Non-contact powder spreading device for additive manufacturing

Abstract

The application belongs to the technical field of additive manufacturing equipment, and relates to a non-contact powder spreading device for additive manufacturing, which comprises a powder storage groove, a powder controller and a control panel; the powder controller is arranged at the bottom of the powder storage groove; and the control panel is connected with the powder controller and drives the powder controller to open or close. The application can avoid the problems of knife sticking and powder sticking, and can also avoid the problems of deformation and damage of the formed part caused by scraping. The application can effectively improve the forming quality of the powder spreading type additive manufacturing equipment and is also beneficial to the realization of the non-support forming technology.

Description

Technical Field

[0001] This invention belongs to the technical field of additive manufacturing equipment, and relates to a powder spreading device, and more particularly to a non-contact powder spreading device for additive manufacturing. Background Technology

[0002] Additive manufacturing is often achieved through layer-by-layer production, which requires spreading raw materials—powder—onto the forming area according to the required thickness. Current technologies typically use contact-type powder spreading devices such as scrapers or powder spreading rollers. Both scrapers and rollers often face two problems: first, powder sticking to the spreading device; and second, direct contact between the spreading device and the already formed part during the spreading process. After powder sticking, when the powder falls into the next forming area during the return stroke of the spreading device, it often causes localized bulges or areas that are not fully burned through, both of which reduce the forming quality and may even lead to the scrapping of the formed part. The direct contact between the spreading device and the already formed part often involves forces, which can lead to localized deformation and breakage of the part, especially for thin-walled parts, severely affecting the forming quality.

[0003] In addition, as one of the development trends of additive manufacturing technology, unsupported forming technology also places new requirements on powder spreading devices. Even the contact powder spreading device such as the flexible scraper used in traditional technology is not conducive to the realization of unsupported forming technology. Summary of the Invention

[0004] In order to solve the above-mentioned technical problems in the background art, the present invention provides a non-contact powder spreading device for additive manufacturing, which can avoid the sticking of powder to the blade and scraper, and can also prevent the already formed parts from being scraped, deformed or damaged. It can effectively improve the forming quality of powder spreading additive manufacturing equipment, and is also conducive to the realization of supportless forming technology.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A non-contact powder spreading device for additive manufacturing is characterized in that: the non-contact powder spreading device for additive manufacturing includes a powder storage tank, a powder controller, and a control board; the powder controller is placed at the bottom of the powder storage tank; the control board is connected to the powder controller and drives the powder controller to open or close.

[0007] The aforementioned powder controller is one or more. When there are multiple powder controllers, the multiple powder controllers are arranged in parallel along the axial direction of the powder storage tank at the bottom of the powder storage tank.

[0008] The aforementioned powder controller includes a powder controller housing, a right electrode pin, a right piezoelectric ceramic block, a left piezoelectric ceramic block, and a left electrode pin. The powder controller housing is a cylindrical structure with openings at the top and bottom. The right and left electrode pins are positioned opposite each other and placed on the outer wall of the powder controller housing. The right and left piezoelectric ceramic blocks are positioned opposite each other and placed on the inner wall of the powder controller housing. The positive and negative terminals of the right piezoelectric ceramic block are connected to the right electrode pin, respectively. The positive and negative terminals of the left piezoelectric ceramic block are connected to the left electrode pin, respectively. The control board applies voltage to the right piezoelectric ceramic block through the right electrode pin, causing the right piezoelectric ceramic block to contract or recover. The control board applies voltage to the left piezoelectric ceramic block through the left electrode pin, causing the left piezoelectric ceramic block to contract or recover. When no voltage is applied, the right and left piezoelectric ceramic blocks are in contact. When voltage is applied, the right and left piezoelectric ceramic blocks form a powder channel. The powder storage tank communicates with the powder channel through the interior of the powder controller housing.

[0009] The aforementioned powder controller also includes a left powder guide block and a right powder guide block; the left powder guide block and the right powder guide block are arranged opposite each other inside the powder controller housing; the left powder guide block and the left piezoelectric ceramic block are arranged sequentially from top to bottom; the right powder guide block and the right piezoelectric ceramic block are arranged sequentially from top to bottom; the structure of the left powder guide block and the structure of the right powder guide block are mirror images of each other; the opposite surfaces of the left powder guide block and the right powder guide block are smooth curved surfaces.

[0010] The opposing surfaces of the left and right guide powder blocks are both smooth curved surfaces composed of at least two non-planar continuous surfaces.

[0011] The aforementioned non-contact powder spreading device for additive manufacturing also includes a pressurizing component, and a top plate is provided on the top of the powder storage tank; the pressurizing component includes an air inlet and an exhaust outlet; the air inlet and the exhaust outlet respectively pass through the top plate and communicate with the interior of the powder storage tank; the non-contact powder spreading device for additive manufacturing also includes a pneumatic butterfly valve that is connected to the powder storage tank and placed on the top plate.

[0012] The aforementioned pressurization component also includes a pressure sensor that extends through the top plate and is placed inside the powder storage tank.

[0013] The aforementioned non-contact powder spreading device for additive manufacturing also includes a powder spreading perforated plate placed at the bottom of the powder controller; the powder spreading perforated plate includes a first powder spreading perforated plate and a second powder spreading perforated plate arranged sequentially from top to bottom; the aperture of the first powder spreading perforated plate and the aperture of the second powder spreading perforated plate are both 0.5mm to 5mm; the powder storage tank is connected to the powder spreading perforated plate through the powder controller.

[0014] The aforementioned non-contact powder spreading device for additive manufacturing also includes a stirring device; the stirring device includes a spiral powder distributor and bearings; there are two sets of bearings; the two sets of bearings are arranged opposite each other on the side wall of the powder storage tank along the axial direction of the powder storage tank; the spiral powder distributor is placed inside the powder storage tank through the bearings; the non-contact powder spreading device for additive manufacturing also includes a mounting base placed outside the powder storage tank and connected to the powder storage tank.

[0015] The lower surface of the aforementioned powder controller is not in contact with the upper surface of the powder bed; preferably, the lower surface of the second powder spreading plate is not in contact with the upper surface of the powder bed; preferably, the distance between the lower surface of the second powder spreading plate and the upper surface of the powder bed is 0.5mm to 1mm.

[0016] The beneficial effects of this invention are:

[0017] This invention provides a non-contact powder spreading device for additive manufacturing, including a powder storage tank, a powder controller, and a control board. The powder controller is placed at the bottom of the powder storage tank. The control board is connected to the powder controller and drives the powder controller to open or close. The lower surface of the powder controller is in non-contact with the upper surface of the powder bed. This device enables non-contact between the powder spreading device and the powder bed, avoiding problems such as tool jamming and powder sticking that are common in existing contact powder spreading devices. It also avoids the low unidirectional efficiency of contact powder spreading, thus improving forming efficiency and forming quality. Simultaneously, this powder spreading device uses piezoelectric ceramics to control powder spreading, enabling precise control of the powder spreading amount and effectively avoiding powder leakage problems that easily occur with conventional powder dispensers. Furthermore, as unsupported forming technology is one of the development trends in additive manufacturing, this non-contact powder spreading device can promote the development of unsupported forming technology. In conclusion, this invention has a promising market prospect and is worth promoting. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the non-contact powder spreading device for additive manufacturing provided by the present invention;

[0019] Figure 2 This is a front cross-sectional view of the non-contact powder spreading device for additive manufacturing provided by the present invention;

[0020] Figure 3 This is a schematic diagram of the powder controller in the open state used in this invention;

[0021] Figure 4 This is a schematic diagram of the powder controller in the off state used in this invention;

[0022] Figure 5 yes Figure 2 A schematic diagram of the structure of a partially enlarged portion (perforated plate);

[0023] In the picture:

[0024] 1-Mounting base; 2-Powder storage tank; 3-Control board; 4-First powder spreading plate; 5-Second powder spreading plate; 6-Powder controller; 601-Powder controller housing; 602-Left powder guide block; 603-Right powder guide block; 604-Right electrode pin; 605-Right piezoelectric ceramic block; 606-Left piezoelectric ceramic block; 607-Left electrode pin; 7-Bearing; 8-Top plate; 9-Spiral powder distributor; 10-Air inlet; 11-Pressure sensor; 12-Exhaust port; 13-Pneumatic butterfly valve. Detailed Implementation

[0025] The following will describe the implementation of the present invention in detail with reference to the embodiments, so as to fully understand how the present invention uses technical means to solve technical problems and achieve technical effects and to implement it accordingly.

[0026] See Figure 1 as well as Figure 2 The present invention provides a non-contact powder spreading device for additive manufacturing, including a powder storage tank 2, a powder controller 6, and a control board 3; the powder controller 6 is placed at the bottom of the powder storage tank 2; the control board 3 is connected to the powder controller 6 and drives the powder controller 6 to open or close; the lower surface of the powder controller 6 is in non-contact with the upper surface of the powder bed.

[0027] Among them, there are one or more powder controllers 6. When there are multiple powder controllers 6, the multiple powder controllers 6 are arranged in parallel along the axial direction of the powder storage tank 2 at the bottom of the powder storage tank 2.

[0028] See Figure 3 The powder controller 6 used in this invention includes a powder controller housing 601, a right electrode pin 604, a right piezoelectric ceramic block 605, a left piezoelectric ceramic block 606, and a left electrode pin 607. The powder controller housing 601 is generally a cylindrical structure with openings at the top and bottom. The right electrode pin 604 and the left electrode pin 607 are arranged opposite each other and placed on the outer wall of the powder controller housing 601. The right piezoelectric ceramic block 605 and the left piezoelectric ceramic block 606 are arranged opposite each other and placed on the inner wall of the powder controller housing 601. The positive and negative electrodes of the right piezoelectric ceramic block 605 are respectively connected to the right electrode pin 604. The positive and negative electrodes of the left piezoelectric ceramic block 606 are respectively connected to the right electrode pin 604. The control board 3 is connected to the left electrode pin 607; the control board 3 applies voltage to the right piezoelectric ceramic block 605 through the right electrode pin 604 and causes the right piezoelectric ceramic block 605 to contract or recover; the control board 3 applies voltage to the left piezoelectric ceramic block 606 through the left electrode pin 607 and causes the left piezoelectric ceramic block 606 to contract or recover; when no voltage is applied, the right piezoelectric ceramic block 605 and the left piezoelectric ceramic block 606 are in contact; when voltage is applied, the right piezoelectric ceramic block 605 and the left piezoelectric ceramic block 606 form a powder channel; the powder storage tank 2 is connected to the powder channel through the inside of the powder controller housing 601.

[0029] The control board 3 applies a voltage of 10-200V to the left piezoelectric ceramic block 606 through the left electrode pin 607; the control board 3 applies a voltage of 10-200V to the right piezoelectric ceramic block 605 through the right electrode pin 604.

[0030] See Figure 3 To facilitate the rapid passage of metal powder in the powder storage tank 2 through the powder controller 6, the powder controller 6 used in this invention further includes a left powder guide block 602 and a right powder guide block 603. The left powder guide block 602 and the right powder guide block 603 are arranged opposite each other inside the powder controller housing 601. The left powder guide block 602 and the left piezoelectric ceramic block 606 are arranged sequentially from top to bottom; the right powder guide block 603 and the right piezoelectric ceramic block 605 are arranged sequentially from top to bottom. The structure of the left powder guide block 602 is a mirror image of the structure of the right powder guide block 603. The opposing surfaces of the left powder guide block 602 and the right powder guide block 603 are smooth curved surfaces. The opposing surfaces of both the left powder guide block 602 and the right powder guide block 603 are smooth curved surfaces composed of at least two non-planar continuous surfaces.

[0031] See Figure 1 as well as Figure 2 The additive manufacturing non-contact powder spreading device also includes a pressurizing component. A top plate 8 is provided on the top of the powder storage tank 2. The pressurizing component includes an air inlet 10 and an exhaust port 12. The air inlet 10 and exhaust port 12 pass through the top plate 8 and communicate with the interior of the powder storage tank 2. The additive manufacturing non-contact powder spreading device also includes a pneumatic butterfly valve 13 connected to the powder storage tank 2 and placed on the top plate 8. Furthermore, the pressurizing component also includes a pressure sensor 11 that passes through the top plate 8 and is placed inside the powder storage tank 2.

[0032] The non-contact powder spreading device for additive manufacturing also includes a powder spreading orifice plate placed at the bottom of the powder controller 6, the structure of which is as follows: Figure 5 As shown. The powder spreading perforated plate includes a first powder spreading perforated plate 4 and a second powder spreading perforated plate 5 arranged sequentially from top to bottom; the aperture of both the first powder spreading perforated plate 4 and the second powder spreading perforated plate 5 is 0.5mm to 5mm; the powder storage tank 2 is connected to the powder spreading perforated plate via a powder controller 6. The lower surface of the bottommost second powder spreading perforated plate 5 is not in contact with the upper surface of the powder bed; preferably, the lower surface of the bottommost second powder spreading perforated plate 5 is 0.5mm to 1mm away from the upper surface of the powder bed.

[0033] See Figure 2 The additive manufacturing non-contact powder spreading device also includes a stirring device; the stirring device includes a spiral powder distributor 9 and bearings 7; there are two sets of bearings 7; the two sets of bearings 7 are arranged opposite each other on the side wall of the powder storage tank 2 along the axial direction of the powder storage tank 2; the spiral powder distributor 9 is placed inside the powder storage tank 2 through the bearings 7; the additive manufacturing non-contact powder spreading device also includes a mounting base 1 placed outside the powder storage tank 2 and connected to the powder storage tank 2. The mounting base 1 is located on both sides of the powder storage tank 2 and is fixed to the powder storage tank 2 by screws, used to fix the entire powder spreading device on the equipment.

[0034] The specific working principle of the non-contact powder spreading device for additive manufacturing provided by this invention is as follows:

[0035] Before applying powder, such as Figure 4 As shown, the powder controller 6 is in the closed state, and the pneumatic butterfly valve 13 is opened under the control of the solenoid valve. The powder delivered externally enters the powder storage tank 2 through the pipe of the pneumatic butterfly valve 13. At the same time, the power source (including but not limited to a motor, existing technology, not described in detail in this invention) drives the spiral powder distributor 9 to rotate through the transmission device (including but not limited to a reducer, coupling, drive shaft, etc.), spreading the powder that has entered the powder storage tank 2 into the entire powder storage tank 2 for temporary storage. After several powder spreading operations, when the powder capacity inside the powder storage tank 2 drops to a certain level, the above operation is repeated to ensure that there is enough powder in the powder storage tank 2 for spreading.

[0036] See Figure 3 During powder spreading, the air inlet 10 is opened and the exhaust port 12 is closed by controlling the solenoid valve. Inert gas (including but not limited to argon and nitrogen) enters the powder storage tank 2, forming a positive pressure of 0.1 MPa to 1.0 MPa inside the powder storage tank 2 (the specific formation process is detailed below) to enhance the downward flowability of the powder. Then, the control board 3 applies voltage to the powder controller 6, applying a voltage of 10V to 200V between the right electrode pin 604 and the left electrode pin 607 on both sides of the powder controller housing 601. Through the internal circuitry, this voltage can be applied to the positive and negative poles of the right piezoelectric ceramic block 605 and the left piezoelectric ceramic block 606. That is, both the right piezoelectric ceramic block 605 and the left piezoelectric ceramic block 606 will be subjected to the applied 10V to 200V voltage. Under the action of the voltage, both the right piezoelectric ceramic block 605 and the left piezoelectric ceramic block 606 will shrink. After shrinkage, as Figure 3 As shown, the deformation of the piezoelectric ceramic causes the powder channel inside the powder controller 6 to open. Under the combined action of positive pressure (0.1 MPa to 1.0 MPa generated by external inert gas) and gravity (the powder's own gravity) inside the powder storage tank 2, the powder enters along the left powder guide block 602 and the right powder guide block 603 and passes through the powder channel formed by the contraction of the right piezoelectric ceramic block 605 and the left piezoelectric ceramic block 606. After passing through the powder channel inside the powder controller 6, the powder falls onto the first powder spreading plate 4 and further passes through the first powder spreading plate 4 and the second powder spreading plate 5 in sequence to reach the powder bed, thus achieving powder spreading. After powder spreading is completed, the air inlet 10 is closed and the exhaust port 12 is opened by controlling the solenoid valve. The positive pressure inside the powder storage tank 2 disappears. At the same time, the voltage applied to the several powder controllers 6 controlled by the control board 3 is disconnected. The shrinkage deformation of the right piezoelectric ceramic block 605 and the left piezoelectric ceramic 606 disappears, returning to their pre-deformation state. The powder channel between the right piezoelectric ceramic block 605 and the left piezoelectric ceramic 606 caused by shrinkage deformation is closed, and the powder stops falling. Figure 4 As shown, the powder cannot fall through the powder controller 6.

[0037] Once one layer of powder is laid, the powder laying device does not need to return. After the current layer is sintered, the next layer of powder can be laid in the opposite direction. By repeating the above process, the powder laying device can move back and forth to complete the powder laying work in the entire part forming process.

Claims

1. A non-contact powder spreading device for additive manufacturing, characterized in that: The additive manufacturing non-contact powder spreading device includes a powder storage tank (2), a powder controller (6), and a control board (3); the powder controller (6) is placed at the bottom of the powder storage tank (2); the control board (3) is connected to the powder controller (6) and drives the powder controller (6) to open or close; the lower surface of the powder controller (6) is not in contact with the upper surface of the powder bed; The powder controller (6) includes a powder controller housing (601), a right electrode pin (604), a right piezoelectric ceramic block (605), a left piezoelectric ceramic block (606), a left electrode pin (607), a left powder guide block (602), and a right powder guide block (603); the powder controller housing (601) is a cylindrical structure with openings at the top and bottom; the right electrode pin (604) and the left electrode pin (607) are arranged opposite to each other and placed on the outer wall of the powder controller housing (601); the right piezoelectric ceramic block (605) and the left piezoelectric ceramic block (606) are arranged opposite to each other and placed on the outer wall of the powder controller housing (601); the right piezoelectric ceramic block (605) and the left piezoelectric ceramic block (606) are arranged opposite to each other and placed on the outer wall of the powder controller housing (601); the right piezoelectric ceramic block (604) and the left piezoelectric ceramic block (607 ...4) and the left piezoelectric ceramic block (6 Ceramic blocks (606) are arranged opposite each other and placed on the inner wall of the powder controller housing (601); the positive and negative poles of the right piezoelectric ceramic block (605) are respectively connected to the right electrode pin (604); the positive and negative poles of the left piezoelectric ceramic block (606) are respectively connected to the left electrode pin (607); the control board (3) applies voltage to the right piezoelectric ceramic block (605) through the right electrode pin (604) and drives the right piezoelectric ceramic block (605) to contract or recover; the control board (3) applies voltage to the left piezoelectric ceramic block (606) through the left electrode pin (607). A voltage is applied to the ceramic block (606), causing the left piezoelectric ceramic block (606) to shrink or recover; when no voltage is applied, the right piezoelectric ceramic block (605) is in contact with the left piezoelectric ceramic block (606); when a voltage is applied, the right piezoelectric ceramic block (605) and the left piezoelectric ceramic block (606) form a powder channel; the powder storage tank (2) is connected to the powder channel through the inside of the powder controller housing (601); the left powder guide block (602) and the right powder guide block (603) are arranged opposite to each other in the powder controller housing. (601) Inside; the left powder guide block (602) and the left piezoelectric ceramic block (606) are arranged sequentially from top to bottom; the right powder guide block (603) and the right piezoelectric ceramic block (605) are arranged sequentially from top to bottom; the structure of the left powder guide block (602) and the structure of the right powder guide block (603) are mirror images of each other; the opposite surfaces of the left powder guide block (602) and the right powder guide block (603) are smooth curved surfaces; the loaded voltage of the left piezoelectric ceramic block (606) and the right piezoelectric ceramic block (605) is 10V~200V.

2. The non-contact powder spreading device for additive manufacturing according to claim 1, characterized in that: The powder controller (6) is one or more. When there are multiple powder controllers (6), the multiple powder controllers (6) are arranged in parallel along the axial direction of the powder storage tank (2) at the bottom of the powder storage tank (2).

3. The non-contact powder spreading device for additive manufacturing according to claim 1, characterized in that: The opposing surfaces of the left powder guide block (602) and the right powder guide block (603) are both smooth curved surfaces composed of at least two non-planar continuous surfaces.

4. The non-contact powder spreading device for additive manufacturing according to any one of claims 1-3, characterized in that: The additive manufacturing non-contact powder spreading device also includes a pressurizing component, and a top plate (8) is provided on the top of the powder storage tank (2); the pressurizing component includes an air inlet (10) and an exhaust port (12); the air inlet (10) and the exhaust port (12) pass through the top plate (8) and communicate with the inside of the powder storage tank (2); the additive manufacturing non-contact powder spreading device also includes a pneumatic butterfly valve (13) that is connected to the powder storage tank (2) and placed on the top plate (8).

5. The non-contact powder spreading device for additive manufacturing according to claim 4, characterized in that: The pressurization component also includes a pressure sensor (11) that extends through the top plate (8) and is placed inside the powder storage tank (2).

6. The non-contact powder spreading device for additive manufacturing according to claim 5, characterized in that: The additive manufacturing non-contact powder spreading device also includes a powder spreading perforated plate placed at the bottom of the powder controller (6); the powder spreading perforated plate includes a first powder spreading perforated plate (4) and a second powder spreading perforated plate (5) arranged sequentially from top to bottom; the aperture of the first powder spreading perforated plate (4) and the aperture of the second powder spreading perforated plate (5) are both 0.5mm~5mm; the powder storage tank (2) is connected to the powder spreading perforated plate through the powder controller (6).

7. The non-contact powder spreading device for additive manufacturing according to claim 6, characterized in that: The additive manufacturing non-contact powder spreading device also includes a stirring device; the stirring device includes a spiral powder spreader (9) and a bearing (7); the bearing (7) is in two sets; the two sets of bearings (7) are arranged opposite each other on the side wall of the powder storage tank (2) along the axial direction of the powder storage tank (2); the spiral powder spreader (9) is placed inside the powder storage tank (2) through the bearing (7); the additive manufacturing non-contact powder spreading device also includes a mounting base (1) placed outside the powder storage tank (2) and connected to the powder storage tank (2).

8. The non-contact powder spreading device for additive manufacturing according to claim 6, characterized in that: The lower surface of the powder controller (6) is not in contact with the upper surface of the powder bed; the distance between the lower surface of the second powder spreading plate (5) and the upper surface of the powder bed is 0.5mm~1mm.

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