Grid compensation scanning system

Abstract

The invention discloses a grid compensation scanning system which is characterized in that a frame driving device drives a movable wind field frame to intermittently and horizontally move in the X direction in a forming space of 3D printing equipment, and a plurality of grids which are arranged at intervals in the X direction are formed in the movable wind field frame of a grid structure; a plurality of laser galvanometer systems arranged in the X direction scan powder fields in the ranges of all grids of the movable wind field frame respectively, a plurality of air blowing openings and air suction openings are formed in the two side walls of all the grids respectively, and an air supply header pipe and an air return header pipe on the outer side wall of the movable wind field frame are correspondingly communicated with all the air blowing openings and all the air suction openings respectively. The air supply main pipe is connected with one end of an air supply sliding pipe with the adjustable length, the air return main pipe is connected with one end of an air return sliding pipe with the adjustable length, and the other ends of the air supply sliding pipe and the air return sliding pipe are communicated with an air return opening and an air supply opening of a protective gas circulation system respectively.

Description

Technical Field

[0001] The present invention relates to a 3D printing device, and particularly to a grid compensation scanning system. Background Art

[0002] With the popularization of 3D printing, the workpieces produced are becoming more and more delicate and larger in size. As a result, two major contradictions have emerged. On the one hand, for delicate requirements, the forming space needs to be clean, free of dust and soot. For large-area scanning, multiple lasers need to work simultaneously to shorten the forming time and thus quickly complete 3D forming. However, due to the large area of the wind field of the protective gas, even with jet flow, it cannot meet the requirements, resulting in splashing and smoke, seriously affecting the forming quality of metal 3D parts. When multiple lasers need to work simultaneously for large areas to shorten the forming time and quickly complete 3D forming, it is also impossible to arrange them due to the large volume of the laser galvanometer (about 350X600 (including beam expansion, collimation, etc.), and the scanning area is about 400X400). It can be arranged with three axes, but the control is complex and unstable. With the up-and-down arrangement, the cooperation and manufacturing of the two groups of objective lenses are not guaranteed. Summary of the Invention

[0003] To make up for the above deficiencies, the present invention provides a grid compensation scanning system, which can achieve fast large-area scanning and high forming accuracy.

[0004] The technical solution adopted by the present invention to solve its technical problems is: a grid compensation scanning system, including a laser galvanometer system, a moving wind field frame, a frame driving device, a main air supply pipe, a main air return pipe, an air supply slide pipe, an air return slide pipe, and a protective gas circulation system. Let the X direction and the Y direction be two mutually perpendicular directions on the horizontal plane. The moving wind field frame is horizontally movably installed in the forming space of the 3D printing device along the X direction. The frame driving device drives the moving wind field frame to intermittently move horizontally back and forth. The moving wind field frame is a grid structure, and a number of grids arranged at intervals along the X direction are formed therein. A number of groups of laser galvanometer systems are arranged along the X direction. Each group of laser galvanometer systems can scan the powder field within the range of one grid of the moving wind field frame. A number of air blowing ports are provided on one side wall of each grid of the moving wind field frame, and a number of air suction ports are provided on the other side wall of each grid of the moving wind field frame. The outer side wall of the moving wind field frame is also provided with a main air supply pipe and a main air return pipe. Each air blowing port is respectively communicated with the main air supply pipe, and each air suction port is respectively communicated with the main air return pipe. One end of the main air supply pipe is connected to one end of the air supply slide pipe whose length can be adjusted, and one end of the main air return pipe is connected to one end of the air return slide pipe whose length can be adjusted. The other ends of the air supply slide pipe and the air return slide pipe are respectively communicated with the air return port and the air supply port of the protective gas circulation system.

[0005] As a further improvement of the invention, at least one air supply channel extending in the Y direction is provided inside one side wall of each grid of the mobile air flow field frame, and at least one air return channel extending in the Y direction is provided inside the other side wall of each grid of the mobile air flow field frame. The air outlet is located on the side wall of the air supply channel, and the air suction port is located on the side wall of the air return channel. The air supply channel and the air return channel are respectively communicated with the main air supply pipe and the main air return pipe. The multiple air supply channels and the multiple air return channels are arranged at intervals in the up-and-down direction.

[0006] As a further improvement of the invention, the main air supply pipe and the main air return pipe both extend in the X direction, and the main air supply pipe and the main air return pipe are respectively located on the two side walls of the mobile air flow field frame along the Y direction. The air supply channel and the air return channel are respectively vertically and cross-connected to the side walls of the main air supply pipe and the main air return pipe through pipe joints.

[0007] As a further improvement of the invention, the air supply sliding pipe and the air return sliding pipe are telescopic pipes with an elastically telescopic length.

[0008] As a further improvement of the invention, one end of the air supply sliding pipe and the air return sliding pipe are respectively connected to the main air supply pipe and the main air return pipe in a sealing and pluggable manner that can slide relative to each other.

[0009] As a further improvement of the invention, the internal space of the forming chamber of the 3D printing device forms a forming space. The mobile air flow field frame is installed on the inner side wall of the forming chamber, and the laser galvanometer system is fixedly installed on the top of the forming chamber. The laser emitted by the laser galvanometer system can scan the powder field inside the grid of the mobile air flow field frame.

[0010] As a further improvement of the invention, a mobile box body capable of horizontally moving in the X direction and a box body driving device for driving the mobile box body to intermittently move horizontally are provided inside the forming chamber of the 3D printing device. A mobile forming space is jointly formed between the mobile box body and the powder field plane. The mobile air flow field frame is installed on the inner side wall of the mobile box body, and the laser galvanometer system is fixedly installed at the upper end of the mobile box body. The laser emitted by the laser galvanometer system can scan the powder field inside the grid of the mobile air flow field frame through the transparent top plate of the mobile box body.

[0011] As a further improvement of the invention, precision grating measuring devices are further provided on the two side walls of the mobile box body in the Y direction. The precision grating measuring devices can measure the X displacement of the two side walls of the mobile box body in the Y direction. The precision grating measuring devices can perform closed-loop calculation based on the measurement data and then correct the difference from the scanning zero point of the previous layer, so that the current scanning zero point coincides with the scanning zero point of the previous layer.

[0012] As a further improvement of the invention, a guide rail extending in the X direction is provided on the moving wind field frame. The frame driving device includes a first motor, a first speed reducer, and a first camshaft. The first camshaft is rotatably mounted on the side wall of the forming space along the Y direction in the circumferential direction. A first cam is coaxially and fixedly connected to the outer circumferential side wall of the first camshaft. The rotation of the first cam can drive the guide rail to move in the X direction, and the first motor drives the first camshaft to rotate forward and backward through the first speed reducer.

[0013] As a further improvement of the invention, an adjustment groove extending vertically is further provided on the side wall of the forming space along the Y direction. A second camshaft is slidably inserted into the adjustment groove in the vertical direction. A second cam is coaxially and fixedly connected to the second camshaft. The rotation of the second cam can drive the guide rail to move in the vertical direction. A second motor and a second speed reducer are also provided. The second motor drives the second camshaft to rotate forward and backward through the second speed reducer.

[0014] The beneficial technical effects of the present invention are as follows: The present invention divides the unstable large wind field into several independent and stable narrow wind fields through the moving wind field frame, which can meet the cleanliness of the scanning space during scanning, avoid being affected by dust during scanning, and is conducive to realizing fine scanning. Moreover, the present invention scans the powder fields in each grid within the moving wind field frame simultaneously with multiple lasers. The scanning area is large. After one scan is completed, only need to move the moving wind field frame a very small distance in the X direction to expose the covered position of the moving wind field frame, and then perform another scan to complete the scanning of one layer of the powder field, which is conducive to realizing high-efficiency scanning processing. The present invention also measures the variables after the movement of the moving wind field frame through a precision grating measuring device, corrects the coincidence of the original zero point of the current layer and the zero point of the previous layer, so that the current layer will not cause misalignment with the previous layer, thereby ensuring the quality of the workpiece. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the wind speed curve of the wind field in the forming space;

[0016] Figure 2 It is a schematic diagram of the laser scanning principle of the invention;

[0017] Figure 3 It is a schematic diagram of the structure principle of the moving wind field frame of the invention;

[0018] Figure 4 It is a schematic diagram of the three-dimensional structure principle of the present invention;

[0019] Figure 5 It is the first state diagram of the principle of sequential scanning in columns using a moving box of the present invention;

[0020] Figure 6 It is the second state diagram of the principle of sequential scanning in columns using a moving box of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0021] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0022] Embodiment: A grid compensation scanning system includes a laser galvanometer system 1, a mobile wind farm frame 2, a frame drive device, an air supply main 3, an air return main 4, an air supply slide 5, an air return slide 6 and a protective gas circulation system. Assume that the X direction and the Y direction are two directions perpendicular to each other on the horizontal plane. The mobile wind farm frame 2 can be installed in the forming space 17 of the 3D printing device and can be moved horizontally along the X direction. The frame drive device drives the mobile wind farm frame 2 to move horizontally back and forth intermittently. The mobile wind farm frame 2 is a grid structure, which is formed with a plurality of grids 7 arranged at intervals along the X direction. A plurality of groups of laser galvanometer systems 1 are arranged along the X direction. Each group of laser galvanometer systems 1 can move the mobile wind farm frame 2 horizontally. The powder field within the range of a grid 7 of the field frame 2 is scanned, and a plurality of blowing outlets 8 are provided on one side wall of each grid 7 of the mobile wind field frame 2, and a plurality of suction outlets 9 are provided on the other side wall of each grid 7 of the mobile wind field frame 2. An air supply main pipe 3 and an air return main pipe 4 are also provided on the outer wall of the mobile wind field frame 2, and each blowing outlet 8 is respectively connected to the air supply main pipe 3, and each air suction outlet 9 is respectively connected to the return air main pipe 4. The air supply main pipe 3 is connected to one end of an air supply slide pipe 5 with an adjustable length, and the return air main pipe 4 is connected to one end of a return air slide pipe 6 with an adjustable length. The other ends of the air supply slide pipe 5 and the return air slide pipe 6 are respectively connected to the return air inlet and the air supply inlet of the protective gas circulation system.

[0023] A grid-like mobile wind farm frame 2 is installed within the forming space 17 of the 3D printing device. This frame is equipped with an array of blowing ports 8 and suction ports 9 for ejecting and absorbing shielding gas. The blowing ports 8 are connected to the shielding gas filtration system's supply ports via a main air supply pipe 3 and a supply slide 5. The suction ports 9 are connected to the shielding gas filtration system's return ports via a main air return pipe 4 and a return slide 6. This structure of the mobile wind farm frame 2 divides a large, unstable wind field into several independent, stable, narrow wind fields, enabling the successful completion of large-scale metal 3D printing.

[0024] Multiple columns of laser galvanometer systems 1 can be mounted above the mobile wind farm frame 2, performing simultaneous multi-column scanning, significantly reducing scanning time. After a scan is completed, the mobile wind farm frame 2 can simply be moved once to expose the area obscured by the previous scan. This area can then be scanned again, completing a large-format scan of 2-3 meters wide. Because the frame requires fewer movements and shorter intervals, the impact on workpiece temperature gradients is minimal, improving workpiece forming quality and offering unparalleled advantages for the manufacture of large workpieces.

[0025] In each side wall of each grid 7 of the moving air field frame 2, there is at least one air supply channel extending in the Y direction. In each side wall of the other side of each grid 7 of the moving air field frame 2, there is at least one air return channel extending in the Y direction. The air outlet 8 is located on the side wall of the air supply channel, and the air suction port 9 is located on the side wall of the air return channel. The air supply channel and the air return channel are respectively communicated with the air supply main pipe 3 and the air return main pipe 4. A plurality of air supply channels and a plurality of air return channels are arranged at intervals in the up and down direction. This structure can supply protective gas to all air supply channels through one air supply main pipe 3 and absorb the gas in all air return channels through one air return main pipe 4. The overall structure is simple. The air outlets 8 and the air suction ports 9 are arranged at uniform intervals in the Y direction, and the pressure of the protective gas blown out by all the air outlets 8 is the same, making the air flow in the air field uniform and conducive to ensuring the scanning quality.

[0026] Both the air supply main pipe 3 and the air return main pipe 4 extend in the X direction, and the air supply main pipe 3 and the air return main pipe 4 are respectively located on the two side walls of the moving air field frame 2 along the Y direction. The air supply channel and the air return channel are respectively vertically and cross-connected to the side walls of the air supply main pipe 3 and the air return main pipe 4 through pipe joints 10.

[0027] The air supply sliding pipe 5 and the air return sliding pipe 6 are telescopic pipes with an elastically telescopic length. By designing the air supply sliding pipe 5 and the air return sliding pipe 6 as structures that can elastically expand and contract, when the air supply main pipe 3 and the air return main pipe 4 move with the moving air field frame 2, the air supply sliding pipe 5 and the air return sliding pipe 6 can be pulled to expand and contract for adjustment, ensuring that the protective gas supply pipeline in the 3D printing device will not be damaged and will not interfere with the operation of other mechanisms.

[0028] One ends of the air supply sliding pipe 5 and the air return sliding pipe 6 are respectively hermetically inserted and connected to the air supply main pipe 3 and the air return main pipe 4 in a relatively slidable manner. The air supply sliding pipe 5 and the air return sliding pipe 6 are connected to the air supply main pipe 3 and the air return main pipe 4 by means of dynamic sealing and sliding insertion, enabling them to slide relative to each other to adapt to the position change of the air supply main pipe 3 and the air return main pipe 4 when they move with the moving air field frame 2.

[0029] The internal space of the forming chamber 11 of the 3D printing device forms a forming space 17. The moving air field frame 2 is installed on the inner side wall of the forming chamber 11, and the laser galvanometer system 1 is fixedly installed on the inner top of the forming chamber 11. The laser emitted by the laser galvanometer system 1 can scan the powder field in the grid 7 of the moving air field frame 2. This structure is suitable for the case where the scanning area is not particularly large, and when the laser galvanometer system 1 can be normally arranged on the top surface of the forming chamber 11, the entire forming chamber 11 can be divided into an air field by the moving air field frame 2.

[0030] Inside the forming chamber 11 of the 3D printing device, there is a moving box body 12 that can move horizontally along the X direction and a box body driving device that drives the intermittent horizontal movement of the moving box body 12. A mobile forming space 17 is jointly formed between the moving box body 12 and the powder field plane. The moving air field frame 2 is installed on the inner side wall of the moving box body 12, and the laser galvanometer system 1 is fixedly installed on the upper end of the moving box body 12. The laser emitted by the laser galvanometer system 1 can pass through the transparent top plate of the moving box body 12 to scan the powder field in the grid 7 of the moving air field frame 2. When the total scanning area in the forming chamber 11 is huge and the laser galvanometer system 1 cannot be normally arranged on the top surface of the forming chamber 11, the forming chamber 11 is divided into multiple forming spaces 17 by the moving box body 12, and the laser galvanometer system 1 is installed on the moving box body 12. The laser galvanometer system 1 scans a column of powder field directly opposite to the moving box body 12 each time. After completion, the moving box body 12 moves a distance of one column to the right and starts the scanning of the next column. During scanning, the moving box body 12 remains stationary. This forms a method of splitting columns, sequential displacement, and stationary scanning, which can achieve ultra-large area scanning and can be scanned by a small number of laser galvanometer systems 1. The moving box body 12 can be made as wide as possible, and the moving air field frame 2 is installed inside it. After the moving box body 12 moves to a column position, a scan is first performed, and then the moving air field frame 2 is misaligned and another scan is performed. In this way, on the one hand, the number of movements of the moving box body 12 can be greatly reduced, and the air field inside it can be ensured to be stable. This solution can achieve large-area, high-efficiency, and high-quality scanning.

[0031] On the two side walls of the moving box body 12 in the Y direction, there are also precision grating measuring devices. The precision grating measuring devices can measure the X displacement of the two side walls of the moving box body 12 along the Y direction. The precision grating measuring devices can perform closed-loop calculations based on the measurement data and then correct the difference from the scanning zero point of the previous layer, so that the current scanning zero point coincides with the scanning zero point of the previous layer. Before scanning, the difference from the zero point of the previous layer is corrected by high-precision grating detection to coincide with the zero point of the previous layer to ensure that there is no layer misalignment between the current layer and the previous layer, which is used to ensure the shape, dimensions, etc. of the formed part and ensure that there is no layer misalignment between the current layer and the previous layer, which is used to ensure the shape of the formed part.

[0032] A guide rail 13 extending in the X direction is provided on the moving wind field frame 2. The frame driving device includes a first motor, a first speed reducer, and a first camshaft 14. The first camshaft 14 is rotatably mounted on the side wall of the forming space 17 in the Y direction in the circumferential direction. A first cam is coaxially fixedly connected to the outer circumferential side wall of the first camshaft 14. The rotation of the first cam can drive the guide rail 13 to move in the X direction. The first motor drives the first camshaft 14 to rotate forward and backward through the first speed reducer. By rotating the first camshaft 14, the first cam drives the moving wind field frame 2 to move a certain distance in the X direction to offset the blocked part of the frame, forming a supplement function. This driving structure is simple, occupies little space, has a fast response speed, and accurate position.

[0033] An adjustment slot 15 extending vertically is further provided on the side wall of the forming space in the Y direction. A second camshaft 16 is slidably inserted in the adjustment slot 15 in the up and down direction. A second cam is coaxially fixedly connected to the second camshaft 16. The rotation of the second cam can drive the guide rail 13 to move in the up and down direction. A second motor and a second speed reducer are also provided. The second motor drives the second camshaft 16 to rotate forward and backward through the second speed reducer. By rotating the second camshaft 16, the second cam drives the moving wind field frame 2 to move a certain distance in the up and down direction, realizing the height adjustment function of the moving wind field frame 2, and further adjusting the height of the air blowing port 8 and the air suction port 9, ensuring that all the soot is sucked away during scanning and realizing fine scanning.

Claims

1. A grating compensation scanning system, characterized in that: It includes a laser galvanometer system (1), a movable wind field frame (2), a frame driving device, a main air supply pipe (3), a main air return pipe (4), an air supply sliding pipe (5), an air return sliding pipe (6) and a protective gas circulation system. Let the X direction and the Y direction be two mutually perpendicular directions on the horizontal plane. The movable wind field frame is horizontally movably installed in the forming space (17) of the 3D printing device along the X direction. The frame driving device drives the movable wind field frame to intermittently move horizontally back and forth. The movable wind field frame is a grid structure, and several grids (7) arranged at intervals along the X direction are formed therein. Several groups of laser galvanometer systems are arranged along the X direction. Each group of laser galvanometer systems can scan the powder field within the range of one grid of the movable wind field frame. A plurality of air blowing ports (8) are provided on one side wall of each grid of the movable wind field frame, and a plurality of air suction ports (9) are provided on the other side wall of each grid of the movable wind field frame. The main air supply pipe and the main air return pipe are also provided on the outer side wall of the movable wind field frame. Each air blowing port is respectively communicated with the main air supply pipe, and each air suction port is respectively communicated with the main air return pipe. The main air supply pipe is connected to one end of the air supply sliding pipe with adjustable length, and the main air return pipe is connected to one end of the air return sliding pipe with adjustable length. The other ends of the air supply sliding pipe and the air return sliding pipe are respectively communicated with the air return port and the air supply port of the protective gas circulation system.

2. The grille compensation scanning system according to claim 1, characterized in that: At least one air supply channel extending along the Y direction is provided in one side wall of each grid of the movable wind field frame, and at least one air return channel extending along the Y direction is provided in the other side wall of each grid of the movable wind field frame. The air blowing ports are located on the side walls of the air supply channels, and the air suction ports are located on the side walls of the air return channels. The air supply channels and the air return channels are respectively communicated with the main air supply pipe and the main air return pipe. A plurality of air supply channels and a plurality of air return channels are arranged at intervals in the up and down direction.

3. The grid compensation scanning system according to claim 2, characterized in that: Both the main air supply pipe and the main air return pipe extend along the X direction, and the main air supply pipe and the main air return pipe are respectively located on the two side walls of the movable wind field frame along the Y direction. The air supply channels and the air return channels are respectively connected to the side walls of the main air supply pipe and the main air return pipe perpendicularly and crosswise through pipe joints (10).

4. The grid compensation scanning system according to claim 1, characterized in that: The air supply sliding pipe and the air return sliding pipe are telescopic pipes with elastically telescopic lengths.

5. The grille compensation scanning system according to claim 1, characterized in that: One ends of the air supply sliding pipe and the air return sliding pipe are respectively connected to the main air supply pipe and the main air return pipe in a sealed and pluggable manner that can slide relative to each other.

6. The grille compensation scanning system according to claim 1, characterized in that: The internal space of the forming chamber (11) of the 3D printing device forms a forming space. The movable wind field frame is installed on the inner side wall of the forming chamber, and the laser galvanometer system is fixedly installed on the top inside the forming chamber. The laser emitted by the laser galvanometer system can scan the powder field within the grids of the movable wind field frame.

7. The grille compensation scanning system according to claim 1, characterized in that: A movable box body (12) that can horizontally move along the X direction and a box body driving device that drives the movable box body to intermittently move horizontally are provided inside the forming chamber of the 3D printing device. A movable forming space is jointly formed between the movable box body and the powder field plane. The movable wind field frame is installed on the inner side wall of the movable box body, and the laser galvanometer system is fixedly installed at the upper end of the movable box body. The laser emitted by the laser galvanometer system can scan the powder field within the grids of the movable wind field frame through the transparent top plate of the movable box body.

8. The grille compensation scanning system according to claim 7, characterized in that: The moving box body is further provided with precision grating measuring devices on the side walls on both sides in the Y direction. The precision grating measuring devices can measure the X displacement of the side walls of the moving box body along the Y direction. The precision grating measuring devices can perform closed-loop calculation based on the measurement data and then correct the difference from the scanning zero point of the previous layer, so that the current scanning zero point coincides with the scanning zero point of the previous layer.

9. The grille compensation scanning system according to claim 6 or 7, characterized in that: A guide rail (13) extending in the X direction is provided on the moving wind field frame. The frame driving device includes a first motor, a first speed reducer and a first camshaft (14). The first camshaft is rotatably mounted on the side wall of the forming space along the Y direction in the circumferential direction. A first cam is coaxially and fixedly connected to the outer circumferential side wall of the first camshaft. The rotation of the first cam can drive the guide rail to move in the X direction. The first motor drives the first camshaft to rotate forward and backward through the first speed reducer.

10. The grid compensation scanning system according to claim 9, characterized in that: An adjustment slot (15) extending vertically is further provided on the side wall of the forming space along the Y direction. A second camshaft (16) is slidably inserted in the adjustment slot in the vertical direction. A second cam is coaxially and fixedly connected to the second camshaft. The rotation of the second cam can drive the guide rail to move in the vertical direction. A second motor and a second speed reducer are also provided. The second motor drives the second camshaft to rotate forward and backward through the second speed reducer.

Images