Additive manufacturing apparatus

Abstract

The present disclosure provides an additive manufacturing apparatus. The additive manufacturing equipment comprises a volume-variable forming bin. The powder laying device is used for laying powder to be formed in the forming bin in the additive manufacturing stage; the high-energy beam generating device is used for generating a high-energy beam in an additive manufacturing stage so as to process powder to be formed; the gas washing device is used for carrying out gas washing operation on the forming bin in the gas washing stage; wherein the forming bin has a first volume corresponding to the additive manufacturing stage and a second volume corresponding to the gas washing stage, and the first volume is larger than the second volume. The additive manufacturing equipment can shorten the gas washing time and improve the equipment utilization rate.

Description

Technical Field

[0001] The present disclosure relates to the technical field of additive manufacturing, and in particular to an additive manufacturing device. Background Art

[0002] Additive manufacturing technology (or 3D printing technology) can use high-energy beams to process powder materials to print out three-dimensional components of specified shapes. After printing a component and before printing the next component, it is usually necessary to take the component out of the molding chamber and use a gas washing device to wash the molding chamber. The relevant technology takes a long time in the gas washing stage, resulting in low equipment utilization. Utility Model Content

[0003] The embodiment of the present application provides an additive manufacturing device to reduce the gas washing time and improve the utilization rate of the equipment.

[0004] The additive manufacturing equipment provided in the embodiment of the present application includes: a molding chamber with variable volume; a powder spreading device, used to spread the powder to be formed in the molding chamber during the additive manufacturing stage; a high-energy beam generating device, used to generate a high-energy beam during the additive manufacturing stage to process the powder to be formed; a scrubbing device, used to perform scrubbing operations on the molding chamber during the scrubbing stage; wherein the molding chamber has a first volume corresponding to the additive manufacturing stage and a second volume corresponding to the scrubbing stage, and the first volume is larger than the second volume.

[0005] As a possible implementation manner, the molding bin includes a first wall portion and a second wall portion that are arranged opposite to each other, and the first wall portion and the second wall portion can move relatively to change the volume of the molding bin.

[0006] As a possible implementation, the molding bin includes: a top wall; and a bottom plate, which is arranged opposite to the top wall; wherein the first wall portion and the second wall portion are side walls arranged between the top wall and the bottom plate.

[0007] As a possible implementation method, the additive manufacturing equipment also includes: a retractable device, which is arranged inside the molding chamber, and the volume of the retractable device has a contracted state and an enlarged state. In the additive manufacturing stage, the volume of the retractable device is in a contracted state, and in the air washing stage, the volume of the retractable device is in an enlarged state.

[0008] As a possible implementation, the retractable device is a flexible inflatable device.

[0009] As a possible implementation, the wall of the molding chamber is provided with an air flow channel which is in fluid communication with the expandable device.

[0010] As a possible implementation, the retractable device is a retractable accordion folding component.

[0011] As a possible implementation manner, the outer wall of the retractable device is made of airtight material.

[0012] In the present application, compared with the additive manufacturing stage, the molding chamber has a smaller volume in the gas washing stage, thereby shortening the gas washing time and improving the utilization rate of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 A schematic diagram of the structure of the additive manufacturing equipment provided in an embodiment of the present application.

[0014] Figure 2 A structural example diagram of a possible implementation of a variable volume molding chamber.

[0015] Figure 3 A structural example diagram of another possible implementation of a variable-volume molding chamber.

[0016] Figure 4 This is a structural example diagram of another possible implementation of a variable-volume molding bin.

[0017] Figure 5a-5c for Figure 1 Schematic diagram of a model of a possible implementation of an additive manufacturing device.

[0018] Figure 6a-6c for Figure 1 Schematic diagram of a model of another possible implementation of an additive manufacturing device.

[0019] Figure 7a-Figure 7b for Figure 1 Schematic diagram of a possible model of a gas scrubber for an additive manufacturing device. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only part of the embodiments of the present disclosure, rather than all of the embodiments.

[0021] Additive manufacturing technology can also be called 3D printing technology. Compared with traditional manufacturing technology, additive manufacturing technology can produce multi-dimensional structures with complex shapes, so it is being widely studied and promoted.

[0022] There are many types of additive manufacturing technologies, such as additive manufacturing technologies based on material extrusion and additive manufacturing technologies based on powders (such as metal powders) and high-energy beams. Metal selective laser melting technology is a typical additive manufacturing technology based on powders and high-energy beams. The following takes metal selective laser melting technology as an example to briefly introduce the additive manufacturing process.

[0023] Metal selective laser melting technology uses metal powder as raw material to construct complex multi-dimensional structures. The powder material is melted by focusing a high-energy light beam and solidified again to obtain the specified spatial component. The additive manufacturing process is usually carried out in a closed molding chamber. After the component is printed and molded once, it is necessary to take out the component, reload the metal powder, close the chamber door, and keep the molding chamber closed again. Before the next printing begins, it is often necessary to remove the air in the molding chamber to ensure that the elements that need to be controlled, such as oxygen in the molding chamber, are within a controllable range. This air removal process is also called purge. For example, inert gas can be filled into the molding chamber to place the molding chamber in an inert gas atmosphere. After the purge is completed, the additive manufacturing stage can be entered to further carry out processing processes such as powder laying and laser scanning.

[0024] In order to ensure that the gas composition in the molding chamber meets the specified requirements, the purge process often needs to be repeated many times. During the purge stage, the entire equipment is in a waiting state of stopping work (stopping 3D printing or additive manufacturing) until the impurity elements that need to be controlled are in the required state, and then the equipment can be started for printing, which leads to low equipment utilization.

[0025] Whether the content of gas components meets the standard will directly affect the quality of the printed components. If the quality of the components does not meet the standard due to shortening the purge time, it will not be worth the loss. Therefore, the relevant technology generally believes that the high time consumption of the purge stage is necessary.

[0026] It is true that the quality of air washing should not be reduced in order to improve equipment utilization. However, it is possible to shorten the duration of the air washing stage while ensuring the quality of air washing. The inventors have found that the duration of the air washing stage is closely related to the volume of the molding bin. In other words, if the volume of the molding bin is small, the duration of the air washing stage is relatively short; if the volume of the molding bin is large, the duration of the air washing stage will be relatively long. The internal volume of the molding bin used in related technologies is often fixed, which is not conducive to reducing the time of the air washing stage.

[0027] In view of the above problems, the embodiment of the present application proposes a molding bin with variable volume. The embodiment of the present application is described in detail below.

[0028] Figure 1 Schematic diagram of the structure of the additive manufacturing equipment provided in the embodiment of the present application. Figure 1As shown, the additive manufacturing device 1 includes a molding bin 10, a powder spreading device 20, a high energy beam generating device 30, and an air washing device 40. In addition to the above devices, the additive manufacturing device 1 may also include other devices, such as a first powder bin 71 and a second powder bin 72, and a molding platform 80.

[0029] The molding bin 10 or molding cabin, in some implementations, can be made of high-strength and high-temperature resistant materials, and at least include a top wall, a bottom wall, and surrounding side walls. The top opening of the molding bin 10 does not exceed the horizontal reference plane of the bottom wall, and the surrounding side walls extend downward in the vertical direction. In some embodiments, the sealed molding bin 10 can include a surrounding sheet metal structure, which is sealed and covered with transparent glass on top.

[0030] It is understood that the molding chamber 10 refers to a closed space in the additive manufacturing device 1, and may also include an optical path system. The main function of the molding chamber 10 is to provide a controlled environment during the additive manufacturing process to ensure the successful construction of the component. The closed nature of the molding chamber helps prevent the entry of external impurities, and also helps to maintain the atmosphere and temperature conditions required for molding the component.

[0031] The molding platform 80 is located at the bottom of the molding chamber 10. The bottom of the molding platform 80 is usually connected to a molding cylinder or a height adjustment device to adjust the height of the molding platform 80. The molding platform 80 is used to carry powder materials to form a powder bed, and is built layer by layer by a high-energy beam from above. The types of powder materials include but are not limited to metal powder, nylon powder, polymer powder, biomaterial powder, ceramic powder, and mixed powder.

[0032] The powder spreading device 20 is located inside the molding bin 10 and on the upper part of the molding platform 80. The powder spreading device 20 can be used to spread the powder to be formed in the molding bin 10 during the additive manufacturing stage. The powder spreading device 20 can transport the powder material overflowing from the first powder bin 71 and spread it evenly on the molding platform 80. The powder spreading device 20 can be in the form of a rolling structure, that is, a rolling component, such as a roller or a drum. The powder spreading device 20 can also be in the form of a planar movement, such as a scraper. Among them, the powder spreading device 20 in the form of a rolling structure has a better powder spreading effect for laying ultrafine metal powder. For example, the powder spreading device 20 can use rollers and other mechanisms to spread the powder to be formed in the first powder bin 71 layer by layer on the molding platform 80.

[0033] In some implementations, the powder spreading device 20 can be a scraper type. The powder spreading device 20 can include at least a slide rail beam and a slider scraper. Among them, the slide rail beam is arranged on the bottom wall of the molding bin 10 and extends along the first horizontal direction. The slider scraper can include a slider base and a scraper component fixedly arranged on the slider base, the slider scraper is slidably arranged on the slide rail beam through the slider base, and the slider base is connected to the driving element, and the slider scraper can reciprocate horizontally driven by its slider base. In other words, the slider base is connected to the driving element in a transmission manner to move left and right in a controlled manner in the first horizontal direction, and the scraper component is extended along the second horizontal direction. Usually the second horizontal direction can be perpendicular to the first horizontal direction. For example, the first horizontal direction can be the length direction of the molding bin 10, and the second horizontal direction can be the width direction of the molding bin 10.

[0034] The high-energy beam generating device 30 is usually located on the top wall of the molding bin 10, and the high-energy beam generating device 30 can be used to generate a high-energy beam. The high-energy beam generating device 30 is used to selectively generate a high-energy beam (such as a laser beam) to act on the surface of the powder on the molding platform 80, sintering / melting it to build a component layer by layer. The high-energy beam mentioned here can be a laser or other types of ion beams. In some embodiments, the high-energy beam generating device 30 can be driven by a certain motion mechanism to aim the high-energy beam at the powder to be molded on the molding platform 80, so that the powder to be molded is focused, melted, and then solidified to form.

[0035] In some implementations, the high-energy beam generating device 30 may include a laser, an optical fiber, an optical fiber coupler, an optical fiber splitter, an optical fiber receiver, a scanning lens, and a focusing lens. Among them, the laser is used to generate a laser beam, the optical fiber is used to transmit the laser beam, the optical fiber coupler is used to couple the laser beam into the optical fiber, the optical fiber splitter is used to divide the laser beam into multiple paths, the optical fiber receiver is used to converge the split laser beams, the scanning lens (also called a scanning galvanometer) is used to control the scanning path of the laser beam, and the focusing lens (also called a field lens) is used to focus the laser beam onto the powder layer on the molding platform 80.

[0036] For example, in the additive manufacturing process, after the powder laying device 20 completes the construction of each layer of powder material, the laser scanning of the high-energy beam generating device 30 sintered / melted the powder layer to form it, and then the forming platform 80 was lowered to a predetermined height. The predetermined height corresponds to the thickness of the powder layer, so that the next layer of powder can be laid and formed, and then the desired object is gradually constructed. Preferably, the predetermined height to which the forming platform 80 is lowered can be set to 40μm.

[0037] The scrubber 40 can be connected to the top wall or side wall of the molding chamber 10 through a pipeline interface. The scrubber 40 can fill the molding chamber 10 with gas such as helium or argon, thereby exhausting the air in the molding chamber 10, so that the interior of the molding chamber 10 is in an inert gas atmosphere.

[0038] In some implementations, the scrubbing device 40 may include a vacuuming device for evacuating the molding bin 10 during the scrubbing stage, and an inert gas filling device for filling the molding bin 10 with an inert gas during the scrubbing stage. The vacuum exhaust device may be connected to the internal space of the molding bin 10 through a pipeline component, and is used to extract the air in the molding bin 10, reduce the oxygen content in the molding chamber, and prevent oxidation of the metal material. The inert gas filling device may include an inert protective gas source disposed outside the molding bin 10, and the inert protective gas source is connected to the internal space of the molding bin 10 through a pipeline component, and is used to fill the molding bin 10 with an inert protective gas. In some embodiments, the oxygen content in the molding bin 10 after scrubbing may be lower than 100 ppm.

[0039] It should be understood that in actual operation, the operation logic of the gas washing device 40 can be set according to actual conditions. For example, in some operational practices, the gas washing action is to continuously pump inert gas into the molding chamber through the gas source, and at the same time open the gas outlet of the molding chamber, so that the inert gas continuously occupies the molding chamber space and the air is continuously discharged to the outside of the molding chamber. Of course, from the actual operation effect, this method has a poor gas washing effect. If the gas washing operation can be carried out simultaneously with the vacuum device, the gas washing time can be further saved.

[0040] The molding chamber 10 is a molding chamber with a variable volume. The molding chamber 10 has a first volume corresponding to the additive manufacturing stage and a second volume corresponding to the gas washing stage, and the first volume is greater than the second volume. The so-called first volume corresponding to the additive manufacturing stage refers to the first volume of the molding chamber 10 in the additive manufacturing stage (or 3D printing stage). The so-called second volume corresponding to the gas washing stage refers to the second volume of the molding chamber 10 in the gas washing stage (i.e. before 3D printing, or between two 3D printings). Since the second volume is smaller than the first volume, it is equivalent to using a small-volume molding chamber 10 for gas washing in the gas washing stage, and restoring the large volume of the molding chamber for additive manufacturing in the additive manufacturing stage, which can shorten the gas washing time and improve equipment utilization.

[0041] There are many ways to achieve variable volume of the molding bin 10, which are described in detail below with reference to some possible embodiments of the present application.

[0042] Embodiment 1

[0043] The molding bin 10 may include a first wall portion 12 and a second wall portion 14 that are disposed opposite to each other. The first wall portion 12 and the second wall portion 14 may move relative to each other to change the volume of the molding bin 10. The first wall portion 12 may be any side wall.

[0044] In some implementations, the first wall portion 12 may be fixedly disposed, and the second wall portion 14 may be movable toward the first wall portion 12 .

[0045] In some implementations, the second wall portion 14 may be fixedly disposed, and the first wall portion 12 may be movable toward the second wall portion 14 .

[0046] In some implementations, both the first wall portion 12 and the second wall portion 14 are movable.

[0047] In some implementations, such as Figure 2 As shown, the molding bin 10 may include a top wall 16 and a bottom plate 18 disposed opposite to each other. The first wall portion 12 and the second wall portion 14 mentioned above are two opposite side walls between the top wall 16 and the bottom plate 18, respectively.

[0048] In some implementations, the first wall portion 12 and the second wall portion 14 may also be a top wall 16 and a bottom plate 18 , respectively.

[0049] Before the gas washing starts, the first wall portion 12 and the second wall portion 14 can move relative to each other to reduce the volume of the molding chamber 10 (ie, the volume of the molding chamber 10 is the second volume mentioned above). Figure 2 As shown, the first wall portion 12 can be moved to the position marked by A; the second wall portion 14 can be moved to the position marked by B. In the scrubbing stage, since the volume of the molding chamber 10 becomes smaller, the scrubbing can be completed quickly. After the scrubbing is completed, the first wall portion 12 and the second wall portion 14 can move relative to each other to restore the volume of the molding chamber 10 (that is, the volume of the molding chamber 10 is the first volume mentioned above).

[0050] The relative movement of the first wall portion 12 and the second wall portion 14 can be performed under the control of a movable device, which can be implemented by a mechanism such as a slide rail, a gear rack, etc.

[0051] Embodiment 2

[0052] The additive manufacturing equipment 1 may further include a retractable device 50. The retractable device 50 may be arranged inside the molding bin 10. The volume of the retractable device 50 has a contracted state and an enlarged state. In the additive manufacturing stage, the volume of the retractable device 50 is in a contracted state, and in the gas washing stage, the volume of the retractable device 50 is in an enlarged state. That is to say, in the gas washing stage, the volume of the retractable device 50 is in an enlarged state, thereby occupying a larger space of the molding bin 10, thereby reducing the space inside the molding bin 10 that needs to be washed. In the additive manufacturing stage, the retractable device 50 returns to the contracted state, so that the molding bin 10 can process components with a larger volume.

[0053] The outer wall of the retractable device 50 is made of airtight material, so as to be isolated from the air in the space of the molding bin 10 .

[0054] There are many ways to implement the retractable device 50. Figure 3 and Figure 4 , giving examples of two possible implementations.

[0055] like Figure 3 As shown, the retractable device 50 can be a flexible expandable device. Further, in some implementations, the wall of the molding chamber 10 is provided with an air channel 60 in fluid communication with the expandable device, so that the flexible expandable device can be inflated and deflated through the air channel 60.

[0056] Exemplarily, the air flow channel 60 can be tightly connected to the side wall of the molding bin 10, and the opening and closing of the air flow channel 60 can be controlled by a valve. The outside of the air flow channel 60 can be connected to a gas charging device (not shown in the figure). The end of the air flow channel 60 located on one side of the molding bin can be connected to the flexible expandable device, and the flexible expandable device can expand when filled with gas (note that the gas in the flexible expandable device is isolated from the space in the molding bin 10). After printing is completed, the flexible expandable device can expand when filled with gas, thereby occupying the physical space in the molding bin 10. The physical space can compress the space of the molding bin 10. At this time, washing can greatly reduce the washing time. After the washing is completed, the valve is opened, and the flexible expandable device shrinks, thereby restoring the actual space of the molding bin 10.

[0057] In some embodiments, the flexible expandable device has a maximum expansion limit. When the gas washing process is a vacuuming process, the maximum expansion limit can ensure that the expandable device does not expand infinitely due to the vacuum degree in the molding chamber, causing pollution or influence on other components in the molding chamber.

[0058] like Figure 4As shown, the retractable device 50 can be a retractable accordion folding assembly (or a flexible folding assembly). The accordion folding assembly can be opened and closed inside the molding chamber 10 under the control of the movable device. The movable device can be implemented by a mechanism such as a slide rail, a gear rack, etc. The movable device can be a synchronous belt, a pulley mechanism, or an electric cylinder mechanism.

[0059] For example, a retractable accordion folding assembly can be provided on one side of the molding chamber 10. The flexible folding assembly can be moved inside the molding chamber under the traction of the movable device. For example, during the additive manufacturing process, the movable device can compress the folding assembly to be close to one side of the molding chamber 10 (such as Figure 4 When the additive manufacturing is completed and the air needs to be washed, the mobile device can pull the folding assembly to occupy most of the space of the entire molding chamber 10 (as shown in the left figure). Figure 4 As shown in the right figure in the figure, the absolute space of the molding chamber 10 is reduced, which greatly saves the washing time. When the washing is completed, the movable device pulls the folding assembly to be compressed onto the side wall of the molding chamber 10. In this example, the folding assembly is made of airtight material, which can isolate the inside and outside of the assembly to make it airtight. At the same time, the side wall of the folding assembly can be installed to connect the inside and outside of the folding assembly through a valve 90, so that the folding assembly can maintain the same internal and external air pressure during the movement and be in an unfolded state.

[0060] In some embodiments, when the gas washing process is a vacuuming process, the accordion folding component has a certain strength, and the material of the folding component will not be damaged or deformed due to the vacuum state in the molding chamber.

[0061] In some embodiments, in order to cope with the change of vacuum degree in the molding chamber during the washing process, a double-layer folding component can be provided. The folding component in the outer layer has a certain strength to ensure that the vacuum degree in the molding chamber does not change and does not deform. The inner layer material of the folding component is an airtight material. The inner layer of the airtight material can have a flexible characteristic. When the folding component is filled with gas connected to the outside world so that the folding component occupies the space in the molding chamber, the inner layer material maintains the designed shape under the action of the outer layer material. It should be understood that in the design of the folding component as a double-layer material, whether the outer layer material of the folding component is airtight becomes an optional condition.

[0062] In some embodiments, in order to maintain the pressure in the molding chamber at a safe threshold, a vacuum pump may be used to remove the air in the molding chamber and an inert gas may be introduced into the molding chamber at the same time during the gas washing process. This method can improve the efficiency of gas washing and ensure that a certain air pressure is maintained in the molding chamber to prevent the molding chamber from being damaged by excessively high or low pressure in the molding chamber. Such damage includes but is not limited to excessively low pressure in the molding chamber and excessive pressure exerted on the molding chamber structure by the external atmospheric pressure, causing deformation of the closed structure of the molding chamber.

[0063] Embodiment 3

[0064] Figure 5a for Figure 1 Schematic diagram of a model of a possible implementation of an additive manufacturing device. Figure 5a This is also a schematic diagram of using a synchronous belt mechanism to achieve the extension and retraction of the retractable device 50. Figure 5a As shown, the additive manufacturing equipment 500 may include a molding bin 10 , a powder spreading device 20 , a high-energy beam generating device 30 , an air washing device 40 , a retractable device 50 , a first powder bin 71 , a second powder bin 72 , and a molding platform 80 .

[0065] The molding bin 10 can be made of high-strength and high-temperature resistant materials, including a top wall, a bottom wall and four side walls, and the four side walls extend downward in a vertical direction. The side walls and top wall of the molding bin 10 can be sealed and covered with wide-band transparent glass.

[0066] The molding platform 80 is located at the bottom of the molding bin 10. The bottom of the molding platform 80 can be connected to a molding cylinder to adjust the height of the molding platform 80. The molding platform 80 is used to carry powder materials to form a powder bed, and is built layer by layer by a high-energy beam from above. The first powder bin 71 and the second powder bin 72 are used to store and provide powder materials.

[0067] The powder spreading device 20 is located inside the molding bin 10 and on the upper part of the molding platform 80. The powder spreading device 20 can be used to spread the powder to be molded in the molding bin during the additive manufacturing stage. The powder spreading device 20 can transport the powder material overflowing from the first powder bin 71 and evenly spread it on the molding platform 80.

[0068] The powder spreading device 20 can be a scraper powder spreading type. The powder spreading device 20 can include at least a slide rail beam and a slider scraper. Among them, the slide rail beam is arranged on the bottom wall of the molding bin 10 and extends along the first horizontal direction. The slider scraper can include a slider base and a scraper component fixedly arranged on the slider base, the slider scraper is slidably arranged on the slide rail beam through the slider base, and the slider base is connected to the driving element, and the slider scraper can reciprocate horizontally driven by its slider base. In other words, the slider base is transmission-connected to the driving element to move left and right in a controlled manner in the first horizontal direction, and the scraper component is extended along the second horizontal direction. Usually the second horizontal direction can be perpendicular to the first horizontal direction. For example, the first horizontal direction can be the length direction of the molding bin 10, and the second horizontal direction can be the width direction of the molding bin 10.

[0069] The high-energy beam generator 30 may be located on the top wall of the molding chamber 10, and is used to generate a high-energy beam. The high-energy beam generator 30 is used to selectively generate a high-energy beam (e.g., a laser beam) to act on the surface of the powder on the molding platform 80, sintering / melting it to build a component layer by layer. The high-energy beam generator 30 may be an infrared laser, which is used to guide the laser path and focus the light spot. The high-energy beam generator 30 may be driven by a certain motion mechanism to aim the high-energy beam at the powder to be molded on the molding platform 80, so that the powder to be molded is focused, melted, and then solidified to form.

[0070] In the additive manufacturing process, after the powder laying device 20 completes the construction of each layer of powder material, the laser scanning of the high-energy beam generator 30 sintered / melted the powder layer to form it, and then the molding platform 80 was lowered to a predetermined height, which corresponds to the thickness of the powder layer, so as to lay and form the next layer of powder, and then gradually build the desired object. Preferably, the predetermined height to which the molding platform 80 is lowered can be set to 40μm.

[0071] The gas scrubber 40 can be connected to the side wall of the molding chamber 10 through a pipeline interface. The gas scrubber 40 can fill the molding chamber 10 with gas such as helium or argon, thereby exhausting the air in the molding chamber 10, so that the interior of the molding chamber 10 is in an inert gas atmosphere.

[0072] The scrubbing device 40 may include a vacuuming device 41 for evacuating the molding bin 10 during the scrubbing stage, and an inert gas filling device 42 for filling the molding bin 10 with an inert gas during the scrubbing stage. Figure 7a for Figure 5a Schematic diagram of a model of a vacuum extraction device in an additive manufacturing device. Figure 7b for Figure 5a A schematic diagram of a model of an inert gas filling device in an additive manufacturing device. Figure 5a , Figure 7a , Figure 7bAs shown, the vacuum device 41 can be connected to the internal space of the molding bin 10 through a pipeline component, and is used to extract the air in the molding bin 10, reduce the oxygen content in the molding chamber, and prevent oxidation of the metal material. The inert gas filling device 42 may include an inert protective gas source arranged outside the molding bin 10, and the inert protective gas source is connected to the internal space of the molding bin 10 through a pipeline component (such as a pressure gauge, a solenoid valve, etc.), and is used to fill the molding bin 10 with inert protective gas. The vacuum device 41 can also include a wind field blowing port 411 and a wind field suction port 412 arranged in the molding bin 10, a dust removal filter unit 413 and a circulating fan 414 arranged outside the molding bin 10, and the wind field blowing port and the wind field suction port are usually arranged on both sides of the molding bin 10 in a relative arrangement. In some embodiments, the oxygen content in the molding bin 10 after air washing can be lower than 100ppm.

[0073] It should be understood that in the above-mentioned embodiment, the vacuum device 41 may include a vacuum pump and a pipeline system. Figure 5a It also serves as the gas circulation system of the additive manufacturing device 500. During the printing process, the inert gas stops being pumped in, and the gas in the closed chamber can be circulated in a closed system through the vacuum system 41. Of course, the above structural design is for the purpose of achieving economy and compactness of the equipment. If it is only considered from a functional point of view, a vacuum system can be designed separately. The system may include a vacuum pump and a pipeline, and the pipeline can be connected to the molding chamber. When it is necessary to quickly discharge the gas inside the molding chamber, the vacuum system can be started to quickly discharge the gas inside the molding chamber.

[0074] The retractable device 50 can be a retractable accordion folding component 53 provided on one side of the molding bin 10. One side of the flexible folding component 53 is fixed to a side wall (such as the left side wall) of the molding bin 10, and the other side is connected to a synchronous belt 52 through a connecting rod 51, and the synchronous belt 52 is driven by a reducer and a pulley. The flexible folding component 53 can move inside the molding bin under the traction of the connecting rod 51 and the movable device (synchronous belt 52), that is, it can be opened and closed inside the molding bin 10. The operation process of the flexible folding component 53 is described below.

[0075] For example, during the additive manufacturing process, the synchronous belt 52 can compress the folding assembly 53 to be close to one side of the molding chamber 10, such as Figure 5a As shown, the volume of the molding chamber 10 at this time is the first volume corresponding to the additive manufacturing stage. When air washing is required after the additive manufacturing is completed, the synchronous belt 52 can pull the folding assembly 53 to move to the other side of the molding chamber 10, such as Figure 5b The synchronous belt 52 can pull the folding assembly 53 to occupy most of the space of the entire molding bin 10, such as Figure 5cAs shown (the scrubbing device is not shown), the volume of the molding chamber 10 at this time is the second volume corresponding to the scrubbing stage. After the scrubbing is completed, the synchronous belt 52 pulls the folding assembly 53 to be compressed onto the left wall of the molding chamber 10. This is equivalent to using a small volume molding chamber 10 for scrubbing in the scrubbing stage, and restoring the large volume of the molding chamber for additive manufacturing in the additive manufacturing stage. Since the second volume is smaller than the first volume, the absolute space of the molding chamber 10 is reduced, which helps to save scrubbing time and improve equipment utilization.

[0076] The folding assembly 53 is made of airtight material, which can isolate the inside and outside of the assembly to make it airtight. At the same time, the side wall of the folding assembly 53 can be connected to the inside and outside of the folding assembly through a valve, so that the folding assembly 53 can be in an unfolded state while maintaining the same air pressure inside and outside during movement.

[0077] Embodiment 4

[0078] Figure 6a for Figure 1 Schematic diagram of a model of another possible implementation of an additive manufacturing device. Figure 6a This is also a schematic diagram of using an electric cylinder mechanism to achieve the extension and retraction of the retractable device 50. Figure 6a As shown, the additive manufacturing equipment 600 may include a molding bin 10 , a powder spreading device 20 , a high-energy beam generating device 30 , an air washing device 40 , a retractable device 50 , a first powder bin 71 , a second powder bin 72 , and a molding platform 80 .

[0079] The molding bin 10 can be made of high-strength and high-temperature resistant materials, including a top wall, a bottom wall and four side walls, and the four side walls extend downward in a vertical direction. The side walls and top wall of the molding bin 10 can be sealed and covered with wide-band transparent glass.

[0080] Among them, the molding platform 80, the powder spreading device 20, the high energy beam generating device 30, the gas washing device 40, the first powder bin 71, and the second powder bin 72 can refer to the above description and will not be repeated here.

[0081] The retractable device 50 may be a retractable accordion folding assembly 53 provided on one side of the molding bin 10. One side of the flexible folding assembly 53 is fixed to a side wall (such as the left side wall) of the molding bin 10, and the other side is connected to an electric cylinder 54. The electric cylinder 54 may be a single-stage cylinder or a multi-stage cylinder, for example, a three-stage cylinder. The flexible folding assembly 53 may be moved inside the molding bin 10 under the traction of the electric cylinder 54, that is, it may be opened and closed inside the molding bin 10. The operation process of the flexible folding assembly 53 is described below.

[0082] During the additive manufacturing process, the electric cylinder 54 is retracted, and the folding assembly 53 can be compressed to be close to one side of the molding chamber 10, such as Figure 6bAs shown (the scrubbing device is not shown), the volume of the molding chamber 10 is the first volume corresponding to the additive manufacturing stage. When the additive manufacturing is completed and scrubbing is required, the electric cylinder 54 gradually extends and can pull the folding assembly 53 to move to the other side of the molding chamber 10, such as Figure 6a The electric cylinder 54 can pull the folding assembly 53 to occupy most of the space of the entire molding bin 10, such as Figure 6c As shown (the scrubbing device is not shown), the volume of the molding chamber 10 at this time is the second volume corresponding to the scrubbing stage. When the scrubbing is completed, the electric cylinder 54 pulls the folding assembly 53 to be compressed onto the left wall of the molding chamber 10. This is equivalent to using a small volume molding chamber 10 for scrubbing in the scrubbing stage, and restoring the large volume of the molding chamber for additive manufacturing in the additive manufacturing stage. Since the second volume is smaller than the first volume, the absolute space of the molding chamber 10 is reduced, which helps to save scrubbing time and improve equipment utilization.

[0083] The above is only a specific embodiment of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any person skilled in the art who is familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present disclosure, which should be included in the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be based on the protection scope of the claims.

Claims

1. An additive manufacturing device, characterized in that: include: A molding chamber with variable volume; A powder spreading device, used for spreading the powder to be formed in the forming bin during the additive manufacturing stage; A high-energy beam generating device, used to generate a high-energy beam in the additive manufacturing stage to process the powder to be formed; A scrubbing device, used for scrubbing the molding bin during the scrubbing stage; The molding chamber has a first volume corresponding to the additive manufacturing stage and a second volume corresponding to the gas washing stage, and the first volume is larger than the second volume.

2. The additive manufacturing device according to claim 1, characterized in that: The molding bin includes a first wall portion and a second wall portion that are arranged opposite to each other. The first wall portion and the second wall portion can move relatively to change the volume of the molding bin.

3. The additive manufacturing device according to claim 2, characterized in that: The molding chamber comprises: top wall; A bottom plate, arranged opposite to the top wall; Wherein, the first wall portion and the second wall portion are side walls arranged between the top wall and the bottom plate.

4. The additive manufacturing device according to claim 1, characterized in that: Also includes: A retractable device is arranged inside the molding bin, and the volume of the retractable device has a contracted state and an enlarged state. In the additive manufacturing stage, the volume of the retractable device is in a contracted state, and in the air washing stage, the volume of the retractable device is in an enlarged state.

5. The additive manufacturing device according to claim 4, characterized in that: The retractable device is a flexible expandable device.

6. The additive manufacturing device according to claim 5, characterized in that: The wall of the molding bin is provided with an air flow channel which is in fluid communication with the expandable device.

7. The additive manufacturing device according to claim 4, characterized in that: The retractable device is a retractable accordion folding component.

8. The additive manufacturing device according to claim 4, characterized in that: The outer wall of the retractable device is made of airtight material.

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