3D printing equipment protection glass pollution detection and cleaning method and system

Abstract

The invention discloses a pollution detection and cleaning method and system for 3D printing equipment protection glasses. The initial position of a sliding table is located at a cabin side edge avoiding position and is far away from a printing work area; in the pollution detection and cleaning period, the sliding table moves to the position under all the protective glasses along a preset path, whether the whole-process task of detection and cleaning can be completed in the powder laying time window or not is confirmed at the maximum allowable speed of the sliding table, if yes, pollution detection and cleaning are conducted at the same time, and if not, only photographing is conducted, and cleaning is not conducted. And positioning and cleaning are carried out after the next powder laying signal. According to online synchronous detection, pollution detection is automatically conducted on the protective glass in the powder laying or printing process, and shutdown is not needed; automatic cleaning: triggering a cleaning program based on the pollution degree to reduce manual intervention; according to the non-interference design, it is ensured that the detecting and cleaning device is completely separated from a printing area when not working through a movable sliding table avoiding mechanism, and influences on normal printing work are avoided.

Description

Technical Field

[0001] This invention belongs to the field of additive manufacturing technology, and in particular relates to a method and system for detecting and cleaning contamination in protective mirrors of 3D printing equipment. Background Technology

[0002] Selective Laser Melting (SLM) is a widely used and mature process. Based on the fundamental principles of rapid prototyping, this method employs a layer-by-layer additive manufacturing approach. According to the three-dimensional model of the part, the model is sliced ​​into layers of a specific thickness. Then, under the control of a CNC system, a laser, guided by a galvanometer, melts the metal powder, directly forming a part with a specific geometry. During SLM forming, the metal powder completely melts, resulting in a metallurgical bond. The formed parts exhibit high density and excellent microstructure, and it can also form high-precision, complex, and irregularly shaped metal parts.

[0003] In 3D printing equipment, protective mirrors are used to prevent dust, fumes, or molten material splatter from contaminating optical components. Currently, contamination detection and cleaning of protective mirrors mainly rely on regular manual inspection and maintenance, but the following specific problems still exist: (1) Untimely detection: Operators need to stop the machine and open the printing chamber for visual inspection. They cannot monitor the contamination status of the protective mirror in real time during the printing process, which may lead to the accumulation of contamination and printing defects, resulting in rough surface, structural distortion or printing failure of the printed parts.

[0004] (2) Interference with the printing process: Traditional fixed detection devices occupy the printing work area, affecting toner application or printhead movement, resulting in a decrease in printing accuracy. Summary of the Invention

[0005] To overcome the problems existing in the prior art, this invention proposes a method and system for detecting and cleaning contamination of protective mirrors in 3D printing equipment. This invention achieves online synchronous detection: automatically detecting contamination of the protective mirror during powder spreading or printing without stopping the machine; automatic cleaning: triggering the cleaning program based on the degree of contamination, reducing manual intervention; and interference-free design: ensuring that the detection and cleaning device is completely removed from the printing area when not in operation through a moving slide avoidance mechanism, avoiding any impact on normal printing operations.

[0006] This invention is implemented as follows: a method for detecting and cleaning contamination in the protective mirror of a 3D printing device, comprising the following steps: After the equipment is started, the positions of each protective mirror and the clearance position of the slide are imported into the control system. The control system moves the slide to the side clearance position closest to the first protective mirror and sets the number of the protective mirror to be tested to N=1. The control system enters standby mode and waits for the "start toner spreading" signal from the printer host. After receiving the "start toner spreading" signal, the control system immediately sets to working mode. The visual inspection camera for detecting contamination of the protective mirror and the cleaning nozzle are both installed on the slide. The slide is located above the printing work area in the chamber and can move linearly along the XY plane. Set the following parameters: T_available: The available time window for a single application of powder; T_inspect: Fixed time consumption for visual inspection, including image capture and image analysis; T_clean: Time taken for air cleaning when cleaning is required; V_required: The average positioning speed required for the slide to reach the protective mirror N within a specified time; Based on the powder spreading distance D1 and the powder spreading speed V1, the available time window for a single powder spreading operation is calculated: T_available=2D1 / V1; Calculate the required average positioning speed V_required based on the distance D2 from the slide table to the nearest protective mirror from one side of the clearance position and the distance D_x from the slide table to the other side of the clearance position: If the clearance position of the next protective mirror N+1 to be tested is on the same side as the clearance position of the current protective mirror N to be tested, the sliding table needs to be positioned by a distance of 2D2 along the Y-axis, and V_required=2D2 / (T_available - T_inspect - T_clean); If the clearance position of the next protective mirror N+1 to be tested is not on the same side as the clearance position of the current protective mirror N to be tested, the slide needs to be positioned along the Y-axis by a distance of D_x, and V_required = D_x / (T_available - T_inspect - T_clean); Compare the values ​​of V_required and the maximum allowable speed of the slide, V_max: If V_required≤V_max, the entire "detection + cleaning" process can be completed within the current toner application time window. The slide moves to below the protective mirror N at a speed of V_required, performs image taking and analysis, and determines whether contamination exists based on the analysis results. If there is no contamination, the protective mirror N is marked as clean, and the protective mirror to be tested is set to N=N+1. If contamination exists, the cleaning process is performed immediately. After cleaning, the protective mirror number N remains unchanged, and the next toner application signal is used to take another image to confirm whether the contamination has been cleaned. If V_required > V_max, the entire "detection + cleaning" process cannot be completed within the current toner application time window. The system executes a fast detection mode, with the slide moving at V_max speed to below the protective mirror N and immediately taking a picture. After taking the picture, the slide immediately returns to the avoidance position. Image analysis is performed in parallel with the slide's return movement. The analysis results determine whether contamination exists. If there is no contamination, the protective mirror N is marked as clean, and the protective mirror to be tested N = N+1 is set. If contamination exists, the protective mirror N is marked as needing cleaning, and the protective mirror number N remains unchanged. Cleaning is not performed this time, and the system waits for the next toner application signal to perform positioning and cleaning. After cleaning, the protective mirror number N remains unchanged, and the system takes another picture to confirm whether the contamination has been cleaned during the next toner application signal.

[0007] In the above technical solution, preferably, the visual inspection camera captures an image of the protective mirror surface during the photo taking process, and the image processing unit calculates the proportion of the contaminated area based on the gray value during the image analysis.

[0008] In the above technical solutions, preferably, a pollution level ≤3% is recorded as no pollution, and a pollution level >3% is recorded as pollution present.

[0009] In the above technical solution, a further preferred embodiment is that if 3% < pollution level ≤ 5%: it is determined to be light pollution, and a single pulse air blowing cleaning is initiated; if the pollution level > 5%: it is determined to be heavy pollution, and multiple pulse air blowing cleaning is initiated.

[0010] In the above technical solution, preferably, after each test, the degree of contamination and the number of cleaning times of the protective mirror are recorded; Historical pollution level array: C_i=[ , ,...] Historical cleaning counts: clean_count_i Average contamination level: avg_contamination_i

[0011] Cleaning frequency: frequency_i = clean_count_i / T, where T is the total running time; Average pollution level threshold: Th1 Cleaning frequency threshold: Th2 Based on historical data, the average level of contamination and cleaning frequency for each protective mirror were calculated; If avg_contamination_i > Th1 or frequency_i > Th2, then the protective mirror is marked as an easily contaminated protective mirror. After completing one round of cyclic testing, the easily contaminated protective mirror is tested separately.

[0012] In the above technical solution, preferably, regardless of what operation is performed in this task, at the end of the current powder spreading cycle, the slide must return to the preset avoidance position, the control system updates the status, wait for the next "start powder spreading" signal, and start a new round of process.

[0013] In the above technical solution, preferably, when N exceeds the total number of protective mirrors, N is reset to 1, and a new round of cyclic detection begins.

[0014] A 3D printing equipment protective mirror contamination detection and cleaning system includes a moving slide module, a vision inspection module, an air blowing cleaning module, and a control system; The movable slide module communicates with the main controller of the printing equipment and receives movement commands. The movable slide module includes an X-axis linear guide rail, a Y-axis linear guide rail, a slide, and a drive motor. The two Y-axis linear guide rails are arranged along the Y-axis and fixed to the side wall of the printing chamber by bolts. The X-axis linear guide rail is arranged along the X-axis between the two Y-axis linear guide rails. The slide is set on the X-axis linear guide rail. The X-axis linear guide rail and the Y-axis linear guide rail are controlled by drive motors respectively, so that the slide can move linearly along the XY plane. Visual inspection module: includes a high-resolution visual inspection camera, which is fixed on the slide by a mounting bracket. The lens of the visual inspection camera is parallel to the surface of the protective lens. The visual inspection camera is connected to the control system via a data cable. Air blowing cleaning module: includes nozzle, solenoid valve and air pipe. The nozzle is fixed on the slide by bracket and installed in parallel with the vision inspection module. The air inlet end of the nozzle is connected to the air pipe, which is connected to an external compressed argon gas source. A solenoid valve is installed on the air pipe, and the solenoid valve is controlled by the control system to open and close.

[0015] In the above technical solution, preferably, the drive motor controls the X-axis linear guide rail and Y-axis linear guide rail to work through a lead screw or belt drive, thereby moving the slide table and in turn moving the vision inspection module and the air blowing cleaning module.

[0016] In the above technical solution, preferably, the visual inspection module further includes an LED lighting system, which includes multiple LED lights, each of which is evenly distributed and installed around the camera to ensure that the light shines perpendicularly onto the surface of the protective mirror.

[0017] The advantages and positive effects of this invention are: 1) The protective mirror contamination detection and cleaning system of the present invention is integrated into the 3D printing equipment chamber. It is an automated system with a tight combination of electrical control and actuator. Each module works together through mechanical connection and electrical control to realize online detection and cleaning of the protective mirror. It mainly includes a moving slide module, a vision detection module and an air blowing cleaning module. Through the cooperation of slide positioning, vision detection and pneumatic cleaning, the detection and cleaning of the protective mirror can be completed within a specific time window of the printing process according to the predetermined workflow.

[0018] 2) The mobile slide module of the present invention can automatically reset to a dedicated avoidance position on the side of the printing chamber during non-working periods through the slide avoidance design, realizing physical isolation between the detection and cleaning device and the printing work area, fundamentally eliminating any risk of interference to the movement trajectory of the powder spreader and the laser scanning path.

[0019] 3) The working sequence of this invention is electrically synchronized with the powder laying stage of the 3D printing equipment. Within the strict time limit (powder laying cycle), the working strategy is intelligently adjusted to maximize the completion of automatic maintenance tasks without affecting the core printing operation.

[0020] 4) The air-blowing cleaning function of the present invention uses compressed inert gas (argon) as the cleaning medium, and manages the blowing time and pressure through a precisely controlled solenoid valve, thereby achieving a non-contact, residue-free cleaning effect.

[0021] 5) This invention improves print quality and consistency: Through real-time monitoring and timely cleaning, it effectively avoids laser energy attenuation and focus drift caused by protective lens contamination, reducing print failure rate and material loss due to lens contamination; it significantly improves overall equipment efficiency: It achieves full automation and zero downtime in the maintenance process, reducing equipment downtime for maintenance and increasing effective production time; it reduces operating costs: Automated operation reduces the frequency of manual intervention and the professional skill requirements, thus reducing maintenance costs. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the overall system structure (top view of the cabin) provided in an embodiment of the present invention. Figure 2 This is a partial enlarged view of the slide base provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the avoidance position of the next protective mirror N+1 to be tested and the avoidance position of the current protective mirror N to be tested, provided in an embodiment of the present invention. Figure 4 This is a schematic diagram of the avoidance position of the next protective mirror N+1 to be tested and the avoidance position of the current protective mirror N to be tested, provided in an embodiment of the present invention.

[0023] In the diagram: 1. X-axis linear guide rail; 2. Y-axis linear guide rail; 3. Visual inspection camera; 4. First LED light; 5. Second LED light; 6. Third LED light; 7. Fourth LED light; 8. First clearance position; 9. Second clearance position; 10. First protective mirror; 11. Second protective mirror; 12. Third protective mirror; 13. Fourth protective mirror; 14. Slide table; 15. Solenoid valve; 16. Nozzle; 17. Air pipe. Detailed Implementation

[0024] To further understand the content, features, and effects of this invention, the following embodiments are provided, and detailed descriptions are given below in conjunction with the accompanying drawings: To facilitate a clear description of the technical solutions in the embodiments of the present invention, it should be noted that in the embodiments of the present invention, the terms "first" and "second" are used to distinguish identical or similar items with essentially the same function and effect. For example, the first threshold and the second threshold are merely used to distinguish different thresholds and do not limit their order. Those skilled in the art will understand that the terms "first" and "second" do not limit the quantity or execution order, and the terms "first" and "second" are not necessarily different.

[0025] It should be noted that in this invention, the terms "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary" or "for example" in this invention should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of terms such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0026] In this invention, "at least one" refers to one or more, and "more than one" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c can represent: a, b, c, a combination of a and b, a combination of a and c, a combination of b and c, or a, b, and c, where a, b, and c can be single or multiple.

[0027] The top of the 3D printing equipment chamber is equipped with four protective mirrors, namely the first protective mirror 10, the second protective mirror 11, the third protective mirror 12, and the fourth protective mirror 13.

[0028] Please see Figures 1-3This invention provides a method for detecting and cleaning contamination in the protective mirror of a 3D printing device, comprising the following steps: After the equipment is started, the positions of each protective mirror and the clearance positions of the slide are imported into the control system. The control system controls the slide to move to the side clearance position closest to the first protective mirror (the two clearance positions are located at both ends of the Y-axis, namely the first clearance position 8 and the second clearance position 9). The number of the protective mirror to be tested is set to N=1. The control system enters the standby state and waits for the "start toner spreading" signal from the printing host. After receiving the "start toner spreading" signal, the control system immediately sets to the working state. Among them, the visual inspection camera 3 for detecting contamination of the protective mirror and the nozzle 16 for cleaning are both installed on the slide 14. The slide 14 is located above the printing working area of ​​the chamber and can move linearly along the XY plane.

[0029] Set the following parameters: T_available: The available time window for a single application of powder; T_inspect: Fixed time consumption for visual inspection, including image capture and image analysis; T_clean: Time taken for air cleaning when cleaning is required; V_required: The average positioning speed required for slide 14 to reach protective mirror N within a specified time; Based on the powder spreading distance D1 and the powder spreading speed V1, the available time window for a single powder spreading operation is calculated: T_available=2D1 / V1; Calculate the required average positioning speed V_required based on the distance D2 from the slide table to the nearest protective mirror from one side of the clearance position and the distance D_x from the slide table to the other side of the clearance position: If the clearance position of the next protective mirror N+1 to be tested is on the same side as the clearance position of the current protective mirror N to be tested, the slide 14 needs to be positioned along the Y-axis by a distance of 2D2, and V_required=2D2 / (T_available - T_inspect - T_clean); If the clearance position of the next protective mirror N+1 to be tested is not on the same side as the clearance position of the current protective mirror N to be tested, the slide 14 needs to be positioned by a distance D_x along the Y-axis, and V_required = D_x / (T_available - T_inspect - T_clean).

[0030] Compare V_required with the maximum allowable speed V_max of slide 14: Scenario A (Normal): If V_required ≤ V_max, the entire "detection + cleaning" process can be completed within the current toner application time window, and the task is feasible within the time window. The slide 14 moves to below the protective mirror N at a speed of V_required (or an optimized speed curve), performs image taking and analysis, and determines whether contamination exists based on the analysis results. If there is no contamination (contamination level ≤ 3%): mark the protective mirror N as clean and set the protective mirror to be tested N = N + 1; if there is contamination (contamination level > 3%): immediately perform cleaning. After cleaning, the protective mirror number N remains unchanged for re-inspection next time, and the next toner application signal is used to take another image to confirm whether the contamination has been cleaned.

[0031] Scenario B (Time-sensitive): If V_required > V_max, the entire "detection + cleaning" process cannot be completed within the current toner application window. The system executes a rapid detection mode, with slide 14 moving at V_max speed to below protective mirror N and immediately taking a picture. After taking the picture, slide 14 does not stop but immediately returns to the avoidance position. Image analysis is performed in parallel with the return movement of slide 14, and the analysis results determine whether contamination exists. If there is no contamination (contamination level ≤ 3%): Protective mirror N is marked as clean, and the protective mirror to be tested N = N + 1 is set. If there is contamination (contamination level > 3%): Protective mirror N is marked as needing cleaning, and the protective mirror number N remains unchanged. Cleaning is not performed this time; the system waits for the next toner application signal to perform positioning and cleaning. After cleaning, the protective mirror number N remains unchanged, and the system takes another picture to confirm whether the contamination has been cleaned during the next toner application signal.

[0032] In a preferred embodiment, the visual inspection camera 3 captures images of the protective mirror surface during the photo taking process, and the image processing unit calculates the proportion of the contaminated area based on the grayscale value during the image analysis.

[0033] As a preferred embodiment, if 3% < contamination level ≤ 5%: it is determined to be light contamination, and a single pulse air blowing cleaning is initiated (the solenoid valve opens for 1 second). After cleaning, the protective mirror N to be tested remains unchanged so that it can be re-inspected next time.

[0034] If the contamination level is >5%, it is considered heavily contaminated. Initiate multiple pulse air cleaning cycles (the solenoid valve opens for 0.5 seconds, closes for 0.5 seconds, and repeats this cycle 3 times). After cleaning, the protective mirror N to be inspected remains unchanged for future re-inspection.

[0035] As a preferred embodiment, after each test, the degree of contamination and the number of cleaning cycles of the protective mirror are recorded; Historical pollution level array: C_i=[ , ,...] Historical cleaning counts: clean_count_i Average contamination level: avg_contamination_i

[0036] Cleaning frequency: frequency_i = clean_count_i / T, where T is the total running time; Average pollution level threshold: Th1 Cleaning frequency threshold: Th2 Based on historical data, calculate the average level of contamination and cleaning frequency (i.e., the number of times to clean per unit time) for each protective lens. If avg_contamination_i > Th1 or frequency_i > Th2, then the protective mirror is marked as an easily contaminated protective mirror, and after completing one round of cyclic testing, the easily contaminated protective mirror is tested separately.

[0037] In a preferred implementation, regardless of the operation performed in this task, at the end of the current powder spreading cycle, the slide table 14 must return to the preset avoidance position, the control system updates the status, wait for the next "start powder spreading" signal, and start a new round of process.

[0038] As a preferred implementation, when N exceeds the total number of protective mirrors, N is reset to 1, and a new round of cyclic detection begins.

[0039] A 3D printing equipment protective mirror contamination detection and cleaning system includes a moving slide module, a vision inspection module, an air blowing cleaning module, and a control system.

[0040] The movable slide module communicates with the main controller of the printing equipment and receives movement commands. The movable slide module includes an X-axis linear guide rail 1, a Y-axis linear guide rail 2, a slide 14, and a drive motor. The two Y-axis linear guide rails 2 are arranged along the Y-axis and fixed to the side wall of the printing chamber by bolts. The X-axis linear guide rail 1 is arranged along the X-axis between the two Y-axis linear guide rails 2. The slide 14 is set on the X-axis linear guide rail 1. The X-axis linear guide rail 1 and the Y-axis linear guide rail 2 are controlled by drive motors respectively, so that the slide 14 can move linearly along the XY plane.

[0041] Visual inspection module: includes a high-resolution visual inspection camera 3, which is fixed on the slide table 14 by a mounting bracket. The lens of the visual inspection camera 3 is parallel to the surface of the protective mirror, and the visual inspection camera 3 is connected to the control system via a data cable.

[0042] The air blowing cleaning module includes a nozzle 16, a solenoid valve 15, and an air pipe 17. The nozzle 16 is fixed on the slide table 14 by a bracket and installed in parallel with the vision inspection module. The air inlet end of the nozzle 16 is connected to the air pipe 17, and the air pipe 17 is connected to an external compressed argon gas source (pressure adjustable range 0.1-0.5MPa). The solenoid valve 15 is installed on the air pipe 17, and the solenoid valve 15 is controlled to open and close by the control system.

[0043] In a preferred embodiment, the drive motor controls the X-axis linear guide rail 1 and the Y-axis linear guide rail 2 to work through a lead screw or belt drive, thereby moving the slide table 14 and in turn moving the vision inspection module and the air blowing cleaning module.

[0044] In a preferred embodiment, the visual inspection module further includes an LED lighting system comprising multiple LED lights, each evenly distributed around the camera to ensure that light perpendicularly illuminates the surface of the protective lens. This embodiment uses four LED lights: a first LED light 4, a second LED light 5, a third LED light 6, and a fourth LED light 7.

[0045] The initial position of the moving slide module is located in a dedicated clearance position on the side of the chamber, away from the printing work area. During contamination detection and cleaning, the slide 14 moves along a predetermined path to directly under each protective mirror, ensuring that the lens of the vision inspection camera 3 is parallel to the surface of the protective mirror. The entire system has a compact structure, and the moving slide module uses lightweight materials to reduce inertia. The system is coordinated by the main controller of the printing equipment. During toner spreading, the slide 14 moves to under the protective mirror according to a preset program. The vision inspection module acquires images, and the image processing unit analyzes the degree of contamination based on grayscale values. If the contamination level exceeds a threshold, the air-blowing cleaning module is triggered to blow air. After cleaning, the slide 14 returns to its clearance position.

[0046] In summary, this invention effectively avoids laser energy attenuation and focus drift caused by protective lens contamination through real-time monitoring and timely cleaning, thereby reducing printing failure rate and material loss due to lens contamination; it achieves full automation and zero downtime in the maintenance process, reducing equipment downtime for maintenance and increasing effective production time; automated operation reduces the frequency of manual intervention and the professional skill requirements, thus lowering maintenance costs.

[0047] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention shall fall within the scope of the technical solution of the present invention.

Claims

1. A 3D printing equipment protection mirror contamination detection and cleaning method, characterized in that, The method comprises the following steps: After the device is started, the positions of the protective mirrors and the positions of the avoidance positions of the sliding table are introduced into the control system, the control system controls the sliding table to move to the avoidance position closest to the first protective mirror, sets the number of the protective mirror to be detected N=1, and enters a standby state to wait for a "start powdering" signal of the printing host; after the control system receives the "start powdering" signal, the control system is immediately set to a working state; wherein the vision detection camera for detecting the pollution of the protective mirror and the nozzle for cleaning are both installed on the sliding table, and the sliding table is located above the printing working area of the cabin and can move linearly along the X-Y plane; The following parameters are set: T_available: available time window of single powdering; T_inspect: fixed time consumption of vision detection, including photographing and image analysis; T_clean: time consumption of air blowing cleaning when cleaning is required; V_required: average positioning speed of the sliding table to the protective mirror N within a specified time; According to the powdering distance D1 and the powdering speed V1, the available time window of single powdering is calculated as follows: T_available=2D1 / V1; According to the distance D2 of the sliding table moving from one avoidance position to the closest protective mirror and the distance D_x of the sliding table moving from one avoidance position to the other avoidance position, the average positioning speed V_required is calculated as follows: If the avoidance position of the next protective mirror N+1 to be detected and the avoidance position of the current protective mirror N to be detected are on the same side, the sliding table needs to be positioned along the Y-axis direction by a distance of 2D2, and V_required=2D2 / (T_available-T_inspect-T_clean); If the avoidance position of the next protective mirror N+1 to be detected and the avoidance position of the current protective mirror N to be detected are not on the same side, the sliding table needs to be positioned along the Y-axis direction by a distance of D_x, and V_required=D_x / (T_available-T_inspect-T_clean); The size of V_required and the maximum allowable speed V_max of the sliding table are compared: If V_required≤V_max, the "detection + cleaning" whole process task can be completed within the powdering time window, the sliding table moves to the position below the protective mirror N at the speed V_required, performs photographing and image analysis, and judges whether there is pollution according to the analysis result; if there is no pollution, the protective mirror N is marked as clean, and the number of the protective mirror to be detected N is set to N+1; if there is pollution, cleaning is immediately performed, after the cleaning is completed, the number of the protective mirror to be detected N remains unchanged, and the next powdering signal again performs photographing to confirm whether the pollution has been cleaned. If V_required > V_max, the "detection + cleaning" full-process task cannot be completed in the current powder laying time window, the system executes the rapid detection mode, the slide table moves to the bottom of the protection mirror N at the speed of V_max, immediately executes the photographing operation, after the photographing is completed, the slide table returns to the avoidance position, and the image analysis is completed in parallel with the return movement of the slide table. According to the analysis result, it is judged whether there is pollution or not; if there is no pollution, the protection mirror N is marked as clean, and the detection protection mirror N is set as N+1; if there is pollution, the protection mirror N is marked as to be cleaned, and the detection protection mirror number N remains unchanged, the cleaning is not executed this time, and the positioning and cleaning are executed again in the next powder laying signal. After the cleaning is completed, the detection protection mirror number N remains unchanged, and the photographing is performed again in the next powder laying signal to confirm whether the pollution has been cleaned.

2. The 3D printing equipment protection mirror contamination detection and cleaning method of claim 1, wherein, The visual detection camera collects the surface image of the protection mirror during photographing, and the image analysis work calculates the pollution area ratio based on the gray value through the image processing unit.

3. The 3D printing equipment protection lens contamination detection and cleaning method of claim 1, wherein, Pollution degree ≤ 3% is recorded as no pollution, and pollution degree > 3% is recorded as existing pollution.

4. The 3D printing equipment protection mirror contamination detection and cleaning method of claim 3, wherein, If 3% < pollution degree ≤ 5%, it is determined as mild pollution, and single pulse air blowing cleaning is started; if pollution degree > 5%, it is determined as severe pollution, and multiple pulse air blowing cleaning is started.

5. The 3D printing equipment protection lens contamination detection and cleaning method of claim 1, wherein, After each detection, the pollution degree value and the cleaning times of the protection mirror are recorded; Historical pollution level array: C_i=[ , ,...] Historical cleaning times: clean_count_i Average contamination level: avg_contamination_i Cleaning frequency: frequency_i = clean_count_i / T, wherein T is the total running time; Average pollution degree threshold: Th1 Cleaning frequency threshold: Th2 According to the historical data, the average pollution degree and the cleaning frequency of each protection mirror are calculated; If avg_contamination_i > Th1 or frequency_i > Th2, the protection mirror is marked as a pollution-prone protection mirror, and the detection of the pollution-prone protection mirror is performed separately after one round of cycle detection.

6. The 3D printing equipment protection lens contamination detection and cleaning method of claim 1, wherein, Regardless of the operation performed by the current task, at the end of the current powder laying period, the slide table must return to the preset avoidance position, the control system updates the state, waits for the arrival of the next "start powder laying" signal, and starts a new round of process.

7. The 3D printing equipment protection lens contamination detection and cleaning method of claim 1, wherein, When N exceeds the total number of protection mirrors, reset N = 1, and start a new round of cycle detection.

8. A 3D printing equipment protection mirror contamination detection and cleaning system for implementing the method of any one of claims 1-7, characterized in that, It comprises a moving slide table module, a visual detection module, an air blowing cleaning module and a control system. The moving slide table module communicates with the main controller of the printing equipment, receives the moving instructions, and comprises an X-axis linear guide rail, a Y-axis linear guide rail, a slide table and a driving motor. The two Y-axis linear guide rails are arranged along the Y-axis and are fixed to the side wall of the printing cabin by bolts. The X-axis linear guide rail is arranged between the two Y-axis linear guide rails along the X-axis. The slide table is arranged on the X-axis linear guide rail. The X-axis linear guide rail and the Y-axis linear guide rail are controlled by the driving motor respectively, so that the slide table can move linearly along the X-Y plane. The visual detection module comprises a high-resolution visual detection camera. The visual detection camera is fixed to the slide table through a mounting bracket. The lens of the visual detection camera is parallel to the surface of the protection mirror. The visual detection camera is connected to the control system through a data line. The blowing cleaning module comprises a nozzle, an electromagnetic valve and an air pipe, the nozzle is fixed on the sliding table through a support and is installed side by side with the visual detection module, the air inlet end of the nozzle is connected with the air pipe, the air pipe is connected with an external compressed argon source, the electromagnetic valve is arranged on the air pipe and is controlled to be opened and closed by the control system.

9. The 3D printing equipment protection lens contamination detection and cleaning method of claim 8, wherein, The driving motor controls the X-axis linear guide rail and the Y-axis linear guide rail to work through a lead screw or a belt drive, drives the sliding table to move, and then drives the visual detection module and the blowing cleaning module to move.

10. The 3D printing equipment protection lens contamination detection and cleaning method of claim 8, wherein, The visual detection module further comprises an LED lighting system, the LED lighting system comprises a plurality of LED lighting lamps, and each LED lighting lamp is uniformly installed around the camera to ensure that the light vertically irradiates the surface of the protection mirror.

Images