Laser overlap calibration method for additive manufacturing equipment, additive manufacturing equipment and tooling

Abstract

This invention relates to the field of equipment calibration technology, specifically to a laser overlap calibration method, additive manufacturing equipment, and tooling for additive manufacturing equipment. The laser overlap calibration method for additive manufacturing equipment includes: heating the working cavity until the temperature reaches the sintering temperature, stabilizing it for a certain period to allow the thermal deformation of the additive manufacturing equipment to stabilize; placing multiple tooling fixtures in the laser overlap area; equipping the tooling fixtures with data acquisition components; activating the tooling fixtures and cooling the data acquisition components; adjusting the top surface of the data acquisition components to coincide with the actual sintering surface; using laser beam emission to scan and display the calibration overlap pattern; photographing and analyzing the pattern to determine galvanometer control. This application first stabilizes the deformation by simulating a sintering state before collecting overlap calibration data, thus improving the accuracy and efficiency of laser overlap calibration. Furthermore, the tooling suppresses the temperature of the data acquisition components, thereby obtaining accurate data.

Description

Technical Field

[0001] This invention relates to the field of equipment calibration technology, specifically to a laser overlap calibration method for additive manufacturing equipment, additive manufacturing equipment, and tooling. Background Technology

[0002] For selective laser sintering (SLS) equipment, most systems suffer from laser overlap issues, necessitating laser overlap calibration. In practice, as the working cavity temperature of additive manufacturing equipment rises, it causes deformation of the mechanical structure. This deformation is difficult to compensate for using finite element analysis, making it challenging to achieve ideal laser overlap calibration results in multiple sintering and adjustments. Therefore, laser overlap calibration is initially performed at room temperature, followed by compensation based on the state of the sintered workpiece. The actual sintering temperature ranges from 80 to 150 degrees Celsius, varying depending on the material. Most of the compensation is due to deformation of mechanical components such as the galvanometer mounting plate and side plates caused by changes in the working cavity temperature field, making deformation simulation and compensation quite complex. Furthermore, the top and side plates are mounted with screws, and their deformation becomes unpredictable with rising temperatures, resulting in a large computational burden for compensation. Additionally, differences in equipment, installation errors, and other factors can lead to variations in compensation. Even though water cooling of the galvanometer mounting plate can reduce the aforementioned deformation, other structural components such as side plates still exhibit deformation. The deformation caused by the temperature increase has a significant impact on laser overlap calibration. Summary of the Invention

[0003] Therefore, the technical problem to be solved by the present invention is to overcome the defect that the laser overlap calibration is seriously affected by the increase in working cavity temperature.

[0004] To address the above problems, this invention provides a laser overlap calibration method for additive manufacturing equipment, comprising:

[0005] The working chamber is heated until the temperature reaches the sintering temperature, and then stabilized for a certain period of time to allow the thermal deformation of the additive manufacturing equipment to stabilize.

[0006] Multiple fixtures are placed in the laser overlap area of ​​the working cavity, and data acquisition components are provided on the fixtures; the number of fixtures increases according to the number of lasers in the additive manufacturing equipment.

[0007] Start the fixture and cool the data acquisition unit;

[0008] Adjust the top surface of the data acquisition component to coincide with the actual sintering surface;

[0009] Laser beams are used to scan the pattern required for calibrating the overlap at the overlap location;

[0010] The above pattern was photographed, and the pattern analysis was performed to determine the calibrated galvanometer control.

[0011] Optionally, the step of photographing the above pattern, performing pattern analysis, and determining the calibrated galvanometer control includes:

[0012] The above pattern was photographed using an electron microscope;

[0013] The photographed pattern is measured using software that comes with an electron microscope. By processing the deviation data of the laser and laser overlap areas at two or more locations along a line of overlap, the error of each laser overlap is manually calculated.

[0014] Write the above errors into the corresponding file or software for controlling the galvanometer.

[0015] Optionally, the step of photographing the above pattern, performing pattern analysis, and determining the calibrated galvanometer control includes:

[0016] Take a picture of the above pattern using an electron microscope or camera;

[0017] The above-mentioned photographed pattern data is measured in the software of the automatic calculation platform to calculate the angle, translation and scaling data required for each laser.

[0018] The software of the aforementioned automatic calculation platform automatically modifies and writes the corresponding galvanometer control file according to the angle, translation and scaling data required for each laser, thus obtaining a new galvanometer control file;

[0019] Replace the original galvanometer control file with the new one.

[0020] Optionally, heating the working chamber until the temperature reaches the sintering temperature and then stabilizing it for a certain period of time to allow the thermal deformation of the additive manufacturing equipment to stabilize includes:

[0021] Place the tooling equipped with data acquisition components into the working chamber;

[0022] Light-emitting scanning lines are performed within time intervals to scan the overlap test lines on the data acquisition device, and the position of the overlap test lines is observed.

[0023] When the positions of the overlap test lines from the previous scan and the overlap test lines from the next scan coincide, the sintering temperature is considered to be stable.

[0024] Optionally, the data acquisition element is a blackened aluminum sheet.

[0025] Optionally, multiple tooling fixtures can be connected in series and then connected to a water chiller.

[0026] The present invention also provides an additive manufacturing apparatus and a laser overlap calibration method using the additive manufacturing apparatus.

[0027] The present invention also provides a tooling for a laser overlap calibration method applied to the additive manufacturing equipment, comprising:

[0028] Heat-resistant base, suitable for placement in the working chamber;

[0029] A water-cooled structure is provided on the heat-resistant base; a water-cooled flow channel is provided inside the water-cooled structure;

[0030] The data acquisition component is mounted on the top surface of the water-cooled structure.

[0031] Optionally, the heat-resistant base is made of phenolic plastic.

[0032] Optionally, a heat insulation element is provided between the heat-resistant base and the water-cooled structure.

[0033] The technical solution of the present invention has the following advantages compared with the prior art:

[0034] 1. The laser overlap calibration method for additive manufacturing equipment provided by this invention includes: heating the working cavity until the temperature reaches the sintering temperature, stabilizing it for a certain period of time to stabilize the thermal deformation of the additive manufacturing equipment; placing multiple fixtures in the laser overlap area of ​​the working cavity, with data acquisition components mounted on the fixtures; the number of fixtures increases according to the number of lasers in the additive manufacturing equipment; starting the fixtures and cooling the data acquisition components; adjusting the top surface of the data acquisition components to coincide with the actual sintering surface; using laser beam emission to scan the pattern required for calibration overlap at the overlap position; photographing the pattern, performing pattern analysis, and determining the galvanometer control after calibration. Because the sintering temperature is much higher than room temperature, mechanical structural components will undergo significant deformation, resulting in a large deviation between the laser calibration overlap at room temperature and the actual sintering overlap. This leads to poor laser overlap calibration results, making it impossible to effectively analyze and calculate the direction and magnitude of structural deformation. Finite element analysis is complex, and the deformation varies with each installation torque, requiring multiple searches for compensation values ​​generated by deformation for laser overlap calibration. This application's technical solution first simulates a sintering process to stabilize the deformation of mechanical structural components before collecting overlap calibration data, significantly improving the accuracy and efficiency of laser overlap calibration. Furthermore, it uses tooling to suppress the temperature of the data acquisition components, preventing overheating and deformation within the cavity, thus obtaining accurate data. These methods effectively counteract the impact of irregular deformation caused by temperature rise on laser overlap calibration, improving calibration efficiency and the success rate of a single calibration attempt.

[0035] 2. The pattern photographing, pattern analysis, and determination of calibrated galvanometer control in the present invention include: photographing the above-mentioned pattern using an electron microscope; measuring the photographed pattern using the software supporting the electron microscope, processing the deviation data of the laser and laser overlapping area through the data at two or more positions on a lap joint line, and manually calculating the error existing in each laser lap joint; writing the above-mentioned error into the corresponding file or software for controlling the galvanometer; adopting the above technical solution in this application is applicable to the situation where the number of lasers is small, and manual calculation can be directly performed on the software supporting the electron microscope without the need to equip an automatic calculation platform, with lower cost.

[0036] 3. The pattern photographing, pattern analysis, and determination of calibrated galvanometer control in the present invention include: photographing the above-mentioned pattern using an electron microscope or a camera; measuring the data of the photographed pattern in the software of an automatic calculation platform to calculate the angle, translation, and scaling data that each laser needs to offset; the software of the automatic calculation platform automatically modifies and writes the corresponding galvanometer control file according to the angle, translation, and scaling data that each laser needs to offset to obtain a new galvanometer control file; replacing the original galvanometer control file with the new galvanometer control file; adopting the above technical solution in this application is applicable to the situation where the number of lasers is large and the calculation amount is complex, and the above calculation amount is completed by equipping an automatic calculation platform and the corresponding software.

[0037] 4. The heating of the working chamber until the temperature reaches the sintering temperature and then stabilizing for a certain period to make the thermal deformation of the additive manufacturing equipment reach stability in the present invention includes: putting the tooling equipped with a data acquisition component into the working chamber; performing light output scanning lines at time intervals to scan lap joint test lines on the data acquisition component and observing the positions of the lap joint test lines; when the positions of the lap joint test lines scanned last time and the lap joint test lines scanned next time coincide, it is determined that the sintering temperature is stable; adopting the above technical solution in this application can simply and conveniently determine the time point when the heating reaches deformation stability.

[0038] The data acquisition component in the present invention is an aluminum sheet treated by blackening; adopting the above technical solution in this application can conveniently determine the stable state and perform laser lap joint calibration through the aluminum sheet.

[0039] 6. Multiple toolings in the present invention are suitable for being connected in series and then connected to a water chiller; adopting the above technical solution in this application can centrally control the cooling state of the tooling through one water chiller, ensure the cooling effect, and reduce the cost.

[0040] 7. The additive manufacturing equipment provided by the present invention applies the laser lap joint calibration method of the additive manufacturing equipment; the technical solution of this application can improve the laser lap joint calibration efficiency and the success rate of one-time calibration of the additive manufacturing equipment by adopting the laser lap joint calibration method of the additive manufacturing equipment.

[0041] 8. The tooling provided by the present invention is applied to the laser overlap calibration method of the additive manufacturing equipment, comprising: a heat-resistant base suitable for placement in the working cavity; a water-cooling structure disposed on the heat-resistant base; a water-cooling channel provided in the water-cooling structure; and a data acquisition component disposed on the top surface of the water-cooling structure. The present application adopts the above technical solution to prevent the data acquisition component from undergoing thermal deformation, which would affect the laser overlap calibration and ensure the accuracy of data acquisition.

[0042] 9. The heat-resistant base of the present invention is made of phenolic plastic; the above technical solution adopted in this application not only provides heat resistance but is also easy to process.

[0043] 10. The present invention provides a heat insulation component between the heat-resistant base and the water-cooled structure; the present application adopts the above technical solution to prevent the temperature of the contact surface from rising too quickly. Attached Figure Description

[0044] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0045] Figure 1 This is a schematic diagram of the process steps of the laser overlap calibration method for additive manufacturing equipment provided in the embodiments of the present invention;

[0046] Figure 2 This is a side view of the tooling provided in an embodiment of the present invention.

[0047] Figure 3 This is a top view of the heat-resistant base provided in an embodiment of the present invention.

[0048] Figure 4 This is a side view of the heat-resistant base provided in an embodiment of the present invention.

[0049] Figure 5 This is a top view of the aluminum sheet provided in an embodiment of the present invention.

[0050] Figure 6 This is a side view of the aluminum sheet provided in an embodiment of the present invention.

[0051] Figure 7 This is a top view of the structure of the heat insulation component provided in an embodiment of the present invention;

[0052] Figure 8This is a side view of the thermal insulation component provided in an embodiment of the present invention.

[0053] Figure 9 This is a top view schematic diagram of the water-cooling structure provided in the embodiment of the present invention;

[0054] Figure 10 This is a side view of the water-cooling structure provided in an embodiment of the present invention. Figure 1 ;

[0055] Figure 11 This is a side view of the water-cooling structure provided in an embodiment of the present invention. Figure 2 ;

[0056] Figure 12 This is a schematic diagram showing the arrangement of multiple tooling fixtures in the working chamber according to an embodiment of the present invention.

[0057] Explanation of reference numerals in the attached figures:

[0058] 1. Water-cooled structure; 2. Water inlet; 3. Water outlet; 4. Water-cooled flow channel; 5. Water inlet connector; 6. Water outlet connector; 7. Heat-resistant base; 8. Heat insulation component; 9. Aluminum sheet; 10. Fasteners. Detailed Implementation

[0059] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0060] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0061] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0062] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0063] like Figure 1 , Figure 5 , Figure 6 and Figure 12 One specific embodiment of the laser overlap calibration method for the additive manufacturing equipment shown includes the following steps:

[0064] S1. Heat the working chamber until it reaches the sintering temperature, then stabilize it for a certain period of time to allow the thermal deformation of the additive manufacturing equipment to stabilize. Generally, it stabilizes about 2 hours after the temperature reaches the sintering temperature. The time will vary depending on the material of the working chamber. Specifically, the working chamber can be heated by the additive manufacturing equipment or by external devices.

[0065] The specific steps of step S1 are as follows:

[0066] S11. Place the fixture equipped with the data acquisition component into the working chamber; specifically, the data acquisition component is a blackened aluminum sheet 9, such as... Figure 5 and Figure 6 As shown.

[0067] S12. Perform light-emitting scanning lines in time intervals to scan the overlap test lines on the data acquisition device and observe the position of the overlap test lines; specifically, an electronic magnifying glass can be used to observe the position of the overlap test lines.

[0068] S13. When the positions of the overlap test lines from the previous scan and the next scan coincide, the sintering temperature is considered stable. The heating stabilization time of the additive manufacturing equipment can be recorded. When sintering is performed again using the same equipment and at the same temperature, the recorded time can be used directly without needing to perform a stability assessment again.

[0069] S2, such as Figure 12As shown, multiple tooling fixtures equipped with data acquisition components are placed in the laser overlap area of ​​the working cavity. There can be three or more tooling fixtures, specifically five tooling fixtures. The number of tooling fixtures increases according to the number of lasers in the additive manufacturing equipment. Generally, one or two tooling fixtures are placed on the overlap laser and the laser overlap line. Furthermore, multiple tooling fixtures are suitable for being connected in series and then connected to the water chiller.

[0070] S3. Start the tooling and cool the data acquisition unit; specifically, turn on the water chiller, set the temperature to about 23-25℃, and after the water chiller has been running normally for about 5 minutes, you can proceed with the subsequent steps.

[0071] S4. Adjust the top surface of the data acquisition component to coincide with the actual sintering surface. Specifically, the top surface of the data acquisition component can be adjusted to coincide with the actual sintering surface using high-temperature resistant instruments or tooling such as a high-temperature resistant dial indicator. The higher the degree of coincidence between the top surface of the data acquisition component and the actual sintering surface, the more accurate the data collected will be.

[0072] S5. Use laser beam to scan the pattern required for calibrating the overlap at the overlap position;

[0073] S6. Take a picture of the above pattern, perform pattern analysis, and determine the calibrated galvanometer control.

[0074] When the number of lasers is small, step S6 specifically adopts the following steps:

[0075] S611. Take a picture of the above pattern using an electron microscope;

[0076] S612. Use the software accompanying the electron microscope to measure the photographed pattern, and process the deviation data of the laser and laser overlap area by data from two or more positions on a line of overlap, and manually calculate the error of each laser overlap; the error includes: angle error, scaling error, translation error, etc.

[0077] S613. Write the above errors into the corresponding file or software for controlling the galvanometer.

[0078] When the number of lasers is large, step S7 specifically adopts the following steps:

[0079] S621. Take a picture of the above pattern using an electron microscope or camera;

[0080] S622. The above-mentioned photographed pattern data is measured in the software of the automatic calculation platform to calculate the angle, translation and scaling data required for each laser.

[0081] S623. The software of the above automatic calculation platform automatically modifies and writes the corresponding galvanometer control file according to the angle, translation, and scaling data that each laser needs to offset, and obtains a new galvanometer control file.

[0082] S624. Replace the original galvanometer control file with the new galvanometer control file.

[0083] After the laser lap calibration is basically completed, the sintering verification of the lap package can be carried out.

[0084] The present invention also provides an additive manufacturing device, which applies the laser lap calibration method of the additive manufacturing device. Specifically, the additive manufacturing device can be a selective laser sintering device.

[0085] As Figures 2 to 12 A specific embodiment of the tooling shown includes: a heat-resistant base 7 placed in the working chamber, a water-cooling structure 1 provided on the heat-resistant base 7, and a data acquisition component provided on the top surface of the water-cooling structure ¹.

[0086] As Figure 2 , Figures 9 to 12 Shown, a water-cooling channel 4 is provided in the water-cooling structure 1; the water-cooling channel 4 is in a "ji" - shaped circulation form; water inlets 2 and outlets 3 are respectively provided at both ends of the water-cooling channel 4; a water inlet joint 5 is installed on the water inlet 2, and a water outlet joint 6 is installed on the water outlet 3. The water-cooling structure 1 is square, and protruding ear seats are provided on each side of the water-cooling structure 1. The ear seats are connected to the heat-resistant base 7 through fasteners 10. Specifically, the fasteners 10 are bolts, which can be bolts of M8×30. The top surface of the water-cooling structure 1 is suitable for placing a data acquisition component.

[0087] As Figure 3 And Figure 4 Shown, the material of the heat-resistant base 7 is phenolic plastic.

[0088] As Figure 2 , Figure 7 And Figure 8 Shown, an insulating member 8 is provided between the heat-resistant base 7 and the water-cooling structure 1. The insulating member 8 is an asbestos board. Specifically, a first groove is provided on the top surface of the heat-resistant base 7. The insulating member 8 is adapted to the shape of the first groove, and the insulating member 8 is placed in the first groove. The thickness of the insulating member 8 is the same as the depth of the first groove.

[0089] As Figure 5 And Figure 6 Shown, specifically, the data acquisition component is an aluminum sheet 9 subjected to blackening treatment.

[0090] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A laser overlap calibration method for additive manufacturing equipment, characterized in that, include: The working chamber is heated until the temperature reaches the sintering temperature, and then stabilized for a certain period of time to allow the thermal deformation of the additive manufacturing equipment to stabilize. Multiple fixtures are placed in the laser overlap area of ​​the working cavity, and data acquisition components are provided on the fixtures; the number of fixtures increases according to the number of lasers in the additive manufacturing equipment. Start the fixture and cool the data acquisition unit; Adjust the top surface of the data acquisition component to coincide with the actual sintering surface; Laser beams are used to scan the pattern required for calibrating the overlap at the overlap location; Take pictures of the above patterns, perform pattern analysis, and determine the calibrated galvanometer control; The heating of the working chamber until the temperature reaches the sintering temperature, followed by stabilization for a certain period of time to allow the thermal deformation of the additive manufacturing equipment to stabilize, includes: Place the tooling equipped with data acquisition components into the working chamber; Light-emitting scanning lines are performed within time intervals to scan the overlap test lines on the data acquisition device, and the position of the overlap test lines is observed. When the positions of the overlap test lines from the previous scan and the overlap test lines from the next scan coincide, the sintering temperature is considered to be stable. When the number of lasers is small, the process of photographing the above pattern, performing pattern analysis, and determining the calibrated galvanometer control includes: The above pattern was photographed using an electron microscope; The photographed pattern is measured using software accompanying the electron microscope. By processing the deviation data of the laser and laser overlap areas at two or more locations along an overlap line, the error of each laser overlap is manually calculated. The error includes: angle error, scaling error, and translation error. Write the above errors into the corresponding file or software for controlling the galvanometer; When there are a large number of lasers, the process of photographing the above pattern, performing pattern analysis, and determining the calibrated galvanometer control includes: Take a picture of the above pattern using an electron microscope or camera; The above-mentioned photographed pattern data is measured in the software of the automatic calculation platform to calculate the angle, translation and scaling data required for each laser. The software of the aforementioned automatic calculation platform automatically modifies and writes the corresponding galvanometer control file according to the angle, translation and scaling data required for each laser, thus obtaining a new galvanometer control file; Replace the original galvanometer control file with the new one.

2. The laser overlap calibration method for additive manufacturing equipment according to claim 1, characterized in that, The data acquisition component is a blackened aluminum sheet (9).

3. The laser overlap calibration method for additive manufacturing equipment according to claim 1, characterized in that, Multiple tooling fixtures are suitable for being connected in series before being connected to a water chiller.

4. An additive manufacturing apparatus, characterized in that, A laser overlap calibration method for additive manufacturing equipment according to any one of claims 1-3.

5. A tooling fixture applied to a laser overlap calibration method for an additive manufacturing equipment according to any one of claims 1-3, characterized in that, include: A heat-resistant base (7) is suitable for placement in the working chamber; A water-cooled structure (1) is disposed on the heat-resistant base (7); A water-cooling channel (4) is provided inside the water-cooling structure (1); The data acquisition component is located on the top surface of the water-cooled structure (1).

6. The tooling according to claim 5, characterized in that, The heat-resistant base (7) is made of phenolic plastic.

7. The tooling according to claim 5 or 6, characterized in that, A heat insulation element (8) is provided between the heat-resistant base (7) and the water-cooled structure (1).

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