3D printing-based manufacturing process for Kreshing type paper folding structure

Abstract

The invention provides a manufacturing process of a Kresling type paper folding structure based on 3D printing. The process comprises a paper folding part manufacturing process, an upper cover part and lower cover part manufacturing process, a sealing gasket manufacturing process and a paper folding type structure splicing process. The manufacturing process comprises the steps of model building, 3D printing and follow-up treatment. Material selection, parameter setting and matters needing attention in the steps are introduced in detail. The splicing process comprises the steps of positioning, sealing and combining. The splicing method and matters needing attention are introduced in detail. According to the method, rapid forming of the Kresling origami structure is achieved through 3D printing, good flexibility and fatigue resistance are achieved, parameters can be changed in the process of establishing a model, and complex expansion design of the Kresling type structure is achieved.

Description

Technical Field

[0001] The present invention relates to the field of manufacturing origami robots, and particularly to a manufacturing process of Kresling - like origami structures based on 3D printing. Background Art

[0002] The Kresling origami structure is a three - dimensional geometric structure based on origami art. It is based on a hexagonal structure. By rotating, folding, and twisting the hexagon, a three - dimensional structure with high complexity and stability can be obtained. With its excellent foldability, high flexibility, high strength, and high load - bearing capacity, it has become a common structure in origami robots.

[0003] The Kresling - like origami structures designed based on the Kresling origami structure are widely used in fields such as aerospace, human - machine interaction, and special robots. The Kresling - like origami structure can be formed by laser - cutting an elastic film with dotted lines to form creases, and then completed by folding. This solution will cause certain plastic deformation and there are certain fatigue problems, and the complete self - recovery of the structure is still a problem. The Kresling - like origami structure can also be manufactured by completely cutting and then pasting, and then performing a sealing treatment. Although this solution can improve the fatigue strength of the Kresling - like origami structure compared to the first solution, the process is relatively complex and the manufacturing difficulty is large. Therefore, there is an urgent need for a new manufacturing process for Kresling - like origami structures in this field. Summary of the Invention

[0004] In order to solve the above - mentioned technical problems, the purpose of the present invention is to provide a manufacturing process of Kresling - like origami structures based on 3D printing. To achieve the above purpose, the present invention adopts the following solutions.

[0005] A manufacturing process of Kresling - like origami structures based on 3D printing, which includes the following steps:

[0006] S100. Modeling each part of the Kresling - like origami structure through three - dimensional modeling software to obtain 3D models of each part of the Kresling - like origami structure; the Kresling - like origami structure includes: an origami part, an upper cover part, a lower cover part, and a sealing gasket part; converting the 3D models of each part of the Kresling - like origami structure into files in a format supported by the 3D printer; setting the structural parameters and positioning structural parameters of each part according to the accuracy of the 3D printer used;

[0007] S200. Inputting the file, selecting the material for 3D printing and setting the printing parameters; selecting the printing base surface and setting the position of the support for printing to obtain each part structure of the Kresling - like origami structure;

[0008] S300. Post-process each part of the Kresling-like origami structure. Immerse each part in alcohol and then place it in an ultraviolet curing oven for curing. After curing, remove the supports to obtain the finished products of each part of the Kresling-like origami structure.

[0009] S400. Assemble the finished products of each part of the Kresling-like origami structure according to the assembly process to obtain the kersling-like origami structure.

[0010] In step S100, for the origami part, model the origami part using 3D modeling software. After the model is established, export it in STL file format for 3D printing.

[0011] In step S100, for the origami part, according to the accuracy of the 3D printer used, set the crease parameters and positioning structure parameters of the origami part. There are skirts on the upper side of the origami part that cooperate with the upper cover part, and skirts on the lower side of the origami part that cooperate with the lower cover part.

[0012] In step S200, for the origami part, use a stereolithography 3D printer, use 80A transparent resin as the printing material and set the printing parameters. Select the upper and lower bottom surfaces of the origami part as the printing bases, and set all the supports at the bottom. Only a small amount of supports are set at the newly designed structures on the basis of the Kresling origami structure inside the cavity, and all the supports grow from the bottom.

[0013] In step S300, for the origami part, immerse the whole printed origami part in alcohol for 10 minutes. After soaking, place the printed part in an ultraviolet curing oven and cure it under the condition of 60 °C for 10 min. After taking it out, remove the supports.

[0014] For the upper cover part and the lower cover part, in step S100, model the upper cover part and the lower cover part using 3D modeling software. There is an upper cover part groove inside the upper cover part, and an externally convex upper cover part cylindrical air hole outside; there is a lower cover part groove inside the lower cover part, and a lower cover part cylindrical air hole with more internal protrusions and fewer external protrusions; in step S200, use a stereolithography 3D printer and use black resin as the printing material for printing; for the upper cover part, select the side without the groove as the base surface, and remove the supports inside the cylindrical air hole and in the groove when setting the supports; for the lower cover part, select the side opposite to the side without the groove as the base surface, and remove the supports inside the cylindrical air hole and in the groove when setting the supports; in step S300, immerse the printed upper cover part and lower cover part in alcohol and ultrasonically clean them for 20 minutes. After cleaning, place the printed parts in an ultraviolet curing oven. After taking them out, cure them under the condition of 35 °C for 30 min. After curing, remove the supports.

[0015] For the sealing washer part, in step S100, the sealing washer is modeled using 3D modeling software. The sealing washer has a sealing washer skirt and a sealing washer groove; in step S200, a stereolithography 3D printer is used, and 50A resin is used as the printing material for printing. The side without the groove is selected as the base surface, and all supports are set on the base surface of the sealing washer; in step S300, the printed sealing washer is soaked in alcohol for 10 minutes. After soaking, the supports are removed first. After the supports are removed completely, the printed part is placed in an ultraviolet curing box and ultraviolet cured at 35 °C for 10 min.

[0016] In step S400, the splicing process includes the following steps:

[0017] S401, positioning: The skirt of the origami part is fitted with the grooves of the upper cover part and the lower cover part for positioning;

[0018] S402, sealing: After positioning, an appropriate amount of 50A resin is added to the designed grooves of the upper cover part and the lower cover part, and it is placed in an ultraviolet curing box at 35 °C for 10 minutes. After the resin is cured, a good sealing effect can be achieved;

[0019] S403, combination: After the upper cover part and the origami part, and the lower cover part and the origami part respectively complete the above positioning and sealing, a single Kresling-type origami structure is assembled.

[0020] A single Kresling-type origami structure is connected by a sealing washer. First, the sealing washer is placed into the lower cover part of a Kresling-type origami structure and positioned through the groove of the lower cover part. Then, the cylindrical air hole of the upper cover part of another Kresling-type origami structure is inserted into the sealing washer to form a combination of multiple Kresling-type origami structures.

[0021] Compared with the prior art, the advantages of the present invention are as follows:

[0022] The present invention solves the process difficulties of manufacturing Kresling-type origami structures by 3D printing, and successfully manufactures Kresling-type origami structures with strong folding ability, good flexibility and airtightness, and self-recovery during the service life. And it simplifies the design and manufacturing process. When designing a new Kresling-type origami structure, only the overall model of the origami part needs to be established. During manufacturing, the origami part of the Kresling-type origami structure can be manufactured at one time, and the subsequent assembly process only requires three components to be quickly spliced according to the designed positioning structure.

[0023] The present invention not only provides a simple manufacturing method for designing Kresling - type origami structures, but also provides a reliable solution for the mass production of Kresling - type origami structures. Description of the Drawings

[0024] The drawings illustrate exemplary embodiments of the present invention and, together with the description thereof, are used to explain the principles of the present invention. These drawings are included to provide a further understanding of the present invention and are included in this specification and form a part of this specification.

[0025] Figure 1 is a process flow chart of the manufacturing process of Kresling - type origami structures;

[0026] Figure 2 is a schematic diagram of an embodiment of a Kresling - type origami structure;

[0027] Figure 3 is a schematic diagram of the support setting of the origami part in the embodiment;

[0028] Figure 4 is a schematic diagram of the support setting of the upper cover part and the lower cover part in the embodiment;

[0029] Figure 5 is a schematic diagram of the support setting of the sealing gasket in the embodiment;

[0030] Figure 6 is a schematic diagram of positioning and sealing in the splicing process of the embodiment;

[0031] Figure 7 is a schematic diagram of the combination process in the splicing process of two Kresling - type origami structures in the embodiment;

[0032] Figure 8 is a schematic diagram of a Kresling - type origami structure in the embodiment;

[0033] In the drawings:

[0034] 1 - origami part; 2 - upper cover part; 3 - lower cover part; 4 - sealing gasket;

[0035] 11 - defect; 12 - skirt of the origami part; 13 - crease of the origami part; 14 - two sides of the crease of the origami part; 21 - groove of the upper cover part; 22 - cylindrical air hole of the upper cover part; 31 - groove of the lower cover part; 32 - cylindrical air hole of the lower cover part; 41 - skirt of the sealing gasket; 42 - groove of the sealing gasket;

[0036] 212 - origami part; 2121 - defective surface; 2122 - non - defective surface; 21211 - defective triangular facet; 21212 - defective crease; 21221 - non - defective surface triangular facet; 21222 - non - defective surface crease. Detailed Implementation Modes

[0037] The following will further elaborate on the present invention in conjunction with the appended Figures 1 to 8 drawings and implementation modes. It can be understood that the specific implementation modes described herein are only used to explain the relevant content and do not limit the present invention. Additionally, it should be noted that for the sake of description, only the parts related to the present invention are shown in the drawings.

[0038] It should be noted that, without conflict, the implementation modes in the present invention and the features in the implementation modes can be combined with each other. The following will detail the technical solutions of the present invention with reference to the drawings and in conjunction with the implementation modes.

[0039] Unless otherwise specified, the exemplary implementation modes / embodiments shown will be understood to provide exemplary features of various details of some ways that can implement the technical concept of the present invention in practice. Therefore, unless otherwise specified, without departing from the technical concept of the present invention, the features of various implementation modes / embodiments can be additionally combined, separated, interchanged, and / or rearranged.

[0040] In the drawings, hatching and / or shading are generally used to make the boundaries between adjacent components clear. Thus, unless stated otherwise, the presence or absence of hatching or shading does not convey or imply any preference or requirement for the specific material, material properties, dimensions, proportions, commonality between the components shown, and / or any other characteristics, attributes, properties, etc. of the components. Additionally, in the drawings, for clarity and / or descriptive purposes, the dimensions and relative dimensions of the components may be exaggerated. When the exemplary embodiments can be implemented differently, the specific process sequences can be executed in an order different from that described. For example, two consecutively described processes can be executed substantially simultaneously or in an order opposite to that described. Furthermore, the same reference numerals denote the same components.

[0041] When a component is referred to as being "on" or "above" another component, "connected to" or "coupled to" another component, the component can be directly on the other component, directly connected to or directly coupled to the other component, or there may be intermediate components. However, when the component is referred to as being "directly on" another component, "directly connected to" or "directly coupled to" another component, there are no intermediate components. For this reason, the term "connection" can refer to physical connection, electrical connection, etc., and may or may not have intermediate components.

[0042] For descriptive purposes, the present invention may use spatial relative terms such as "under", "below", "beneath", "lower", "above", "upper", "on", "higher", and "side (e.g., as in "side wall") to describe the relationship of one component to another (other) component as shown in the drawings. In addition to the orientation depicted in the drawings, the spatial relative terms are also intended to encompass different orientations of the device during use, operation, and / or manufacturing. For example, if the device in the drawings is flipped, a component described as "under" or "beneath" another component or feature will then be positioned "above" the other component or feature. Thus, the exemplary term "under" can encompass both the "above" and "below" orientations. Additionally, the device may be otherwise positioned (e.g., rotated 90 degrees or at other orientations), and accordingly, the spatial relative descriptors used herein are to be interpreted accordingly.

[0043] The terms used herein are for the purpose of describing particular embodiments and are not intended to be limiting. As used herein, unless the context clearly indicates otherwise, the singular forms "a", "an", and "the" are also intended to include the plural forms. Additionally, when the terms "comprise" and / or "include" and their variants are used in this specification, it is stated that there are the stated features, integers, steps, operations, components, assemblies, and / or groups thereof, but it does not preclude the presence or addition of one or more other features, integers, steps, operations, components, assemblies, and / or groups thereof. It should also be noted that, as used herein, the terms "substantially", "about", and other similar terms are used as approximate terms and not as terms of degree, and thus they are used to explain the inherent deviations of measured, calculated, and / or provided values that would be recognized by those of ordinary skill in the art.

[0044] A manufacturing process for a Kresling - type origami structure based on 3D printing, which comprises the following method steps:

[0045] S100. Modeling each part of the Kresling - type origami structure through 3D modeling software to obtain 3D models of each part of the Kresling - type origami structure; the Kresling - type origami structure includes: an origami part, an upper cover part, a lower cover part, and a sealing gasket part; converting the 3D models of each part of the Kresling - type origami structure into a file in a format supported by a 3D printer;

[0046] During the process of establishing the 3D model, according to the accuracy of the 3D printer used, set the structural parameters and positioning structural parameters of each part respectively; after the modeling is completed, save the Kresling - type origami structure in STL format for importing into the slicing software of the 3D printer;

[0047] S200, input the file, select the material for 3D printing and set the printing parameters; select the printing base surface and set the position of the support for printing, and obtain the structures of the various parts of the Kresling-like origami structure;

[0048] S300, post-processing each part of the Kresling-like origami structure, soaking each part of the structure in alcohol and then placing it in a UV curing box for curing; after the curing is completed, the support is removed to obtain the finished parts of the Kresling-like origami structure;

[0049] S400, splicing the finished parts of the Kresling-like origami structure according to the splicing process to obtain the Kresling-like origami structure.

[0050] Wherein, S200 includes the following steps:

[0051] S201, open the slicing software that comes with the 3D printer, and import the established 3D model in STL format (including the origami part, the upper cover, the lower cover, and the sealing gasket) into the software interface;

[0052] S202, select printing material and printing precision. Different materials and printing precisions are selected for different models and requirements. The black resin adopts a printing precision of 0.1mm, the 80A resin adopts a printing precision of 0.05mm, and the 50A resin adopts a printing precision of 0.1mm;

[0053] S203, selecting a printing base surface, that is, starting from this surface, printing is piled up layer by layer until printing is completed. Reasonable selection of the printing base surface can improve the printing quality and success rate;

[0054] S204, setting support. As an essential step for 3D printing, the reasonable arrangement of the size and position of the support will determine the printing quality. For three different printing materials (black resin, 80A resin, 50A resin), the size of the support point is selected as 0.3-0.4mm, and the support point density is 1, so that the support can be removed later. The rest of the parameters are default.

[0055] S205, generate support, upload slice file, click upload;

[0056] S206. Ensure that the resin tank and resin box materials are consistent with the selected printing materials, ensure that the printing platform is clean and tidy, select the uploaded slice file on the printer interface, and click print to start printing;

[0057] S207, wait for printing to be completed and remove the model.

[0058] In step S100, for the origami part, model the origami part using 3D modeling software; after the model is built, export it in the STL file format for 3D printing.

[0059] In step S100, for the origami part, set the crease parameters and positioning structure parameters of the origami part according to the accuracy of the 3D printer used; there is a skirt on the upper side of the origami part that cooperates with the upper cover part, and a skirt on the lower side of the origami part that cooperates with the lower cover part.

[0060] In step S200, for the origami part, use a stereolithography 3D printer, use 80A transparent resin as the printing material and set the printing parameters; select the upper and lower bottom surfaces of the origami part as the printing bases, and all supports are set at the bottom; only a small amount of supports are set at the newly designed structures on the basis of the Kresling origami structure inside the cavity, and all supports grow from the bottom.

[0061] In step S300, for the origami part, soak the whole origami part print in alcohol for 10 minutes, after soaking, put the print into an ultraviolet curing box, and cure it under the condition of 60 °C for 10 min with ultraviolet light, and then remove the supports after taking it out.

[0062] For the upper cover part and the lower cover part, in step S100, model the upper cover part and the lower cover part using 3D modeling software. There is an upper cover part groove inside the upper cover part, and an externally convex upper cover part cylindrical air hole outside; there is a lower cover part groove inside the lower cover part, and a lower cover part cylindrical air hole that protrudes more inside and less outside; in step S200, use a stereolithography 3D printer and use black resin as the printing material for printing; for the upper cover part, select the side without the groove as the base surface, and remove the supports inside the cylindrical air hole and in the groove when setting the supports; for the lower cover part, select the side opposite to the side without the groove as the base surface, and remove the supports inside the cylindrical air hole and in the groove when setting the supports; in step S300, soak the upper cover part and lower cover part prints in alcohol and ultrasonically clean them for 20 minutes. After cleaning, put the prints into an ultraviolet curing box, take them out and cure them under the condition of 35 °C for 30 min with ultraviolet light, and remove the supports after curing.

[0063] For the sealing gasket part, in step S100, model the sealing gasket using 3D modeling software. The sealing gasket has a sealing gasket skirt and a sealing gasket groove; in step S200, use a stereolithography 3D printer, use 50A resin as the printing material for printing, select the side without the groove as the base surface, and set all the supports on the base surface of the sealing gasket; in step S300, soak the sealing gasket print in alcohol for 10 minutes, first remove the supports after soaking, and then put the print into an ultraviolet curing box and cure it under the condition of 35 °C for 10 min with ultraviolet light after the supports are removed.

[0064] In step S400, the splicing process includes the following steps:

[0065] S401. Positioning: Fit the skirt of the origami part with the grooves of the upper cover part and the lower cover part for positioning;

[0066] S402. Sealing: After positioning, add an appropriate amount of 50A resin into the designed grooves of the upper cover part and the lower cover part, and place it in an ultraviolet curing box at 35 °C for 10 minutes. After the resin cures, a good sealing effect can be achieved;

[0067] S403. Assembly: After the upper cover part and the origami part, and the lower cover part and the origami part respectively complete the above positioning and sealing, a single Kresling - type origami structure is assembled.

[0068] Single Kresling - type origami structures are connected by a sealing gasket. First, place the sealing gasket into the lower cover part of a Kresling - type origami structure for positioning through the groove of the lower cover part. Then, insert the cylindrical air hole of the upper cover part of another Kresling - type origami structure into the sealing gasket to form a combination of multiple Kresling - type origami structures.

[0069] In one embodiment, the present invention provides a manufacturing process of Kresling - type origami structures based on 3D printing, specifically including: the manufacturing process of the origami part; the manufacturing process of the upper cover part and the lower cover part; the manufacturing process of the sealing gasket; the splicing process of Kresling - type origami structures.

[0070] Refer to Figure 1 , to illustrate the processes of each part. The manufacturing process of the origami part includes the following steps:

[0071] (a) Model establishment: Model the origami part through 3D modeling software. Commonly used CAD software such as UG and SolidWorks can be used for modeling. After the model is established, export it in the STL file format for 3D printing. When designing the appearance of the origami part, it is necessary to ensure that positioning skirts are provided on the upper and lower sides to ensure accurate fitting when the origami part is spliced with the upper cover part and the lower cover part, and at the same time increase the strength of the connection part.

[0072] When modeling, set the crease parameters of the origami part according to the accuracy of the 3D printer used. The crease is a groove with a certain width and a certain depth. The width of the crease is determined by the angle formed after the two faces connected by the crease are completely folded and the thickness of the two faces. The smaller the thickness at the crease and the thickness of the two faces connected by the crease, the smaller the overall size that the Kresling origami structure can achieve, but the minimum thickness at the crease is limited by the printer accuracy and the working load at the crease.

[0073] (b) 3D printing: The origami part of the Kresling-like origami structure uses a photocuring 3D printer. Because the 80A resin material can simulate the flexibility of rubber, it can withstand bending, deflection and compression, and can maintain this property for a long time even under repeated cycles, which can well meet the needs of the origami part of the Kresling-like origami structure, so 80A transparent resin is used as the printing material. When 3D printing, it is necessary to set a support structure, including a base surface and support points, and select one of the upper and lower bottom surfaces as the printing base surface; due to the structural particularity of the origami structure, the support points cannot be set arbitrarily, otherwise it will make the support points difficult to remove and affect the performance of the origami structure, so the position of the support points needs to be set reasonably. At the same time, the number of support points should be as small as possible and avoid appearing in relatively weak areas such as the crease part. Except for the parts necessary to meet the support strength, the support points are set at the bottom as much as possible. Only a small number of support points are set at the newly designed structure based on the Kresling origami structure inside the cavity, and all supports are grown from the bottom as much as possible.

[0074] (c) Subsequent processing: Soak the entire printed part in 99% alcohol for 10 minutes to clean the residual resin on the surface of the printed part. Soaking for too long will cause wrinkles or even damage to the thinner parts, affecting the overall performance of the structure. After soaking, put the printed part in a UV curing box and UV cure it at 60°C for 10 minutes. Remove the support after taking it out. This is because the origami structure that has just been printed is relatively fragile. Forcibly removing the support before curing may cause damage to the structure. Therefore, it needs to be cured first and then the support is removed.

[0075] The manufacturing process of the upper cover part and the lower cover part includes the following steps:

[0076] (a) Model building: The upper cover part and the lower cover part are modeled by three-dimensional modeling software. The upper cover part is provided with a groove inside and a cylindrical pore of the upper cover part protruding outside; the lower cover part is provided with a groove inside and a cylindrical pore of the lower cover part protruding more inside and less outside. The groove has two functions: (1) as a positioning structure, it cooperates with the skirt of the origami part to ensure the accurate positioning of the upper cover part, the lower cover part and the origami part when spliced; (2) when the internal air pressure of the Kresling origami structure increases, the skirt of the origami part tends to be squeezed outward. The provision of the groove allows the skirt to cooperate more closely with the upper cover part and the lower cover part when it is subjected to the outward squeezing force, thereby improving the strength of the Kresling origami structure.

[0077] (b) 3D printing: The upper cover part and the lower cover part use a stereolithography 3D printer. The upper cover part and the lower cover part need to be spliced with the skirt of the origami part later. Using resin materials for the upper cover part and the lower cover part can increase the reliability of the splicing. However, since the skirt of the origami part has relatively high requirements for the fitting accuracy, it is necessary to ensure the machining accuracy of the grooves in the upper cover part and the lower cover part. The 80A transparent resin material is difficult to meet the requirements, so a different resin material needs to be used. The black resin has relatively high toughness and strength, a smooth surface and high precision, and can still maintain good mechanical properties at high temperatures. Therefore, the upper cover part and the lower cover part are printed using black resin as the printing material. When choosing the 3D printing base surface, the machining accuracy problem also needs to be considered. Select the other side opposite to the groove as the base surface. When setting the support points, the supports inside the cylindrical air holes and at the grooves should be removed to ensure the surface quality of the cylindrical air holes and the grooves.

[0078] (c) Post-treatment: Immerse the printed upper cover part and lower cover part in alcohol with a concentration of 99% and ultrasonically clean for 20 minutes. Since the black resin is more difficult to clean than the 80A transparent resin, in order to ensure that the resin inside the grooves is cleaned thoroughly, it is necessary to put them into an ultrasonic cleaner for ultrasonic cleaning during immersion. After cleaning, put the printed parts into an ultraviolet curing box and cure them under ultraviolet light at 35°C for 30 minutes. After curing, remove the supports. This is also because the just-printed upper cover part and lower cover part are relatively fragile, and forcibly removing the supports without curing may cause structural damage. Therefore, it is necessary to cure first and then remove the supports.

[0079] The manufacturing process of the sealing gasket includes the following steps:

[0080] (a) Model establishment: Model the sealing gasket through 3D modeling software. The sealing gasket has a skirt and a groove. The function of the skirt and the groove of the sealing gasket is to wrap the cylindrical air holes in the lower cover part of the Kresling-type origami structure to ensure better airtightness.

[0081] (b) 3D printing: The sealing gasket uses a stereolithography 3D printer. The 50A resin material has a lower hardness, is soft in texture, and has good durability, making it a suitable material for the sealing gasket. Therefore, 50A resin is used as the printing material for the sealing gasket for printing. When choosing the 3D printing base surface, select the large circular surface as the base surface and set all the support points at the bottom of the gasket. The number of supports should not be too many or too few. Too many are difficult to remove, and too few may cause printing failure.

[0082] (c) Post-treatment: Immerse the printed sealing washer in alcohol with a concentration of 90% for 10 minutes. Do not use ultrasonic cleaning to remove the residual 50A resin on the surface of the printed part. Ultrasonic cleaning is not used because it will cause damage to the washer. After immersion, first remove the support. After the support is removed, place the printed part in an ultraviolet curing box and cure it under ultraviolet light at 35°C for 10 minutes. Since the support of the 50A resin printed part is easily removed after immersion in alcohol, the support is removed first and then curing is carried out.

[0083] The splicing process of the Kresling-type origami structure includes the following steps:

[0084] (a) Positioning: Fit the skirt of the origami part with the grooves of the upper cover part and the lower cover part for positioning.

[0085] (b) Sealing: After positioning, add an appropriate amount of 50A resin to the designed grooves of the upper cover part and the lower cover part, and place it in an ultraviolet curing box at 35°C for 10 minutes. After the resin is cured, it can achieve a good sealing effect. The reason for adding 50A resin to the groove is that the origami part, the upper cover part, and the lower cover part are all made of resin material. Adding resin between them can achieve better sealing by relying on resin compatibility. At the same time, because 50A resin is soft in texture and cures quickly, 50A resin is selected as the bonding material.

[0086] (c) Assembly: During splicing, the origami part can only be positioned and sealed with one of the upper cover part and the lower cover part each time. After the upper cover part and the origami part, and the lower cover part and the origami part are respectively positioned and sealed as described above, a single Kresling-type origami structure is assembled. Multiple Kresling-type origami structures can be connected through a sealing washer. First, place the sealing washer inside the lower cover part of a Kresling-type origami structure. The skirt and groove of the sealing washer wrap around the cylindrical air hole of the lower cover part for positioning. Then, insert the protruding cylindrical hole of the upper cover part of another Kresling-type origami structure into the sealing washer. This fit is an interference fit, which achieves a good sealing effect.

[0087] In this embodiment, a stereolithography 3D printer, model Formlabs form 3, is used. The printing accuracy for the black resin is 0.1 mm. The printer has printing accuracies of 0.1 mm, 0.05 mm, and 0.025 mm for the black resin. The accuracy requirements for the upper and lower covers printed with the black resin are not high. To improve the printing speed, a printing accuracy of 0.1 mm is adopted; the printing accuracy for the 80A resin is 0.05 mm. The printer has printing accuracies of 0.1 mm and 0.05 mm for the 80A resin. Since the accuracy requirements for the origami part are relatively high, a printing accuracy of 0.05 mm is adopted; the printing accuracy for the 50A resin is 0.1 mm, and the default printing accuracy is 0.1 mm.

[0088] In one embodiment, the present invention provides a manufacturing process for a Kresling - type origami structure based on 3D printing, which is used to manufacture an actuator module unit of a multi - directional origami structure pneumatic soft actuator based on air pressure control, as Figure 2 shown. When the actuator is driven by a single trachea by introducing defects 11 with different depths on multiple folding surfaces of the kresling origami structure, by changing the air pressure inside the actuator, the transformation of the defect state can be achieved, thereby changing the motion mode of the actuator.

[0089] In one embodiment, referring to Figure 8 , the defective surface 2121 of the origami part 212 is composed of four triangular facets with a certain thickness. The four defective triangular facets 21211 are connected by defective creases 21212; the defective triangular facets 21211 are thicker than the non - defective surface 2122. During operation, by changing the air pressure inside the cavity, under the action of gas pressure, the defective triangular facets 21211 can be pushed outward or inward, so that the defect changes between the two states of indentation and protrusion. The defective creases 21212 are thinner than the non - defective surface 2122, and the defective triangular facets 21211 can rotate smoothly around the defective creases 21212 without secondary processing; as Figure 8 shown in (e) of , the non - defective surface 2122 of the origami part is composed of two symmetric non - defective surface triangular facets 21221 with a certain thickness. The two facets are connected by a non - defective surface crease 21222. This crease design can achieve the air - extraction and contraction function without secondary processing; the defect can be indented to different depths inside the cavity.

[0090] The manufacturing process for the Kresling - type origami structure based on 3D printing includes: (1) the manufacturing process for the origami part 1; (2) the manufacturing processes for the upper cover part 2 and the lower cover part 3; the manufacturing process for the sealing gasket 4; the splicing process for the Kresling - type origami structure.

[0091] The manufacturing process for the origami part in this embodiment includes the following steps:

[0092] (a) Model building

[0093] S11, modeling the origami part using 3D modeling software;

[0094] In this embodiment, SolidWorks is used to build the model, and after the model is built, the STL file format is exported for 3D printing.

[0095] S12. According to the accuracy of the 3D printer used, the crease parameters and positioning structure parameters of the origami part are set.

[0096] According to the accuracy of the 3D printer used, the parameters of the fold 13 of the origami part designed in this embodiment are: the thickness of the thinnest part of the fold groove is 0.3mm; the thickness of the two sides 14 of the origami part fold is 1mm; the maximum width of the fold is 2mm; the size of the origami part 1 is: the length of the hexagon of the origami part is 15mm; the height of the origami part is 15mm. When designing the appearance of the origami part 1, the upper and lower sides are provided with origami part skirts 12, and the thickness is 0.9mm.

[0097] The thinnest part of the crease groove is 0.3mm because this thickness allows the groove to fold like a crease, and the printing accuracy of the printer and the strength of the material are taken into consideration. If it is less than 0.3mm, the actuator may be easily damaged during use and difficult to print, and if it is more than 0.3mm, it will be difficult to fold.

[0098] The reason why 1mm is chosen for the two sides of the crease is that when the thickness is 1mm, the entire surface has a certain rigidity, and it is not easy to deform when the groove is folded, which is closer to rigid folding. If the thickness continues to increase, although the rigidity will increase, the excessive thickness will cause interference in the folding, which is not conducive to the folding of the entire structure.

[0099] The maximum width of the crease is 2mm because this size can ensure that when the thickness of the two sides of the crease is 1mm, there will be no interference in folding. If it is higher than 2mm, it will be detrimental to the deformation of the entire structure like origami.

[0100] The hexagonal side length of the origami part is 15mm, and the height of the origami part is 15mm. This size is not mandatory, but in order for the entire actuator to work properly and be easy to prepare, the two sizes should not be less than 10mm; for convenience, the entire model can be scaled proportionally;

[0101] Reference Figure 6 The upper and lower sides of the folding part are provided with folding part skirts 12, which are positioned and matched with the grooves of the upper cover part and the lower cover part.

[0102] (b) 3D printing part

[0103] S21. Import the STL file format for 3D printing;

[0104] S22. Select the 3D printing material and set the printing parameters;

[0105] In this embodiment, the origami part 1 uses a stereolithography 3D printer and 80A transparent resin as the printing material. The printing parameters are set to 0.05 mm per layer, the support density is set to 1, and the contact point size is set to 0.3 mm. Supports are set. Reasonably arranging the size and position of the supports will determine the printing quality. For the three different printing materials (black resin, 80A resin, 50A resin), the size of the support points is selected to be 0.3 - 0.4 mm. The size should not be too large so as to remove the supports later. The support point density is 1, and the rest of the parameters are default.

[0106] S23. Select the printing base surface and set the positions of the support points for printing;

[0107] In this embodiment, the lower bottom surface of the origami part 1 is selected as the printing base surface, as shown in (b) below. The number of support points should be as few as possible and avoid weak areas such as the crease part. Except for the necessary parts, all support points are set at the bottom. Only a small number of support points are set at the newly designed structures on the basis of the Kresling origami structure inside the cavity. In this embodiment, the newly designed structure is the defect 11, as shown in (c) below. All the support points inside the cavity are set on the defect 11. The model of the origami part after adding supports is shown in (d) below. Figure 3 Figure 3 Figure 3

[0108] (c) Follow-up processing part

[0109] S31. Immerse the whole printed part in 99% concentration alcohol for 10 minutes;

[0110] Immersing in 99% concentration alcohol for ten minutes is to wash off the residual resin on the surface of the printed part that has been printed. The immersion time should not be too long, otherwise it will damage the printed part;

[0111] S32. Put the immersed printed part into an ultraviolet curing box and cure it under ultraviolet light at 60 °C for 10 min; The best curing condition for 80A resin is to cure it under ultraviolet light at 60 °C for 10 min, and relatively stable performance can be obtained;

[0112] S33. Remove the supports after curing to complete the manufacture of the origami part.

[0113] The manufacturing process of the upper cover part and the lower cover part in this embodiment includes the following steps:

[0114] (a) Establish a model

[0115] ​​​S111. Model the upper cover part and the lower cover part respectively using 3D modeling software;

[0116] Use Solidworks to model the upper cover part 2 and the lower cover part 3. After the model is completed, export it in STL file format for 3D printing.

[0117] S112. Set the positioning structure parameters of the upper cover part and the lower cover part according to the accuracy of the 3D printer used;

[0118] Refer to Figure 4 , there is an upper cover part groove 21 inside the upper cover part, and an outwardly convex upper cover part cylindrical air hole 22 outside the upper cover part; for the upper and lower covers with a hexagonal size of 15 mm, set the height to 6 mm. At this height, there can be a certain mating length with the sealing washer, but it should not be too high, otherwise it may interfere with other series-connected actuators during folding.

[0119] There is a lower cover part groove 31 inside the lower cover part 3, and a lower cover part cylindrical air hole 32 that protrudes more inside and less outside. The widths of the upper cover part and lower cover part grooves are 1 mm, and the wall thicknesses of the upper cover part and lower cover part cylindrical air holes are 2 mm.

[0120] (b) 3D printing

[0121] S221. Import the STL file format for 3D printing;

[0122] S222. Select the material for 3D printing and set the printing parameters;

[0123] Use black resin as the printing material to print the upper cover part 2 and the lower cover part 3. Set the printing parameters to 0.1 mm per layer, the support density to 1, and the contact point size to 0.3 mm.

[0124] S223. Select the printing base surface and set the positions of the support points for printing;

[0125] Select the other side opposite to the groove as the base surface as shown in Figure 4 (b). When setting the support points, the support points inside the cylindrical air holes and in the grooves should be removed as shown in Figure 4 (c). The folded paper part model after adding supports is shown in Figure 4 (d).

[0126] (c) Subsequent processing

[0127] S331. Immerse the printed parts of the upper cover part 2 and the lower cover part 3 in 99% concentrated alcohol and ultrasonically clean for 20 minutes;

[0128] S332. After cleaning, put the printed parts into an ultraviolet curing box and cure them under ultraviolet light at 35 °C for 30 min;

[0129] S333. After curing, remove the support.

[0130] The manufacturing process of the sealing gasket in this embodiment includes the following steps:

[0131] (a) Model establishment

[0132] S1111. Model the sealing gasket respectively through 3D modeling software;

[0133] Use Solidworks to model the sealing gasket. After the model is established, export it in STL file format for 3D printing.

[0134] S1112. Set the positioning structure parameters of the upper cover part and the lower cover part according to the accuracy of the 3D printer used;

[0135] The sealing gasket 4 is provided with a sealing gasket skirt 41 and a sealing gasket groove 42. The width of the sealing gasket groove is 2 mm, and the protruding height of the skirt is 1 mm.

[0136] (b) 3D printing

[0137] S2221. Import the STL file format for 3D printing;

[0138] S2222. Select the material for 3D printing and set the printing parameters;

[0139] Use 50A resin as the printing material for printing. The printing parameters are set as 0.1 mm per layer, the support density is set to 1, and the contact point size is set to 0.3 mm.

[0140] S2223. Select the printing base surface and set the positions of the support points for printing;

[0141] Select the large circular surface as the base surface. As shown in Figure 5 (b), set all the support points at the bottom of the gasket. As shown in Figure 5 (c), the model of the origami part after adding support is as shown in Figure 5 (d).

[0142] (c) Post-treatment

[0143] S3331. Immerse the printed sealing gasket in 99% concentration alcohol for 10 minutes without ultrasonic cleaning;

[0144] S3332. After soaking, first remove the support because the support of the 50A resin printed part is easy to remove after soaking;

[0145] After the support is removed, place the printed part in an ultraviolet curing box and cure it under ultraviolet light at 35°C for 10 minutes.

[0146] The structure splicing process of this embodiment includes the following steps:

[0147] 1. First, position and seal the upper cover part 2 and the origami part 1:

[0148] (a) Positioning: As shown in Figure 6 , fit the skirt 12 of the origami part with the groove 21 of the upper cover part for positioning.

[0149] (b) Sealing: As shown in Figure 6 , after positioning, add an appropriate amount of 50A resin to the designed groove 21 of the upper cover part, place it in an ultraviolet curing box at 35°C for 10 minutes. After the resin cures, a good sealing effect can be achieved to complete.

[0150] 2. Then, position and seal the lower cover part 2 and the origami part 1:

[0151] (a) Positioning: As shown in Figure 6 , fit the skirt 12 of the origami part with the groove 31 of the lower cover part for positioning.

[0152] (b) Sealing: As shown in Figure 6 , after positioning, add an appropriate amount of 50A resin to the designed groove 31 of the lower cover part, place it in an ultraviolet curing box at 35°C for 10 minutes. After the resin cures, a good sealing effect can be achieved to complete.

[0153] After the above steps are completed, a Kresling - type origami structure can be manufactured.

[0154] Next, combination: Multiple Kresling - type origami structures can be connected through sealing washers. Taking two as an example, the finished product is as shown in Figure 7 (a). The combination method is as shown in Figure 7 (b). First, place the sealing washer into the cylindrical air hole 32 of the lower cover part of the upper Kresling - type origami structure. The sealing washer has a special groove 42 for positioning. Then, insert the cylindrical air hole 22 of the upper cover part of another Kresling - type origami structure into the sealing washer. This fit is an interference fit, which can achieve a good sealing effect. Finally, rotate and adjust the positional relationship between the two Kresling - type origami structures to reach the required position.

[0155] In the description of this specification, the description referring to terms such as "one embodiment / way", "some embodiments / ways", "example", "specific example", or "some examples", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment / way or example are included in at least one embodiment / way or example of this application. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment / way or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments / ways or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments / ways or examples described in this specification and the features of different embodiments / ways or examples.

[0156] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of this application, "a plurality" means at least two, such as two, three, etc., unless otherwise specifically and clearly defined.

[0157] Those skilled in the art should understand that the above embodiments are merely for clearly illustrating the present invention and are not intended to limit the scope of the present invention. For those skilled in the art, other changes or modifications can be made on the basis of the above disclosure, and these changes or modifications are still within the scope of the present invention.

Claims

1. A manufacturing process for Kresling - like origami structures based on 3D printing, characterized in that, It includes the following steps: S100. Model each part of the Kresling - type origami structure through 3D modeling software to obtain 3D models of each part of the Kresling - type origami structure; the Kresling - type origami structure includes: an origami part, an upper cover part, a lower cover part, and a sealing gasket part; convert the 3D models of each part of the Kresling - type origami structure into files in a format supported by the 3D printer; according to the accuracy of the 3D printer used, set the structural parameters and positioning structural parameters of each part respectively; S200. Input the file, select the material for 3D printing and set the printing parameters; Select the printing base surface and set the position of the support for printing to obtain the structural parts of the Kresling - type origami structure; S300. Post - process the structural parts of the Kresling - type origami structure, soak each part in alcohol and then put it into an ultraviolet curing box for curing; after curing, remove the support to obtain the finished products of the structural parts of the Kresling - type origami structure; S400. Assemble the finished products of the structural parts of the Kresling - type origami structure according to the assembly process to obtain the kersling - type origami structure.

2. The manufacturing process of the Kresling-like origami structure based on 3D printing according to claim 1, characterized in that, Preferably, in step S100, for the origami part, model the origami part through 3D modeling software; after the model is established, export it in the STL file format for 3D printing.

3. The manufacturing process of the Kresling - like origami structure based on 3D printing according to claim 2, characterized in that, In step S100, for the origami part, according to the accuracy of the 3D printer used, set the crease parameters and positioning structural parameters of the origami part; there is a skirt on the upper side of the origami part that cooperates with the upper cover part, and a skirt on the lower side of the origami part that cooperates with the lower cover part.

4. The manufacturing process of the Kresling-like origami structure based on 3D printing according to claim 3, characterized in that, In step S200, for the origami part, use a stereolithography 3D printer, use 80A transparent resin as the printing material and set the printing parameters; select the upper and lower bottom surfaces of the origami part as the printing base surface, and set all the supports at the bottom; Only a small amount of support is set at the newly designed structure in the cavity based on the Kresling origami structure, and all supports grow from the bottom.

5. The manufacturing process of the Kresling-like origami structure based on 3D printing according to claim 4, characterized in that, In step S300, for the origami part, soak the entire printed part of the origami part in alcohol for 10 minutes, after soaking, put the printed part into an ultraviolet curing box, cure it under ultraviolet light at 60 °C for 10 min, and then remove the support after taking it out.

6. The manufacturing process of the Kresling - like origami structure based on 3D printing according to claim 5, characterized in that, For the upper cover part and the lower cover part, in step S100, model the upper cover part and the lower cover part through 3D modeling software. There is an upper - cover - part groove inside the upper cover part, and an outward - protruding cylindrical air hole of the upper cover part outside; There is a lower - cover - part groove inside the lower cover part, and a cylindrical air hole of the lower cover part that protrudes more inside and less outside; In step S200, use a stereolithography 3D printer and use black resin as the printing material for printing; For the upper cover part, select the side without grooves as the base surface, and remove the supports inside the cylindrical air holes and at the grooves when setting the supports; for the lower cover part, select the side opposite to the side without grooves as the base surface, and remove the supports inside the cylindrical air holes and at the grooves when setting the supports; in step S300, soak the printed parts of the upper cover part and the lower cover part in alcohol and ultrasonically clean them for 20 minutes. After cleaning, put the printed parts into an ultraviolet curing box, take them out and cure them under ultraviolet light at 35 °C for 30 min. After curing, remove the supports.

7. The manufacturing process of the Kresling-like origami structure based on 3D printing according to claim 6, wherein, For the sealing gasket part, in step S100, model the sealing gasket through 3D modeling software. The sealing gasket has a sealing gasket skirt and a sealing gasket groove; in step S200, use a stereolithography 3D printer and use 50A resin as the printing material for printing. Select the side without grooves as the base surface and set all the supports on the base surface of the sealing gasket; in step S300, soak the printed sealing gasket in alcohol for 10 minutes. After soaking, first remove the supports. After the supports are removed completely, put the printed part into an ultraviolet curing box and cure it under ultraviolet light at 35 °C for 10 min.

8. The manufacturing process of the Kresling - like origami structure based on 3D printing according to claim 7, characterized in that, In step S400, the splicing process includes the following steps: S401, positioning: Fit the skirt of the origami part with the grooves of the upper cover part and the lower cover part for positioning; S402, sealing: After positioning, add an appropriate amount of 50A resin into the designed grooves of the upper cover part and the lower cover part, and place it in an ultraviolet curing box at 35 °C for 10 minutes. After the resin cures, it can achieve a good sealing effect; S403, combination: After the upper cover part and the origami part, and the lower cover part and the origami part respectively complete the above positioning and sealing, a single Kresling-type origami structure is assembled.

9. The manufacturing process of the Kresling-like origami structure based on 3D printing according to claim 8, characterized in that, A single Kresling-type origami structure is connected by a sealing gasket. First, put the sealing gasket into the lower cover part of a Kresling-type origami structure for positioning through the groove of the lower cover part, and then insert the cylindrical air hole of the upper cover part of another Kresling-type origami structure into the sealing gasket to form a combination of multiple Kresling-type origami structures.

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