Scratchless powder spreading device for additive manufacturing

Abstract

The application belongs to the technical field of additive manufacturing equipment, and particularly relates to a powder spreading device without scraper for additive manufacturing, which comprises a forming bottom plate, a powder spreading platform, a powder falling unit and a driving unit. The powder spreading platform is arranged on the forming bottom plate and is in sliding connection with the forming bottom plate. The powder falling unit is located above the powder spreading platform. The driving unit is arranged on the forming bottom plate and is connected with the powder spreading platform. The driving unit drives the powder spreading platform to cyclically slide back and forth in the horizontal direction of the forming bottom plate. The powder falling unit completes powder spreading on the powder spreading platform once per cycle. The powder spreading device without scraper for additive manufacturing is provided, powder spreading without scraper is realized, the occurrence of scraper sticking and powder sticking is avoided, and the forming quality and forming efficiency of additive manufacturing are improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of additive manufacturing equipment, and particularly relates to a powder spreading device without scraper for additive manufacturing. BACKGROUND

[0002] The additive manufacturing technology is a way of layer-by-layer manufacturing based on three-dimensional CAD model data by adding materials. In the layer-by-layer manufacturing process, the powder is often spread to a certain thickness. The existing technology usually adopts a contact type powder spreading device such as a scraper or a powder spreading roller to spread the powder.

[0003] Taking the scraper as an example, although the layer-by-layer powder spreading can be realized, the contact type powder spreading device has the following shortcomings:

[0004] (1) During the powder spreading process, the scraper is easy to be stuck due to the local protrusion of the formed part. The stuck scraper often causes the vibration of the equipment, affects the optical precision, and affects the reliability and service life of the equipment. The stuck scraper also causes the inconsistent powder thickness, affects the forming precision and quality, and is easy to scratch and damage the part, resulting in forming failure and part scrap. If the stuck scraper is serious, the forming process will be interrupted. In this case, the forming chamber door needs to be opened to destroy the high-temperature and inert gas protection atmosphere, and the repair treatment is carried out by manual grinding, which not only affects the forming efficiency but also affects the forming quality.

[0005] (2) During the powder spreading process, the scraper and the scraper holder are often in contact with the powder, and the powder is easy to stick to the contact parts. After the powder sticks, when the scraper moves to the forming area again, the powder attached to the scraper may fall into the formed area, and the powder falling place will form a powder protrusion accumulation, which affects the forming precision and quality and is more likely to cause the scraper to be stuck. Therefore, a new powder spreading device needs to be proposed to solve the above problems. SUMMARY

[0006] In view of the technical problems of the stuck scraper and the powder sticking of the existing scraper powder spreading device, the present application provides a powder spreading device without scraper for additive manufacturing, which realizes the powder spreading without scraper, avoids the occurrence of the stuck scraper and the powder sticking of the scraper, and improves the forming quality and efficiency of the additive manufacturing.

[0007] In order to achieve the above purpose, the technical scheme adopted by the present application is as follows:

[0008] A powder spreading device without scraper for additive manufacturing comprises a forming bottom plate, a powder spreading platform, a powder falling unit and a driving unit. The powder spreading platform is arranged on the forming bottom plate and is in sliding connection with the forming bottom plate. The powder falling unit is located above the powder spreading platform. The driving unit is arranged on the forming bottom plate and is connected with the powder spreading platform. The driving unit drives the powder spreading platform to slide back and forth in the horizontal direction of the forming bottom plate. The powder falling unit completes powder spreading once for each cycle of sliding of the powder spreading platform.

[0009] Further, the powder spreading device for additive manufacturing without scraper further comprises sliding members arranged between the powder spreading platform and the forming base plate, the sliding members comprising linear guides and sliding blocks; the linear guides are arranged on the forming base plate, and the axial direction of the linear guides is the same as the horizontal direction of the forming base plate; the sliding blocks are sleeved on the linear guides and connected with the powder spreading platform; there are two sliding members, and the two sliding members are arranged at the two ends of the powder spreading platform in the longitudinal direction of the forming base plate.

[0010] Further, the driving unit comprises a roller shaft and a roller which are coaxially sleeved from inside to outside, the roller is arranged on the forming base plate, the axial direction of the roller is the same as the longitudinal direction of the forming base plate, and the roller is connected with the forming base plate; one end of the powder spreading platform is wound on the roller, and the roller shaft drives the powder spreading platform to cyclically slide back and forth in the horizontal direction of the forming base plate.

[0011] Further, the driving unit further comprises a spring connected with the other end of the powder spreading platform; the axial direction of the spring is the same as the horizontal direction of the forming base plate, and the spring is connected with the forming base plate.

[0012] Further, there are two springs, and the two springs are arranged at the two ends of the powder spreading platform in the longitudinal direction of the forming base plate.

[0013] Further, the driving unit comprises a magnetic coupling rodless cylinder and a cylinder sliding block; the magnetic coupling rodless cylinder is arranged on the forming base plate, the cylinder sliding block is sleeved on the magnetic coupling rodless cylinder and connected with the powder spreading platform; the magnetic coupling rodless cylinder drives the cylinder sliding block to drive the powder spreading platform to cyclically slide back and forth in the horizontal direction of the forming base plate.

[0014] Further, the powder spreading device for additive manufacturing without scraper further comprises buffer limiting members located in the peripheral direction of the powder spreading platform, the buffer limiting members comprising spring buffers and buffer mounting seats, and the spring buffers are connected with the forming base plate through the buffer mounting seats.

[0015] Further, there are multiple buffer limiting members, and the multiple buffer limiting members are arranged on the two sides of the powder spreading platform in the longitudinal direction of the forming base plate in reverse symmetry.

[0016] Further, the driving unit comprises driving unit A, driving unit B and driving unit C which are arranged on the forming base plate from left to right in sequence and have the same structure, driving unit A and driving unit B are connected with the forming base plate, driving unit C is connected with the sliding block of the sliding member, one end of the powder spreading platform is wound on the roller of driving unit A, the other end of the powder spreading platform is wound on the roller of driving unit B after passing through the roller of driving unit C, and the roller shaft drives the powder spreading platform to cyclically slide back and forth in the horizontal direction of the forming base plate.

[0017] Further, the powder falling unit comprises a powder storage cabin and a powder falling device which are sequentially communicated from top to bottom, and the powder falling device is located above the powder spreading platform; the height distance between the powder falling device and the powder spreading platform is 0.1mm-10mm.

[0018] The present application has the following advantages:

[0019] 1. The powder spreading platform is driven by the driving unit to move back and forth in the horizontal direction of the forming base plate, and the powder falling unit completes powder spreading on the powder spreading platform once per cycle, and the powder spreading process is non-contact, so that the powder spreading without scraper is realized, the scraper sticking and the scraper sticking are avoided, and the additive manufacturing forming quality and forming efficiency are improved.

[0020] 2. The driving unit has two modes, one of which is realized by a roller, and the other of which is realized by a cylinder, and the two driving modes are simple to operate, easy to realize and practical and flexible.

[0021] 3. The driving unit comprises a roller shaft and a roller which are coaxially sleeved from inside to outside, and the driving unit further comprises a spring connected to the other end of the powder spreading platform, and the spring cooperates with the roller to realize rapid powder spreading and improve powder spreading efficiency.

[0022] 4. The driving unit comprises a magnetic coupling rodless cylinder and a cylinder sliding block; and further comprises a buffer limiting piece located in the peripheral direction of the powder spreading platform, the buffer limiting piece comprises a spring buffer and a buffer mounting seat, and the spring buffer can buffer and limit the powder spreading platform when the powder spreading platform moves back and forth in a cycle, so as to prevent the powder spreading platform from sliding out of the forming base plate and separating from the linear guide rail, and ensure the stability and safety of the device. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 The present application is a schematic diagram of the additive manufacturing device without scraper powder spreading of embodiment 1 Figure 1 ;

[0024] Figure 2 The present application is a schematic diagram of the additive manufacturing device without scraper powder spreading of embodiment 1 Figure 2 ;

[0025] Figure 3 The present application is a schematic diagram of the additive manufacturing device without scraper powder spreading of embodiment 1 Figure 3 ;

[0026] Figure 4 The present application is a schematic diagram of the additive manufacturing device without scraper powder spreading of embodiment 1 powder from the powder falling device to the powder spreading platform;

[0027] Figure 5 The present application is a schematic diagram of the additive manufacturing device without scraper powder spreading of embodiment 1 powder from the powder spreading platform to the powder bed;

[0028] Figure 6 Schematic diagram of the powder spreading device without scraper for additive manufacturing of the present application embodiment 2 Figure 1 ;

[0029] Figure 7 Schematic diagram of the powder spreading device without scraper for additive manufacturing of the present application embodiment 2 Figure 2 ;

[0030] Figure 8 Schematic diagram of the powder spreading device without scraper for additive manufacturing of the present application embodiment 2 Figure 3 ;

[0031] Figure 9 Schematic diagram of the powder spreading device without scraper for additive manufacturing of the present application embodiment 2 Figure 4 ;

[0032] Figure 10 Schematic diagram of the powder spreading device without scraper for additive manufacturing of the present application embodiment 2 powder moving from the powder falling device to the powder spreading platform;

[0033] Figure 11 Schematic diagram of the powder spreading device without scraper for additive manufacturing of the present application embodiment 2 powder moving from the powder spreading platform to the powder bed;

[0034] Figure 12 Schematic diagram of the powder spreading device without scraper for additive manufacturing of the present application embodiment 3 powder moving from the powder falling device to the powder spreading platform;

[0035] In the figure:

[0036] 1 - powder storage cabin, 2 - powder falling device, 3 - forming bottom plate, 4 - forming platform, 5 - spring, 6 - spring fixing seat, 7 - forming cylinder, 8 - protective cover, 9 - linear guide rail, 10 - sliding block, 11 - powder spreading platform, 12 - roller support, 13 - roller shaft, 14 - roller, 15 - spring buffer, 16 - buffer mounting seat, 17 - sliding block II, 18 - magnetic coupling rodless air cylinder, 19 - cylinder sliding block. DETAILED DESCRIPTION

[0037] The technical solutions provided by the present application will be illustrated in detail below in combination with the drawings and examples.

[0038] The embodiments of the present application will be described in detail below in combination with examples, so that the realization process of how the present application applies technical means to solve technical problems and achieve technical effects can be fully understood and implemented.

[0039] Example 1

[0040] Referring to Figures 1-3The no-blade powder spreading device for additive manufacturing provided by the embodiment comprises a forming base plate 3, a powder spreading platform 11, a powder falling unit and a driving unit; the powder spreading platform 11 is arranged on the forming base plate 3 and is in sliding connection with the forming base plate 3, the powder falling unit is located above the powder spreading platform 11; the driving unit is arranged on the forming base plate 3 and is connected with the powder spreading platform 11, the driving unit drives the powder spreading platform 11 to cyclically slide back and forth in the horizontal direction of the forming base plate 3, and the powder falling unit completes powder spreading on the powder spreading platform 11 once for each cycle of sliding.

[0041] The powder falling unit comprises a powder storage cabin 1 and a powder falling device 2 which are sequentially connected from top to bottom, and the powder falling device 2 is located above the powder spreading platform 11. Specifically, the powder falling device 2 is installed at the lower part of the powder storage cabin 1 and is fixedly connected with the powder storage cabin 1 as a whole, and the height distance between the lower surface of the powder falling device 2 and the upper surface of the powder spreading platform 11 is 8 mm.

[0042] The powder storage cabin 1 is located above the powder falling device 2 and serves to store powder; the powder falling device 2 is located above the powder spreading platform 11 and serves to uniformly drop the powder in the powder storage cabin 1 onto the powder spreading platform 11 for powder spreading.

[0043] The no-blade powder spreading device for additive manufacturing further comprises a sliding member arranged between the powder spreading platform 11 and the forming base plate 3, the sliding member comprises a linear guide rail 9 and a sliding block 10; the linear guide rail 9 is arranged on the forming base plate 3, and the axial direction of the linear guide rail 9 is the same as the horizontal direction of the forming base plate 3, and the sliding block 10 is sleeved on the linear guide rail 9 and is connected with the powder spreading platform 11. There are two sliding members, and the two sliding members are arranged at the two ends of the powder spreading platform 11 in the longitudinal direction of the forming base plate 3.

[0044] The driving unit comprises a roller shaft 13 and a roller 14 which are coaxially sleeved from inside to outside, the roller 14 is arranged on the forming base plate 3, the axial direction of the roller 14 is the same as the longitudinal direction of the forming base plate 3, and the driving unit is connected with the forming base plate 3 through a roller support 12; one end of the powder spreading platform 11 is wound on the roller 14, and the roller shaft 13 drives the powder spreading platform 11 to cyclically slide back and forth in the horizontal direction of the forming base plate 3.

[0045] The driving unit further comprises a spring 5 connected with the other end of the powder spreading platform 11; the axial direction of the spring 5 is the same as the horizontal direction of the forming base plate 3, and the spring 5 is connected with the forming base plate 3. There are two springs 5, and the two springs 5 are arranged at the two ends of the powder spreading platform 11 in the longitudinal direction of the forming base plate 3.

[0046] Referring to Figure 1 The forming base plate 3 is a rectangular plate, a slot is arranged at the right end of the forming base plate 3, a forming cylinder 7 is arranged at the lower part of the slot, and the forming platform 4 moves in the height direction inside the forming cylinder 7 during the forming process.

[0047] When setting up, the left and right directions of the forming base plate 3 are defined as the horizontal direction, the longitudinal direction as the front and back direction, and the vertical direction as the height direction. Then, the powder dropper 2 is located in the vertical direction of the forming base plate 3, and the distance between it and the upper surface of the powder spreading platform 11 is 8mm.

[0048] The powder spreading platform 11 has the same shape as the forming base plate 3, but the size of the powder spreading platform 11 is smaller than that of the forming base plate 3. The powder spreading platform 11 is placed on the forming base plate 3 and has the same placement direction as the forming base plate 3. The powder spreading platform 11 is slidably connected to the forming base plate 3 through a sliding member.

[0049] Springs 5 ​​are respectively installed at the right end of the forming base plate 3. One end of each spring 5 is fixed to a spring fixing seat 6, which is installed on the forming base plate 3. The other end of each spring 5 is connected to the right end of the powder spreading platform 11. One spring 5 and one spring fixing seat 6 are installed at the front and one at the rear of the right end of the forming base plate 3.

[0050] Two linear guide rails 9 are arranged in parallel along the longitudinal direction of the forming base plate 3, one at the front and one at the rear of the forming base plate 3. The two linear guide rails 9 are arranged on the front and rear sides of the slot. Both linear guide rails 9 are mounted on the forming base plate 3 with screws. The sliders 10 are located on the linear guide rails 9. The powder spreading platform 11 and the sliders 10 are fixed together with screws. The powder spreading platform 11 is fixed to the sliders 10 at the front and rear positions on the right side. Protective covers 8 are set between the two linear guide rails 9 and the slot of the forming base plate 3. The number of protective covers 8 is the same as that of the linear guide rails 9, with one arranged in the front and rear directions of the slot. They are mounted on the forming base plate 3 with screws. The installation of protective covers 8 on the forming base plate 3 can reduce powder dust.

[0051] The right side of the powder spreading platform 11 is fixed to two sliders 10, and the left side of the powder spreading platform 11 is wound around the roller 14. The roller 14 and the roller shaft 13 are fixed together as a whole. There is a roller support 12 at each end of the roller shaft. The power source (including but not limited to the motor) acts on the roller shaft 13 through the transmission device (including but not limited to the reducer, coupling, transmission shaft, etc.), which can drive the roller 14 to rotate. Under the combined action of the rotational motion of the roller 14 and the spring 5, the powder spreading platform 11 can move back and forth in the left and right directions. The movement stroke of the powder spreading platform 11 can cover the entire forming area.

[0052] See Figures 2-4 In this embodiment, during the powder spreading process, the powder spreading platform 11 starts at the left side of the forming base plate 3, exposing the entire forming area. The roller shaft 13 rotates counterclockwise, and the powder spreading platform 11 slides to the right along the horizontal direction of the forming base plate 3 under the combined action of the roller 14 and the spring 5. Simultaneously, the powder dropper 2, according to process requirements and the speed of the powder spreading platform 11, drops powder onto the powder spreading platform 11 (e.g., ...). Figure 4As shown), after the powdering platform 11 moves to the designated position on the right side, the powdering platform 11 can cover the entire forming area (as shown Figure 3 Subsequently, the roller shaft 13 rotates clockwise, and the powdering platform 11 moves quickly to the left under the joint action of the roller 14 and the spring 5. The powder on the powdering platform 11 is separated from the powdering platform 11, and after losing the support of the powdering platform 11, the powder falls on the powder bed (the uppermost layer of powder in the forming cylinder 7) in turn under the action of gravity (as shown Figure 5 The distance between the powdering platform 11 and the upper surface of the powder bed is 0.1mm-3mm. After the completion of one layer of powdering, the powdering platform 11 continues to move in the same direction to the starting position on the left side, and waits for the next round of reciprocating cycle to complete one layer of powdering.

[0053] After the completion of one layer of powdering, the laser scans the current powder layer to form a part, and after the completion of the current layer, the part and the powder in the forming cylinder 7 are lowered by one layer under the driving of the forming platform 4, and the powdering action is repeated.

[0054] Example 2

[0055] Referring to Figures 6-8 The no-blade powdering device for additive manufacturing provided in the embodiment comprises a forming base plate 3, a powdering platform 11, a powder falling unit and a driving unit. The powdering platform 11 is arranged on the forming base plate 3 and is in sliding connection with the forming base plate 3. The powder falling unit is located above the powdering platform 11. The driving unit is arranged on the forming base plate 3 and is connected with the powdering platform 11. The driving unit drives the powdering platform 11 to slide back and forth in the horizontal direction of the forming base plate 3. The powder falling unit completes one layer of powdering on the powdering platform 11 each time the powdering platform 11 slides back and forth once.

[0056] The no-blade powdering device for additive manufacturing further comprises a sliding member arranged between the powdering platform 11 and the forming base plate 3. The sliding member comprises a linear guide rail 9 and a sliding block 10. The linear guide rail 9 is arranged on the forming base plate 3, and the axial direction of the linear guide rail 9 is the same as the horizontal direction of the forming base plate 3. The sliding block 10 is sleeved on the linear guide rail 9 and is connected with the powdering platform 11. There are two sliding members, which are arranged at the two ends of the powdering platform 11 in the longitudinal direction of the forming base plate 3.

[0057] The powder falling unit comprises a powder storage cabin 1 and a powder falling device 2 arranged in sequence from top to bottom. The powder falling device 2 is located above the powdering platform 11. The height distance between the powder falling device 2 and the powdering platform 11 is 6mm.

[0058] The driving unit includes a magnetic coupling rodless cylinder 18 and a cylinder slider 19. The magnetic coupling rodless cylinder 18 is arranged on the forming base plate 3, and the cylinder slider 19 is sleeved on the magnetic coupling rodless cylinder 18 and connected with the powder laying platform 11. The magnetic coupling rodless cylinder 18 drives the cylinder slider 19 to drive the powder laying platform 11 to move back and forth in the horizontal direction of the forming base plate 3.

[0059] The no-blade powder laying device for additive manufacturing further includes a buffer limiting piece arranged on the outer circumferential direction of the powder laying platform 11. The buffer limiting piece includes a spring buffer 15 and a buffer mounting seat 16. The spring buffer 15 is connected with the forming base plate 3 through the buffer mounting seat 16. There are multiple buffer limiting pieces, which are arranged on the two sides of the powder laying platform 11 in the longitudinal direction of the forming base plate 3 in reverse symmetry.

[0060] In the embodiment, the forming base plate 3 has a slot, and the lower part of the slot is arranged with a forming cylinder 7. During the forming process, the forming platform 4 moves in the height direction inside the forming cylinder 7.

[0061] The powder laying platform 11 has the same shape as the forming base plate 3, but the size of the powder laying platform 11 is smaller than that of the forming base plate 3. The powder laying platform 11 is arranged on the forming base plate 3 and has the same arrangement direction as the forming base plate 3. The powder laying platform 11 is slidably connected with the forming base plate 3 through a sliding piece.

[0062] There is one linear guide rail 9 in the front-rear direction of the forming base plate 3, which is installed on the forming base plate 3 through a screw. The slider 10 and the slider II 17 are located on the linear guide rail 9, that is, there are two sliders on one linear guide rail 9. The slider 10 and the slider II 17 are respectively fixed with the powder laying platform 11 through screws, that is, the front and rear positions of the left and right sides of the powder laying platform 11, that is, the four corners of the powder laying platform are fixed with the two sliders of the linear guide rail 9 through screws. The protective cover 8 is arranged between the linear guide rail 9 and the slot of the forming base plate 3, and the number of the protective cover 8 is the same as that of the linear guide rail 9. There is one protective cover 8 arranged in the front-rear direction, which is installed on the forming base plate 3 through a screw.

[0063] There is one spring buffer 15 arranged at the middle position of the right side of the forming base plate 3. The spring buffer 15 is installed on the buffer mounting seat 16, and the buffer mounting seat 16 is fixed on the forming base plate 3 through a screw. There is also one spring buffer 15 arranged at the front and rear positions of the left side of the forming base plate 3, which is fixed on the forming base plate 3 through the buffer mounting seat 16. There are three spring buffers 15 in total. When the powder laying platform 11 moves to the corresponding positions of the left and right sides, the spring buffers 15 on the left and right sides can buffer and limit the powder laying platform 11.

[0064] Referring to Figure 9, the magnetic coupling rodless cylinder 18 is installed on the left side of the forming base plate 3 by screw, the axial direction of the magnetic coupling rodless cylinder 18 is consistent with the horizontal direction of the forming base plate 3, the cylinder sliding block 19 is the moving part of the magnetic coupling rodless cylinder 18, the cylinder sliding block 19 is placed on the magnetic coupling rodless cylinder 18, the cylinder sliding block 19 is connected with the powder laying platform 11 by screw, under the action of compressed gas, the magnetic coupling rodless cylinder 18 can drive the cylinder sliding block 19 to move along the left and right directions of the magnetic coupling rodless cylinder 18, so as to drive the powder laying platform 11 to move back and forth to realize the cyclic sliding, and the moving stroke of the powder laying platform 11 can cover the whole forming area.

[0065] In the powder laying process of the embodiment, the initial position of the powder laying platform 11 is on the left side of the forming base plate 3, and the whole forming area is exposed, as shown in Figure 7 The cylinder sliding block 19 on the magnetic coupling rodless cylinder 18 drives the powder laying platform 11 to move to the right, and at the same time, the powder falling device falls the powder on the powder laying platform 11 according to the process requirement and the moving speed of the powder laying platform 11, as shown in Figure 6 and Figure 10 When the powder laying platform 11 moves to the right side and covers the whole forming area, the powder laying platform 11 contacts with the spring buffer 15, as shown in Figure 8 Then, the cylinder sliding block 19 on the magnetic coupling rodless cylinder 18 drives the powder laying platform 11 to move to the left quickly, the powder on the powder laying platform 11 is separated from the powder laying platform 11, and after the powder loses the support of the powder laying platform 11, the powder falls on the powder bed (the uppermost layer of the powder in the forming cylinder 7) under the action of gravity, as shown in Figure 11 The interval between the powder laying platform 11 and the upper surface of the powder bed is 0.1mm-3mm. After the powder laying is completed, the powder laying platform 11 continues to move to the left initial position along the same direction, and waits for the next cycle to realize the powder laying again.

[0066] After the powder laying of one layer is completed, the laser scans the formed part of the current powder layer, and after the current layer is formed, the part and the powder in the forming cylinder 7 are lowered by one layer from the forming platform 4, and the powder laying action is repeated.

[0067] Embodiment 3

[0068] Referring to Figure 12 , the embodiment provides a non-blade powder laying device for additive manufacturing, which comprises a forming base plate 3, a powder laying platform 11, a powder falling unit and a driving unit; the powder laying platform 11 is placed on the forming base plate 3 and is in sliding connection with the forming base plate 3, the powder falling unit is located above the powder laying platform 11; the driving unit is placed on the forming base plate 3 and is connected with the powder laying platform 11, the driving unit drives the powder laying platform 11 to cyclically slide back and forth in the horizontal direction of the forming base plate 3, and the powder falling unit completes the powder laying on the powder laying platform 11 once every cycle.

[0069] When setting, the left-right direction of the forming base plate 3 is set as the horizontal direction, the longitudinal direction is set as the front-rear direction, and the vertical direction is set as the height direction. The powder falling device 2 is located in the vertical direction of the forming base plate 3, and the distance between the upper surface of the powder laying platform 11 and the powder falling device 2 is 8 mm.

[0070] In this embodiment, the forming base plate 3 has a slot, and the lower part of the slot is arranged with a forming cylinder 7. During the forming process, the forming platform 4 moves in the height direction inside the forming cylinder 7.

[0071] The powder laying platform 11 has the same shape as the forming base plate 3, but the size of the powder laying platform 11 is smaller than that of the forming base plate 3. The powder laying platform 11 is placed on the forming base plate 3 and has the same placement direction as the forming base plate 3. The powder laying platform 11 is connected to the forming base plate 3 through a sliding member.

[0072] The powder falling unit includes a powder storage cabin 1 and a powder falling device 2 connected in sequence from top to bottom. The powder falling device 2 is located above the powder laying platform 11. Specifically, the powder falling device 2 is installed at the lower part of the powder storage cabin 1 and is fixedly connected to the powder storage cabin 1 as a whole. The height distance between the lower surface of the powder falling device 2 and the upper surface of the powder laying platform 11 is 10 mm.

[0073] The no-blade powder laying device for additive manufacturing further includes a sliding member arranged between the powder laying platform 11 and the forming base plate 3. The sliding member includes a linear guide rail 9 and a sliding block 10. The linear guide rail 9 is arranged on the forming base plate 3, and the axial direction of the linear guide rail 9 is the same as the horizontal direction of the forming base plate 3. The sliding block 10 is sleeved on the linear guide rail 9 and is connected to the powder laying platform 11. There are two sliding members, which are arranged at the two ends of the powder laying platform 11 in the longitudinal direction of the forming base plate 3.

[0074] The driving unit includes a roller shaft 13 and a roller 14 which are coaxially sleeved in sequence from inside to outside. The roller 14 is arranged on the forming base plate 3, and the axial direction of the roller 14 is the same as the longitudinal direction of the forming base plate 3.

[0075] There are three driving units, including a driving unit A, a driving unit B and a driving unit C which are arranged in sequence from left to right on the forming base plate 3. The driving unit A and the driving unit B are connected to the forming base plate 3 through the roller support 12. The driving unit C is connected to the sliding block of the sliding member through the roller support 12. The sliding block drives the driving unit C to slide along the axial direction of the linear guide rail 9. One end of the powder laying platform 11 is wound around the roller 14 of the driving unit A, and the other end is wound around the roller 14 of the driving unit C and then wound around the roller 14 of the driving unit B. The roller shaft 13 drives the powder laying platform 11 to slide back and forth in the horizontal direction of the forming base plate 3.

[0076] In implementation, the powder falling unit is located above the powder spreading platform 11, one end of the powder spreading platform 11 is wound around the roller 14 of the driving unit A, and the other end is wound around the roller 14 of the driving unit B after passing through the roller 14 of the driving unit C. During powder spreading, the roller of the driving unit A rotates clockwise, and at the same time, the driving unit C slides to the right along the linear guide rail 9, driving the powder spreading platform 11 to move from left to right to the slot. During the movement, the powder falling device 2 of the powder falling unit falls powder on the powder spreading platform 11. During powder spreading, the roller of the driving unit A still rotates clockwise, and at the same time, the driving unit C slides to the right along the linear guide rail 9, and then reaches the right edge of the powder spreading area, the powder falling device 2 stops falling powder, and then the driving unit A and the powder spreading unit B rotate clockwise at the same time. At this time, the rotation speed of the roller 14 of the driving unit A is greater than the rotation speed of the powder spreading unit B, and at the same time, the driving unit C slides to the left along the linear guide rail 9. The powder on the powder spreading platform 11 is separated from the powder spreading platform 11. After the powder loses the support of the powder spreading platform 11, it falls on the powder bed (the uppermost layer of powder in the forming cylinder 7) under the action of gravity. The distance between the powder spreading platform 11 and the upper surface of the powder bed is 0.1mm-3mm. After powder spreading is completed, the powder spreading platform 11 continues to move in the same direction to the left starting position, waiting for the next cycle of reciprocating, and again spreading powder.

[0077] After one layer of powder spreading is completed, the laser scans the current powder layer to form a part. After the current layer is formed, the part and the powder in the forming cylinder 7 are lowered by one layer from the forming platform 4, and the powder spreading action is repeated again.

[0078] The above is three specific embodiments of the present application, but the technical solutions protected by the present application are not limited thereto. The non-scraper powder spreading device for additive manufacturing provided by the present application is characterized in that the powder spreading platform reciprocates within the full width range of the powder bed, the powder falls from the powder storage cabin 1 to the powder spreading platform 11 through the powder falling device 2, the powder falling device 2 falls powder while the powder spreading platform 11 moves to the forming area at a certain speed, the powder spreading platform 11 moves quickly in the opposite direction after reaching the desired position, the powder on the powder spreading platform 11 is separated from the powder spreading platform 11, and the powder loses the support of the powder spreading platform 11 and falls on the powder bed under the action of gravity, realizing non-scraper powder spreading.

Claims

1. A doctor blade free powder spreading device for additive manufacturing, characterized in that, The device comprises a forming base plate (3), a powder laying platform (11), a powder falling unit and a driving unit; the powder laying platform (11) is arranged on the forming base plate (3) and is in sliding connection with the forming base plate (3), the powder falling unit is arranged above the powder laying platform (11); the left-right direction of the forming base plate (3) is the horizontal direction, and the longitudinal direction is the front-back direction; the driving unit is arranged on the forming base plate (3) and is connected with the powder laying platform (11), the driving unit drives the powder laying platform (11) to cyclically slide back and forth in the horizontal direction of the forming base plate (3), and the powder falling unit completes powder laying on the powder laying platform (11) once for each cycle of sliding. A slot is arranged on the right end of the forming base plate (3), and a forming cylinder (7) is arranged at the lower part of the slot. The driving unit comprises a roller shaft (13) and a roller (14) which are coaxially sleeved from inside to outside, the roller (14) is arranged on the forming base plate (3), the axial direction of the roller (14) is the same as the longitudinal direction of the forming base plate (3), and the roller shaft (13) is connected with the forming base plate (3); one end of the powder laying platform (11) is wound on the roller (14), and the roller shaft (13) drives the powder laying platform (11) to cyclically slide back and forth in the horizontal direction of the forming base plate (3).

2. The doctorless powder spreading device for additive manufacturing according to claim 1, characterized in that The device further comprises sliding members arranged between the powder laying platform (11) and the forming base plate (3), the sliding members comprise linear guides (9) and sliding blocks (10); the linear guides (9) are arranged on the forming base plate (3), and the axial direction of the linear guides (9) is the same as the horizontal direction of the forming base plate (3), the sliding blocks (10) are sleeved on the linear guides (9) and are connected with the powder laying platform (11); there are two sliding members, and the two sliding members are arranged at the two ends of the powder laying platform (11) in the longitudinal direction of the forming base plate (3); protective covers (8) are arranged between the two linear guides (9) and the slot of the forming base plate (3), and the protective covers (8) are installed on the forming base plate (3) by screws.

3. A doctor blade free powder spreading device for additive manufacturing according to claim 2, characterized in that, The driving unit further comprises springs (5) connected with the other end of the powder laying platform (11); the axial direction of the springs (5) is the same as the horizontal direction of the forming base plate (3), and the springs (5) are connected with the forming base plate (3).

4. The doctorless powder spreading device for additive manufacturing according to claim 3, characterized in that There are two springs (5), and the two springs (5) are arranged at the two ends of the powder laying platform (11) in the longitudinal direction of the forming base plate (3).

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