Multi-spot laser quenching head and control method thereof

Abstract

The present application relates to the technical field of laser surface heat treatment equipment, and discloses a multi-spot laser quenching head, which comprises a laser input assembly, a beam distribution assembly and an adjusting assembly, the laser input assembly is used for guiding incident laser, the beam distribution assembly comprises a plurality of beam deflection units located in the same incident laser coverage range, the adjusting assembly is connected with each beam deflection unit and used for adjusting the outgoing direction of the beam deflection unit, the plurality of beam deflection units are divided into one or more deflection groups according to the outgoing direction, each deflection group guides corresponding sub-beams to the same target light collection area, and the target light collection areas of different deflection groups are separated from each other, so that one or more quenching spots are formed on the workpiece surface, and the present application can form multiple quenching spots by using the same incident laser, thereby adapting to the synchronous laser quenching demand of multiple areas.

Description

Technical Field

[0001] This invention relates to the field of laser surface heat treatment equipment technology, and in particular to a multi-spot laser quenching head and its control method. Background Technology

[0002] Laser hardening utilizes a high-energy-density laser beam to rapidly heat the surface of a metal workpiece, raising the surface material to above its phase transition temperature. The material is then rapidly cooled via heat conduction from the workpiece substrate to form a hardened layer. This process features a small heat-affected zone, minimal deformation, and easy control over the location of the hardened layer, making it suitable for gears, guide rails, molds, and other parts requiring localized strengthening.

[0003] When there are two or more adjacent areas to be quenched on the same workpiece, sequential scanning with a single spot will prolong the processing cycle, and the area processed first may be affected by the heat generated by subsequent scans. Although multiple lasers or multiple laser heads can be used for simultaneous processing, this will significantly increase cost, size, and the difficulty of optical path synchronization control. When using a semi-transparent and semi-reflective beam splitter, the beam splitting ratio is usually limited by the film system parameters, and there are absorption heat generation and reliability issues under high-power conditions.

[0004] Furthermore, existing integrating mirrors are typically used to superimpose multiple sub-beams onto the same target area to improve the energy uniformity of a single beam. The directional relationship of their reflection regions is essentially fixed after manufacturing, making it difficult to simultaneously achieve multi-beam formation, beam spacing adjustment, and energy distribution between beams on the same reflective component. Therefore, it is necessary to provide a compact multi-beam laser quenching head that can adapt to different numbers, locations, and energy requirements. Summary of the Invention

[0005] To better address the situation where multiple adjacent areas to be quenched exist on the same workpiece, this application provides a multi-spot laser quenching head and its control method.

[0006] In a first aspect, the present invention provides a multi-spot laser quenching head, which adopts the following technical solution: A multi-spot laser quenching head includes a laser input component, a beam distribution component, and an adjustment component. The laser input component is used to introduce incident laser light. The beam distribution component includes multiple beam deflection units located within the coverage area of ​​the same incident laser. The adjustment component is connected to each of the beam deflection units to adjust the emission direction of each beam deflection unit. The multiple beam deflection units are divided into one or more deflection groups according to their emission directions. Each deflection group guides its corresponding sub-beam to the same target focusing area. The target focusing areas of different deflection groups are separated from each other to form one or more quenching spots on the workpiece surface.

[0007] Preferably, the beam deflection unit is a reflection unit or a refraction unit, and the deflection group is a reflection group or a refraction group.

[0008] Preferably, the affiliation between each beam deflection unit and each deflection group is adjustable, so as to change the number of beams split by changing the number of deflection groups and / or change the beam splitting ratio by changing the number of beam deflection units contained in each deflection group, and the ratio of the number of beam deflection units among each deflection group is matched with the energy distribution ratio of each light spot.

[0009] Preferably, each beam deflection unit in the same deflection group has an intra-group deflection angle corresponding to its array position, and different deflection groups have different overall deflection angles. The target deflection angle of each beam deflection unit is determined according to the overall deflection angle of its deflection group and the corresponding intra-group deflection angle.

[0010] Preferably, a focusing element is further provided between the beam distribution component and the target focusing area. The number of focusing elements is equal to the number of deflection groups. The sub-beams of each beam deflection unit in the same deflection group are superimposed on the corresponding target focusing area through the same focusing element.

[0011] Preferably, the adjustment assembly includes an electric deflection mechanism connected to each of the beam deflection units, and the electric deflection mechanism includes at least one of a piezoelectric driver, a voice coil driver, a micro servo driver, or a microelectromechanical system driver.

[0012] Preferably, it further includes a control unit and a detection component that detects the state of multiple quenching zones respectively. The control unit determines the target grouping and target deflection angle of each beam deflection unit according to the target spot position and target energy distribution, and adjusts the actual grouping and / or actual deflection angle of the beam deflection unit according to the detection results of the detection component.

[0013] Preferably, the beam deflection unit is a reflection unit, the beam deflection unit is made of oxygen-free copper substrate, the reflective surface of the beam deflection unit is plated with a gold reflective film, and the back or interior of the beam deflection unit is provided with an integrated water-cooling channel.

[0014] Preferably, it also includes multiple protective gas nozzles, each of which is aligned with a multiple target focusing area, and the gas source for the protective gas nozzles is a nitrogen gas source or an argon gas source.

[0015] Secondly, this invention provides a control method for a multi-spot laser quenching head, employing the following technical solution: A method for controlling a multi-spot laser quenching head includes the following steps: S1: Obtain the location parameters and energy requirements of the target quenching area; S2: Determine the number of deflection groups and the number of beam deflection units contained in each deflection group based on the number of target quenching areas and energy requirements. S3: Determine the overall deflection angle of each deflection group and the intra-group deflection angle of each beam deflection unit based on the position parameters of each target quenching area. S4: Control each of the beam deflection units to deflect according to the corresponding deflection angle, so that the sub-beams corresponding to the same deflection group are guided to the same target quenching area, and the sub-beams corresponding to different deflection groups are guided to different target quenching areas, so as to form multiple quenching spots on the workpiece surface. S5: Move the multiple quenching spots relative to the workpiece to perform synchronous laser quenching on the multiple target quenching areas.

[0016] The beneficial effects of this invention are as follows: 1. By spatially distributing the same incident laser through multiple adjustable beam deflection units and dividing the beam deflection units into one or more deflection groups, different deflection groups can form quenching spots that are separate from each other. Multiple target areas can be processed simultaneously using one laser and one quenching head, reducing the number of equipment and processing time, and lowering equipment costs and the difficulty of optical path synchronization control. 2. The present invention can adjust the affiliation relationship between each beam deflection unit and the deflection group, adjust the number of quenching spots by changing the number of deflection groups, and adjust the energy distribution ratio between the spots by changing the number of beam deflection units contained in each deflection group. Therefore, it can adapt to quenching areas with different numbers, positions and energy requirements, and improve the processing adaptability of the equipment. 3. The present invention determines the position of the corresponding quenching spot based on the overall deflection angle of each deflection group, and corrects the landing point of the sub-beam by using the deflection angle within the group corresponding to each beam deflection unit. This can adjust the spacing between adjacent quenching spots, as well as the size, outline and internal energy distribution of a single spot, which is beneficial to improving the spot forming accuracy and quenching quality. 4. The present invention determines the grouping and deflection angle of each beam deflection unit by the control unit according to the target spot position and target energy distribution, and performs feedback adjustment in combination with the quenching area status obtained by the detection component. This can correct the deviation of the spot position and actual energy distribution in a timely manner, so that multiple target quenching areas are kept within the corresponding process range, thereby improving the stability and consistency of the quenching process. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the laser path in an embodiment of this application; Figure 2 This is a control module diagram of the deflection group in an embodiment of this application; Figure 3This is a top view of the beam distribution component in an embodiment of this application; Figure 4 This is a laser incident pattern of the reflection unit and the refraction unit in the embodiments of this application; Figure 5 This is a laser emission diagram of the beam deflection unit in the embodiments of this application; Figure 6 This is a longitudinal sectional view of the reflective unit in an embodiment of this application; Figure 7 This is a cross-sectional view of the reflective unit in an embodiment of this application; Figure 8 This is a flowchart illustrating the control method in an embodiment of this application.

[0018] Explanation of reference numerals in the attached drawings: 1. Electric deflection mechanism; 2. Beam deflection unit; 21. Reflection unit; 211. Gold reflective film; 212. Integrated water-cooled flow channel; 22. Refraction unit; 3. Focusing element; 4. Quenching spot; 5. Workpiece; 6. Protective gas nozzle. Detailed Implementation

[0019] The following will combine Figures 1-8 The present invention will be further illustrated by the embodiments.

[0020] Example 1:

[0021] This embodiment discloses a multi-spot laser quenching head and its control method.

[0022] Reference Figures 1 to 7 The multi-spot laser quenching head includes a laser input component, a beam distribution component, and an adjustment component. The laser input component and the beam distribution component are mounted inside the quenching head housing along the beam propagation direction. An installation reference is provided within the housing to define the relative positions of each optical element, thereby reducing the impact of assembly errors on the subsequent spot position. The laser input component is used to introduce the incident laser. In this embodiment, the laser input component includes a laser head input end connected to the laser, a beam expander, and a collimator. The laser output from the laser, after beam expansion and collimation, forms parallel or approximately parallel light covering the effective reflection area of ​​the beam distribution component.

[0023] The beam distribution assembly includes multiple beam deflection units 2 located within the coverage area of ​​the same incident laser. These beam deflection units 2 are arranged in an array of narrow strips along a straight line. Their outlines can be rectangular, trapezoidal, parallelogram, sector-shaped, or other shapes that can be joined adjacently. Each beam deflection unit 2 receives a portion of the incident laser and forms a corresponding sub-beam, with sufficient clearance between each beam deflection unit 2 for independent deflection. An adjustment assembly is connected to each beam deflection unit 2. The adjustment assembly enables each beam deflection unit 2 to deflect independently around a deflection axis, adjusting the emission direction of each beam deflection unit 2, thereby changing the propagation direction of the corresponding sub-beam.

[0024] In this embodiment, the beam deflection unit 2 is preferably a reflection unit 21. The reflection unit 21 can reduce the absorption loss of the beam, thereby making the light energy utilization rate higher.

[0025] Multiple reflecting units 21 are divided into one or more reflecting groups according to the reflection direction. Each reflecting group guides the corresponding sub-beam to the same target focusing area. The target focusing areas of different reflecting groups are separated from each other to form one or more quenching spots 4 on the surface of the workpiece 5. When all reflecting units 21 are grouped into the same reflecting group, the quenching head forms one quenching spot 4 and operates in a single-spot state. When the reflecting units 21 are divided into two, three or more reflecting groups, two, three or more separate quenching spots 4 are formed respectively and the quenching head operates in a multi-spot state. Therefore, the number of reflecting groups is not limited to two groups, and its maximum number can be determined according to the number of reflecting units 21 and the number of processing areas. Finally, by spatially dividing and directionally combining the same incident laser by multiple independent reflecting units 21, multiple areas can be processed simultaneously using one laser and one quenching head, reducing the repetitive thermal effects caused by sequential processing and eliminating the need for power synchronization mechanisms between multiple lasers and multiple complete quenching heads.

[0026] It should be noted that the area of ​​each reflecting unit 21 can be the same, or it can be set differently according to the cross-sectional shape of the incident laser and the local power density. In addition, the reflecting units 21 in the same reflecting group can be continuously adjacent in the array, or they can be distributed at intervals, as long as their corresponding sub-beams are guided to the same target focusing area.

[0027] The correspondence between each reflective unit 21 and each reflective group is not fixed; that is, the affiliation between each reflective unit 21 and each reflective group is adjustable. This allows for changing the number of beam splitters by changing the number of reflective groups and / or changing the beam splitting ratio by changing the number of reflective units 21 contained in each reflective group. Furthermore, the ratio of the number of reflective units 21 between each reflective group matches the energy distribution ratio of each light spot. Specifically, the control unit pre-establishes a mapping relationship between the reflective unit 21 number, array position, effective reflective area, incident power density, reflection efficiency, and its current reflective group. Based on the target light spot number and target energy distribution ratio, it redetermines the grouping of each reflective unit 21. Grouping adjustment is preferably completed when the laser is off or in a safe power state. The processing laser is output only after each reflective unit 21 reaches the target deflection position and its status is confirmed, to avoid the sub-beam deviating from the predetermined processing area during grouping switching. If the area, reflection efficiency, and received incident power density of each reflective unit 21 are approximately the same, the ratio of the number of reflective units 21 contained in each reflective group can approximately characterize the energy distribution ratio of each quenching light spot 4. For example, when using thirty-six approximately equal-area reflective units 21, they can be divided into two groups of 18:18 to obtain an approximately 1:1 energy distribution; or they can be divided into two groups of 28:8 to ensure that the first quenching spot 4 receives higher energy than the second quenching spot 4. When the area of ​​the reflective units 21 or the incident power they receive are different, the control unit groups them according to the effective reflection power weight of each reflective unit 21, so that the ratio of the effective reflection power of each reflective group matches the target energy distribution ratio, rather than simply determining the beam splitting ratio based on the number of reflective units 21.

[0028] Each reflector group has an overall deflection angle corresponding to its target focusing area. Different reflector groups have different overall deflection angles to adjust the position of each quenching spot 4 and the distance between adjacent quenching spots 4. By simultaneously increasing the difference in the overall deflection angles of two adjacent reflector groups, the center distance between the corresponding two quenching spots 4 can be increased. By decreasing the difference in the overall deflection angles, the center distance between the corresponding two quenching spots 4 can be decreased. Each reflector unit 21 in the same reflector group has an intra-group deflection angle corresponding to its array position. The target deflection angle of each reflector unit 21 is determined by the overall deflection angle of its reflector group and its own intra-group deflection angle, so that the sub-beams corresponding to the same reflector group are superimposed in the same target focusing area or distributed in a predetermined manner. During assembly and adjustment, a low-power indicator light or detection light can be used to calibrate each reflector unit 21 one by one to obtain the correspondence between the reflector unit 21 number, the driving command and the sub-beam landing point, and the calibration result is stored as deflection control parameters. When a high energy density light spot is required, the sub-beams of the same reflector group can essentially overlap within the target focusing area. When it is required to increase the light spot area or improve energy uniformity, the compensation deflection amount of some reflector units 21 can be finely adjusted so that the sub-beams of the same group are distributed in the target focusing area according to a predetermined position. Thus, the position of the light spot and the spacing between adjacent light spots can be adjusted by using the overall deflection angle, and the size, outline and internal energy distribution of a single light spot can be adjusted by using differentiated intra-group deflection amounts.

[0029] A focusing element 3 is also provided between the beam distribution component and the target focusing area. The number of focusing elements 3 is equal to the number of reflection groups. Each focusing element 3 is installed on the reflection light path of the corresponding reflection group and has an effective light transmission aperture that allows all sub-beams of the reflection group to pass through. The focusing element 3 can be a focusing lens, a focusing lens group, or a reflective focusing element 3. Its focal length can be set to be the same to form multiple quenching spots 4 with approximately the same size. Alternatively, it can be set differently according to the energy density or spot size requirements of different target focusing areas. The position and aperture of the focusing element 3 are determined according to the maximum allowable deflection range of the corresponding reflective group to avoid light blocking or beam interruption during the adjustment of the spot spacing. Finally, the focusing element 3 receives the sub-beams reflected by each reflective unit 21 in the corresponding reflective group and converges or superimposes the sub-beams of the same group onto the corresponding target focusing area to form quenching spots 4 that meet the quenching requirements. Furthermore, by selecting the focal length, aperture, and installation position of the focusing element 3, the size, shape, energy density, and working distance of the quenching spot 4 can be further adjusted to ensure that the spots formed by different reflective groups act accurately on the corresponding quenching areas.

[0030] The adjustment assembly includes an electrically driven deflecting mechanism 1 connected to each reflecting unit 21. The electrically driven deflecting mechanism 1 includes at least one of a piezoelectric driver, a voice coil driver, a micro servo driver, or a microelectromechanical system (MEMS) driver. A connecting seat is provided between each electrically driven deflecting mechanism 1 and its corresponding reflecting unit 21. The connecting seat is used to convert the linear or rotational displacement of the driver into the deflection motion of the reflecting unit 21. The electrically driven deflecting mechanism 1 can drive the reflecting unit 21 to rotate around a single deflection axis. Specifically, the piezoelectric driver is suitable for short-stroke, high-resolution deflection; the voice coil driver is suitable for rapid continuous adjustment; the micro servo driver is suitable for a large angle range adjustment; and the MEMS driver is suitable for high-density integration of the reflecting unit 21. Furthermore, the electrically driven deflecting mechanism 1 can be configured with a position sensor or perform open-loop control based on the calibration relationship between the driving voltage, driving current, and deflection angle. In this embodiment, a closed-loop driving method with position feedback is preferred. Additionally, the driving range of each electrically driven deflecting mechanism 1 should cover the deflection angle range corresponding to single spot, multiple spots, and the maximum spot spacing. Its angle adjustment accuracy can be determined based on the working distance and the allowable spot position error.

[0031] The system also includes a control unit and detection components that detect the state of multiple quenched areas. The control unit determines the target grouping and target deflection angle of each reflective unit 21 based on the target spot position and target energy distribution, and adjusts the actual grouping and / or actual deflection angle of the reflective units 21 based on the detection results of the detection components. The control unit can be an industrial computer, industrial controller, motion controller, or a combination thereof, and is communicatively connected to each electric deflection mechanism 1, laser, and detection component. Before processing, the control unit acquires at least one of the following: the number and position of the target quenched areas, target temperature, target hardened layer depth, target spot size, and target energy distribution. Based on this, it determines the number of reflective groups, the reflective units 21 contained in each reflective group, and the target deflection angle of each reflective unit 21. The detection components may include at least one of an infrared thermometer, a thermal imager, a power detector, and a spot position detector. Each detector can be aligned with its corresponding target quenched area, or multiple target quenched areas can be detected through field coverage or scanning. During the quenching process, the control unit compares the measured temperature, effective power, or spot position of each target quenching area with the corresponding target value. When the measured energy of a target quenching area is lower than the target range, the effective reflection unit 21 of that reflection group can be increased, the deflection angle of some reflection units 21 can be adjusted to increase the effective energy falling into that area, or at least one of the laser power, scanning speed, and defocusing amount can be adjusted. When the measured energy is higher than the target range, the adjustment in the opposite direction is performed. In addition, each adjustment is limited to a preset safety range to avoid sudden changes in spot position or energy.

[0032] The reflective unit 21 is made of oxygen-free copper substrate. A gold reflective film 211 is deposited on the reflective surface of the reflective unit 21, and an integrated water-cooling channel 212 is provided on the back or inside of the reflective unit 21. The oxygen-free copper substrate has high thermal conductivity, enabling rapid transfer of heat absorbed by the reflective surface to the water-cooling channel. The film parameters of the gold reflective film 211 are determined according to the incident laser wavelength and incident angle range. A transition film layer can also be provided between the gold reflective film 211 and the oxygen-free copper substrate to improve adhesion and block the diffusion of substrate elements. The reflective surface is processed to meet the surface roughness and flatness requirements of laser reflection to reduce scattering loss and reflected wavefront distortion.

[0033] It is important to note that the water-cooled flow channels are positioned to avoid the deflection fulcrum of the reflector unit 21 and the electric deflection mechanism 1, and are connected to the external circulating cooling device through the inlet and return water collection channels. For the flow channel interfaces that move with the reflector unit 21, flexible pipes or sealed joints capable of accommodating small-angle deflections can be used. The circulating cooling device allows coolant to flow sequentially through each water-cooled flow channel, carrying away the heat generated by the reflector unit 21. The water-cooling circuit can be equipped with flow sensors, pressure sensors, and temperature sensors. When the coolant flow rate is below a threshold, the pressure is abnormal, or the return water temperature is above a threshold, the control unit reduces the laser power or stops the laser output to prevent damage to the reflector film and the electric deflection mechanism 1 due to overheating.

[0034] It also includes multiple protective gas nozzles 6, each aimed at a different target focusing area. The protective gas nozzles 6 are supplied with either nitrogen or argon. The number of protective gas nozzles 6 is the same as the number of target focusing areas. Each protective gas nozzle 6 is connected to the main gas supply pipe via an independent branch. A flow regulating valve or solenoid valve is installed on each independent branch to adjust the protective gas flow rate for each target focusing area. The protective gas nozzles 6 are angled relative to the surface of the workpiece 5, with their spray direction directed towards the corresponding quenching spot 4, avoiding the processing light path incident on the surface of the workpiece 5. The distance between the nozzle outlet and the surface of the workpiece 5, as well as the spray angle, are determined based on the spot size, scanning direction, and the surface shape of the workpiece 5. Based on this, the control unit opens the corresponding protective gas branch before laser output, creating a stable protective gas flow in the target focusing area, and closes the protective gas after a delay after the laser stops. Nitrogen or argon can reduce the contact between the high-temperature quenching area and air, reducing oxidation and ablation on the surface of the workpiece 5, while also blowing away fumes and spatter generated during the quenching process, reducing the possibility of contamination of the focusing element 3. The gas supply branch can also be equipped with a gas pressure or flow detector. When the protective gas pressure or flow is lower than the set value, the control unit will issue an alarm and limit the laser output.

[0035] Reference Figure 8 The control method for a multi-spot laser quenching head includes the following steps: S1: Obtain the position parameters and energy requirements of the target quenching area. The position parameters include the number of target quenching areas, their center position, boundary contour, distance between adjacent target quenching areas, and their coordinates in the workpiece 5 coordinate system. These position parameters can be obtained by manually inputting machining parameters, calling a pre-stored workpiece 5 machining program, or by a vision inspection device or a position detection device. The energy requirements of the target quenching area include at least one of the following: target temperature, target energy density, target spot size, target hardened layer depth, and target surface hardness. The control unit converts the energy requirements of each target quenching area into a corresponding target energy allocation ratio based on parameters such as the workpiece 5 material, target hardened layer depth, laser power, and scanning speed. For example, when two target quenching areas have the same quenching requirements, their target energy allocation ratio can be determined to be 1:1; when the target hardened layer depth or target surface hardness of the two target quenching areas are different, different target energy allocation ratios are determined for the two target quenching areas.

[0036] S2: Based on the number of target quenching areas and energy requirements, determine the number of reflection groups and the number of reflection units 21 contained in each reflection group. The control unit sets the number of reflection groups to correspond to the number of target quenching areas, so that each reflection group corresponds to one target quenching area. When only one quenching spot 4 needs to be formed, all reflection units 21 can be assigned to the same reflection group; when two, three or more quenching spots 4 need to be formed, multiple reflection units 21 are assigned to two, three or more reflection groups respectively. The control unit determines the reflection units 21 contained in each reflection group according to the target energy distribution ratio of each target quenching area. When the effective reflection area, reflection efficiency and received incident power of each reflection unit 21 are approximately the same, the ratio of the number of reflection units 21 contained in each reflection group matches the target energy distribution ratio of the corresponding quenching spot 4. When the effective reflective area or the incident power received by each reflective unit 21 is different, the control unit determines the corresponding effective reflective power weight based on the effective reflective area, local incident power density, reflection efficiency, and optical path loss of each reflective unit 21, and matches the sum of the effective reflective power weights of the reflective units 21 included in each reflective group with the target energy distribution ratio. This avoids deviations in actual energy distribution caused by grouping solely according to the number of reflective units 21.

[0037] S3: Based on the position parameters of each target quenching area, determine the overall deflection angle of each reflection group and the intra-group deflection angle of each reflection unit 21. The control unit determines the overall deflection angle of each reflection group according to the law of reflection, based on the relative positions between the beam distribution component, the focusing element 3, and the workpiece 5, the focal length of the focusing element 3, and the center position of the target quenching area. The overall deflection angle is used to determine the center position of the quenching spot 4 formed by the corresponding reflection group. Different reflection groups have different overall deflection angles. By changing the difference in the overall deflection angles between different reflection groups, the distance between adjacent quenching spots 4 can be adjusted. Since the positions of each reflection unit 21 in the same reflection group are different in the array, even if their corresponding sub-beams need to be guided to the same target quenching area, the actual deflection amount required by each reflection unit 21 is not exactly the same. Therefore, the control unit further determines the intra-group deflection angle of each reflection unit 21 based on the array position of each reflection unit 21, its optical path to the corresponding focusing element 3, and the position of the target focusing area. The target deflection angle of each reflection unit 21 is determined by the overall deflection angle of its reflection group and the intra-group deflection angle of that reflection unit 21, that is: The target deflection angle of the reflection unit 21 = the overall deflection angle of the reflection group + the corresponding intra-group deflection angle; The control unit can also call pre-calibrated deflection control parameters. During calibration, a low-power indicator light is used to deflect each reflector unit 21 sequentially, and the actual landing point of the corresponding sub-beam on the target plane is detected, thereby establishing the correspondence between the drive command, the deflection angle of the reflector unit 21, and the landing point of the sub-beam. By correcting the theoretically calculated deflection angle through the calibration results, the installation error of the reflector unit 21, the drive error, and the assembly error of the optical components can be compensated.

[0038] S4: Control each reflecting unit 21 to deflect according to the corresponding deflection angle, so that the sub-beams corresponding to the same reflecting group are guided to the same target quenching area, and the sub-beams corresponding to different reflecting groups are guided to different target quenching areas, so as to form multiple quenching spots 4 on the surface of the workpiece 5. When the laser is off or in a safe power state, the control unit sends drive commands to each electric deflection mechanism 1 to make each reflecting unit 21 reach the corresponding target deflection angle. When each reflecting unit 21 is equipped with a position feedback mechanism, the control unit compares the actual deflection angle with the target deflection angle; when the deviation is within the preset allowable range, it is determined that the reflecting unit 21 has reached the position. When no position feedback mechanism is set, the position can be determined according to the calibration relationship between the driving voltage, driving current or driving pulse and the deflection angle. After each reflecting unit 21 has reached the position, the control unit controls the laser to output the processing laser. The multiple sub-beams corresponding to the same reflecting group are converged to the corresponding target quenching area by the same focusing element 3, and are superimposed in the target quenching area to form quenching spots 4. Sub-beams corresponding to different reflection groups are guided to different target quenching regions by corresponding focusing elements 3, thereby forming multiple quenching spots 4 separated from each other on the surface of the workpiece 5. When it is necessary to increase the energy density of the quenching spot 4, the sub-beams in the same reflection group can be made to basically overlap in the target quenching region; when it is necessary to expand the spot size or improve the energy uniformity inside the spot, the deflection angle within some reflection units 21 can be finely adjusted so that the sub-beams in the same group are distributed in the target quenching region according to the predetermined position.

[0039] S5: Multiple quenching spots 4 are moved relative to the workpiece 5 to simultaneously perform laser quenching on multiple target quenching areas. Specifically, the multi-spot laser quenching head can be kept fixed while driving the workpiece 5, or the workpiece 5 can be kept fixed while driving the multi-spot laser quenching head, or both can move simultaneously. The control unit determines the relative motion trajectory and scanning speed based on the extension direction of the target quenching area, the depth of the target hardened layer, and the target temperature, so that multiple quenching spots 4 scan synchronously along the corresponding target quenching areas. During the simultaneous laser quenching process, the detection component detects the actual temperature, spot position, or effective power of each target quenching area. The control unit compares the detection results with the corresponding target values ​​and adjusts the laser power, scanning speed, actual grouping of the reflection units 21, the overall deflection angle of the reflection group, and / or the intra-group deflection angle of the reflection units 21 according to the comparison results. When the actual temperature of a target quenching area is lower than the target range, the number of effective reflection units 21 of the corresponding reflection group can be increased or the effective energy falling into the area can be increased; when the actual temperature is higher than the target range, the effective reflection energy of the corresponding reflection group can be reduced or the scanning speed can be increased, so that multiple target quenching areas are kept within the corresponding quenching process range.

[0040] As a specific operating mode, the beam distribution assembly includes 36 approximately equal-area reflective units 21. When two target quenching regions have the same energy requirement, the 36 reflective units 21 can be divided into two reflective groups at a ratio of 18:18; when the two target quenching regions have different energy requirements, they can be grouped at a ratio of 28:8 or other proportions. The control unit adjusts the center distance between the two quenching spots 4 to 30mm, 65mm, or other distances corresponding to the two target quenching regions on the workpiece 5 by changing the overall deflection angle of the two reflective groups, thereby achieving synchronous laser quenching of regions with different positions and different energy requirements.

[0041] Example 2:

[0042] This embodiment also discloses a multi-spot laser quenching head.

[0043] Reference Figure 4 and Figure 5 The difference from Embodiment 1 is that, in this embodiment, the beam deflection unit 2 is preferably a refraction unit 22, and the deflection group is a refraction group. Multiple refraction units 22 are located within the coverage area of ​​the same incident laser, and each refraction unit 22 receives a portion of the incident laser and forms a corresponding sub-beam. The refraction unit 22 can be a transparent prism, a wedge lens, or other optical element capable of changing the propagation direction of the sub-beam through refraction. Its material can be selected according to the laser wavelength, such as quartz glass, optical glass, or other light-transmitting materials resistant to high-power lasers. Anti-reflection coatings can be provided on the incident and exit surfaces to reduce reflection loss.

[0044] Each refractive unit 22 is connected to a corresponding electric deflection mechanism 1. The electric deflection mechanism 1 adjusts the spatial orientation of the refractive unit 22 to change the incident angle of the incident laser at the refractive interface, thereby adjusting the exit direction of the corresponding sub-beam. Multiple refractive units 22 are divided into one or more refractive groups according to the exit direction. Each refractive unit 22 in the same refractive group guides the corresponding sub-beam to the same target focusing area, while different refractive groups guide the sub-beams to separate target focusing areas, thereby forming one or more quenching spots 4 on the surface of the workpiece 5.

[0045] The affiliation between each refractive unit 22 and the refractive group can be adjusted according to the number of target quenching areas and energy requirements. The number of quenching spots 4 can be adjusted by changing the number of refractive groups, and the energy distribution ratio between different quenching spots 4 can be adjusted by changing the number of refractive units 22 contained in each refractive group or the effective transmission power. Each refractive group has an overall deflection angle that matches the corresponding target focusing area, and each refractive unit 22 in the same refractive group has an intra-group deflection angle corresponding to its array position, so that the sub-beams in the same group are accurately guided to the corresponding target focusing area.

[0046] In this embodiment, the control unit determines the target deflection angle of each refractive unit 22 based on the refractive index, incident angle, installation position, parameters of the focusing element 3, and the position of the target focusing area. It can also correct the target deflection angle by combining a pre-calibrated correspondence between the driving command and the sub-beam landing point. The sub-beams corresponding to each refractive group are converged or superimposed by the corresponding focusing element 3, forming multiple quenching spots 4 on the surface of the workpiece 5 that meet the quenching requirements. Except for the different beam deflection methods described above, other structures, control methods, and working processes in this embodiment can refer to Embodiment 1, and will not be repeated here.

[0047] The above are all preferred embodiments of the present invention and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A multi-spot laser quenching head, characterized in that: The system includes a laser input component, a beam distribution component, and an adjustment component. The laser input component is used to introduce incident laser light. The beam distribution component includes multiple beam deflection units (2) located within the coverage area of ​​the same incident laser light. The adjustment component is connected to each of the beam deflection units (2) to adjust the emission direction of each of the beam deflection units (2). The multiple beam deflection units (2) are divided into one or more deflection groups according to the emission direction. Each deflection group guides the corresponding sub-beam to the same target focusing area. The target focusing areas of different deflection groups are separated from each other to form one or more quenching spots (4) on the surface of the workpiece (5).

2. The multi-spot laser quenching head according to claim 1, characterized in that: The beam deflection unit (2) is a reflection unit (21) or a refraction unit (22), and the deflection group is a reflection group or a refraction group.

3. The multi-spot laser quenching head according to claim 1, characterized in that: The affiliation between each beam deflection unit (2) and each deflection group is adjustable to change the number of beams split by changing the number of deflection groups and / or to change the beam splitting ratio by changing the number of beam deflection units (2) contained in each deflection group, and the ratio of the number of beam deflection units (2) between each deflection group is matched with the energy distribution ratio of each quenching spot.

4. The multi-spot laser quenching head according to claim 3, characterized in that: Each beam deflection unit (2) in the same deflection group has an intra-group deflection angle corresponding to its array position. Different deflection groups have different overall deflection angles. The target deflection angle of each beam deflection unit (2) is determined according to the overall deflection angle of its deflection group and the corresponding intra-group deflection angle.

5. A multi-spot laser quenching head according to claim 1, characterized in that: A focusing element (3) is also provided between the beam distribution component and the target focusing area. The number of focusing elements (3) is equal to the number of deflection groups. The sub-beams of each beam deflection unit (2) in the same deflection group are superimposed on the corresponding target focusing area through the same focusing element (3).

6. A multi-spot laser quenching head according to claim 1, characterized in that: The adjustment assembly includes an electric deflection mechanism (1) connected to each of the beam deflection units (2), and the electric deflection mechanism (1) includes at least one of a piezoelectric driver, a voice coil driver, a micro servo driver, or a microelectromechanical system driver.

7. A multi-spot laser quenching head according to claim 4, characterized in that: It also includes a control unit and a detection component that detects the state of multiple quenching zones respectively. The control unit determines the target grouping and target deflection angle of each beam deflection unit (2) according to the target spot position and target energy distribution, and adjusts the actual grouping and / or actual deflection angle of the beam deflection unit (2) according to the detection results of the detection component.

8. A multi-spot laser quenching head according to claim 1, characterized in that: The beam deflection unit (2) is a reflection unit (21). The beam deflection unit (2) is made of oxygen-free copper substrate. The reflective surface of the beam deflection unit (2) is coated with a gold reflective film (211). An integrated water-cooling channel (212) is provided on the back or inside of the beam deflection unit (2).

9. A multi-spot laser quenching head according to claim 1, characterized in that: It also includes multiple protective gas nozzles (6), which are respectively aligned with multiple target focusing areas. The gas source of the protective gas nozzles (6) is a nitrogen gas source or an argon gas source.

10. A control method for a multi-spot laser quenching head as described in any one of claims 1 to 9, characterized in that, Includes the following steps: S1: Obtain the location parameters and energy requirements of the target quenching area; S2: Determine the number of deflection groups and the number of beam deflection units (2) contained in each deflection group according to the number of target quenching areas and energy requirements. S3: Determine the overall deflection angle of each deflection group and the intra-group deflection angle of each beam deflection unit (2) based on the position parameters of each target quenching area; S4: Control each of the beam deflection units (2) to deflect according to the corresponding deflection angle, so that the sub-beams corresponding to the same deflection group are guided to the same target quenching area, and the sub-beams corresponding to different deflection groups are guided to different target quenching areas, so as to form multiple quenching spots (4) on the surface of the workpiece (5). S5: Move the multiple quenching spots (4) relative to the workpiece (5) to perform synchronous laser quenching on the multiple target quenching areas.

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