Additive manufacturing breadth expansion device and expansion method for selective laser melting

Abstract

The invention discloses an additive manufacturing breadth expanding device for selective laser melting and an expanding method. The device comprises a working platform, a base plate mounting surface cover plate, an original size forming cylinder, a limiting cylinder body supporting column, a ball screw pair, a driving mechanism, an expanding mounting surface cover plate, an expanding forming cylinder and a limiting plate. The original size forming cylinder and the multiple expansion forming cylinders are located on the upper portion in the working platform side by side, the bottom faces of the original size forming cylinder and the expansion forming cylinders are fixedly connected with limiting cylinder body supporting columns, and limiting blocks are arranged at the bottom ends of the limiting cylinder body supporting columns. The driving mechanism comprises a main driving motor and a positioning pin driving motor; the main driving motor is mounted on a bottom plate of the working platform, and the driving mechanism is connected with the original-size forming cylinder through a ball screw pair; the positioning pin driving motor is fixed to the bottom face of the original-size forming cylinder, and the main driving motor and the positioning pin driving motor are matched to drive the original-size forming cylinder and the expansion forming cylinder to move synchronously. The powder spreading range can be flexibly selected and adjusted according to the section size requirement.

Description

Technical Field

[0001] The present invention relates to the field of metal additive manufacturing, and in particular to an additive manufacturing format expansion device and expansion method for selective laser melting. Background Art

[0002] Selective laser melting (SLM) technology is a metal additive manufacturing technology that uses laser to selectively melt pre-laid powder according to a sliced ​​computer-aided design model. The scanned metal powder is melted and solidified to achieve a metallurgical bonding effect, and finally the metal parts designed by the model are obtained.

[0003] In metal laser selective melting forming equipment, the current forming format size ranges from small decimeter level to large meter level. Models of different sizes require the replacement of printers with corresponding format sizes. When large meter-level printers are used to manufacture small-sized models, it will undoubtedly cause redundancy and waste of metal powder.

[0004] However, the current additive manufacturing formats of existing printers all adopt an integrated design and are used as fixed parts. In the molding chamber, the scraper first spreads powder along the preset substrate - laser sintering - and returns to spread powder. When the model size exceeds the molding format, another printer of the corresponding size must be found for processing, resulting in an increase in manufacturing costs; when the model size is much smaller than the molding format, a much larger amount of powder is required, increasing the risk of material waste.

[0005] In summary, there is currently a lack of a simple, reliable and cost-saving method to address the problem of mismatched additive format sizes, resulting in material waste and cost increases. Summary of the invention

[0006] In view of the shortcomings of the prior art, the present invention provides an additive manufacturing format expansion device and expansion method for selective laser melting, and the specific technical scheme is as follows:

[0007] An additive manufacturing format expansion device for selective laser melting, comprising a working platform, a base plate mounting surface cover, an original size molding cylinder, a limit cylinder support column, a ball screw pair, a driving mechanism, an expansion mounting surface cover, an expansion molding cylinder and a limit plate;

[0008] The working platform is a vertical frame fixed inside the laser selective melting printer, the bottom of the working platform is in direct contact with the ground, and the upper surface is in the printer molding chamber; the top surface of the working platform is a substrate mounting surface, which is used to support multi-size printing substrates; the substrate mounting surface is grooved, and the substrate mounting surface cover plate and the extended mounting surface cover plate cover the grooves of the substrate mounting surface;

[0009] The original size forming cylinder and several extended forming cylinders are arranged in parallel above the inside of the working platform, and several extended forming cylinders are arranged on one side of the original size forming cylinder; the bottom surfaces of the original size forming cylinder and the extended forming cylinder are fixedly connected to one end of the limit cylinder support column; the limit plate is fixedly connected to the middle part of the working platform, and the limit cylinder support column passes through the through hole on the working platform; a limit block is arranged at the bottom end of the limit cylinder support column;

[0010] The driving mechanism includes a main driving motor, a positioning pin driving motor, a positioning pin and a lifting lug; the main driving motor is installed on the bottom plate of the working platform, and the driving mechanism is connected to the original size forming cylinder through the ball screw pair; the positioning pin driving motor is fixed on the bottom surface of the original size forming cylinder, and the lifting lugs are multiple and respectively fixed to the original size forming cylinder and the expansion forming cylinder, and the lifting lugs are provided with pin holes, and all the pin holes are coaxial, one end of the positioning pin is connected to the positioning pin driving motor, and the other end passes through the pin hole, so that the original size forming cylinder and the corresponding expansion forming cylinder move synchronously.

[0011] Furthermore, there are four limit cylinder support columns at the bottom of the original-size forming cylinder, which are respectively fixedly connected to the four corners of the original-size forming cylinder.

[0012] Furthermore, there is one limiting cylinder support column at the bottom of each expansion molding cylinder, which is fixedly connected to the middle part of the bottom surface of the expansion molding cylinder.

[0013] Furthermore, the base mounting surface cover plate and the extended mounting surface cover plate have a total of multiple sets of matching specifications, so as to adapt to the original size molding cylinder and different numbers of extended molding cylinders for combined printing.

[0014] A method for expanding the format of additive manufacturing for selective laser melting is implemented based on an additive manufacturing format expansion device for selective laser melting. The method comprises the following steps:

[0015] When you only need to print using the original format:

[0016] (1) The computer built into the selective laser melting printer issues a command to cause the main drive motor to control the ball screw pair to move, and the ball screw pair drives the original-size forming cylinder to move upward until the top surface of the original-size forming cylinder is flush with the base plate mounting surface of the working platform;

[0017] (2) removing the substrate mounting surface cover, installing the original-size printing substrate, issuing instructions through the computer to move the ball screw pair downward, and finely adjusting until the original-size printing substrate is flush with the substrate mounting surface of the working platform. After normal pre-printing processing including substrate heating, the printer starts the normal 3D printing process;

[0018] When you need to use extended format printing:

[0019] (1) The computer built into the selective laser melting printer issues a command to cause the main drive motor to control the ball screw pair to move, and the ball screw pair drives the original-size molding cylinder to move, so that the bottom surface of the original-size molding cylinder is flush with the bottom surface of the expansion molding cylinder to be matched, and the positioning pin drive motor drives the positioning pin to extend and retract, and the expansion molding cylinder to be moved is fixedly connected with the original-size molding cylinder through the positioning pin; the main drive motor continues to control the ball screw pair to move, and the ball screw pair drives the original-size molding cylinder and the matched expansion molding cylinder to move together until the top surface of the original-size molding cylinder is flush with the base mounting surface of the working platform;

[0020] (2) Replace the substrate mounting surface cover plate and the extended mounting surface cover plate to match the currently working original-size molding cylinder and the extended molding cylinder, replace the substrate mounting surface cover plate on the currently working original-size molding cylinder and the extended molding cylinder with the printing substrate, and retain the extended mounting surface cover plate on the non-working extended molding cylinder to prevent powder leakage from the gap during 3D printing;

[0021] (3) The computer sends a command to move the ball screw pair downward, and finely adjusts it until the printing substrate is flush with the upper surface of the work platform. After normal pre-printing processing including substrate heating, the printer starts the normal 3D printing process until printing is completed.

[0022] Furthermore, before installing the printing substrate, a heat insulation board or a powder leakage-proof felt board is first installed on the substrate installation surface.

[0023] The beneficial effects of the present invention are as follows:

[0024] The additive manufacturing width expansion device for selective laser melting of the present invention adopts a variable powder spreading width mechanism, which can flexibly select and adjust the powder spreading range according to the cross-sectional size requirements of a large cabin or a model to be manufactured, greatly optimizing the use efficiency of raw materials and avoiding the problem of material waste caused by over-paving or under-paving; and relying on the high accuracy of the powder spreading process, it reduces the manufacturing defects that may be caused by improper use of materials, thereby improving the overall quality of the product, reducing the cost of the entire manufacturing process and improving the economic benefits of production. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the overall structure of the format expansion device in an embodiment of the present invention.

[0026] Figure 2 It is a front structural schematic diagram of the format expansion device in an embodiment of the present invention.

[0027] Figure 3 It is a schematic diagram of the working limit operation of the format expansion device in an embodiment of the present invention.

[0028] Figure 4 It is a schematic diagram of the structure after the device format expansion is completed in an embodiment of the present invention.

[0029] In the figure, working platform 1, substrate mounting surface 1-1, substrate mounting surface cover plate 2, original size forming cylinder 3, limit cylinder support column 4, ball screw pair 5, driving mechanism 6, extended mounting surface cover plate 7, extended forming cylinder 8, limit plate 9, main driving motor 6-1, positioning pin driving motor 6-2, positioning pin 6-3, and lifting ear 6-4. DETAILED DESCRIPTION

[0030] The present invention will be described in detail below based on the accompanying drawings and preferred embodiments, and the purpose and effects of the present invention will become more clear. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0031] like Figure 1 and Figure 2 As shown, the format expansion device for additive manufacturing by selective laser melting of this embodiment includes a working platform 1, a substrate mounting surface cover plate 2, an original size forming cylinder 3, a limiting cylinder support column 4, a ball screw pair 5, a driving mechanism 6, an extended mounting surface cover plate 7, an extended forming cylinder 8 and a limiting plate 9. The working platform 1 is a vertical frame fixed inside the laser selective area melting printer. The bottom of the working platform 1 is in direct contact with the ground, and the upper surface is in the printer molding chamber. The top surface of the working platform 1 is a substrate mounting surface 1-1, which is used to support multi-size printing substrates. The substrate mounting surface 1-1 is grooved, and the substrate mounting surface cover plate 2 and the extended mounting surface cover plate 7 cover the groove of the substrate mounting surface 1-1.

[0032] The original-size forming cylinder 3 and several extended forming cylinders 8 are arranged side by side above the inside of the working platform 1, and the several extended forming cylinders 8 are all located on one side of the original-size forming cylinder 3. A limiting cylinder support column 4 is fixedly connected to each of the four corners of the bottom of the original-size forming cylinder 3, and two limiting cylinder support columns 4 are fixedly connected to the middle of the bottom surface of each extended forming cylinder 8. The limiting plate 9 is fixedly connected to the middle of the working platform 1 and is located below the original-size forming cylinder 3 and several extended forming cylinders 8. A through hole is provided on the limiting plate 9, and all the limiting cylinder support columns 4 pass through the through holes at the corresponding positions on the limiting plate 9, and there is a limiting block at the bottom end of the limiting cylinder support column 4. Figure 3 As shown, the limited cylinder support column 4 can move up and down with the corresponding cylinder, and its length can simultaneously ensure that the cylinder is supported at the bottom and the cylinder is limited at the top. When the expansion molding cylinder 8 is not connected to the original size molding cylinder 3, the expansion molding cylinder 8 is supported on the bottom plate of the working platform 1 by the limited cylinder support column 4.

[0033] like Figure 1 As shown, the ball screw pair 5 is arranged below the original size forming cylinder 3, as shown in FIG. Figure 2 As shown, the driving mechanism 6 includes a main driving motor 6-1, a positioning pin driving motor 6-2, a positioning pin 6-3 and a lifting lug 6-4. The main driving motor 6-1 is installed on the bottom plate of the working platform 1 and is located directly below the original size forming cylinder 3. One end of the ball screw pair 5 is connected to the main driving motor 6-1, and the other end is connected to the original size forming cylinder 3. The main driving motor 6-1 provides a driving power mode by receiving an electrical signal from a computer built into the selective laser melting printer, thereby controlling the rise and fall of the printed substrate. The positioning pin driving motor 6-2 is installed on the bottom surface of the original size forming cylinder 3. There are multiple lifting ears 6-4, which are respectively installed on the bottom surfaces of the original-size molding cylinder 3 and several expanded molding cylinders 8. Pin holes are opened on the lifting ears 6-4. The pin holes of all the lifting ears 6-4 are coaxial, so that one end of the positioning pin 6-3 can pass through the pin hole, and the other end is connected to the positioning pin driving motor 6-2. The positioning pin driving motor 6-2 drives the positioning pin 6-3 to pass through the corresponding pin hole on the expanded molding cylinder 8, thereby connecting the expanded molding cylinder 8 and the original-size molding cylinder 3, and realizing the synchronous up and down movement of the two cylinders.

[0034] In this embodiment, the number of extended forming cylinders can be adjusted according to the actual usage size, thereby adjusting the printing area size.

[0035] The base plate mounting surface cover plate 2 and the extended mounting surface cover plate 7 together constitute the upper cover plate of all the forming steels. Therefore, the base plate mounting surface cover plate 2 and the extended mounting surface cover plate 7 have a total of multiple sets of different specifications and sizes, so as to adapt to the original size forming cylinder 3 and different numbers of extended forming cylinders 8 for combined printing. Figure 4As shown, the base plate mounting surface cover plate 2 covers the original-size molding cylinder 3 and one extended molding cylinder 8 , and the extended mounting surface cover plate 7 covers the remaining two extended molding cylinders 8 .

[0036] This embodiment also provides a method for expanding the format of additive manufacturing for selective laser melting, comprising the following steps:

[0037] When you only need to print using the original format:

[0038] (1) The computer built into the selective laser melting printer sends a command to make the main drive motor 6-1 control the ball screw pair 5 to move, and the ball screw pair 5 drives the original size forming cylinder 3 to move upward until the top surface of the original size forming cylinder 3 is flush with the base plate mounting surface 1-1 of the working platform 1;

[0039] (2) Remove the substrate mounting surface cover 2, install the original-size printed substrate, issue a command through the computer to move the ball screw pair 5 downward, and finely adjust it until the original-size printed substrate is flush with the substrate mounting surface 1-1 of the working platform 1. After normal pre-printing processing including substrate heating, the printer starts the normal 3D printing process;

[0040] When you need to use extended format printing:

[0041] (1) The computer built into the selective laser melting printer sends a command to make the main drive motor 6-1 control the ball screw pair 5 to move, and the ball screw pair 5 drives the original size molding cylinder 3 to move, so that the bottom surface of the original size molding cylinder 3 is flush with the bottom surface of the expansion molding cylinder 8 to be matched, and the positioning pin drive motor 6-2 drives the positioning pin 6-3 to extend and retract, and the expansion molding cylinder 3-2 to be moved is fixedly connected with the original size molding cylinder 3-1 through the positioning pin 6-3; the main drive motor 6-1 continues to control the ball screw pair 5 to move, and the ball screw pair 5 drives the original size molding cylinder 3 and the matching expansion molding cylinder 3-2 to move together until the top surface of the original size molding cylinder 3 is flush with the base plate mounting surface 1-1 of the working platform 1;

[0042] (2) Replace the substrate mounting surface cover plate 2 and the extended mounting surface cover plate 7 to match the currently working original-size molding cylinder 3 and the extended molding cylinder 8. Replace the substrate mounting surface cover plate 2 on the currently working original-size molding cylinder 3 and the extended molding cylinder 8 with the printing substrate, and retain the extended mounting surface cover plate 7 on the non-working extended molding cylinder 8 to prevent powder leakage from the gap during 3D printing;

[0043] (3) The computer sends a command to move the ball screw pair 5 downward, and finely adjusts it until the printing substrate is flush with the upper surface of the work platform 1. After normal pre-printing processing including substrate heating, the printer starts the normal 3D printing process until printing is completed.

[0044] In addition, in order to avoid high temperature corrosion and powder leakage during 3D printing, before installing the printing substrate, you can also add a heat insulation board and a powder leakage-proof felt board on the substrate installation surface.

[0045] The present invention changes the size of the printing format by controlling the forming cylinder, thereby solving the problem of material waste and cost increase caused by the mismatch between the size of the forming format and the required size of the printed parts in the past metal laser selective melting forming equipment. It greatly reduces the material waste and cost increase problems existing in the process of replacing machines with multi-size formats, reduces the cost of the entire manufacturing process, and improves the economic benefits of production.

[0046] Those skilled in the art can understand that the above are only preferred examples of the invention and are not intended to limit the invention. Although the invention is described in detail with reference to the above examples, those skilled in the art can still modify the technical solutions recorded in the above examples or replace some of the technical features therein with equivalents. Any modification, equivalent replacement, etc. made within the spirit and principle of the invention shall be included in the protection scope of the invention.

Claims

1. An additive manufacturing format expansion device for selective laser melting, characterized in that: It comprises a working platform (1), a base plate mounting surface cover plate (2), an original size forming cylinder (3), a limiting cylinder support column (4), a ball screw pair (5), a driving mechanism (6), an extended mounting surface cover plate (7), an extended forming cylinder (8) and a limiting plate (9); The working platform (1) is a vertical frame fixed inside the laser selective area melting printer, the bottom of the working platform (1) is in direct contact with the ground, and the upper surface is in the printer molding chamber; the top surface of the working platform (1) is a substrate mounting surface (1-1) for supporting printed substrates of multiple sizes; A groove is formed on the substrate mounting surface (1-1), and the substrate mounting surface cover plate (2) and the extended mounting surface cover plate (7) cover the groove of the substrate mounting surface (1-1); The original-size forming cylinder (3) and a plurality of the extended forming cylinders (8) are located in parallel above the interior of the working platform (1), and the plurality of the extended forming cylinders (8) are located on one side of the original-size forming cylinder (3); the bottom surfaces of the original-size forming cylinder (3) and the extended forming cylinder (8) are both fixedly connected to one end of the limiting cylinder support column (4); the limiting plate (9) is fixedly connected to the middle of the working platform (1), and the limiting cylinder support column (4) passes through the through hole on the working platform (1); a limiting block is provided at the bottom end of the limiting cylinder support column (4); The driving mechanism (6) comprises a main driving motor (6-1), a positioning pin driving motor (6-2), a positioning pin (6-3) and a lifting lug (6-4); the main driving motor (6-1) is mounted on the bottom plate of the working platform (1), and the driving mechanism (6) is connected to the original-size molding cylinder (3) through the ball screw pair (5); the positioning pin driving motor (6-2) is fixed on the bottom surface of the original-size molding cylinder (3), and the lifting lug (6-4) is multiple and respectively fixed to the original-size molding cylinder (3) and the expansion molding cylinder (8), and the lifting lug (6-4) is provided with a pin hole, and all the pin holes are coaxial, and one end of the positioning pin (6-3) is connected to the positioning pin driving motor (6-2), and the other end passes through the pin hole, so that the original-size molding cylinder (3) and the corresponding expansion molding cylinder (8) move synchronously.

2. The additive manufacturing format expansion device for selective laser melting according to claim 1, characterized in that: There are four limit cylinder support columns (4) at the bottom of the original-size forming cylinder (3), which are respectively fixedly connected to the four corners of the original-size forming cylinder (3).

3. The additive manufacturing format expansion device for selective laser melting according to claim 1, characterized in that: The number of the limiting cylinder support columns (4) at the bottom of each expansion molding cylinder (8) is one and is fixedly connected to the middle of the bottom surface of the expansion molding cylinder (8).

4. The additive manufacturing format expansion device for selective laser melting according to claim 1, characterized in that: The base plate mounting surface cover plate (2) and the extended mounting surface cover plate (7) have a total of multiple sets of matching specifications, thereby adapting to the original size molding cylinder (3) and different numbers of extended molding cylinders (8) for combined printing.

5. A method for expanding the format of additive manufacturing for selective laser melting, characterized in that: The method is implemented based on the additive manufacturing format expansion device for selective laser melting according to claim 1, and the method comprises the following steps: When you only need to print using the original format: (1) The computer built into the selective laser melting printer issues a command to cause the main drive motor (6-1) to control the ball screw pair (5) to move, and the ball screw pair (5) drives the original-size forming cylinder (3) to move upward until the top surface of the original-size forming cylinder (3) is flush with the base plate mounting surface (1-1) of the working platform (1); (2) removing the substrate mounting surface cover plate (2), installing the original-size printing substrate, issuing instructions through a computer to move the ball screw pair (5) downward, and finely adjusting until the original-size printing substrate is flush with the substrate mounting surface (1-1) of the working platform (1), and after normal pre-printing processing including substrate heating, the printer starts a normal 3D printing process; When you need to use extended format printing: (1) The computer built into the selective laser melting printer issues a command to cause the main drive motor (6-1) to control the ball screw pair (5) to move, and the ball screw pair (5) drives the original size molding cylinder (3) to move, so that the bottom surface of the original size molding cylinder (3) is flush with the bottom surface of the expansion molding cylinder (8) to be matched, and the positioning pin drive motor (6-2) drives the positioning pin (6-3) to extend and retract, and the expansion molding cylinder (3-2) to be moved is fixedly connected to the original size molding cylinder (3-1) through the positioning pin (6-3); the main drive motor (6-1) continues to control the ball screw pair (5) to move, and the ball screw pair (5) drives the original size molding cylinder (3) and the matched expansion molding cylinder (3-2) to move together until the top surface of the original size molding cylinder (3) is flush with the base plate mounting surface (1-1) of the working platform (1); (2) replacing the substrate mounting surface cover plate (2) and the extended mounting surface cover plate (7) to match the original-size molding cylinder (3) and the extended molding cylinder (8) currently in operation, replacing the substrate mounting surface cover plate (2) on the original-size molding cylinder (3) and the extended molding cylinder (8) currently in operation with a printing substrate, and retaining the extended mounting surface cover plate (7) on the extended molding cylinder (8) not in operation, to prevent powder from leaking from the gap during the 3D printing process; (3) The computer sends a command to move the ball screw pair (5) downward, and finely adjusts it until the printing substrate is flush with the upper surface of the working platform (1). After normal pre-printing processing including substrate heating, the printer starts the normal 3D printing process until printing is completed.

6. The additive manufacturing format expansion method for selective laser melting according to claim 5, characterized in that: Before installing the printing base plate, install a heat insulation board or a powder leakage-proof felt board on the base plate installation surface.

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