Bidirectional powder spreading device for additive manufacturing equipment

Abstract

The utility model relates to the technical field of additive manufacturing, in particular to a bidirectional powder spreading device for additive manufacturing equipment, which has the characteristics of capability of accurately controlling the front and back powder feeding amount of a scraper and good powder feeding stability. Comprising a rack, at least one driving mechanism, two first guide mechanisms, two second guide mechanisms, two connecting seats, a supporting seat, a first powder box, a second powder box, a scraper mechanism, a first positioning mechanism and a second positioning mechanism, the two first guide mechanisms are arranged on the two transverse sides of the rack correspondingly, and the two connecting seats are arranged on the two first guide mechanisms correspondingly; the driving mechanism is connected with the connecting seats, the supporting seat is erected on the two connecting seats in the transverse direction, the upper surface of the supporting seat is provided with a supporting plane, the scraper mechanism is arranged at the lower end of the supporting seat, the first powder box is arranged at the front end of the supporting seat, and the second powder box is distributed at the rear end of the supporting seat and comprises a powder storage bin and a powder guide bin. And the two second guide mechanisms are respectively arranged on the connecting seat.

Description

Technical Field

[0001] This utility model relates to the field of additive manufacturing technology, and in particular to a bidirectional powder spreading device for additive manufacturing equipment. Background Technology

[0002] Additive manufacturing technology is an advanced manufacturing technology with distinctive characteristics such as digital manufacturing, high flexibility and adaptability, direct CAD model driving, speed, and a wide variety of material types. Because it is not limited by the complexity of the part shape and does not require any tooling or molds, its application range is very wide. Selective laser sintering (SLS), one of the additive manufacturing technologies, has also developed very rapidly in recent years. Its main process is as follows: a powder feeding device delivers a certain amount of powder to the worktable, a powder spreading device spreads a layer of powder material evenly on the upper surface of the piston-shaped part, and a galvanometer-controlled laser scans the solid powder layer according to the cross-sectional profile of the layer, raising the powder temperature to the melting point. The powder melts and sinters, bonding with the already formed part below. After one cross-section is sintered, the worktable lowers by one layer thickness, and the powder spreading device spreads another layer of uniform and dense powder on top, and a new cross-section is scanned and sintered. This process is repeated for several layers until the entire three-dimensional solid is manufactured.

[0003] Traditional powder spreading devices are mostly unidirectional structures, requiring a return to the powder supply position (i.e., the powder dropping device) after each spreading operation, resulting in long spreading times and low efficiency. Patent application publication number CN111376474A discloses a powder dropping and bidirectional powder spreading device suitable for additive manufacturing. This device, from top to bottom, includes a powder supply device, a working chamber top plate, a powder dropping valve, a powder spreading device, and a working panel. A forward-leaning ejector and a reverse-leaning ejector are respectively located at the rear and front of the powder spreading device. The powder dropping valve is fixed to a powder dropping valve fixing plate, which is fixed via the working chamber top plate. Holes are provided in the middle of both the working chamber top plate and the powder dropping valve fixing plate, with the upper part of the holes connecting to the interior of the powder supply device. One end of the powder dropping valve connects to the hole, and the other end connects to the powder spreading device. The powder spreading device includes a housing, a height adjustment assembly, and a scraper assembly. The height adjustment assembly is located on both sides of the housing. The scraper assembly is located below the housing, and the height adjustment assembly is connected to the scraper assembly. The housing contains a powder-distributing block, an upper powder outlet in the center of the top, and a lower cover and a powder-discharging control plate at the bottom. The powder-distributing block is triangular in shape, with its apex located at the center of the upper powder outlet. The bottom of the powder-distributing block is fixed to the lower cover, and the width of the bottom of the powder-distributing block is less than the width of the lower cover. The lower cover has a front powder outlet and a rear powder outlet at its front and rear ends, respectively. The powder-discharging control plate is located below the lower cover and is movably connected to the housing via two scraper blades. The powder-discharging control plate has a front powder outlet and a rear powder outlet. In non-working conditions, the front powder outlet and the front powder outlet are staggered, and the rear powder outlet and the rear powder outlet are staggered.

[0004] The aforementioned patent uses a slotted toner separator plate. When the scraper reaches its front and rear limits, a spring device pushes the toner separator plate to align the originally misaligned slots, allowing powder to be dispensed. However, due to the large contact area and limited freedom of the toner separator plate with the upper and lower plates, if the installation gap is too small, the powder may easily stick together after absorbing moisture, leading to excessive friction and insufficient powder dispensing. If the gap is too large, the powder may easily be shaken off during the scraper's movement. Furthermore, the device requires a high degree of horizontal stability, which is not ideal. In addition, this device generally uses a mechanical structure to evenly distribute the powder from the upper toner dispenser to the front and rear of the toner plate. This solution is only theoretically evenly distributed and cannot accurately control the amount of powder fed to the front and rear. Equipment installation errors and powder jamming can easily lead to inconsistent powder amounts at the front and rear, causing printing failures. Utility Model Content

[0005] Therefore, in view of the above problems, this utility model provides a bidirectional powder spreading device for additive manufacturing equipment that can accurately control the amount of powder fed before and after the scraper and has good powder spreading stability.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A bidirectional powder spreading device for additive manufacturing equipment includes a frame, at least one drive mechanism, two first guide mechanisms, two second guide mechanisms, two connecting seats, a support seat, a first powder box, a second powder box, a scraper mechanism, a first positioning mechanism, and a second positioning mechanism. The longitudinal direction is defined as extending along the length direction of the frame, and the transverse direction is defined as extending along the width direction of the frame. The frame has a front end and a rear end located at both ends of the longitudinal direction.

[0008] Two first guiding mechanisms are respectively disposed on the transverse sides of the frame. Each first guiding mechanism includes a first guide rail and a first slider disposed on the first guide rail. Two connecting seats are respectively disposed on the two first guiding mechanisms. The driving mechanism is connected to the connecting seats and is used to drive the connecting seats to move along the longitudinal direction of the first guiding mechanisms. A support seat is mounted on the two connecting seats in the transverse direction. The upper surface of the support seat has a supporting plane. The scraper mechanism is disposed at the lower end of the support seat. The first powder box is disposed at the front end of the support seat. The first powder box has a first powder inlet distributed at the upper end and... The first powder outlet is located at the lower end, and the second powder box is located at the rear end of the support base. The second powder box includes a powder storage compartment and a powder guide compartment. Two second guide mechanisms are respectively located on the connecting base. The powder storage compartment is mounted on the two second guide mechanisms in the transverse direction. The powder storage compartment has a second powder inlet located at the upper end and a second powder outlet located at the lower end. The powder guide compartment is located at the rear end of the support base. The powder guide compartment has a third powder inlet located at the upper end and a third powder outlet located at the lower end. The first positioning mechanism is located at the front end of the frame, and the second positioning mechanism is located at the rear end of the frame.

[0009] When the powder storage bin is at the front end of the second guiding mechanism, the second powder outlet of the powder storage bin abuts against the supporting plane; when the powder storage bin is at the rear end of the second guiding mechanism, the second powder outlet of the powder storage bin is connected to the third powder inlet of the powder guiding bin.

[0010] Furthermore, the second guiding mechanism includes a second guide rail and a second slider disposed on the second guide rail. A top block is provided between the second slider and the powder storage bin. When the support is at the front end of the first guiding mechanism, the front end of the top block abuts against the first positioning mechanism; when the support is at the rear end of the first guiding mechanism, the rear end of the top block abuts against the second positioning mechanism.

[0011] Furthermore, the scraper mechanism includes a scraper base locked to the support seat, a first clamping plate fixed to the scraper base, a second clamping plate locked to the first clamping plate, two side plates respectively locked to the transverse two sides of the scraper base, and a scraper. The inner sides of the two side plates are vertically provided with protruding plates at their longitudinal center. The lower ends of the first clamping plate and the facing surfaces of the second clamping plate are both recessed with clamping grooves. The scraper is embedded in the clamping grooves, and the transverse two ends of the scraper abut against the protruding plates.

[0012] Furthermore, the outer edges of the lower ends of both the first clamping plate and the second clamping plate are provided with rounded corners.

[0013] Furthermore, both of the side plates are provided with a powder scraper on their outer surfaces.

[0014] Furthermore, the front end of the support base is provided with a powder guiding groove.

[0015] Furthermore, a powder guide plate is provided at the front end of the support base and on the upper side of the powder guide groove. The lower surface of the rear end of the powder guide plate is recessed with a relief groove that communicates with the powder guide groove. An inclined powder guide surface is provided on the side of the powder guide plate near the first powder box. A through groove communicating with the powder guide groove is provided at the lower part of the powder guide surface.

[0016] Furthermore, the front and rear ends of the frame are equipped with powder cleaning brushes.

[0017] Furthermore, the drive mechanism includes a ball screw mounted on the first guide mechanism and a drive motor connected to one end of the ball screw.

[0018] Furthermore, there are two drive mechanisms, and each drive mechanism is connected to a separate connecting seat.

[0019] By adopting the aforementioned technical solution, the beneficial effects of this utility model are as follows: This bidirectional powder spreading device for additive manufacturing equipment uses a first powder box and a second powder box that are independently set. The second powder box includes a powder storage bin and a powder guiding bin. In use, the drive mechanism drives the first and second powder boxes on the support base to the rear end and to the lower side of the powder dispensing device. At this time, the second powder outlet of the powder storage bin of the second powder box abuts against the support plane, that is, the second powder outlet is closed. Then, the powder dispensing device above independently supplies powder in a quantitative manner. After the powder is filled, the drive mechanism drives the support base to move to the front end along the guiding direction of the first guiding mechanism. At this time, the powder in the first powder box falls and is evenly spread by the scraper mechanism. When the support base is driven to the front end, the top block abuts against the first positioning mechanism, pushing the powder storage bin to move to the rear end along the guiding direction of the second guiding mechanism, so that the second powder outlet of the powder storage bin... The powder inlet is connected to the third powder inlet of the powder guide chamber. The support base is then driven by the drive mechanism to move to the front end along the guide direction of the first guide mechanism. At this time, the powder in the powder storage chamber of the second powder box falls and is evenly spread by the scraper mechanism. When the support base is driven to the rear end, the top block abuts against the second positioning mechanism, pushing the powder storage chamber to move to the front end along the guide direction of the second guide mechanism. At this time, the second powder outlet of the powder storage chamber of the second powder box abuts against the support plane. This process is repeated to achieve bidirectional powder spreading. This design allows the first and second powder boxes to be filled separately, which can more accurately control the amount of powder spread in front and behind. This is beneficial for saving powder and controlling powder. It also helps to change the amount of powder spread in each layer at any time when the layer thickness function is used. This allows the first and second powder boxes to accurately dispense powder separately, and the powder dispensing stability is good. At the same time, the single scraper mechanism has a simple structure, is easy to replace and adjust, and has low operating costs. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of the support base located at the front end of the first guide mechanism in an embodiment of this utility model;

[0021] Figure 2This is a schematic diagram of the support base positioned at the front end of the first guide mechanism in an embodiment of this utility model where a drive mechanism is omitted;

[0022] Figure 3 This is a schematic diagram of the support base located at the rear end of the first guide mechanism in an embodiment of this utility model where a drive mechanism is omitted;

[0023] Figure 4 This is a top view of the storage bin located at the front end of the second guide mechanism in an embodiment of this utility model;

[0024] Figure 5 This is a top view of the storage bin located at the rear end of the second guide mechanism in this embodiment of the utility model.

[0025] Figure 6 This is a bottom view of the storage bin located at the rear end of the second guide mechanism in an embodiment of this utility model;

[0026] Figure 7 This is a schematic diagram of the exploded structure in the first state of the present invention;

[0027] Figure 8 This is a schematic diagram of the exploded structure in the second state of this utility model embodiment;

[0028] Figure 9 This is a schematic diagram of the exploded structure in the third state of this utility model embodiment;

[0029] Figure 10 This is a three-dimensional structural diagram of the powder guiding plate in a top view in an embodiment of this utility model;

[0030] Figure 11 This is a three-dimensional structural diagram of the powder guiding plate in a bottom view in an embodiment of this utility model;

[0031] Figure 12 This is a partial cross-sectional structural schematic diagram of an embodiment of the present utility model;

[0032] Figure 13 yes Figure 12 Schematic diagram of the cross-sectional structure at point AA;

[0033] Figure 14 This is a three-dimensional structural schematic diagram of another embodiment of this utility model.

[0034] Explanation of reference numerals in the attached figures:

[0035] 1. Frame; 2. Drive mechanism; 3. First guide mechanism; 4. Second guide mechanism; 5. Connecting seat; 6. Support seat; 7. First powder box; 8. Second powder box; 9. Scraper mechanism; 10. First positioning mechanism; 11. Second positioning mechanism; 12. Top block; 13. Powder dropping device; 14. Scraper blade; 15. Filter plate; 16. Powder guide groove; 17. Powder guide plate; 18. Clearing groove; 19. Powder guide surface; 20. Through groove; 30. Cleaning brush;

[0036] 21. Ball screw; 22. Drive motor; 31. First guide rail; 32. First slider; 41. Second guide rail; 42. Second slider;

[0037] 60. Support plane; 71. First powder inlet; 72. First powder outlet; 81. Powder storage bin; 82. Powder guide bin; 83. Second powder inlet; 84. Second powder outlet; 85. Third powder inlet; 86. Third powder outlet;

[0038] 91. Scraper base; 92. First clamping plate; 93. Second clamping plate; 94. Side plate; 95. Scraper; 96. Protruding plate; 97. Clamping groove; 98. Rounded corner structure. Detailed Implementation

[0039] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments.

[0040] The embodiment of this utility model is as follows:

[0041] refer to Figures 1 to 14 As shown, a bidirectional powder spreading device for additive manufacturing equipment includes a frame 1, two drive mechanisms 2, two first guide mechanisms 3, two second guide mechanisms 4, two connecting seats 5, a support seat 6, a first powder box 7, a second powder box 8, a scraper mechanism 9, a first positioning mechanism 10, and a second positioning mechanism 11. The longitudinal direction is defined as extending along the length of the frame 1, and the transverse direction is defined as extending along the width of the frame 1. The frame has a front end and a rear end located at both ends of the longitudinal direction.

[0042] Two first guide mechanisms 3 are respectively disposed on the transverse sides of the frame 1, and two connecting seats 5 are respectively disposed on the two first guide mechanisms 3. The driving mechanism 2 is connected to the connecting seats 5 and is used to drive the connecting seats 5 to move along the longitudinal direction of the first guide mechanism 3. The support seat 6 is mounted on the two connecting seats 5 in the transverse direction. The upper surface of the support seat 6 has a supporting plane 60. The scraper mechanism 9 is disposed at the lower end of the support seat 6. The first powder box 7 is disposed at the front end of the support seat 6. The first powder box 7 has a first powder inlet 71 distributed at the upper end and a first powder outlet 72 distributed at the lower end. The second powder box 8 is divided into... The second powder box 8, located at the rear end of the support base 6, includes a powder storage chamber 81 and a powder guiding chamber 82. Two second guiding mechanisms 4 are respectively mounted on the connecting base 5. The powder storage chamber 81 is mounted on the two second guiding mechanisms 4 in a transverse direction. The powder storage chamber 81 has a second powder inlet 83 at the upper end and a second powder outlet 84 at the lower end. The powder guiding chamber 82 is located at the rear end of the support base 6. The powder guiding chamber 82 has a third powder inlet 85 at the upper end and a third powder outlet 86 at the lower end. The first positioning mechanism 10 is located at the front end of the frame 1, and the second positioning mechanism 11 is located at the rear end of the frame 1.

[0043] When the powder storage bin 81 is at the front end of the second guide mechanism 4, the second powder outlet 84 of the powder storage bin 81 abuts against the support plane 60; when the powder storage bin 81 is at the rear end of the second guide mechanism 4, the second powder outlet 84 of the powder storage bin 81 is connected to the third powder inlet 85 of the powder guide bin 82.

[0044] In this embodiment, the driving mechanism 2 includes a ball screw 21 mounted on the first guide mechanism 3 and a drive motor 22 connected to one end of the ball screw 21. The first guide mechanism 3 includes a first guide rail 31 and a first slider 32 mounted on the first guide rail 31. The second guide mechanism 4 includes a second guide rail 41 and a second slider 42 mounted on the second guide rail 41. A top block 12 is provided between the second slider 42 and the powder storage bin 81. When the support seat 6 is at the front end of the first guide mechanism 3, the front end of the top block 12 abuts against the first positioning mechanism 10. When the support seat 6 is at the rear end of the first guide mechanism 3, the rear end of the top block 12 abuts against the second positioning mechanism 11. Both the first positioning mechanism 10 and the second positioning mechanism 11 are hydraulic dampers. The drive motor 22 is a servo motor.

[0045] The aforementioned drive mechanism 2 consists of two components, each connected to a separate connecting seat 5. This optimized transmission structure provides greater rigidity and more stable operation of the powder spreading device. The use of a servo system to drive the high-precision dustproof ball screw 21 and the guide mechanism of the guide rail slider ensures high left-right synchronization accuracy and high bidirectional powder spreading consistency. It prevents phenomena such as insufficient rigidity, tilting, or left-right position deviation, and also has a high dustproof rating, allowing for long-term stable operation. Alternatively, a single drive mechanism can be used, which can also achieve the guiding function, but the stability of the powder spreading device will be relatively poor.

[0046] This bidirectional powder spreading device for additive manufacturing equipment consists of a first powder box 7 and a second powder box 8, each independently configured. The second powder box 8 includes a powder storage chamber 81 and a powder guiding chamber 82. In use, the drive mechanism 2 drives the first powder box 7 and the second powder box 8 on the support base 6 to the rear end, located below the powder dropping device 13. At this time, the second powder outlet 84 of the powder storage chamber 81 of the second powder box 8 abuts against the support plane 60, effectively closing the second powder outlet 84. The powder dropping device 13 then independently and quantitatively supplies powder. After the powder is filled, the drive mechanism 2 drives the support base 6 to move to the front end along the guiding direction of the first guiding mechanism 3. At this time, the powder in the first powder box 7 falls and is evenly spread by the scraper mechanism 9. When the support base 6 is driven to the front end, the top block abuts against the first positioning mechanism 10, pushing the powder storage chamber 81 to move to the rear end along the guiding direction of the second guiding mechanism 4, causing the second powder outlet 84 of the powder storage chamber 81 to align with the powder guiding chamber. The third powder inlet 85 of 82 is connected, and the support base 6 is driven by the drive mechanism 2 to move to the front end along the guide direction of the first guide mechanism 3. At this time, the powder in the powder storage bin 81 of the second powder box 8 falls and is evenly spread by the scraper mechanism 9. When the support base 6 is driven to the rear end, the top block 12 abuts against the second positioning mechanism 11 and pushes the powder storage bin 81 to move to the front end along the guide direction of the second guide mechanism 4. At this time, the second powder outlet 84 of the powder storage bin 81 of the second powder box 8 abuts against the support plane 60. This reciprocating action realizes the bidirectional powder spreading effect. This design allows the first powder box and the second powder box to be filled separately, which can more accurately control the amount of powder spread before and after, which is beneficial to save powder and control powder. It also helps to change the amount of powder spread in each layer at any time when the layer thickness function is changed, so that the first powder box 7 and the second powder box 8 can accurately drop powder separately, and the powder dropping stability is good. At the same time, the single scraper mechanism 9 has a simple structure, is easy to replace, easy to adjust, and has low operating cost.

[0047] Meanwhile, the powder storage bin 81 of the second powder box 8 is connected to the second guide mechanism 4 of the guide rail and slider structure at both ends in the horizontal direction, and cooperates with the first positioning mechanism 10 and the second positioning mechanism 11 set at the front and rear ends of the frame 1. After contact, it moves passively. The slider has a small coefficient of friction and moves smoothly. The powder storage bin 81 only has bottom surface friction, small contact area, good running stability and high running safety, avoiding powder jamming problems.

[0048] Furthermore, the scraper mechanism 9 includes a scraper base 91 locked to the support base 6, a first clamping plate 92 fixed to the scraper base 91, a second clamping plate 93 locked to the first clamping plate 92, two side plates 94 respectively locked to the two transverse sides of the scraper base 91, and a scraper 95. The inner sides of the two side plates 94 are vertically provided with protruding plates 96 at their longitudinal center. The lower ends of the first clamping plate 92 and the facing surfaces of the second clamping plate 93 are both recessed with clamping grooves 97. The scraper 95 is embedded in the clamping grooves 97, and the two transverse ends of the scraper 95 abut against the protruding plates 96. The outer edges of the lower ends of the first clamping plate 92 and the second clamping plate 93 are provided with rounded corner structures 98. This scraper mechanism 9 has a simple structure and high convenience for disassembling and replacing the scraper 95 and adjusting the gap, resulting in good stability of powder spreading.

[0049] Furthermore, both side plates 94 are provided with a powder scraper 14 on their outer surfaces for scraping off excess powder from both ends of the scraper 95.

[0050] Meanwhile, the front end of the support base 6 is provided with a powder guiding groove 16, and the front end of the support base 6 and the upper side of the powder guiding groove are provided with a powder guiding plate 17. The lower surface of the rear end of the powder guiding plate 17 is recessed with a relief groove 18 that communicates with the powder guiding groove. The side of the powder guiding plate 17 near the first powder box is provided with an inclined powder guiding surface 19. The lower part of the powder guiding surface 19 is provided with a through groove 20 that communicates with the powder guiding groove 16. Excess powder on the support plane 60 is squeezed out by the powder guiding groove 16 through the movement of the powder storage bin 81, so there will be no powder jamming that causes back and forth movement. In addition, excess powder is guided by the powder guiding surface 19 during material discharge and discharged by the through groove 20 and the powder guiding groove 16, improving the convenience of use.

[0051] Furthermore, the front and rear ends of the frame 1 are equipped with powder cleaning brushes 30, which can effectively prevent powder from sticking to the sides of the first clamping plate 92, the second clamping plate 93 and the scraper rubber strip mounting piece, causing it to fall off during the movement and affect the powder spreading effect.

[0052] Furthermore, the powder storage bin 81 is equipped with a powder filter plate 15, which has a number of filter holes, so that the powder can be evenly spread in the powder storage bin 81 after entering, and the amount of powder can be controlled at the same time.

[0053] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0054] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0055] In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0056] Although the present invention has been specifically shown and described in conjunction with preferred embodiments, those skilled in the art should understand that various changes in form and detail may be made to the present invention without departing from the spirit and scope of the present invention as defined in the appended claims, and all such changes shall be within the scope of protection of the present invention.

Claims

1. A bidirectional powder spreading device for an additive manufacturing apparatus, characterized by: The machine frame, at least one driving mechanism, two first guide mechanisms, two second guide mechanisms, two connecting seats, a supporting seat, a first powder box, a second powder box, a scraper mechanism, a first positioning mechanism, and a second positioning mechanism are provided, and the longitudinal direction is defined as the length direction of the machine frame, and the transverse direction is defined as the width direction of the machine frame. The two first guide mechanisms are respectively arranged on the two sides of the machine frame in the transverse direction, and each first guide mechanism comprises a first guide rail and a first sliding block arranged on the first guide rail. The two connecting seats are respectively arranged on the two first guide mechanisms, and the driving mechanism is connected with the connecting seat and used for driving the connecting seat to move along the longitudinal direction of the first guide mechanism.

2. Bidirectional powder spreading device for an additive manufacturing apparatus according to claim 1, characterized in that: The supporting seat is arranged on the two connecting seats in the transverse direction, and the upper surface of the supporting seat has a supporting plane.

3. The bidirectional powder spreading device for an additive manufacturing apparatus of claim 2, characterized in that: The scraper mechanism is arranged at the lower end of the supporting seat, the first powder box is arranged at the front end of the supporting seat, the first powder box has a first powder inlet arranged at the upper end and a first powder outlet arranged at the lower end, the second powder box is arranged at the rear end of the supporting seat, the second powder box comprises a powder storage bin and a powder guide bin, the two second guide mechanisms are respectively arranged on the connecting seats, the powder storage bin is arranged on the two second guide mechanisms in the transverse direction, the powder storage bin has a second powder inlet arranged at the upper end and a second powder outlet arranged at the lower end, the powder guide bin is arranged at the rear end of the supporting seat, the powder guide bin has a third powder inlet arranged at the upper end and a third powder outlet arranged at the lower end, the first positioning mechanism is arranged at the front end of the machine frame, and the second positioning mechanism is arranged at the rear end of the machine frame.

4. The bidirectional powder spreading device for an additive manufacturing apparatus of claim 3, characterized in that: When the powder storage bin is at the front end of the second guide mechanism, the second powder outlet of the powder storage bin abuts against the supporting plane.

5. The bidirectional powder spreading device for an additive manufacturing apparatus of claim 4, characterized in that: When the powder storage bin is at the rear end of the second guide mechanism, the second powder outlet of the powder storage bin is in communication with the third powder inlet of the powder guide bin.

6. Bidirectional powder spreading device for an additive manufacturing apparatus according to any one of claims 1 to 5, characterized in that: The second guide mechanism comprises a second guide rail and a second sliding block arranged on the second guide rail, and a top block is arranged between the second sliding block and the powder storage bin. When the supporting seat is at the front end of the first guide mechanism, the front end of the top block abuts against the first positioning mechanism. When the supporting seat is at the rear end of the first guide mechanism, the rear end of the top block abuts against the second positioning mechanism. The scraper mechanism comprises a scraper base locked to the supporting seat, a first clamping plate fixed to the scraper base, a second clamping plate locked to the first clamping plate, two side plates respectively locked to the two lateral sides of the scraper base, and a scraper. The inner side of each of the two side plates is vertically provided with a protruding plate at the longitudinal middle part. The lower end of each of the first clamping plate and the second clamping plate is outwardly provided with a rounded corner structure. The outer side of each of the two side plates is provided with a powder scraping plate. The front end of the supporting seat is provided with a powder guide groove.

7. The bidirectional powder spreading device for an additive manufacturing apparatus of claim 6, characterized in that: The front end of the support seat is provided with a powder guide plate, the lower surface of the rear end of the powder guide plate is concavely provided with a clearance slot in communication with the powder guide groove, and the powder guide plate is provided with an inclined powder guide surface near the side surface of the first powder box.

8. The bidirectional powder spreading device for an additive manufacturing apparatus of claim 7, characterized in that: The front end and the rear end of the rack are both provided with a powder cleaning brush.

9. The bidirectional powder spreading device for an additive manufacturing apparatus of claim 7, wherein: The driving mechanism comprises a ball screw arranged on the first guide mechanism and a driving motor connected with one end of the ball screw.

10. The bidirectional powder spreading device for an additive manufacturing apparatus of claim 7, wherein: The number of the driving mechanisms is two, and the two driving mechanisms are connected with the two connecting seats respectively.

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