Movable forming chamber arrangement

Abstract

The utility model discloses a movable forming chamber device, a box body of the forming chamber device is driven by a box body driving device to translate on a scanning field plane, a closed forming space is formed by the box body and the scanning field plane, and a powder feeding system and a powder spreading system are arranged on the outer side wall of the box body and used for synchronously spreading powder along with the movement of the box body. The optical system fixed above the box body emits laser towards the powder field located in the forming space to achieve powder laser melting forming, the air inlet system and the air outlet system arranged on the two sides of the box body enable inert gas to enter and be discharged out of the forming space, an air field is formed in the forming space, and the air field discharges smoke generated by laser melting machining. With the adoption of the laser melting device, the pollution of smoke dust and splashing generated during powder melting to the powder field is effectively reduced, and the cost of an expensive laser optical system is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of laser melting SLM, in particular to a movable forming chamber device. Background Technique

[0002] The laser melting SLM technology is the most important and widely applied forming technology, which is widely used in the forming fields of aerospace engines, 3C manufacturing, and biomedical devices. Its concept is to first form a powder bed, and the laser selectively focuses on its surface layer, melting the powder along the path of the layer file to form a two-dimensional structure (laminar structure), and layer by layer stacking to form a three-dimensional structure. Therefore, for 40 years, the powder beds of all SLM processes have been fixed. In order to increase the forming efficiency and expand the size of the formed parts, the engineering development has taken the technical route of increasing the number of galvanometers (laser beams) on the fixed powder bed, and this technology has achieved certain results. However, with the increase in the laser beam density and laser power, a large amount of dust splash and soot also increase significantly during the laser scanning process, greatly increasing the probability of powder bed contamination, and the optimization effect of the large-scale and extra-large-scale smoke exhaust air field system is not as expected; at the same time, the cost, working stability, and debugging difficulty of the laser optical system have all increased significantly. Content of the Utility Model

[0003] In order to overcome the above defects, the utility model provides a movable forming chamber device. The movable forming chamber device adopts a movable rather than fixed and local rather than overall powder field, and forms the powder bed of SLM with its moving combination, effectively solving the problem of large-scale powder bed contamination.

[0004] The technical solution adopted by the utility model to solve its technical problems: A movable forming chamber device includes a box body, a box body driving device, an optical system, an air inlet system, an air outlet system, a powder feeding system, a powder spreading system, and a control system. The box body driving device can drive the box body to slide along the scanning field plane, and a movable forming space is jointly formed between the box body and the scanning field plane. The powder feeding system and the powder spreading system are fixedly installed on at least one side wall of the box body along its translation direction. The powder feeding system can quantitatively feed powder to the scanning field, and the powder spreading system can spread the powder sent to the scanning field by the powder feeding system to form a powder field. The optical system fixedly installed at the upper end of the box body can emit laser towards the powder field located in the forming space, thereby realizing laser melting forming of the powder in the forming space. The air inlet system and the air outlet system are respectively fixedly installed on two opposite side walls inside the box body, and an air field can be formed between the air inlet system and the air outlet system. The air field can discharge the soot generated by laser melting processing to a designated position. The control system controls the operation of the optical system, the air inlet system, the air outlet system, the powder feeding system, and the box body driving device.

[0005] As a further improvement of the present utility model, the lower end of the box body is in dynamic sealing contact with the scanning field plane, so as to form a sealed forming space between the box body and the scanning field plane. An inert gas supply device and a suction device are also provided. The inert gas supply device is communicated with the air inlet of the air inlet system through an air inlet pipe formed by a telescopic pipe or a flexible pipe, and then the inert gas is sent into the forming space by the air inlet system. The suction device is communicated with the air outlet of the air outlet system through an air outlet pipe formed by a telescopic pipe or a flexible pipe, and then the inert gas and dust in the forming space are sucked out together.

[0006] As a further improvement of the present utility model, the air inlet system includes at least one air inlet chamber, and each air inlet chamber is fixedly installed on one side wall of the box body along its translation direction. Two or more air inlet chambers are arranged at intervals along the up and down direction of the box body. The air inlet chamber is a long strip-shaped cavity structure extending horizontally along the direction perpendicular to the translation direction of the box body, and a number of air outlet holes are evenly spaced on the air inlet chamber; the air outlet system includes at least one exhaust chamber, and the exhaust chamber is fixedly installed on the other side wall of the box body along its translation direction. Two or more exhaust chambers are arranged at intervals along the up and down direction of the box body. The exhaust chamber is a long strip-shaped cavity structure extending horizontally along the direction perpendicular to the translation direction of the box body, and a number of air inlet holes are evenly spaced on the exhaust chamber; each exhaust chamber of the air outlet system is horizontally and oppositely arranged with each air inlet chamber of the air inlet system.

[0007] As a further improvement of the present utility model, the powder feeding system includes a powder hopper, and the powder spreading system includes a scraper. The powder hopper and the scraper are respectively fixedly installed on the outer side wall of the lower end of the box body. A powder pollination cavity with an open lower end is formed in the powder hopper, and the powder pollination cavity can quantitatively hold powder. The powder in the powder pollination cavity can be sprinkled on the scanning field through the opening at the lower end of the powder pollination cavity. The lower end of the scraper is closely attached to the scanning field plane, and the lower end of the scraper is between the opening at the lower end of the powder pollination cavity and the outer side wall of the box body. The scraper can spread the powder sprinkled on the scanning field through the opening at the lower end of the powder pollination cavity into a powder field as the box body translates.

[0008] As a further improvement of the present utility model, the box body driving device is a horizontal precision driving system composed of a servo motor and a lead screw nut mechanism. At least two guide rods extending linearly along the translation direction of the box body are also fixedly installed above the scanning field. The guide rods are parallel to the scanning field plane. At least two guide sleeves are fixedly installed on the box body, and the guide sleeves can be sleeved outside the guide rods in a linear sliding manner.

[0009] As a further improvement of the present utility model, the horizontal precision driving system of the movable forming chamber device and the guiding system formed by the guide rods and the guide sleeves together form a horizontal precision driving and guiding system. The unevenness between the guiding plane formed by the horizontal precision driving and guiding system and the scanning field plane is ≤5μm. During the translation of the movable forming chamber device, the change amount of the distance between its guiding plane and the scanning field plane is ≤2μm.

[0010] As a further improvement of the present utility model, at least one powder feeding system is provided inside the SLM device. The powder feeding system is fixedly installed at one or both ends of the SLM device along the moving direction of the movable forming chamber device. When the movable forming chamber device moves to the extreme position at one end or the other end inside the SLM device, one layer of the powder field in the entire scanning field is scanned. The control system controls the powder feeding system inside the SLM device to quantitatively add powder to the powder hopper of the movable forming chamber device.

[0011] As a further improvement of the present utility model, the top surface of the box body is made of a transparent material, and an optical system mounting base plate is further provided. The optical system mounting base plate is located at the upper end of the box body. At least three adjusting bolts extending in the vertical direction are fixedly provided at the upper end of the box body. At least three mounting holes are provided on the optical system mounting base plate. The three mounting holes on the optical system base plate are respectively sleeved on the adjusting bolts. A positioning nut is further provided. Two positioning nuts are movably threadedly connected to each adjusting bolt. The optical system mounting base plate is tightly clamped between the two positioning nuts. The optical system includes a galvanometer module and an optical fiber. The galvanometer module is fixedly installed on the optical system mounting base plate. The galvanometer of the galvanometer module emits a laser beam into the powder field in the forming space through the transparent top surface of the box body. The optical fiber provides a laser light source for each galvanometer of the galvanometer module.

[0012] As a further improvement of the present utility model, multiple groups of galvanometer modules are provided on the optical system mounting base plate. Each group of galvanometer modules respectively corresponds to different sub-powder fields at different positions in the powder field in the forming space. Each group of galvanometer modules emits a laser beam to the corresponding sub-powder field for laser melting forming.

[0013] As a further improvement of the present utility model, the movable forming chamber device is installed on a robotic arm, a robot, a gantry milling machine, and a radial drill machine. The box body driving device of the movable forming chamber device is the electromechanical system of the robotic arm, the robot, the gantry milling machine, and the radial drill machine.

[0014] The beneficial effects of the present utility model are as follows: The present utility model adopts a movable forming chamber device, abandons the fixed forming chamber, forms a local powder field during its movement, and abandons the fixed powder field; scans this local powder field instead of the entire powder field, thereby completing the melting of the powder for forming; the present utility model greatly shortens the air distance of the air inlet and outlet of the air field, greatly reduces the cost of the air field, optimizes the air field, and effectively reduces the pollution of the powder field by the smoke and dust and splashes generated during the melting of the powder; in addition, the number of laser beams required for scanning the local powder field is greatly reduced, further reducing the smoke and dust, splashes, and the cost of the expensive laser optical system. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a three-dimensional view of the first structure of the movable forming chamber device of the present utility model;

[0016] Figure 2 This is the front view of the first structure of the movable forming chamber device of the present utility model;

[0017] Figure 3 It is Figure 2 a sectional view taken along the A-A direction;

[0018] Figure 4 It is Figure 3 the enlarged view of part B in

[0019] Figure 5 This is the left view of the first structure of the movable forming chamber device of the utility model;

[0020] Figure 6 This is the internal wind field diagram of the movable forming chamber device of the first structure of the utility model;

[0021] Figure 7 This is the perspective view of the second structure of the movable forming chamber device of the present utility model;

[0022] Figure 8 This is the front view of the second structure of the movable forming chamber device of the present utility model;

[0023] Figure 9 It is Figure 8 a sectional view taken along the C-C direction in

[0024] Figure 10 This is the left view of the second structure of the movable forming chamber device of the utility model;

[0025] Figure 11 This is the internal wind field diagram of the movable forming chamber device of the second structure of the utility model;

[0026] Figure 12 This is the schematic diagram of the scanning field partition principle of the present utility model. Specific embodiments

[0027] Embodiment: A movable forming chamber device, comprising a box body 1, a box body driving device, an optical system, an air inlet system, an air outlet system, a powder feeding system, a powder spreading system, and a control system. The box body driving device can drive the box body 1 to slide along the scanning field plane. A movable forming space is jointly formed between the box body 1 and the scanning field plane. The powder feeding system and the powder spreading system are fixedly installed on at least one side wall of the box body 1 along its translation direction. The powder feeding system can quantitatively feed powder to the scanning field 2. The powder spreading system can spread the powder 3 sent by the powder feeding system onto the scanning field 2 to form a powder field 4. The optical system fixedly installed at the upper end of the box body 1 can emit a laser 5 towards the powder field 4 located in the forming space, thereby realizing laser melting forming of the powder 3 in the forming space. The air inlet system and the air outlet system are respectively fixedly installed on two opposite side walls inside the box body 1. An air field 23 can be formed between the air inlet system and the air outlet system. The air field 23 can discharge the soot generated by laser 5 melting processing to a designated position. The control system controls the operation of the optical system, the air inlet system, the air outlet system, the powder feeding system, and the box body driving device.

[0028] While the box body 1 moves on the scanning field 2, the powder spreading system scrapes and spreads the powder 3 sent by the powder feeding system onto the scanning field 2. The powder spreading system only spreads one powder field 4 corresponding to the size of the box body 1 each time. After the box body 1 moves a certain distance, it remains in a stopped state. The box body 1 is just sealed directly above the powder field 4. At this time, the optical system, the air inlet system, and the air outlet system start to work to perform laser melting forming on the powder 3 in this powder field 4, completing a part of the structure in the product slice. Then, the box body 1 moves forward a certain distance again, and the powder spreading system spreads powder synchronously to form the next powder field 4. The optical system, the air inlet system, and the air outlet system are started again for laser 5 melting processing to complete another part of the structure in the product slice until all the structures in one layer of the product slice are completed. The movable forming chamber device can divide the large scanning field 2 into multiple powder fields 4 and perform light scanning on one powder field 4 each time. Since the size of the box body 1 of the movable forming chamber device is small, the size of each powder field 4 is also relatively small. The distance between the air inlet of the air inlet system and the air outlet of the air outlet system in the forming space is relatively close, realizing the optimization of the air field 23 in the forming space, improving the ability of the air field 23 to discharge soot in the forming space, reducing the probability of powder 3 being contaminated, and preventing the soot generated during the laser melting forming process from floating onto the unspread powder 3, avoiding the contamination of the powder 3 to be scanned later during the early scanning in the same layer, avoiding damage to the scraper 11 of the powder spreading system, and ensuring the powder spreading accuracy and the product forming accuracy.

[0029] The lower end of the box body 1 is in dynamic sealing contact with the scanning field plane, so that a sealed forming space is formed between the box body 1 and the scanning field plane. An inert gas supply device and a suction device are also provided. The inert gas supply device is communicated with the air inlet of the air inlet system through an air inlet pipe 21 formed by a telescopic pipe or a flexible pipe, and then the inert gas is sent into the forming space by the air inlet system. The suction device is communicated with the air outlet of the air outlet system through an air outlet pipe 22 formed by a telescopic pipe or a flexible pipe, and then the inert gas and dust in the forming space are sucked out together. Since a sealed forming space is formed between the box body 1 and the scanning field plane, and the air inlet system continuously sends inert gas into the forming space, such as nitrogen and argon, etc., and then, the air outlet system sucks away and discharges the gas mixed with dust by the suction device, so that the oxygen content in the forming space is kept below the design requirement. Therefore, it can ensure that the powder 3 will not be oxidized during the laser melting forming process, and ensure the product quality and accuracy.

[0030] The air inlet system includes at least one air inlet chamber 6. Each air inlet chamber 6 is fixedly installed on one side wall of the box body 1 along its translation direction. Two or more air inlet chambers 6 are arranged at intervals along the up and down direction of the box body 1. The air inlet chamber 6 is a long strip-shaped cavity structure extending horizontally along the direction perpendicular to the translation direction of the box body 1. A number of air outlet holes 7 are evenly spaced on the air inlet chamber 6; the air outlet system includes at least one exhaust chamber 8. The exhaust chamber 8 is fixedly installed on the other side wall of the box body 1 along its translation direction. Two or more exhaust chambers 8 are arranged at intervals along the up and down direction of the box body 1. The exhaust chamber 8 is a long strip-shaped cavity structure extending horizontally along the direction perpendicular to the translation direction of the box body 1. A number of air inlet holes 9 are evenly spaced on the exhaust chamber 8; each exhaust chamber 8 of the air outlet system is arranged horizontally opposite to each air inlet chamber 6 of the air inlet system.

[0031] A number of air outlet holes 7 on the air inlet chamber 6 form the air inlet of the air inlet system, and a number of air inlet holes 9 on the exhaust chamber 8 form the air outlet of the air outlet system.

[0032] Preferably, there is an air inlet chamber 6 on the inner side wall at the lowermost end of the box body 1, and an air inlet chamber 6 on the inner side wall at the upper end of the box body 1. Correspondingly, there is an air exhaust chamber 8 on the inner side wall at the lowermost end of the box body 1, and an air exhaust chamber 8 on the inner side wall at the upper end of the box body 1. The air inlet chamber 6 on the inner side wall at the lowermost end of the box body 1 is opposite to the air exhaust chamber 8. The air field 23 formed between their air inlets and air outlets can discharge a large amount of dust and soot generated during the laser melting forming process of the powder 3 on the scanning field 2 out of the forming space. The air inlet chamber 6 on the inner side wall at the upper end of the box body 1 is opposite to the air exhaust chamber 8. The air field 23 formed between their air inlets and air outlets can discharge the dust and soot entering above the forming space, preventing a small amount of floating dust and soot from adhering to the box body 1. On the one hand, it can avoid the blockage of the laser 5 emitted by the galvanometer module 19 by the dust and soot. On the other hand, it also avoids the damage of the light-transmitting glass at the upper end of the box body 1 caused by the melting of the dust adhered to the light-transmitting glass above the box body 1 when the laser 5 scans the dust.

[0033] The powder feeding system includes a powder hopper 10, and the powder spreading system includes a doctor blade 11. The powder hopper 10 and the doctor blade 11 are respectively fixedly installed on the outer side wall at the lower end of the box body 1. A pollination chamber 12 with an opening at the lower end is formed in the powder hopper 10. The powder 3 can be quantitatively placed in the pollination chamber 12. The powder 3 in the pollination chamber 12 can be sprinkled on the scanning field 2 through the opening at the lower end of the pollination chamber 12. The lower end of the doctor blade 11 is closely attached to the scanning field plane. The lower end of the doctor blade 11 is between the opening at the lower end of the pollination chamber 12 and the outer side wall of the box body 1. As the box body 1 moves horizontally, the doctor blade 11 can spread the powder 3 sprinkled on the scanning field 2 through the opening at the lower end of the pollination chamber 12 to form a powder field 4.

[0034] The pollination chamber 12 in the powder hopper 10 is preferably a funnel-shaped structure with a larger upper size than the lower size. The powder hopper 10 can horizontally extend a certain distance along the direction perpendicular to the moving direction of the box body 1 to form a strip-shaped structure. The powder 3 is scattered through the pollination chamber 12 to form a strip-shaped powder pile. The doctor blade 11 is also a strip-shaped structure that horizontally extends along the direction perpendicular to the moving direction of the box body 1. Its length is preferably greater than the length of the powder hopper 10 to facilitate sufficient powder scraping. The upper end of the doctor blade 11 is preferably a hard structure with a larger size for fixing and positioning on the side wall of the box body 1. The lower end of the doctor blade 11 preferably forms a flat elastic scraping blade with a gradually decreasing size, which can ensure close attachment to the scanning field 2 while not affecting the movement of the box body 1, so as to achieve sufficient leveling of the powder 3.

[0035] The box driving device is a horizontal precision driving and guiding system 13 composed of a servo motor and a lead screw nut mechanism. Above the scanning field 2, at least two guiding rods 14 extending linearly along the translation direction of the box body 1 are fixedly installed. The guiding rods 14 are parallel to the scanning field plane. At least two guiding sleeves 15 are fixedly installed on the box body 1. The guiding sleeves 15 can be sleeved outside the guiding rods 14 in a linear sliding manner. The guiding sleeves 15 can pass through the internal space of the box body 1. Both ends of the guiding sleeves 15 form a sealed fixed connection structure with the side wall of the box body 1, which saves space. In addition, the guiding sleeves 15 can also be fixed outside the box body 1. Preferably, there are two guiding rods 14 and two guiding sleeves 15. The two guiding rods 14 are located on the same guiding plane 24. The guiding plane where the guiding rods 14 are located is parallel to the scanning field 2, which is used to ensure that the box body 1 is always parallel to and in sealed contact with the scanning field 2 during the translation process, ensuring the scanning accuracy.

[0036] The top surface of the box body 1 is made of a transparent material, and an optical system mounting base plate 16 is also provided. The optical system mounting base plate 16 is located at the upper end of the box body 1. At least three adjusting bolts 17 extending in the vertical direction are fixedly installed at the upper end of the box body 1. At least three mounting holes are provided on the optical system mounting base plate 16. The three mounting holes on the optical system base plate are sleeved on the adjusting bolts 17 in one-to-one correspondence. A positioning nut 18 is also provided. Two positioning nuts 18 are movably thread-connected to each adjusting bolt 17. The optical system mounting base plate 16 is tightly clamped between the two positioning nuts 18. The optical system includes a galvanometer module 19 and an optical fiber 20. The galvanometer module 19 is fixedly installed on the optical system mounting base plate 16. The galvanometer of the galvanometer module 19 emits laser beams 5 into the powder field 4 in the forming space through the transparent top surface of the box body 1. The optical fiber 20 provides laser 5 light sources for the galvanometers of the galvanometer module 19. The optical system is installed outside the top of the box body 1 through the optical system mounting base plate 16. By adjusting the positions of the positioning nuts 18 on each adjusting bolt 17, the parallelism and distance between the optical system mounting base plate 16 and the powder field 4 can be adjusted, thereby ensuring that the focus of the laser beams 5 is located on the powder field 4, which is beneficial to improving the processing accuracy.

[0037] A laser melting forming method based on a moving powder field includes the following steps:

[0038] Step 1: Install the movable forming chamber device above one end of the scanning field 2. The lower end of the box body 1 of the movable forming chamber device is in sealed contact with the scanning field plane, so that a forming space is formed between the box body 1 of the movable forming chamber device and the scanning field plane. The inert gas supply device sends inert gas into the forming space through the air inlet system and keeps the inert gas pressure in the forming space greater than one atmosphere (to prevent oxygen from entering);

[0039] Step 2: The control system controls the powder feeding system to quantitatively sprinkle powder at one end of the scanning field plane;

[0040] Step 3: The control system controls the box body driving device and the optical system of the movable forming chamber device to start synchronously and continuously or alternately and intermittently, so that the box body 1 of the movable forming chamber device continuously or intermittently translates in the direction of the other end of the scanning field plane in a dynamic seal manner. While the movable forming chamber device is translating, the powder spreading system thereon starts to continuously or intermittently spread the powder 3 scattered by the powder feeding system at one end of the scanning field plane to form a powder field 4. The optical system continuously or intermittently emits laser 5 beams into the powder field 4 located in the forming space, so as to continuously or intermittently perform laser 5 scanning forming on the powder 3 in the powder field 4. During the laser 5 scanning forming process, the air inlet system continuously feeds inert gas into the forming space formed between the box body 1 and the scanning field plane. The inert gas forms an air field 23 above the powder field 4 and is discharged by the air outlet system. The soot generated during the laser 5 scanning forming process is discharged by the air outlet system together with the inert gas.

[0041] The movable forming chamber device can translate intermittently on the scanning field 2 and stop after translating a certain distance. During the translation process of the movable forming chamber device, the optical system is in a closed state. The powder spreading system synchronously performs intermittent powder spreading on the scanning field plane along with the movement of the movable forming chamber device, so as to sequentially form a plurality of powder fields 4 on the scanning field 2. After the movable forming chamber device stops translating a certain distance, the control system controls the optical system to start. The optical system emits laser 5 beams into the powder field 4 in the forming space to perform laser 5 scanning forming on the formed powder 3. The air inlet system continuously feeds inert gas into the forming space formed between the box body 1 and the scanning field plane. The inert gas forms an air field 23 above the powder field 4 and is discharged by the air outlet system. The soot generated during the laser 5 scanning forming process is discharged by the air outlet system together with the inert gas. After the laser 5 scanning forming of the powder 3 in a powder field 4 by the movable forming chamber device is completed, the control system controls the optical system to stop working and controls the box body driving device to start again, so that the movable forming chamber device translates forward by a set distance again. The powder spreading system spreads powder while the box body 1 is translating to form the next powder field 4 in the next partition of the scanning field 2. The control system controls the box body driving device to stop again and controls the optical system to start again to perform laser 5 scanning forming on the powder 3 in the next powder field 4. This cycle continues until all the powder fields 4 divided on the scanning field 2 are scanned. The forming method of the above-mentioned movable forming chamber device is an intermittent scanning forming method. In addition, the box body driving device and the optical system of the movable forming chamber device can start and stop synchronously, that is, the movable forming chamber device moves, spreads powder, and scans simultaneously. By continuously moving, continuously spreading powder, and continuously scanning on the scanning field 2, the continuous powder field 4 formed on the scanning field 2 is finally scanned completely. During the actual scanning forming process, intermittent scanning forming or continuous scanning forming can be selected according to conditions such as the size and forming accuracy of the product.

[0042] When the movable forming chamber device performs intermittent scanning forming in an intermittent movement manner, before the movable forming chamber device performs translational scanning, the scanning field 2 is first divided along the translational direction of the movable forming chamber device, thereby forming a plurality of partitions. The movable forming chamber device is directly opposite to one partition of the scanning field 2 each time, and the powder spreading system on the movable forming chamber device spreads powder in one partition each time to form a powder field 4. By dividing the scanning field 2 in advance to form a plurality of partitions that match the size of the box body 1 of the movable forming chamber device, the box body 1 of the movable forming chamber device moves from one partition to another partition each time, and the powder spreading system spreads powder in one partition each time, thereby sequentially forming a plurality of powder fields 4 on the scanning field 2. This method is beneficial for the movable forming chamber device to uniformly perform moving laser 5 scanning on the powder 3 in the scanning field 2, which is beneficial for ensuring the processing accuracy and processing efficiency.

[0043] The powder field 4 in the forming space formed between the movable forming chamber device and the scanning field plane is divided to form a plurality of sub-powder fields 25, and the galvanometer modules 19 on the movable forming chamber device are grouped. Each group of galvanometer modules 19 corresponds to one sub-powder field 25, and each group of galvanometer modules 19 emits laser 5 beams to the corresponding sub-powder field 25 for laser melting forming.

[0044] Each group of galvanometer modules 19 may include one or more galvanometer modules 19, and each galvanometer module 19 can emit multiple laser 5 beams to its corresponding sub-powder field 25. For example:

[0045] The size of the scanning field 2 is: 1500mm×1500mm, and its area is: 2.25m 2 ; The scanning field 2 is divided, and the size of each powder field 4 after division is: 300mm×1500mm, and its area is: 0.45m 2 ; Each powder field 4 is partitioned, and the size of each sub-powder field 25 after partitioning is: 300mm×300mm, and its area is: 0.09m 2 , that is, the scanning field 2 has a total of 25 partitions; the galvanometer modules 19 of the optical system of the movable forming chamber device are divided into 5 groups, with two galvanometer modules 19 in each group. Each galvanometer module 19 emits 2 laser 5 beams of 500w. When laser 5 melting processing is performed, each group of galvanometer modules 19 emits laser 5 beams to one sub-powder field 25 for processing. The 5 groups of galvanometer modules 19 respectively emit laser 5 to the 5 sub-powder fields 25 of one powder field 4 to realize synchronous processing of the 5 sub-powder fields 25, with high processing efficiency. Then, after the movable forming chamber device moves to the next powder field 4, the 5 groups of galvanometer modules 19 also emit laser 5 to the 5 sub-powder fields 25 for synchronous processing until all 5 powder fields 4 are processed.

[0046] In addition, it can also be a movable forming chamber device that only covers one sub-powder field 25 each time it moves. The optical system on the movable forming chamber device only emits laser 5 to process this sub-powder field 25. The movable forming chamber device can translate in two mutually perpendicular directions on the scanning field plane, and its moving path forms a zigzag path. That is, after the translation scan completes one row of sub-powder fields 25, the movable forming chamber device moves a certain distance in the vertical direction on the scanning field plane and moves in the opposite direction to scan the next row of sub-powder fields 25. Finally, the scanning of 25 sub-powder fields is completed. The processing efficiency of this method is lower than the previous method, but the box size is small and the galvanometer modules are few.

[0047] The movable forming chamber device is installed above the forming cylinder of the SLM device. The box driving device of the movable forming chamber device is a horizontal precision driving and guiding system 13 composed of a servo motor and a screw-nut mechanism. After all the powder fields 4 divided on the scanning field 2 are scanned, the forming cylinder piston of the SLM device descends by one scanning layer height. The control system controls the movable forming chamber device to move intermittently in the reverse direction and scans each powder field 4 formed in this layer one by one in the reverse direction. This cycle continues until the product is completely scanned and formed.

[0048] The movable forming chamber device is installed on a robotic arm, a robot, a gantry milling machine, and a radial drill. The box driving device of the movable forming chamber device is the electromechanical system of the robotic arm, the robot, the gantry milling machine, and the radial drill.

[0049] At least one powder supply system is provided in the SLM device. The powder supply system is fixedly installed at one or both ends of the SLM device along the moving direction of the movable forming chamber device. When the movable forming chamber device moves to the extreme position at one or both ends of the SLM device, after scanning one layer of all the powder fields 4 on the scanning field 2, the control system controls the powder supply system in the SLM device to quantitatively add powder to the powder hopper 10 of the movable forming chamber device.

[0050] Trigger devices can be respectively arranged at one or both ends in the SLM device. When the movable forming chamber device moves to the extreme position at one or both ends of the SLM device, the powder hopper 10 on the movable forming chamber device is just opposite and communicated with the powder outlet of the powder supply system in the SLM device. At the same time, the powder hopper 10 triggers a trigger device in the SLM device, and the corresponding powder supply system supplies powder 3 to the powder hopper 10. The powder 3 is evenly sprinkled on the scanning field 2 by the powder hopper 10. In this structure, the volume of the powder hopper 10 does not need to be very large, which is beneficial to the lightweight design of the movable forming chamber device. In addition, a powder storage space can be formed in the powder hopper 10, and a quantitative powder discharging structure can be formed in the powder hopper 10 to quantitatively supply powder 3 to the powder application cavity 12 by itself. This structure does not depend on the powder supply system in the SLM device and can supply powder and feed powder separately, but it has a large volume and a large weight.

[0051] The horizontal precision drive system of the movable forming chamber device and the guiding system formed by the guiding rods and guiding sleeves together form a horizontal precision drive and guiding system. The flatness of the guiding plane formed by the horizontal precision drive and guiding system and the scanning field plane is ≤ 5 μm. During the translation of the movable forming chamber device, the variation in the distance between its guiding plane and the scanning field plane is ≤ 2 μm.

[0052] To achieve a movable powder field, this patent designs a movable forming chamber device (a large-scale one is called a movable forming chamber, and a smaller one is called a movable forming head). The so-called movable forming chamber (head) refers to a closed space box structure, the oxygen content inside which should be less than or equal to the required value. Its top is equipped with a galvanometer optical system, its side walls are equipped with air supply and air suction systems, and its bottom is equipped with a powder feeding system and a powder spreading system. The characteristics of this patent are that the laser optical system, the air supply and air suction systems, the powder feeding system, and the powder spreading system are fixed relative to the forming chamber (head), and a powder field can be formed during the movement of the forming chamber (head), the air field removes dust and smoke, and the laser beam performs scanning. This greatly reduces the size of the traditional powder bed and the probability of powder contamination; it also greatly reduces the distance between the inlet and outlet, creating a prerequisite for optimizing the air field.

[0053] This patent uses the method of a movable powder field to break through the method of the SLS powder bed (Powder Bed) that originated in 1985: first constructing a complete powder bed and then performing full-field scanning or ordered local scanning of the powder bed for forming.

[0054] The method of this patent avoids the most fatal problems in the SLM process: the powder bed is contaminated by dust and smoke, in the same layer, the prior scanning contaminates the subsequent scanning, and even forms build-ups, scrapes and overturns the formed part, and damages the blade.

Claims

1. A movable forming chamber device, characterized in that: It includes a box body (1), a box body driving device, an optical system, an air inlet system, an air outlet system, a powder feeding system, a powder spreading system and a control system. The box body driving device can drive the box body to slide along the plane of the scanning field (2), and a movable forming space is jointly formed between the box body and the scanning field plane. The powder feeding system and the powder spreading system are fixedly installed on at least one side wall of the box body along its translation direction. The powder feeding system can quantitatively feed powder to the scanning field, and the powder spreading system can spread the powder (3) sent to the scanning field by the powder feeding system to form a powder field (4). The optical system fixedly installed at the upper end of the box body can emit laser (5) towards the powder field located in the forming space, thereby realizing laser melting forming of the powder in the forming space. The air inlet system and the air outlet system are respectively fixedly installed on two opposite side walls inside the box body, and an air field (23) can be formed between the air inlet system and the air outlet system. The air field can discharge the soot generated by laser melting processing to a designated position. The control system controls the operation of the optical system, the air inlet system, the air outlet system, the powder feeding system and the box body driving device.

2. The movable forming chamber device according to claim 1, characterized in that: The lower end of the box body is in dynamic sealing contact with the scanning field plane, so that a sealed forming space is formed between the box body and the scanning field plane. An inert gas supply device and a suction device are also provided. The inert gas supply device is communicated with the air inlet of the air inlet system through an air inlet pipe (21) formed by a telescopic pipe or a flexible pipe, and then the inert gas is sent into the forming space by the air inlet system. The suction device is communicated with the air outlet of the air outlet system through an air outlet pipe (22) formed by a telescopic pipe or a flexible pipe, and then the inert gas and soot in the forming space are sucked out together.

3. The movable forming chamber device according to claim 1, characterized in that: The air inlet system includes at least one air inlet chamber (6). Each air inlet chamber is fixedly installed on one side wall of the box body along its translation direction. Two or more air inlet chambers are arranged at intervals in the up and down direction of the box body. The air inlet chamber is a long strip-shaped cavity structure extending horizontally along the direction perpendicular to the translation direction of the box body. A number of air outlet holes (7) are evenly spaced on the air inlet chamber; the air outlet system includes at least one exhaust chamber (8). The exhaust chamber is fixedly installed on the other side wall of the box body along its translation direction. Two or more exhaust chambers are arranged at intervals in the up and down direction of the box body. The exhaust chamber is a long strip-shaped cavity structure extending horizontally along the direction perpendicular to the translation direction of the box body. A number of air inlet holes (9) are evenly spaced on the exhaust chamber; each exhaust chamber of the air outlet system is horizontally opposite to each air inlet chamber of the air inlet system.

4. The movable forming chamber device according to claim 1, characterized in that: The powder feeding system includes a powder hopper (10), and the powder spreading system includes a scraper (11). The powder hopper and the scraper are respectively fixedly installed on the outer side wall of the lower end of the box body. A pollination cavity (12) with an opening at the lower end is formed in the powder hopper. The pollination cavity can quantitatively hold powder, and the powder in the pollination cavity can be sprinkled on the scanning field through the opening at the lower end of the pollination cavity. The lower end of the scraper is in close contact with the scanning field plane. The lower end of the scraper is between the opening at the lower end of the pollination cavity and the outer side wall of the box body. As the box body moves, the scraper can spread the powder sprinkled on the scanning field through the opening at the lower end of the pollination cavity to form a powder field.

5. The movable forming chamber device according to claim 1, characterized in that: The box driving device is a horizontal precision driving system (13) composed of a servo motor and a lead screw nut mechanism. At least two guide rods (14) extending linearly along the translation direction of the box are fixedly installed above the scanning field. The guide rods are parallel to the scanning field plane. At least two guide sleeves (15) are fixedly installed on the box, and the guide sleeves can be sleeved outside the guide rods in a linear sliding manner.

6. The movable forming chamber device according to claim 5, characterized in that: The horizontal precision driving system of the movable forming chamber device and the guiding system formed by the guide rods and the guide sleeves together form a horizontal precision driving and guiding system. The unevenness between the guiding plane formed by the horizontal precision driving and guiding system and the scanning field plane is ≤5 μm. During the translation process of the movable forming chamber device, the variation in the distance between its guiding plane and the scanning field plane is ≤2 μm.

7. The movable forming chamber device according to claim 4, characterized in that: At least one powder supply system is provided in the SLM device. The powder supply system is fixedly installed at one or both ends of the SLM device along the movement direction of the movable forming chamber device. When the movable forming chamber device moves to the extreme position at one or the other end of the SLM device, one layer of scanning of all powder fields in the scanning field is completed, and the control system controls the powder supply system in the SLM device to quantitatively add powder to the powder hopper of the movable forming chamber device.

8. The movable forming chamber device according to claim 1, characterized in that: The top surface of the box is made of a transparent material, and an optical system mounting base plate (16) is also provided. The optical system mounting base plate is located at the upper end of the box. At least three adjusting bolts (17) extending in the vertical direction are fixedly provided at the upper end of the box. At least three mounting holes are provided on the optical system mounting base plate. The three mounting holes on the optical system base plate are sleeved on the adjusting bolts one by one. A positioning nut (18) is also provided. Two positioning nuts are movably threadedly connected to each adjusting bolt, and the optical system mounting base plate is tightly clamped between the two positioning nuts. The optical system includes a galvanometer module (19) and an optical fiber (20). The galvanometer module is fixedly installed on the optical system mounting base plate, and the galvanometer of the galvanometer module emits a laser beam into the powder field in the forming space through the transparent top surface of the box. The optical fiber provides a laser light source for each galvanometer of the galvanometer module.

9. The movable forming chamber device according to claim 8, wherein: Multiple groups of galvanometer modules are provided on the optical system mounting base plate. Each group of galvanometer modules corresponds one by one to the individual powder fields at different positions in the powder field in the forming space, and each group of galvanometer modules emits a laser beam to the corresponding sub-powder field for laser melting forming.

10. The movable forming chamber device according to claim 1, characterized in that: The movable forming chamber device is installed on a robotic arm, a robot, a gantry milling machine, and a radial drill. The box driving device of the movable forming chamber device is the electromechanical system of the robotic arm, the robot, the gantry milling machine, and the radial drill.

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