Inner and outer cylinder structures using laser powder melting technology

Abstract

The present invention discloses an inner and outer cylinder structure of a laser powder melting forming technology, comprising an outer cylinder body, an inner cylinder body, a piston, a piston lifting drive device and an inner cylinder body lifting drive device. The upper ends of the outer cylinder body and the inner cylinder body both form an opening structure. The inner cylinder body is inserted into the outer cylinder body in a manner that is stopped in the circumferential direction and can slide in the axial direction. The inner cylinder body can extend out of the outer cylinder body to a set length through the opening structure at the upper end of the outer cylinder body. The piston is sealed and inserted into the inner cylinder body in a manner that is stopped in the circumferential direction and can slide in the axial direction. The upper end surface of the piston forms a molding surface. The piston lifting drive device drives the piston to move up and down in the inner cylinder body. The inner cylinder body lifting drive device drives the inner cylinder body to move up and down in the outer cylinder body. The precision of the present invention is easy to control, can be tested offline, and is convenient for taking out parts, creating good conditions for the structural arrangement of the forming chamber, and the overall height is low.

Description

Technical Field

[0001] The present invention relates to forming equipment for SLM processing, and in particular to an inner and outer cylinder structure of laser powder melting forming technology. Background Art

[0002] SLM technology overcomes the challenges of traditional methods for manufacturing complex metal parts. It can directly form nearly fully dense metal parts with excellent mechanical properties. Therefore, the use of SLM technology for product processing and forming has become widespread. SLM equipment uses a forming cylinder and a powder spreading device to support the powder and product. Currently, the forming cylinder consists of a cylinder body fixed to a frame and a piston located within the cylinder body. The forming cylinder is fixedly mounted on the SLM equipment and cannot be separated from the frame, making it difficult to perform various tests on the cylinder body. Furthermore, after the workpiece is processed, the forming box generally needs to be raised and removed to expose the product and remove it. This is very inconvenient, and the overall height of the forming cylinder is large, resulting in a high overall height of the SLM equipment, reaching 3.5 times the stroke of the forming cylinder piston, and taking up a large amount of space. Summary of the Invention

[0003] In order to make up for the above shortcomings, the present invention provides an inner and outer cylinder structure of laser powder melting forming technology. The cylinder height of the inner and outer cylinder structure of the laser powder melting forming technology can be retracted, which is convenient for material removal after processing. It can be separated from the frame of the SLM equipment for testing, and the overall height is low.

[0004] The technical solution adopted by the present invention to solve its technical problems is: an inner and outer cylinder structure of laser powder melting forming technology, including an outer cylinder body, an inner cylinder body, a piston, a piston lifting drive device and an inner cylinder body lifting drive device, the upper ends of the outer cylinder body and the inner cylinder body both form an opening structure, the inner cylinder body is stopped in the circumferential direction and can slide in the axial direction and is inserted into the outer cylinder body, the inner cylinder body can extend out of the outer cylinder body to a set length through the opening structure at the upper end of the outer cylinder body, the piston is stopped in the circumferential direction and can slide in the axial direction and is sealed and inserted into the inner cylinder body, the upper end surface of the piston forms a molding surface, the piston lifting drive device drives the piston to move up and down in the inner cylinder body, and the inner cylinder body lifting drive device drives the inner cylinder body to move up and down in the outer cylinder body.

[0005] As a further improvement of the invention, the upper end surface of the piston is covered with a formed base plate, and the formed base plate can be completely extended to the outside of the inner cylinder opening structure, and the side wall of the formed base plate is provided with a socket for inserting a forklift fork.

[0006] As a further improvement of the invention, the upper end opening of the outer cylinder body forms a shrinking structure with radially shrunk dimensions, the outer side wall of the inner cylinder body is dynamically sealed with the inner side wall of the upper end opening of the outer cylinder body through a seal, and the inner cylinder drive device is accommodated in the cavity formed between the inner side wall of the outer cylinder body and the outer side wall of the inner cylinder body.

[0007] As a further improvement of the invention, the inner cylinder body is a straight cylindrical structure with openings at both ends. A connecting rod is fixed to the lower end of the piston, and the lower end of the connecting rod extends outward from the opening at the lower end of the inner cylinder body. A connecting plate is fixed to the lower end of the connecting rod. The piston lifting drive device is accommodated in the cavity formed between the inner wall of the outer cylinder body and the outer wall of the inner cylinder body, and the piston lifting drive device is connected to the connecting plate and drives its lifting movement.

[0008] As a further improvement of the invention, a piston lifting guide rail and an inner cylinder lifting guide rail are fixedly provided on the inner side wall of the outer cylinder body, and the connecting plate and the outer side wall of the inner cylinder body are respectively stopped in the circumferential direction and can slide axially on the piston lifting guide rail and the inner cylinder lifting guide rail.

[0009] As a further improvement of the invention, the piston lifting drive device, piston lifting guide rail, inner cylinder lifting drive device and inner cylinder lifting guide rail are each two, the two piston lifting drive devices and the two piston lifting guide rails are symmetrically distributed inside the two opposite sides of the outer cylinder body, and the two inner cylinder lifting drive devices and the two inner cylinder lifting guide rails are symmetrically distributed inside the other two opposite sides of the outer cylinder body.

[0010] As a further improvement of the invention, the cross-section of the inner cylinder body is a square structure, and the outer cylinder body includes a cylinder barrel, a cylinder head and a cylinder bottom. The cylinder head and the cylinder bottom are respectively fixedly installed on the upper and lower ends of the cylinder barrel. The cylinder head includes a square frame-shaped main body matching the outer side wall of the inner cylinder body and a baffle located on the outer side surface of the lower end of the square frame-shaped main body. The baffle extends radially outward from the outer side wall of the square frame-shaped main body. The cylinder barrel of the outer cylinder body is a cylindrical body with a cross-section consistent with the overall structural shape of the square frame-shaped main body and the baffle of the cylinder head. The cylinder bottom is a flat plate structure consistent with the cross-sectional shape of the cylinder barrel.

[0011] As a further improvement of the invention, the piston lifting drive device includes a first servo motor and a first screw rod. The first servo motor is fixedly mounted on the outer cylinder body. The first screw rod is axially stopped and rotatable in the circumferential direction in the cavity formed between the outer cylinder body and the inner cylinder body. The first servo motor drives the first screw rod to rotate, and the first screw rod is movably screwed to the connecting plate.

[0012] As a further improvement of the invention, the inner cylinder driving device includes a second servo motor, a second screw and a nut sleeve. An outer lug plate is fixedly provided on the outer side wall of the inner cylinder body. The second screw is fixedly mounted on the outer lug plate on the outer side of the inner cylinder body. The axial direction of the second screw is parallel to the axial direction of the inner cylinder body. The nut sleeve is rotatable in the circumferential direction and is axially stopped on the inner side wall of the outer cylinder body. The nut sleeve is movably screwed to the outside of the second screw rod. The second servo motor is fixedly mounted on the outer cylinder body. The second servo motor drives the nut sleeve to rotate.

[0013] As a further improvement of the invention, an intermediate cylinder body and an intermediate cylinder body driving device are also provided. At least one intermediate cylinder body is stopped in the circumferential direction from the inside to the outside and can slide relatively in the axial direction to form an intermediate cylinder body group. The intermediate cylinder body group is inserted between the outer cylinder body and the inner cylinder body. The intermediate cylinder body driving device drives the intermediate cylinder body to lift and lower.

[0014] The beneficial technical effect of the present invention is: the present invention sets an independent guiding system in the outer cylinder body, which is unrelated to the frame. The piston and the inner cylinder are guided based on the outer cylinder, which is a "non-assembled rigid body". The guiding basis is single and the accuracy is easy to control. It can be tested for independent inch movement and full-stroke displacement offline, and 1000 to 5000 times can be tested to ensure the reliability of the most core inch movement and longitudinal movement. It can also perform long-term offline heating for temperature testing, as well as offline room temperature and high temperature powder and air tightness testing. After the inner cylinder body of the present invention moves down into the outer cylinder body, the molded parts are exposed and can be forked, which is very convenient for taking parts, creating good conditions for the structural layout of the forming chamber, and the overall total height is 2.5 to 3.0S, which is less than the traditional 3.5S (S is the stroke). BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the structural principle of the present invention;

[0016] Figure 2 for Figure 1 Middle BOC section view;

[0017] Figure 3 Schematic diagram of the steps for forming a product according to the present invention;

[0018] Figure 4 This is a material taking state diagram using the present invention. DETAILED DESCRIPTION

[0019] Embodiment: An inner and outer cylinder structure of a laser powder melting forming technology includes an outer cylinder body 1, an inner cylinder body 2, a piston 3, a piston lifting drive device and an inner cylinder body lifting drive device. The upper ends of the outer cylinder body 1 and the inner cylinder body 2 form an opening structure. The inner cylinder body 2 is inserted into the outer cylinder body 1 so as to be stopped in the circumferential direction and able to slide in the axial direction. The inner cylinder body 2 can extend out of the outer cylinder body 1 to a set length through the opening structure at the upper end of the outer cylinder body 1. The piston 3 is stopped in the circumferential direction and can slide in the axial direction and is sealed and inserted into the inner cylinder body 2. The upper end surface of the piston 3 forms a molding surface. The piston lifting drive device drives the piston 3 to move up and down in the inner cylinder body 2, and the inner cylinder body lifting drive device drives the inner cylinder body 2 to move up and down in the outer cylinder body 1.

[0020] When using this telescopic cylinder for product laser forming, first raise the inner cylinder body 2 and seal it with the bottom surface of the scanning plane of the forming chamber, then raise the piston 3 so that the forming surface on the piston 3 is flush with the bottom surface of the scanning plane, and the laser performs laser scanning and forming on the forming surface on the piston 3. After the product is formed, the inner cylinder descends, and the formed product can be exposed from the cylinder body, which is convenient for forklift to insert and take out. When taking out the material, there is no need to move the forming box or the forming cylinder, and the material taking is convenient and fast. Moreover, due to this structure, the cylinder body forming height is telescopic, which greatly reduces the overall height, greatly reduces the overall height of the SLM equipment, and saves space.

[0021] The upper surface of the piston 3 is covered with a forming base plate 4, which can be fully extended outside the opening structure of the inner cylinder 2. The side wall of the forming base plate 4 is provided with a socket 5 for inserting a forklift fork. The product is formed on the forming base plate 4. After forming is completed, the forming base plate 4 can be inserted and removed by forklift, making it convenient to remove the product.

[0022] The upper end opening of the outer cylinder body 1 forms a radially shrunk necking structure, and the outer side wall of the inner cylinder body 2 is dynamically sealed with the inner side wall of the upper end opening of the outer cylinder body 1 through a seal, and the inner cylinder driving device is accommodated in the cavity formed between the inner side wall of the outer cylinder body 1 and the outer side wall of the inner cylinder body 2. The outer cylinder body 1 is designed as a necking structure, and the necking structure is used to radially position the inner cylinder body 2. A cavity for accommodating the driving device is formed between the inner cylinder body 2 and the outer cylinder body 1, so that the driving device does not rely on the frame of the SLM equipment. The telescopic cylinder is separated from the frame, and independent inch and full stroke displacement tests, long-term offline heating temperature tests, and room temperature and high temperature powder tightness and airtightness tests can be achieved offline, avoiding the need to perform tests on the frame and affect other components of the SLM equipment.

[0023] The inner cylinder body 2 is a straight cylindrical structure with openings at both ends. A connecting rod 6 is fixed to the lower end of the piston 3. The lower end of the connecting rod 6 extends outside the opening at the lower end of the inner cylinder body 2, and a connecting plate 7 is fixed to the lower end of the connecting rod 6. The piston lifting drive device is accommodated in the cavity formed between the inner wall of the outer cylinder body 1 and the outer wall of the inner cylinder body 2, and the piston lifting drive device is connected to the connecting plate 7 and drives its lifting movement. The inner cylinder body 2 is designed as a cylindrical structure with openings at both ends, and the piston lifting drive device is arranged in the air gap between the inner cylinder body 2 and the outer cylinder body 1, which saves the internal space of the inner cylinder body 2 and effectively reduces the height of the inner cylinder body 2. The piston 3 and the inner cylinder are both assembled and driven based on the fixed outer cylinder body 1, which is conducive to improving the movement accuracy of the inner cylinder and the piston 3.

[0024] The inner wall of the outer cylinder body 1 is also fixed with a piston lifting guide rail 8 and an inner cylinder lifting guide rail 9. The connecting plate 7 and the outer wall of the inner cylinder body 2 are respectively fixed in the circumferential direction and can slide in the axial direction on the piston lifting guide rail 8 and the inner cylinder lifting guide rail 9. The piston 3 and the inner cylinder are both guided by the outer cylinder, and the guide base is single, and the accuracy is easy to control.

[0025] Each of the piston lift drive device, piston lift guide rail 8, inner cylinder lift drive device, and inner cylinder lift guide rail 9 is provided in pairs. The two piston lift drive devices 3 and the two piston lift guide rails 8 are symmetrically distributed within the interior of two opposite sides of the outer cylinder body 1, while the two inner cylinder lift drive devices and the two inner cylinder lift guide rails 9 are symmetrically distributed within the interior of the other two opposite sides of the outer cylinder body 1. One piston lift drive device 3 and one piston lift guide rail 8 form a pair, and one inner cylinder lift drive device and one inner cylinder lift guide rail 9 form a pair. These two symmetrical arrangements facilitate improved motion accuracy of the piston 3 and inner cylinder body 2, ensuring smooth lifting motion.

[0026] The cross-section of the inner cylinder body 2 is a square structure, and the outer cylinder body 1 includes a cylinder barrel 16, a cylinder head 17 and a cylinder bottom 18. The cylinder head 17 and the cylinder bottom 18 are respectively fixedly mounted on the upper and lower ends of the cylinder barrel 16. The cylinder head 17 includes a square frame-shaped main body matching the outer side wall of the inner cylinder body 2 and a baffle located on the outer side surface of the lower end of the square frame-shaped main body. The baffle extends radially outward from the outer side wall of the square frame-shaped main body. The cylinder barrel 16 of the outer cylinder body 1 is a cylindrical body with a cross-section consistent with the overall structural shape of the square frame-shaped main body and the baffle of the cylinder head 17. The cylinder bottom 18 is a flat plate structure consistent with the cross-sectional shape of the cylinder barrel 16. The baffle can be rectangular or semicircular, etc. The baffles are preferably symmetrically distributed on the four sides of the square frame-shaped main body of the cylinder cover 17. The outer cylinder body 1 is made into a split structure for convenience in processing and manufacturing. In addition to the square cylinder structure, the inner cylinder body 2 and the outer cylinder body 1 can also adopt a circular cylinder structure. The combination of the inner cylinder body 2 and the outer cylinder body 1 can be a square cylinder structure with a cylinder structure, a circular cylinder structure with a circular cylinder structure, a square cylinder structure with a circular cylinder structure, or a circular cylinder structure with a cylinder structure. The shapes of the cross sections of the inner cylinder body 2 and the outer cylinder body 1 can be the same or different, and can be any shape, as long as they can achieve mutual telescopic movement.

[0027] The piston lifting drive device includes a first servo motor 10 and a first screw 11. The first servo motor 10 is fixedly mounted on the outer cylinder body 1. The first screw 11 is axially fixed and circumferentially rotatable within the cavity formed between the outer cylinder body 1 and the inner cylinder body 2. The first servo motor 10 drives the first screw 11 to rotate, and the first screw 11 is movably threadedly connected to the connecting plate 7. The use of a servo motor to drive the screw to rotate, thereby driving the connecting plate 7 to move up and down, thereby driving the piston 3. This structure is simple and convenient for inching. Other drive methods, such as a hydraulic cylinder, can also be used.

[0028] The inner cylinder drive device includes a second servo motor 12, a second screw rod 13, and a nut sleeve 14. An outer lug plate 15 is fixedly provided on the outer side wall of the inner cylinder body 2. The second screw rod 13 is fixedly mounted on the outer lug plate 15 on the outer side of the inner cylinder body 2. The axial direction of the second screw rod 13 is parallel to the axial direction of the inner cylinder body 2. The nut sleeve 14 is mounted on the inner side wall of the outer cylinder body 1 so as to be rotatable in the circumferential direction and axially fixed. The nut sleeve 14 is movably threaded onto the outer side of the second screw rod 13. The second servo motor 12 is fixedly mounted on the outer cylinder body 1 and drives the nut sleeve 14 to rotate. The outer lug plate 15 is formed on the outer side of the inner cylinder to drive the inner cylinder. The outer lug plates 15 are preferably distributed in an axially symmetrical manner on the outer side wall of the inner cylinder body 2.

[0029] An intermediate cylinder and an intermediate cylinder driving device are also provided. At least one intermediate cylinder is stopped in the circumferential direction from the inside to the outside and can slide relatively in the axial direction to form an intermediate cylinder group. The intermediate cylinder group is inserted between the outer cylinder 1 and the inner cylinder 2. The intermediate cylinder driving device drives the intermediate cylinder to move up and down.

[0030] When using the telescopic cylinder for laser scanning and forming, follow the steps below:

[0031] Step 1: Lift the inner cylinder 2 and seal it with the bottom surface of the scanning plane;

[0032] Step 2: Raise the piston 3 to make the bottom plate 4 flush with the bottom surface of the scanning plane 19;

[0033] Step 3: The forming base plate 4 is gradually lowered to realize layer-by-layer scanning of the laser beam 20. When the forming base plate 4 is lowered to the lowest point, the forming process is completed;

[0034] Step 4: The inner cylinder drops to the lowest point;

[0035] Step 5: Adjust the height of the forming base plate 4 so that the socket 5 on it is at the same height as the fork of the forklift;

[0036] Step 6: Use a forklift to pick up the forming base plate 4 and the formed parts thereon to achieve material removal.

Claims

1. An inner and outer cylinder structure using laser powder melting forming technology, characterized by: The invention comprises an outer cylinder (1), an inner cylinder (2), a piston (3), a piston lifting drive device and an inner cylinder lifting drive device, wherein the upper ends of the outer cylinder and the inner cylinder form an opening structure, the inner cylinder is inserted into the outer cylinder so as to be stopped in the circumferential direction and slidable in the axial direction, the inner cylinder can extend out of the outer cylinder to a set length through the opening structure at the upper end of the outer cylinder, the piston is inserted into the inner cylinder so as to be stopped in the circumferential direction and slidable in the axial direction, the upper end surface of the piston forms a molding surface, the piston lifting drive device drives the piston to move up and down in the inner cylinder, the inner cylinder lifting drive device drives the inner cylinder to move up and down in the outer cylinder, the upper end opening of the outer cylinder forms a contraction structure for radial contraction The outer wall of the inner cylinder body is dynamically sealed with the inner wall of the upper opening of the outer cylinder body through a seal, and the inner cylinder driving device is accommodated in the cavity formed between the inner wall of the outer cylinder body and the outer wall of the inner cylinder body. The outer cylinder body is designed to be a necked structure, and the inner cylinder body is radially positioned by the necked structure. A cavity for accommodating the driving device is formed between the inner cylinder body and the outer cylinder body, so that the driving device does not rely on the frame of the SLM equipment. The telescopic cylinder is separated from the frame, and independent inch motion and full-stroke displacement tests, long-term offline heating temperature tests, and room temperature and high-temperature powder and air tightness tests can be realized offline, avoiding testing on the frame and affecting other components of the SLM equipment.

2. The inner and outer cylinder structure of the laser powder melting forming technology according to claim 1 is characterized in that: The upper end surface of the piston is covered with a formed bottom plate (4), and the formed bottom plate can be completely extended to the outside of the inner cylinder opening structure, and a socket (5) for inserting a forklift fork is provided on the side wall of the formed bottom plate.

3. The inner and outer cylinder structure of the laser powder melting forming technology according to claim 1 is characterized by: The inner cylinder body is a straight cylindrical structure with openings at both ends. A connecting rod (6) is fixedly provided at the lower end of the piston. The lower end of the connecting rod extends outward from the opening at the lower end of the inner cylinder body. A connecting plate (7) is fixedly provided at the lower end of the connecting rod. The piston lifting drive device is accommodated in a cavity formed between the inner side wall of the outer cylinder body and the outer side wall of the inner cylinder body. The piston lifting drive device is connected to the connecting plate and drives its lifting movement.

4. The inner and outer cylinder structure of the laser powder melting forming technology according to claim 3 is characterized by: A piston lifting guide rail (8) and an inner cylinder lifting guide rail (9) are fixedly provided on the inner side wall of the outer cylinder body, and the connecting plate and the outer side wall of the inner cylinder body are respectively fixed in the circumferential direction and can slide in the axial direction on the piston lifting guide rail and the inner cylinder lifting guide rail.

5. The inner and outer cylinder structure of the laser powder melting forming technology according to claim 4 is characterized by: There are two piston lifting drive devices, piston lifting guide rails, inner cylinder lifting drive devices and inner cylinder lifting guide rails. The two piston lifting drive devices and the two piston lifting guide rails are symmetrically distributed inside the two opposite sides of the outer cylinder body, and the two inner cylinder lifting drive devices and the two inner cylinder lifting guide rails are symmetrically distributed inside the other two opposite sides of the outer cylinder body.

6. The inner and outer cylinder structure of the laser powder melting forming technology according to claim 3 is characterized by: The cross section of the inner cylinder body is a square structure, and the outer cylinder body includes a cylinder barrel (16), a cylinder cover (17) and a cylinder bottom (18), wherein the cylinder cover and the cylinder bottom are fixedly mounted on the upper and lower ends of the cylinder barrel respectively, and the cylinder cover includes a square frame-shaped main body matching the outer side wall of the inner cylinder body and a baffle located on the outer side surface of the lower end of the square frame-shaped main body, wherein the baffle extends radially outward from the outer side wall of the square frame-shaped main body, and the cylinder barrel of the outer cylinder body is a cylindrical body with a cross section consistent with the overall structural shape formed by splicing the square frame-shaped main body and the baffle of the cylinder cover, and the cylinder bottom is a flat plate structure consistent with the cross section shape of the cylinder barrel.

7. The inner and outer cylinder structure of the laser powder melting forming technology according to claim 3 is characterized by: The piston lifting drive device comprises a first servo motor (10) and a first screw (11), wherein the first servo motor is fixedly mounted on the outer cylinder body, and the first screw is axially fixed and circumferentially rotatable and mounted in a cavity formed between the outer cylinder body and the inner cylinder body, wherein the first servo motor drives the first screw to rotate, and the first screw is movably screwed to the connecting plate.

8. The inner and outer cylinder structure of the laser powder melting forming technology according to claim 1 is characterized by: The inner cylinder driving device comprises a second servo motor (12), a second screw rod (13) and a nut sleeve (14); an outer lug plate (15) is fixedly provided on the outer side wall of the inner cylinder body; the second screw rod is fixedly mounted on the outer lug plate on the outer side of the inner cylinder body; the axial direction of the second screw rod is parallel to the axial direction of the inner cylinder body; the nut sleeve is mounted on the inner side wall of the outer cylinder body so as to be rotatable in the circumferential direction and axially fixed; the nut sleeve is movably screwed to the outer side of the second screw rod; the second servo motor is fixedly mounted on the outer cylinder body; and the second servo motor drives the nut sleeve to rotate.

9. The inner and outer cylinder structure of the laser powder melting forming technology according to claim 1 is characterized in that: An intermediate cylinder body and an intermediate cylinder body driving device are also provided. At least one intermediate cylinder body is stopped in the circumferential direction from the inside to the outside and can slide relatively in the axial direction to form an intermediate cylinder body group. The intermediate cylinder body group is inserted between the outer cylinder body and the inner cylinder body. The intermediate cylinder body driving device drives the intermediate cylinder body to move up and down.

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