3D printing method, variable height cylinder and 3D printer

Abstract

The present invention discloses a 3D printing method, a variable height cylinder and a 3D printer. The 3D printing method, the variable height cylinder, includes layer-by-layer printing of a printed part. During the layer-by-layer printing process of the printed part, the method further includes printing an annular closed wall on the periphery of the printed part, wherein the wall increases in thickness with increasing height of the printed part. The variable height cylinder includes a base, a connecting ring and a top plate. The top of the connecting ring is fixedly connected to the top plate, and the bottom is telescopically and sealedly connected to the base, and can be telescopically and sealedly connected to the outer wall of the wall after printing the wall. A printing hole is formed on the top plate, and the top of the base and the inner cavity of the connecting ring constitute the printing area. The 3D printer includes a variable height cylinder. The beneficial effect of the present invention is that the wall is used as a part of the cylinder for printing small molded parts in a large printer, so that the cylinder forms a variable height cylinder that changes with the height of the printed part, and the cylinder of this structure has versatility, saving printing costs.

Description

Technical Field

[0001] The present invention relates to 3D printing technology, in particular to a 3D printing method, a variable height cylinder and a 3D printer. Background Art

[0002] Selective laser melting (SLM) metal 3D printing involves melting layers of metal powder to create a finished part. Each time a layer is melted, the melting platform descends, and a new layer of powder is applied to the new layer, repeating the melting process. This process repeats to create the finished part.

[0003] Currently, printing small molded parts is done by installing a precision sleeve cylinder and setting a powder scraping mechanism on the sleeve cylinder. The powder scraping mechanism rotates back and forth to scrape the powder in the powder supply cylinder into the molding cylinder. Small molded parts are printed in the precision sleeve cylinder using components such as lasers in large-scale 3D metal printing equipment. Because the height and size of the precision sleeve cylinder are fixed, if you want to print thin and tall molded parts, you need to increase the height of the precision sleeve cylinder and reduce the molding space of the precision sleeve cylinder to save printing powder. Molded parts of different sizes and structures require customized corresponding precision sleeve cylinders. Due to the complex structure of the precision sleeve cylinder, the large number of parts, and the high production cost, the cost of printing molded parts is high. In addition, the precision sleeve cylinder takes up a large space in the 3D metal printer, resulting in low versatility of the precision sleeve cylinder. Therefore, improvements are needed. Summary of the Invention

[0004] The first purpose of the present invention is to address the shortcomings of existing printing methods, which require a specially matched precision sleeve when printing small molded parts using large printers, making them unsuitable for printing tall and slender molded parts. This method provides a 3D printing method that prints a closed wall around the periphery of the printed part during the layer-by-layer printing process. The wall increases in thickness as the height of the printed part increases. As the wall continues to rise, it forms a portion of the sleeve, thereby forming a variable height sleeve that changes with the height of the printed part. The second purpose of the present invention is to provide a variable height sleeve.

[0005] To achieve the first purpose, the present invention adopts the following technical solution.

[0006] A 3D printing method includes layer-by-layer printing of a printed part. During the layer-by-layer printing process of the printed part, the method further includes printing an annular closed wall on the periphery of the printed part, wherein the wall increases in thickness as the height of the printed part increases.

[0007] The 3D printing method employing the aforementioned technical solution prints a closed, annular wall around the periphery of the printed part as the height increases layer by layer. This wall increases in sync with the height of the printed part, maintaining the same height as the printed part. Consequently, the wall can be used as part of a cylinder used in large printers to print small parts, creating a variable-height cylinder that changes with the height of the printed part. This makes the cylinder structure universal, eliminating the need for specialized cylinders for parts of varying heights, effectively saving printing costs.

[0008] To achieve the second purpose, the present invention adopts the following technical solution.

[0009] A variable-height sleeve cylinder is used to seal a printing area during the printing process of a 3D printing method for achieving the first purpose; it comprises a base, a connecting ring and a top plate, the top of the connecting ring being fixedly connected to the top plate, the bottom being telescopically and sealingly connected to the base, and capable of being telescopically and sealingly connected to the outer wall of the wall after the wall is printed; a printing hole is formed on the top plate, and the top of the base and the inner cavity of the connecting ring constitute the printing area.

[0010] The variable height sleeve cylinder adopts the above-mentioned technical solution. By providing a base, a connecting ring and a top plate, the top of the connecting ring is fixedly connected to the top plate, and the bottom is telescopically and sealedly connected to the base. A printing hole is formed on the top plate. The top of the base and the inner cavity of the connecting ring constitute a printing area, so that prints can be printed in the printing area. When in use, the top plate is fixedly connected to the bottom of the printer's molding chamber, and the base is fixedly connected to the bottom of the printer's frame to form the printer's molding cylinder, and the printer's printing and powder spreading components are utilized. The first layer of the print is printed on the base, and in the same working cycle as printing the first layer of prints, a wall is printed at the outermost edge of the printing area, surrounding the print and having the same height as the print. As the printing height continues to increase, the connecting ring, which is telescopically and sealedly connected to the base, gradually detaches from the base during the rising process of the molding chamber and forms a telescopic and sealed connection with the printed wall, ensuring the sealing effect of the printing area. This allows the molding cylinder to be used to print molded parts of different heights without being restricted by the height of the printed molded parts, making it versatile. This variable-height sleeve boasts a simple structure and components, resulting in low production costs. It can replace multiple precision sleeves that differ only in height, improving versatility and reducing sleeve costs. It inherits the advantages of precision sleeves, such as the ability to customize the size of printed parts, reducing costs, and avoiding metal powder waste, significantly enhancing competitiveness.

[0011] Preferably, the cross-section of the connecting ring is an elliptical ring or a circular ring as a whole.

[0012] In this way, by setting the connecting ring to be oval or circular, it is convenient to maximize the utilization of the space inside the connecting ring, thereby further avoiding powder waste.

[0013] Preferably, a boss is formed on the top of the base, and the boss is slidably and sealingly connected to the inner side of the connecting ring; the outer wall surface of the wall is coplanar with the outer wall surface of the boss.

[0014] By providing a boss on the base and connecting the boss to the connecting ring, the connecting ring can form a good seal with the base during the initial printing process. The outer wall surface of the enclosure and the outer wall surface of the boss are coplanar, which can maintain the sealing performance of the cylinder during the sealing process of the enclosure after the connecting ring is separated from the boss.

[0015] Preferably, a sealing groove is provided on the inner side of the connecting ring that cooperates with the boss, and a wool felt seal and a sealing ring are installed side by side in the sealing groove; the outer wall surface of the boss and the outer wall surface of the wall can form a dynamic sealing connection with the connecting ring through the wool felt seal and the sealing ring.

[0016] In this way, by setting a sealing groove on the inner side of the connecting ring and installing the wool felt seal and the sealing ring side by side in the sealing groove, the wool felt seal and the sealing ring work together to form a sealing element to ensure the sealing of the printing area.

[0017] Preferably, a support ear is formed on the base, and a mounting hole is formed on the support ear, and a base locking screw passes through the mounting hole to be fixedly connected to the bottom plate of the printer frame.

[0018] In this way, by forming the support ears on the base and forming the mounting holes on the support ears, it is convenient to fix the base to the bottom plate of the printer frame, and the strength and rigidity of the connection point can be guaranteed.

[0019] Preferably, a top plate connecting flange is formed on the outer periphery of the top plate, and the top plate connecting flange is used to connect the top plate to the bottom of the molding chamber of the printer.

[0020] In this way, a top plate connecting flange is formed on the outer periphery of the top plate, and the top plate connecting flange is fixedly connected to the bottom of the molding chamber by bolts to ensure the strength and rigidity of the connection point.

[0021] Preferably, the top plate protrudes from the top plate connecting flange, and the top plate is used to be embedded in the bottom of the printer molding chamber.

[0022] In this way, by protruding the top plate from the top plate connecting flange, the top plate is embedded in the bottom of the molding chamber, and the top plate is positioned to ensure the position accuracy of the connecting ring connected to the top plate, so that the laser can smoothly enter the printing area and ensure the molding quality of the molded part.

[0023] Preferably, the printing hole is smaller than the inner diameter of the connecting ring.

[0024] By making the printed hole smaller than the inside diameter of the connecting ring, installation of the connecting ring is facilitated.

[0025] The present invention also provides a 3D printer comprising the above-mentioned variable height cylinder.

[0026] The beneficial effect of the present invention is that the printing method forms a perimeter wall around the printed part, which increases in thickness with increasing height. This wall can be used to configure the cylinder sleeve to have a variable height. This variable-height cylinder sleeve can replace multiple precision cylinder sleeves that differ only in height, reducing the cost of using the sleeve. It also inherits the advantages of precision cylinder sleeves, such as the ability to customize the size of the printed part, reducing the cost of printed parts, and avoiding metal powder waste, significantly improving competitiveness. The printer shares the same advantages as the aforementioned cylinder sleeve. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a three-dimensional structural diagram of the present invention;

[0028] Figure 2 It is a front view of the present invention;

[0029] Figure 3 This invention Figure 2 Cross-sectional view of AA. DETAILED DESCRIPTION

[0030] The present invention will be further described below with reference to the accompanying drawings, but the present invention is not limited to the scope of the embodiments described.

[0031] The reference numerals in the drawings of the specification include: base 1, support ear 11, boss 2, connecting ring 3, top plate connecting flange 4, top plate 5, printing hole 51, wool felt seal 6, sealing ring 7, base locking screw 8.

[0032] Example 1, a 3D printing method, includes printing a printed part layer by layer. During the layer-by-layer printing process, the method further includes printing a closed annular wall around the periphery of the printed part, wherein the wall increases in thickness with increasing height of the printed part. The wall forms a portion of a cylinder, thereby forming a variable-height cylinder that changes with the height of the printed part.

[0033] Example 2, see Figures 1 to 3A variable-height sleeve cylinder is used to seal the printing area during the printing process of the 3D printing method. It includes a base 1, a connecting ring 3, and a top plate 5. The top of the connecting ring 3 is fixedly connected to the top plate 5, and the bottom is telescopically and sealedly connected to the base 1. After the wall is printed, it can be telescopically and sealedly connected to the outer wall of the wall. The top plate 5 is formed with a printing hole 51. The top of the base 1 and the inner cavity of the connecting ring 3 constitute the printing area. This variable-height sleeve cylinder has a simple structure and component structure. The production cost of the variable-height sleeve cylinder is low, and it can be customized according to the size of the printed part, avoiding the waste of metal powder, especially precious metal powder.

[0034] Among them, see Figure 1 The cross-section of the connecting ring 3 is generally elliptical or circular. A boss 2 is formed on the top of the base 1, and the boss 2 is in sliding and sealing connection with the inner side of the connecting ring 3; the outer wall surface of the enclosure is coplanar with the outer wall surface of the boss 2. By providing the boss 2 on the base and connecting the boss 2 to the connecting ring 3, the connecting ring 3 can form a good seal with the base 1 in the initial stage of printing. The coplanarity of the outer wall surface of the enclosure and the outer wall surface of the boss 2 can maintain the sealing performance of the cylinder sleeve unchanged during the sealing process of the enclosure after the connecting ring 3 is separated from the boss 2.

[0035] Other slidable structures may also be provided to achieve the above-mentioned sliding connection function.

[0036] See also Figure 1 The inner side of the connecting ring 3, where it mates with the boss 2, is provided with a sealing groove. A wool felt seal 6 and a sealing ring 7 are installed side by side within the sealing groove. The outer wall of the boss 2 and the outer wall of the enclosure both form a dynamic sealing connection with the connecting ring 3 through the wool felt seal 6 and sealing ring 7. This ensures that the connecting ring 3 is sealed to the base 1 during the initial printing phase, ensuring a tight seal within the printing area.

[0037] See also Figure 1 A lug 11 is formed on the base 1, and a mounting hole is formed on the lug 11. The base locking screw 8 passes through the mounting hole and is fixedly connected to the bottom plate of the 3D printer frame to ensure the strength and rigidity of the connection point.

[0038] See also Figure 1 The top plate 5 is provided with a top plate connecting flange 4 on its outer periphery. The top plate connecting flange 4 is used to connect the top plate 5 to the bottom of the molding chamber of the printer to ensure the strength and rigidity of the connection point.

[0039] See also Figure 1 The top plate 5 protrudes from the top plate connecting flange 4 and is embedded in the bottom of the printer's molding chamber. This ensures the positional accuracy of the connecting ring 3 connected to the top plate 5 and the molding quality of the molded part. The printing hole 51 is smaller than the inner diameter of the connecting ring 3.

[0040] During the printing process, the print is first printed in the printing area, and at the same time, a wall equal to the height of the print is printed on the outermost edge of the printing area. As the printing height continues to increase, the connecting ring 3 slidably connected to the base 1 gradually separates from the chuck of the base 1 during the rising process of the molding chamber and connects with the printed wall to ensure the sealing effect of the printing area. During the entire printing process, the bottom end of the connecting ring 3 is always at a position lower than the height of the molded part, so that the Z-axis movable seal with the wall can be achieved throughout the process until the printing is completed.

[0041] Example 3, a 3D printer, comprising the above-mentioned variable height cylinder.

[0042] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A variable height cylinder, used to print a closed annular wall around the periphery of a printed part during layer-by-layer printing of the printed part, wherein the wall increases in thickness with increasing height of the printed part, thereby achieving a closed printing area, characterized in that: The invention comprises a base (1), a connecting ring (3) and a top plate (5), wherein the top of the connecting ring (3) is fixedly connected to the top plate (5), and the bottom is telescopically and sealedly connected to the base (1), and can be telescopically and sealedly connected to the outer wall of the wall after the wall is printed; a printing hole (51) is formed on the top plate (5), and the top of the base (1) and the inner cavity of the connecting ring (3) constitute the printing area; a boss (2) is formed on the top of the base (1), and the boss (2) is slidably and sealedly connected to the inner side of the connecting ring (3); the outer wall surface of the wall and the outer wall surface of the boss (2) are coplanar; a support ear (11) is formed on the base (1), and a mounting hole is formed on the support ear (11), and a base locking screw (8) passes through the mounting hole and is fixedly connected to the bottom plate of the 3D printer frame; a top plate connecting flange (4) is formed on the outer periphery of the top plate (5), and the top plate connecting flange (4) is used to connect the top plate (5) to the bottom of the molding chamber of the printer.

2. The variable height cylinder according to claim 1, characterized in that: The cross section of the connecting ring (3) is an elliptical ring or a circular ring as a whole.

3. The variable height cylinder according to claim 1, characterized in that: A sealing groove is provided on the inner side of the connecting ring (3) and the boss (2), in which a wool felt seal (6) and a sealing ring (7) are installed side by side. The outer wall surface of the boss (2) and the outer wall surface of the enclosure can form a dynamic sealing connection with the connecting ring (3) through the wool felt seal (6) and the sealing ring (7).

4. The variable height cylinder according to claim 1, characterized in that: The top plate (5) protrudes from the top plate connecting flange (4), and the top plate (5) is embedded in the bottom of the molding chamber of the printer.

5. The variable height cylinder according to any one of claims 1 to 4, characterized in that: The printing hole (51) is smaller than the inner diameter of the connecting ring (3).

6. A 3D printer, characterized in that: The invention comprises the variable height cylinder according to any one of claims 1 to 5.

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