Mechanically synchronized displacement system for very large SLM equipment

Abstract

The invention discloses a mechanical synchronous displacement system for super-large SLM equipment, comprising a frame, a forming cylinder and a galvanometer system installed on the frame, a displacement frame installed on the frame capable of horizontal transverse movement, and a translation drive system for driving the displacement frame to intermittent horizontal transverse movement. A powder scraping plane provided with a forming opening is arranged on the frame, an upper opening of the forming cylinder can be sealed and connected with the forming opening, a lower end of the displacement frame is in dynamic sealing contact with the powder scraping plane, an opening at the lower end of the displacement frame is directly opposite to an opening at the upper end of the forming cylinder, a scraper and a powder supply mechanism are fixedly arranged on at least one side wall of the displacement frame along its translation direction, an air inlet and an air suction port for inert gas to enter and exit are respectively arranged on two opposite side walls at the lower end of the displacement frame, and the galvanometer system can emit laser toward the powder at the lower end of the displacement frame. The invention simultaneously and coordinately completes the steps of powder supply, powder spreading, scanning and dust removal, has a simple structure, is easy to adjust and repair, is convenient to take out, and can adapt to the molding of products of various specifications and sizes.

Description

Technical Field

[0001] The present invention relates to the technical field of 3D laser printing, and in particular to a mechanical synchronous displacement system for super-large SLM equipment. Background Art

[0002] Melting processing has been carried out through SLM equipment for more than 20 years; the structure of traditional SLM equipment is a molding chamber fixedly installed on the frame at the top, a galvanometer system is arranged above the molding chamber, a molding cylinder is arranged below the molding chamber, a powder supply mechanism is arranged outside the molding chamber, a powder scraping plane is formed on the bottom surface of the molding chamber, a scraper is arranged in the molding chamber, and the molding chamber is filled with inert gas. During molding, the powder supply mechanism intermittently and quantitatively delivers metal powder to the surface on one side of the scraping plane, and the scraper scrapes the metal powder flat, and the metal powder is scraped into the opening of the molding cylinder, and the powder forms a layer of powder in the molding cylinder that is flush with the scraping plane. After the powder scraping is completed, the galvanometer system reflects the laser to make the molding cylinder The inner and upper layers of powder are melted and processed. After the processing is completed, the piston of the forming cylinder drops one layer height, and the aforementioned powder supply, powder scraping and processing melting steps are repeated. This cycle is repeated to finally form a workpiece. During the entire process of workpiece forming, the forming chamber is filled with inert gas, and dust is discharged to the outside through the dust exhaust port on the side wall of the forming chamber. After the workpiece is completed, the forming cylinder is moved horizontally to separate it from the forming chamber, and then the workpiece is taken out. This traditional laser melting process is complicated, and the powder supply, powder spreading, sweeping and dust removal are all independently controlled in sequence. The control procedure is cumbersome, the electronic control system is prone to failure, and the forming efficiency is low. The reliability and anti-interference ability of the entire system are poor, and it is inconvenient to repair faults and difficult to take out parts. Summary of the invention

[0003] In order to make up for the above shortcomings, the present invention provides a mechanical synchronous displacement system for ultra-large SLM equipment. The mechanical synchronous displacement system for ultra-large SLM equipment is controlled mainly by mechanical factors, has high reliability, strong anti-interference ability, simple structure, and is easy to adjust and repair.

[0004] The technical solution adopted by the present invention to solve its technical problems is: a mechanical synchronous displacement system for super-large SLM equipment, including a frame, a forming cylinder, a displacement frame, a galvanometer system and a translation drive system, a powder scraping plane is fixedly provided on the frame, a forming port is provided on the powder scraping plane, a forming cylinder is installed on the frame, an upper end opening of the forming cylinder can be sealed and connected with the forming port on the powder scraping plane, a piston in the forming cylinder can be moved downward in a dynamic and sealed manner, a displacement frame can be installed on the frame in a horizontal and transverse manner, the translation drive system drives the displacement frame to intermittently move horizontally, and the lower end of the displacement frame is in dynamic and sealed contact with the powder scraping plane The displacement frame has a bottom opening that is directly opposite to the top opening of the forming cylinder; a scraper and a powder supply mechanism are fixedly arranged on at least one side wall of the displacement frame along its translation direction; the powder supply mechanism can provide forming powder to the inside of the forming cylinder; the scraper can flatten the powder in the forming cylinder; an air inlet and an air suction port are respectively arranged on the two opposite side walls at the bottom of the displacement frame; the air inlet can deliver inert gas into the interior of the displacement frame; the air suction port can discharge the gas inside the displacement frame; a galvanometer system is fixedly installed on the top of the displacement frame; the galvanometer system can emit laser toward the powder in the forming cylinder directly opposite to the bottom opening of the displacement frame for melting processing.

[0005] As a further improvement of the invention, the translation drive system includes a servo motor, a reducer and a screw-nut mechanism, the servo motor and the reducer are fixedly mounted on a frame, the screw of the screw-nut mechanism is axially stopped and rotatable in a circumferential direction on the frame, the nut of the screw-nut mechanism is fixedly connected to the displacement frame, and the servo motor drives the screw of the screw-nut mechanism to rotate through the reducer.

[0006] As a further improvement of the invention, the frame is further provided with a horizontally extending linear guide rail, the displacement frame is provided with a slider, and the slider can be slidably mounted on the linear guide rail.

[0007] As a further improvement of the invention, scrapers and powder supply mechanisms are fixedly provided on two opposite side walls of the displacement frame along its translation direction.

[0008] As a further improvement of the invention, the translation distance of the displacement frame each time is smaller than the size of the opening at the lower end of the displacement frame along its translation direction.

[0009] As a further improvement of the invention, the displacement frame is a barrel-shaped structure with a light-transmitting upper end and an open lower end, and the lower end of the displacement frame is in dynamic sealing contact with the powder scraping plane through a sealing structure.

[0010] As a further improvement of the invention, the powder scraping plane is fixedly installed in the frame, and the powder scraping plane divides the frame into an upper box structure and a lower box structure. The displacement frame and the galvanometer system, powder supply system and scraper thereon are located in the upper box structure, and the forming cylinder is located in the lower box structure. The displacement frame can be moved to a position that is completely misaligned with the forming cylinder. A removal door is provided on the side wall of the upper box structure, and a maintenance door is provided on the side wall of the lower box structure.

[0011] The beneficial technical effect of the present invention is: the present invention abandons the traditional technical route of independent control according to time sequence, and forms a model of mechanical and electronic integration by adopting the method of mechanical synchronous movement, and multi-factor synchronous control. In many cases, the control strategy with mechanical factors as the main body is the simplest and most reliable. A horizontally movable displacement frame with good rigidity is set on the frame guide rail, and a galvanometer system is set on its upper layer, and a powder supply, powder spreading system and dust exhaust system are designed on the lower layer. The displacement frame is accurately displaced according to the designed step length, and within one step length, the four core steps of SLM technology, namely powder supply, powder spreading, scanning and dust exhaust, are completed simultaneously and coordinately. The displacement frame has precise stopping accuracy (0.005mm), ultra-high reliability and anti-interference ability, and its structure is simple, easy to adjust and repair, and convenient to take out. Its step length can be set and adjusted according to the scanning length of the forming chamber. Large equipment has a large number of steps; small equipment has a small number of steps, which can adapt to the forming of products of various specifications and sizes, especially ultra-large workpieces. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic diagram of the forming principle of the existing SLM equipment;

[0013] Figure 2 It is the main view of the structural principle of the present invention;

[0014] Figure 3 It is a schematic diagram of the powder supply state of the present invention shifting from left to right;

[0015] Figure 4 This is a schematic diagram of the powder supply state of the present invention shifting from right to left;

[0016] Figure 5 This is a schematic diagram of the first step scanning position when performing one layer molding in the present invention;

[0017] Figure 6 This is a schematic diagram of the second step scanning position when performing one layer molding in the present invention;

[0018] Figure 7 This is a schematic diagram of the third step scanning position when performing one layer molding in the present invention;

[0019] Figure 8 This is a schematic diagram of the fourth step scanning position when forming a layer of the present invention. DETAILED DESCRIPTION

[0020] Embodiment: A mechanical synchronous displacement system for super-large SLM equipment comprises a frame 1, a forming cylinder 2, a displacement frame 3, a galvanometer system 4 and a translation drive system, wherein a powder scraping plane 5 is fixedly provided on the frame 1, a forming opening is provided on the powder scraping plane 5, a forming cylinder 2 is mounted on the frame 1, an upper end opening of the forming cylinder 2 can be sealed and connected with the forming opening on the powder scraping plane 5, a piston 6 in the forming cylinder 2 can be moved downward in a dynamic and sealed manner, the displacement frame 3 can be installed on the frame 1 in a horizontal and transverse manner, the translation drive system drives the displacement frame 3 to intermittently move horizontally, the lower end of the displacement frame 3 is in dynamic and sealed contact with the powder scraping plane 5, and the lower end opening of the displacement frame 3 is in a dynamic and sealed manner. The mouth is opposite to the upper opening of the forming cylinder 2. A scraper 7 and a powder supply mechanism 8 are fixedly provided on at least one side wall of the displacement frame 3 along its translation direction. The powder supply mechanism 8 can provide forming powder to the inner side of the forming cylinder 2, and the scraper 7 can scrape the powder in the forming cylinder 2 flat. An air inlet 9 and an air suction port 10 are respectively provided on the two opposite side walls at the lower end of the displacement frame 3. The air inlet 9 can deliver inert gas into the interior of the displacement frame 3, and the air suction port 10 can discharge the gas inside the displacement frame 3. The galvanometer system 4 is fixedly installed on the upper end of the displacement frame 3. The galvanometer system 4 can emit laser towards the powder in the forming cylinder 2 opposite to the lower opening of the displacement frame 3 for melting processing.

[0021] When performing laser melting processing, the displacement frame 3 intermittently moves horizontally from left to right on the powder scraping plane 5, and then intermittently moves horizontally from right to left. As the displacement frame 3 moves horizontally, the powder supply mechanism 8 located on the side wall of the displacement frame 3 supplies powder to the forming cylinder 2. After the powder enters the powder pile area in the forming cylinder 2, the scraper 7 moves with the displacement frame 3 to scrape it flat, and at the same time, the powder on the powder scraping plane 5 is scraped off. After the displacement frame 3 intermittently moves a distance within a step length, the galvanometer system 4 at the upper end of the displacement frame 3 performs laser melting forming on the powder in the forming cylinder 2 facing the displacement frame 3. In this way, as the displacement frame 3 reciprocates, intermittent laser scanning is performed layer by layer in the forming cylinder 2. During surface processing and laser scanning processing, the air inlet 9 and the air intake 10 at the lower end of the displacement frame 3 are aligned with each other, and an inert gas flow is formed inside the lower end of the displacement frame 3, thereby forming sufficient inert gas protection to avoid oxidation during the laser melting process and realize effective dust removal. Moreover, since the powder supply mechanism 8 and the scraper 7 are integrally fixed on the displacement frame 3, powder supply and powder spreading are realized synchronously during the movement of the displacement frame 3, and there is no need to drive the powder supply and powder spreading separately. The present invention ensures the synchronous displacement of the four systems of powder supply, powder spreading, scanning and dust removal, and abandons the traditional scheme of ensuring synchronization through timing control. The present invention has the advantages of simple structure, reliable control, strong anti-interference and low cost.

[0022] The translation drive system includes a servo motor, a reducer and a screw-nut mechanism, wherein the servo motor and the reducer are fixedly mounted on a frame 1, a screw 11 of the screw-nut mechanism is axially stopped and rotatable in a circumferential direction on the frame 1, a nut 12 of the screw-nut mechanism is fixedly connected to a displacement frame 3, and the servo motor drives the screw 11 of the screw-nut mechanism to rotate via the reducer.

[0023] The horizontal transverse movement of the displacement frame 3 is achieved by driving the screw 11 of the screw-nut mechanism to rotate through a servo motor. The horizontal transverse movement of the displacement frame 3 can be intermittently controlled by intermittently controlling the rotation of the screw 11. The movement direction of the displacement frame 3 is controlled by controlling the rotation direction of the screw 11. The above-mentioned driving system can ensure the precise displacement of the displacement frame 3 during horizontal movement. In addition to using this mechanism to drive the horizontal transverse movement of the displacement frame 3, the horizontal transverse movement of the displacement frame 3 can also be driven by a servo motor to drive the gear rack mechanism. This is an equivalent replacement structure that can be easily thought of by technical personnel in this field based on this patent and falls within the scope of protection of this patent.

[0024] The frame 1 is also provided with a horizontally extending linear guide rail 13, and the displacement frame 3 is provided with a slider, which can be slidably mounted on the linear guide rail 13. The displacement frame 3 is accurately guided by the guide system formed by the linear guide rail 13 and the slider, so the parking accuracy can be guaranteed.

[0025] The two opposite side walls of the displacement frame 3 along the translation direction thereof are fixedly provided with a scraper 7 and a powder supply mechanism 8. When the displacement frame 3 translates to the right, the powder supply mechanism 8 and the scraper 7 located on the right side of the displacement frame 3 perform powder spreading; when the displacement frame 3 translates to the left in the return stroke, the powder supply mechanism 8 and the scraper 7 located on the left side of the displacement frame 3 perform powder spreading, forming a two-way powder spreading with high efficiency. The displacement frame 3 moves left and right to form a reciprocating process without an empty stroke, which is conducive to efficient processing and forming.

[0026] The translation distance of the displacement frame 3 each time is smaller than the size of the lower opening of the displacement frame 3 along its translation direction. The displacement frame 3 moves in the frame translation direction with a set step length. Since the step length of each translation of the displacement frame 3 is smaller than the size of the lower opening of the displacement frame 3, the displacement frame 3 has two overlapping displacements. This makes the boundaries of two adjacent laser scans overlap to avoid missing processing areas. This "frame-step length" mechanical rigid displacement mode is easy to set, the step length is easy to adjust, and the overlapping boundary processing ensures the forming accuracy of the workpiece.

[0027] The displacement frame 3 is a barrel-shaped structure with a light-transmitting upper end and an open lower end, and the lower end of the displacement frame 3 is in dynamic sealing contact with the powder scraping plane 5 through a sealing structure. The displacement frame 3 and the powder scraping plane 5 are sealed by the sealing structure, so that the forming chamber is protected by an inert gas during the laser melting forming process, and no oxygen enters to oxidize the workpiece.

[0028] The powder scraping plane 5 is fixedly installed in the frame 1, and the powder scraping plane 5 divides the frame 1 into an upper box structure 14 and a lower box structure 15. The displacement frame 3 and the galvanometer system 4, the powder supply system and the scraper 7 thereon are located in the upper box structure 14, and the forming cylinder 2 is located in the lower box structure 15. The displacement frame 3 can be moved to a position completely misaligned with the forming cylinder 2. A removal door is provided on the side wall of the upper box structure 14, and a maintenance door is provided on the side wall of the lower box structure 15. The upper box body protects the displacement frame 3 and the galvanometer system 4, powder supply system and scraper 7 thereon, and prevents the powder provided by the powder supply mechanism 8 from scattering. The lower box body structure 15 protects the forming cylinder 2. After the workpiece is completely formed, the displacement frame 3 moves to one side and is in a completely misaligned state with the forming cylinder 2. The piston 6 of the forming cylinder 2 rises, and the workpiece is just in the upper box body. The workpiece can be taken out through the picking door, so that the workpiece can be taken out in situ, which is convenient. If there is a problem with the forming cylinder 2 and maintenance is required, it is only necessary to open the maintenance door of the lower box body structure 15 to enter the frame 1 to repair the forming cylinder 2, which is convenient for maintenance.

Claims

1. A mechanical synchronous displacement system for ultra-large SLM equipment, characterized in that: The invention comprises a frame (1), a forming cylinder (2), a displacement frame (3), a galvanometer system (4) and a translation drive system. A powder scraping plane (5) is fixedly provided on the frame. A forming opening is provided on the powder scraping plane. The forming cylinder is mounted on the frame. The upper opening of the forming cylinder can be sealed and connected with the forming opening on the powder scraping plane. The piston (6) in the forming cylinder can be moved downward in a dynamic and sealed manner. The displacement frame can be installed on the frame in a horizontal and transverse manner. The translation drive system drives the displacement frame to intermittently move horizontally. The displacement frame is a barrel-shaped structure with a light-transmitting upper end and an open lower end. The lower end of the displacement frame is in dynamic and sealed contact with the powder scraping plane through a sealing structure. The lower end opening of the displacement frame is directly opposite to the upper end opening of the forming cylinder. A scraper is fixedly provided on at least one side wall of the displacement frame along its translation direction. (7) and a powder supply mechanism (8), the powder supply mechanism can provide forming powder to the inner side of the forming cylinder, the scraper can scrape the powder in the forming cylinder flat, the powder supply mechanism and the scraper are fixed on the displacement frame as a whole, and the powder supply and powder spreading are realized synchronously during the movement of the displacement frame, and there is no need to drive the powder supply and powder spreading separately. An air inlet (9) and an air suction port (10) are respectively provided on the two opposite side walls at the lower end of the displacement frame, the air inlet can deliver inert gas into the interior of the displacement frame, and the air suction port can discharge the gas inside the displacement frame. The galvanometer system is fixedly installed on the upper end of the displacement frame, and the galvanometer system can emit laser toward the powder in the forming cylinder facing the opening at the lower end of the displacement frame for melting processing, thereby ensuring the synchronous displacement of the four systems of powder supply, powder spreading, scanning and dust removal.

2. The mechanical synchronous displacement system for ultra-large SLM equipment according to claim 1, characterized in that: The translation drive system comprises a servo motor, a reducer and a screw nut mechanism, wherein the servo motor and the reducer are fixedly mounted on a frame, a screw (11) of the screw nut mechanism is axially fixed and rotatable in a circumferential direction, and a nut (12) of the screw nut mechanism is fixedly connected to a displacement frame, and the servo motor drives the screw of the screw nut mechanism to rotate via the reducer.

3. The mechanical synchronous displacement system for ultra-large SLM equipment according to claim 1 or 2, characterized in that: The frame is also provided with a horizontally extending linear guide rail (13), and the displacement frame is provided with a sliding block, which can be slidably sleeved on the linear guide rail.

4. The mechanical synchronous displacement system for ultra-large SLM equipment according to claim 2, characterized in that: The two opposite side walls of the displacement frame along the translation direction thereof are both fixedly provided with scrapers and powder supply mechanisms.

5. The mechanical synchronous displacement system for ultra-large SLM equipment according to claim 1, characterized in that: The translation distance of the displacement frame each time is smaller than the size of the opening at the lower end of the displacement frame along its translation direction.

6. The mechanical synchronous displacement system for ultra-large SLM equipment according to claim 1, characterized in that: The powder scraping plane is fixedly installed in the frame, and the powder scraping plane divides the frame into an upper box structure (14) and a lower box structure (15). The displacement frame and the galvanometer system, powder supply system and scraper thereon are located in the upper box structure, and the forming cylinder is located in the lower box structure. The displacement frame can be moved to a position completely dislocated from the forming cylinder. A removal door is provided on the side wall of the upper box structure, and a maintenance door is provided on the side wall of the lower box structure.

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