Large-size flat film structure orderly folding storage tooling and film folding method

Abstract

The present invention discloses a tool for orderly folding and storing large-scale planar film structures and a film folding method. The folding and storing tool comprises a tool structure support frame, auxiliary support rods on the outer sides of the film, a guide device, a pulling device, and a crease structure plate. The crease structure plate is used to fold the film by inserting the film into crease holes provided on the lower and upper film support plates. The present invention achieves the crease structure of the large-scale planar film by sequentially inserting all the crease structure plates, and then completes the folding and compacting of the large-scale planar film by sequentially removing the upper film support plate and the crease structure plate. This solves the problem of difficulty in folding large-scale film structures and maintaining their position during folding.

Description

Technical Field

[0001] The present invention belongs to the technical field of large-scale film processing tooling, and specifically relates to a design method for large-scale flat film folding auxiliary tooling, which can be used for auxiliary folding of large-scale polymer material film structures. Background Art

[0002] Polymer film structures have the advantages of light weight, high strength and low cost, and are widely used in large-scale space deployable structures in aerospace. In order to facilitate the unfolding and transportation of large-scale flat film structures, large-scale film structures generally need to be reduced in volume by winding or folding.

[0003] By rationally designing the folding mechanism for large-scale, planar membrane structures, it is possible to achieve smooth, tear-free unfolding of these structures, ensuring the structural and functional integrity of the membrane. Common large-scale membrane structures have an envelope diameter exceeding 1 meter and a storage ratio exceeding 5, requiring complex crease design and distribution. Due to the strength and flatness requirements of the membrane structure, creases cannot be created on the surface of large-scale polymer membrane structures through cutting or bending.

[0004] The existing crease construction of large-scale planar film structures in space usually adopts the form of scoring the film surface or gluing a backplane, and the film crease construction is achieved by creating differences in the thickness direction of the film. The method of scoring the film surface will affect the strength of the film structure and is not suitable for scenarios that require large tension or high requirements on the thickness of the film surface. The method of gluing the backplane will affect the weight and stiffness characteristics of the film structure, which has a more obvious negative impact on large-scale films. Large-scale films have larger geometric dimensions and more crease designs, so more backplanes are needed to construct creases, which is not conducive to improving structural reliability and reducing emission quality and assembly process complexity. Summary of the Invention

[0005] This paper presents a design method for orderly folding and storage of large-scale planar membrane structures. For large-scale membrane structures with high storage ratios, orderly folding and storage is an important means to achieve smooth membrane unfolding and avoid tearing during the unfolding process.

[0006] A tooling for orderly folding and storing large-scale flat film structures, comprising: a tooling structure support frame, a film support plate group, including a lower film support plate and an upper film support plate; the film is located between the lower film support plate and the upper film support plate of the film support plate group, and the inner end of the film is fixed to the inner end of the film support plate group; the lower film support plate and the upper film support plate are provided with crease holes designed according to the film crease; an auxiliary support rod on the outer side of the film is used to fix the outer end of the film; a guide device is connected to the auxiliary support rod on the outer side of the film to move the auxiliary support rod on the outer side of the film in the folding direction; a pulling device is connected to the guide device to apply a flattening pulling force to the film to be folded; a crease structure plate is used to fold the film by folding the film into the crease holes provided on the lower film support plate and the upper film support plate.

[0007] The guide device includes a slider and a slide rail, the slider is arranged on the slide rail; the slide rail is fixed on the tooling structure support frame; the auxiliary support rod outside the film is arranged on the slider.

[0008] A support rod connecting plate is provided on the sliding block; the auxiliary support rod outside the film is fixed on the support rod connecting plate.

[0009] The pulling device includes a fixed pulley, a traction rope and a weight block; one end of the traction rope is connected to the slider, and the other end of the traction rope is connected to the weight block.

[0010] The crease holes in the lower support plate and the upper support plate of the film are opened according to the crease position when the annular film is folded 50% radially inward. The upper support plate of the film is opened with reference to the peak crease, and the lower support plate of the film is opened with reference to the valley crease. Among them, the Miura crease hole opening shape is "V" shaped, and the opening angle and opening length refer to the peak crease of the innermost circle Miura crease. The Z-shaped crease hole opening shape is "I" shaped, and the opening length is designed according to the length of the peak crease and valley crease corresponding to the position of each circle of crease in the 50% folded state.

[0011] The fixture support frame provides structural support for the large-scale flat film folding auxiliary tooling. The lower and upper film support plates, slide rails, and fixed pulleys are mounted on the frame. The frame is constructed from 4040 aluminum alloy profiles. The frame's total height is approximately 1.4 meters, ensuring the lower film support plate is at least 1.2 meters above the ground. The upper film support plate is suspended from the frame to prevent the tooling from interfering with the film folding process. A handrail is provided above the frame to allow for the installation of the crease plate onto the upper film support plate.

[0012] The film is fixed to the inner edge of the support plate under the film and the auxiliary support rod on the outside of the film. The auxiliary support rod on the outside of the film is connected to the support rod connecting plate and the slider. The support rod connecting plate is connected to the weight block through a nylon rope passing around the fixed pulley, so that the auxiliary support rod on the outside of the film moves along the slide rail under the action of the gravity of the weight block, providing an outward flattening force for the film.

[0013] The lower and upper membrane support plates feature crease holes designed to align with the membrane's creases. By sequentially inserting crease plates into these holes, the orderly crease formation of large-scale planar membrane structures can be achieved. Both plates are made of polymer and feature weight-reducing holes on their surfaces. Mounting holes for the detachable magnetic blocks of the crease plates are located on either side of the crease holes and are used to mount magnetic material.

[0014] The creased structural plate is made of polymer material. A handle is provided on one side of the creased structural plate to facilitate the installation and disassembly of the creased structural plate. Removable magnetic blocks are designed at both ends of the handle side of the creased structural plate. The installation of the creased structural plate is completed through the magnetic force between the magnetic materials in the creased holes of the lower support plate and the upper support plate of the film.

[0015] The membrane's outer auxiliary support rods mirror the outer edge of the film and consist of six Z-fold rods and 24 Miura fold rods. These rods are connected by hinges composed of bolts and bearings. The six Z-fold rods are 700 mm long, constraining the membrane's fold design. The 24 Miura fold rods are installed in groups of four on each side of the membrane's outer hexagonal shape, with their lengths equal to one-fourth the length of the hexagonal side. During the membrane fold construction process, the outer auxiliary support rods, pulled outward along the slide rails by a weight, flatten the film. When the membrane construction plate is inserted into the lower and upper support plates, the outer auxiliary support rods move inward due to the crease. The outer auxiliary support rods are manually folded radially inward along the membrane according to the membrane fold design, completing the movement and folding of the outer auxiliary support rods along the slide rails and the shape of the membrane's outer edge.

[0016] Since the film folds are Miura folds and Z-shaped folds alternately connected along the circumferential direction, during the film fold construction process, the six Z-fold area rods drive the films at their respective positions to fold in a radial Z shape, and the four Miura fold area rods on each side of the hexagonal outer ring of the film are folded in a "W" shape. After folding with the Miura fold, the central ridge protrudes radially outward while storing the outer film.

[0017] The auxiliary support rod on the outside of the film, the support rod connecting plate and the slider are connected by bolts to achieve the shape-keeping and flattening capabilities of the auxiliary support rod on the outside of the film on the outer edge of the film.

[0018] The mass of the weight block is recommended to be 0.1kg~0.5kg based on the simulation and test results of the flattening force during the film unfolding process.

[0019] The large-scale flat film folding auxiliary tooling is used to construct the creases of a large-scale flat film structure. This film has the following characteristics: a hexagonal annular film structure is used. The inner hexagon of the annular film structure is rotated 30 degrees clockwise relative to the outer hexagon. The creases within the annular film are composed of Miura folds and Z-shaped folds alternating along the circumference. Crease holes in the lower and upper film support plates, along with the crease construction plates, are designed based on the crease positions when the annular film is folded 50% radially inward. The upper film support plate is designed with reference to the peak crease, while the lower film support plate is designed with reference to the valley crease. The Miura crease holes are V-shaped, with the angle and length of the holes being based on the peak crease of the innermost Miura crease. The Z-shaped crease holes are U-shaped, with the length of the holes designed based on the peak and valley crease lengths of each crease at the 50% folded position.

[0020] The crease plate must be matched to the crease holes of the upper and lower membrane support plates. Miura crease plates are uniform in shape and length, while the length of Z-crease plates must be individually designed to match the installation location.

[0021] The process of folding a large-scale flat film structure: First, the inner edge of the large-scale flat film structure is glued and fixed to the inner edge of the lower support plate of the film, and the outer edge of the large-scale flat film structure is glued and fixed to the surface of the auxiliary support rod. Under the gravity of the weight block, the auxiliary support rod moves along the slide rail to the outside of the annular film to flatten the film structure. Then, when the film folding begins, the Z-shaped folding structural plate and the Miura folding structural plate of the innermost peak fold of the annular film are inserted upward from the lower support plate of the film, and then the Z-shaped folding structural plate and the Miura folding structural plate of the corresponding position are inserted from the inside to the outside of the annular film structure above the upper support plate and below the lower support plate of the film. After each circle of folding structural plates is inserted, the film structure needs to be sorted until all the folding construction work is completed.

[0022] After completing the folding of the large-scale flat membrane structure, the Z-shaped folding plates and Miura folding plates attached to the upper and lower membrane support plates need to be removed one by one, starting from the outside of the annular membrane structure and moving inward. Each time a circle of folding plates is removed, the folds in that circle need to be adjusted and the auxiliary support rods on the outer side of the membrane need to be folded inward to compact the pre-folded membrane structure. After all folds are compacted, the large-scale flat membrane structure can be folded by removing the upper membrane support plate.

[0023] The crease plate must be designed to match the crease holes in the upper and lower membrane support plates. The Miura crease hole opening is V-shaped, with the opening angle and length referenced to the innermost Miura crease peak. Therefore, the shape and length of the Miura crease plate are uniform. The Z-shaped crease hole opening is I-shaped, with the opening length designed based on the peak and valley crease lengths of each crease at a 50% fold. Therefore, the length of the Z-shaped crease plate must be tailored to the installation location.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] By using large-scale flat folding auxiliary tooling, the film structure tensioning work, film structure crease construction work, and film structure folding and pressing work can be carried out sequentially, which greatly reduces the difficulty and cost of large-scale film structure crease construction, improves the accuracy of crease construction position, and improves the efficiency of large-scale flat film structure crease construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic diagram of the tooling structure for orderly folding and storing large-scale flat membrane structures.

[0027] Figure 2 A partial side view of a tool for orderly folding and storing a large-scale flat membrane structure.

[0028] Figure 3 This is a schematic diagram of the partial structure of the tooling for orderly folding and storing large-scale flat membrane structures.

[0029] Figure 4 This is a partial schematic diagram of the stretching and flattening mechanism of the large-scale flat film structure orderly folding and storage tooling.

[0030] Figure 5 Schematic diagram of the auxiliary support rods on the outer side of the film for orderly folding and storage of large-scale flat film structures

[0031] Figure 6 Schematic diagram of the folding of the auxiliary support rods on the outer side of the film for orderly folding and storage of large-scale flat film structures

[0032] Figure 7 This is a schematic diagram of the support plate structure for the film of the large-scale flat film structure that is folded and stored in an orderly manner.

[0033] Figure 8 This is a schematic diagram of the Z-shaped folded structural plate structure of a large-scale flat membrane structure with orderly folding and storage tooling.

[0034] Figure 9 Schematic diagram of the Miura crease structural plate structure for the orderly folding and storage tooling of large-scale flat membrane structures. DETAILED DESCRIPTION

[0035] The present invention provides a design method for orderly folding and storing tooling for large-scale planar film structures. For large-scale film structures with high storage ratios, orderly folding and storing is an important means to achieve smooth film unfolding and avoid film tearing during unfolding.

[0036] The present invention is aimed at a tool for orderly folding and storing large-scale flat film structures, including a tool structure support frame 1, a lower film support plate 2, an upper film support plate 3, a Z-shaped fold structural plate 4, an auxiliary support rod 5 on the outer side of the film, a support rod connecting plate 6, a fixed pulley 7, a slider 8, a slide rail 9, a weight block 10 and a Miura fold structural plate 11.

[0037] The tooling structure support frame 1 is used to provide structural support for the auxiliary tooling for large-scale flat film folding. The lower film support plate 2, the upper film support plate 3, the fixed pulley 7 and the slide rail 9 are installed on the tooling structure support frame 1. The tooling structure support frame 1 is composed of 4040 aluminum alloy profiles. The total height of the tooling structure support frame 1 is approximately 1.4m, ensuring that the lower film support plate 2 is greater than 1.2m above the ground. The upper film support plate 3 is installed on the tooling structure support frame 1 in a hanging manner to avoid the influence of the tooling on the film folding process. Above the tooling structure support frame 1, there is reserved hand operation space for installing the Z-shaped folding structural plate 4 and the Miura folding structural plate 11 from above the upper film support plate 3.

[0038] The film is fixed to the inner edge of the support plate 2 under the film and the auxiliary support rod 5 on the outside of the film. The auxiliary support rod 5 on the outside of the film is connected to the support rod connecting plate 6 and the slider 8. The support rod connecting plate 6 is connected to the weight block 10 through a nylon rope passing around the fixed pulley 7, so that the auxiliary support rod 5 on the outside of the film can move along the slide rail 9 under the action of the gravity of the weight block 10, providing an outward flattening force for the film.

[0039] The lower and upper film support plates 2 and 3 are provided with crease holes 12 designed to align with the film's crease pattern. By sequentially inserting the Z-shaped crease plate 4 and the Miura crease plate 11 into these crease holes 12, an orderly crease pattern can be achieved for a large, planar film structure. The lower and upper film support plates 2 and 3 are constructed of a polymer material and feature weight-reducing holes 13 on their surfaces. Mounting holes 15, designed to match the removable magnetic blocks 14 on the Z-shaped and Miura crease plates 4 and 11, are located on either side of the crease holes 12 and are used to mount magnetic material.

[0040] The Z-shaped fold structural plate 4 and the Miura fold structural plate 11 are made of polymer material, and a handle is provided on one side of the Z-shaped fold structural plate 4 and the Miura fold structural plate 11 to facilitate the installation and disassembly of the Z-shaped fold structural plate 4 and the Miura fold structural plate 11. Removable magnetic blocks 14 are designed at both ends of the handle side of the Z-shaped fold structural plate 4 and the Miura fold structural plate 11, and the installation of the Z-shaped fold structural plate 4 and the Miura fold structural plate 11 is completed by the magnetic force between the magnetic material in the fold hole of the lower support plate 2 and the upper support plate 3 of the film.

[0041] The outer shape of the auxiliary support rod 5 on the outer side of the film is the same as the shape of the outer edge of the film. The auxiliary support rod 5 on the outside of the film is composed of 6 Z-fold area rods 16 and 24 Miura fold area rods 17, and the rods are connected by hinges composed of bolts and bearings; the 24 Miura fold area rods 17 are installed in groups of 4 on each side of the hexagon of the outer ring of the film, and their length is 4 equal parts of the side length of the hexagon of the outer ring of the film; one Z-fold area rod 16 is set on each slider, and one group of Miura fold area rods 17 is hinged between two adjacent Z-fold area rods 16; during the film folding construction process, the auxiliary support rod 5 on the outside of the film is pulled outward along the slide rail 9 by the traction of the weight block 8, and when the Z-fold structural plate 4 and the Miura fold structural plate 11 are inserted into the lower support plate 2 and the upper support plate 3 of the film, the auxiliary support rod 5 on the outside of the film moves inward due to the formation of the fold, and the auxiliary support rod 5 on the outside of the film is manually folded inward along the radial direction of the film according to the film fold design, and the movement and folding of the auxiliary support rod 5 on the outside of the film along the slide rail 9 and the outer edge shape of the film are completed.

[0042] Since the film folds are Miura folds and Z-shaped folds alternately connected along the circumferential direction, during the film fold construction process, the six Z-fold area rods drive the films at their respective positions to fold in a radial Z shape, and the four Miura fold area rods on each side of the hexagonal outer ring of the film are folded in a "W" shape. After folding with the Miura fold, the central ridge protrudes radially outward while storing the outer film.

[0043] The auxiliary support rod 5 on the outer side of the film, the support rod connecting plate 6 and the slider 8 are connected by bolts to achieve the shape-keeping and flattening capabilities of the auxiliary support rod 5 on the outer side of the film.

[0044] The mass of the weight block 10 is based on the simulation and test results of the flattening force during the film unfolding process, and a recommended value is 0.1kg~0.5kg.

[0045] The large-scale flat film folding auxiliary tooling is used in the crease construction process of a large-scale flat film structure. This type of film has the following characteristics: a hexagonal annular film structure is used, with the inner hexagon rotated 30° clockwise relative to the outer hexagon. The creases within the annular film are composed of Miura folds and Z-shaped folds alternating along the circumference. Crease holes 12 formed in the film's lower and upper support plates 2 and 3, along with the Z-shaped fold construction plates 4 and Miura fold construction plates 11, are formed according to the fold positions when the annular film is folded 50% inward in the radial direction. The holes in the upper support plate 3 are formed according to the peak folds, while the holes in the lower support plate 2 are formed according to the valley folds. The Miura fold holes are V-shaped, with the opening angle and length referenced to the peak fold of the innermost Miura fold. The Z-shaped fold holes are U-shaped, with the opening length designed based on the peak and valley fold lengths of each fold at the corresponding locations of the film when the film is folded 50% inward.

[0046] The Z-shaped folded structural plate 4 and the Miura folded structural plate 11 need to be matched with the folded holes 12 of the upper film support plate 3 and the lower film support plate 2. The shape and length of the Miura folded structural plate 11 are uniform, while the length of the Z-shaped folded structural plate 4 needs to be designed individually to match the folded holes 12 at the installation location.

[0047] The process of folding a large-scale flat film structure: First, fix the large-scale flat film structure on the surface of the film's lower support plate 2 and the auxiliary support rod 5 on the outside of the film, and flatten the film structure under the gravity of the weight block 10. When starting to fold the film, first insert the Z-shaped fold structural plate 4 and the Miura fold structural plate 11 of the innermost peak fold of the ring upward below the film's lower support plate 2, then install the Z-shaped fold structural plate 4 and the Miura fold structural plate 11 of the next circle of valley folds, and then install the Z-shaped fold structural plate 4 and the Miura fold structural plate 11 of the next circle of peak folds. Insert the Z-shaped fold structural plate 4 and the Miura fold structural plate 11 in the corresponding position above the film's upper support plate 3 and below the film's lower support plate 2 in turn until all the folding construction work is completed.

[0048] After completing the fold structure of the large-scale planar film structure, it is necessary to first remove the Z-shaped fold structural plate 4 and the Miura fold structural plate 11 of the circle valley fold from the outermost side of the annular film structure. After arranging this circle valley fold, use the auxiliary support rod 5 on the outside of the film to fold inward and compact the film structure of this circle valley fold. Then remove the Z-shaped fold structural plate 4 and the Miura fold structural plate 11 of the next circle peak fold inward. Similarly, after arranging this circle peak fold, use the auxiliary support rod 5 on the outside of the film to fold inward and compact the peak fold film structure of this circle fold. Then, remove the Z-shaped fold structural plate 4 and the Miura fold structural plate 11 circle by circle from the outside to the inside, and after removing each circle of the Z-shaped fold structural plate 4 and the Miura fold structural plate 11, arrange the circle fold and fold inward and compact the film structure of this circle fold through the auxiliary support rod 5 on the outside of the film. After completing the compaction of all the folds, the large-scale planar film structure can be folded by removing the upper support plate 3 of the film.

Claims

1. A tool for orderly folding and storing large-scale flat film structures, characterized in that: include: Tooling structure support frame; A film support plate group is provided on the tooling structure support frame, and the film support plate group includes a film lower support plate and a film upper support plate; The film is located between the lower film support plate and the upper film support plate of the film support plate group, and the inner end of the film is fixed to the inner end of the film support plate group; the lower film support plate and the upper film support plate are provided with crease holes designed according to the crease of the film; Auxiliary support rods on the outside of the film, used to fix the outer end of the film; A guide device is connected to the auxiliary support rod on the outer side of the film, so that the auxiliary support rod on the outer side of the film moves along the folding direction; a pulling device connected to the guide device, for applying a flattening pulling force to the film to be folded; The crease structure plate is used to insert into the crease holes provided on the lower support plate and the upper support plate of the film when the film is folded to fold the film; The guide device includes a slider and a slide rail, the slider is arranged on the slide rail; the slide rail is fixed to the tooling structure support frame; the auxiliary support rod outside the film is arranged on the slider; The pulling device includes a fixed pulley, a traction rope and a weight block; one end of the traction rope is connected to the slider, and the other end of the traction rope is connected to the weight block; The auxiliary support rods on the outside of the film are composed of 6 Z-fold area rods and 24 Miura fold area rods, and the rods are connected by hinges composed of bolts and bearings; the 24 Miura fold area rods are installed in groups of 4 on each side of the hexagon of the outer ring of the film, and their length is 4 equal parts of the side length of the hexagon of the outer ring of the film; one Z-fold area rod is set on each slider, and one group of Miura fold area rods is hinged between two adjacent Z-fold area rods; the film fold is a Miura fold and a Z-shaped fold alternately connected along the circumferential direction, and during the film fold construction process, the auxiliary support rods on the outside of the film are pulled outward along the slide rail under the traction of the weight block, and when the fold construction plate is inserted into the lower support plate and the upper support plate of the film, the auxiliary support rods on the outside of the film are driven inward by the formation of the fold, and the auxiliary support rods on the outside of the film are manually folded radially inward along the film according to the film fold design, so as to complete the movement and folding of the auxiliary support rods on the outside of the film along the slide rail and the shape of the outer edge of the film; The crease holes in the lower support plate and the upper support plate of the film are opened according to the crease position when the annular film is folded 50% radially inward. The upper support plate of the film is opened with reference to the peak crease, and the lower support plate of the film is opened with reference to the valley crease. Among them, the Miura crease hole has a "V" shape, and the opening angle and length are the same as the angle and length of the peak crease of the innermost circle Miura crease. The Z-shaped crease hole has a "I" shape, and the opening length is designed according to the length of the peak crease and valley crease at the corresponding position of each circle of crease in the 50% folded state.

2. The tooling for orderly folding and storing large-scale planar film structures according to claim 1, characterized in that: A support rod connecting plate is provided on the sliding block; the auxiliary support rod outside the film is fixed on the support rod connecting plate.

3. The tooling for orderly folding and storing large-scale planar film structures according to claim 1, characterized in that: Mounting holes that match the detachable magnetic blocks of the fold structural plate are provided on both sides of the fold hole and are used to mount magnetic materials.

4. The tooling for orderly folding and storing large-scale planar film structures according to claim 1, characterized in that: The outer shape of the auxiliary support rod on the outer side of the film is the same as the shape of the outer edge of the film.

5. A film folding method for orderly folding and storing a large-scale planar film structure according to any one of claims 1 to 4, characterized in that: The film to be folded is fixed between the film support plate group and the auxiliary support rod on the outside of the film; the fixed film to be folded is flattened by a pulling device; all the peak fold construction plates of the Miura folds and Z-shaped folds located on the innermost side of the ring are inserted upward under the lower support plate of the film, and then the fold construction plates of the Miura folds and Z-shaped folds at the corresponding positions are inserted circle by circle above the upper support plate of the film and below the lower support plate of the film until all the fold construction work is completed.

6. The film folding method according to claim 5, characterized in that: After completing the crease structure of the large-scale flat film structure, the crease structure plates installed on the upper support plate and the lower support plate of the film are removed one by one from the outer ring to the inner ring. Each time a circle of crease structure plates is removed, the creases of this circle are sorted and the pre-folded film structure is folded inward and compacted through the auxiliary support rods on the outside of the film; after completing the compaction of all the creases, the folding of the large-scale flat film structure can be completed by removing the upper support plate of the film.

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