Space-adjustable large space film unfolding structure based on folding triangular prism mechanism units

Abstract

The invention discloses a space-adjustable large space film unfolding structure based on folding triangular prism mechanism units, belongs to the technical field of spacecraft structures and space unfolding mechanisms, and aims at solving the problems that an existing film unfolding structure is low in storage ratio, poor in self-locking performance and poor in space adjusting capacity. The two ends of the folding triangular prism stretching device are each provided with a side carbon fiber baffle, and the film is arranged in a stretching frame composed of the folding triangular prism stretching device and the two side carbon fiber baffles and fixedly connected with the stretching frame through a plurality of catenary lines. The folding triangular prism stretching device serves as a power source to drive the thin film and the stretching frame to stretch or retract synchronously. The thin film stretching device is mainly used for carrying out stretching and retracting operation on a single-layer or multi-layer thin film structure of any size.

Description

TECHNICAL FIELD

[0002] The present application relates to the technical field of spacecraft structures and space deployable mechanism, and particularly relates to a large space thin film deployment structure with adjustable spacing based on a folded triangular prism mechanism unit. BACKGROUND

[0003] In the field of aerospace engineering, large thin film structures have become the core components of key devices such as solar sails, large antenna reflectors, space telescope sunshields, and deployable thermal control screens due to their core advantages of lightweight and large deployment area ratio. The working environment of such structures is extremely special, and they need to withstand high-intensity mechanical loads during the launch phase and complex conditions such as vacuum and temperature changes during the on-orbit phase. Therefore, the deployable mechanism that supports the deployment and retraction functions of these structures has multiple stringent requirements. On the one hand, the space of the fairing of the launch vehicle is limited during the launch process, so the mechanism needs to have a very high packing ratio to maximize the use of space and reduce launch costs. On the other hand, after deployment in orbit, the mechanism needs to be reliably locked and maintain sufficient structural stiffness to avoid distortion of the thin film surface due to factors such as orbital microgravity and solar radiation pressure, ensuring the functional accuracy of the device. In addition, for scenarios where multiple thin films work together, precise regulation of the spacing between the thin film layers is also required, while ensuring the synchronization, controllability of movement, and long-term on-orbit stability during the deployment process. Current traditional deployable mechanisms used in the field of aerospace have their own characteristics, but they all have significant shortcomings and cannot fully meet the above requirements. As a mature traditional solution, the articulated link mechanism has a simple structure design and mature manufacturing process. However, due to the articulated link method, there is still a lot of redundant space after folding, and the packing ratio is generally low. In addition, the joint gap after deployment can lead to insufficient structural stiffness, and long-term on-orbit micro-vibration can affect the accuracy of the thin film surface. At the same time, this type of mechanism is mostly custom-designed and cannot be modularly expanded to adapt to the needs of thin film structures of different sizes and layers. The coiled mast mechanism has a certain improvement in packing ratio compared to the articulated link mechanism by coiling the rigid mast along the axial direction. However, the deployment process relies on the elastic restoring force of the mast itself, making it difficult to control the driving force and resulting in poor synchronization. In addition, it can only achieve linear expansion in a single direction and cannot adapt to the support and spacing adjustment needs of multiple thin films. Furthermore, the torsional stiffness of the coiled structure is weak, and it lacks the ability to uniformly pull large-scale thin films, which can lead to uneven tension and wrinkles in the thin films. The inflatable deployment mechanism achieves structure deployment by inflating and expanding, resulting in a very high packing ratio and light weight and fast deployment speed. However, the structural stiffness after deployment completely depends on the internal gas pressure, which can fluctuate under the influence of temperature changes in the on-orbit environment, leading to poor structural stability. At the same time, the gas tightness requirement of the inflatable structure is extremely high, and there is a risk of air leakage during long-term on-orbit operation. Moreover, once a failure occurs, it is difficult to repair on-orbit, resulting in insufficient reliability. The folded tri-prism mechanism has been preliminarily explored in small deployable structures due to its compact structure, excellent folding performance, simple and reliable structure and the like. However, the existing technology fails to fully tap the application potential of the folded tri-prism mechanism. On the one hand, the existing solutions are mostly single-unit designs, lack a modular expansion mechanism, and cannot form large-scale support structures through unit splicing, making it difficult to adapt to the deployment and retraction requirements of large films. On the other hand, the existing solutions fail to integrate precise spacing adjustment functions, and can only satisfy the deployment of single-layer films, failing to adapt to scenarios where multiple layers of films work together. In addition, the driving system design of the existing solutions is complex, and multiple motors are mostly used for independent driving, resulting in poor deployment synchronization and complicated control logic, and the existing solutions fail to form an antagonistic locking mechanism for deployment and retraction ropes, resulting in insufficient structural stiffness after deployment. In recent years, with the advancement of deep space exploration, space station expansion modules, large space telescopes and other space missions, the requirements for the size, number of layers, surface accuracy and on-orbit service life of large film structures continue to increase, and the performance shortcomings of traditional mechanisms are increasingly prominent. At the same time, modular design and on-orbit maintainability have become important development trends for space structures. The existing mechanisms are mostly designed as a whole, and a single component failure can cause the entire system to fail, and the mechanisms cannot be repaired on-orbit by replacing units, seriously affecting mission reliability. In summary, there is a lack of an expandable structure solution in the existing technology that can integrate the core requirements of high storage ratio, self-driving and self-locking, precise spacing adjustment, modular expansion and high stiffness and stable support. Based on this, developing a large space film deployment structure with compact structure, high storage ratio, simple driving control, precise spacing adjustment and modular expansion has become a key technical pain point in the field of space deployable mechanisms, and is of great significance for promoting the widespread application of large film structures in space missions. SUMMARY

[0004] The present application provides a large space film deployment structure with adjustable spacing based on a folded tri-prism mechanism unit to solve the problems of low storage ratio, weak self-locking and poor spacing adjustment capability of existing film deployment structures. A large space film deployment structure with adjustable spacing based on a folded tri-prism mechanism unit, the space film deployment structure comprising a folded tri-prism deployment device, one side carbon fiber baffle is installed at each end of the folded tri-prism deployment device, a film is arranged in a deployment frame composed of the folded tri-prism deployment device and the two side carbon fiber baffles and fixedly connected to the deployment frame by a plurality of catenary lines, and the folded tri-prism deployment device drives the film and the deployment frame to perform synchronous expansion or contraction actions as a power source. Further, the folded tri-prism deployment device comprises an upper deployment mechanism and a lower deployment mechanism, the upper deployment mechanism and the lower deployment mechanism are arranged in parallel and opposite positions, and the two ends of the upper deployment mechanism and the two ends of the lower deployment mechanism are fixedly connected to corresponding side carbon fiber baffles. Further, the upper and lower stretching mechanisms have the same structure, and a plurality of intermediate connecting rods are equidistantly arranged between the upper and lower stretching mechanisms along the extension direction of the stretching frame, two ends of each intermediate connecting rod are respectively detachably connected with the corresponding upper or lower stretching mechanism, and the upper and lower stretching mechanisms are mechanically coupled through the plurality of intermediate connecting rods to form a double-sided unfolding system. Further, the upper stretching mechanism comprises a driving module, and one unfolding unit is mounted on each side of the driving module, and the driving module serves as a power source to drive the two unfolding units to synchronously perform stretching or contraction actions. Further, the unfolding unit comprises N connecting rod assemblies and N+1 regular triangular connecting frames, N is a positive integer, the N+1 regular triangular connecting frames are equidistantly arranged on one side of the driving module along the extension direction of the stretching frame, one connecting rod assembly is arranged between adjacent two regular triangular connecting frames, one end of each connecting rod assembly is hingedly connected with the adjacent regular triangular connecting frame, adjacent two connecting rod assemblies are connected through a plurality of synchronous ropes, the connecting rod assembly and the adjacent two regular triangular connecting frames form a triangular prism unfolding and folding unit, and adjacent two oppositely folded triangular prism unfolding and folding units form a folded triangular prism mechanism. Further, the connecting rod assembly comprises three connecting rods, the three connecting rods are arranged in parallel between the adjacent two regular triangular connecting frames, two ends of each connecting rod are respectively hingedly connected with the corresponding regular triangular connecting frame, and the two connecting rods coaxially arranged in the adjacent two connecting rod assemblies are connected through the synchronous rope. Further, the regular triangular connecting frame comprises an aluminum alloy square tube, two carbon fiber rods and three connecting joints, the aluminum alloy square tube and the two carbon fiber rods are arranged in a regular triangle, two ends of the aluminum alloy square tube are respectively connected with the corresponding carbon fiber rod through a connecting joint, and the two carbon fiber rods are connected through a connecting joint, and the aluminum alloy square tube is provided with a multilayer film spacing adjuster for connecting the catenary and a flange module for connecting the intermediate connecting rod. Further, the multilayer film spacing adjuster is connected with the catenary through a catenary connector. Further, the driving module comprises a box structure composed of an aluminum square frame and side plates, the box structure is provided with an unfolding rope winding wheel assembly and a folding rope winding wheel assembly, and the two ends of the box structure are respectively provided with a plurality of connecting blocks for connecting the unfolding units. Further, two unfolding ropes are wound on the unfolding rope winding wheel assembly, and each unfolding rope in the unfolding rope winding wheel assembly is arranged corresponding to one unfolding unit, two folding ropes are wound on the folding rope winding wheel assembly, and each folding rope in the folding rope winding wheel assembly is arranged corresponding to one unfolding unit, and the unfolding rope winding wheel assembly and the folding rope winding wheel assembly control the two unfolding units to synchronously perform the unfolding action through the two unfolding ropes and the two folding ropes.

[0005] The beneficial effects of the present application relative to the prior art are: 1. The present application provides a large space thin film deployment structure with adjustable spacing based on a folded triangular prism mechanism unit. The basic unit is a folded triangular prism unit, which is composed of only 6 revolute pairs. The structure is extremely simple and compact. In the fully folded state, the angle between the connecting rod and the equilateral triangle frame is 0°, and the units are stacked tightly, minimizing the transverse size. This solves the problem of redundant space and low storage ratio of traditional hinged link mechanisms, far surpassing the storage efficiency of most existing deployable mechanisms. It maximizes the use of launch vehicle fairing space, reduces launch costs, and through unit splicing, the folding logic of each module is consistent, and the overall folded state remains compact and regular, avoiding the pain of integrated design in large size scenarios.

[0006] 2. The present application provides a large space thin film deployment structure with adjustable spacing based on a folded triangular prism mechanism unit. By arranging a single deployment rope and a single folding rope along the diagonal of the folded triangular prism side, the two ropes are simultaneously tensioned after deployment, effectively reducing the joint clearance of the revolute pairs, and forming a high-stiffness triangular prism truss support structure. Compared with traditional hinged link mechanisms, which have micro-vibration problems, inflatable mechanisms, which rely on unstable air pressure, and coiled torsional stiffness, this solution can effectively avoid thin film surface distortion under complex conditions such as on-orbit microgravity and solar radiation pressure, ensuring equipment function accuracy. The present application forms a regular prism array structure after complete deployment, has strong longitudinal extension capability, and good thin film pulling uniformity, solving the problem of uneven thin film tension and wrinkles caused by traditional mechanisms, ensuring that the thin film remains flat on orbit for a long time.

[0007] 3. The present application provides a large space thin film deployment structure with adjustable spacing based on a folded triangular prism mechanism unit. Only one deployment rope and one folding rope are needed for each folded triangular prism unit and the expanded structure to achieve deployment and folding motion. This completely changes the status quo of traditional mechanisms with multiple motors driven independently and complex control logic, significantly reducing the design complexity and failure rate of the drive system. Through the cross-type synchronous rope transmission structure and coaxial transmission design within the drive assembly, all folded triangular prism units are synchronized, and the overall mechanism has only one degree of freedom. This solves the problems of poor deployment synchronization and difficult drive force control of coiled mast mechanisms, ensuring controllable and stable deployment, and avoiding uneven stress during thin film pulling.

[0008] 4. This application provides a large-scale space film deployment structure with adjustable spacing based on folded triangular prism mechanism units. It integrates a multi-layer film spacing adjustment device. By moving and locking the T-slot slider along the graduated T-slot, the distance between the multi-layer film and the reference surface can be precisely adjusted within the range of 0-20mm. This breaks through the limitation of traditional deployable mechanisms that can only adapt to single-layer films, meets the spacing control requirements in multi-layer film collaborative working scenarios, and adapts to different film tension and flatness requirements. On this basis, the modular design supports infinite expansion along one-dimensional direction. Theoretically, it can adapt to the deployment and retraction requirements of rectangular films of any size. Whether it is small equipment or large-scale structures such as large space telescope light shields and space station expansion modules, it can be adapted through unit splicing, solving the problem of poor versatility of traditional customized mechanisms. Attached Figure Description

[0009] Figure 1 This is a schematic diagram of the overall layout structure of a large-scale spatial thin film unfolding structure based on folded triangular prism mechanism units as described in this application. Figure 2 This is a schematic diagram of the initial state of a large-scale spatial thin film unfolding structure based on a folded triangular prism mechanism unit with adjustable spacing, as described in this application. Figure 3 This is a schematic diagram of the extended state of a large-scale spatial thin film unfolding structure based on folded triangular prism mechanism units as described in this application. Figure 4 This is a schematic diagram of the upper extension mechanism in a large-scale spatial thin film unfolding structure with adjustable spacing based on folded triangular prism mechanism units as described in this application. Figure 5 This is an illustration of the extension mechanism in a large-scale spatial thin film unfolding structure with adjustable spacing based on folded triangular prism mechanism units as described in this application. Figure 6 This is a folding diagram of the folding triangular prism mechanism in a large-scale spatial thin film unfolding structure with adjustable spacing based on a folding triangular prism mechanism unit as described in this application. Figure 7 This is a schematic diagram of the unfolded state of the folded triangular prism mechanism in a large-scale spatial thin film unfolding structure with adjustable spacing based on folded triangular prism mechanism units as described in this application. Figure 8 This is a schematic diagram of the folded triangular prism mechanism in a large-scale spatial thin film unfolding structure with adjustable spacing based on folded triangular prism mechanism units as described in this application. Figure 9 This is a schematic diagram of the connecting rod in a large-scale spatial thin film unfolding structure with adjustable spacing based on a folded triangular prism mechanism unit as described in this application. Figure 10This is a schematic diagram of the equilateral triangle connecting frame in a large-scale spatial thin film unfolding structure with adjustable spacing based on folded triangular prism mechanism units as described in this application. Figure 11 This is a schematic diagram of the multilayer film spacing adjuster in a large-scale spatial film unfolding structure based on a folded triangular prism mechanism unit, as described in this application. Figure 12 This is a schematic diagram of the T-shaped slider in a large-scale spatial thin film unfolding structure with adjustable spacing based on a folded triangular prism mechanism unit as described in this application. Figure 13 This is a rear view schematic diagram of the multilayer film spacing adjuster in a large-scale spatial film unfolding structure based on a folded triangular prism mechanism unit, as described in this application. Figure 14 This is a schematic diagram of the catenary connector in a large-scale spatial thin film unfolding structure with adjustable spacing based on a folded triangular prism mechanism unit as described in this application. Figure 15 This is a schematic diagram of the flange module in a large-scale space membrane unfolding structure with adjustable spacing based on a folded triangular prism mechanism unit as described in this application. Figure 16 This is a schematic diagram of the drive module in a large-scale spatial thin film unfolding structure with adjustable spacing based on a folded triangular prism mechanism unit as described in this application. Figure 17 This is a side view of the drive module in a large-scale spatial thin film unfolding structure with adjustable spacing based on a folded triangular prism mechanism unit as described in this application. Figure 18 This is a transmission diagram of the unfolding rope reel assembly and the retracting rope reel assembly in a large-scale spatial thin film unfolding structure with adjustable spacing based on a folding triangular prism mechanism unit as described in this application. Figure 19 This is an exploded view of the roller assembly in a large-scale spatial thin film unfolding structure with adjustable spacing based on a folded triangular prism mechanism unit as described in this application. Figure 20 This is an exploded view of the internal support shaft of the roller assembly in a large-scale spatial thin film unfolding structure with adjustable spacing based on a folded triangular prism mechanism unit as described in this application.

[0010] In the diagram: 1. Membrane; 2. Upper extension mechanism; 3. Lower extension mechanism; 4. Side carbon fiber baffle; 5. Intermediate connecting rod; 6. Catenary; 7. Connecting rod; 701. Rope hole 1; 702. Pin 1; 703. Rotating node 1; 704. Carbon fiber rod; 705. Rotating node 2; 706. Pin 2; 707. Rope hole 2; 8. Equilateral triangle connecting frame; 801. Carbon fiber diagonal rod; 802. Aluminum alloy square tube; 803. Connecting joint; 804. Guide wheel; 805. Multilayer film spacing adjuster; 805a. T-slot connecting block; 805b. T-slide block; 805b1. Connecting hole; 805b2. Mounting hole; 805c. Pressure cap; 805c1. Connecting through hole; 805c2. Locking threaded hole; 806. Flange module; 806b. Flange. 806b connecting plate, 806c first aluminum alloy square tube clamp, 806d second aluminum alloy square tube clamp; 807 catenary connector, 8071 round hole, 8072 clamping threaded hole, 8073 lifting lug, 9 unfolding rope, 10 retracting rope, 11 synchronous rope, 12 unfolding and retracting unit, 13 drive module, 14 membrane spacing adjuster interface, 15 aluminum square frame; 16 side plate; 17 unfolding rope drive motor, 171 first pulley, 18 retracting rope drive motor, 181 second pulley, 19 unfolding rope reel assembly, 1901 reel pulley, 1902 unfolding rope reel, 1903 end cover bearing seat, 19031 bearing, 1904 drive shaft, 1905 bushing, 20 retracting rope reel assembly, 21 synchronous belt and 22 connecting block. Detailed Implementation

[0011] Specific implementation method one: Combining Figures 1 to 5 This embodiment describes a large-scale spatial membrane unfolding structure with adjustable spacing based on a folded triangular prism mechanism unit. The spatial membrane unfolding structure includes a folded triangular prism extension device. A side carbon fiber baffle 4 is installed at each end of the folded triangular prism extension device. The membrane 1 is set in an extension frame composed of the folded triangular prism extension device and the two side carbon fiber baffles 4 and is fixedly connected to the extension frame by multiple catenary wires 6. The folded triangular prism extension device serves as a power source to drive the membrane 1 to extend or retract synchronously with the extension frame. The folding triangular prism extension device includes an upper extension mechanism 2 and a lower extension mechanism 3, which are arranged in parallel and opposite to each other. The two ends of the upper extension mechanism 2 and the two ends of the lower extension mechanism 3 are respectively fixedly connected to the corresponding side carbon fiber baffles 4. The upper extension mechanism 2 and the lower extension mechanism 3 have the same structure. Multiple intermediate connecting rods 5 are equidistantly arranged between the upper extension mechanism 2 and the lower extension mechanism 3 along the extension direction of the extension frame. The two ends of each intermediate connecting rod 5 are detachably connected to the corresponding upper extension mechanism 2 or lower extension mechanism 3. The upper extension mechanism 2 and the lower extension mechanism 3 are mechanically coupled through multiple intermediate connecting rods 5 to form a double-sided unfolding system. The upper extension mechanism 2 includes a drive module 13, and an extension unit 12 is installed on each side of the drive module 13. The drive module 13 acts as a power source to drive the two extension units 12 to extend or retract synchronously.

[0012] This embodiment describes a large-scale spatial film unfolding structure with adjustable spacing based on a folded triangular prism mechanism unit. It is mainly used to control the extension action of single-layer or multi-layer films during operation. Taking a single-layer film as an example, the edges of a rectangular film are cut to form a continuous arc-shaped lace structure. At this time, the rectangular film has formed a film 1 that can cooperate with the unfolding structure. Ropes are threaded into the lace structure of film 1, and catenary 6 is set at each corner point of each lace in film 1. The catenary 6 on the left and right sides of film 1 is connected to the corresponding side carbon fiber baffles 4 in the unfolding structure. The catenary 6 on the upper and lower sides of film 1 is connected to the upper extension mechanism 2 and the lower extension mechanism 3, respectively. Film 1 performs synchronous unfolding motion under the drive of the upper extension mechanism 2 and the lower extension mechanism 3. Through the cooperation of the upper extension mechanism 2 and the lower extension mechanism 3 with the catenary 6 connected to them, the film 1 is stretched at multiple points and uniformly, so that film 1 unfolds in one dimension from the folded state, reaches the predetermined tension and maintains a flat state. The unfolding process of multi-layer films is similar to that of single-layer films, and together they complete the tensioning and unfolding of the multi-layer film structure. To ensure the stability of the stretched state of the film 1, the upper stretching mechanism 2 and the lower stretching mechanism 3 in this embodiment are selected to be stretching mechanisms with the same structure. In order to improve the connection stability between the upper stretching mechanism 2 and the lower stretching mechanism 3 and the corresponding side carbon fiber baffle 4, a matching connection hole is processed on the side carbon fiber baffle 4 at the corresponding position of the upper stretching mechanism 2 and the lower stretching mechanism 3. The intermediate connecting rod 5 set between the upper stretching mechanism 2 and the lower stretching mechanism 3 can improve the synchronization of the upper stretching mechanism 2 and the lower stretching mechanism 3, and can also cooperate with the side carbon fiber baffle 4, which serves as a load-bearing beam, to enhance the overall bending stiffness of the stretching frame. Multiple film spacing adjuster interfaces 14 are equidistantly machined on the side carbon fiber baffle 4 along its length extension direction. The film spacing adjuster interfaces 14 are used to determine the connection position of the catenary 6 on the side carbon fiber baffle 4.

[0013] Specific Implementation Method Two: Combining Figures 6 to 15This embodiment is a further limitation of the first specific embodiment. The unfolding unit 12 includes N linkage assemblies and N+1 equilateral triangular connecting frames 8, where N is a positive integer. The N+1 equilateral triangular connecting frames 8 are arranged equidistantly on one side of the drive module 13 along the extension direction of the extension frame. A linkage assembly is provided between two adjacent equilateral triangular connecting frames 8. One end of each linkage assembly is hinged to the adjacent equilateral triangular connecting frame 8. Two adjacent linkage assemblies are connected by multiple synchronous ropes 10. The linkage assembly and two adjacent equilateral triangular connecting frames 8 form a triangular prism unfolding and retracting unit. Two adjacent opposing triangular prism unfolding and retracting units form a folding triangular prism mechanism. The linkage assembly includes three links 7, which are arranged parallel to each other between two adjacent equilateral triangular connecting frames 8. The two ends of each link 7 are respectively hinged to the corresponding equilateral triangular connecting frame 8, and the two links 7 arranged coaxially in two adjacent linkage assemblies are connected by a synchronous rope 11. The equilateral triangular connecting frame 8 includes an aluminum alloy square tube 802, two carbon fiber rods 801, and three connecting joints 803. The aluminum alloy square tube 802 and the two carbon fiber rods 801 are arranged in an equilateral triangle. Each end of the aluminum alloy square tube 802 is connected to a corresponding carbon fiber rod 801 via a connecting joint 803. The two carbon fiber rods 801 are connected via a connecting joint 803. A multi-layer film spacing adjuster 805 for connecting the catenary 6 and a flange module 806 for connecting the intermediate connecting rod 5 are installed on the aluminum alloy square tube 802. Other components and connection methods are the same as in specific embodiment one.

[0014] In this embodiment, the connecting rod 7 includes a carbon fiber rod 704. A first rotating node 703 is installed at one end of the carbon fiber rod 704, and a second rotating node 705 is installed at the other end. The carbon fiber rod 704 is hinged to the adjacent equilateral triangular connecting frame 8 via either the first or second rotating node 703. A first pin 702 is inserted into the connection end of the first rotating node 703 and the equilateral triangular connecting frame 8. The first pin 702 is interference-fitted with the lug at the end of the first rotating node 703 and clearance-fitted with the hinge portion on the equilateral triangular connecting frame 8. A circular plate with an end face diameter larger than the pin's end face diameter is provided on the outer end of the first pin 702, and a first rope hole 701 for cooperating with the synchronous rope 11 is machined on the circular plate. The second rotating node 705 is connected to the equilateral triangular connecting frame 8. A second pin 706 is inserted into the connecting end of the connecting frame 8. The second pin 706 is interference-fitted with the ear plate at the end of the second rotating node 705, and is clearance-fitted with the hinge part on the equilateral triangular connecting frame 8. A circular plate with an end face diameter larger than the end face diameter of the pin is provided on the outer end of the second pin 706. A second rope hole 707 for cooperating with the synchronous rope 11 is machined on the circular plate. When the synchronous rope 11 is connected with the two rotating nodes, the synchronous rope 11 is first wound around the two circular plates located on the same side of the two rotating nodes in a cross-winding manner. The two ends of the synchronous rope 11 pass through the first rope hole 701 and the second rope hole 707 respectively, and then are knotted on the outside of the circular plate to prevent the synchronous rope 11 from sliding with the circular plate and losing its original function when the first rotating node 703 or the second rotating node 705 is working. The equilateral triangular end face frame 8 is composed of three connecting joints 803, two carbon fiber diagonal rods 801, and an aluminum alloy square tube 802. The carbon fiber rods 801 and the aluminum alloy square tube 802 are glued to the three connecting joints 803 to form an integral triangular frame structure. At each end of the connecting joint 803, a hinge lug for connecting to the connecting rod 7 is fixed. A roller 804 for guiding the unfolding rope 9 and the retracting rope 10 is also installed on the connecting joint 803. The roller 804 has two rope grooves, which are respectively set to one unfolding rope 9 or one retracting rope 10. In order to realize the adjustment of the multi-layer film spacing, a film spacing adjuster 805 is installed on the aluminum alloy square tube 802 of the equilateral triangular end face frame 8. The film spacing adjuster 805 includes a T-slot connecting block 805a, a T-slot slider 805b, and a pressure cap 805c. The principle of the multi-layer film spacing adjuster 805 for adjusting the spacing of multi-layer films is as follows: the T-slot slider 805a is designed with a T-shaped groove; the T-slot slider 805b is embedded in the T-shaped groove and can slide along the length of the T-shaped groove. The T-slot slider 805b is machined with a mounting hole 806b2 for connecting with the T-slot slider 806a and a connecting hole 806b1 for connecting with the catenary connector 808. The T-slot slider 806b can be locked at any position on the T-slot slider 805a using screws. For the film 1, the lace node on the film 1 is connected to one end of the catenary 6, and the other end of the catenary 6 is connected to the catenary connector 807. The specific connection method is as follows: the catenary 6 extends into the catenary connector 807 through the round hole 8071, and is clamped by the clamping thread hole 8072 on the side and the set screw. The set screw structure achieves a fixed connection between the catenary connector 807 and the catenary 6. The other end of the catenary connector 807 has a lug 8073 as shown in the figure. The lug 8073 has a connecting through hole machined on its side. This lug can be hinged to the connecting hole 805b1 on the T-shaped slider 805b in the multilayer film pitch adjuster 805 via a pin to form a rotating pair. This achieves the connection between the multilayer film pitch adjuster 805 and the catenary 6. The connection between the thin-film pitch connector 805 and the equilateral triangular end face frame 8 is achieved using a T-slot connecting block 805b and a pressure cap 805c. Both the T-slot connecting block 805b and the pressure cap 805c have rectangular grooves on one side for mating with the aluminum alloy square tube 802. Furthermore, threaded holes are machined on the surface of the T-slot connecting block 805b. Screws pass through the connecting through-hole 805c1 on the pressure cap 805c and engage with the threaded hole on the T-slot connecting block 805b. The aluminum alloy square tube 802 is located within the rectangular grooves of the T-slot connecting block 805b and the pressure cap 805c. A locking threaded hole 805c2 is machined on the back side of the pressure cap 805c. Tightening the screws achieves a fixed connection between the T-slot connecting block 805b and the pressure cap 805c and the aluminum alloy square tube 802, thereby achieving a fixed connection of the thin-film pitch adjuster 806 on the equilateral triangular end face frame 8. The specific process of adjusting the spacing of the multilayer film 1 using the film spacing adjuster 805 is as follows: when it is necessary to adjust the distance between different films, the T-slider 805b is moved to the target position along the T-slot in the T-slot connecting block 805a, and the screw is tightened again. This changes the anchor point position of the catenary 6, thereby precisely adjusting the distance between the film layer controlled by the anchor point and the reference surface. The surface of the T-slot connecting block 805a has precise graduations processed by laser etching, with a graduation interval of 0.1 mm and a graduation range of 0-20 mm. Using this structure, the spacing of the multilayer film can be precisely adjusted within the range of 0-20 mm to meet the installation requirements of different film tensions and flatness. In addition, a flange module 806 is also provided on the upper frame of the aluminum alloy square tube 802 on one side of the equilateral triangular end face frame 8. The flange module 806 consists of a flange 806a, a connecting plate 806b, and a first aluminum alloy square tube clamp 806c and a second aluminum alloy square tube clamp 806d. The structure of the first aluminum alloy square tube clamp 806c and the second aluminum alloy square tube clamp 806d is similar to the fixing method of the film gap adjuster 805 and the aluminum alloy square tube 802. They are also fixedly connected by clamping the aluminum alloy square tube 802 with two rectangular groove structures using screws. The connecting plate 806b is used to connect the flange structure to the second aluminum alloy square tube clamp 806d. The flange 806a is a standard round shaft connector used to connect with the intermediate connecting rod 5. Synchronous one-dimensional extension movement between the upper extension mechanism 2 and the lower extension mechanism 3 is achieved through the intermediate connecting rod 5.

[0015] For a single folding triangular prism mechanism, the motion process from the folded state to the unfolded state is as follows: Figure 7 and Figure 8 As shown. A single folding triangular prism mechanism is composed of a pair of opposing folding triangular prism unfolding and retracting units. The unfolding and retracting process of this mechanism is achieved through the cooperation of unfolding rope 9 and retracting rope 10. To more clearly illustrate the rope layout, [the following is a diagram / illustration]. Figure 7 The following is an example of a configuration where two units are fully deployed.Figure 7 As shown, for a folding triangular prism mechanism consisting of two triangular prism unfolding and retracting units, the unfolding rope 9 is led out from the rear side of the left equilateral triangular connecting frame 8, passes through the guide wheel 804, and first runs along the rectangular diagonal of the rear side of the left triangular prism unfolding and retracting unit. It reaches the middle equilateral triangular connecting frame 8, and then passes through the guide wheel 804 there to enter the front side of the triangular prism unfolding and retracting unit. It then runs along the rectangular diagonal of this side to the lower guide wheel 804 of the left equilateral triangular connecting frame 8. It then passes through the pulley to enter the bottom surface of the triangular prism unfolding and retracting unit, and runs along the rectangular diagonal of the bottom surface to the guide wheel 804 on the rear side of the middle equilateral triangular connecting frame 8. At this point, the deployment rope 9 has completed its layout in a triangular prism deployment unit and is arranged along the diagonals of the three sides of the triangular prism deployment unit. The deployment rope 9 then passes through the guide wheel 804 at the rear of the middle equilateral triangular frame 8 and enters the right triangular prism deployment unit. It is arranged along the diagonals of the three rectangular sides of the right triangular prism deployment unit in the same manner as the walking method described above. Finally, it is input from the rope output end to the next triangular prism deployment unit via the guide wheel 804 on the rightmost triangular prism connecting frame 8. Regarding the arrangement of the gathering rope 10, such as Figure 7 As shown, its arrangement is similar to that of the aforementioned unfolding rope 9. Similarly, it enters the left triangular prism unfolding / retracting unit via the guide wheel 804 of the leftmost equilateral triangular connecting frame 8, and then proceeds sequentially along the three diagonals of the three rectangular sides of the left triangular prism unfolding / retracting unit, which are different from the diagonals of the unfolding rope 9. That is, the unfolding rope 9 and the retracting rope 10 are arranged together along the six diagonal sides of the left triangular prism unfolding / retracting unit. Likewise, after the retracting rope 10 completes its arrangement in the left triangular prism unfolding / retracting unit, it enters the right triangular prism unfolding / retracting unit via the guide wheel 804 of the middle equilateral triangular connecting frame 8, and proceeds along the three diagonal sides of the right triangular prism unfolding / retracting unit in a similar arrangement to the left triangular prism unfolding / retracting unit. Finally, it enters the next unit via the guide wheel 804 on the rightmost equilateral triangular connecting frame 8. When fully folded, as Figure 8 As shown, the angle between the three connecting rods 7 in the left triangular prism unfolding / folding unit and the left equilateral triangular connecting frame 8 and the middle triangular connecting frame 8 is 0°. Simultaneously, the angle between the three connecting rods 7 in the right triangular prism unfolding / folding unit and the middle equilateral triangular connecting frame 8 and the right equilateral triangular connecting frame 8 is also 0°. At this time, the unfolding / folding unit is in a fully folded state, and the mechanism has its minimum lateral dimension when folded. However, when the mechanism needs to be unfolded, the unfolding rope 9 is tensioned and the folding rope 10 is relaxed. Under these operations, the diagonal lengths of the unfolding rope 9 are shortened, while the diagonal lengths of the folding rope 10 are increased. As the unfolding rope 9 is tensioned and the folding rope 10 is relaxed, the unfolding / folding unit will... Figure 8 The fully retracted state unfolds to Figure 6The intermediate transition state, until it is fully unfolded into Figure 7 The state; Expand to Figure 7 When fully extended, the three connecting rods 7 form the three sides of a regular triangular prism, creating a stable and regular prism structure. At this point, by simultaneously tensioning the unfolding rope 9 and the retracting rope 10, the joint gaps in the middle of the structural kinematic pairs can be effectively reduced, and the antagonistic effect of the tensioning of the two ropes can effectively improve the stiffness of the triangular prism unit, forming a stable support structure. For a single folding triangular prism mechanism, its unfolding and retracting motion has 1 degree of freedom. This is achieved by splicing together a pair of opposing folding triangular prism units. Figure 6 In the illustrated unfolding and retracting unit structure, to ensure synchronous movement between different folded triangular prism unfolding and retracting units, any two different folded triangular prism unfolding and retracting units are connected by... Figure 7 The three intersecting synchronous ropes 11 at the equilateral triangle connecting frame 8 are connected by a cross rope transmission layout to ensure that all folded triangular prism units move synchronously. This structural unit enables the unfolding and retraction of large rectangular films by modular one-dimensional extension in one direction. Figure 4 This demonstrates a one-sided one-dimensional unfolding unit 12 formed by modularly extended triangular prism unfolding and retracting units. Adjacent triangular prism unfolding and retracting units in unfolding unit 12 are connected by... Figure 10 The symmetrical triangle connecting frame 8 has cross-shaped synchronous ropes 11 on both sides connecting its corresponding parts, ensuring that all folded triangular prism mechanism units on one side have synchronous movement and share the same degree of freedom of motion. Figure 4 and Figure 5 The images show the fully retracted and fully extended states of the unfolding unit 12. When retracted, the units are stacked tightly, and when unfolded, they form a long strip-shaped prism array with good longitudinal extension capability. To achieve the goal of Figure 1 The unfolding and retraction operations of the large rectangular thin film structure described in the text, such as Figure 2As shown, the upper extension mechanism 2 and the lower extension mechanism 3 are placed in parallel and mechanically coupled at their ends by multiple intermediate connecting rods 5, forming a symmetrical double-sided unfolding system. Any two opposing equilateral triangular connecting frames 8 are connected by intermediate connecting rods 5, ensuring the overall coordinated movement of the two side structures and maintaining a system overall degree of freedom of 1. Both ends of the intermediate connecting rods 5 are connected by flange modules 806 on the equilateral triangular connecting frames 8. Side carbon fiber baffles 4 are installed on the left and right sides of the upper extension mechanism 2 and the lower extension mechanism 3 as load-bearing beams to enhance overall bending stiffness. These baffles are machined with circular perforated film spacing adjuster interfaces 14 for installing film spacing adjusters 805 in the lateral direction. Each equilateral triangular connecting frame 8 of the folding triangular prism unfolding mechanism unit in the upper extension mechanism 2 and the lower extension mechanism 3 is equipped with a film spacing adjuster 805. These film spacing adjusters 805 are used together to connect to the catenary 6 via a catenary connector 807 to adjust the spacing of the multi-layer films.

[0016] Specific implementation method three: Combining Figures 16 to 20 This embodiment is a further limitation of the first specific embodiment. The drive module 13 includes a box structure composed of an aluminum square frame 15 and a side plate 16. The box structure is equipped with an unfolding rope reel assembly and a retracting rope reel assembly. Multiple connecting blocks 22 for connecting to the unfolding unit 12 are respectively installed at both ends of the box structure. The unfolding rope reel assembly has two unfolding ropes 9 wound around it, and each unfolding rope 9 in the unfolding rope reel assembly corresponds to one unfolding unit 12. The retracting rope reel assembly has two retracting ropes 10 wound around it, and each retracting rope 10 in the retracting rope reel assembly corresponds to one unfolding unit 12. The unfolding rope reel assembly and the retracting rope reel assembly control the two unfolding units 12 to unfold synchronously through the two unfolding ropes 9 and the two retracting ropes 10. Other components and connection methods are the same as in specific embodiment one.

[0017] In this embodiment, the housing structure of the drive module 13 is composed of an aluminum square frame 15 and side plates 16. The aluminum square frame 15 is made of aerospace hard aluminum square tube. The left and right sides of the aluminum square frame 15 are processed with through holes near the opening of the square tube. These holes are used to connect the aluminum square frame 15 with the threaded holes on the two side plates 16 through bolts, so as to fix the aluminum square frame 15 with the front and rear side plates 16 together to form a cubic box-shaped component. Three connecting blocks 22 are provided on the outer side of the side plate 16. The three connecting blocks 22 are corresponding to the three connecting nodes 803 on the innermost equilateral triangular connecting frame 8 of each unfolding unit 12. Each connecting block 22 is machined with a threaded hole structure for connecting and fixing with the corresponding connecting node 803 by screws. As mentioned above, the unfolding and retraction operation of the overall unfoldable structure is realized by the cooperation between the unfolding rope 9 and the retracting rope 10. The unfolding rope reel assembly and the retracting rope reel assembly included in the drive module 13 are mainly used to control the unfolding rope 9 and the retracting rope 10. The unfolding rope reel assembly includes two primary drive motors 17 for providing power and an unfolding rope reel assembly 19 for winding the unfolding rope. Each primary drive motor 17 has a primary pulley 171 mounted on its power output end. The primary pulley 171 is connected to one end of the unfolding rope reel assembly 19 via a synchronous belt 21. That is, during operation, the two primary drive motors 17 synchronously output power to drive the unfolding rope reel assembly 19 to rotate. Two unfolding ropes 9 are wound on the unfolding rope reel assembly 19, and the two unfolding ropes 9 rotate in opposite directions. When the two primary drive motors 17 work at the same time, the two unfolding ropes 9 are released synchronously and drive the corresponding unfolding unit 12 to unfold freely and synchronously. The coiling rope reel assembly includes two secondary drive motors 18 for providing power and a coiling rope reel assembly 20 for winding the coiling rope. Each secondary drive motor 18 has a secondary pulley 181 mounted on its power output end. The secondary pulley 181 is connected to one end of the coiling rope reel assembly 20 via a synchronous belt 21. That is, during operation, the two secondary drive motors 18 synchronously output power to drive the coiling rope reel assembly 20 to rotate. Two coiling ropes 10 are wound on the coiling rope reel assembly 20, and the two coiling ropes 10 have opposite rotation directions. When the two secondary drive motors 18 work at the same time, the two coiling ropes 10 are released synchronously and drive the corresponding unfolding unit 12 to unfold freely and synchronously. The unfolding rope reel assembly 19 and the taking-up rope reel assembly 20 in this embodiment have the same composition structure. The following describes the structural details of the reel assembly using the unfolding rope reel assembly 19 as an example. The unfolding rope reel assembly 19 includes an unfolding rope reel 1902. A reel pulley 1901 is installed at each end of the unfolding rope reel 1902. The reel pulley 1901 is connected to the first pulley 171 via a synchronous belt 21. The housing of the first drive motor 17 is fixedly connected to the side plate 16. The outer circular surface of the reel pulley 1901 is machined with a double-rotating spiral groove structure to accommodate the unfolding rope 9 and ensure accurate release of the unfolding rope 9 during transmission. The two groove structures with forward and reverse rotation on the unfolding rope reel 1902 are used to drive the unfolding rope 9 in the unfolding unit 12 located on both sides of the drive module 13 to be released. This ensures that the unfolding units 12 on the left and right sides of the drive module 13 move synchronously. The central part of the unwinding rope reel 1902 is a hollow cylindrical structure with a central sleeve coaxially mounted therein. A keyway is machined on the inner wall of the end of the central sleeve. The central sleeve is supported and fixed to the support frame of the unwinding rope reel 1902 by multiple support arms. A gear-connecting threaded hole is machined on the outermost support arm. The pulleys 1901 at both ends of the unwinding rope reel 1902 are fastened to the support arms on the unwinding rope reel 1902 by bolts. A drive shaft 1904 is inserted into the central sleeve. A second keyway, which mates with the first keyway, is machined on the drive shaft 1904. The drive shaft 1904 is connected to the central sleeve by a key. Both ends of the drive shaft 1904 extend out of the central sleeve and pass through the corresponding side plate 16 to the outside of the housing structure. Each end of the drive shaft 1904 is fitted with an end cover bearing seat 1903 and is rotatably connected to the end cover bearing seat 1903 by bearing 19031. The end cover bearing seat 1903 is machined with bearing seat fixing holes. The end cover bearing seat 1903 is fixedly connected to the side plate 16 by bolts. Two bushings 1905 are also fitted on both ends of the central sleeve to ensure the accuracy of the installation position of the central sleeve.

[0018] This application has disclosed the preferred embodiments above, but it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed structures and technical contents to create equivalent embodiments without departing from the scope of the present invention. However, any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the content of the present invention shall still fall within the scope of the present invention.

Claims

1. A large-scale spatial thin-film unfolding structure based on folded triangular prism mechanism units with adjustable spacing, characterized in that: The spatial membrane unfolding structure includes a folded triangular prism extension device. A side carbon fiber baffle (4) is installed at each end of the folded triangular prism extension device. The membrane (1) is set in the extension frame composed of the folded triangular prism extension device and the two side carbon fiber baffles (4), and is fixedly connected to the extension frame by multiple catenary wires (6). The folded triangular prism extension device serves as a power source to drive the membrane (1) to extend or contract synchronously with the extension frame.

2. The adjustable-spacing large-scale spatial thin-film unfolding structure based on folded triangular prism mechanism units according to claim 1, characterized in that: The folding triangular prism extension device includes an upper extension mechanism (2) and a lower extension mechanism (3). The upper extension mechanism (2) and the lower extension mechanism (3) are arranged in parallel opposite directions. The two ends of the upper extension mechanism (2) and the two ends of the lower extension mechanism (3) are respectively fixedly connected to the corresponding side carbon fiber baffles (4).

3. The adjustable-spacing large-scale spatial thin-film unfolding structure based on folded triangular prism mechanism units according to claim 2, characterized in that: The upper extension mechanism (2) and the lower extension mechanism (3) have the same structure. Multiple intermediate connecting rods (5) are provided at equal intervals along the extension direction of the extension frame between the upper extension mechanism (2) and the lower extension mechanism (3). The two ends of each intermediate connecting rod (5) are detached and connected to the corresponding upper extension mechanism (2) or lower extension mechanism (3). The upper extension mechanism (2) and the lower extension mechanism (3) are mechanically coupled through multiple intermediate connecting rods (5) to form a double-sided unfolding system.

4. The adjustable-spacing large-scale spatial thin-film unfolding structure based on folded triangular prism mechanism units according to claim 3, characterized in that: The upper extension mechanism (2) includes a drive module (13), and an extension unit (12) is installed on each side of the drive module (13). The drive module (13) acts as a power source to drive the two extension units (12) to extend or retract synchronously.

5. The adjustable-spacing large-scale spatial thin-film unfolding structure based on folded triangular prism mechanism units according to claim 4, characterized in that: The unfolding unit (12) includes N linkage components and N+1 equilateral triangular connecting frames (8), where N is a positive integer. The N+1 equilateral triangular connecting frames (8) are arranged equidistantly on one side of the drive module (13) along the extension direction of the extension frame. A linkage component is provided between two adjacent equilateral triangular connecting frames (8). One end of each linkage component is hinged to the adjacent equilateral triangular connecting frame (8). Two adjacent linkage components are connected by multiple synchronous ropes (10). The linkage component and two adjacent equilateral triangular connecting frames (8) form a triangular prism unfolding and retracting unit. Two adjacent triangular prism unfolding and retracting units that fold in opposite directions form a folding triangular prism mechanism.

6. The adjustable-spacing large-scale spatial thin-film unfolding structure based on folded triangular prism mechanism units according to claim 5, characterized in that: The linkage assembly includes three links (7), which are arranged parallel to each other between two adjacent equilateral triangular connecting frames (8). The two ends of each link (7) are respectively hinged to the corresponding equilateral triangular connecting frame (8), and the two links (7) arranged coaxially in two adjacent linkage assemblies are connected by a synchronous rope (11).

7. A large-scale spatial thin-film unfolding structure based on a folded triangular prism mechanism unit with adjustable spacing, as described in claim 6, is characterized in that: The equilateral triangle connecting frame (8) includes an aluminum alloy square tube (802), two carbon fiber rods (801) and three connecting joints (803). The aluminum alloy square tube (802) and the two carbon fiber rods (801) are arranged in an equilateral triangle. The two ends of the aluminum alloy square tube (802) are connected to the corresponding carbon fiber rods (801) through a connecting joint (803). The two carbon fiber rods (801) are connected through a connecting joint (803). The aluminum alloy square tube (802) is equipped with a multi-layer film spacing adjuster (805) for connecting the catenary (6) and a flange module (806) for connecting the intermediate connecting rod (5).

8. A large-scale spatial thin-film unfolding structure based on a folded triangular prism mechanism unit with adjustable spacing, as described in claim 7, is characterized in that: The multilayer film spacing adjuster (805) is connected to the catenary (6) via the catenary connector (807).

9. A large-scale spatial thin-film unfolding structure based on a folded triangular prism mechanism unit with adjustable spacing, as described in claim 8, is characterized in that: The drive module (13) includes a box structure consisting of an aluminum frame (15) and a side plate (16). The box structure is equipped with an unfolding rope reel assembly and a retracting rope reel assembly. Multiple connecting blocks (22) for connecting to the unfolding unit (12) are installed at both ends of the box structure.

10. A large-scale spatial thin-film unfolding structure based on a folded triangular prism mechanism unit with adjustable spacing, as described in claim 9, is characterized in that: Two unfolding ropes (9) are wound on the unfolding rope reel assembly, and each unfolding rope (9) in the unfolding rope reel assembly corresponds to one unfolding unit (12). Two gathering ropes (10) are wound on the gathering rope reel assembly, and each gathering rope (10) in the gathering rope reel assembly corresponds to one unfolding unit (12). The unfolding rope reel assembly and the gathering rope reel assembly control the two unfolding units (12) to perform unfolding actions synchronously through the two unfolding ropes (9) and the two gathering ropes (10).

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