Laser forming technology template equipment and laser forming technology template method

Abstract

The present invention discloses a template device of laser forming technology and a template method of laser forming technology. The template device installs a frame-shaped template component on the forming port at the lower end of the laser forming chamber, and a forming base plate that can be inch-moved and lifted is arranged directly below the forming port of the laser forming chamber. The forming base plate and the template component are sealed and connected by a limiter to form a powder holding space. The laser melting system laser melts and forms the powder in the powder holding space. The template method of laser forming technology is as follows: first, the template component and the sealing ring are installed at the forming port at the lower end of the forming chamber, and the forming base plate is installed on a movable crossbeam or a forming cylinder piston; the forming base plate is moved to an initial position in the template component, and powder is scraped and laser melted to form the workpiece and the accompanying cylinder. Finally, the workpiece and the accompanying cylinder are taken out after being separated from the template component as the forming base plate descends. The present invention saves resources, avoids waste of resources and powder, reduces the difficulty and cost of taking out, and reduces the height of the equipment.

Description

Technical Field

[0001] The present invention relates to a laser melting technology, in particular to a template device and a template method of the laser forming technology. Background Art

[0002] SLM is the most influential 3D metal printing technology within the additive manufacturing (AM) family. Its high precision and strength surpass those of precision wax casting, enabling direct part production. SLM's strength rivals that of forging, while its precision far exceeds that of forging (which produces parts from a blank). However, SLM's plasticity is lower than forging, and as a result, it lags behind forging in fatigue resistance and impact toughness, though still far surpasses investment casting. SLM is the most mature, stable, widespread, and popular AM technology used in industrial production today.

[0003] Existing SLM technology has a fatal weakness: it uses a forming cylinder-piston technology. The forming process begins at the cylinder mouth of the forming cylinder. The laser melts the powder to form a layer. The piston drives the layer down a certain thickness (20-80μm, which is the so-called adaptive movement of the forming cylinder and piston). Then a new layer of powder is spread in the space, melted by the laser again, and welded to the lower layer (the first formed layer) to form a whole. This process repeats thousands of times, with each layer "powdering-melting-welding" at the cylinder mouth to form a whole. SLM forming cylinder system see Figure 1 The forming process of traditional SLM technology has brought a series of problems that have troubled the engineering community.

[0004] 1. The diameter of the forming cylinder is fixed, but the cross-section of the formed part varies in size. It is common to have a large forming cylinder to melt and form very small formed parts, resulting in serious waste of resources and powder. Figure 5 .

[0005] 2. After the molded part is completed, it remains in the forming cylinder, making it difficult to remove. To remove the part, it can be pushed into the forming chamber. Removing it requires either opening the chamber's top (which includes the laser optical system, galvanometers, and other precision instruments) or horizontally ejecting the forming plate along with the part. Both solutions significantly increase the complexity of the equipment, particularly the forming chamber. Furthermore, the height of the molded part must be less than the height of the chamber's inner cavity (vertical focal length), which significantly limits its length.

[0006] To remove the part, there's also the so-called "cylinder-chamber" separation method. This method separates the build cylinder from the build chamber, allowing the cylinder (including the molded part) to be removed. Obviously, for heavy SLM, separating the cylinder from the chamber and performing horizontal movement is not an easy task and significantly increases costs.

[0007] 3. Another problem with the forming cylinder-piston system is the bulky structure of the machine. When the piston moves down a stroke S, the piston rod also moves down a stroke S. Adding the height of the piston drive system and the piston, the total length of the forming cylinder-piston system will reach 2.5 to 3 times S, which greatly increases the height of the equipment. Figure 1 . Summary of the Invention

[0008] In order to make up for the above shortcomings, the present invention provides a template equipment of laser forming technology and a template method of laser forming technology. The template equipment of laser forming technology and the template method of laser forming technology are used for laser forming, which avoids powder waste, facilitates the removal of workpieces, reduces the overall height of the equipment, greatly reduces the forming cost, and improves the forming efficiency.

[0009] The technical solution adopted by the present invention to solve its technical problems is: a template equipment of laser forming technology, including a frame, a laser forming chamber and a laser melting system, the laser forming chamber is fixedly installed on the frame, the laser melting system is installed above the laser forming chamber, and is also provided with a template assembly, a limiter, a forming base plate and an inching lifting drive device. The frame-shaped template assembly can be fixedly installed on the forming opening at the lower end of the laser forming chamber, the forming base plate can be lifted and lowered and is located directly below the forming opening of the laser forming chamber, the inching lifting drive device drives the forming base plate to inch up and down, the upper end of the limiter can be sealed and connected with the inner side of the template assembly, the lower end of the limiter is sealed and positioned with the upper surface of the forming base plate, the height of the limiter can be extended as the forming base plate descends and extends, the limiter and the inner side of the template assembly form a powder containing space, and the laser melting system can perform laser melting forming on the powder material in the powder containing space.

[0010] As a further improvement of the invention, the inch-motion lifting drive device includes an inch-motion control system, a first servo motor, a first reducer, a screw and a movable crossbeam. At least one screw is installed on the frame, and a first drive nut is provided on the movable crossbeam. The first drive nut is movably threaded with each screw. The first servo motor drives each first drive nut to rotate synchronously with the screw through the first reducer. The inch-motion control system controls the start and stop and forward and reverse rotation of the first servo motor. A vertical linear guide is also provided on the frame. The side wall of the movable crossbeam is installed on the linear guide, and the forming base plate is positioned on the movable crossbeam. The driving nut can be axially stopped and circumferentially rotatable and installed on the movable crossbeam, and the screw rod is fixed on the frame, or the screw rod can be axially stopped and circumferentially rotatable and installed on the frame, and the driving nut is fixed on the movable crossbeam. The first servo motor drives each driving nut to rotate or drives the screw rod to rotate through the first reducer. The driving nut is rotatably installed on the movable crossbeam through the bearing, and the screw rod is rotatably installed on the frame through the bearing on the bearing seat. When the screw rod rotates, the first servo motor and the first reducer can be arranged in the molding box or outside the molding box.

[0011] As a further improvement of the invention, a buffer is further provided on the frame, and the lower side of the movable crossbeam is opposite to the buffer. When the movable crossbeam descends, the buffer cushions it to avoid collision.

[0012] As a further improvement of the invention, the inching lifting drive device is a forming cylinder fixedly mounted on the frame, the inner side of the forming cylinder is sealed and connected to the inner side of the template assembly, and the forming base plate is positioned on the piston of the forming cylinder.

[0013] As a further improvement of the invention, the limiting member is a companion tube that is formed synchronously with the workpiece on the forming base plate by the laser melting system. The companion tube is sleeved on the outside of the workpiece and is at the same height as the workpiece. The cross-section of the companion tube is square, circular or a conformal shape that matches the shape of the workpiece.

[0014] As a further improvement of the invention, the circumferential outer surface of the accompanying cylinder is aligned with the outer edge of the forming base plate, and a sealing ring is sealed and fixed at the lower end of the template assembly. The sealing ring is in sealing contact with the circumferential outer surface of at least one of the forming base plate and the accompanying cylinder.

[0015] As a further improvement of the invention, the limiting part includes a telescopic cylinder, a telescopic beam, a second servo motor and a second reducer. The telescopic beam is provided with a second drive nut, which is movably threaded with the screw. The second servo motor drives each second drive nut to rotate synchronously with the screw through the second reducer. The side wall of the telescopic beam is installed on a linear guide rail. The lower end of the telescopic cylinder that can elastically expand and contract in the height direction is sealed and fixedly installed on the upper surface of the movable cross beam. The upper end of the telescopic cylinder is sealed and fixedly installed on the lower surface of the telescopic beam. The mold plate assembly, the telescopic beam and the inner side of the telescopic cylinder and the surface of the forming bottom plate can just enclose a powder containing space that is sealed and connected to the forming chamber.

[0016] As a further improvement of the invention, the limiting member is a cylindrical structure integrally formed on the inner side of the mold plate assembly, and its inner surface is in sealing contact with the outer side wall of the molded base plate.

[0017] As a further improvement of the invention, the mold assembly includes a main mold and a sub-mold. The frame-shaped main mold is fixedly installed on the forming port at the lower end of the laser forming chamber, and the sub-mold can be removably fixed on the main mold. The main mold and the sub-mold are horizontally aligned to form the powder base surface of the equipment. The outer circumference of the forming base plate is completely matched with the inner side wall of the sub-mold. The forming base plate or the upper limit member of the forming base plate can cooperate with the sub-mold to form a powder holding space.

[0018] As a further improvement of the invention, a forming table is provided, which includes a heat insulation plate, a fork plate, a heating plate and a height adjustment plate stacked in sequence from bottom to top. A slot structure is formed on the fork plate for inserting the plug-in plate, and the forming base plate is fixedly installed above the heating plate of the forming table.

[0019] As a further improvement of the invention, a forming hood and a forming cylinder are further provided on the frame, and the forming hood is covered on the outside of the laser forming chamber and the laser melting system. The forming hood is provided with a forming perspective window for observing the laser forming chamber and an upper inspection door for entering the forming hood. The upper end of the forming cylinder is connected with the lower end of the forming hood, and the mold plate assembly, the limit part, the forming base plate and the inch-motion lifting drive device are all covered in the forming cylinder. The forming cylinder is provided with a removal door for removing the workpiece and a lower inspection door for entering the forming cylinder.

[0020] As a further improvement of the invention, at least one powder leakage hole is provided on the forming base plate, and a powder leakage channel is also provided on the frame. One end of the powder leakage channel is connected to the powder leakage hole on the forming plate, and the other end of the powder leakage channel can be connected to the exhaust device. A closing switch is provided on the powder leakage channel.

[0021] A template method using laser forming technology comprises the following steps:

[0022] Step 1: Install the frame-shaped template assembly and the sealing ring at the molding port at the lower end of the molding chamber, and align the upper end surface of the template assembly with the bottom surface of the molding chamber;

[0023] Step 2: Install the forming base plate on the movable crossbeam or the forming cylinder piston;

[0024] Step 3: The movable crossbeam or the piston of the forming cylinder drives the forming base plate to the initial forming position. At this time, there is a height difference between the forming base plate and the bottom surface of the forming chamber for the first powder spreading, and a powder holding space is formed between the forming base plate and the template assembly;

[0025] Step 4: The powder scraping device in the molding chamber is started. The powder scraping device scrapes the powder sent into the molding chamber from the powder feeding box into the powder holding space between the forming base plate and the template assembly. The laser melting system laser melts and forms a layer of workpiece cross-section, and at the same time forms a layer of accompanying tube cross-section on the periphery of the workpiece.

[0026] Step 5: The movable crossbeam or the piston of the forming cylinder drives the forming bottom plate to move downward in an inch motion. The powder scraping device in the forming chamber scrapes the powder into the powder holding space again. The laser melting system then laser melts and forms a layer of workpiece cross-section on the surface of the workpiece. At the same time, it laser melts and forms a layer of accompanying tube cross-section on the surface of the accompanying tube. The laser melting process is repeated in this way to finally form a complete workpiece and an accompanying tube that is sleeved around the periphery of the workpiece and has the same height as the workpiece.

[0027] Step 6: The movable crossbeam or the forming cylinder piston descends to separate the workpiece and the accompanying tube from the template assembly, remove the accompanying tube and the workpiece, and then remove the accompanying tube from the periphery of the workpiece.

[0028] As a further improvement of the invention, a main mold plate of the mold plate assembly is obtained by machining, and the main mold plate is fixedly installed on the inner side of the molding port at the lower end of the molding chamber, and a whole plate is fixedly installed on the main mold plate, and the whole plate is horizontally aligned with the main mold plate and the bottom surface of the molding chamber, and the whole plate completely covers the inner space of the main mold plate, and the middle part of the whole plate is fixedly connected to the movable crossbeam or the forming table on the forming cylinder piston, and then, the whole plate is laser cut by a laser melting system, and the part connected to the main mold plate after cutting becomes a sub-mold plate, and the part fixedly connected to the movable crossbeam or the forming table on the forming cylinder piston becomes a forming bottom plate.

[0029] As a further improvement of the invention, the main mold plate, sub-mold plate and forming base plate of the mold plate assembly are obtained by machining, and the main mold plate is fixedly installed on the inner side of the forming port at the lower end of the molding chamber, the sub-mold plate is fixedly installed on the inner side of the main mold plate, and the forming base plate is installed on the forming table of the movable crossbeam or the forming cylinder piston, wherein the inner contour of the sub-mold plate and the outer contour of the forming base plate are separately processed according to the design, or the outer contour of the forming base plate is processed with the inner contour of the sub-mold plate as the reference, or the inner contour of the sub-mold plate is processed with the outer contour of the forming base plate as the reference.

[0030] The beneficial technical effect of the present invention is: the present invention abandons the forming cylinder structure of the traditional laser forming equipment, and arranges a template assembly on the forming port at the lower end of the laser forming chamber, and seals the template assembly and the forming bottom plate through a limiter to form a powder holding space. The forming plate performs precise inch movement with the inch-motion lifting and lowering drive device to realize layered laser melting forming of the workpiece. The limiter forms a powder holding space in the accompanying cylinder or the telescopic cylinder by adopting a companion cylinder or a telescopic cylinder supported by elastic material, which greatly reduces powder waste. The template assembly is positioned in coordination with the forming port at the lower end of the laser forming chamber through the main template, and the inner diameter is adjusted according to the size of the workpiece through the auxiliary template, and then adapted to the size adjustment of the accompanying cylinder, forming a more adaptable and flexible adjustment method. The invention can process workpieces of different sizes by simply replacing the sub-mold. During processing, the sub-mold and the forming base plate on the movable crossbeam forming table are formed by laser cutting the entire plate, ensuring the matching accuracy between the sub-mold and the forming base plate and avoiding interference between the two. The invention greatly saves resources, avoids waste of resources and powder, improves the convenience of removing the workpiece after forming, reduces the difficulty and cost of removing the workpiece, replaces the piston structure in the forming cylinder with the movable crossbeam and the upper forming table, reduces the distance of the piston extending at the end of the lower stroke, effectively reduces the height of the equipment, breaks through the constraint of the forming cylinder, and is applicable to both large and medium-sized SLM equipment. It has great engineering value and reduces equipment cost and forming processing cost.

[0031] It can be seen that the present invention has the following four major advantages:

[0032] (1) The “form plate-form table” system is completely separated from the drive system, which can expand or reduce the cross-sectional area of ​​the powder holding space, thereby changing the size of the powder, achieving large powder for large parts and small powder for small parts;

[0033] (2) After scanning, the formed part is on the forming base plate, and the door can be opened to fork and pick up the part in situ, creating the premise for large / super-large SLM;

[0034] (3) The whole machine has a compact structure, which is generally only half the volume of the SLM equipment of the forming cylinder-piston system;

[0035] (4) The separation of powder seal and air seal can achieve a higher forming base plate temperature. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 This is a schematic diagram of the principle of workpiece melting and forming in the prior art;

[0037] Figure 2 This is a schematic diagram of the "shape" when forming using existing technology;

[0038] Figure 3 It is a schematic diagram of the “shape” when forming by using the existing technology;

[0039] Figure 4 This is the main view of the state of forming a large workpiece using existing technology;

[0040] Figure 5 This is a cross-sectional view of a forming cylinder when forming a large workpiece using existing technology;

[0041] Figure 6 This is the main view of the state of a small workpiece formed using existing technology;

[0042] Figure 7 A cross-sectional view of a forming cylinder when forming a small workpiece using existing technology;

[0043] Figure 8 This is a front view of the template equipment structure of the present invention in the starting forming state;

[0044] Figure 9 This is a front view of the template equipment structure of the present invention in the final state of forming;

[0045] Figure 10 This is a schematic diagram of the powder holding space structure formed by the first type of template assembly of the present invention;

[0046] Figure 11 for Figure 10 Middle AA section view;

[0047] Figure 12 This is a schematic diagram of the powder holding space structure formed by the second type of template assembly of the present invention;

[0048] Figure 13 This is the principle diagram of the structure of the first type of template assembly and the accompanying tube;

[0049] Figure 14 This is a schematic diagram of the structure of the second type of template assembly and the accompanying tube;

[0050] Figure 15 This is a schematic diagram of the structure of the third type of template assembly and the accompanying tube;

[0051] Figure 16 This is a schematic diagram of the structure of the fourth type of template assembly and the accompanying tube;

[0052] Figure 17 This is a diagram showing the laser cutting state of the auxiliary mold plate and the forming base plate of the present invention;

[0053] Figure 18 Diagram of the starting state of laser melting forming using the present invention;

[0054] Figure 19 The final state diagram of laser melting forming by using the present invention;

[0055] Figure 20 A diagram showing the state of removing a part after laser melting and forming using the present invention;

[0056] Figure 21 Schematic diagram of the telescopic cylinder structure principle;

[0057] Figure 22 This is a diagram of the forming steps using the telescopic cylinder structure bottom discharge method;

[0058] Figure 23 This is a structural principle diagram of the limiter being integrally formed on the template assembly;

[0059] Figure 24 This is a diagram of the forming steps using the upper discharge method with an integrated limiter.

[0060] Laser forming chamber---1 Forming cylinder---2 Piston---3 Piston rod---4

[0061] Forming base plate---5 Scraping base plate---6 Scraping base surface---7

[0062] Scraper---8 Forming the outer wall of the bottom plate ("shape")---9

[0063] Scrape the inner wall of the substrate or the mold - "Mold" --- 10 Powder --- 11

[0064] First melting layer --- 12 Formed part --- 13 Laser beam --- 14

[0065] Frame support surface---15 Forming cylinder bottom---16

[0066] Laser melting system---17 Forming cover---18 Forming cylinder---19

[0067] Upper inspection door---20 Lower inspection door---21 Formed perspective window---22

[0068] Pickup door---23 Movable crossbeam---24 Accompanying cylinder---25

[0069] Forming table---26 Inching control system---27 Screw---28

[0070] Guide rail---29 Cylinder-free constrained forming part layer---30 Main plate---31

[0071] Auxiliary plate---32 Sealing ring---33 Telescopic cylinder---34

[0072] Telescopic beam---35, Height adjustment plate---36 Buffer---37

[0073] Powder leakage channel---38 Support---171 Focusing lens---172

[0074] Galvanometer---173 Bearing seat---39 Frame---40 DETAILED DESCRIPTION

[0075] During the SLM process, a flat surface is required to serve as a reference for the scraper blade's movement. This surface is called the powder spreading base. It is designed with an inner hole that matches the inner diameter of the forming cylinder. The walls of the inner hole serve to limit the powder spreading range and can be considered a model, hence the abbreviation "model." The plate on which the powder spreading (scraping) base surface resides is also called the "model plate." The SLM forming cylinder contains a piston, the top surface of which is used to mount the forming base plate, a flat plate used to weld the formed part and the support structure. Its outer contour precisely matches the inner diameter of the cylinder—the "model." This outer contour is referred to herein as the "shape." The SLM forming process can be explained using the concepts of "model" and "shape."

[0076] The mold and the form prevent leakage of powder and inert gas throughout the forming process, and the two forms cooperate to prevent them from getting stuck when the forming base plate is heated. The form moves with the forming base plate at 20-80μm intervals, forming layers of powder, one after another, melted by the laser focus (corresponding exactly to the slices in the digital model). These layers are welded and stacked together to form a single metal part. This metal part will eventually enter the forming cylinder.

[0077] The above analysis shows that the functions of "type" and "shape" are indispensable in the entire forming process, but is it necessary to use a forming cylinder-piston system to achieve this? In order to avoid the shortcomings of the forming cylinder, this paper proposes the concept and method of the template.

[0078] Example: A template equipment using laser forming technology includes a frame, a laser forming chamber 1 and a laser melting system 17. The laser forming chamber 1 is fixedly mounted on the frame, and the laser melting system 17 is mounted above the laser forming chamber 1. The laser melting system 17 includes a support 171 fixedly mounted above the laser forming chamber, a focusing mirror 172 fixedly mounted on the support, and a galvanometer 173 located above the focusing mirror. It also includes a template assembly, a limiter, a forming base plate 5, and an inching lifting drive device. The frame-shaped template assembly The part can be fixedly installed on the forming port at the lower end of the laser forming chamber 1, and the forming base plate 5 can be raised and lowered and is located directly below the forming port of the laser forming chamber. The inch-motion lifting drive device drives the forming base plate 5 to rise and fall inch by inch. The upper end of the limiter can be sealed and connected with the inner side of the template assembly, and the lower end of the limiter is sealed and positioned with the upper surface of the forming base plate 5. The height of the limiter can be extended as the forming base plate 5 descends and extends. The limiter and the inner side of the template assembly form a powder holding space, and the laser melting system 17 can perform laser melting and forming on the powder material in the powder holding space. By placing a pattern plate assembly at the lower forming opening of the laser forming chamber 1, a powder holding space is formed by the pattern plate assembly, a stopper, and a forming base plate 5. The upper surface of the pattern plate assembly replaces the scraped base surface, serving as the powder spreading (scraping) base. The "form" on the inner side of the forming plate assembly replaces the "form" of the forming cylinder's internal contour. This structure allows the diameter of the powder holding space to be adjusted by varying the inner diameter of the pattern plate assembly (i.e., the "form") and the inner diameter of the stopper, accommodating both large and small parts. This eliminates the problem of using a large cylinder for small tasks, achieving a large cylinder for large tasks and a small cylinder for small tasks. The stopper prevents powder from spilling out. When extended, it secures the powder and prevents it from spilling. When retracted, the formed part remains isolated on the forming base plate 5, making it easy to remove with a forklift. The inching lift drive does not require a cooling system because it is sufficiently distant from the "form" and its thermal expansion is independent of the "form."

[0079] The inch-motion lifting drive device includes an inch-motion control system 27, a first servo motor, a first reducer, a screw rod 28 and a movable crossbeam 24. Several screw rods 28 are installed on the frame with axial stop and circumferential rotation. The movable crossbeam 24 is movably screwed with each screw rod 28. The first servo motor drives each screw rod 28 to rotate synchronously through the first reducer. The inch-motion control system 27 controls the start and stop and forward and reverse rotation of the first servo motor. A vertical linear guide rail is also provided on the frame. The side wall of the movable crossbeam 24 is installed on the linear guide rail, and the forming base plate 5 is positioned on the movable crossbeam 24.

[0080] The first servo motor drives the screw rod 28 to rotate through the first reducer, thereby driving the movable crossbeam 24 to move up and down. The first reducer is preferably a heavy-duty reducer, and a large reduction ratio scheme can be adopted to improve the inch-moving accuracy of the movable crossbeam 24. The screw rods 28 are preferably multiple and evenly distributed around the movable crossbeam 24, such as four screw rods 28 distributed at the four corners of the movable crossbeam 24, etc. A nut is fixedly embedded on the movable crossbeam 24 and screwed to the screw rod 28. The movable crossbeam 24 is guided by a linear guide rail to ensure its vertical inch-moving movement. A buffer 37 is preferably provided under the movable crossbeam 24 on the frame to avoid the movable crossbeam After 24 reaches the bottom, it collides with the frame. This application abandons the forming cylinder of the traditional laser forming equipment and replaces it with a template assembly. The piston in the forming cylinder is abandoned and replaced with a forming plate installed on the movable crossbeam 24. The limiter seals the template assembly and the forming plate to form a powder holding space. The forming plate moves precisely with the movable crossbeam 24 (20-80 microns / time) and is repeated tens of thousands of times during the forming process. The 20-80 micron inch movement is adapted to the layering (slicing) of the forming process to ensure the melting / sintering of the slices and the precise "accumulation" to form. The movable crossbeam 24 is driven by the inch drive system to complete the inch movement;

[0081] Due to the characteristics of piston drive in traditional SLM machines, the piston has to extend a stroke distance at the end of the downstroke. Therefore, the total length of its piston-driver-piston rod system is one stroke longer than the total length of this design. This structure replaces the forming cylinder, breaking through the limitations of the forming cylinder. It is applicable to both large and medium-sized SLM equipment and has great engineering value.

[0082] The inching lifting drive device is a forming cylinder fixedly mounted on the frame, the inner side of the forming cylinder is sealed and connected to the inner side of the template assembly, and the forming base plate 5 is positioned on the piston of the forming cylinder. Waste can be avoided by matching the forming cylinder with the template assembly.

[0083] The limiting part is a companion tube 25 formed synchronously with the workpiece on the forming base plate 5 by the laser melting system 17. The companion tube 25 is sleeved on the outside of the workpiece and is at the same height as the workpiece. The cross section of the companion tube 25 is square, circular or a shape that matches the shape of the workpiece. During the laser melting forming process of the workpiece, a companion tube 25 is formed synchronously by laser melting on the outside of the workpiece. The companion tube 25 increases synchronously with the increase in the height of the workpiece. The companion tube 25 is wrapped around the periphery of the workpiece, and its lower end is produced on the forming plate, and its upper end is connected to the inner wall of the template assembly. Starting from the second powder spreading, a powder holding space is formed on the inner side of the companion tube 25 for holding powder. Since it can be adjusted according to the outer diameter of the workpiece, the gap between it and the workpiece is small. During the laser melting forming process, there is less excess powder in the companion tube 25, which saves powder and avoids powder waste. The cross section of the companion tube 25 can be adjusted according to the outer diameter of the workpiece. The shape can be adaptively selected. For square workpieces, a square companion tube 25 can be selected. For round or nearly round workpieces, a round companion tube 25 or a conformal companion tube 25 can be selected. You can also select an elliptical companion tube 25 or other companion tubes 25 that are close to the workpiece shape according to the workpiece shape to save powder. In addition to the companion tube 25, it can also be a cylindrical part made of other elastically stretchable materials, the upper and lower ends of which are respectively sealed with the mold plate assembly and the forming base plate 5. This is an equivalent replacement structure that a person skilled in the art can easily think of based on the technical solution of this patent, and it falls within the scope of protection of this patent.

[0084] The outer circumferential surface of the accompanying tube 25 is aligned with the outer edge of the forming base plate 5, and a sealing ring 33 is sealed and fixed at the lower end of the template assembly. The sealing ring 33 is in sealing contact with the outer circumferential surface of at least one of the forming base plate 5 and the accompanying tube 25. During the first laser melting forming, the template assembly is sleeved on the outer side of the forming base plate 5, and the two together form a powder holding space. After the first forming, the forming base plate 5 is lowered by one level, and at the same time, the accompanying tube 25 begins to form together with the workpiece on the forming base plate 5. The template assembly gradually transitions from covering the base plate to covering the accompanying tube 25. Since the outer side of the accompanying tube 25 is aligned with the outer side of the forming base plate 5, the template assembly can maintain consistency with the forming base plate 5 and the accompanying tube 25. The sealing ring 33 is provided at the lower end of the template assembly, which seals the template assembly with the forming base plate 5 or the accompanying tube 25 to prevent powder from leaking downward from the gap between the template assembly and the accompanying tube 25 or the forming base plate 5.

[0085] The position-limiting mechanism comprises a telescopic cylinder 34, a telescopic beam 35, a second servo motor, and a second speed reducer. The telescopic beam 35 is movably threaded to the screw 28. The sidewalls of the telescopic beam 35 are mounted on linear guides. The lower end of the telescopic cylinder 34, which is elastically extendable in height, is sealed and fixed to the upper surface of the movable crossbeam 24. The upper end of the telescopic cylinder 34 is sealed and fixed to the lower surface of the telescopic beam 35. The template assembly, the telescopic beam 35, and the inner side of the telescopic cylinder 34 and the surface of the forming base 5 together form a powder-retaining space that is sealed and connected to the forming chamber. The telescopic cylinder 34 is mounted on the movable crossbeam 24, ensuring a powder-tight seal and surrounding the outer contour of the forming base 5. The movable crossbeam 24 controls the vertical inching and rapid resetting of the forming base 5. The top of the telescopic cylinder 34 is connected to the telescopic beam 34, ensuring a precise connection to the powder seal and surrounding the outer contour of the forming base 5. The guide rails ensure the accuracy of the upward and downward displacement.

[0086] The mold assembly includes a main mold plate 31 and a sub-mold plate 32. The frame-shaped main mold plate 31 is fixedly installed on the molding port at the lower end of the laser forming chamber 1, and the sub-mold plate 32 is detachably fixedly installed on the main mold plate 31. The main mold plate 31 and the sub-mold plate 32 are horizontally aligned to form the powder laying base surface of the equipment. The outer circumference of the forming base plate 5 is completely matched with the inner wall of the sub-mold plate 32. The forming base plate 5 or the upper limit piece of the forming base plate 5 can cooperate with the sub-mold plate 32 to form a powder holding space. The main mold plate 31 is a fixed structure that matches the forming port at the lower end of the laser forming chamber 1. The outer wall of the sub-mold plate 32 only needs to match the main mold plate 31, and the inner wall of the sub-mold plate 32 matches the shape of the limiter. When the limiter is the companion cylinder 25, the sub-mold plate 32 matches the shape of the companion cylinder 25 (also square, round and free-shaped), which can minimize the powder holding space. The sub-mold plate 32 can be adjusted according to the size of the workpiece and the size of the limiter that matches the workpiece, realizing free adjustment according to the size of the workpiece and saving powder to the greatest extent. The sub-mold plate 32 can be installed on the main mold plate 31 by screws to realize installation and disassembly. A step surface can be set on the main mold plate 31, and the sub-mold plate 32 is placed on the step surface and then connected by screws. This structure can realize the positioning and installation of the sub-mold plate 32, ensuring that it is horizontally aligned with the main mold plate and the bottom surface of the laser forming chamber 1 after installation.

[0087] A forming table 26 is also provided, which includes a heat insulation plate, a fork plate, a heating plate and a height adjustment plate 36 stacked in sequence from bottom to top. A slot structure is formed on the fork plate for inserting the plug-in plate, and the forming base plate 5 is fixedly installed above the heating plate of the forming table 26. The forming base plate 5 forms a powder holding space with the pattern plate assembly and the stoppers, and also supports the workpiece. The heating plate heats the forming base plate 5 to prevent deformation caused by sudden pre-cooling. After the workpiece is formed, the fork plate and the workpiece above it can be removed using a forklift or other inserting device, facilitating removal. The heat shield prevents heat from the workpiece from transferring to the movable crossbeam 24, ensuring its accuracy. The forming table 26 ideally matches the shape and size of the forming base plate 5, but can also be larger. The forming table 26 replaces the piston, and the forming base plate 5 on top of the forming table 26 replaces the forming plate on top of the piston. The piston height of a conventional SLM machine is similar to that of the forming table 26 in this design. Adding the height of the actuator creates a stroke length S. Due to the characteristics of piston drive, the piston extends a further stroke at the end of its downstroke, resulting in a total length of the piston-actuator-piston rod system approaching 3S (stroke S). This design, however, has a total length of only approximately 2S.

[0088] The frame is also equipped with a forming cover 18 and a forming cylinder 19. The forming cover 18 covers the outside of the laser forming chamber 1 and the laser melting system 17. The forming cover 18 is provided with a forming perspective window 22 for observing the forming process in the laser forming chamber 1 and an upper inspection door 20 for entering the forming cover 18. The upper end of the forming cylinder 19 is connected to the lower end of the forming cover 18. The template assembly, limiter, forming base plate 5 and inching lifting drive device are all covered in the forming cylinder 19. The forming cylinder 19 is provided with a removal door 23 for removing the workpiece and a lower inspection door 21 for entering the forming cylinder 19. The forming cover 18 and the forming cylinder 19 cover the outside of the laser forming chamber, the laser melting system 17, and the peripheral area of ​​the movable crossbeam 24 to provide protection. The perspective window allows observation of the internal processing conditions, and the inspection door allows workers to enter and inspect the equipment.

[0089] The forming base plate 5 is provided with at least one powder leakage hole, and the frame is further provided with a powder leakage channel 38. One end of the powder leakage channel 38 is connected to the powder leakage hole on the forming plate, and the other end of the powder leakage channel 38 can be connected to the exhaust device. The powder leakage channel 38 is provided with a switch. After the part is printed, the switch in the powder leakage channel 38 is opened, and the powder in the powder storage space is directly extracted, reducing direct contact with the powder and facilitating powder cleaning.

[0090] A template method using laser forming technology comprises the following steps:

[0091] Step 1: Install the frame-shaped template assembly and the sealing ring 33 at the molding port at the lower end of the molding chamber, and align the upper end surface of the template assembly with the bottom surface of the molding chamber;

[0092] Step 2: Install the forming base plate 5 on the movable crossbeam 24 or the forming cylinder piston;

[0093] Step 3: The movable crossbeam 24 or the piston of the forming cylinder drives the forming base plate 5 to the initial forming position. At this time, there is a height difference between the forming base plate 5 and the bottom surface of the forming chamber, which is enough for the powder to be spread. A powder storage space is formed between the forming base plate 5 and the template assembly.

[0094] Step 4: The powder scraping device in the molding chamber is started. The powder scraping device scrapes the powder fed into the molding chamber from the powder feeding box into the powder holding space between the molding base plate 5 and the template assembly. The laser melting system 17 laser melts and forms a layer of workpiece cross-section, and simultaneously forms a layer of accompanying tube 25 cross-section on the periphery of the workpiece.

[0095] Step 5: The movable crossbeam 24 or the forming cylinder piston drives the forming bottom plate 5 inches to move downward, and the powder scraping device in the forming chamber scrapes the powder into the powder holding space again. The laser melting system 17 then laser melts and forms a layer of workpiece cross-section on the surface of the workpiece. At the same time, the laser melting system 17 laser melts and forms a layer of accompanying tube 25 cross-section on the surface of the accompanying tube 25. The laser melting process is circulated in this way to finally form a complete workpiece and an accompanying tube 25 that is sleeved around the periphery of the workpiece and has the same height as the workpiece.

[0096] Step 6: The movable crossbeam 24 or the forming cylinder piston descends to separate the workpiece and the accompanying tube 25 from the template assembly, and the accompanying tube 25 and the workpiece are taken out, and then the accompanying tube 25 is removed from the periphery of the workpiece.

[0097] In steps one and two, the main mold plate 31 of the mold plate assembly is obtained by machining, and the main mold plate 31 is fixedly installed on the inner side of the molding port at the lower end of the molding chamber, and a whole plate is fixedly installed on the main mold plate 31, and the whole plate is horizontally aligned with the main mold plate 31 and the bottom surface of the molding chamber. The whole plate completely covers the inner space of the main mold plate 31, and the middle part of the whole plate is fixedly connected to the movable crossbeam 24 or the forming table 26 on the forming cylinder piston. Then, the whole plate is laser cut by the laser melting system 17. After cutting, the part connected to the main mold plate 31 becomes the sub-mold plate 32, and the part fixedly connected to the movable crossbeam 24 or the forming table 26 on the forming cylinder piston becomes the forming bottom plate 5. By using the laser beam of the SLM equipment, the entire sheet is cut according to the inner contour of the template assembly or the outer contour of the forming base plate 5, and the separated parts obtained are the sub-template 32 and the forming base plate 5. This method ensures the perfect matching of the sub-template 32 and the forming base plate 5, avoids the problem of interference between the forming base plate 5 and the sub-template 32 due to processing errors, and realizes the precise positioning of the initial position of the forming base plate 5.

[0098] In steps one and two, the main mold plate 31, the sub-mold plate 32 and the forming base plate 5 of the mold plate assembly are obtained by machining, and the main mold plate 31 is fixedly installed on the inner side of the forming port at the lower end of the molding chamber, the sub-mold plate 32 is fixedly installed on the inner side of the main mold plate 31, and the forming base plate 5 is installed on the forming table 26 of the movable crossbeam 24, wherein the inner contour of the sub-mold plate 32 and the outer contour of the forming base plate 5 are separately processed according to the design, or the outer contour of the forming base plate 5 is processed with the inner contour of the sub-mold plate 32 as a reference, or the inner contour of the sub-mold plate 32 is processed with the outer contour of the forming base plate 5 as a reference.

[0099] The main mold plate 31, the auxiliary mold plate 32 and the forming base plate 5 are machined by milling, wire cutting, etc. The three are respectively manufactured according to the design of the main mold plate 31, the auxiliary mold plate 32 and the forming base plate 5, and can be manufactured in series according to the design requirements; the outer contour of the forming base plate 5 is matched (machined) according to the inner contour of the auxiliary mold plate 32 to obtain the forming base plate 5; or conversely, the inner contour of the main and auxiliary mold plates 32 are matched according to the outer contour of the forming base plate 5 to obtain the inner contour of the mold plate assembly. These two processing methods have higher processing accuracy and greater flexibility.

Claims

1. A template equipment using laser forming technology, comprising a frame, a laser forming chamber, and a laser melting system, wherein the laser forming chamber is fixedly mounted on the frame and the laser melting system is mounted above the laser forming chamber, characterized in that: A template assembly, a limiter, a forming base plate and an inching lifting drive device are also provided. The frame-shaped template assembly can be fixedly installed on the forming port at the lower end of the laser forming chamber. The forming base plate can be lifted and lowered and is located directly below the forming port of the laser forming chamber. The inching lifting drive device drives the forming base plate to move up and down in an inching manner. The upper end of the limiter can be sealed and connected with the inner side of the template assembly, and the lower end of the limiter is sealed and positioned with the forming base plate. A powder holding space is formed between the limiter, the template assembly and the forming base plate. The laser melting system can perform laser melting and forming on the powder in the powder holding space, and the upper surface of the template assembly replaces the scraping base plate. The upper surface of the template assembly is the powder laying base surface, and the "shape" inside the template assembly replaces the forming The "shape" of the inner contour of the cylinder, this structure can change the diameter of the powder holding space by changing the size of the inner diameter of the template assembly and the inner diameter of the limiter, so as to be suitable for the forming of large and small parts. The inch-motion lifting drive device includes an inch-motion control system, a first servo motor, a first reducer, a screw and a movable crossbeam. At least one screw is installed on the frame, and a first drive nut is provided on the movable crossbeam. The first drive nut is movably screwed with each screw. The first servo motor drives each first drive nut to rotate synchronously with the screw through the first reducer. The inch-motion control system controls the start and stop and forward and reverse rotation of the first servo motor. A vertical linear guide is also provided on the frame, and the side wall of the movable crossbeam is installed. On the linear guide rail, the forming base plate is positioned on the movable crossbeam. The limiting component includes a telescopic cylinder, a telescopic beam, a second servo motor and a second reducer. The telescopic beam is provided with a second drive nut, which is movably screwed to the lead screw. The second servo motor drives each second drive nut to rotate synchronously with the lead screw through the second reducer. The side wall of the telescopic beam is installed on the linear guide rail. The lower end of the telescopic cylinder that can elastically expand and contract in the height direction is sealed and fixedly installed on the upper surface of the movable crossbeam. The upper end of the telescopic cylinder is sealed and fixedly installed on the lower surface of the telescopic beam. The template assembly, the telescopic beam, and the inner side of the telescopic cylinder and the surface of the forming base plate can just enclose a powder containing space that is sealed and connected to the forming chamber. Alternatively, the limiter is a companion tube that is synchronously formed with the workpiece on the forming base plate by the laser melting system, the companion tube is sleeved on the outside of the workpiece and is at the same height as the workpiece, the cross-section of the companion tube is square, circular or a conformal shape that matches the shape of the workpiece, the circumferential outer surface of the companion tube is aligned with the outer edge of the forming base plate, and a sealing ring is provided at the lower end of the mold plate assembly for sealing and fixing, the sealing ring is in sealing contact with the circumferential outer surface of at least one of the forming base plate and the companion tube, at least one powder leakage hole is provided on the forming base plate, and a powder leakage channel is also provided on the frame, one end of the powder leakage channel is connected to the powder leakage hole on the forming plate, and the other end of the powder leakage channel can be connected to the exhaust device, and a closing switch is provided on the powder leakage channel.

2. The laser forming technology template equipment according to claim 1, characterized in that: The mold assembly includes a main mold and a sub-mold. The frame-shaped main mold is fixedly installed on the forming port at the lower end of the laser forming chamber, and the sub-mold can be detachably fixed on the main mold. The main mold and the sub-mold are horizontally aligned to form the powder laying base surface of the equipment. The outer circumference of the forming base plate is completely matched with the inner side wall of the sub-mold. The forming base plate or the upper limit piece of the forming base plate can cooperate with the sub-mold to form a powder holding space.

3. The laser forming technology template equipment according to claim 1, characterized in that: A forming table is also provided, which includes a heat insulation plate, a fork plate, a heating plate and a height adjustment plate stacked in sequence from bottom to top. A slot structure is formed on the fork plate for inserting the plug plate, and the forming base plate is fixedly installed above the heating plate of the forming table.

4. The laser forming technology template equipment according to claim 1, characterized in that: The frame is also provided with a forming hood and a forming cylinder. The forming hood is covered on the outside of the laser forming chamber and the laser melting system. The forming hood is provided with a forming perspective window for observing the laser forming chamber and an upper inspection door for entering the forming hood. The upper end of the forming cylinder is connected with the lower end of the forming hood. The template assembly, limit parts, forming base plate and inch-motion lifting drive device are all covered in the forming cylinder. The forming cylinder is provided with a removal door for removing the workpiece and a lower inspection door for entering the forming cylinder.

5. A template forming method using the laser forming technology of the template equipment according to any one of claims 1 to 4, characterized in that: The following steps are involved: Step 1: Obtain the main template of the template assembly by machining, and fix the main template to the inner side of the forming opening at the lower end of the forming chamber, fix a whole plate on the main template, and align the whole plate with the main template and the bottom surface of the forming chamber horizontally, so that the whole plate completely covers the inner space of the main template, and fix the middle part of the whole plate to the movable crossbeam or the forming table on the forming cylinder piston. Then, laser cut the whole plate by the laser melting system. After cutting, the part connected to the main template becomes the sub-template, and the part fixedly connected to the movable crossbeam or the forming table on the forming cylinder piston becomes the forming bottom plate. Install the frame-shaped template assembly and the sealing ring at the forming opening at the lower end of the forming chamber, and align the upper end surface of the template assembly horizontally with the bottom surface of the forming chamber. Step 2: Install the forming base plate on the movable crossbeam or the forming cylinder piston; Step 3: The movable crossbeam or the piston of the forming cylinder drives the forming base plate to the initial forming position. At this time, there is a height difference between the forming base plate and the bottom surface of the forming chamber for the first powder spreading, and a powder holding space is formed between the forming base plate and the template assembly; Step 4: The powder scraping device in the molding chamber is started. The powder scraping device scrapes the powder sent into the molding chamber from the powder feeding box into the powder holding space between the forming base plate and the template assembly. The laser melting system laser melts and forms a layer of workpiece cross-section, and at the same time forms a layer of accompanying tube cross-section on the periphery of the workpiece. Step 5: The movable crossbeam or the forming cylinder piston drives the forming base plate to move downward in an inch motion. The powder scraping device in the forming chamber scrapes the powder into the powder holding space again. The laser melting system then laser melts and forms a layer of workpiece cross-section on the surface of the workpiece. At the same time, it laser melts and forms a layer of accompanying tube cross-section on the surface of the accompanying tube. The laser melting process is circulated in this way to eventually form a complete workpiece and an accompanying tube that is sleeved around the periphery of the workpiece and has the same height as the workpiece. After the part is printed, the switch in the powder leakage channel is turned on and the powder in the powder holding space is directly extracted. Step 6: The movable crossbeam or the forming cylinder piston descends to separate the workpiece and the accompanying tube from the template assembly, remove the accompanying tube and the workpiece, and then remove the accompanying tube from the periphery of the workpiece.

6. The template method of laser forming technology according to claim 5, characterized in that: The main mold plate, auxiliary mold plate and forming base plate of the mold plate assembly are obtained by machining, and the main mold plate is fixedly installed on the inner side of the forming port at the lower end of the molding chamber, the auxiliary mold plate is fixedly installed on the inner side of the main mold plate, and the forming base plate is installed on the forming table of the movable crossbeam or the forming cylinder piston, wherein the inner contour of the auxiliary mold plate and the outer contour of the forming base plate are separately processed according to the design, or the outer contour of the forming base plate is processed with the inner contour of the auxiliary mold plate as the reference, or the inner contour of the auxiliary mold plate is processed with the outer contour of the forming base plate as the reference.

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