Non-contact powder spreading method, non-contact powder spreading device and additive manufacturing equipment for additive manufacturing

Abstract

The present invention belongs to the technical field of additive manufacturing, and specifically relates to a non-contact powder spreading method, a non-contact powder spreading device and an additive manufacturing equipment for additive manufacturing. A non-contact powder spreading method for additive manufacturing, comprising the following steps: 1) placing powder evenly on a first surface to form a powder layer having a second surface, wherein the first surface is the surface of a sintered part, and the second surface is located above the first surface; 2) removing powder above a third surface from the powder layer, wherein the third surface is located below the second surface and above the first surface, and the powder will not come into contact with the generated part during the powder removal process, and the powder on the surface of the deformed part of the part will be removed during the removal process. During the powder spreading process of the present invention, the powder spreading device will not interfere with or collide with the already printed parts, and has the advantages of stabilizing the printing process, improving the printing success rate, and reducing printing support.

Description

Technical Field

[0001] The present invention belongs to the technical field of additive manufacturing, and specifically relates to a non-contact powder spreading method, a non-contact powder spreading device and additive manufacturing equipment for additive manufacturing. Background Art

[0002] The basic process of additive manufacturing is as follows: the powder feeding device delivers a certain amount of powder to the work surface, the powder spreading device spreads a layer of powder material on the upper surface of the formed part in the forming cylinder to form a powder layer, and the post-heating device heats the powder to a set temperature. The programmed energy beam scans the powder layer to melt or denature the powder and bond it to the formed part below; when a layer of cross-section is processed, the workbench drops one layer of thickness, and the powder spreading device spreads a layer of uniform and dense powder on it, and scans a new layer of cross-section. After several layers of scanning are superimposed, the entire prototype manufacturing is completed.

[0003] In the above-mentioned technologies, the powder spreading device generally uses rollers, scrapers, rubber scrapers, brush scrapers, etc. to spread powder. In the additive manufacturing process, parts will be deformed such as warping and curling during the powder spreading process. The existing powder spreading device will come into contact with the warped, curled and other deformed parts during the powder spreading process, causing the powder spreading device to rigidly collide with the deformed parts of the parts, causing the powder spreading device to loosen and be damaged. It is inevitable to shut down for maintenance or replace the powder spreading device, resulting in the inability to complete the printing in one go. Moreover, due to the rigid collision between the powder spreading device and the deformed parts of the parts, the generation of small-angle parts and thin-walled horizontal parts will fail, and it is not suitable for unsupported printing, so it is impossible to print parts with suspended structures. In addition, the existing powder spreading process cannot guarantee that it will not affect the position and stress state of the undenatured powder material, resulting in uneven stress on the powder surface, affecting the sintering quality. Summary of the Invention

[0004] The present invention provides a non-contact powder spreading method, a non-contact powder spreading device and an additive manufacturing device for additive manufacturing, so as to solve the problem that the existing powder spreading device may loosen or be damaged due to rigid collision with the deformed part of the part.

[0005] In order to achieve the above object, the present invention provides a non-contact powder spreading method for additive manufacturing, comprising the following steps:

[0006] 1) placing powder evenly on a first surface to form a powder layer having a second surface, wherein the first surface is a sintered part surface and the second surface is located above the first surface;

[0007] 2) removing powder from the powder layer above a third surface, the third surface being below the second surface and above the first surface, without contacting the generated part during the powder removal process, and removing powder from the surface of the deformed portion of the part.

[0008] Further, the removing includes vacuum suction.

[0009] Furthermore, when the powder is evenly placed on the first surface, the powder falls at a speed perpendicular to the center of the earth and at speeds in other directions of 0-10 mm / s; the powder falls at a height of 0.1-0.5 mm.

[0010] Furthermore, the thickness of the powder layer is 0.08-0.4 mm, the distance between the second surface and the third surface is 0.04-0.36 mm, and the distance between the third surface and the first surface is 0.04 mm.

[0011] Furthermore, the powder layer is smoothed when the powder is removed, and the powder layer does not come into contact with the generated parts during the smoothing process. The smoothing includes smoothing through a strip-shaped convex spine structure.

[0012] The present invention further provides a non-contact powder spreading device for performing the non-contact powder spreading method, comprising:

[0013] a powder feeding mechanism for evenly placing powder on a first surface to form a powder layer having a second surface, wherein the first surface is a sintered part surface and the second surface is located above the first surface;

[0014] A powder removal mechanism removes powder above a third surface from the powder layer, the third surface being located below the second surface and above the first surface. The powder will not come into contact with the generated parts during the removal process, and the powder on the surface of the deformed part of the part will be removed during the removal process; a conveying mechanism, the powder feeding mechanism and the powder removal mechanism are connected to the conveying mechanism, and the conveying mechanism drives the powder feeding mechanism and the powder removal mechanism to move synchronously along the powder spreading direction.

[0015] Furthermore, the powder feeding mechanism includes a mounting frame, a first rotating driving member, a driving roller, a transmission belt, a wear-resistant sharp-angle transmission member, a drop bin and a vibrator;

[0016] The mounting frame is connected to the conveying mechanism, the wear-resistant acute-angle transmission member and the first rotary driving member are fixedly mounted on the mounting frame, and the output end of the first rotary driving member is connected to the driving roller;

[0017] One end of the wear-resistant acute-angle transmission member is in an arc structure, and the other end is in an acute-angle structure; the arc structure is installed in conjunction with the driving roller, and the tip of the acute-angle structure is rounded;

[0018] The transmission belt is wound around the outer surface of the driving roller and the wear-resistant sharp-angle transmission member, and the rotation of the driving roller drives the transmission belt to move on the driving roller and the wear-resistant sharp-angle transmission member; the drop bin is installed on the mounting frame, and the vibrator is fixedly installed on the outer surface of the drop bin;

[0019] The drop bin is located above the conveying surface of the transmission belt and is close to the arc structure. A drop opening is provided on the drop bin. Powder is located in the drop bin and falls from the drop opening onto the conveying surface of the transmission belt. After being conveyed by the transmission belt, the powder falls from the acute angle structure of the wear-resistant acute angle transmission member onto the first surface.

[0020] The conveying speed of the conveying mechanism is consistent with the transmission speed of the transmission belt.

[0021] Furthermore, the angle of the acute-angle structure is 30°, the thickness of the transmission belt is 1.5-2mm, and the turning radius of the transmission belt at the acute-angle structure is 1-1.5mm; at the acute-angle structure, the distance between the lowest point of the transmission belt and the first surface is 0.1-0.5mm.

[0022] Furthermore, the powder removal mechanism includes a second rotary drive member, a vacuum roller, an inner cylinder, and a negative pressure generator; the second rotary drive member is mounted on the mounting frame, and the output end of the second rotary drive member is connected to the vacuum roller; the inner cylinder is located within the vacuum roller, the inner cylinder is connected to the negative pressure generator, a negative pressure is formed within the inner cylinder, and the inner cylinder is fixedly connected to the mounting frame; the inner cylinder is provided with a slit structure along its length, and the vacuum roller is evenly distributed with a plurality of micropores;

[0023] When the second rotary driving member drives the vacuum roller to rotate, the powder above the third surface is sucked from the powder layer into the inner cylinder under the negative pressure of the inner cylinder.

[0024] Furthermore, the micropores on the surface of the vacuum roller are formed into a plurality of micropore strips arranged side by side at equal intervals, and each micropore strip is composed of a plurality of micropores arranged side by side at equal intervals; the shape of the micropores is circular, oval, or diamond with rounded corners;

[0025] The microporous strips are parallel to the rotation center line of the inner cylinder, or the microporous strips are at an angle between -45° and 45° to the rotation center line of the inner cylinder.

[0026] Furthermore, the slit structure is located at the lowest point of the inner cylinder;

[0027] Alternatively, the slit structure is located on the left or right side of the lowest point of the inner cylinder, and the angle between the slit structure and the perpendicular bisector of the inner cylinder is between -30° and +30°;

[0028] The width of the slit structure is 0.03-6 mm.

[0029] Furthermore, the outer surface of the vacuum roller is provided with a plurality of convex thorn structures, and the convex thorn structures and the microporous strips are arranged in parallel and alternately; the height of the convex thorn structures is 0.03-6 mm; when the powder removal mechanism (20) removes powder, the convex thorn structures (211) smooth the powder layer, and the convex thorn structures (211) will not contact the generated parts.

[0030] The present invention also provides an additive manufacturing device, characterized in that it includes the non-contact powder spreading device, and also includes a residual powder recovery mechanism and a powder feeding box, the powder feeding box sends the powder into the drop bin; the residual powder recovery mechanism is connected to the inner cylinder, and the powder in the inner cylinder is recovered into the residual powder recovery mechanism.

[0031] The beneficial effects of the present invention are as follows:

[0032] 1. The powder of the present invention is evenly placed on the first surface to ensure the density of the powder layer, and the second surface can fully or mostly cover the defects such as warping and depression on the surface of the sintered parts. The powder above the third surface on the rear powder layer is removed, and the remaining powder layer between the third surface and the first surface is used for printing. In the present invention, the powder will not come into contact with the generated parts when it is removed, and there will be no problem of rigid collision during the powder spreading process, so that the powder spreading device will not become loose or damaged, effectively improving the stability and success rate of printing or achieving one-time printing. Since there will be no rigid collision during the powder spreading process, small-angle parts and thin-walled horizontal parts can be printed, reducing printing support or being suitable for support-free printing, realizing the printing of parts with suspended structures, and having a wider range of applications.

[0033] 2. When the present invention removes the powder above the third surface, the powder on the surface of the deformed part of the part is removed. Therefore, the deformed part can be scanned or not during the energy beam scanning process, that is, the deformed part of the part can be sintered or not. In this way, after multiple layers of sintering, the deformed part is eliminated, which can reduce or eliminate defects that occur during the printing process.

[0034] 3. The powder of the present invention has velocity only in the direction of gravity when falling, with zero or very low velocity in other directions. Furthermore, the height of the falling powder is very close to the first surface, so the kinetic energy of the falling powder when it reaches the first surface is very low, which has little or no impact on the state of the powder or parts already on the first surface. This also avoids the problem of ripples on the powder surface caused by falling too high, resulting in uneven force on the powder surface and affecting sintering quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0036] Figure 1 A schematic diagram of the structure of an embodiment of the present invention Figure 1 , at this time, the slit structure is located on the left side of the lowest point of the inner cylinder;

[0037] Figure 2 A schematic diagram of the structure of an embodiment of the present invention Figure 2 ;

[0038] Figure 3 is a three-dimensional schematic diagram of an embodiment of the present invention;

[0039] Figure 4 This is a partial schematic diagram of the powder removal mechanism of the present invention, where the slit mechanism is located at the lowest point of the inner cylinder;

[0040] Figure 5 This is a partial schematic diagram of the powder removal mechanism of the present invention, in which the slit mechanism is located on the right side of the lowest point of the inner cylinder;

[0041] Figure 6 The structure of the vacuum roller in the embodiment of the present invention is shown as follows: Figure 1 ;

[0042] Figure 7 The structure of the vacuum roller in the embodiment of the present invention is shown as follows: Figure 2 ;

[0043] Figure 8 The structure of the vacuum roller in the embodiment of the present invention is shown as follows: Figure 3 ;

[0044] Figure 9 The structure of the vacuum roller in the embodiment of the present invention is shown as follows: Figure 4 ;

[0045] Figure 10 The structure of the vacuum roller in the embodiment of the present invention is shown as follows: Figure 5 ;

[0046] Figure 11 The structure of the vacuum roller in the embodiment of the present invention is shown as follows: Figure 6 .

[0047] The above reference numerals:

[0048] 101 first surface, 102 second surface, 103 third surface, 10 powder feeding mechanism, 11 feeding bin, 12 vibrator, 13 transmission belt, 14 driving roller, 15 wear-resistant sharp-angle transmission member, 16 first rotary driving member, 17 mounting frame, 20 powder removal mechanism, 21 vacuum roller, 210 micropores, 211 convex thorn structure, 22 inner cylinder, 220 slit structure, 23 second rotary driving member. DETAILED DESCRIPTION

[0049] To facilitate understanding of the present invention, the present invention will be described more fully below with reference to the accompanying drawings. Preferred embodiments of the present invention are shown in the accompanying drawings. However, the present invention may be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and comprehensive understanding of the present disclosure.

[0050] Example 1

[0051] like Figure 1 As shown, this embodiment provides a non-contact powder spreading method for additive manufacturing, comprising the following steps:

[0052] 1) Powder is evenly placed on a first surface 101 to form a powder layer having a second surface 102 , wherein the first surface 101 is the surface of the sintered part, and the second surface 102 is located above the first surface 101 ;

[0053] 2) removing powder above the third surface 103 from the powder layer, wherein the third surface 103 is located below the second surface 102 and above the first surface 101, without contacting the generated part during the powder removal process, and removing powder from the surface of the deformed part of the part; wherein the removal may include vacuum suction, and of course other removal methods may also be used, as long as the functional requirements of this embodiment are met.

[0054] In this embodiment, the powder is evenly placed on the first surface 101 to ensure the density of the powder layer, and the second surface 102 can fully or mostly cover the warping, depression and other defects on the surface of the sintered parts. The powder above the third surface 103 on the rear powder layer is removed, and the remaining powder layer between the third surface 103 and the first surface 101 is used for printing. In this embodiment, the powder will not come into contact with the generated parts when it is removed, and there will be no problem of rigid collision during the powder spreading process, so that the powder spreading device will not become loose or damaged, effectively improving the stability and success rate of printing or achieving one-time printing. Since there will be no rigid collision during the powder spreading process, small-angle parts and thin-walled horizontal parts can be printed, reducing printing support or being suitable for support-free printing, realizing the printing of parts with suspended structures, and having a wider range of applications.

[0055] In this embodiment, when the powder above the third surface 103 is removed, the powder on the surface of the deformed part of the part is removed. Therefore, the deformed part can be scanned or not scanned during the energy beam scanning process, that is, the deformed part can be sintered or not. In this way, after multiple layers of sintering, the deformed part is eliminated, which can reduce or eliminate defects that occur during the printing process.

[0056] In this embodiment, when the powder is evenly placed on the first surface 101, the powder falls at a speed perpendicular to the center of the earth, and the speed in other directions is between 0-10 mm / s; the height to which the powder falls is 0.1-0.5 mm. Therefore, when the powder falls, it has speed only in the direction of gravity, and the speed in other directions is zero or extremely small. Moreover, the height to which the powder falls is very close to the first surface 101, so that the kinetic energy of the falling powder when it reaches the first surface 101 is very low, having little or no impact on the state of the powder or parts already on the first surface 101, and avoiding the problem of the powder falling too high causing ripples on the powder surface, resulting in uneven force on the powder surface and affecting the sintering quality.

[0057] In this embodiment, preferably, the thickness of the powder layer is 0.08-0.4 mm, the distance between the second surface 102 and the third surface 103 is 0.04-0.36 mm, and the distance between the third surface 103 and the first surface 101 is 0.04 mm. For example, when the thickness of the powder layer is 0.36 mm, the distance between the second surface 102 and the third surface 103 is 0.32 mm, i.e., the thickness of the removed powder is 0.32 mm; when the thickness of the powder layer is 0.2 mm, the distance between the second surface 102 and the third surface 103 is 0.16 mm, i.e., the thickness of the removed powder is 0.16 mm, and so on.

[0058] Furthermore, in this embodiment, to ensure the density and smoothness of the powder after removal, the powder layer is smoothed during removal. This smoothing process prevents contact with the finished part. This smoothing is performed using strip-shaped ridge structures 211. Of course, other smoothing methods can also be used as long as they meet the functional requirements of this embodiment. Since the smoothing process prevents contact with the finished part, there is no problem of rigid impact during powder smoothing.

[0059] Example 2

[0060] like Figure 1-11 As shown, this embodiment provides a non-contact powder spreading device for executing the non-contact powder spreading method described in Example 1, comprising:

[0061] The powder feeding mechanism 10 evenly places powder on a first surface 101 to form a powder layer having a second surface 102 . The first surface 101 is a sintered part surface, and the second surface 102 is located above the first surface 101 .

[0062] The powder removal mechanism 20 removes powder above the third surface 103 from the powder layer, where the third surface 103 is located below the second surface 102 and above the first surface 101. The powder removal process does not contact the generated parts, and the powder on the surface of the deformed part is removed during the removal process; the removal includes vacuum suction.

[0063] The conveying mechanism (not shown in the figure) is connected to the powder feeding mechanism 10 and the powder removing mechanism 20. The conveying mechanism drives the powder feeding mechanism 10 and the powder removing mechanism 20 to move synchronously along the powder spreading direction.

[0064] In this embodiment, the powder is evenly placed on the first surface 101 by the powder feeding mechanism 10, and then the excess powder is removed by the powder removal mechanism 20, and the powder will not come into contact with the generated parts during the removal process. At the same time, the powder feeding mechanism 10 and the powder removal mechanism 20 are synchronously installed on the conveying mechanism, so that the powder can be fed and removed at the same time, thereby improving the powder spreading efficiency. Therefore, in this embodiment, there is no problem of rigid collision during the powder spreading process, so that the powder spreading device will not become loose or damaged, effectively improving the stability and success rate of printing or achieving one-time printing. Since there will be no rigid collision during the powder spreading process, small-angle parts and thin-walled horizontal parts can be printed, reducing printing support or being suitable for support-free printing, realizing the printing of parts with suspended structures, and having a wider range of applications.

[0065] In this embodiment, the conveying mechanism is an existing horizontal conveying mechanism. The structural forms of the horizontal conveying mechanism are various, such as a structure in which a motor cooperates with a gear rack, or a structure in which a motor cooperates with a belt pulley, etc. At the same time, it is combined with a guide mechanism such as a guide rail and guide groove structure to guide the horizontal movement. This is an existing conventional technology and is not the focus of this embodiment, so it will not be elaborated on.

[0066] This embodiment is further preferred, the powder feeding mechanism 10 includes a mounting frame 17, a first rotating drive member 16, a driving roller 14, a transmission belt 13, a wear-resistant sharp-angle transmission member 15, a drop bin 11 and a vibrator 12; the mounting frame 17 is connected to the conveying mechanism, the wear-resistant sharp-angle transmission member 15 and the first rotating drive member 16 are fixedly mounted on the mounting frame 17, and the output end of the first rotating drive member 16 is connected to the driving roller 14.

[0067] One end of the wear-resistant acute-angle transmission member 15 is an arc structure, and the other end is an acute-angle structure; the arc structure is installed in cooperation with the driving roller 14, and the tip of the acute-angle structure is rounded; the transmission belt 13 is wound around the outer surface of the driving roller 14 and the wear-resistant acute-angle transmission member 15, and the rotation of the driving roller 14 drives the transmission belt 13 to move on the driving roller 14 and the wear-resistant acute-angle transmission member 15; the blanking bin 11 is installed on the mounting frame 17, and the vibrator 12 is fixedly installed on the outer surface of the blanking bin 11.

[0068] The dropping bin 11 is located above the conveying surface of the transmission belt 13, and the dropping bin 11 is close to the arc structure; a dropping port is provided on the dropping bin 11; the powder is located in the dropping bin 11 and falls from the dropping port onto the conveying surface of the transmission belt 13, and after being conveyed by the transmission belt 13, falls from the acute angle structure of the wear-resistant acute angle transmission member 15 to the first surface 101; the conveying speed of the conveying mechanism is consistent with the transmission speed of the transmission belt 13.

[0069] When the powder feeding mechanism 10 of this embodiment is working, the powder is located in the drop bin 11, and the vibrator 12 realizes the vibration of the drop bin 11 and transmits the vibration to the powder in the drop bin 11, so that the powder can be evenly and quickly transferred from the drop port to the conveyor belt 13. After being pre-laid and conveyed by the conveyor belt 13, the powder falls from the acute angle structure of the conveyor belt 13 onto the first surface 101, and the conveying speed of the conveying mechanism is consistent with the transmission speed of the transmission belt 13, so that the powder can fall evenly on the first surface 101, ensuring the density of the powder.

[0070] The design of the wear-resistant sharp-angle transmission member 15 and its sharp-angle structure enables the transmission belt 13 to be wound around the outer surface of the driving roller 14 and the wear-resistant sharp-angle transmission member 15, so that the blanking end of the transmission belt 13 can be effectively close to the first surface 101, thereby reducing the height of the falling powder, so that the powder has speed only in the direction of gravity when falling, and the speed in other directions is zero or extremely small. In this way, the kinetic energy of the falling powder when reaching the first surface 101 is very low, which has little or no impact on the state of the existing powder or parts on the first surface 101, and avoids the problem of ripples on the powder surface caused by too high a powder falling, resulting in uneven force on the powder surface and affecting the sintering quality.

[0071] Preferably, in this embodiment, the angle of the acute-angle structure is 30°, the thickness of the transmission belt 13 is 1.5-2 mm, and the turning radius of the transmission belt 13 at the acute-angle structure is 1-1.5 mm, wherein the turning design at the acute-angle structure can ensure that the distance between the transmission belt 13 and the first surface 101 is closer; at the acute-angle structure, the distance between the lowest point of the transmission belt 13 and the first surface 101 is 0.1-0.5 mm, and this distance ensures that the hovering time of the falling powder is short, so that the kinetic energy of the falling powder is very low when it reaches the first surface 101.

[0072] In this embodiment, preferably, the first rotary drive member 16 directly adopts a motor. Of course, a structure in which a motor and a reducer are matched can also be adopted. This is an existing mature technology and will not be elaborated in detail here.

[0073] In this embodiment, preferably, the material of the wear-resistant sharp-angle transmission member 15 is polytetrafluoroethylene, nylon, ultra-high molecular weight polyethylene fiber, polyetheretherketone, polyvinyl chloride, copper alloy, stainless steel, titanium alloy, etc.

[0074] This embodiment is further preferred, the powder removal mechanism 20 includes a second rotary drive member 23, a vacuum roller 21, an inner cylinder 22 and a negative pressure generator (not shown in the figure); the second rotary drive member 23 is mounted on the mounting frame 17, and the output end of the second rotary drive member 23 is connected to the vacuum roller 21, the inner cylinder 22 is located in the vacuum roller 21, the inner cylinder 22 is connected to the negative pressure generator, negative pressure is formed in the inner cylinder 22, and the inner cylinder 22 is fixedly connected to the mounting frame 17, the inner cylinder 22 is provided with a slit structure 220 along its length direction, and a number of micropores 210 are evenly distributed on the vacuum roller 21; when the second rotary drive member 23 drives the vacuum roller 21 to rotate, under the action of the negative pressure of the inner cylinder 22, the powder above the third surface 103 is sucked from the powder layer into the inner cylinder 22.

[0075] When the powder removal mechanism 20 of this embodiment is in operation, the negative pressure generator creates a negative pressure within the inner cylinder 22, and the second rotary drive member 23 drives the vacuum roller 21 to rotate. As the conveying mechanism drives the powder removal mechanism 20, the negative pressure in the inner cylinder 22 causes the powder to enter the inner cylinder 22 through the micropores 210 in the vacuum roller 21 and the slit structure 220 in the inner cylinder 22, completing the powder removal process. During the removal process, the powder removed does not affect the smoothness of the powder.

[0076] In this embodiment, preferably, the second rotary drive member 23 can directly adopt a motor. Of course, it can also adopt a structural form in which an electric motor and a reduction mechanism are matched. This is an existing mature technology and will not be elaborated in detail.

[0077] In this embodiment, preferably, the negative pressure generator can adopt existing mature products such as existing vacuum chambers, negative pressure fans, and vacuum cleaners, and no specific limitation is made thereto.

[0078] See also Figure 1 and 2 As shown, the direction of the arrow pointing to the right is the conveying direction of the conveying mechanism, that is, the powder spreading direction, and the vacuum roller 21 and the transmission belt 13 both rotate counterclockwise. This is one embodiment. Of course, the conveying direction of the conveying mechanism can be to the left, and the vacuum roller 21 and the transmission belt 13 can also rotate clockwise. This is not limited.

[0079] In this embodiment, preferably, the micropores 210 on the surface of the vacuum roller 21 are formed into a plurality of micropore strips arranged side by side at equal intervals, and each micropore strip is composed of a plurality of micropores 210 arranged side by side at equal intervals; the shape of the micropores 210 is circular (see Figure 6 As shown), waisted (see Figure 7 、 9 -11) or a diamond with rounded corners (see Figure 8 Of course, other structural forms can also be used, and this is not specifically limited.

[0080] The microporous strip is parallel to the rotation center line of the inner cylinder 22 (see Figure 6-8 , 10), or the microporous strip and the rotation center line of the inner cylinder 22 are at an angle between -45° and 45° (see Figure 9 and 11 shown).

[0081] In this embodiment, the slit structure 220 is preferably located at the lowest point of the inner cylinder 22 (see Figure 4 As shown), the inner cylinder 22 sucks away the powder from just above the second surface 102.

[0082] Alternatively, the slit structure 220 is located on the left side of the lowest point of the inner cylinder 22 (see Figure 1and 2 shown) or on the right (see Figure 5 As shown), and the angle between the slit structure 220 and the perpendicular bisector of the inner cylinder 22 is between -30° and +30° (as shown Figure 1 、 2 , 5); so that the inner cylinder 22 sucks away the powder from the side of the second surface 102 rather than directly above it, which can more stably remove the powder.

[0083] In this embodiment, the width of the slit structure 220 is 0.03-6 mm, preferably 0.08 mm, 1 mm, 2 mm, 4 mm, 5 mm, etc., and the specific value depends on the actual situation.

[0084] In this embodiment, the outer surface of the vacuum roller 21 is further provided with a plurality of convex ridge structures 211 (see Figure 2 、 10 and 11), the convex thorn structure 211 and the microporous strips are arranged in parallel and alternately; the height of the convex thorn structure 211 is 0.03-6mm, and can be preferably 0.08mm, 1mm, 2mm, 4mm, 5mm, etc. When the powder removal mechanism 20 removes the powder, the convex thorn structure 211 smoothes the powder layer, and the convex thorn structure 211 does not come into contact with the generated parts. The design of the convex thorn structure 211 allows the convex thorn structure 211 to smooth the surface of the powder before sucking away the powder when the powder is removed. The convex thorn structure 211 not only smoothes the powder surface, but also improves the density of the powder and improves the sintering quality. Moreover, no rigid impact occurs during smoothing.

[0085] Example 3

[0086] The present embodiment provides an additive manufacturing device, comprising the non-contact powder spreading device described in Example 2, and further comprising a residual powder recovery mechanism and a powder delivery box, wherein the powder delivery box delivers the powder to the blanking bin 11; the residual powder recovery mechanism is connected to the inner cylinder 22, and the powder in the inner cylinder 22 is recovered to the residual powder recovery mechanism. The powder is delivered to the blanking bin 11 by the powder delivery box, and the powder sucked into the inner cylinder 22 is recovered to the residual powder recovery mechanism, thereby realizing the recycling of powder and saving resources. The residual powder recovery mechanism is a conventional component of existing additive manufacturing equipment, and the existing structure can be directly adopted, so no further explanation will be given.

[0087] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A non-contact powder spreading device, characterized in that: include: A powder feeding mechanism (10) is configured to uniformly place powder on a first surface (101) to form a powder layer having a second surface (102), wherein the first surface (101) is a sintered part surface, and the second surface (102) is located above the first surface (101); a powder removal mechanism (20) for removing powder above a third surface (103) from the powder layer, wherein the third surface (103) is located below the second surface (102) and above the first surface (101), wherein the powder removal mechanism does not contact the formed part during the powder removal process, and removes powder on the surface of the deformed part during the removal process; A conveying mechanism, wherein the powder feeding mechanism (10) and the powder removing mechanism (20) are connected to the conveying mechanism, and the conveying mechanism drives the powder feeding mechanism (10) and the powder removing mechanism (20) to move synchronously along the powder spreading direction; The powder feeding mechanism (10) comprises a mounting frame (17), a first rotating driving member (16), a driving roller (14), a transmission belt (13), a wear-resistant sharp-angle transmission member (15), a drop bin (11) and a vibrator (12); The mounting frame (17) is connected to the conveying mechanism, the wear-resistant acute-angle transmission member (15) and the first rotary driving member (16) are fixedly mounted on the mounting frame (17), and the output end of the first rotary driving member (16) is connected to the driving roller (14); One end of the wear-resistant acute-angle transmission member (15) is in an arc structure, and the other end is in an acute-angle structure; the arc structure is installed in conjunction with the driving roller (14), and the tip of the acute-angle structure is rounded; The transmission belt (13) is wound around the outer surface of the driving roller (14) and the wear-resistant acute-angle transmission member (15), and the driving roller (14) rotates to drive the transmission belt (13) to move on the driving roller (14) and the wear-resistant acute-angle transmission member (15); the blanking bin (11) is installed on the mounting frame (17), and the vibrator (12) is fixedly installed on the outer surface of the blanking bin (11); The drop bin (11) is located above the conveying surface of the transmission belt (13), and the drop bin (11) is close to the arc structure; a drop opening is provided on the drop bin (11); powder is located in the drop bin (11) and drops from the drop opening onto the conveying surface of the transmission belt (13), and after being conveyed by the transmission belt (13), drops from the acute angle structure of the wear-resistant acute angle transmission member (15) onto the first surface (101); The conveying speed of the conveying mechanism is consistent with the transmission speed of the transmission belt (13).

2. The non-contact powder spreading device according to claim 1, characterized in that: The angle of the acute angle structure is 30°, the thickness of the transmission belt (13) is 1.5-2 mm, and the turning radius of the transmission belt (13) at the acute angle structure is 1-1.5 mm; at the acute angle structure, the distance between the lowest point of the transmission belt (13) and the first surface (101) is 0.1-0.5 mm.

3. The non-contact powder spreading device according to claim 1, characterized in that: The powder removal mechanism (20) comprises a second rotary drive member (23), a vacuum roller (21), an inner cylinder (22) and a negative pressure generator; the second rotary drive member (23) is mounted on the mounting frame (17), and the output end of the second rotary drive member (23) is connected to the vacuum roller (21); the inner cylinder (22) is located inside the vacuum roller (21); the inner cylinder (22) is connected to the negative pressure generator; a negative pressure is formed inside the inner cylinder (22); the inner cylinder (22) is fixedly connected to the mounting frame (17); a slit structure (220) is provided along its length direction; and a plurality of micropores (210) are evenly distributed on the vacuum roller (21); When the second rotary drive member (23) drives the vacuum roller (21) to rotate, the powder above the third surface (103) is sucked from the powder layer into the inner cylinder (22) under the negative pressure of the inner cylinder (22).

4. The non-contact powder spreading device according to claim 3, characterized in that: The micropores (210) on the surface of the vacuum roller (21) are formed into a plurality of micropore strips arranged side by side at equal intervals, and each micropore strip is composed of a plurality of micropores (210) arranged side by side at equal intervals; the shape of the micropores (210) is circular, oval, or diamond with rounded corners; The microporous strip is parallel to the rotation center line of the inner cylinder (22), or the microporous strip is at an angle between -45° and 45° to the rotation center line of the inner cylinder (22).

5. The non-contact powder spreading device according to claim 4, characterized in that: The slit structure (220) is located at the lowest point of the inner cylinder (22); Alternatively, the slit structure (220) is located on the left or right side of the lowest point of the inner cylinder (22), and the angle between the slit structure (220) and the perpendicular bisector of the inner cylinder (22) is between -30° and +30°; The width of the slit structure (220) is 0.03-6 mm; The outer surface of the vacuum roller (21) is further provided with a plurality of convex thorn structures (211), and the convex thorn structures (211) and the microporous strips are arranged alternately and in parallel; the height of the convex thorn structures (211) is 0.03-6 mm; when the powder removal mechanism (20) removes powder, the convex thorn structures (211) smooth the powder layer, and the convex thorn structures (211) will not contact the generated parts.

6. An additive manufacturing device, characterized in that: It includes the non-contact powder spreading device according to any one of claims 1 to 5, and also includes a residual powder recovery mechanism and a powder delivery box, the powder delivery box delivers the powder to the drop bin (11); the residual powder recovery mechanism is connected to the inner cylinder (22), and the powder in the inner cylinder (22) is recovered into the residual powder recovery mechanism.

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