Scraper and powder spreading device

Abstract

The utility model discloses a scraper and a powder spreading device, relates to the technical field of 3D printing, and aims to solve the problem of poor powder spreading uniformity during manufacturing. The scraper comprises a fixing part and a scraper body which are connected, a first scraper, a second scraper and a third scraper which are sequentially arranged at intervals in the scraping direction are arranged at the end, away from the fixing part, of the scraper body, the length of the first scraper is smaller than that of the second scraper, the first scraper is provided with a first inclined face, and the sectional area of the first scraper is gradually decreased downwards in the vertical direction. A plurality of comb teeth used for filtering powder are distributed on the second scraper at intervals in the direction perpendicular to the scraping direction, and the end, away from the fixing part, of the third scraper and the end, away from the fixing part, of the second scraper are located in the same horizontal plane. And the fixed part is moved in the scraping and conveying direction to drive the scraper body to move, so that the powder is scraped and conveyed by the first inclined surface, the powder is filtered by the comb teeth on the second scraper, and finally, the surface of the screened powder is flattened by the third scraper, so that the powder paving uniformity is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of 3D printing, in particular to a scraper and a powder spreading device. Background Art

[0002] 3D printing is widely used in the aerospace field and the manufacture of metal devices with load shapes. SLM technology is an important processing technology for laser 3D printing. It realizes the forming of parts by controlling the high-energy-density laser beam, constructing the 3D model using 3D modeling software, importing the model into Magics software for slicing, pre-planning a reasonable scanning path, and setting reasonable laser parameters. This is the pre-processing stage of comb control. The powder of the processing preparation material is added to the powder supply platform, and the laser beam moves and scans in a single layer. The material melts and solidifies to achieve a strong metallurgical bond. After the laser scanning is completed, it returns to its original position, completing a layer-by-layer cycle, and finally forming a solid part through successive cycles.

[0003] At present, when using selective laser melting (SLM) for preparation, large particles in the powder will cause printing defects, and uneven powder spreading will cause large missing parts on the surface of the part. In addition, uneven spreading of metal powder may cause uneven heating, resulting in warping and other phenomena. As a result, the durability of the powder spreading device of the SLM equipment is low and it needs to be replaced more frequently. Utility Model Content

[0004] The utility model aims to provide a scraper and a powder spreading device, which are used to improve the uniformity of powder spreading.

[0005] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0006] In a first aspect, the utility model provides a scraper, comprising:

[0007] Fixed part;

[0008] The scraper body is connected to the fixed part. The end of the scraper body away from the fixed part is provided with a first scraper, a second scraper and a third scraper arranged in sequence in the scraping direction. The extension length of the first scraper relative to the fixed part is less than the extension length of the second scraper relative to the fixed part. The first scraper has a first inclined surface on a side away from the second scraper. The cross-sectional area of ​​the first scraper gradually decreases along the extension direction away from the fixed part. The second scraper has a plurality of comb teeth spaced apart in a direction perpendicular to the scraping direction. The plurality of comb teeth are used to filter large particles of powder. The third scraper and the end away from the fixed part and the end of the second scraper away from the fixed part are in the same horizontal plane.

[0009] Optionally, in the above scraper, the connecting portion is connected to the fixing portion, and a first clamping groove is provided on a side of the connecting portion away from the fixing portion, and the first clamping groove is used for clamping with the scraper body.

[0010] Optionally, in the above-mentioned scraper, the blade tooth thickness of the third scraper at one end away from the fixing portion is greater than both the blade tooth thickness of the first scraper and the blade tooth thickness of the second scraper.

[0011] Optionally, in the above-mentioned scraper, a second inclined surface is provided on a side of the third scraper close to the second scraper, and an angle θ exists between the inclination direction of the second inclined surface relative to the horizontal plane and the scraping direction, satisfying 45°≤θ≤90°.

[0012] Optionally, in the above-mentioned scraper, a second slot is provided on a side of the third scraper away from the second scraper, and the scraper also includes a rubber rod, which is clamped with the third scraper through the second slot, and the bottom end of the rubber rod and the end of the third scraper away from the fixed part are in the same horizontal plane.

[0013] Optionally, the scraper further includes a fourth scraper, which is located between the second scraper and the third scraper, and one end of the fourth scraper away from the fixed portion and one end of the third scraper away from the fixed portion are in the same horizontal plane.

[0014] Optionally, in the above-mentioned scrapers, the tooth thickness of the fourth scraper is greater than or equal to the tooth thickness of the second scraper.

[0015] Optionally, in the above-mentioned scrapers, a bottom edge of the fourth scraper on a side close to the second scraper is rounded.

[0016] Optionally, in the above scraper, the comb teeth include: a first rack and a second rack, the length of the first rack is smaller than the length of the second rack, and the first rack and the second rack are alternately arranged in the same horizontal plane along a direction perpendicular to the scraping direction.

[0017] In the second aspect, the utility model also provides a powder spreading device, including a driving component, a powder supply platform, a molding platform and any one of the scrapers above, the driving end of the driving component is connected to the fixed part, the driving component is used to drive the fixed part to drive the scraper body to move together and pass through the powder supply platform and the molding platform in sequence.

[0018] Compared with the prior art, when the above technical solution is adopted, during operation, after the operator installs the scraper body and the fixed part, the fixed part is moved along the scraping direction to drive the scraper body to move. During this process, the first inclined surface on the first scraper contacts the powder and scrapes it. After the powder is scraped to the second scraper, it is filtered through multiple comb teeth to isolate the large particles of powder on the side of the comb teeth close to the first scraper. After screening, the powder that meets the requirements can finally contact the third scraper through the comb teeth. During the movement, the third scraper gradually flattens and compacts the surface of the powder; after one powder spreading is completed, the operator moves the scraper body and the fixed part to the initial position, repeats the above operation, and continues to complete the powder spreading work. Compared with the traditional scraper, the present application only needs to move the scraper body so that the first scraper, the second scraper and the third scraper can successively scrape, screen and spread the powder during the scraping process, so as to complete the screening of large particles in the powder during the printing process, avoid the influence of the generated large particles on the printing effect, and improve the uniformity of powder spreading. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention. In the drawings:

[0020] Figure 1 This is a schematic diagram of the overall structure of a scraper in an embodiment of the utility model;

[0021] Figure 2 This is a schematic structural diagram of a fixing portion of a scraper in an embodiment of the utility model;

[0022] Figure 3 This is a structural schematic diagram of a connection portion of a scraper in an embodiment of the utility model;

[0023] Figure 4 It is a structural schematic diagram of a scraper body of a scraper in an embodiment of the utility model;

[0024] Figure 5 for Figure 4 Left view of;

[0025] Figure 6 for Figure 4 A partial enlarged view of

[0026] Figure 7 It is a structural schematic diagram of a rubber rod of a scraper in an embodiment of the utility model.

[0027] Reference numerals:

[0028] 1-fixing part; 11-weight-reducing hole; 2-scraper body; 21-first scraper; 211-first inclined surface; 22-second scraper; 221-comb teeth; 23-third scraper; 231-second inclined surface; 232-rubber rod; 233-second slot; 24-fourth scraper; 3-connecting part; 31-first slot; 32-through hole. DETAILED DESCRIPTION

[0029] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0030] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0031] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present utility model, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined. The meaning of "several" is one or more, unless otherwise clearly and specifically defined.

[0032] In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0033] In the description of the present utility model, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0034] like Figure 1-Figure 7As shown, a scraper provided by an embodiment of the utility model includes: a fixing portion 1 and a scraper body 2.

[0035] Among them, the scraper body 2 is connected to the fixed part 1, and the end of the scraper body 2 away from the fixed part 1 is provided with a first scraper 21, a second scraper 22 and a third scraper 23 arranged at intervals along the scraping direction. The extension length of the first scraper 21 relative to the fixed part 1 is less than the extension length of the second scraper 22 relative to the fixed part 1. The first scraper 21 has a first inclined surface 211 on a side away from the second scraper 22. The cross-sectional area of ​​the first scraper 21 gradually decreases downward in the vertical direction. The first inclined surface 211 is used for scraping powder. The second scraper 22 has a plurality of comb teeth 221 spaced apart in a direction perpendicular to the scraping direction. The plurality of comb teeth 221 are used to filter metal powder. The end of the third scraper 23 away from the fixed part 1 and the end of the second scraper 22 away from the fixed part 1 are in the same horizontal plane.

[0036] When implementing it, Figure 1 As shown, during operation, after the operator installs the scraper body 2 and the fixing part 1, the fixing part 1 is moved along the scraping direction (i.e., the direction indicated by arrow A) to drive the scraper body 2 to move. During this process, the first inclined surface 211 on the first scraper 21 contacts the powder and scrapes it. After the powder is scraped to the second scraper 22, it is filtered by a plurality of comb teeth 221, and the large particles of powder are isolated on the side of the comb teeth 221 close to the first scraper 21. The powder that meets the requirements after screening can pass through the comb teeth 221 and finally contact the third scraper 23. During the movement The third scraper 23 gradually levels and compacts the powder surface; after one powder spreading is completed, the operator moves the scraper body 2 and the fixed part 1 to the initial position, repeats the above operation, and continues to complete the powder spreading work. Compared with the traditional scraper, the present application only needs to move the scraper body so that the first scraper 21, the second scraper 22 and the third scraper 23 can scrape, screen and level the powder in turn during the scraping process, so as to complete the screening of large particles in the powder during the printing process, avoid the influence of the generated large particles on the printing effect, and improve the uniformity of powder spreading.

[0037] like Figure 5 As shown, it should be noted that the extended length of the first scraper 21 is H1, and the extended length of the second scraper 22 is H2. The extended length H1 of the first scraper 21 relative to the fixed part 1 is smaller than the extended length H2 of the second scraper 22 relative to the fixed part 1, that is, H1>H2. No specific limitation is made on the extended length H1 of the first scraper 21 and the extended length H2 of the second scraper 22. As long as the extended length H1 of the first scraper 21 is smaller than the extended length H2 of the second scraper 22, a stepped distribution is formed at the first scraper 21 and the second scraper 22, and the powder is gradually scraped and delivered during the movement. The powder can be metal powder or other granular powder, which is not specifically limited here.

[0038] like Figure 1 and Figure 3 As shown, specifically, in this embodiment, the connecting portion 3 is connected to the fixing portion 1, and a first clamping groove 31 is provided on a side of the connecting portion 3 away from the fixing portion 1, and the first clamping groove 31 is used to clamp with the scraper body 2. The connecting portion 3 and the scraper body 2 are clamped by the first clamping groove 31, which is convenient for disassembly and installation, and improves the flexibility of use of the scraper.

[0039] like Figure 5 As shown, preferably, one end of the first slot 31 along which it is guided is a closed end. When the scraper body 2 is engaged with the connecting portion 3 through the first slot 31, the closed end limits the scraper body 2 to prevent the scraper body 2 from moving in the first slot 31, thereby improving the installation accuracy of the scraper. The connecting portion 3 and the fixing portion 1 can be welded or connected in other fixed ways. The connection method between the connecting portion 3 and the fixing portion 1 is not specifically limited, as long as the connecting portion 3 and the fixing portion 1 are connected and fixed. At the same time, the connecting portion 3 and the fixing portion 1 can also be an integrated structure, which is more convenient when manufacturing the component structure and reduces the installation process.

[0040] like Figure 3 As shown, in some embodiments, a through hole 32 is provided at the bottom of the first card slot 31, and both the fixing portion 1 and the scraper body 2 are provided with mounting holes opposite to the through hole 32. The scraper further includes a fastener, which passes through the mounting hole of the fixing portion 1, the through hole 32 and the mounting hole of the scraper body 2 in sequence to connect and fix the fixing portion 1, the connecting portion 3 and the scraper body 2. Among them, the through holes 32 can be provided with 2, 4, 5, etc. along the guide interval of the first card slot 31. The number and position of the through holes 32 are not specifically limited here, as long as the connection and fixing requirements of the fixing portion 1, the connecting portion 3 and the scraper body 2 are met.

[0041] like Figure 5 As shown, specifically, in this embodiment, the blade thickness of the third scraper 23 at one end away from the fixed part 1 is greater than the blade thickness of the first scraper 21 and the blade thickness of the second scraper 22. The blade thickness of the third scraper 23 is M1, the blade thickness of the first scraper 21 is M2, and the blade thickness of the second scraper 22 is M3, that is, M1>M2 and M1>M3, so that the bottom stroke of the blade of the third scraper 23 is longer, that is, in the final paving process, the third scraper 23 can move a longer distance on the powder surface, ensuring the flatness of the powder paving, and the blade thickness M1 of the third scraper 23 is not specifically limited here.

[0042] like Figure 5As shown, specifically, in this embodiment, a second inclined surface 231 is provided on one side of the third scraper 23 close to the second scraper 22, and an angle θ is formed between the inclination direction of the second inclined surface 231 relative to the horizontal plane and the scraping direction, satisfying 45°≤θ≤90°. The angle θ between the inclination direction of the second inclined surface 231 relative to the horizontal plane and the scraping direction can be 45°, 60°, 75°, 90°, etc., and the angle θ between the inclination direction of the second inclined surface 231 relative to the horizontal plane and the scraping direction is not specifically limited.

[0043] like Figure 4-Figure 7 As shown, specifically, in this embodiment, a second slot 233 is provided on one side of the third scraper 23 away from the second scraper 22, and the scraper further comprises a rubber rod 232, which is engaged with the third scraper 23 through the second slot 233, and the bottom end of the rubber rod 232 and the end of the third scraper 23 away from the fixed portion 1 are in the same horizontal plane. The rubber rod 232 and the third scraper 23 are engaged and installed through the second slot 233, which is convenient for installation and disassembly, and improves the flexibility of the scraper. At the same time, the rubber rod 232 increases the stroke of the bottom end of the third scraper 23. After the third scraper 23 flattens the powder, the rubber rod 232 needs to flatten the powder for a second time, thereby ensuring the flatness of the powder.

[0044] like Figure 4-Figure 6 As shown, specifically, in this embodiment, the scraper also includes a fourth scraper 24, which is located between the second scraper 22 and the third scraper 23, and one end of the fourth scraper 24 away from the fixed portion 1 and one end of the third scraper 23 away from the fixed portion 1 are in the same horizontal plane. After the comb teeth 221 on the second scraper 22 filter the large particles of powder, the spread powder is pre-treated by the fourth scraper 24 to be flattened, and finally further flattened by the third scraper 23, thereby improving the uniformity and flatness of the scraper powder.

[0045] like Figure 5 and Figure 6 As shown, specifically, in this embodiment, the blade thickness of the fourth scraper 24 is greater than or equal to the blade thickness of the second scraper 22. The blade thickness of the fourth scraper 24 is M4, that is, the blade thickness of the fourth scraper 24 is M4 ≥ M3. The stroke of the bottom end of the fourth scraper 24 is relatively long. Here, the blade thickness of the fourth scraper 24 is not specifically limited to M4, which is convenient for paving the screened powder.

[0046] like Figure 5 As shown, specifically, in this embodiment, the bottom edge of the fourth scraper 24 close to the second scraper 22 is rounded. The rounded surface is a curved surface, which can contact the surface of the screened powder more smoothly, realize the flattening pretreatment of the powder, and improve the powder spreading efficiency of the scraper.

[0047] In some embodiments, the comb teeth 221 include: a first rack and a second rack, the length of the first rack is less than the length of the second rack, and the first rack and the second rack are alternately arranged in the same horizontal plane along a direction perpendicular to the scraping direction. The first rack and the second rack of different lengths are used to screen and split the powder accumulated between the first scraper 21 and the second scraper 22, so that the powder that meets the paving requirements can pass smoothly through the gap between the first rack and the second rack for paving, which is convenient for operation; Figure 6 As shown, in other embodiments, the length of the first rack is equal to the length of the second rack. There is no specific limitation on the length of the first rack and the length of the second rack, as long as the clearance requirement of the comb teeth 221 for screening powder is met.

[0048] like Figure 2 As shown, specifically, in this embodiment, a plurality of weight-reducing holes 11 are provided on the fixing portion 1 to reduce the mass of the fixing portion 1 and improve the accuracy of the movement of the scraper.

[0049] It should be noted that the distribution gaps between the first scraper 21, the second scraper 22 and the third scraper 23 and the gaps between the multiple comb teeth 221 can be adjusted according to the requirements of powder spreading flatness. Here, no specific limitations are made on the gap L1 between the first scraper 21 and the second scraper 22, the gap L2 between the second scraper 22 and the fourth scraper 24, the gap L3 between the fourth scraper 24 and the third scraper 23, and the gap L4 between two adjacent comb teeth 221.

[0050] At the same time, the utility model also provides a powder spreading device, including a driving component, a powder supply platform, a molding platform and any one of the scrapers above, the driving end of the driving component is connected to the fixed part 1, the driving component is used to drive the fixed part 1 to drive the scraper body 2 to move together and pass through the powder supply platform and the molding platform in sequence.

[0051] During operation, the operator completes the fixed connection between the fixed part 1 and the driving end of the driving component, and then processes the powder of the prepared material on the powder supply platform and adds the preset powder. After the addition is completed, the driving component drives the fixed part 1 to drive the scraper body 2 to move in the scraping direction. The first scraper 21, the second scraper 22 and the third scraper 23 on the scraper body 2 scrape and flatten the powder in the scraping direction in sequence as the driving component moves, and screens the large particles in the printed powder to avoid the influence of large particles generated during the printing process on the printing effect, facilitate operation, and ensure the uniformity of powder spreading.

[0052] In the description of the above embodiments, specific features, structures, materials or characteristics may be combined in a suitable manner in any one or more embodiments or examples.

[0053] The above is only a specific implementation of the utility model, but the protection scope of the utility model is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the utility model, which should be included in the protection scope of the utility model. Therefore, the protection scope of the utility model should be based on the protection scope of the claims.

Claims

1. A scraper, characterized in that: include: Fixed part; A scraper body, one end of which is connected to the fixed part, and the other end of the scraper body is provided with a first scraper, a second scraper and a third scraper arranged in sequence in the scraping direction, the extension length of the first scraper relative to the fixed part is less than the extension length of the second scraper relative to the fixed part, the first scraper has a first inclined surface on a side away from the second scraper, the cross-sectional area of ​​the first scraper gradually decreases downward in the vertical direction, the second scraper has a plurality of comb teeth spaced apart in a direction perpendicular to the scraping direction, the plurality of comb teeth are used to filter large particles of powder, the fixed end of the third scraper and an end away from the fixed part and an end of the second scraper away from the fixed part are in the same horizontal plane.

2. The scraper according to claim 1, characterized in that: It also includes a connecting portion, which is connected to the fixing portion. A first clamping groove is provided on a side of the connecting portion away from the fixing portion, and the first clamping groove is used for clamping with the scraper body.

3. The scraper according to claim 1, characterized in that: The blade tooth thickness of the third scraper at one end away from the fixing portion is greater than both the blade tooth thickness of the first scraper and the blade tooth thickness of the second scraper.

4. The scraper according to claim 3, characterized in that: A second inclined surface is provided on a side of the third scraper close to the second scraper, and an angle θ is formed between an inclination direction of the second inclined surface relative to a horizontal plane and the scraping direction, satisfying 45°≤θ≤90°.

5. The scraper according to claim 3, characterized in that: A second slot is provided on a side of the third scraper away from the second scraper. The scraper also includes a rubber rod, which is clamped with the third scraper through the second slot, and the bottom end of the rubber rod and the end of the third scraper away from the fixing portion are in the same horizontal plane.

6. The scraper according to claim 1, characterized in that: It also includes a fourth scraper, which is located between the second scraper and the third scraper, and one end of the fourth scraper away from the fixing portion and one end of the third scraper away from the fixing portion are in the same horizontal plane.

7. The scraper according to claim 6, characterized in that: The thickness of the teeth of the fourth scraper is greater than or equal to the thickness of the teeth of the second scraper.

8. The scraper according to claim 6, characterized in that: The bottom edge of the fourth scraper on a side close to the second scraper is rounded.

9. The scraper according to claim 1, characterized in that: The comb teeth include: a first rack and a second rack, the length of the first rack is smaller than the length of the second rack, and the first rack and the second rack are alternately arranged in the same horizontal plane along a direction perpendicular to the scraping direction.

10. A powder spreading device, characterized in that: It comprises a driving component, a powder supply platform, a molding platform and a scraper as described in any one of claims 1 to 9, wherein the driving end of the driving component is connected to the fixed part, and the driving component is used to drive the fixed part to drive the scraper body to move together and pass through the powder supply platform and the molding platform in sequence.

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