Cylinder temperature control structure and method based on bionic and diffusion welding laser selective melting equipment

Abstract

This invention relates to a biomimetic and diffusion welding laser selective melting equipment cylinder temperature control structure and method, belonging to the field of laser selective melting metal additive manufacturing. It includes: multiple cylinder components, which are fixedly connected to form a complete cylinder. Each cylinder component comprises an inner cylinder, an outer cylinder, and biomimetic flow channels. These flow channels are etched onto the surfaces of the inner and outer cylinders, the outer cylinder facing the inner cylinder, or the two opposing surfaces of the inner and outer cylinders. The inner and outer cylinders are welded together using vacuum diffusion welding. Fluid media circulate within the biomimetic flow channels to heat or cool the cylinder. This ensures uniform temperature distribution within the cylinder, ease of processing and maintenance, and allows for rapid cooling or heating with various cooling or heating media.

Description

Technical Field

[0001] This application pertains to the field of laser selective melting metal additive manufacturing, particularly a method for controlling cylinder temperature during and after printing. Background Technology

[0002] In recent years, with the rapid growth in market demand, especially in the aerospace field, for laser selective melting (LSM) metal additive manufacturing, LSM technology has developed rapidly due to its ability to form complex and intricate structures, short forming processes, and strong adaptability to various part sizes. Production has shifted from rapid prototyping to final, finished parts, and from single-piece and small-batch production to medium-batch production. Simultaneously, ensuring cylinder preheating and constant temperature control during the LSM printing process is crucial for guaranteeing part quality, and rapid cylinder cooling after printing to shorten post-processing time is an important method for increasing efficiency. However, this process requires ensuring uniform temperature distribution within the cylinder, ease of processing and maintenance, and the ability to rapidly cool or heat using various cooling or heating media. Summary of the Invention

[0003] The technical problem solved by this application is to overcome the shortcomings of the prior art and provide a cylinder temperature control structure and method for a biomimetic and diffusion welding laser selective melting equipment, which ensures uniform temperature distribution of the cylinder and is easy to process and maintain, and can perform rapid cooling or heating of various cooling or heating media.

[0004] The technical solution provided in this application is as follows: Based on the biomimetic and diffusion welding laser selective melting equipment cylinder temperature control structure, it includes: multiple cylinder components, which are fixedly connected to form a complete cylinder; Each cylinder assembly includes an inner cylinder, an outer cylinder, and biomimetic flow channels. These flow channels are etched onto the surface of the inner cylinder facing the outer cylinder, the surface of the outer cylinder facing the inner cylinder, or the two opposing surfaces of the inner and outer cylinders. The inner and outer cylinders are welded together using a vacuum diffusion welding method. Fluid media circulates within the biomimetic flow channels to heat or cool the cylinder.

[0005] Furthermore, the biomimetic design flow channel includes a main flow channel, branch flow channels, and capillary flow channels. Multiple branch flow channels are respectively arranged on both sides of the main flow channel. One end of the branch flow channel is connected to the main flow channel, and the other end of the branch flow channel extends away from the main flow channel to the edge of the cylinder assembly. The capillary flow channels are connected between the branch flow channels.

[0006] Furthermore, the end connecting the tributary to the main channel is the beginning end, and the angle between the flow direction of the fluid in the main channel and the direction from the beginning to the end of the tributary is less than 90°.

[0007] Furthermore, the ends of the branch channels are all connected to capillary channels.

[0008] Furthermore, the two ends of the main channel extend to the edge of the cylinder assembly, forming an inlet and an outlet respectively; the direction from the inlet to the outlet is the flow direction of the fluid in the main channel.

[0009] Furthermore, the inlet interface is no less than the outlet interface.

[0010] Furthermore, the main channel is connected to a drain channel near the bottom of the cylinder assembly, and the other end of the drain channel extends to the bottom of the cylinder assembly to form a drain interface.

[0011] Furthermore, the main channel is connected to an exhaust channel near the top of the cylinder block assembly, and the other end of the exhaust channel extends to the bottom of the cylinder block assembly to form an exhaust port.

[0012] Furthermore, multiple temperature measuring points are provided between the inner cylinder and the outer cylinder.

[0013] The temperature control method based on the cylinder temperature control structure of the biomimetic and diffusion welding laser selective melting equipment described above includes: during the printing process, a fluid medium with a temperature higher than the printing preheating temperature flows through the biomimetic design channel to achieve heating; when printing is completed, the fluid medium with a temperature higher than the printing preheating temperature is discharged, and a cooling medium is introduced into the biomimetic design channel for cooling; after the cylinder is cooled, the cooling medium is discharged.

[0014] In summary, this application includes at least the following beneficial technical effects: To meet the high-efficiency, rapid, and high-quality application requirements of laser selective melting (SLM) equipment, cylinder preheating and rapid cooling will be the future development direction. This invention achieves cylinder preheating before printing through a temperature control structure and method, thus ensuring higher product quality; it also achieves rapid cylinder cooling, ensuring rapid cooling of the printed product and accelerating the removal efficiency of the printed parts. This invention uses biomimetic design to make cylinder preheating and cooling faster and more uniform, further improving product quality. The cylinder assembly formed by etching-diffusion welding can withstand operation under various media, such as rapid preheating through high-temperature, high-pressure gas / liquid and rapid cooling through low-temperature, high-pressure gas / liquid, with convenient switching between preheating and cooling. Attached Figure Description

[0015] Figure 1 Axonometric drawing for assembling the forming cylinder body.

[0016] Figure 2 This is a schematic diagram of the inner and outer cylinder blocks.

[0017] Figure 3This is a schematic diagram of the outer cylinder block. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments disclosed in this application will be described in further detail below with reference to the accompanying drawings.

[0019] This application discloses a cylinder temperature control structure for a biomimetic and diffusion welding laser selective melting device, such as... Figure 1 As shown, it includes multiple cylinder block assemblies, which are fixedly connected to form a complete cylinder block. The fixed connection can be achieved by welding or fixing with screws, etc.

[0020] In this embodiment, four cylinder block assemblies are provided, and the four cylinder block assemblies are welded together.

[0021] Each cylinder assembly includes an inner cylinder 1, an outer cylinder 2, and a biomimetic flow channel 3. The biomimetic flow channel 3 is etched onto the surface of the inner cylinder 1 facing the outer cylinder 2, the surface of the outer cylinder 2 facing the inner cylinder 1, or the two opposing surfaces of the inner cylinder 1 and outer cylinder 2. The inner cylinder 1 and outer cylinder 2 are welded together using a vacuum diffusion welding method. The biomimetic flow channel 3 is used to flow a fluid medium for heating or cooling the cylinder.

[0022] like Figure 2 and Figure 3 As shown, the biomimetic flow channel 3 includes a main channel 31, branch channels 32, and capillary channels 33. Multiple branch channels 32 are arranged on both sides of the main channel 31. One end of each branch channel 32 connects to the main channel 31, and the other end extends away from the main channel 31, near the edge of the cylinder assembly. Capillary channels 33 connect the branch channels 32. The end of each branch channel 32 that connects to the main channel 31 is the starting end. The angle between the flow direction of the fluid in the main channel 31 and the direction from the starting end to the end of the branch channel is less than 90°. The ends of each branch channel 32 connect to the capillary channels 33 to ensure uniform fluid distribution.

[0023] The main flow channel 31 extends to the edge of the cylinder block assembly at both ends, forming an inlet port 8 and an outlet port 9 at each end. The direction from the inlet port 8 to the outlet port 9 is the flow direction of the fluid within the main flow channel 31. The inlet port 8 is located below the outlet port 9, or the inlet port 8 is not lower than the outlet port 9. Near the bottom of the cylinder block assembly, the main flow channel 31 is also connected to a drain channel 34, the other end of which extends to the bottom of the cylinder block assembly, forming a drain port 6. Near the top of the cylinder block assembly, the main flow channel is also connected to an exhaust channel 35, the other end of which extends to the bottom of the cylinder block assembly, forming an exhaust port 5.

[0024] When the fluid medium in the biomimetic flow channel 3 is liquid, the liquid enters through the inlet port 8, while the gas in the biomimetic flow channel 3 is discharged through the exhaust port 5 until the biomimetic flow channel 3 is filled with liquid. Then, the exhaust port 5 is closed, and the liquid steadily flows in through the inlet port 8, through the main flow channel 31, the branch flow channel 32, and the capillary flow channel 33, finally flowing out through the outlet port 9. When evacuation is not required, the drain port 6 is closed. When evacuation is required, the drain port 6 is opened, and the liquid flows out through the drain port 6.

[0025] When the fluid medium in the biomimetic flow channel 3 is gas, the gas enters through the inlet port 8, and simultaneously exits through the exhaust port 5 until the flow channel 3 is filled with the required medium gas. At this point, the exhaust port 5 is closed, and the medium gas flows steadily in through the inlet port 8, passing through the main flow channel 31, branch flow channel 32, and capillary flow channel 33, finally exiting through the outlet port 9. Since the gas does not require liquid evacuation, the drain port 6 remains closed. The gas is finally discharged through the exhaust port 5.

[0026] This embodiment is based on a cylinder temperature control structure formed by combining four or more inner cylinders 1, outer cylinders 2, biomimetic design flow channels 3, inlet ports 8, outlet ports 9, exhaust ports 5, drain ports 6, and temperature measuring points 7. The inner cylinder 1 is a key component that ensures the vertical movement and sealing of the printing equipment. The biomimetic design flow channels 3 create a shape that evenly distributes the cylinder temperature. This shape is etched onto the outer cylinder 2 using etching technology. Then, the inner cylinder 1 and outer cylinder 2 are welded together using vacuum diffusion welding technology to ensure structural strength. Finally, the cylinder assembly is achieved through multi-piece splicing technology.

[0027] This invention enables the entry and exit of heating or cooling media through inlet interface 8 and outlet interface 9, thereby ensuring that the inner cylinder 1 and inner cylinder 2 meet different heating / cooling requirements during and after printing. This method is applicable to various laser selective melting additive manufacturing equipment, has strong applicability, and can control temperature at different process stages.

[0028] This invention utilizes a biomimetic flow channel 3 to facilitate the entry and exit of different media into and out of the cylinder, achieving uniform temperature distribution and enabling heating / cooling operations. This biomimetic flow channel 3 can be designed like the vein distribution of a leaf or the blood vessel distribution of an animal. Such a design can be planar or three-dimensional. Traditional machining methods for such designs suffer from limitations such as inability to process, long processing times, and poor precision. Therefore, an etching method is used to etch the planar or three-dimensional flow channel design onto the outer cylinder 2. Diffusion welding technology is then used to connect the inner cylinder 1 and the outer cylinder 2. This connection improves the pressure-bearing capacity of the flow channel, allowing it to handle not only normal pressure and temperature media but also high temperature and high pressure media, thus enabling diverse heating / cooling media selection to meet different heating / cooling control needs. Venting and discharge of the media are achieved through the exhaust port 5 and the drain port 6, allowing for rapid switching between different media to meet different temperature control requirements. The heating medium can be high-temperature, high-pressure steam, CO2, or other heat media, while the cooling medium can be water, R134a, or other refrigerants.

[0029] By designing the biomimetic flow channel 3, the overall temperature uniformity of the cylinder is ensured.

[0030] Example 1 ① The cylinder temperature control method of the laser selective melting equipment based on the above scheme and the biomimetic and etching-diffusion welding technology includes four or more inner cylinders 1, outer cylinders 2, biomimetic design flow channels 3, inlet interface 8, outlet interface 9, exhaust interface 5, drain interface 6, temperature measuring points 7 and other components. ② A biomimetic flow channel 3 is designed and etched onto the outer cylinder 2. It is then connected to the inner cylinder 1 by vacuum diffusion welding and assembled from multiple parts to form the cylinder. ③ During the printing process, the temperature is raised by using a medium with a temperature higher than the printing preheating temperature. For example, if the printing preheating temperature is 100℃, the inlet and outlet ports 8 and 9 are used to allow the inflow and outflow of high-temperature and high-pressure water vapor of >1 bar and >100℃ to achieve the temperature rise. The temperature measurement point 7 is used to detect whether the predetermined temperature has been reached and the flow rate of water vapor is adjusted to achieve temperature stability during the printing process. ④ When printing is complete, close the inlet port 8 and the outlet port 9, and open the exhaust port 5 and the drain port 6 to drain excess steam and water; close the exhaust port 5 and the drain port 6, and open the inlet port 8 and the outlet port 9 to introduce cooling water. By adjusting the flow rate of the cooling water, the temperature of the cylinder can be cooled quickly, shortening the part removal time. ⑤ After the cylinder block cools down, close the inlet port 8 and the outlet port 9, and open the exhaust port 5 and the drain port 6 to drain the cooling medium and ensure the long-term stability of the cylinder block. ⑥ If a new print job is required, repeat steps 3-5.

[0031] Example 2 ① The cylinder temperature control method of the laser selective melting equipment based on the above scheme and the biomimetic and etching-diffusion welding technology includes four or more inner cylinders 1, outer cylinders 2, biomimetic design flow channels 3, inlet interface 8, outlet interface 9, exhaust interface 5, drain interface 6, temperature measuring points 7 and other components. ② A biomimetic flow channel 3 is designed and etched onto the outer cylinder 2. It is then connected to the inner cylinder 1 by vacuum diffusion welding and assembled from multiple parts to form the cylinder. ③ During the printing process, the temperature is raised by using a medium with a temperature higher than the printing preheating temperature. For example, if the printing preheating temperature is 100℃, the inlet and outlet interfaces 8 and 9 are used to allow the inflow and outflow of high-temperature and high-pressure CO2 at temperatures >90 bar and >100℃, thereby raising the temperature. Temperature measurement point 7 is used to detect whether the predetermined temperature has been reached, and the flow rate of CO2 is adjusted to stabilize the temperature during the printing process. ④ When printing is complete, close the inlet port 8 and the outlet port 9, and open the exhaust port 5 and the drain port 6 to vent excess CO2; close the exhaust port 5 and the drain port 6, and open the inlet port 8 and the outlet port 9 to introduce refrigerant such as R134a. By adjusting the flow rate of the refrigerant, the temperature of the cylinder can be cooled quickly, shortening the time for removing parts. ⑤ After the cylinder block cools down, close the inlet port 8 and the outlet port 9, and open the exhaust port 5 and the drain port 6 to drain the cooling medium and ensure the long-term stability of the cylinder block. ⑥ If a new print job is required, repeat steps 3-5.

[0032] The contents not described in detail in this application specification are common knowledge to those skilled in the art.

[0033] The present application has been described in detail above with reference to specific embodiments and exemplary examples; however, these descriptions should not be construed as limiting the present application. Those skilled in the art will understand that various equivalent substitutions, modifications, or improvements can be made to the technical solutions and implementation methods of the present application without departing from the spirit and scope of the present application, and all such modifications and improvements fall within the scope of the present application. The scope of protection of the present application is determined by the appended claims.

Claims

1. A temperature control method based on the cylinder temperature control structure of a biomimetic and diffusion welding laser selective melting equipment, characterized in that, include: During the printing process, a fluid medium with a temperature higher than the printing preheating temperature flows through the biomimetic design channel (3) to achieve heating; When printing is complete, the fluid medium with a temperature higher than the preheating temperature of printing is discharged, and a cooling medium is introduced into the biomimetic design channel (3) for cooling. After the cylinder block cools down, the cooling medium is discharged. The temperature control structure of the cylinder body of the biomimetic and diffusion welding laser selective melting equipment includes: multiple cylinder body components, which are fixedly connected to form a complete cylinder body; Each cylinder assembly includes an inner cylinder (1), an outer cylinder (2), and a biomimetic flow channel (3). The biomimetic flow channel (3) is etched onto the surface of the inner cylinder (1) facing the outer cylinder (2), the surface of the outer cylinder (2) facing the inner cylinder (1), or the two opposing surfaces of the inner cylinder (1) and the outer cylinder (2). The inner cylinder (1) and the outer cylinder (2) are welded together by a vacuum diffusion welding method. The biomimetic flow channel (3) is used to circulate fluid medium to heat or cool the cylinder.

2. The temperature control method for the cylinder temperature control structure of the biomimetic and diffusion welding laser selective melting equipment according to claim 1, characterized in that: The biomimetic design flow channel (3) includes a main flow channel (31), a branch flow channel (32) and a capillary flow channel (33). Multiple branch flow channels (32) are respectively arranged on both sides of the main flow channel (31). One end of the branch flow channel (32) is connected to the main flow channel (31), and the other end of the branch flow channel (32) extends away from the main flow channel (31) and approaches the edge of the cylinder assembly. The capillary flow channel (33) is connected between the branch flow channels (32).

3. The temperature control method for the cylinder temperature control structure of the biomimetic and diffusion welding laser selective melting equipment according to claim 2, characterized in that: The connection end between the branch channel (32) and the main channel (31) is the first end, and the angle between the flow direction of the fluid in the main channel (31) and the direction from the first end to the end of the branch channel (32) is less than 90°.

4. The temperature control method for the cylinder temperature control structure of the biomimetic and diffusion welding laser selective melting equipment according to claim 2, characterized in that: The ends of each branch channel (32) are connected to a capillary channel (33).

5. The temperature control method for the cylinder temperature control structure of the biomimetic and diffusion welding laser selective melting equipment according to claim 2, characterized in that: The two ends of the main channel (31) extend to the edge of the cylinder assembly, forming an inlet (8) and an outlet (9) respectively; the direction from the inlet (8) to the outlet (9) is the flow direction of the fluid in the main channel (31).

6. The temperature control method for the cylinder temperature control structure of the biomimetic and diffusion welding laser selective melting equipment according to claim 5, characterized in that: The inlet interface (8) is lower than the outlet interface (9).

7. The temperature control method for the cylinder temperature control structure of the biomimetic and diffusion welding laser selective melting equipment according to claim 2, characterized in that: The main channel (31) is connected to a drain channel (34) near the bottom of the cylinder assembly. The other end of the drain channel (34) extends to the bottom of the cylinder assembly to form a drain interface (6).

8. The temperature control method for the cylinder temperature control structure of the biomimetic and diffusion welding laser selective melting equipment according to claim 2, characterized in that: The main channel (31) is connected to an exhaust channel (35) near the top of the cylinder block assembly. The other end of the exhaust channel (35) extends to the top of the cylinder block assembly to form an exhaust port (5).

9. The temperature control method for the cylinder temperature control structure of the biomimetic and diffusion welding laser selective melting equipment according to claim 1, characterized in that: Multiple temperature measuring points (7) are provided between the inner cylinder (1) and the outer cylinder (2).

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