Low-buckling-deformation 3D printing structure

Abstract

The utility model discloses a 3D printing structure with low buckling deformation, and belongs to the technical field of 3D printing. According to the structure, a perforated plate made of the same material as a printing material is adopted as a printing base plate, and the connection force between a printing piece and the base plate is enhanced through an embedded structure formed by enabling a molten-state material to enter base plate holes and heat fusion; the printed piece is segmented in the growth direction, a counter bore is formed in the upper portion of each segment, and a molten-state material enters the counter bores to form an embedded structure and generate hot melting connection. The thermal stress can be released in the printing process through the segmented design of the printed piece, and buckling deformation and cracking of the whole structure are reduced. According to the low-buckling-deformation 3D printing structure disclosed by the utility model, the connection force between the printing piece and the substrate is improved, and the buckling deformation of the printing piece can be effectively inhibited.

Description

TECHNICAL FIELD

[0001] The utility model belongs to 3D printing technical field, concretely relates to a 3D printing structure of low warping deformation. BACKGROUND

[0002] Fused deposition modeling (FDM) is a widely used polymer 3D printing forming technology. In recent years, with the continuous widening of the application field of FDM technology, FDM equipment has gradually developed from traditional desktop devices to large-size and high-efficiency industrial devices (the forming size is greater than 1 meter). For industrial FDM equipment, the material enters the inside of the printing head through the feeding pipe and is heated to a molten state in the inside of the printing head. Through the rotation of the screw, the molten material is extruded, and at the same time, the printing head moves according to the planned slicing path, so that the molten material is stacked layer by layer according to the specific path, and finally the required printing product is formed.

[0003] Based on the process principle of FDM technology, the material is quickly cooled and solidified after being extruded at high temperature, which determines that there is a large temperature difference before and after the material is extruded, so there is a certain shrinkage and internal stress, which causes the warping deformation and cracking of the printed part, and even the warping deformation of the printed part interferes with the movement of the printer nozzle and affects the smooth progress of the printing process. Moreover, in the printing process of industrial large-size parts, the thermal stress accumulates more seriously, so the warping deformation and cracking problem is particularly serious, which leads to poor size accuracy of the printed part, affects the subsequent subtractive machining and assembly process, and limits the engineering application of FDM technology in high-precision occasions. Therefore, controlling the warping deformation and cracking of FDM printed parts has important practical application value for widening the application field of FDM.

[0004] In order to solve the warping deformation and cracking problem in the printing process of FDM equipment, the technical personnel generally adopts the methods of improving the overall temperature of the printing chamber, locally heating the printed part, mechanically fixing the first layer of printing, using flexible particle substrate with the same printing material, etc. However, the above methods are more obvious for small-size printed parts and materials with low shrinkage rate, but the effect is very limited for large-size printed parts (the forming size is greater than 1m) and materials with high shrinkage rate. Moreover, for industrial FDM equipment, the overall temperature of the printing chamber is high in cost, the operation difficulty of mechanically fixing the first layer of printing is large, and the manufacturing cost of flexible particle substrate used as consumables is also relatively high. INVENTION CONTENTS

[0005] In order to overcome the above-mentioned existing FDM equipment printing large size printing piece prone to warping deformation and cracking and other technical defects, the utility model provides a kind of 3D printing structure of low warping deformation, this structure can effectively inhibit the warping deformation of printing piece.

[0006] In order to achieve the above-mentioned purpose, the utility model adopts the following technical solutions to be realized:

[0007] The utility model provides a kind of 3D printing structure of low warping deformation, including the printing substrate and printing piece of same material;Printing substrate is perforated plate, and a plurality of through holes are distributed on the surface of printing substrate plate;

[0008] Printing piece has at least two printing sections in growth direction;The first splicing portion of the lower surface of the first printing section of printing piece is protruding block, and the first splicing portion is inserted into the through hole of the surface of printing substrate plate and is fused;The second splicing portion of the upper surface of the first printing section is counterbore, and the second splicing portion is inserted into the lower surface of the second printing section of printing piece and is fused.

[0009] Further, the thickness of printing substrate is 2-5mm;The center distance between adjacent two through holes on the surface of plate is 6-20mm;The diameter of each through hole is 3-10mm.

[0010] Further, the height of each printing section is 20-500mm. Printing piece is any structure, according to the shrinkage of different printing materials, the height of each section is 20-500mm, the section height of material with small shrinkage is higher, and the section height of material with large shrinkage is low.

[0011] Further, the lower surface of the second printing section has the third splicing portion, the third splicing portion is protruding block, the third splicing portion protruding block is inserted into the counterbore of the second splicing portion and is fused.

[0012] Further, the upper surface of the second printing section has the fourth splicing portion, and the fourth splicing portion is counterbore, which is inserted into the lower surface of the third printing section of printing piece and is fused.

[0013] Further, the counterbore of the second splicing portion and the counterbore of the fourth splicing portion are independently rectangular, triangular, circular, trapezoidal, hexagonal or pentagonal in cross section. The depth of the counterbore is 2-5mm, the hole spacing is 6-20mm, and the inner diameter is 3-10mm.

[0014] Further, the through hole is a cylindrical hole.

[0015] Optionally, the through hole on the surface of printing substrate plate is a tapered hole, and the hole diameter on the upper surface of printing substrate r 1 is greater than the hole diameter on the lower surface of printing substrate r 2.

[0016] Further optionally, the through hole of the printing substrate plate surface is an inclined hole, and an angle between a longitudinal axis of the inclined hole and a thickness direction of the printing substrate is less than 45 degrees.

[0017] The printing substrate and the printed part are made of pure plastic or modified plastic.

[0018] Specifically, PP, ABS, PLA, PETG, PC, PA or PEEK can be optionally used.

[0019] Compared with the prior art, the printing substrate has the following beneficial effects:

[0020] The printing substrate is made of a porous plate with the same material as the printing material, and the first layer is bonded by traditional thermal fusion, and the embedded structure formed by the molten material into the hole of the substrate during printing of the first layer further improves the connection force of the first layer, improves the connection force of the printed part and the substrate, and can inhibit the warping deformation of the printed part; the entire printing substrate does not need to be heated during printing, and the printed part and the printing substrate can be directly mechanically peeled off, and the separation operation is simple and energy-saving.

[0021] The printed part is designed and printed in sections, and the accumulated thermal stress is gradually released after printing each section, reducing the warping deformation and cracking of the printed part caused by the accumulation of thermal stress. The thermal fusion and embedded structure between every two sections can ensure the interlayer bonding strength of the connection part, and the embedded structure can also inhibit the warping deformation of the upper part.

[0022] The first printing section and the printing substrate are connected by mortise and tenon embedded connection, and when external force or internal thermal stress acts on the connection part, the stress is dispersed to the entire connection surface through the embedded structure of the hole, so that the connection part can withstand greater load, reducing the possibility of stress concentration and deformation, effectively resisting deformation and maintaining the stability and accuracy of the connection. At the same time, due to the dispersion of stress and the increase of connection strength, the possibility of overall deformation of the connection part is also significantly reduced, which has a good inhibitory effect on the warping deformation of the segmented printing process. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 It is a whole schematic view of the printed part of the utility model;

[0024] Figure 2 It is an exploded view of the structure of the printed part of the utility model;

[0025] Figure 3 It is a structure cross-sectional view of the printed part of the utility model.

[0026] Wherein, 1-printing substrate; 2-the first printing section; 3-the second printing section; 4-the third printing section; 11-penetration hole; 21-the first splicing part; 22-the second splicing part; 31-the third splicing part; 32-the fourth splicing part; 41-the fifth splicing part. DETAILED DESCRIPTION

[0027] In order to make the person skilled in the art better understand the utility model scheme, the technical scheme in the utility model embodiments will be clearly and completely described below in conjunction with the drawings in the utility model embodiments. Obviously, the described embodiments are only a part of the embodiments of the utility model, not all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by the person skilled in the art without creative labor should belong to the protection scope of the utility model.

[0028] It should be noted that in the description of the utility model, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the utility model and simplifying the description, and does not indicate or imply that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, therefore it cannot be understood as a limitation on the utility model; the terms "first", "second", "third" are only for the purpose of description, and cannot be understood as indicating or implying relative importance; in addition, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixed connection, can also be detachable connection; it can be directly connected, also can be indirectly connected through intermediate medium, can be the communication inside two elements. For the person skilled in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.

[0029] The utility model will be further described in detail below in conjunction with the drawings:

[0030] The utility model discloses a kind of 3D printing structures of low warping deformation, referring to Figure 1 , including printing substrate 1 and printing piece, printing substrate 1 is the same porous plate as printing material material quality, printing substrate 1 and printing piece bottom rely on the embedded structure formed when printing first printing section 2 first layer molten material enters the penetration hole 11 of substrate and the hot fusion of printing material to realize connection.The structure of printing piece is segmented along printing growth direction, i.e.

[0031] The printed part can be of any structure, and the height of each printed segment is 20-500 mm according to the shrinkage of different printing materials. The height of the segment is higher for the material with smaller shrinkage, and the height of the segment is lower for the material with larger shrinkage. The diameter of the cylindrical hole distributed on each segment is 3-10 mm, the hole depth is 2-5 mm, and the hole spacing is 6-20 mm.

[0032] The printing substrate 1 is a through-hole plate with the same material as the printing material, the diameter of the through-hole is 3-10 mm, the thickness of the through-hole plate is 2-5 mm, and the spacing of the through-hole is 6-20 mm.

[0033] Embodiment

[0034] (1) A PP material printed part with three printed segments is to be printed;

[0035] (2) A through-hole printing substrate 1 is made of PP material, the diameter of the through-hole 11 of the printing substrate 1 is 5 mm, the thickness of the printing substrate 1 is 3 mm, and the distance between the centers of two adjacent through-holes 11 is 10 mm;

[0036] (3) The printing material PP is loaded into the feeding system of the 3D printer, and it is ensured that the PP enters the printing nozzle smoothly;

[0037] (4) The 3D printer heats the PP consumables to a molten state;

[0038] (5) The consumables PP are extruded through the nozzle and accumulated layer by layer along the path set by the computer to form the shape of each layer. The molten PP material enters the hole of the printing substrate to form the first splicing part 21, and the first splicing part 21 and the through-hole 11 form a mortise and tenon splicing and fitting structure and thermal fusion occurs. After each layer is completed, the workbench of the 3D printer is lowered by one layer height or the printing head is raised by one layer height, and the nozzle scans and extrudes the next layer section;

[0039] (6) Repeat the above steps to print the last layer of the first printed segment 2, and the height of the first printed part reaches 97 mm. According to the computer setting, the cylindrical hole with a diameter of 5 mm and a depth of 3 mm is printed to form the second splicing part 22 of the first printed segment 2. The height of the first printed segment 2 is 100 mm after printing is completed;

[0040] (7) After the last layer of the first printed segment cools to the glass transition temperature of the printing material, the second printed segment 3 is continued to be printed. According to the computer setting, the cylindrical boss structure with a diameter of 5 mm and a depth of 3 mm is printed to form the third splicing part 31 of the second printed segment 3, and the third splicing part 31 and the second splicing part 22 form a mortise and tenon splicing and fitting structure and thermal fusion occurs. After each layer is completed, the workbench of the 3D printer is lowered by one layer height or the printing head is raised by one layer height, and the nozzle scans and extrudes the next layer section;

[0041] (8) so repeatedly layer by layer deposition, until the last layer of the second printing segment 3, at this time the second printing piece height reaches 97mm, according to the computer set diameter of 5mm, depth of 3mm cylindrical counterbore, print the fourth splice 32 of the second printing segment 2. After the second printing segment 3 is printed, the height is 100mm;

[0042] (9) after the last layer of the first printing segment cools to the glass transition temperature of the printing material, continue to print the third printing segment 4. According to the computer set diameter of 5mm, depth of 3mm cylindrical boss structure, print the fifth splice 41 of the third printing segment 4, the fifth splice 41 and the fourth splice 32 form a mortise and tenon splice structure, and thermal fusion occurs; every time a layer is completed, the workbench of the 3D printer is lowered by one layer height or the print head is raised by one layer height, and the nozzle scans the next layer section and extrudes the filament, until the printing is completed, at this time the third printing piece height reaches 100mm.

[0043] (10) after printing, wait for the printing piece to cool down, take the printing piece and the printing substrate 1 from the printing platform, mechanically separate the printing piece from the printing substrate 1, and use sandpaper or a sander to trim the printing piece to make its surface smoother.

[0044] The above only describes the preferred embodiments of the present application, and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A low warping 3D printed structure, characterized in that, The printing substrate (1) and the printed part are made of the same material; the printing substrate (1) is a multi-hole plate, and a plurality of through holes (11) are distributed on the plate surface of the printing substrate (1); The printed part has at least two printed sections in the growth direction; the first printed section (2) has a first splicing part (21) on the lower surface, which is a protrusion and is spliced and inserted with the through hole (11) on the plate surface of the printing substrate (1); the upper surface of the first printed section (2) has a second splicing part (22), which is a counterbore and is spliced and inserted with the lower surface of the second printed section (3) of the printed part.

2. The low warping deformation 3D printed structure of claim 1, wherein, The thickness of the printing substrate (1) is 2-5 mm; the center distance between two adjacent through holes (11) on the plate surface is 6-20 mm; and the diameter of each through hole (11) is 3-10 mm.

3. The low warping deformation 3D printed structure of claim 1, wherein, The height of the printed section of the printed part is 20-500 mm.

4. The low warping deformation 3D printed structure of claim 1, wherein, The lower surface of the second printed section (3) has a third splicing part (31), which is a protrusion and is spliced and inserted with the counterbore of the second splicing part (22).

5. The low warpage 3D printed structure of claim 1 or claim 4, wherein, The upper surface of the second printed section (3) has a fourth splicing part (32), which is a counterbore and is spliced and inserted with the lower surface of the third printed section (4) of the printed part.

6. The low warping 3D printed structure of claim 5, wherein, The cross section of the counterbores of the second splicing part (22) and the fourth splicing part (32) is independently one of rectangular, triangular, circular, trapezoidal, hexagonal, and pentagonal.

7. The low warpage 3D printed structure of claim 1, wherein, The through hole (11) is a cylindrical hole.

8. The low warpage 3D printed structure of claim 1, wherein, The through hole (11) is a tapered hole, the hole diameter at the upper surface of the printing substrate r 1 is greater than the hole diameter at the lower surface of the printing substrate r 2.

9. The low warpage 3D printed structure of claim 1, wherein, The through hole (11) is an inclined hole, and the angle between the longitudinal axis of the inclined hole and the thickness direction of the printing substrate is less than 45°.

10. The low warpage 3D printed structure of any one of claims 1-9, wherein, The printing substrate (1) and the printed part are made of pure plastic or modified plastic.

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