3D printing system and powder spreading control method

Abstract

The invention provides a 3D printing system and a powder laying control method. The 3D printing system comprises a forming cavity; a powder feeding mechanism; the first powder laying mechanism is provided with a first scraper, and the first scraper is used for laying the powder provided by the powder feeding mechanism in the forming cavity; the second powder laying mechanism is provided with a second scraper, the second scraper is used for laying the powder provided by the powder feeding mechanism in the forming cavity, and the hardness of a knife edge of the second scraper is larger than that of a knife edge of the first scraper; the control mechanism is connected with the first powder laying mechanism and the second powder laying mechanism and used for controlling the first powder laying mechanism and / or the second powder laying mechanism to execute powder laying operation in the object printing process. By controlling the powder spreading mechanism with the scrapers with different hardness in the 3D printing system, the flexible forming requirement of 3D printed objects can be met.

Description

Technical Field

[0001] The present application relates to the field of 3D printing, and more specifically, to a 3D printing system and a powder spreading control method. Background Art

[0002] 3D printing technology that uses powder as raw material to construct multi-dimensional structural objects has been widely used. During the object printing process, the powdered material needs to be spread into the molding cavity through a scraper, and the powdered material is melted by laser and other means to deposit and mold layer by layer. During the powder spreading process, for the molding of objects with weak structural strength, a soft scraper is usually required to spread the powder to avoid damage to the structure of the printed object. However, in some scenarios, soft scrapers cannot meet the molding requirements of 3D printed objects. For example, when the heat cannot be dissipated in time during the printing of the object, causing bulging or warping, a soft scraper is still used to spread the powder. Because the soft scraper has a high tolerance rate for bulging or warping, it is impossible to eliminate the bulging or warping in time. The continuous accumulation of such bulging or warping may cause the object to fail to print or the overall molding of the object does not meet the corresponding quality standards, and cannot meet the molding requirements of 3D printed objects. Summary of the invention

[0003] The present application provides a 3D printing system and a powder spreading control method to meet the flexible molding requirements of 3D printed objects.

[0004] In a first aspect, a 3D printing system is provided, comprising: a molding chamber; a powder feeding mechanism; a first powder spreading mechanism, the first powder spreading mechanism having a first scraper, the first scraper being used to spread the powder provided by the powder feeding mechanism in the molding chamber; a second powder spreading mechanism, the second powder spreading mechanism having a second scraper, the second scraper being used to spread the powder provided by the powder feeding mechanism in the molding chamber, and the blade hardness of the second scraper being greater than the blade hardness of the first scraper; and a control mechanism, connected to the first powder spreading mechanism and the second powder spreading mechanism, for controlling the first powder spreading mechanism and / or the second powder spreading mechanism to perform a powder spreading operation during printing of an object.

[0005] In a possible implementation, the control mechanism is used to: control the first powder spreading mechanism to perform a powder spreading operation during printing of the support structure of the object; and control the second powder spreading mechanism to perform a powder spreading operation during printing of the main body structure of the object.

[0006] In a possible implementation, the control mechanism is used to: control the first powder spreading mechanism to perform a powder spreading operation; if a protrusion that hinders the movement of the scraper appears on the printed part of the object, control the second powder spreading mechanism to perform a subsequent powder spreading operation.

[0007] In one possible implementation, the control mechanism is used to: if a protrusion that hinders the movement of the scraper appears on the printed part of the object, control the second powder spreading mechanism so that the second scraper moves repeatedly on both sides of the protrusion to lower the height of the protrusion.

[0008] In one possible implementation, the second powder spreading mechanism includes a sensor for measuring the resistance encountered by the second scraper during the powder spreading process, and the control mechanism is used to: when the force sensor measures that the resistance formed by the raised portion on the second scraper reaches a first threshold, control the second powder spreading mechanism so that the second scraper repeatedly moves on both sides of the raised portion to lower the height of the raised portion.

[0009] In a second aspect, a powder spreading control method is provided, characterized in that the method is applied to a 3D printing system, and the 3D printing system includes: a molding chamber; a powder feeding mechanism; a first powder spreading mechanism, the first powder spreading mechanism has a first scraper, and the first scraper is used to spread the powder provided by the powder feeding mechanism in the molding chamber; a second powder spreading mechanism, the second powder spreading mechanism has a second scraper, and the second scraper is used to spread the powder provided by the powder feeding mechanism in the molding chamber, and the blade hardness of the second scraper is greater than the blade hardness of the first scraper; the method includes: in the process of printing an object, controlling the first powder spreading mechanism and / or the second powder spreading mechanism to perform a powder spreading operation.

[0010] In one possible implementation, during the process of printing the object, controlling the first powder-spreading mechanism and / or the second powder-spreading mechanism to perform a powder-spreading operation includes: during the process of printing the support structure of the object, controlling the first powder-spreading mechanism to perform a powder-spreading operation; during the process of printing the main body structure of the object, controlling the second powder-spreading mechanism to perform a powder-spreading operation.

[0011] In one possible implementation, during the process of printing an object, the first powder spreading mechanism and / or the second powder spreading mechanism is controlled to perform a powder spreading operation, including: controlling the first powder spreading mechanism to perform a powder spreading operation; if a protrusion that hinders the movement of a scraper appears on the printed portion of the object, controlling the second powder spreading mechanism to perform a subsequent powder spreading operation.

[0012] In one possible implementation, during the process of printing the object, the first powder spreading mechanism and / or the second powder spreading mechanism are controlled to perform a powder spreading operation, including: if a raised portion that hinders the movement of a scraper appears on the printed portion of the object, the second powder spreading mechanism is controlled so that the second scraper moves repeatedly on both sides of the raised portion to lower the height of the raised portion.

[0013] In one possible implementation, the second powder spreading mechanism includes a sensor, which is used to measure the resistance encountered by the second scraper during the powder spreading process. If a protrusion that hinders the movement of the scraper appears on the printed part of the object, the second powder spreading mechanism is controlled to make the second scraper move repeatedly on both sides of the protrusion, including: when the force sensor measures that the resistance formed by the protrusion on the second scraper reaches a first threshold, the second powder spreading mechanism is controlled to make the second scraper move repeatedly on both sides of the protrusion to reduce the height of the protrusion.

[0014] In the embodiment of the present application, by controlling the powder spreading mechanism with scrapers of different hardness in the 3D printing system, the flexible molding requirements of 3D printed objects can be met. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the related technologies, the drawings required for use in the embodiments or the related technical descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0016] Figure 1 and Figure 2 This is a structural example diagram of a control mechanism of a guide rail motor structure provided in an embodiment of the present application.

[0017] Figure 3 and Figure 4 This is a structural example diagram of a control mechanism of a belt motor structure provided in an embodiment of the present application.

[0018] Figure 5 This is a structural example diagram of a control mechanism for controlling a lifting device provided in an embodiment of the present application.

[0019] Figure 6 It is a flow chart of a powder spreading control method provided in an embodiment of the present application.

[0020] Description of reference numerals:

[0021] 1. Molding cavity; 2. First scraper; 3. Second scraper; 4. Guide rail; 5. Discharge port; 6. Waste port; 7. Base; 8. Slider; 9. Belt; 10. Motor; 11. Pulley; 12. Connecting rod. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field based on the embodiments of the present application belong to the scope of protection of this application.

[0023] 3D printing, also known as additive manufacturing technology, is a technology that manufactures physical objects based on three-dimensional CAD data by accumulating materials layer by layer. There are many types of 3D printing materials, such as metal, ceramic, plastic, resin, etc. The physical state of the material can be divided into: liquid material, powder material, sheet material, etc. There are also many types of 3D printing technology, such as: photo-curing 3D printing technology, fused deposition modeling (FDM) technology, selective laser sintering (SLS) technology, SLM technology, etc.

[0024] SLM technology is a widely used technology in the field of 3D printing for printing objects made of powdered materials.

[0025] SLM technology uses metal powder as raw material to build complex multi-dimensional structures. In traditional SLM technology, metal powder is usually laid in the molding cavity using a powder spreading mechanism, and then the area to be molded is melted and solidified by laser, and the desired object is obtained by molding layer by layer.

[0026] The following uses SLM technology as an example to briefly illustrate the 3D printing of objects made of powdered materials.

[0027] In 3D printing based on SLM technology, the process of laying metal powder into the molding cavity is usually completed by a scraper in the powder spreading mechanism. In the actual object forming process, for the forming of objects with weak structural strength, if a hard scraper is used to spread the powder, it may damage the structure of the object. At this time, a soft scraper is needed to spread the powder. However, if the heat cannot be dissipated in time during the printing process of the object, causing bulging or warping, and a soft scraper is still used to spread the powder, the bulging or warping cannot be eliminated in time due to the high tolerance of the soft scraper for bulging or warping. The continuous accumulation of such bulging or warping may cause the object to fail to print or the overall forming of the object does not meet the corresponding quality standards.

[0028] Let's continue with 3D printing based on SLM technology as an example. In the 3D printing process parameter development stage, experiments are needed to determine the best printing parameters. Printing parameters can include laser power, scanning speed, powder thickness, energy distribution, material properties, etc. These printing parameters directly affect the melting and solidification process of the material. If the process parameters are set improperly, thermal stress may be generated in the printed object during the cooling process, which in turn causes deformations such as bulging or warping. In the parameter development stage, the use of a soft scraper can reduce printing failures caused by improper parameters. This is because the soft scraper can better adapt to the surface and continue to spread powder when encountering deformations such as warping or bulging, thereby avoiding damage to the scraper or affecting the continuity of the printing process. Once the process parameters are stable and the printing process becomes predictable, a hard scraper can be used. A hard scraper can provide more uniform powder spreading and reduce the unevenness of the powder layer, thereby improving the surface quality and dimensional accuracy of the printed object. In other words, in the stage of unstable parameters, a soft scraper provides greater fault tolerance. After the parameters are stable, a hard scraper helps to improve the overall quality of the printed object.

[0029] In summary, it can be seen that if the 3D printing system is only equipped with a scraper of one hardness, it is difficult to meet the flexible molding requirements of 3D printed objects. Therefore, how to meet the flexible molding requirements of 3D printed objects is an urgent problem to be solved.

[0030] In view of the above problems, the present application proposes a 3D printing system, which includes a plurality of powder spreading mechanisms with scrapers of different hardness. During the process of printing an object, the control mechanism controls the powder spreading mechanism with scrapers of different hardness to perform powder spreading operations to meet the flexible molding requirements of the 3D printed object.

[0031] The 3D printing system may include a molding chamber 1, a powder feeding mechanism, a first powder spreading mechanism, a second powder spreading mechanism and a control mechanism.

[0032] The powder feeding mechanism is used to transport the powdered material to a specific position. The specific position refers to the position where the scraper can scrape the powdered material when it moves on the surface of the base 7. There are many ways to transport the powdered material. For example, the powdered material can be transported to the specific position in the form of falling material, that is, the discharge position of the powder feeding mechanism is higher than the base 7. Optionally, the powder feeding mechanism can also transport the powdered material to the specific position of the base 7 at a position lower than the base 7, for example, refer to Figure 1 The powder feeding mechanism can convey the powder material to a position at a certain height above the discharge port 5. The material types of the powder material can be various, such as metal powder, plastic powder, ceramic powder, etc., and the present application does not limit the material type of the powder material.

[0033] The powder feeding mechanism may have various structures, for example, it may be a pneumatic powder feeding mechanism, a piston powder feeding mechanism or a screw powder feeding mechanism. The present application does not limit the specific structure of the powder feeding mechanism.

[0034] The powder spreading mechanism may include a scraper, a base 7 located below the scraper for supporting the powder spreading process of the scraper, etc. The scraper of the powder spreading mechanism is used to spread the powder provided by the powder feeding mechanism on the molding cavity 1. The powder spreading mechanism may have multiple scrapers with different blade hardness. For the sake of ease of description, the scraper with a smaller blade hardness is referred to as the first scraper 2, and the powder spreading mechanism with the first scraper 2 is referred to as the first powder spreading mechanism; the scraper with a blade hardness greater than the blade hardness of the first scraper 2 is referred to as the second scraper 3, and the powder spreading mechanism with the second scraper 3 is referred to as the second powder spreading mechanism.

[0035] The molding cavity 1 is used to provide an environment for molding powdered materials. The molding cavity 1 has a side wall. The shape of the molding cavity 1 surrounded by the side wall can be, for example, rectangular, circular, etc. The shape of the molding cavity 1 can be changed according to demand, and the present application does not specifically limit the shape of the molding cavity 1 surrounded by the side wall.

[0036] There may be a molding platform in the molding cavity 1. The molding platform may be connected to a lifting device. The molding platform may move in the vertical direction with the lifting device. As an example, the molding platform may move to a position a certain layer thickness downward from the cavity opening of the molding cavity 1. The thickness of the powder may be determined according to the specific requirements of the printed object. After the powder spreading mechanism completes one powder spreading, the molding platform is lowered so that the molding platform and the cavity opening of the molding cavity 1 are at a height of a powder layer thickness, and then the powder spreading mechanism performs the next powder spreading.

[0037] The control mechanism is connected to the first powder spreading mechanism and the second powder spreading mechanism, and is used to control the powder spreading mechanism to perform the powder spreading operation during the process of printing the object. The control mechanism can select a suitable scraper to perform the powder spreading operation according to the demand, or the control mechanism can flexibly switch scrapers of different hardness according to the demand. When a scraper with lower hardness is required, the control mechanism can control the first scraper 2 of the first powder spreading mechanism to spread the powder provided by the powder feeding mechanism in the molding cavity 1 by moving in the horizontal direction. When a scraper with higher hardness is required, the control mechanism can control the second scraper 3 of the second powder spreading mechanism to spread the powder provided by the powder feeding mechanism in the molding cavity 1 by moving in the horizontal direction.

[0038] There are many structures of the control mechanism for controlling the powder spreading mechanism to spread the powder. As an example, Figure 1 and Figure 2 As shown, the structure in which the control mechanism controls the powder spreading mechanism to spread powder may be a guide rail 4 motor 10 structure. Figure 1 A front exemplary view showing the control mechanism of the guide rail motor structure, Figure 2The control mechanism of the guide rail motor structure is shown in an exemplary back view. The control mechanism may include a guide rail 4, a slider 8 and a motor 10 ( Figure 1 and Figure 2 The first powder spreading mechanism and the second powder spreading mechanism can be connected to one guide rail 4 through a slider 8, or they can be connected to different guide rails 4 parallel to each other. The first powder spreading mechanism and the second powder spreading mechanism can be controlled by one motor 10, or they can be controlled by different motors 10. The motor 10 controls the slider 8 to make the powder spreading mechanism move back and forth along the direction fixed by the guide rail 4, so that the powder material transported by the powder feeding mechanism can be spread in the molding cavity 1.

[0039] Optionally, in some embodiments, when the control mechanism controls a powder spreading mechanism to perform a powder spreading operation, it can simultaneously control the powder spreading mechanism that is not performing the powder spreading operation to move to a standby position to avoid affecting the normal powder spreading operation of the powder spreading mechanism. Figure 1 and Figure 2 For example, when the first powder spreading mechanism is performing a powder spreading operation, the second powder spreading mechanism can move to the right side without affecting the first powder spreading mechanism's execution of the powder spreading operation, that is, move outside the range of movement of the first powder spreading mechanism when performing a powder spreading operation in the horizontal direction. For example, the second powder spreading mechanism can move to the right side of the waste port 6.

[0040] As another example, Figure 3 and Figure 4 As shown, the structure of the control mechanism for controlling the powder spreading mechanism to spread the powder can be a motor 10 belt 9 structure. The control mechanism may include a motor 10, a belt 9 and a pulley 11 (or a gear). The motor 10 is connected to the belt 9 via the pulley 11 or the gear. When the motor 10 rotates, it can drive the pulley 11 or the gear connected thereto to rotate. When the pulley 11 or the gear rotates, it drives the belt 9 to move. The scraper in the powder spreading mechanism is fixed on the belt 9. When the belt 9 moves, it can drive the scraper fixed thereon to move back and forth along the horizontal axis, so as to achieve the spreading of the powder provided by the powder feeding mechanism in the molding cavity 1.

[0041] In order to facilitate the control of scrapers of different hardness, scrapers of different hardness can be fixed on different belts 9. For example, the first scraper 2 and the second scraper 3 can be respectively connected to two sets of belts 9 parallel to each other in the vertical direction. Different belts 9 can be controlled by one motor 10, or they can be controlled by different motors 10. For the structure in which different belts 9 are controlled by different motors 10, scrapers of different hardness can be independently controlled by different motor 10 belt 9 structures, so that the normal operation of other scrapers can be avoided to be affected by the failure of one set of motor 10 belt 9 structure.

[0042] As another example, Figure 5As shown, the structure of the control mechanism for controlling the powder spreading mechanism to spread powder can also be a structure controlled by a lifting device. The control mechanism may include a lifting device. The lifting device includes a connecting rod 12. There may be multiple connecting rods 12, and the number of connecting rods may be the same as the number of scrapers. Multiple connecting rods 12 are independently connected to multiple scrapers in the powder spreading mechanism. The lifting device can determine the scraper to be spread by adjusting the height of the connecting rod 12. In other words, when a scraper is needed to spread powder, the lifting device in the control mechanism lowers the scraper to a position where the powder provided by the powder feeding mechanism can be spread in the molding cavity 1 by controlling the back and forth movement of the scraper in the horizontal direction, or in other words, when a scraper is needed to spread powder, the lifting device in the control mechanism raises the remaining scrapers that are not working temporarily to a position where the powder provided by the powder feeding mechanism cannot be spread in the molding cavity 1. The height difference between the scraper that performs the powder spreading work and the scraper that does not perform the powder spreading work is greater than or equal to the height of a powder spreading layer thickness. By adjusting the height of the scraper by the control mechanism so that the scraper that does not perform the powder spreading work runs to the standby position, the normal operation of the scraper that performs the powder spreading operation can be avoided. The structure of the lifting device may be, for example, a pneumatic lifting device, a hydraulic lifting device, or an electric lifting device. The present application does not limit the structure of the lifting device.

[0043] During the printing process of the object, the control mechanism can select only one of the multiple hardness scrapers to perform the powder spreading operation according to the demand, or can control multiple hardness scrapers to perform the powder spreading operation according to the demand. An example of controlling multiple hardness scrapers to perform the powder spreading operation according to the demand during the printing process is given below.

[0044] When printing objects with complex structures, for example, when printing objects with suspended or bridging structures, if there is no support structure, the object will be deformed or even collapsed during the printing process. Therefore, in order to improve the success rate of 3D printing, the support structure of the object is usually printed first.

[0045] The support structure is responsible for supporting the object during the printing process, and is peeled off from the main structure of the object after the object is printed. In order to facilitate peeling off from the main structure of the object, the support structure usually adopts printing parameters different from those of the main structure of the object, making the support structure relatively brittle and soft relative to the main structure of the object. At this time, if the powder spreading mechanism uses a scraper with too high hardness, it may damage the support structure and make the support structure unable to form. The inability to form the support structure will further affect the printing of the object. Therefore, in the process of printing the support structure of the object, the control mechanism can control the first powder spreading mechanism to perform the powder spreading operation. Since the blade hardness of the scraper of the first powder spreading mechanism is relatively small, it has a small contact force and a high tolerance to deformation such as protrusions caused by heat accumulation, it is very beneficial to the printing and forming of the support structure.

[0046] After the support structure of the object is printed, the main structure of the object needs to be printed. A large amount of heat will be released during the 3D printing process. The complex structure of the object will easily cause the heat to accumulate in certain areas of the main structure of the object during the molding process, which is difficult to dissipate in time. Uneven heat distribution can easily cause bulges or warping in some areas of the object. If the powder spreading mechanism continues to use the first powder spreading mechanism to spread powder during the printing of the main structure of the object, the first scraper 2 of the first powder spreading mechanism has a small hardness, a small contact force, and a high tolerance for convex deformation. Therefore, it is difficult to eliminate the bulge. If these bulges cannot be eliminated in time during the printing process, they will accumulate as the thickness of the printed layer increases. After accumulating to a certain extent, it will be impossible to repair, so that the printing of the main structure of the object fails and cannot be formed. Therefore, during the printing of the main structure, the control mechanism can control the second powder spreading mechanism to perform the powder spreading operation. The blade hardness of the scraper of the second powder spreading mechanism is relatively large. In the event of a slight bulge, the second scraper 3 of the second powder spreading mechanism will promptly flatten the bulge during the powder spreading movement, thereby reducing the accumulation of warping when the next layer is printed. In some more specific cases, when printing a thin-walled honeycomb heat dissipation component, after being formed to a certain extent, top warping may occur due to heat dissipation and other reasons. If this warping is not handled in time, it will accumulate and cause the print to be scrapped. Through the 3D printing system of the present application, when a slight warping occurs, the second scraper 3 of the second powder spreading mechanism can be controlled to reciprocate, so that the raised part is continuously flattened under the action of the scraper. After the flattening operation is completed, the soft scraper can be switched to continue printing, and finally the printing of the part is completed.

[0047] During the process of printing the support structure and the main body structure, the control mechanism controls the powder spreading mechanism with scrapers of different hardness to perform the powder spreading operation, which can flexibly meet the needs of flexible molding of the object and increase the probability of successful printing of the object.

[0048] The examples given above are for objects that need to print support structures to illustrate that the 3D printing system proposed in this application can meet the needs of flexible molding of objects. For objects that do not need to print support structures but may have protrusions during the printing process, the 3D printing system proposed in this application is also applicable. For example, the control mechanism can be used to control the first powder spreading mechanism to perform the powder spreading operation. However, if it is found that the printed part of the object has a protrusion that hinders the movement of the scraper, the second powder spreading mechanism can be controlled to perform subsequent powder spreading operations. Since the scraper hardness of the second powder spreading mechanism is greater than the scraper hardness of the first powder spreading mechanism, when the Nth layer of the printed object has protrusions such as bulging or warping, when the next layer is printed, the first powder spreading mechanism is controlled to switch to the second powder spreading mechanism to perform the powder spreading operation. At this time, since there is no accumulation in the protruding area, its strength is not high. The scraper of the second powder spreading mechanism can flatten the protruding area during the powder spreading movement, so that such protrusions will not continue to accumulate, which is conducive to the overall molding of the 3D printed object.

[0049] The above-mentioned direct execution of subsequent powder spreading operations by the second powder spreading mechanism is a situation where the obstruction formed by the raised portion does not affect the normal powder spreading of the second powder spreading mechanism. If the obstruction formed by the raised portion affects the normal powder spreading of the second powder spreading mechanism, it may usually cause the printing to be terminated. After the printing is terminated, it is necessary to continue to optimize the process and then reprint. This will cause a waste of time and cost. The 3D printing system proposed in the present application can control the powder spreading mechanism so that the second scraper 3 of the second powder spreading mechanism repeatedly moves on both sides of the raised portion to lower the height of the raised portion until it no longer affects the normal powder spreading operation of the second powder spreading mechanism. At this time, the second powder spreading mechanism can play a role in grinding the raised portion. In this process, the 3D printing system does not need to terminate the printing work, so it can save time and cost under the premise of satisfying the object molding.

[0050] Whether the obstruction formed by the protrusion affects the normal powder spreading of the second powder spreading mechanism can be solved by installing a sensor on the second powder spreading mechanism. The sensor can be used to measure the resistance encountered by the second scraper 3 during the powder spreading process. When the sensor measures that the resistance formed by the protrusion on the second scraper 3 does not reach the first threshold, the control mechanism controls the second powder spreading mechanism to perform normal powder spreading operations. When the sensor measures that the resistance formed by the protrusion on the second scraper 3 reaches the first threshold, the control mechanism controls the second powder spreading mechanism to make the second scraper 3 move repeatedly on both sides of the protrusion to lower the height of the protrusion until the protrusion no longer affects the second powder spreading mechanism to perform subsequent normal powder spreading operations. The first threshold may be related to the strength of the scraper material or the hardness of the printing material. The first threshold may be a value set based on experiments or experience. This application does not limit the specific setting of the first threshold.

[0051] Combination of the above Figures 1 to 3, describes the device embodiment of the present application in detail, and the method embodiment of the present application is described in detail below. It should be understood that the method can be executed by the 3D printing system mentioned above, so the parts not described in detail can refer to the above device embodiment.

[0052] The embodiment of the present application also provides a powder spreading control method. The powder spreading control method is applied to a 3D printing system. Specifically, the 3D printing system includes: a molding chamber; a powder feeding mechanism; a first powder spreading mechanism, the first powder spreading mechanism having a first scraper, the first scraper is used to spread the powder provided by the powder feeding mechanism in the molding chamber; a second powder spreading mechanism, the second powder spreading mechanism having a second scraper, the second scraper is used to spread the powder provided by the powder feeding mechanism in the molding chamber, and the blade hardness of the second scraper is greater than the blade hardness of the first scraper.

[0053] Reference Figure 4 The powder spreading control method 40 may include step S10, that is, in the process of printing an object, controlling the first powder spreading mechanism and / or the second powder spreading mechanism to perform a powder spreading operation.

[0054] Optionally, in some embodiments, method 40 may include: in the process of printing the support structure of the object, controlling the first powder spreading mechanism to perform the powder spreading operation; in the process of printing the main body structure of the object, controlling the second powder spreading mechanism to perform the powder spreading operation.

[0055] Optionally, in some embodiments, method 40 may include: controlling a first powder spreading mechanism to perform a powder spreading operation; and if a protrusion that hinders the movement of a scraper appears on a printed portion of the object, controlling a second powder spreading mechanism to perform a subsequent powder spreading operation.

[0056] Optionally, in some embodiments, method 40 may include: if a protrusion that hinders the movement of the scraper appears on the printed portion of the object, controlling the second powder spreading mechanism so that the second scraper moves repeatedly on both sides of the protrusion to reduce the height of the protrusion.

[0057] Optionally, in some embodiments, the second powder spreading mechanism includes a sensor for measuring the resistance encountered by the second scraper during the powder spreading process. If a raised portion that hinders the movement of the scraper appears on the printed portion of the object, the second powder spreading mechanism is controlled so that the second scraper moves repeatedly on both sides of the raised portion, including: when the force sensor measures that the resistance formed by the raised portion on the second scraper reaches a first threshold, the second powder spreading mechanism is controlled so that the second scraper moves repeatedly on both sides of the raised portion to reduce the height of the raised portion.

[0058] It should be understood that in the embodiment of the present application, determining B based on A does not mean determining B only based on A, but B can also be determined based on A and / or other information.

[0059] It should be understood that in the embodiment of the present application, "B corresponding to A" means that B is associated with A, and B can be determined according to A. However, it should also be understood that determining B according to A does not mean determining B only according to A, and B can also be determined according to A and / or other information.

[0060] It should be understood that the term "and / or" in this article is only a description of the association relationship of the associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0061] It should be understood that in the various embodiments of the present application, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0062] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0063] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0064] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0065] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When loading and executing computer program instructions on a computer, the process or function according to the embodiment of the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions can be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from a website site, a computer, a server or a data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (digital subscriber line, DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) mode to another website site, computer, server or data center. The computer-readable storage medium can be any available medium that a computer can read or a data storage device such as a server, a data center, etc. that contains one or more available media integrated. Available media may be magnetic media (eg, floppy disks, hard disks, magnetic tapes), optical media (eg, digital video discs (DVD)), or semiconductor media (eg, solid state disks (SSD)).

[0066] The above are only specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A 3D printing system, characterized in that: include: Molding cavity; Powder feeding mechanism; a first powder spreading mechanism, the first powder spreading mechanism having a first scraper, the first scraper being used to spread the powder provided by the powder feeding mechanism on the forming cavity; a second powder spreading mechanism, wherein the second powder spreading mechanism has a second scraper, and the second scraper is used to spread the powder provided by the powder feeding mechanism in the molding cavity, and the blade hardness of the second scraper is greater than the blade hardness of the first scraper; The control mechanism is connected to the first powder spreading mechanism and the second powder spreading mechanism, and is used to control the first powder spreading mechanism and / or the second powder spreading mechanism to perform a powder spreading operation during the process of printing an object.

2. The 3D printing system according to claim 1, characterized in that: The control mechanism is used to: During the process of printing the support structure of the object, controlling the first powder spreading mechanism to perform a powder spreading operation; During the process of printing the main structure of the object, the second powder spreading mechanism is controlled to perform a powder spreading operation.

3. The 3D printing system according to claim 1, characterized in that: The control mechanism is used to: Controlling the first powder spreading mechanism to perform a powder spreading operation; If a protrusion that hinders the movement of the scraper appears on the printed part of the object, the second powder spreading mechanism is controlled to perform subsequent powder spreading operations.

4. The 3D printing system according to claim 1, characterized in that: The control mechanism is used to: If a raised portion that hinders the movement of the scraper appears on the printed part of the object, the second powder spreading mechanism is controlled so that the second scraper moves repeatedly on both sides of the raised portion to reduce the height of the raised portion.

5. The 3D printing system according to claim 4, characterized in that: The second powder spreading mechanism includes a sensor, and the sensor is used to measure the resistance encountered by the second scraper during the powder spreading process. The control mechanism is used to: When the force sensor measures that the resistance formed by the protrusion on the second scraper reaches a first threshold, the second powder spreading mechanism is controlled to make the second scraper move repeatedly on both sides of the protrusion to reduce the height of the protrusion.

6. A powder spreading control method, characterized in that: The method is applied to a 3D printing system, and the 3D printing system comprises: Molding cavity; Powder feeding mechanism; a first powder spreading mechanism, the first powder spreading mechanism having a first scraper, the first scraper being used to spread the powder provided by the powder feeding mechanism on the forming cavity; a second powder spreading mechanism, wherein the second powder spreading mechanism has a second scraper, and the second scraper is used to spread the powder provided by the powder feeding mechanism in the molding cavity, and the blade hardness of the second scraper is greater than the blade hardness of the first scraper; The method comprises: During the process of printing an object, the first powder spreading mechanism and / or the second powder spreading mechanism are controlled to perform a powder spreading operation.

7. The method according to claim 6, characterized in that In the process of printing the object, controlling the first powder spreading mechanism and / or the second powder spreading mechanism to perform a powder spreading operation includes: During the process of printing the support structure of the object, controlling the first powder spreading mechanism to perform a powder spreading operation; During the process of printing the main structure of the object, the second powder spreading mechanism is controlled to perform a powder spreading operation.

8. The method according to claim 6, characterized in that In the process of printing the object, controlling the first powder spreading mechanism and / or the second powder spreading mechanism to perform a powder spreading operation includes: Controlling the first powder spreading mechanism to perform a powder spreading operation; If a protrusion that hinders the movement of the scraper appears on the printed part of the object, the second powder spreading mechanism is controlled to perform subsequent powder spreading operations.

9. The method according to claim 6, characterized in that In the process of printing the object, controlling the first powder spreading mechanism and / or the second powder spreading mechanism to perform a powder spreading operation includes: If a raised portion that hinders the movement of the scraper appears on the printed part of the object, the second powder spreading mechanism is controlled so that the second scraper moves repeatedly on both sides of the raised portion to reduce the height of the raised portion.

10. The method according to claim 9, characterized in that The second powder spreading mechanism includes a sensor, and the sensor is used to measure the resistance encountered by the second scraper during the powder spreading process. If a raised portion that hinders the movement of the scraper appears on the printed portion of the object, the second powder spreading mechanism is controlled so that the second scraper moves repeatedly on both sides of the raised portion, including: When the force sensor measures that the resistance formed by the protrusion on the second scraper reaches a first threshold, the second powder spreading mechanism is controlled to make the second scraper move repeatedly on both sides of the protrusion to reduce the height of the protrusion.

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