A variable spot additive manufacturing apparatus for mold manufacturing

Abstract

The application discloses a variable light spot additive manufacturing equipment for mold manufacturing, which comprises a horizontally arranged metal additive manufacturing equipment, a laser printing device is arranged at the moving end of the metal additive manufacturing equipment, and a lens cavity is arranged in the laser printing device; a door plate is arranged on one side of the laser printing device; a variable light spot assembly is arranged in the lens cavity; a lower protective mirror assembly is arranged below the variable light spot assembly; an air cooling assembly is arranged on one side of the lower protective mirror assembly; a lens dust cleaning and collecting device is arranged at the bottom of the lower protective mirror assembly; and a heat insulation pad is arranged at the bottom of the lens cavity. The application can effectively cool the lower protective mirror during the printing process of metal 3D laser, avoids the phenomenon of thermal drift, and cleans and collects the micro dust adhered to the lower protective mirror in the gap of printing and trimming, so that the lower protective mirror is kept clean all the time, and the forming precision is ensured.

Description

Technical Field

[0001] This invention relates to the field of metal additive manufacturing equipment technology, and more particularly to a variable spot additive manufacturing equipment for mold making. Background Technology

[0002] Traditional fastener molds are manufactured using cold forging, but this method is limited by forging processes and cutting tools, making it difficult to achieve complex cavities, irregular flow channels, and concave undercut structures. This limitation restricts its application to the production of fastener molds with complex internal structures. To address these issues, metal additive manufacturing (metal 3D printing) offers a better solution for producing and processing fastener molds with complex internal structures. Traditional cold forging requires material preparation, forging, rough or fine machining, heat treatment, polishing, and assembly, taking weeks to months. Metal additive manufacturing, on the other hand, transforms a 3D model into a finished product in just hours to days, eliminating many steps, resulting in a shorter production cycle and lower costs. Therefore, metal additive manufacturing is currently the preferred solution for fastener mold production, offering advantages such as design freedom, rapid delivery, low cost, and flexible customization. It is particularly suitable for new product development, small-batch customization, irregular bolts, and rapid trial production in the fastener industry. The most crucial component in metal additive manufacturing equipment is the variable spot assembly within the laser printhead, which allows for adjustment of the laser spot shape. This variable spot acts as the "high-temperature heat source" for melting metal powder. The size, shape, and energy density of the spot directly determine the precision, efficiency, and quality of the mold printing: Small spots are responsible for shaping fine details such as sharp corners, conformal cooling channels, and precise contours, ensuring dimensional accuracy; large spots are responsible for rapidly filling large areas of the mold matrix, improving printing efficiency; special spot shapes (ring-shaped, flat-topped) optimize molten pool stability and reduce... Fewer pores and spatter defects improve mold density; however, the shape change of the light spot depends on the change of the spacing between multiple sets of lenses to achieve the switching of the light spot shape. The lower protective lens, which is located at the bottom, is closest to the laser nozzle and the light outlet, and therefore has the following problems: First, the ultra-fine metal dust and spatter particles generated by metal printing can seep into the printing chamber from the gaps in the light outlet and accumulate on the inner side of the lower protective lens over a long period of time, weakening the laser energy and affecting the forming accuracy; Second, the high heat of the laser is conducted to the lower protective lens, which can easily cause the lens to thermally drift and the light spot to deform. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide a variable spot additive manufacturing equipment for mold making. During the metal 3D laser printing process, this invention can effectively cool down the lower protective mirror to avoid thermal drift. In addition, during the printing trimming interval, the micro dust adhering to the lower protective mirror is cleaned and collected to keep it clean at all times, so as to ensure the molding accuracy.

[0004] This invention is achieved through the following technical solution: This invention discloses a variable spot additive manufacturing equipment for mold making, including a horizontally arranged metal additive manufacturing equipment. The moving end of the metal additive manufacturing equipment is equipped with a laser printing device. The laser printing device has a lens cavity inside, which is located directly above the laser nozzle at the bottom of the laser printing device. One side of the laser printing device is equipped with a door panel that can be detachably connected to seal the lens cavity by screws. A variable spot assembly is provided inside the lens cavity. A lower protective lens assembly is provided directly below the variable spot assembly. A wind-cooling assembly is provided on one side of the lower protective lens assembly to cool it. The bottom of the lower protective lens assembly is equipped with a lens dust collection device that can clean and collect the micro powder adhering to the bottom of the lower protective lens assembly. A heat insulation pad is provided at the bottom of the lens cavity.

[0005] Furthermore, the variable spot assembly includes an upper protective lens that is detachably slidably connected to the upper part of the lens cavity, a collimating lens group that is detachably slidably connected below the upper protective lens, a middle protective lens that is detachably slidably connected below the collimating lens group, and a focusing lens group that is detachably slidably connected below the middle protective lens.

[0006] Furthermore, the lens ends of the upper protective lens, collimating lens group, focusing lens group, and middle protective lens are on the same horizontal line in the vertical direction, and the collimating lens group and focusing lens group are provided with lead screw slides that can control the up and down movement of the lens ends of the collimating lens group and focusing lens group.

[0007] Furthermore, the lower protective lens assembly includes a detachable sliding frame slidably connected to the lower part of the lens cavity. The sliding frame is located directly below the middle protective lens. The middle part of the sliding frame is through-type and the lower protective lens is horizontally embedded at the through-type. The bottom surface of the lower protective lens is flush with the bottom of the sliding frame.

[0008] Furthermore, the air-cooling assembly includes an annular mounting groove inside the sliding frame. An air-cooling pipe is embedded inside the mounting groove, and the inner side of the air-cooling pipe is attached to the outer side of the lower protective mirror. An air inlet pipe and an air outlet pipe are respectively connected to both ends of the air-cooling pipe. The air inlet pipe and the air outlet pipe are embedded inside the sliding frame. An air supply pipe and an air outlet pipe are respectively detachably inserted at one end of the air inlet pipe and the air outlet pipe. The other end of the air supply pipe's air outlet pipe is located outside the laser printing device and is externally connected to the air outlet and air inlet of an air pump.

[0009] Furthermore, the lens cleaning and collection device includes a drive assembly located at the bottom of the lens cavity. The drive ends on both sides of the top of the drive assembly are respectively provided with a first cleaning assembly and a second cleaning assembly. The drive assembly can drive the first cleaning assembly and the second cleaning assembly to move synchronously toward the opposite side or the opposite side.

[0010] Furthermore, the drive assembly includes a base plate located at the bottom of the lens cavity. One side of the top of the base plate is connected to the bottom of the sliding frame. A dual-axis motor is provided on one side of the top of the base plate. A drive screw is provided on each of the two output ends of the dual-axis motor. The threads on the two drive screws rotate in opposite directions, and the other ends of the drive screws are rotatably connected through a mounting bracket. A limiting rod is horizontally provided on the other side of the top of the base plate. A first sliding block is threaded to one end of each of the two drive screws, and two second sliding blocks are slidably connected to both ends of the limiting rod.

[0011] Furthermore, the first dust removal assembly includes a first sliding box connected to one of the first sliding blocks and the second sliding block on each side. The top of the first sliding box is attached to the bottom of the sliding frame. An air guide groove is provided inside the first sliding box. The air guide groove is inclined and the end near the lower protective mirror is higher than the end away from the lower protective mirror. The top of the first sliding box near the lower protective mirror is provided with a first dust removal groove with an open top. One end of the first dust removal groove is connected to the higher end of the air guide groove.

[0012] Furthermore, a ventilation groove is provided on the side of the top of the first sliding box away from the lower protective mirror, and an air outlet pipe is connected to one end of the bottom of the air inlet pipe. The bottom of the air outlet pipe passes through the sliding frame and is flush with the bottom of the sliding frame. The ventilation groove is connected to the air guide groove. When the first sliding box is away from the lower protective mirror, the top of the first sliding box is closed to the bottom of the air outlet pipe. The diameter of the ventilation groove is larger than the diameter of the air outlet pipe.

[0013] Furthermore, the second dust removal assembly includes a second sliding box connected to a first sliding block and a second sliding block on each side. The top of the second sliding box is provided with a second dust removal groove with an open top on the side near the lower protective mirror. When the second dust removal groove and the first dust removal groove are combined, they can cover the outer side of the bottom surface of the lower protective mirror to form a dust removal chamber. A dust collection chamber is provided on one side inside the second sliding box, and an air outlet is provided on one side of the dust collection chamber. The dust collection chamber and the second dust removal groove are connected by an inclined guide groove. A sealing door that closes the dust collection chamber is detachably connected to the side of the second sliding box away from the first sliding box.

[0014] The present invention has the following advantages: (1) In this invention, while the laser printing device is working, the air-cooling component can provide cooling airflow around the outer side of the lower protective mirror, target and remove the residual heat of the lower protective mirror, control the lens temperature difference within ±1.5℃, completely solve the problem of spot drift caused by laser heating, and ensure the spot adjustment accuracy without strong airflow interfering with powder bed formation. During the printing trimming interval, the first dust removal component and the second dust removal component are connected to each other by the drive component, forming a dust removal cavity that fully covers the bottom surface of the lower protective mirror where dust is easily adhered, and performing all-round air blowing dust removal work on the bottom surface of the lower protective mirror without dead angles, and simultaneously collecting the blown-down dust to avoid secondary pollution. This realizes that during the printing trimming interval, the micro dust adhering to the lower protective mirror is cleaned and collected, keeping it clean at all times to ensure the forming accuracy.

[0015] (2) In this invention, the upper protective mirror is located at the upstream end of the laser printing device, close to the laser inlet. Its core function is to protect the collimating lens group, isolate it from dust and moisture that may seep in from upstream, and prevent the collimating lens from being worn or contaminated. The middle protective mirror is located between the collimating lens group and the focusing lens group. It is the core protective lens, which isolates the dust and laser reflection spatter between the collimating lens group and the focusing lens group, while not affecting the transmission of the parallel laser beam, ensuring that the laser energy is lossless and providing a stable working environment for the focusing lens group. The lower protective mirror is located at the downstream end of the laser printing device. Its core function is to isolate the ultrafine smoke and metal spatter in the forming chamber and protect the focusing lens group from contamination. By finely adjusting the positions of the focusing lens group and the collimating lens group, the position of the laser focal point is changed, thereby adjusting the diameter of the light spot at the light outlet. The closer the focusing lens is to the powder bed, the smaller the light spot, and the farther away it is, the larger the light spot, thus realizing the adjustable light spot operation. Attached Figure Description

[0016] Figure 1 This is a three-dimensional structural diagram of the present invention; Figure 2 This is a three-dimensional structural diagram of the laser printing device in this invention; Figure 3 This is a partial structural schematic diagram of the laser printing device in this invention; Figure 4 This is a partial side sectional view of the laser printing device in this invention; Figure 5 This is a three-dimensional structural diagram of the variable spot component and the lower protective mirror component in this invention; Figure 6 This is a partial side sectional view of the laser printing device, air-cooling assembly, and lens dust collection device in this invention; Figure 7 This is a three-dimensional structural diagram of the lower protective lens assembly, the air-cooling assembly, and the lens dust collection device in this invention. Figure 8This is a three-dimensional structural diagram of the lens dust collection device in this invention; Figure 9 This is a three-dimensional structural diagram of the lower protective mirror assembly in this invention; Figure 10 This is a top sectional view of the lower protective mirror assembly and the air-cooling assembly in this invention; Figure 11 This is a first-state side sectional view of the lower protective mirror assembly, the air-cooling assembly, the first dust removal assembly, and the second dust removal assembly in this invention. Figure 12 This is a second-state side sectional view of the lower protective mirror assembly, air-cooling assembly, first dust removal assembly, and second dust removal assembly in this invention; Figure 13 This is a partial structural schematic diagram of the lower protective lens assembly, the air-cooling assembly, and the lens cleaning and collection device in this invention; Figure 14 This is a three-dimensional structural diagram of the lens dust collection device and heat insulation pad in this invention; Figure 15 This is a top sectional view of the first sliding box and the second sliding box in this invention.

[0017] In the diagram: 1. Metal additive manufacturing equipment; 2. Laser printing device; 3. Lens cavity; 4. Door panel; 5. Variable spot assembly; 51. Upper protective lens; 52. Collimating lens group; 53. Middle protective lens; 54. Focusing lens group; 6. Lower protective lens assembly; 61. Sliding frame; 62. Lower protective lens; 7. Air cooling assembly; 71. Mounting slot; 72. Air cooling duct; 73. Air inlet duct; 74. Air outlet duct; 75. Air supply duct; 76. Air outlet duct; 8. Lens cleaning and dust collection device; 81. Drive assembly; 811 812. Base plate; 813. Dual-axis motor; 814. Drive screw; 815. Mounting bracket; 816. Limiting rod; 817. First sliding block; 818. Second sliding block; 82. First dust removal assembly; 821. First sliding box; 822. Air guide channel; 823. First dust removal channel; 824. Ventilation channel; 825. Air outlet pipe; 83. Second dust removal assembly; 831. Second sliding box; 832. Second dust removal channel; 833. Dust collection chamber; 834. Flow guide channel; 835. Sealing door; 9. Heat insulation pad. Detailed Implementation

[0018] The embodiments of the present invention are described in detail below. These embodiments are implemented based on the technical solution of the present invention, and provide detailed implementation methods and specific operation processes. However, the scope of protection of the present invention is not limited to the following embodiments. In the description of the present invention, words such as "front", "rear", "left", and "right" that indicate orientation or positional relationship are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention.

[0019] Example 1

[0020] Example 1 discloses a variable spot additive manufacturing device for mold making, such as Figures 1-15 As shown, the device includes a horizontally arranged metal additive manufacturing equipment 1. A laser printing device 2 is mounted on the moving end of the metal additive manufacturing equipment 1. A lens cavity 3 is located inside the laser printing device 2, directly above the laser nozzle at the bottom of the laser printing device 2. A door panel 4, detachably connected to the laser printing device 2 and sealing the lens cavity 3, is mounted on one side of the laser printing device 2. A variable spot assembly 5 is mounted inside the lens cavity 3, and a lower protective lens assembly 6 is located directly below the variable spot assembly 5. A wind-cooling assembly 7 is located on one side of the lower protective lens assembly 6 to cool it. A lens dust collection device 8 is located at the bottom of the lower protective lens assembly 6 to clean and collect the micro-powder adhering to the bottom of the lower protective lens assembly 6. A heat insulation pad 9 is located at the bottom inside the lens cavity 3.

[0021] Furthermore, in this embodiment, the variable spot assembly 5 includes an upper protective lens 51 that is detachably slidably connected to the upper part of the lens cavity 3, a collimating lens group 52 that is detachably slidably connected below the upper protective lens 51, a middle protective lens 53 that is detachably slidably connected below the collimating lens group 52, and a focusing lens group 54 that is detachably slidably connected below the middle protective lens 53. Furthermore, the lens ends of the upper protective lens 51, collimating lens group 52, focusing lens group 54 and middle protective lens 53 are on the same horizontal line in the vertical direction, and the collimating lens group 52 and focusing lens group 54 are provided with lead screw slides that can control the up and down movement of the lens ends of the collimating lens group 52 and focusing lens group 54. Furthermore, the lower protective lens assembly 6 includes a detachable sliding frame 61 slidably connected to the lower part of the lens cavity 3. The sliding frame 61 is located directly below the middle protective lens 53. The middle part of the sliding frame 61 is through-shaped and the lower protective lens 62 is horizontally embedded at the through-point. The bottom surface of the lower protective lens 62 is flush with the bottom of the sliding frame 61. like Figures 3 to 9As shown, in this embodiment, the upper protective mirror 51 is located at the upstream end inside the laser printing device 2, close to the laser inlet. Its core function is to protect the collimating lens group 52, isolating it from dust and moisture that may seep in from upstream, and preventing wear and contamination of the collimating lens. It does not participate in spot adjustment, but only plays a protective role, ensuring the stable operation of the collimating lens group 52. The collimating lens group 52 consists of 2-3 collimating lenses. Its core function is to calibrate the diverging laser emitted by the laser into a parallel laser beam. The core first step in spot adjustment is to finely adjust the spacing between the lenses in the collimating lens group 52 through the lead screw slide, changing the diameter of the parallel laser beam and laying the foundation for subsequent focusing spot size adjustment. The focusing lens group 54 consists of 1-2 focusing lenses. Its core function is to focus the collimated parallel laser beam into a tiny spot that can be used to melt metal powder. It is the core component for variable spot adjustment, and is achieved through mechanical micro-adjustment. Adjusting the axial position of the focusing lens group 54 changes the position of the laser focal point, thereby adjusting the diameter of the light spot at the output port. The closer the focusing lens is to the powder bed, the smaller the light spot; the farther away, the larger the light spot. The middle protective lens 53 is located between the collimating lens group 52 and the focusing lens group 54. It is the core protective lens, isolating the collimating lens group 52 and the focusing lens group 54 from dust and laser reflection spatter, while not affecting the transmission of the parallel laser beam, ensuring no laser energy loss, and providing a stable working environment for the focusing lens group 54. The lower protective lens 62 is located inside the downstream output port of the laser printing device 2. Its core function is to isolate the ultrafine dust and metal spatter in the forming chamber, protecting the focusing lens group 54 from contamination. At the same time, it allows the focused laser to penetrate without changing the light spot size and energy distribution. It is the last protective barrier for light spot adjustment and is also the part in all the lens groups most prone to dust accumulation. The upper protective lens 51, collimating lens group 52, middle protective lens 53, focusing lens group 54 and lower protective lens 62 are all detachably installed inside the lens cavity 3. When it is necessary to maintain or replace the above lens group components, simply unscrew the screws and remove the door panel 4 to remove the corresponding lens group components for maintenance or replacement.

[0022] Furthermore, the air-cooling assembly 7 includes an annular mounting groove 71 located inside the sliding frame 61. An air-cooling pipe 72 is embedded inside the mounting groove 71, and the inner side of the air-cooling pipe 72 is attached to the outer side of the lower protective mirror 62. An air inlet pipe 73 and an air outlet pipe 74 are respectively connected to both ends of the air-cooling pipe 72. The air inlet pipe 73 and the air outlet pipe 74 are embedded inside the sliding frame 61. An air supply pipe 75 and an air outlet pipe 76 are respectively detachably inserted into one end of the air inlet pipe 73 and the air outlet pipe 74. The other end of the air outlet pipe 76 of the air supply pipe 75 is located outside the laser printing device 2 and is externally connected to the air outlet and air inlet of the air pump. like Figures 8 to 12As shown, in this embodiment, by arranging a cooling duct 72 around the outside of the lower protective mirror 62, a low-speed and constant-temperature airflow is introduced through an external air pump. The airflow enters through the air inlet duct 73 and flows out through the air outlet duct 74 to achieve airflow circulation. During the operation of the laser printing device 2, the residual heat of the lower protective mirror 62 is targeted and removed, and the temperature difference of the lens is controlled within ±1.5℃. This completely solves the problem of spot drift caused by laser heating, and there is no strong airflow to interfere with powder bed molding, ensuring the accuracy of spot adjustment.

[0023] Furthermore, the lens cleaning and collection device 8 includes a drive assembly 81 located at the bottom of the lens cavity 3. The drive ends on both sides of the top of the drive assembly 81 are respectively provided with a first cleaning assembly 82 and a second cleaning assembly 83. The drive assembly 81 can drive the first cleaning assembly 82 and the second cleaning assembly 83 to move synchronously toward the opposite side or the opposite side. Furthermore, the drive assembly 81 includes a base plate 811 located at the bottom of the lens cavity 3. One side of the top of the base plate 811 is connected to the bottom of the sliding frame 61. A dual-axis motor 812 is provided on one side of the top of the base plate 811. A drive screw 813 is provided on each of the two output ends of the dual-axis motor 812. The threads on the two drive screws 813 rotate in opposite directions, and the other ends of the drive screws 813 are rotatably connected through a mounting bracket 814. A limiting rod 815 is horizontally provided on the other side of the top of the base plate 811. A first sliding block 816 is threadedly connected to one end of each of the two drive screws 813. Two second sliding blocks 817 are slidably connected to both ends of the limiting rod 815. Furthermore, the first dust removal assembly 82 includes a first sliding box 821 connected to one of the first sliding blocks 816 and the second sliding block 817 on both sides respectively. The top of the first sliding box 821 is attached to the bottom of the sliding frame 61. The first sliding box 821 is provided with an air guide groove 822 inside. The air guide groove 822 is inclined and the height of the end near the lower protective mirror 62 is higher than the height of the end away from the lower protective mirror 62. The top of the first sliding box 821 is provided with a first dust removal groove 823 with an open top at the end near the lower protective mirror 62. One end of the first dust removal groove 823 is connected to the higher end of the air guide groove 822. Furthermore, the top of the first sliding box 821 is provided with a ventilation groove 824 on the side away from the lower protective mirror 62. One end of the bottom of the air inlet pipe 73 is connected to an air outlet pipe 825, and the bottom of the air outlet pipe 825 passes through the sliding frame 61 and is flush with the bottom of the sliding frame 61. The ventilation groove 824 is connected to the air guide groove 822. When the first sliding box 821 is away from the lower protective mirror 62, the top of the first sliding box 821 is closed to the bottom of the air outlet pipe 825. The diameter of the ventilation groove 824 is larger than the diameter of the air outlet pipe 825. Furthermore, the second dust removal assembly 83 includes a second sliding box 831 connected to a first sliding block 816 and a second sliding block 817 on both sides respectively. The top of the second sliding box 831 is provided with a second dust removal groove 832 with an open top on the side near the lower protective mirror 62. When the second dust removal groove 832 and the first dust removal groove 823 are combined, they can cover the outer side of the bottom surface of the lower protective mirror 62 to form a dust removal chamber. A dust collection chamber 833 is provided on one side inside the second sliding box 831. An air outlet is provided on one side of the dust collection chamber 833. The dust collection chamber 833 and the second dust removal groove 832 are connected by an inclined guide groove 834. A sealing door 835 that closes the dust collection chamber 833 is detachably connected to the side of the second sliding box 831 away from the first sliding box 821. like Figures 11 to 15 As shown, in this embodiment, in the initial state, the first sliding box 821 and the second sliding box 831 are far apart to avoid obstructing the bottom surface of the lower protective mirror 62. The top of the first sliding box 821 also obstructs the air outlet pipe 825 at the bottom of the air inlet pipe 73, preventing airflow from overflowing from the air inlet pipe 73. During the printing and trimming intervals, the bottom surface of the lower protective mirror 62 can be cleaned using the lens cleaning and collection device 8. First, the dual-axis motor 812 is controlled to operate, and the two drive screws 813 rotate, causing the first sliding box 821 and the second sliding box 831 to move synchronously towards the lower protective mirror 62 until they are fully aligned. At this time, the cleaning chamber formed by the first cleaning groove 823 and the second cleaning groove 832 completely covers the bottom of the lower protective mirror 62. The ventilation groove 824 at the top of the first sliding box 821 is connected to the air outlet pipe 825. A portion of the airflow flowing inside the air inlet pipe 73 will enter the first cleaning groove 825 through the air outlet pipe 825 and the ventilation groove 824. Inside the 23, the airflow is guided by the air guide groove 822 and blown towards the bottom surface of the lower protective mirror 62. Finally, it flows into the dust collection chamber 833 through the second dust cleaning groove 832 and the guide groove 834. During this process, the metal dust adhering to the bottom surface of the lower protective mirror 62 will enter the dust collection chamber 833 with the airflow and be collected. Until the metal dust adhering to the lower protective mirror 62 is completely blown away and collected, the first sliding box 821 and the second sliding box 831 are controlled to move away from each other, and the bottom of the air outlet pipe 825 is sealed again. After the printing work is completed, the lens dust cleaning and collection device 8 can be taken out to the outside of the laser printing device 2. The sealing door 835 on the side of the second sliding box 831 can be removed to take out the metal dust collected in the dust collection chamber 833 for subsequent continuous collection. This device realizes the cleaning and collection of micro dust adhering to the lower protective mirror 62 during the printing and trimming interval, so that it is always clean and ensures the molding accuracy.

[0024] In this embodiment, during operation: by finely adjusting the positions of the focusing lens group 54 and the collimating lens group 52, the position of the laser focusing point is changed, thereby adjusting the diameter of the light spot at the output port. The closer the focusing lens is to the powder bed, the smaller the light spot; the farther away the focusing lens is, the larger the light spot, thus achieving variable light spot adjustment. While the laser printing device 2 is working, the air-cooling component 7 can provide cooling airflow around the outside of the lower protective mirror 62, targeting and removing the residual heat of the lower protective mirror 62, controlling the lens temperature difference within ±1.5℃, completely solving the problem of light spot drift caused by laser heating, and eliminating strong airflow interference with the powder bed. Forming ensures the precision of light spot adjustment; during the printing and trimming interval, the first dust removal component 82 and the second dust removal component 83 are controlled by the drive component 81 to connect with each other, forming a dust removal chamber that fully covers the bottom surface of the lower protective mirror 62 where dust easily adheres, and performing all-round, no-dead-angle air blowing dust removal work on the bottom surface of the lower protective mirror 62, while simultaneously collecting the blown-down dust to avoid secondary pollution. This achieves the cleaning and collection of micro dust adhering to the lower protective mirror 62 during the printing and trimming interval, keeping it clean at all times to ensure the forming precision.

[0025] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A variable spot additive manufacturing device for mold making, characterized in that, The equipment includes a horizontally arranged metal additive manufacturing device (1), the movable end of which is provided with a laser printing device (2), and the inside of the laser printing device (2) is provided with a lens cavity (3), which is located directly above the laser nozzle at the bottom of the laser printing device (2). The laser printing device (2) has a door panel (4) on one side that is detachably connected to the lens cavity (3) by screws. The lens cavity (3) is provided with a variable spot assembly (5), and a lower protective lens assembly (6) is provided directly below the variable spot assembly (5). A wind-cooling assembly (7) is provided on one side of the lower protective lens assembly (6) to cool the lower protective lens assembly (6). The bottom of the lower protective lens assembly (6) is provided with a lens cleaning and collection device (8) that can clean and collect the micro powder adhering to the bottom of the lower protective lens assembly (6), and the bottom of the lens cavity (3) is provided with a heat insulation pad (9).

2. The variable spot additive manufacturing equipment for mold making as described in claim 1, characterized in that, The variable spot assembly (5) includes an upper protective lens (51) detachably slidably connected to the upper part of the lens cavity (3), a collimating lens group (52) detachably slidably connected below the upper protective lens (51), a middle protective lens (53) detachably slidably connected below the collimating lens group (52), and a focusing lens group (54) detachably slidably connected below the middle protective lens (53).

3. The variable spot additive manufacturing equipment for mold making as described in claim 2, characterized in that, The lens ends of the upper protective lens (51), collimating lens group (52), focusing lens group (54) and middle protective lens (53) are on the same horizontal line in the vertical direction. The collimating lens group (52) and focusing lens group (54) are provided with a screw slide that can control the up and down movement of the lens ends of the collimating lens group (52) and focusing lens group (54).

4. The variable spot additive manufacturing equipment for mold making as described in claim 3, characterized in that, The lower protective lens assembly (6) includes a detachable sliding frame (61) slidably connected to the lower part of the lens cavity (3). The sliding frame (61) is located directly below the middle protective lens (53). The middle part of the sliding frame (61) is through-set and the lower protective lens (62) is horizontally embedded at the through-set. The bottom surface of the lower protective lens (62) is flush with the bottom of the sliding frame (61).

5. The variable spot additive manufacturing equipment for mold making as described in claim 4, characterized in that, The air-cooling assembly (7) includes an annular mounting groove (71) located inside the sliding frame (61). An air-cooling pipe (72) is embedded inside the mounting groove (71), and the inner side of the air-cooling pipe (72) is attached to the outer side of the lower protective mirror (62). An air inlet pipe (73) and an air outlet pipe (74) are respectively connected to both ends of the air-cooling pipe (72). The air inlet pipe (73) and the air outlet pipe (74) are embedded inside the sliding frame (61). An air supply pipe (75) and an air outlet pipe (76) are respectively detachably inserted into one end of the air inlet pipe (73) and the air outlet pipe (74). The other end of the air outlet pipe (76) of the air supply pipe (75) is located outside the laser printing device (2) and is connected to the air outlet and air inlet of the air pump.

6. The variable spot additive manufacturing equipment for mold making as described in claim 5, characterized in that, The lens cleaning and collection device (8) includes a drive assembly (81) located at the bottom of the lens cavity (3). The drive ends on both sides of the top of the drive assembly (81) are respectively provided with a first cleaning assembly (82) and a second cleaning assembly (83). The drive assembly (81) can drive the first cleaning assembly (82) and the second cleaning assembly (83) to move synchronously toward the opposite side or the opposite side.

7. The variable spot additive manufacturing equipment for mold making as described in claim 6, characterized in that, The drive assembly (81) includes a base plate (811) located at the bottom of the lens cavity (3). One side of the top of the base plate (811) is connected to the bottom of the sliding frame (61). A dual-axis motor (812) is provided on one side of the top of the base plate (811). A drive screw (813) is provided on each of the two output ends of the dual-axis motor (812). The threads on the two drive screws (813) rotate in opposite directions, and the other ends of the drive screws (813) are rotatably connected through a mounting bracket (814). A limiting rod (815) is horizontally provided on the other side of the top of the base plate (811). A first sliding block (816) is threadedly connected to one end of each of the two drive screws (813). Two second sliding blocks (817) are slidably connected to both ends of the limiting rod (815).

8. The variable spot additive manufacturing equipment for mold making as described in claim 7, characterized in that, The first dust removal assembly (82) includes a first sliding box (821) connected to one of the first sliding blocks (816) and the second sliding block (817) on both sides respectively. The top of the first sliding box (821) is attached to the bottom of the sliding frame (61). The first sliding box (821) is provided with an air guide groove (822). The air guide groove (822) is inclined and the height of the end near the lower protective mirror (62) is higher than the height of the end away from the lower protective mirror (62). The top of the first sliding box (821) near the lower protective mirror (62) is provided with a first dust removal groove (823) with the top open. One end of the first dust removal groove (823) is connected to the higher end of the air guide groove (822).

9. A variable spot additive manufacturing device for mold making as described in claim 8, characterized in that, The first sliding box (821) has a ventilation groove (824) on the side away from the lower protective mirror (62) at the top. One end of the bottom of the air inlet pipe (73) is connected to an air outlet pipe (825), and the bottom of the air outlet pipe (825) passes through the sliding frame (61) and is flush with the bottom of the sliding frame (61). The ventilation groove (824) is connected to the air guide groove (822). When the first sliding box (821) is away from the lower protective mirror (62), the top of the first sliding box (821) is closed to the bottom of the air outlet pipe (825). The diameter of the ventilation groove (824) is larger than the diameter of the air outlet pipe (825).

10. A variable spot additive manufacturing device for mold making as described in claim 9, characterized in that, The second dust removal assembly (83) includes a second sliding box (831) connected to a first sliding block (816) and a second sliding block (817) on both sides respectively. The top of the second sliding box (831) near the lower protective mirror (62) is provided with a second dust removal groove (832) with an open top. When the second dust removal groove (832) and the first dust removal groove (823) are combined, they can cover the outer side of the bottom surface of the lower protective mirror (62) to form a dust removal chamber. A dust collection chamber (833) is provided on one side inside the second sliding box (831). An air outlet is provided on one side of the dust collection chamber (833). The dust collection chamber (833) and the second dust removal groove (832) are connected by an inclined guide groove (834). A sealing door (835) that closes the dust collection chamber (833) is detachably connected to the side of the second sliding box (831) away from the first sliding box (821).

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