Powder spreading mechanism, additive manufacturing equipment and powder spreading method

Abstract

The invention relates to the technical field of additive manufacturing, aims to solve the technical problem that some known powder spreading mechanisms are difficult to give consideration to simple structure and improvement of powder spreading quality, and provides a powder spreading mechanism, additive manufacturing equipment and a powder spreading method. The powder spreading mechanism comprises a stock bin, a powder feeding roller, a driving part and a powder pressing roller. And the material bin is provided with a powder outlet. And the powder feeding roller is matched with the powder outlet. The driving piece is connected with the powder feeding roller and used for driving the powder feeding roller to rotate. The powder pressing roller is in transmission connection with the powder feeding roller through a transmission assembly and can be driven by the powder feeding roller to rotate. The powder spreading device has the beneficial effects that the simple structural design is considered, and the powder spreading quality of powder materials is guaranteed.

Description

Technical Field

[0001] The present application relates to the field of additive manufacturing technology, and in particular to a powder spreading mechanism, additive manufacturing equipment and a powder spreading method. Background Art

[0002] After the 3D printing device completes the powder dropping action, it needs to use a scraper or roller to flatten and compact the laid powder material. Since the scraper has a poor flattening and compacting effect in some powder laying scenarios, in order to ensure the compaction effect of the roller, the powder feeding roller and compaction roller of the powder laying mechanism of some known 3D printing devices need to be controlled by an independent power source, making the structure of the powder laying mechanism more complicated. Summary of the invention

[0003] The present application provides a powder spreading mechanism and a powder spreading mechanism, an additive manufacturing device and a powder spreading method to solve the technical problem that some known powder spreading mechanisms are difficult to balance between simple structure and improved powder spreading quality.

[0004] The embodiment of the present application is implemented as follows:

[0005] In a first aspect, the present application provides a powder spreading mechanism, comprising a silo, a powder feeding roller, a driving member and a powder pressing roller. The silo is provided with a powder outlet. The powder feeding roller is matched with the powder outlet. The driving member is connected to the powder feeding roller and is used to drive the powder feeding roller to rotate. The powder pressing roller is connected to the powder feeding roller through a transmission assembly and can rotate under the drive of the powder feeding roller.

[0006] When the powder spreading mechanism of the present application is working, the driving member drives the powder feeding roller to rotate, and drives the powder material in the silo to rotate synchronously until it is discharged from the powder outlet, thereby completing the powder dropping action of the powder material. During the rotation of the powder feeding roller, the transmission assembly also drives the powder feeding roller to rotate. After the powder material falls onto the powder spreading surface, the rotating powder feeding roller can flatten the powder material and fluidize the powder material to improve the uniformity of the pressed powder material and the density of the powder material, thereby improving the powder spreading quality of the powder material, which is beneficial to improving the molding quality of the molding layer of additive manufacturing. At the same time, the power sources of the powder feeding roller and the powder pressing roller are all from the same driving member, thereby saving the number of power sources of the powder spreading mechanism, reducing the cost of the powder spreading mechanism, and making it unnecessary for the powder spreading mechanism to set up another power source and transmission mechanism to drive the powder feeding roller to rotate. Therefore, the powder spreading mechanism of the present application takes into account both the simple structural design and the guarantee of the powder spreading quality of the powder material.

[0007] In one possible implementation:

[0008] There are two powder pressing rollers, which are respectively arranged on both sides of the powder outlet; there are two transmission assemblies, which are respectively connected to the powder feeding roller through one transmission assembly.

[0009] In one possible implementation:

[0010] The powder spreading mechanism also includes a powder spreading arm, which is V-shaped. The corner of the powder spreading arm is connected to the powder feeding roller. The two powder pressing rollers are rotatably connected to the two ends of the powder spreading arm respectively. The powder spreading arm can rotate under the drive of the powder pressing rollers so that any one of the powder pressing rollers enters a lowered position away from the powder feeding roller and the other powder pressing roller enters a raised position close to the powder feeding roller.

[0011] In one possible implementation:

[0012] The powder spreading arm is rotatably engaged with the powder feeding roller; the powder spreading mechanism also includes an elastic member, which elastically presses the powder spreading arm against the powder feeding roller, so that the powder spreading arm can rotate with the powder feeding roller under the action of the friction force between the powder feeding roller and the powder spreading arm.

[0013] In one possible implementation:

[0014] The hopper is provided with a connecting ear; the powder feeding roller is inserted through the connecting ear, the powder feeding roller is provided with a stop portion, the stop portion and the connecting ear are spaced apart along the axial direction of the powder feeding roller, the powder spreading arm is located between the stop portion and the connecting ear, the elastic member is elastically supported on the powder spreading arm and the connecting ear, and the powder spreading arm is elastically pressed against the stop portion.

[0015] In one possible implementation:

[0016] The stopper is respectively in transmission cooperation with the two transmission assemblies, and is used for transmitting the rotation of the powder feeding roller to the powder pressing roller, so as to drive the powder pressing roller to rotate.

[0017] In one possible implementation:

[0018] The powder spreading mechanism also includes a limiting structure, which is used to limit the extreme position of the rotation of the powder spreading arm. At the extreme position of the powder spreading arm, one of the powder pressing rollers is maintained in the tilted position, and the other powder pressing roller is maintained in the lowered position.

[0019] In one possible implementation:

[0020] The powder spreading arm includes two connecting arms connected at an angle; the limiting structure includes two limiting members, the two limiting members are respectively arranged on the material bin, the two limiting members are respectively arranged corresponding to the two connecting arms, and when any one of the connecting arms rotates to abut against the corresponding limiting member and makes the powder pressing roller connected to it enter the tilted position, the other connecting arm rotates until the powder pressing roller connected to it enters the lowered position.

[0021] In a second aspect, the present application provides an additive manufacturing device, comprising a printing substrate, the aforementioned powder spreading mechanism and a transfer assembly. The powder spreading mechanism is used to spread powder material on the printing substrate. The transfer assembly is used to drive the powder spreading mechanism to move relative to the printing substrate.

[0022] In a third aspect, the present application provides a powder spreading method, based on the aforementioned powder spreading mechanism, the powder spreading method comprises: controlling the hopper to move in a positive direction; controlling the driving member to drive the powder feeding roller to rotate in a positive direction, while driving the powder spreading arm to rotate, so that one of the powder pressing rollers enters the tilted position, and the other powder pressing roller enters the lowered position, and the powder outlet is located on one side of the powder pressing roller in the lowered position along the positive direction; the powder feeding roller rotates and drives the powder material in the hopper to fall from the powder feeding gap to the powder spreading surface, and the powder pressing roller located at the lowered position rotates to spread the powder The powder material on the surface is flattened; then the hopper is controlled to move in the reverse direction, which is opposite to the forward direction; the driving member is controlled to drive the powder feeding roller to rotate in the reverse direction, and at the same time drive the powder spreading arm to rotate, so that one of the powder pressing rollers enters the tilting position, and the other powder pressing roller enters the lowering position, and the powder outlet is located on the side of the powder pressing roller in the lowering position along the reverse direction; the powder feeding roller rotates and drives the powder material in the hopper to fall from the powder feeding gap to the powder spreading surface, and the powder pressing roller located at the lowering position rotates to flatten the powder material on the powder spreading surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0024] Figure 1 This is a schematic structural diagram of an additive manufacturing device according to an embodiment of the present application;

[0025] Figure 2 for Figure 1 A schematic diagram of the structure of the additive manufacturing device in the embodiment of the present invention when spreading powder in the forward direction, wherein one powder pressing roller of the powder spreading mechanism is in a lowered position and the other powder pressing roller is in a raised position;

[0026] Figure 3 for Figure 1 A schematic diagram of the structure of the additive manufacturing device in the embodiment of the present invention when spreading powder in the reverse direction, wherein one powder pressing roller of the powder spreading mechanism is in a lowered position and the other powder pressing roller is in a raised position;

[0027] Figure 4 This is a schematic diagram of the structure of a powder spreading mechanism according to an embodiment of the present application;

[0028] Figure 5 for Figure 4 A cross-sectional view of a part of the middle powder spreading mechanism;

[0029] Figure 6 for Figure 4 Schematic diagram of the exploded structure of the powder spreading mechanism;

[0030] Figure 7 for Figure 4 A side view of the powder spreading mechanism in FIG.

[0031] Figure 8 for Figure 4 A cross-sectional view of another part of the middle powder spreading mechanism;

[0032] Fig. 9 for Figure 4 A front view of the powder spreading mechanism in FIG.

[0033] Fig.10 for Figure 4 A bottom view of the powder spreading mechanism in FIG.

[0034] Fig.11 for Figure 4 Top view of the powder spreading mechanism.

[0035] Description of main component symbols:

[0036] Powder spreading mechanism 100 Silo 10 Powder storage chamber 11 Powder outlet 12 Connecting ear 13 Powder feeding roller 20 Roller 21 Powder feeding trough 22 Stopper 23 First rotating gear 24 Drive parts 30 Powder pressing roller 40 Rotating part 41 Second rotating gear 42 Transmission components 50 Gear Set 51 Transmission gear 52 Powder spreading arm 60 Connecting arm 61 Matching through hole 62 Elastic parts 70 Limiting structure 80 Limiting parts 81 Additive Manufacturing Equipment 200 chassis 201 Printing substrate 202 Transfer components 203 Positive direction Y1 Reverse direction Y2 DETAILED DESCRIPTION

[0037] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments.

[0038] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may also be a centered element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may also be a centered element. When an element is considered to be "set on" another element, it may be directly set on the other element or there may also be a centered element. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0039] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present application. The terms used herein in the specification of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. The term "or / and" used herein includes any and all combinations of one or more related listed items.

[0040] Some embodiments of the present application are described in detail. In the absence of conflict, the following embodiments and features of the embodiments can be combined with each other.

[0041] In some known 3D manufacturing methods, a layer of powder is solidified into a molding layer by laser melting, laser sintering or metal bonding, and a large number of molding layers are cyclically molded on the molding layer to finally complete the 3D manufacturing of the workpiece. In this type of 3D manufacturing method, it is necessary to accurately control the thickness of each powder layer and the compaction uniformity of each powder layer before molding each molding layer.

[0042] In the known technology, a scraper or roller is used to flatten and compact the powder layer. However, the scraper has a poor flattening and compacting effect in some powder spreading scenarios, and the roller needs an additional power source to drive the rotation to achieve a better flattening and compacting effect. On the basis that the powder spreading mechanism is already provided with a relevant power source for controlling the powder feeding, the number of power sources of the powder spreading mechanism will be further increased, which greatly increases the structural complexity of the powder spreading mechanism. Therefore, it is difficult for some known 3D printing devices to achieve both good powder spreading quality and simple structural design at the same time.

[0043] In view of this, if Figures 1 to 3 As shown, the embodiment of the present application provides an additive manufacturing device 200, which includes a powder spreading mechanism 100, and the powder spreading mechanism 100 can take into account a simple structural design and ensure the powder spreading quality of the powder material.

[0044] See also Figure 1 The present embodiment provides an additive manufacturing device 200, including a housing 201, a printing substrate 202, a powder spreading mechanism 100 and a transfer assembly 203. The transfer assembly 203, the printing substrate 202 and the powder spreading mechanism 100 are all arranged in the housing 201. The transfer assembly 203 is connected to the powder spreading mechanism 100 and is used to drive the powder spreading mechanism 100 to move relative to the printing substrate 202 to spread powder on the printing substrate 202. The transfer assembly 203 can be a linear motor, a linear cylinder or other linear modules.

[0045] See also Figure 4 The powder spreading mechanism 100 includes a silo 10 , a powder feeding roller 20 , a driving member 30 and a powder pressing roller 40 .

[0046] The silo 10 defines a powder storage chamber 11 with an opening at the top, and a powder outlet 12 communicating with the powder storage chamber 11 is disposed at the bottom of the silo 10 , so that the powder material in the powder storage chamber 11 can be discharged from the powder outlet 12 .

[0047] See also Figure 5 , the powder feeding roller 20 is matched with the powder outlet 12. The powder feeding roller 20 includes a roller body 21, and the outer peripheral surface of the roller body 21 is provided with a plurality of powder feeding grooves 22 distributed along the circumferential direction, and the length direction of the powder feeding grooves 22 is parallel to the length direction of the powder feeding roller 20. A portion of the roller body 21 in the radial direction extends into the powder outlet 12, and the powder feeding grooves 22 of this portion store the powder material of the powder storage chamber 11, and the outer peripheral surface of the roller body 21 is tangent to the side of the two side surfaces opposite to the powder outlet 12 that are arranged away from the powder storage chamber 11. When the powder feeding roller 20 stops working, the portion of the powder feeding roller 20 without the powder feeding grooves 22 abuts against the two sides of the powder outlet 12, thereby closing the powder outlet 12 to keep the powder material in the powder storage chamber 11. During the rotation of the powder feeding roller 20, the powder feeding groove 22 of the powder feeding roller 20 located inside the powder outlet 12 gradually rotates to the outside of the powder storage chamber 11, and discharges the powder material in the powder feeding groove 22, completing the powder dropping action; the powder feeding groove 22 of the powder feeding roller 20 located outside the powder outlet 12 gradually rotates to the inside of the powder storage chamber 11, and receives the powder material in the powder storage chamber 11, completing the powder receiving action, so as to discharge the powder material after rotating to the outside of the powder storage chamber 11. In this way, the uninterrupted spreading action of the powder material can be achieved by the continuous rotation of the powder feeding roller 20. In this embodiment, the powder receiving capacity of the powder feeding grooves 22 of different powder feeding rollers 20 is different, which can be specifically reflected in the different shapes of the powder feeding grooves 22, the different sizes of the powder feeding grooves 22, etc. In this way, different powder feeding rollers 20 can be replaced according to actual powder feeding needs, and the real-time powder feeding amount of the powder feeding roller 20 can be obtained by obtaining the powder receiving capacity of the powder feeding groove 22 of the powder feeding roller 20, the distribution of multiple powder feeding grooves 22 on the powder feeding roller 20, the rotation speed of the powder feeding roller 20, etc., and the rotation speed of the powder feeding roller 20 can also be adjusted according to the required powder feeding amount.

[0048] The driving member 30 is connected to the powder feeding roller 20 and is used to drive the powder feeding roller 20 to rotate. In this embodiment, the driving member 30 includes but is not limited to a motor.

[0049] The powder pressing roller 40 is connected to the powder feeding roller 20 through the transmission assembly 50 and can rotate under the drive of the powder feeding roller 20 .

[0050] When the powder spreading mechanism 100 of this embodiment is working, the driving member 30 drives the powder feeding roller 20 to rotate, and drives the powder material in the silo 10 to rotate synchronously until it is discharged from the powder outlet 12, thereby completing the powder falling action of the powder material. During the rotation of the powder feeding roller 20, the transmission assembly 50 also drives the powder feeding roller 20 to rotate. After the powder material falls on the powder spreading surface, the rotating powder feeding roller 20 can flatten the powder material and fluidize the powder material to improve the uniformity of the pressed powder material and the density of the powder material, thereby improving the powder spreading quality of the powder material, which is conducive to improving the molding quality of the forming layer of the additive manufacturing. At the same time, the power sources of the powder feeding roller 20 and the powder pressing roller 40 are all from the same driving member 30, thereby saving the number of power sources of the powder spreading mechanism 100, reducing the cost of the powder spreading mechanism 100, and making it unnecessary for the powder spreading mechanism 100 to set up another power source and transmission mechanism to drive the powder feeding roller 20 to rotate. Therefore, the powder spreading mechanism 100 of this embodiment takes into account the simple structural design and ensures the powder spreading quality of the powder material.

[0051] Further, see Figures 2 to 4 There are two powder pressing rollers 40 , which are respectively arranged on both sides of the powder outlet 12 ; there are two transmission assemblies 50 , which are respectively connected to the powder feeding roller 20 through a transmission assembly 50 .

[0052] See also Figure 2 When the powder spreading mechanism 100 moves in the positive direction Y1, the powder spreading mechanism 100 can be spread by the powder pressing roller 40 (i.e. Figure 2 The powder pressing roller 40 on the right side of the middle compacts the powder material laid by the powder feeding roller 20; see Figure 3 When the powder spreading mechanism 100 moves in the reverse direction Y2, the powder spreading mechanism 100 can pass through the powder pressing roller 40 (i.e. Figure 3 The powder pressing roller 40 on the left side of the middle compacts the powder material laid again by the powder feeding roller 20. In this way, when the powder spreading mechanism 100 reciprocates from both sides of the printing substrate 202, each movement can compact a layer of powder material, thereby further improving the powder spreading efficiency.

[0053] In this embodiment, see Figures 4 to 6 The powder spreading mechanism 100 also includes a powder spreading arm 60, which is V-shaped. The corners of the powder spreading arm 60 are connected to the powder feeding roller 20. The two powder pressing rollers 40 are rotatably connected to the two ends of the powder spreading arm 60. The powder spreading arm 60 can rotate under the drive of the powder pressing rollers 40, so that any one of the powder pressing rollers 40 enters a lowered position away from the powder feeding roller 20 and the other powder pressing roller 40 enters a raised position close to the powder feeding roller 20.

[0054] When one powder pressing roller 40 is in the lowered position, the powder pressing roller 40 is away from the powder feeding roller 20 and close to the printing substrate 202, so as to compact the powder material on the printing substrate 202. At the same time, the other powder pressing roller 40 is in the raised position, close to the powder feeding roller 20 and away from the printing substrate 202, so as to avoid the powder pressing roller 40 interfering with the powder spreading action and the powder pressing action during the movement of the powder spreading mechanism 100. The position switching of the two powder pressing rollers 40 can be achieved by the powder spreading arm 60 to ensure that when the powder spreading mechanism 100 moves in the forward direction Y1 or the reverse direction Y2, only the powder pressing roller 40 in the lowered position can complete the powder material compaction action. In other embodiments, the lengths of the two powder spreading arms 60 can be the same or different.

[0055] In this embodiment, see Figure 4 The powder spreading arm 60 includes two connecting arms 61 connected at an angle, so that the powder spreading arm 60 forms a V shape.

[0056] In this embodiment, see Figure 4 and Figure 6 , two powder spreading arms 60 are provided, and the two powder spreading arms 60 are respectively connected to the two ends of the powder feeding roller 20 along the length direction thereof, so as to stably and reliably support the powder feeding roller 20. In other embodiments, if only one powder spreading arm 60 is provided, the powder feeding roller 20 can also be stably supported by lengthening the size of the powder spreading arm 60 in the length direction of the powder feeding roller 20.

[0057] In this embodiment, refer to Figure 7 and Figure 8 The powder spreading arm 60 is rotatably engaged with the powder feeding roller 20; the powder spreading mechanism 100 also includes an elastic member 70, which elastically presses the powder spreading arm 60 against the powder feeding roller 20, so that the powder spreading arm 60 can rotate with the powder feeding roller 20 under the action of the friction force between the powder feeding roller 20 and the powder spreading arm 60.

[0058] When the driving member 30 does not drive the powder feeding roller 20 to rotate, after the elastic member 70 elastically presses the powder spreading arm 60 against the powder feeding roller 20, the powder spreading arm 60 applies an elastic force perpendicular to the contact surface between the two to the powder feeding roller 20, and the elastic force generates friction between the contact surfaces of the powder spreading arm 60 and the powder feeding roller 20. After the driving member 30 drives the powder feeding roller 20 to rotate, the powder feeding roller 20 can drive the powder spreading arm 60 to rotate synchronously through the friction force. After the powder spreading arm 60 rotates to a powder pressing roller 40 in the lowered position, a force can be applied to the powder spreading arm 60, the direction of the force is different from the direction of the friction force, and the magnitude of the force component in the direction opposite to the direction of the friction force is greater than the magnitude of the friction force, so that the friction force cannot drive the powder spreading arm 60 to continue to rotate, so that the driving member 30 can still drive the powder feeding roller 20 to rotate and complete the powder dropping action, and the powder spreading arm 60 remains in a state where the powder pressing roller 40 is in the lowered position, and the powder feeding roller 20 can also drive the powder pressing roller 40 to rotate through the transmission assembly 50, so that the powder pressing roller 40 can better perform the powder pressing action. In this way, through the ingenious design of the elastic member 70, the powder spreading arm 60, and the powder feeding roller 20, the power output by the driving member 30 can also synchronously drive the powder spreading arm 60 to rotate, realizing the multiple uses of the driving force output by the driving member 30, and further simplifying the overall structure of the powder spreading mechanism 100.

[0059] In this embodiment, the elastic member 70 is a spring. In other embodiments, the elastic member 70 may also be an air spring or an elastic sleeve. In other embodiments, a small motor may be provided in the silo 10, and a pressing block may be provided at the output end of the small motor. When the powder spreading arm 60 needs to be rotated, the small motor is controlled to push the pressing block to linearly press against the powder feeding roller 20. The small motor has a low cost.

[0060] In this embodiment, see Figure 6 and Figure 8 The silo 10 is provided with a connecting ear 13; the powder feeding roller 20 is inserted into the connecting ear 13, and the powder feeding roller 20 is provided with a stopper 23, and the stopper 23 and the connecting ear 13 are spaced apart along the axial direction of the powder feeding roller 20, and the powder spreading arm 60 is located between the stopper 23 and the connecting ear 13, and the elastic member 70 is elastically supported on the powder spreading arm 60 and the connecting ear 13, and the powder spreading arm 60 is elastically pressed against the stopper 23.

[0061] Specifically, the elastic member 70 is sleeved on the powder feeding roller 20, which can ensure the installation stability of the elastic member 70, and there is no need to set up an additional fixing structure of the elastic member 70, further simplifying the overall structure of the powder spreading mechanism 100. The connecting ear 13 can facilitate the installation of the powder feeding roller 20. In other embodiments, if the powder feeding roller 20 is installed in the silo 10, the connecting ear 13 does not need to be provided, and the elastic member 70 can be elastically supported between the powder spreading arm 60 and the silo 10.

[0062] In this embodiment, see Figure 8 The powder spreading arm 60 is provided with a matching through hole 62, and the powder feeding roller 20 is inserted into the matching through hole 62. Specifically, the outer peripheral surface of the powder feeding roller 20 is in contact with the surface of the matching through hole 62, so as to ensure that when the powder feeding roller 20 drives the powder spreading arm 60 to rotate, the powder spreading arm 60 is not prone to shaking up and down, thereby ensuring that the lowering position of the powder pressing roller 40 is accurate and reliable.

[0063] Alternatively, see Figure 6 , two connecting ears 13 are provided, and the two connecting ears 13 are spaced apart at the two ends of the silo 10 along the axial direction of the powder feeding roller 20, and the two ends of the powder feeding roller 20 are respectively penetrated by the two connecting ears 13, so that the powder feeding roller 20 is stably and reliably supported by the two connecting ears 13. In other embodiments, only one connecting ear 13 may be provided, and by increasing its size in the axial direction of the powder feeding roller 20, a single connecting ear 13 can stably support the powder feeding roller 20.

[0064] In other embodiments, the powder feeding roller 20 may not need to be provided with the stopper 23, so that a gap is set between the matching through hole 62 and the powder feeding roller 20, and an elastic member 70 such as an elastic sleeve is sleeved in the gap, and the elastic sleeve abuts between the surface of the matching through hole 62 and the outer surface of the powder feeding roller 20. In this way, the elastic sleeve can also provide friction between the powder feeding roller 20 and the powder spreading arm 60, so that the rotation of the powder feeding roller 20 drives the powder spreading arm 60 to rotate.

[0065] In this embodiment, see Figures 9 to 11 The stopper 23 is respectively in transmission cooperation with the two transmission assemblies 50, and is used to transmit the rotation of the powder feeding roller 20 to the powder pressing roller 40, so as to drive the powder pressing roller 40 to rotate. By making the stopper 23 in transmission cooperation with the transmission assembly 50, it is not necessary to set an additional structure on the powder feeding roller 20 to cooperate with the transmission assembly 50, which can further simplify the overall structure of the powder feeding roller 20 and reduce its processing difficulty. In other embodiments, according to the specific structural setting of the transmission assembly 50, an additional transmission structure can also be set at the powder feeding roller 20 and cooperate with the transmission assembly 50.

[0066] In this embodiment, see Fig. 9 and Fig.10 The powder pressing roller 40 is connected to a rotating part 41 , and the transmission assembly 50 cooperates with the rotating part 41 to drive the rotating part 41 to rotate under the drive of the stopper 23 , thereby driving the powder pressing roller 40 to rotate.

[0067] In this embodiment, see Fig. 9 and Fig.10 The stopper 23 includes a first rotating gear 24, the rotating part 41 includes a second rotating gear 42, and the transmission assembly 50 includes a gear set 51, which is respectively meshed with the first rotating gear 24 and the second rotating gear 42.

[0068] In this embodiment, see Fig. 9 and Fig.10 The gear set 51 includes an odd number of transmission gears 52 meshing in sequence, so that the rotation direction of the first rotating gear 24 is the same as the rotation direction of the second rotating gear 42. When the powder feeding roller 20 drives the first rotating gear 24 to rotate clockwise, the powder spreading arm 60 rotates clockwise and causes Fig. 9 The right side of the powder pressing roller 40 enters the lowered position. At this time, the powder spreading mechanism 100 moves in the positive direction Y1, so that the right side of the powder pressing roller 40 can compact the powder material output by the powder feeding roller 20. On this basis, the rotation direction of the right side of the powder pressing roller 40 is the same as the rotation direction of the second rotating gear 42, both of which are clockwise, which can improve the powder pressing quality of the powder material. When the powder feeding roller 20 drives the first rotating gear 24 to rotate counterclockwise, the powder spreading arm 60 rotates counterclockwise and makes Fig.10 The powder pressing roller 40 on the left side enters the lowered position, and the powder spreading mechanism 100 moves in the reverse direction Y2, so that the powder pressing roller 40 on the left side can compact the powder material output by the powder feeding roller 20. On this basis, the rotation direction of the powder pressing roller 40 on the left side is the same as the rotation direction of the second rotating gear 42, both of which are counterclockwise, which can improve the powder pressing quality of the powder material. In addition, in this embodiment, by adjusting the number of transmission gears 52 of the gear set 51, the spacing between the powder feeding roller 20 and the powder pressing roller 40 can also be achieved, so as to facilitate application to different powder spreading scenes and improve the application range of the powder spreading mechanism 100.

[0069] In other embodiments, the gear set 51 may also include an even number of transmission gears 52 meshing in sequence.

[0070] In other embodiments, the stopper 23 and the rotating part 41 can be respectively set as synchronous wheels, and the transmission assembly 50 can be set as a synchronous pulley assembly connected between the two synchronous wheels. The synchronous pulley assembly can also realize the transmission function and can also realize the consistent rotation direction of the stopper 23 and the transmission part.

[0071] In this embodiment, see Fig. 9 The powder spreading mechanism 100 further includes a limiting structure 80, which is used to limit the extreme position of the rotation of the powder spreading arm 60. At the extreme position of the powder spreading arm 60, one of the powder pressing rollers 40 is kept in the raised position, and the other powder pressing roller 40 is kept in the lowered position. The limiting structure 80 can apply a force to the powder spreading arm 60, so that the powder feeding roller 20 can overcome the friction between the powder spreading arm 60 and the powder feeding roller 20 under the action of the driving member 30, and continue to rotate and drive the powder pressing roller 40 to rotate, and the powder feeding roller 20 can also continue to apply a force to the powder spreading arm 60, so that the powder spreading arm 60 is kept in the limited extreme position, so that one of the powder pressing rollers 40 is kept in the lowered position, and the powder pressing roller 40 is prevented from tilting during the powder compaction process.

[0072] In this embodiment, see Fig. 9 The limiting structure 80 includes two limiting members 81, which are respectively arranged on the silo 10. The two limiting members 81 are respectively arranged corresponding to the two connecting arms 61, and when any one connecting arm 61 rotates to abut against the corresponding limiting member 81 and makes the powder pressing roller 40 connected thereto enter the tilting position, the other connecting arm 61 rotates until the powder pressing roller 40 connected thereto enters the lowering position. Specifically, the limiting member 81 is arranged to protrude from the side of the silo 10. The limiting member 81 can be arranged on the side of the connecting arm 61 away from the printing substrate 202. In other embodiments, the limiting protrusion can also be connected to the silo 10 and located on the side of the connecting arm 61 close to the printing substrate 202.

[0073] In other embodiments, the limiting structure 80 can also be formed as a limiting bar, which is arranged on the side of the silo 10. The length direction of the limiting bar is parallel to the surface of the printing substrate 202. When the powder spreading arm 60 rotates, one of the two connecting arms 61 can rotate to contact one of the two ends of the limiting bar, thereby being limited to the extreme position.

[0074] In other embodiments, the limiting structure 80 can also be set as an electromagnet, which is arranged on the side of the silo 10, and magnets or iron blocks are respectively arranged on the two connecting arms 61, so that the powder spreading arm 60 can be driven to rotate by the suction force between the electromagnet and the magnet or iron block, and one connecting arm 61 can be kept in the extreme position.

[0075] The present embodiment also provides a powder spreading method, based on the aforementioned powder spreading mechanism 100, the powder spreading method comprises: controlling the silo 10 to move along the positive direction Y1; controlling the driving member 30 to drive the powder feeding roller 20 to rotate positively, and at the same time driving the powder spreading arm 60 to rotate, so that one powder pressing roller 40 enters the tilting position, and the other powder pressing roller 40 enters the lowering position, and the powder outlet 12 is located at the side of the powder pressing roller 40 in the lowering position along the positive direction Y1; the powder feeding roller 20 rotates and drives the powder material in the silo 10 to fall from the powder feeding gap to the powder spreading surface, and the powder pressing roller 40 in the lowering position rotates to spread the powder The powder material on the powder surface is flattened; then the silo 10 is controlled to move in the reverse direction Y2, which is opposite to the forward direction Y1; the driving member 30 is controlled to drive the powder feeding roller 20 to rotate in the reverse direction, and at the same time drive the powder spreading arm 60 to rotate, so that one powder pressing roller 40 enters the tilting position, and the other powder pressing roller 40 enters the lowered position, and the powder outlet 12 is located on the side of the powder pressing roller 40 in the lowered position along the reverse direction Y2; the powder feeding roller 20 rotates and drives the powder material in the silo 10 to fall from the powder feeding gap to the powder spreading surface, and the powder pressing roller 40 located in the lowered position rotates to flatten the powder material on the powder spreading surface.

[0076] By performing the powder laying action of the powder material by the powder laying method of the present embodiment, the powder material can be laid once during the reciprocating motion of the powder laying mechanism 100, thereby improving the powder laying efficiency of the powder laying mechanism 100, and the powder pressing roller 40 compacts the powder material during each laying process, thereby ensuring the laying quality of the powder material, and ultimately improving the printing efficiency and printing quality.

[0077] The above implementation modes are only used to illustrate the technical solutions of the present application and are not intended to limit the present application. Although the present application has been described in detail with reference to the above preferred implementation modes, a person skilled in the art should understand that the technical solutions of the present application may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present application.

Claims

1. A powder spreading mechanism, characterized in that: include: A silo, wherein the silo is provided with a powder outlet; A powder feeding roller, the powder feeding roller is matched with the powder outlet; A driving member, the driving member is connected to the powder feeding roller and is used to drive the powder feeding roller to rotate; A powder pressing roller is connected to the powder feeding roller through a transmission assembly and can rotate under the drive of the powder feeding roller.

2. The powder spreading mechanism according to claim 1, characterized in that: There are two powder pressing rollers, which are respectively arranged on both sides of the powder outlet; there are two transmission assemblies, which are respectively connected to the powder feeding roller through one transmission assembly.

3. The powder spreading mechanism according to claim 2, characterized in that: The powder spreading mechanism also includes a powder spreading arm, which is V-shaped. The corner of the powder spreading arm is connected to the powder feeding roller. The two powder pressing rollers are rotatably connected to the two ends of the powder spreading arm respectively. The powder spreading arm can rotate under the drive of the powder pressing rollers so that any one of the powder pressing rollers enters a lowered position away from the powder feeding roller and the other powder pressing roller enters a raised position close to the powder feeding roller.

4. The powder spreading mechanism according to claim 3, characterized in that: The powder spreading arm is rotatably engaged with the powder feeding roller; the powder spreading mechanism also includes an elastic member, which elastically presses the powder spreading arm against the powder feeding roller, so that the powder spreading arm can rotate with the powder feeding roller under the action of the friction force between the powder feeding roller and the powder spreading arm.

5. The powder spreading mechanism according to claim 4, characterized in that: The silo is provided with a connecting ear; The powder feeding roller is inserted into the connecting ear, and the powder feeding roller is provided with a stop portion. The stop portion and the connecting ear are spaced apart along the axial direction of the powder feeding roller, and the powder spreading arm is located between the stop portion and the connecting ear. The elastic member is elastically supported on the powder spreading arm and the connecting ear, and the powder spreading arm is elastically pressed against the stop portion.

6. The powder spreading mechanism according to claim 5, characterized in that: The stopper is respectively in transmission cooperation with the two transmission assemblies, and is used for transmitting the rotation of the powder feeding roller to the powder pressing roller, so as to drive the powder pressing roller to rotate.

7. The powder spreading mechanism according to claim 3, characterized in that: The powder spreading mechanism also includes a limiting structure, which is used to limit the extreme position of the rotation of the powder spreading arm. At the extreme position of the powder spreading arm, one of the powder pressing rollers is maintained in the tilted position, and the other powder pressing roller is maintained in the lowered position.

8. The powder spreading mechanism according to claim 7, characterized in that: The powder spreading arm comprises two connecting arms connected at an angle; The limiting structure includes two limiting members, which are respectively arranged on the material bin, and the two limiting members are respectively arranged corresponding to the two connecting arms, and when any one of the connecting arms rotates to abut against the corresponding limiting member and makes the powder pressing roller connected to it enter the tilted position, the other connecting arm rotates until the powder pressing roller connected to it enters the lowered position.

9. An additive manufacturing device, characterized in that: include: Printing substrate; The powder spreading mechanism according to any one of claims 1 to 8, wherein the powder spreading mechanism is used to spread powder material onto the printing substrate; A transfer assembly is used to drive the powder spreading mechanism to move relative to the printing substrate.

10. A powder spreading method, characterized in that: Based on the powder spreading mechanism according to claim 3, the powder spreading method comprises: Controlling the silo to move in a forward direction; Control the driving member to drive the powder feeding roller to rotate in the forward direction, and at the same time drive the powder spreading arm to rotate, so that one of the powder pressing rollers enters the tilted position, the other powder pressing roller enters the lowered position, and the powder outlet is located on one side of the powder pressing roller in the lowered position along the forward direction; The powder feeding roller rotates and drives the powder material in the silo to fall from the powder feeding gap to the powder spreading surface, and the powder pressing roller located at the lowering position rotates to flatten the powder material on the powder spreading surface; Then controlling the silo to move in a reverse direction, wherein the reverse direction is opposite to the forward direction; Control the driving member to drive the powder feeding roller to rotate in the opposite direction, and at the same time drive the powder spreading arm to rotate, so that one of the powder pressing rollers enters the tilting position, the other of the powder pressing rollers enters the lowered position, and the powder outlet is located on one side of the powder pressing roller at the lowered position along the reverse direction; The powder feeding roller rotates and drives the powder material in the silo to fall from the powder feeding gap to the powder spreading surface, and the powder pressing roller located at the lowering position rotates to flatten the powder material on the powder spreading surface.

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