SLM (Selective Laser Melting) rapid soft scraper replacing device

Abstract

The invention relates to an SLM device for rapidly replacing a soft scraper, and belongs to the technical field of metal additive manufacturing. The invention also discloses a method. Comprising a supporting rod group, a scraper connecting mechanism (2), a soft scraper (3), a soft scraper clamping device (4) and a scraper body structure (6), the outer portion of the scraper body structure (6) is connected with an external driving motor through the scraper connecting mechanism (2), the motor drives the three supporting rods to rotate clockwise and drives the soft scraper (3) to rotate, transposition of the soft scraper (3) is completed, time consumed in the process is short, and laser printing time is not occupied as well. Therefore, the operation of quickly replacing the soft scraper (3) without opening the cabin is realized, the part printing quality and the printing efficiency can be effectively improved, and the product rejection rate is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of metal additive manufacturing, and in particular relates to a SLM quick-replacement soft scraper device. Background Art

[0002] 3D printing is a new technology that has developed rapidly in recent years. It has gradually become an important means of production in the manufacturing industry. Among the many 3D printing technologies, metal powder 3D printing technology is the most representative. It will become a production model that is as important as additive and subtractive manufacturing and equal material manufacturing in the future, and the impact it brings cannot be underestimated.

[0003] Metal powder 3D printing technology is an advanced technology that uses laser beams to melt metals, ceramics, polymers and other materials layer by layer to manufacture objects. Compared with traditional manufacturing methods, metal powder 3D printing technology has the advantages of fast manufacturing speed, design freedom, molding accuracy, and no need for molds. Therefore, it is widely used in weapons and equipment, aerospace, medical electronics and other fields.

[0004] Scrapers are important structural components of metal powder 3D printing. Powder spreading devices usually have several options, such as metal scrapers, ceramic scrapers, and rubber scrapers. Due to their shape and hardness, hard scrapers can compact powder during the powder spreading process and have stronger wear resistance, providing a denser powder bed, ensuring stable powder spreading even during long production processes. However, the friction generated by hard scrapers during the powder spreading process is all transferred to the parts, limiting the manufacturability of high aspect ratios. They are very sensitive to inappropriate process parameters, may cause powder contamination and slag inclusions due to wear, and are extremely expensive.

[0005] The main advantage of a soft scraper is that it reduces the force of the scraper on the part during the powder coating process. Since the soft scraper is more flexible, if the friction is too great, the scraper can give way; if the part deforms and sticks in the powder bed, the soft scraper can adapt to the contour of the part to a certain extent, and can more easily manufacture high aspect ratio parts, reducing the possibility of work interruptions due to scraper blockage, and the cost is extremely low.

[0006] However, the soft scraper is easily damaged during the long printing process due to the local protrusion structure caused by process parameters or part deformation, resulting in strip-shaped powder layers in the subsequent powder spreading process, resulting in uneven powder spreading, which seriously affects the printing quality of the parts. According to existing reports, the current solution is to stop the machine to replace the soft scraper, and there is even a risk of scrapping the parts, reducing production efficiency and wasting labor and material costs. Therefore, it is particularly important to design a SLM fast replacement soft scraper device and replacement method. Summary of the invention

[0007] 1. Technical issues to be resolved

[0008] The technical problem to be solved by the present invention is how to provide a SLM quick-replacement soft scraper device to solve the problem of automatically replacing the soft scraper without stopping the machine, improve the uniformity of the powder layer, and reduce the scrap rate of parts and the cost of equipment use.

[0009] (II) Technical solution

[0010] In order to solve the above technical problems, the present invention proposes an SLM quick-change soft scraper device, comprising: a support rod group, a scraper connecting mechanism 2, a soft scraper 3, a soft scraper clamping device 4, and a scraper body structure 6;

[0011] The support rod group is fixed in the scraper body structure 6, which includes: a middle support rod 1, a left support rod 7, and a right support rod 5. The middle support rod 1 has the same overall structure as the left support rod 7 and the right support rod 5, and is arranged in a triangular structure. A groove is provided on each support rod. The soft scraper 3 is supported by the grooves on the three support rods, and a soft scraper clamping device 4 is provided outside the lower part of the soft scraper 3;

[0012] The scraper body structure 6 is externally connected to an external drive motor via a scraper connection mechanism 2 , and the motor drives the three support rods to rotate clockwise, and drives the soft scraper 3 to rotate, thereby completing the position change of the soft scraper 3 .

[0013] The middle support rod 1 can also move up and down by being driven by an external motor, and the soft scraper 3 is put into a relaxed state by the downward movement of the middle support rod 1;

[0014] The soft scraper 3 is put into a tensioned state by the upward movement of the middle support rod 1 .

[0015] The soft scraper clamping device 4 is placed between the left support rod 7 and the right support rod 5 at the lower part of the scraper body structure 6, and is used to clamp the soft scraper 3 below.

[0016] The flexible scraper clamping device 4 is provided with a flexible chain structure 8 on the outside, and the flexible chain structure 8 is used to lock the bottom soft scraper 3 during the loosening and pulling process before and after the soft scraper 3 is replaced.

[0017] Among them, when the bottom soft scraper 3 is worn, the scraper body structure 6 is driven by the driving motor to run to the end of the powder supply cylinder 9, the soft scraper clamping device 4 loosens the scraper, and the three support rods rotate clockwise to replace the worn part of the soft scraper 3. After completion, the soft scraper clamping device 4 clamps the scraper.

[0018] Among them, when the soft scraper 3 is worn at the bottom and both sides, the scraper body structure 6 is driven by the driving motor to run to the end of the powder supply cylinder 9, the soft scraper clamping device 4 loosens the scraper, the three support rods extend outward, and the middle support rod 1 moves downward, so that the soft scraper 3 is in a relaxed state and a new soft scraper 3 is replaced.

[0019] After manually replacing the new soft scraper, the middle support rod 1 is moved upward and tightened, and the three support rods are retracted inward to complete the replacement of the soft scraper.

[0020] The powder supply cylinder 9 is fixed on the workbench by screws 10 .

[0021] (III) Beneficial effects

[0022] The present invention proposes a SLM quick-change soft scraper device, which can effectively improve the printing quality of parts, improve printing efficiency, and reduce product scrapping rate. At the same time, the size of the quick-change soft scraper device can be designed according to the SLM printing equipment of different formats in the market, and can be compatible with the use requirements of various models of products. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a cross-sectional view of the quick-replacement soft scraper device of the present invention;

[0024] Figure 2 It is a schematic diagram of the soft scraper clamping device;

[0025] Figure 3 This is a schematic diagram of the middle support rod of the soft scraper;

[0026] Figure 4 Schematic diagram of the soft scraper replacement process. DETAILED DESCRIPTION

[0027] In order to make the purpose, content and advantages of the present invention more clear, the specific implementation methods of the present invention are further described in detail below in conjunction with the drawings and examples.

[0028] A SLM (selective laser melting) quick-replacement soft scraper device, comprising: a support rod group, a scraper connection mechanism 2, a soft scraper 3, a soft scraper clamping device 4, and a scraper body structure 6;

[0029] The scraper body structure 6 is connected to the operating mechanism in the SLM cabin to achieve reciprocating movement of powder spreading. The entire operation is completed through electrical control, and the operation signal can be combined with the trajectory planning software to change the fixed number of printing layers or fixed printing time and one-touch external control button manual control. If a fixed number of printing layers or fixed printing time control is adopted, an early alarm function is prefabricated.

[0030] The support rod group is fixed in the scraper body structure 6, which includes: a middle support rod 1, a left support rod 7, and a right support rod 5. The middle support rod 1 has the same overall structure as the left support rod 7 and the right support rod 5, and is arranged in a triangular structure. A groove is provided on each support rod. The soft scraper 3 is supported by the grooves on the three support rods, and a soft scraper clamping device 4 is provided outside the lower part of the soft scraper 3;

[0031] The scraper body structure 6 is externally connected to an external drive motor via a scraper connection mechanism 2 , and the motor drives the three support rods to rotate clockwise, and drives the soft scraper 3 to rotate, thereby completing the position change of the soft scraper 3 .

[0032] The middle support rod 1 can also move up and down by being driven by an external motor, and the soft scraper 3 is put into a relaxed state by the downward movement of the middle support rod 1;

[0033] The soft scraper 3 is put into a tensioned state by the upward movement of the middle support rod 1 .

[0034] The soft scraper clamping device 4 is placed between the left support rod 7 and the right support rod 5 at the lower part of the scraper body structure 6, and is used to clamp the soft scraper 3 below.

[0035] The flexible scraper clamping device 4 is provided with a flexible chain structure 8 on the outside, and the flexible chain structure 8 is used to lock the bottom soft scraper 3 during the loosening and pulling process before and after the soft scraper 3 is replaced.

[0036] When the part is sliced ​​and continuously printed, the printed part is slightly deformed due to the thin-wall structure, support design and process parameters, resulting in the local forming position of the part in the single-layer or multi-layer slice being higher than the powder plane of the forming cylinder. Therefore, when the scraper body structure 6 reciprocates, the bottom soft scraper 3 will be worn when it contacts the protruding part of the part. When the degree of wear gradually increases, when there are slight strip-shaped gaps in the powder layer, but it does not affect the overall part printing quality, the scraper body structure 6 is operated to the end of the powder supply cylinder 9 through an electrical signal, and the soft scraper clamping device 4 is loosened. The three groups of support rods rotate clockwise to replace the soft scraper 3 of the worn part. After completion, the soft scraper clamping device 4 clamps the broach and realizes normal reciprocating powder spreading operation. This process is carried out synchronously during the laser printing process, so it does not affect the printing time. Due to the reciprocating printing process, the part of the forming cylinder and the powder plane are adaptively leveled.

[0037] When wear occurs at all positions of the soft scraper 3, the soft scraper 3 must be replaced. Similarly, the scraper body structure 6 moves to the end of the powder supply cylinder 9, and the soft scraper clamping device 4 loosens the scraper. At this time, the three groups of support rods extend outward, and the middle support rod 1 moves downward. The soft scraper 3 is in a relaxed state. After the glove box and the new soft scraper 3 in the prefabricated SLM cabin are manually replaced, the middle support rod 1 moves up and tightens, and the three groups of support rods retract inward to complete the semi-braking quick replacement of the soft scraper. This process is time-consuming and does not occupy the laser printing time. Therefore, the quick replacement of the soft scraper 3 without opening the cabin can effectively improve the printing quality and printing efficiency of parts and reduce the product scrap rate.

[0038] The powder supply cylinder 9 is fixed on the workbench by screws 10 .

[0039] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A SLM quick-change soft scraper device, characterized in that: It comprises: a support rod group, a scraper connecting mechanism (2), a soft scraper (3), a soft scraper clamping device (4), and a scraper body structure (6); The support rod group is fixed in the scraper body structure (6), and comprises: a middle support rod (1), a left support rod (7), and a right support rod (5); the middle support rod (1) has the same overall structure as the left support rod (7) and the right support rod (5), and is arranged in a triangular structure; each support rod is provided with a groove; the soft scraper (3) is supported by the grooves on the three support rods; and a soft scraper clamping device (4) is provided outside the lower part of the soft scraper (3); The scraper body structure (6) is externally connected to an external drive motor via a scraper connection mechanism (2), and the motor drives the three support rods to rotate clockwise, thereby driving the soft scraper (3) to rotate, thereby completing the position change of the soft scraper (3).

2. The SLM quick-change soft scraper device according to claim 1, characterized in that: The middle support rod (1) can also move up and down by being driven by an external motor, and the soft scraper (3) is put into a relaxed state by the downward movement of the middle support rod (1); The soft scraper (3) is put into a tensioned state by the upward movement of the middle support rod (1).

3. The SLM quick-change soft scraper device according to claim 2, characterized in that: The soft scraper clamping device (4) is placed between the left end support rod (7) and the right end support rod (5) at the lower part of the scraper body structure (6) and is used to clamp the soft scraper (3) at the lower part.

4. The SLM quick-change soft scraper device according to claim 3, characterized in that: The soft scraper clamping device (4) is provided with a flexible chain structure (8) on the outside, and the flexible chain structure (8) is used to lock the bottom soft scraper (3) during the loosening and pulling processes before and after the soft scraper (3) is replaced.

5. The SLM quick-change soft scraper device according to claim 4, characterized in that: When the bottom soft scraper (3) is worn, the scraper body structure (6) is driven by the driving motor to move to the end of the powder supply cylinder (9), the soft scraper clamping device (4) loosens the scraper, and the three support rods rotate clockwise to replace the worn part of the soft scraper (3). After completion, the soft scraper clamping device (4) clamps the scraper.

6. The SLM quick-change soft scraper device according to claim 5, characterized in that: When the bottom and both sides of the soft scraper (3) are worn, the scraper body structure (6) is driven by a driving motor to move to the end of the powder supply cylinder (9), the soft scraper clamping device (4) is loosened, the three support rods extend outward, and the middle support rod (1) moves downward, so that the soft scraper (3) is in a relaxed state and a new soft scraper (3) is replaced.

7. The SLM quick-change soft scraper device according to claim 6, characterized in that: After the new soft scraper is manually replaced, the middle support rod (1) is moved upward and tightened, and the three support rods are retracted inwards, completing the replacement of the soft scraper.

8. The SLM quick-change soft scraper device according to claim 7, characterized in that: The powder supply cylinder (9) is fixed on the workbench by screws (10).

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