The skateboard has a long, flat structure with a mounting base at one end. The skateboard is mounted on the outer frame via the mounting base. Turnbuckles, springs, and ropes are all installed along the length of the skateboard. Specifically, two turnbuckles are installed side by side. One end of each turnbuckle is fixedly connected to the mounting base, and the other end is connected to one end of a rope via a spring. The other end of the rope is connected to a swivel. The end of the tension cable is connected to the swivel via a fine-tuning device. The fine-tuning device is used in conjunction with the tension cable to adjust the angle of the tension cable so that the natural extension direction of the tension cable at the end of the arc-shaped rope path is the length direction of the rope tube patch at the end of the arc-shaped rope path.

8. The shape and surface maintenance system for a planar thin film for a deployable thin-film antenna as described in claim 7, characterized in that, The fine-tuning device includes a bracket, a screw, a sheave seat, and a sheave. The fine-tuning device is mounted on the high-precision tension adjustment device via a bracket; The support is a frame structure. One end of the support is provided with a threaded hole, and the other end is provided with a guide groove along the length of the support. The rope wheel seat is set in the guide groove. Under the limitation of the side wall of the support, the rope wheel seat can only move back and forth in a straight line along the guide groove. One end of the screw is installed in conjunction with the threaded hole of the bracket, and the other end is connected to the rope sheave seat through an angular contact bearing. Rotating the screw can drive the rope sheave seat to move in the guide groove. The rope sheave seat is provided with two opposing legs. The rope sheave adopts a V-type bearing and is set between the two opposing legs through a shaft. The outer circumference of the V-type bearing is provided with a V-groove for cooperating with the tension cable and guiding the tension cable. The end of the tension cable passes through the V-groove of the rope sheave and is connected to the cable ring.

9. The shape and surface maintenance system for a planar thin film for a deployable thin-film antenna as described in claim 8, characterized in that, Two slides are provided on one end of the skateboard opposite the mounting base. The two slides are located on both sides of the spring. Two fine-tuning devices are installed in conjunction with the slides through brackets. The rope wheels of the two fine-tuning devices are arranged opposite each other, and each fine-tuning device can move back and forth along the slide.

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