Laser-assisted adaptive ultrasonic micro-rolling working head and processing method

Abstract

The application discloses a laser-assisted self-adaptive ultrasonic micro-rolling working head and a processing method, wherein the protective lens, the collimating mirror, the focusing mirror, the hollow annular voice coil motor, the hollow piezoelectric ceramic stack and the hollow multi-section cascade amplitude transformer are arranged around the same central channel; the axial force generated by the hollow annular voice coil motor is transmitted to the array ball of the hollow multi-section cascade amplitude transformer and the hollow multi-ball array rolling head through the coarse buffer spring, the coarse spring lower base, the first end pressing part, the hollow piezoelectric ceramic stack in the compressed pre-tightening state and the second end pressing part in sequence; during processing, the working head is connected with external matched equipment and continuously fed, so that the laser irradiation area formed by the central channel firstly passes through the workpiece surface, and then the array ball located at the rear side of the feeding direction implements ultrasonic micro-rolling in the heat-affected tail trace, and the coarse buffer spring and the plane flexible leaf spring adapt to the surface relief through elastic deformation.

Description

Technical Field

[0001] This invention relates to the fields of mechanical manufacturing and additive manufacturing post-processing technology, specifically to a laser-assisted adaptive ultrasonic micro-rolling head and processing method suitable for continuous finishing of the inner surface of deep holes. Background Technology

[0002] The inner surfaces of deep holes in additively manufactured parts and other complex components may exhibit stepped effects, wavy lines, and local undulations. When using a rolling tool to finish such inner surfaces, if the working head has a rigid loading structure, the rolling head is prone to sudden changes in contact load when passing through local protrusions or depressions, affecting the consistency of the rolling state.

[0003] Laser preheating can reduce the instantaneous deformation resistance of the workpiece surface material, and ultrasonic vibration can improve the rolling effect. However, within the limited radial space of deep holes, setting up laser processing heads, rolling processing heads, and gas protection structures separately will increase the intrusion size into the hole and make it difficult to maintain a fixed relationship between the laser preheating area and the subsequent rolling position. Existing solutions also lack a clear technical relationship to unify the static rolling pressure, mechanical compliance, and the time interval between laser preheating and rolling into the same processing flow.

[0004] Therefore, a working head that integrates optical path, air path, static pressure transmission path and ultrasonic vibration transmission path around the same central channel is needed, along with a parameter determination method and a continuous processing method corresponding to the structure of the working head. Summary of the Invention

[0005] In order to solve the technical problems existing in the prior art, the purpose of this invention is to provide a laser-assisted adaptive ultrasonic micro-rolling head and processing method, so as to establish a fixed relative relationship between laser preheating and ultrasonic rolling in a confined deep hole space, and reduce the sudden change of rolling load caused by workpiece surface undulation through a mechanically compliant structure.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides a laser-assisted adaptive ultrasonic micro-rolling head, comprising a housing 18, a protective lens 4, a collimating lens 2, a focusing lens 3, a first air inlet branch 19-1, a second air inlet branch 19-2, a hollow annular voice coil motor 5, a coarse spring upper base 16, a coarse buffer spring 14, a coarse spring lower base 17, a first end clamping component 15-1, a hollow piezoelectric ceramic stack 15, a hollow pre-tightening bolt 15-2, a second end clamping component 15-3, a leaf spring flange 13, a planar flexible leaf spring 6, a flange 20, a hollow multi-section cascaded amplitude transformer 7, and a hollow multi-ball array rolling head; the collimating lens 2, the focusing lens 3, and the protective lens 4 are sequentially located on the central optical axis, and the hollow piezoelectric ceramic stack 15, the first end clamping component 15-1, the hollow pre-tightening bolt 15-2, the second end clamping component 15-3, the hollow multi-section cascaded amplitude transformer 7, and the hollow multi-ball array rolling head are aligned along the same central axis. A central axis is set to form a central channel penetrating the working head; the first air intake branch 19-1 is connected to the central channel, and the second air intake branch 19-2 is connected to the annular cavity formed between the hollow annular voice coil motor 5 and the outer shell 18; the hollow annular voice coil motor 5 includes a stator and a mover, the stator is rigidly fixed to the outer shell 18, and the mover is rigidly connected to the upper base 16 of the coarse spring, and can move axially relative to the stator and the outer shell 18 along the central axis; the two ends of the coarse buffer spring 14 abut or are fixed to the upper base 16 of the coarse spring and the lower base 17 of the coarse spring, respectively; the axial bearing end of the lower base 17 of the coarse spring abuts against the first end clamping member 15-1, and ... 7 is not fixedly connected to the outer casing 18; the first end clamping member 15-1 is located at the end of the hollow piezoelectric ceramic stack 15 near the lower base 17 of the coarse spring, and the second end clamping member 15-3 is located at the end of the hollow piezoelectric ceramic stack 15 near the hollow multi-section cascaded amplitude transformer 7. The hollow piezoelectric ceramic stack 15 is clamped between the first end clamping member 15-1 and the second end clamping member 15-3; the hollow preload bolt 15-2 is a slender hollow tie rod with limited axial stiffness. One end of the rod is provided with a bolt head that presses against the first end clamping member 15-1, and the other end is threadedly connected to the axial threaded hole of the second end clamping member 15-3; after tightening the hollow preload bolt 15-2, the rod of the hollow preload bolt 15-2 is under axial tension. In the extended state, the hollow piezoelectric ceramic stack 15 is in an axially compressed pre-tightened state; when the hollow piezoelectric ceramic stack 15 elongates or contracts axially under the action of alternating voltage, the rod of the hollow pre-tightening bolt 15-2 undergoes corresponding elastic elongation or retraction, so as to allow axial micro-displacement between the first end clamping member 15-1 and the second end clamping member 15-3, and to keep the hollow piezoelectric ceramic stack 15 in compression contact during operation; the second end clamping member 15-3 is rigidly connected to the input end of the hollow multi-section cascaded amplitude transformer 7, and the output end of the hollow multi-section cascaded amplitude transformer 7 is rigidly connected to the hollow multi-ball array rolling head; the flange 20 is sleeved on the outer periphery of the hollow multi-section cascaded amplitude transformer 7 and fixedly connected to it;The axial force generated by the hollow ring voice coil motor 5 is sequentially transmitted through the upper base 16 of the coarse spring, the coarse buffer spring 14, the lower base 17 of the coarse spring, the first end clamping member 15-1, the hollow piezoelectric ceramic stack 15 in a compressed pre-tightened state, and the second end clamping member 15-3 to the hollow multi-section cascaded amplitude transformer 7 and the hollow multi-ball array rolling head, so as to establish and adjust the rolling static pressure between the hollow multi-ball array rolling head and the workpiece surface; the hollow piezoelectric ceramic stack 15 is electrically connected to the ultrasonic power supply and operates under alternating voltage. Axial periodic expansion and contraction displacement is generated, which is directly transmitted to the hollow multi-section cascaded amplitude transformer 7 and the hollow multi-ball array rolling head via the second end clamping member 15-3. The hollow multi-ball array rolling head has a central through hole communicating with the central channel and includes multiple array balls 8. Along the feed direction of the working head relative to the workpiece, at least one effective rolling contact point of the array balls 8 is located behind the laser irradiation zone, so that the same position on the workpiece surface passes through the laser irradiation zone first and then enters the effective rolling contact point. This coaxial integrated structure avoids the increase in radial dimension caused by separately arranging the laser head, rolling head, and protective gas structure, which is beneficial for the working head to enter the confined deep hole inner surface area.

[0007] To address the challenges of limited processing space in deep hole inner surfaces, difficulty in stably coordinating laser preheating and ultrasonic rolling positions, fluctuations in static rolling pressure caused by local undulations on the workpiece surface, and difficulty in determining the correspondence between laser preheating parameters and rolling positions, this invention integrates the optical path, air path, rolling static pressure transmission path, and ultrasonic vibration transmission path around the same central channel. Furthermore, it establishes a loading structure with axial compliance and radial constraint capabilities using a voice coil motor, a coarse buffer spring, and a planar flexible leaf spring. Simultaneously, it utilizes the fixed geometric relationship between the laser irradiation area and the effective rolling contact point, combined with optical path transmission efficiency, spot width, and thermal response calibration results, to determine processing parameters, thereby achieving continuous coordination between laser preheating and subsequent ultrasonic micro-rolling.

[0008] Preferably, the hollow multi-ball array rolling head includes array balls 8, an annular end face 9 of the rolling head, and an annular retainer 10. The annular end face 9 of the rolling head has multiple ball sockets around the central through hole. Multiple array balls 8 are spaced circumferentially within these ball sockets along the annular end face 9 of the rolling head and are limited by the annular retainer 10. The collimating lens 2 is mounted on the collimating lens mount 11, and the focusing lens 3 is mounted on the focusing lens mount 12. The multiple array balls are spaced circumferentially along the annular end face of the rolling head and limited by the annular retainer 10, allowing each array ball 8 to be distributed around the central through hole. Under the condition that the laser beam and protective gas continue to pass through the central channel, the array balls can still form multiple rolling contact positions with the workpiece surface, which is beneficial for balancing the requirements of central channel penetration and rolling action.

[0009] Preferably, along the central axis, a coarse spring upper base 16 is provided on the side of the hollow annular voice coil motor 5 near the hollow multi-section cascaded amplitude transformer 7. The coarse buffer spring 14 is disposed between the coarse spring upper base 16 and the coarse spring lower base 17. The leaf spring flange 13 is fixed to the outer shell 18. The planar flexible leaf spring 6 has elastic compliance in the axial direction and is constrained in the radial direction. One end of the leaf spring 6 is fixedly connected to the leaf spring flange 13, and the other end is fixedly connected to the flange 20, so as to allow the hollow multi-section cascaded amplitude transformer 7 to generate axial elastic displacement relative to the outer shell 18 and limit its radial offset. The coarse buffer spring 4 is mainly used to provide elastic buffering in the axial loading direction, and the planar flexible leaf spring 6 provides radial guidance and anti-overturning constraint for the hollow multi-section cascaded amplitude transformer 7 while allowing axial elastic displacement. The combination of the two allows the rolling head to generate a slight axial displacement relative to the outer shell when passing over local protrusions or depressions on the surface of the workpiece, thereby reducing sudden changes in contact load; at the same time, it limits the radial offset and overturning of the hollow multi-section cascaded amplitude transformer 7, thus improving the stability of the rolling process.

[0010] Preferably, the coarse spring lower base 17 is a hollow cylindrical base body arranged around the central axis. The end of the coarse spring lower base 17 facing the coarse buffer spring 14 has an axial end face that abuts against the coarse buffer spring 14, and the end facing the first end clamping member 15-1 has an axial end face that abuts against the first end clamping member 15-1 coaxially. A clearance space is left between the coarse spring lower base 17, the leaf spring flange 13, and the planar flexible leaf spring 6 to allow the coarse spring lower base 17 to move relative to the outer shell 18 along the central axis.

[0011] Preferably, the hollow multi-section cascaded amplitude transformer 7 is a continuous hollow rod body integrally formed, which is divided into N continuous acoustic half-wavelength segments along the central axis. The acoustic half-wavelength segments are acoustic segments within the same rod body and are not separate mechanical parts. The interface between adjacent acoustic half-wavelength segments is a longitudinal displacement nodal surface, and the axial distance between adjacent longitudinal displacement nodal surfaces is half of the longitudinal wavelength λ corresponding to the working ultrasonic frequency. The outer contour of the hollow multi-section cascaded amplitude transformer 7 maintains a constant radius along the axial direction. On this basis, the inner hole radius gradually increases from the input end near the second end clamping member 15-3 to the output end near the hollow multi-ball array rolling head, so that the effective annular cross-sectional area of ​​the rod wall at the output end is smaller than that at the input end, thereby forming a reduced cross-section amplitude transformer structure from the input end to the output end, which is beneficial to improving the longitudinal vibration displacement amplitude at the output end of the hollow multi-ball array rolling head. Wherein, N is a positive integer.

[0012] Preferably, it further includes an external connecting base 1 disposed at the end of the outer shell 18 away from the hollow multi-ball array rolling head, for detachable connection with the external posture execution device 25; the external connecting base 1 is provided with an installation structure for connecting with the external posture execution device 25. The external connecting base 1 is disposed at the end of the outer shell away from the hollow multi-ball array rolling head, so that the working head can be detachably connected to the external posture execution device 25. Using the laser 21, voice coil motor drive power supply 22, ultrasonic power supply 23, protective gas source 24 and external posture execution device 25 as external supporting equipment is beneficial to reducing the size of the working head body entering the deep hole area and improving the adaptability of the working head to different processing equipment.

[0013] Preferably, the hollow piezoelectric ceramic stack 15 is composed of multiple hollow annular piezoelectric ceramic units stacked sequentially along the central axis, and the piezoelectric material of each piezoelectric ceramic unit is lead zirconate titanate.

[0014] Secondly, the present invention provides a laser-assisted adaptive ultrasonic micro-rolling processing method, comprising the following steps: S1, the working head is mounted on the external posture execution device 25 via the external connecting base 1. The output beam of the laser 21, which is matched with the working head, is coupled to the central channel of the working head through the collimating lens 2, focusing lens 3, and protective lens 4 to form a laser irradiation area. The voice coil motor drive power supply 22, ultrasonic power supply 23, and protective gas source 24, which are matched with the working head, are respectively connected to the hollow ring voice coil motor 5, the hollow piezoelectric ceramic stack 15, the first air intake branch 19-1, and the second air intake branch 19-2. According to the workpiece material, workpiece surface condition, target rolling static pressure, and processing trajectory, and in conjunction with the pre-calibrated process parameter correspondence, the drive current of the hollow ring voice coil motor 5 and the output power of the laser 21 are set. and the feed rate of the working head Among them, optical path transmission efficiency Pre-calibration is performed by measuring the optical power from the output end of laser 21 to the workpiece surface, and the incident laser power reaching the workpiece surface is then determined. Determined by the following formula: Formula (1) In the formula, The incident laser power reaching the workpiece surface, The optical power at the output of laser 21 To determine the optical path transmission efficiency from the output of laser 21 to the workpiece surface, and ; S2, turn on the protective air source 24, so that the first protective air enters the central channel through the air intake channel 19-1 and is discharged to the processing area through the central through hole of the hollow multi-ball array rolling head; so that the second protective air enters the outer space of the hollow annular voice coil motor 5 through the air intake channel 19-2 and is discharged to the processing area through the annular gap between the outer shell 18 and the hollow multi-section cascaded amplitude transformer 7; the external posture execution device 25 moves the working head to the processing start position; S3, with the hollow pre-tightening bolt 15-2 maintaining the axial compression pre-tightening of the hollow piezoelectric ceramic stack 15, the voice coil motor drive power supply 22 drives the mover of the hollow ring voice coil motor 5, so that the axial force is transmitted sequentially through the upper base 16 of the coarse spring, the coarse buffer spring 14, the lower base 17 of the coarse spring, the first end clamping member 15-1, the hollow piezoelectric ceramic stack 15 and the second end clamping member 15-3 to the hollow multi-section cascaded amplitude transformer 7 and the array ball bearings 8, and a predetermined rolling static pressure is established between the array ball bearings 8 and the workpiece surface; the flange 20, the planar flexible leaf spring 6 and the leaf spring flange 13 provide radial guidance and anti-overturning restraint for the hollow multi-section cascaded amplitude transformer 7; S4, an alternating voltage is applied to the hollow piezoelectric ceramic stack 15 by the ultrasonic power supply 23, causing the hollow piezoelectric ceramic stack 15 to generate periodic expansion and contraction displacement along the central axis, which is transmitted to the hollow multi-section cascaded amplitude transformer 7 and the hollow multi-ball array rolling head through the second end clamping member 15-3; at the same time, the laser 21 is turned on, and the external posture execution device 25 drives the working head to feed continuously, so that the effective rolling contact point of the array balls 8 is located on the rear side of the laser irradiation area along the feed direction, so that the same position on the workpiece surface first passes through the laser irradiation area, and then enters the effective rolling contact point of the array balls 8 for ultrasonic micro-rolling; during the processing, the coarse buffer spring 14 and the planar flexible leaf spring 6 together allow the hollow multi-section cascaded amplitude transformer 7 and the hollow multi-ball array rolling head to generate axial micro-displacement relative to the outer shell 18 to adapt to the local axial undulations of the workpiece surface; the planar flexible leaf spring 6 also restricts the radial offset and overturning of the hollow multi-section cascaded amplitude transformer 7; S5, when the processing is finished, first turn off the laser 21, then stop the processing feed of the working head, and keep the protective gas source 24 on; then turn off the ultrasonic power supply 23, gradually reduce the driving current of the hollow ring voice coil motor 5 to zero, so as to gradually release the rolling static pressure between the array ball 8 and the workpiece surface and stop driving the hollow ring voice coil motor 5; then the external posture execution device 25 drives the working head to detach from the workpiece surface and exit the processing area; after continuing to introduce protective gas for purging, the protective gas source 24 is turned off.

[0015] Compared with the prior art, the present invention has at least the following beneficial effects: 1) The present invention integrates the collimating lens 2, focusing lens 3, protective lens 4, hollow annular voice coil motor 5, hollow piezoelectric ceramic stack 15, hollow multi-section cascaded amplitude transformer 7, and hollow multi-sphere array rolling head around the same central channel, and makes the outer shell 18 stop below the hollow piezoelectric ceramic stack 15. It can integrate beam transmission, protective gas delivery, rolling static pressure transmission and axial ultrasonic vibration transmission functions in the limited radial space of the deep hole, and reduce the radial occupation of the working head entering the deep hole.

[0016] 2) By setting up a first air intake channel 19-1 connected to the central channel and a second air intake channel 19-2 leading to the outside of the hollow annular voice coil motor 5 and exiting through the annular gap between the lower end of the outer shell 18 and the hollow multi-section cascaded amplitude transformer 7, the protective gas can act on the central channel and the inner outer area of ​​the working head respectively, forming a dual-path protective airflow, which is beneficial to improving the gas protection conditions in the deep hole machining area.

[0017] 3) The hollow piezoelectric ceramic stack 15 is coaxially sleeved on the outer periphery of the input section of the hollow multi-section cascaded amplitude transformer 7, and forms an axial positioning and pre-tightening structure through the first end clamping member 15-1, the hollow pre-tightening bolt 15-2 and the second end clamping member 15-3. This allows the hollow piezoelectric ceramic stack 15 to obtain a stable axial pre-tightening and vibration transmission relationship while maintaining the continuity of the central channel, thereby improving the assembly stability and axial vibration transmission stability of the ultrasonic excitation structure.

[0018] 4) The axial force of the hollow ring voice coil motor 5 is transmitted sequentially to the array ball bearings 8 through the coarse buffer spring 14, the coarse spring lower base 17, the flange 20, and the hollow multi-section cascaded amplitude transformer 7. When the array ball bearings 8 pass through the local protrusions or depressions on the workpiece surface, the coarse buffer spring 14 and the planar flexible leaf spring 6 can generate elastic deformation, causing the hollow multi-ball array rolling head to undergo axial displacement relative to the outer shell 18, thereby reducing the sudden change in rolling static pressure caused by surface undulations and improving the consistency of the rolling process.

[0019] 5) Flange 20 is located at the longitudinal displacement node of the hollow multi-section cascaded amplitude transformer 7; the hollow multi-section cascaded amplitude transformer 7 is continuously composed of multiple half-wavelength segments, and its connecting parts and cross-sectional transition parts span the location of the longitudinal displacement node surface. This structure allows the connection, support, and cross-sectional change areas to avoid or approach areas with large longitudinal vibration displacement, reducing the adverse effects of local structures on the transmission of axial ultrasonic vibration, and improving the vibration transmission stability of the hollow multi-section cascaded amplitude transformer 7.

[0020] 6) The present invention utilizes the fixed geometric relationship between the intersection of the central channel optical axis and the workpiece surface and the effective rolling contact point of the array ball 8 located behind the feed direction, so that the laser irradiation area passes through the workpiece surface first, and the array ball 8 then performs ultrasonic micro-rolling in the heat-affected wake, thereby realizing the continuous coordination of laser preheating and subsequent ultrasonic micro-rolling in space and time.

[0021] 7) This invention determines the equivalent laser spot width by pre-calibrating the optical path transmission efficiency from the output end of the laser 21 to the workpiece surface and measuring the two boundary positions of the laser spot along the feed direction on the workpiece surface. Combined with the directional projection distance between the optical axis of the central channel and the effective rolling contact point of the array of balls 8 located behind the feed direction, as well as the target incident laser energy per unit area and the target thermal delay time determined by the pre-determined laser thermal response calibration test, the feed speed of the working head and the output power of the laser 21 are determined. This ensures that when the effective rolling contact point of the array of balls 8 reaches the corresponding position after laser irradiation, the workpiece surface temperature meets the requirement between the thermal softening temperature and the melting temperature, improving the operability and repeatability of the processing parameter determination.

[0022] 8) The laser 21, voice coil motor drive power supply 22, ultrasonic power supply 23, protective gas source 24 and external posture execution device 25 are all set as external equipment to be matched with the working head. The working head can be connected to different external posture execution devices 25 through the external connection base 1, which helps to reduce the size of the working head body and improve its adaptability to be used with different processing equipment. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the overall structure of the working head of the present invention.

[0024] Figure 2 This is a schematic diagram of the connection structure of the hollow piezoelectric ceramic stack, hollow preload bolt, hollow multi-section cascaded amplitude transformer and planar flexible leaf spring of the present invention.

[0025] Figure 3 This is a schematic diagram of the loading, buffering, and guiding structure composed of a hollow annular voice coil motor, a coarse buffer spring, and a planar flexible leaf spring in this invention.

[0026] Figure 4 This is a schematic diagram of a hollow multi-sphere array rolling head.

[0027] Figure 5 This is a schematic diagram of a hollow, multi-section cascaded amplitude transformer.

[0028] Figure 6 This is a schematic diagram showing the connection relationship between the working head of the present invention and external supporting equipment. Detailed Implementation

[0029] The present invention will be further described below with reference to the accompanying drawings and embodiments. The following embodiments are used to illustrate the structure, function, and processing of the working head of the present invention, and are not intended to limit the scope of protection of the present invention.

[0030] like Figure 1 , Figure 2 and Figure 3As shown, the present invention discloses a laser-assisted adaptive ultrasonic micro-rolling head, comprising a housing 18, a protective lens 4, a collimating lens 2, a focusing lens 3, a first air inlet branch 19-1, a second air inlet branch 19-2, a hollow annular voice coil motor 5, a coarse spring upper base 16, a coarse buffer spring 14, a coarse spring lower base 17, a first end clamping component 15-1, a hollow piezoelectric ceramic stack 15, a hollow preload bolt 15-2, a second end clamping component 15-3, a leaf spring flange 13, a planar flexible leaf spring 6, a flange 20, a hollow multi-section cascaded amplitude transformer 7, and a hollow multi-ball array rolling head; the collimating lens 2, the focusing lens 3, and the protective lens 4 are sequentially located on the central optical axis, wherein the collimating lens 2 is used to collimate the laser beam entering the working head, so that the laser beam propagates along the central optical axis in an approximately parallel beam form; the focusing lens 3 is used to focus the collimated laser beam onto the workpiece surface to form a laser irradiation area for laser preheating; the protective lens... 4. This is used to isolate the influence of smoke and splash particles generated in the processing area on the aligning mirror 2 and focusing mirror 3 while maintaining laser transmission, thereby reducing the risk of surface contamination and damage. The hollow piezoelectric ceramic stack 15, the first end clamping member 15-1, the hollow pre-tightening bolt 15-2, the second end clamping member 15-3, the hollow multi-section cascaded amplitude transformer 7, and the hollow multi-ball array rolling head are arranged along the same central axis and form a central channel that runs through the working head. The first air intake branch 19-1 is connected to the central channel, and the second air intake branch 19-2 is connected to the annular cavity formed between the hollow annular voice coil motor 5 and the outer shell 18. Further, a partition is provided in the inner cavity of the outer shell 18 between the hollow annular voice coil motor 5 and the focusing mirror mount 12. The partition separates the area where the optical components are located in the outer shell 18 from the area where the hollow annular voice coil motor 5 is located along the axial direction. The center of the partition is provided with a central through hole that communicates with the central channel. The protective gas introduced through the first air intake branch 19-1 and the laser beam output from the laser 21 both enter the central channel through the central through hole and are transmitted towards the processing area along the central channel. By setting the partition, the area where the optical components are located can be separated from the area where the hollow ring voice coil motor 5 is located, and the protective gas and the laser beam can be transmitted along the same central channel through the central through hole.The hollow annular voice coil motor 5 includes a stator and a mover. The stator is rigidly fixed to the outer casing 18, and the mover is rigidly fixed to the upper base 16 of the coarse spring, and can move axially relative to the stator and the outer casing 18 along the central axis. The two ends of the coarse buffer spring 14 abut or are fixed to the upper base 16 and the lower base 17 of the coarse spring, respectively. The axial bearing end of the lower base 17 of the coarse spring abuts against the first end clamping member 15-1, and the lower base 17 of the coarse spring is not fixedly connected to the outer casing 18. The first end clamping member 15-1 is located at the end of the hollow piezoelectric ceramic stack 15 near the lower base 17 of the coarse spring, and the second end clamping member 15-3 is located at the end of the hollow piezoelectric ceramic stack 15 near the hollow multi-section cascaded amplitude transformer 7. The piezoelectric ceramic stack 15 is clamped between the first end clamping member 15-1 and the second end clamping member 15-3. The hollow preload bolt 15-2 is a slender hollow tie rod with limited axial stiffness. One end of the bolt is provided with a bolt head that presses against the first end clamping member 15-1, and the other end is threadedly connected to the axial threaded hole of the second end clamping member 15-3. After tightening the hollow preload bolt 15-2, the rod of the hollow preload bolt 15-2 is in an axially stretched state, and the hollow piezoelectric ceramic stack 15 is in an axially compressed preloaded state. When the hollow piezoelectric ceramic stack 15 elongates or contracts axially under the action of alternating voltage, the rod of the hollow preload bolt 15-2 undergoes corresponding elastic elongation or retraction to allow the first end clamping member 15-1 and the second end clamping member 15-3 to be clamped together. Axial micro-displacement is generated between the end clamping members 15-3, and the hollow piezoelectric ceramic stack 15 is kept in compression contact during operation; the second end clamping member 15-3 is rigidly connected to the input end of the hollow multi-section cascaded amplitude transformer 7, and the output end of the hollow multi-section cascaded amplitude transformer 7 is rigidly connected to the hollow multi-ball array rolling head; the flange 20 is sleeved on the outer periphery of the hollow multi-section cascaded amplitude transformer 7 and fixedly connected to it; the axial force generated by the hollow ring voice coil motor 5 is sequentially transmitted to the hollow multi-section cascaded amplitude transformer 7 and the first end clamping member 15-1, the hollow piezoelectric ceramic stack 15 in the compression pre-tightening state, and the second end clamping member 15-3 through the upper base 16 of the coarse spring 14, the lower base 17 of the coarse spring 17, the first end clamping member 15-1, the hollow piezoelectric ceramic stack 15 in the compression pre-tightening state, and the second end clamping member 15-3. A hollow multi-ball array rolling head is used to establish and adjust the rolling static pressure between the hollow multi-ball array rolling head and the workpiece surface; the hollow piezoelectric ceramic stack 15 is electrically connected to the ultrasonic power supply and generates axial periodic expansion and contraction displacement under the action of alternating voltage. The axial periodic expansion and contraction displacement is directly transmitted to the hollow multi-section cascaded amplitude transformer 7 and the hollow multi-ball array rolling head through the second end clamping member 15-3; the hollow multi-ball array rolling head is provided with a central through hole communicating with the central channel and includes multiple array balls 8; along the feed direction of the working head relative to the workpiece, at least one effective rolling contact point of the array ball 8 is located behind the laser irradiation area, so that the same position on the workpiece surface passes through the laser irradiation area first and then enters the effective rolling contact point.

[0031] like Figure 4As shown, the hollow multi-ball array rolling head includes array balls 8, an annular end face 9 of the rolling head, and an annular retainer 10. The annular end face 9 of the rolling head is provided with multiple ball sockets around the central through hole. The multiple array balls 8 are arranged circumferentially in the ball sockets along the annular end face 9 of the rolling head and are limited by the annular retainer 10. The collimating lens 2 is mounted on the collimating lens mount 11, and the focusing lens 3 is mounted on the focusing lens mount 12.

[0032] like Figure 3 As shown, along the central axis, a coarse spring upper base 16 is provided on the side of the hollow annular voice coil motor 5 near the hollow multi-section cascaded amplitude transformer 7. The coarse buffer spring 14 is provided between the coarse spring upper base 16 and the coarse spring lower base 17. The leaf spring flange 13 is fixed to the outer shell 18. The planar flexible leaf spring 6 has elastic compliance in the axial direction and is constrained in the radial direction. One end of the leaf spring 6 is fixedly connected to the leaf spring flange 13, and the other end is fixedly connected to the flange 20, so as to allow the hollow multi-section cascaded amplitude transformer 7 to generate axial elastic displacement relative to the outer shell 18 and limit its radial offset.

[0033] like Figure 2 As shown, the coarse spring lower base 17 is a hollow cylindrical base body arranged around the central axis. The end of the coarse spring lower base 17 facing the coarse buffer spring 14 has an axial end face that abuts against the coarse buffer spring 14, and the end facing the first end clamping member 15-1 has an axial end face that abuts against the first end clamping member 15-1 coaxially. There is a clearance space between the coarse spring lower base 17, the leaf spring flange 13, and the planar flexible leaf spring 6 to allow the coarse spring lower base 17 to move relative to the outer shell 18 along the central axis.

[0034] like Figure 5As shown, the hollow multi-section cascaded amplitude transformer 7 is a continuous hollow rod body integrally machined, and is sequentially divided into N consecutive acoustic half-wavelength segments (7-1, 7-2, 7-3...7-N) along the central axis. The acoustic half-wavelength segments are acoustic segments within the same rod body, not separate mechanical parts. The interface between adjacent acoustic half-wavelength segments is a longitudinal displacement nodal surface, which is sequentially marked as N1, N2, N3, N4 and subsequent nodal surfaces along the output end to the input end of the hollow multi-section cascaded amplitude transformer 7. The axial distance between adjacent longitudinal displacement nodal surfaces is half of the longitudinal wavelength λ corresponding to the working ultrasonic frequency. The outer wheel of the hollow multi-section cascaded amplitude transformer 7 The inner diameter maintains a constant radius along the axial direction. Based on this, the inner diameter gradually increases from the input end near the second end clamping member 15-3 to the output end near the hollow multi-ball array rolling head, making the effective annular cross-sectional area of ​​the rod wall at the output end smaller than that at the input end. This forms a reduced cross-sectional amplitude structure from the input end to the output end, which is beneficial to improving the longitudinal vibration displacement amplitude at the output end of the hollow multi-ball array rolling head. The flange 20 is fitted and fixed in the installation area including N4. The flange installation area where N4 is located retains a support section with a constant inner diameter along the axial direction, so that the flange 20 and the inner diameter transition area are staggered. Wherein, N is a positive integer.

[0035] like Figure 1 As shown, it also includes an external connecting base 1 disposed on the end of the housing 18 away from the hollow multi-ball array rolling head, for detachable connection with the external posture execution device 25; the external connecting base 1 is provided with an installation structure for connecting with the external posture execution device 25.

[0036] The hollow piezoelectric ceramic stack 15 is composed of multiple hollow annular piezoelectric ceramic units stacked sequentially along the central axis, and the piezoelectric material of each piezoelectric ceramic unit is lead zirconate titanate.

[0037] This invention discloses a laser-assisted adaptive ultrasonic micro-rolling processing method, comprising the following steps: S1, as Figure 6 As shown, the working head is mounted on the external posture execution device 25 via the external connection base 1. The output beam of the laser 21, which is matched with the working head, is coupled to the central channel of the working head through the collimating lens 2, focusing lens 3, and protective lens 4 to form a laser irradiation area. The voice coil motor drive power supply 22, ultrasonic power supply 23, and protective gas source 24, which are matched with the working head, are respectively connected to the hollow ring voice coil motor 5, the hollow piezoelectric ceramic stack 15, the first air intake branch 19-1, and the second air intake branch 19-2. According to the workpiece material, workpiece surface condition, target rolling static pressure, and processing trajectory, and in conjunction with the pre-calibrated process parameter correspondence, the drive current of the hollow ring voice coil motor 5 and the output power of the laser 21 are set. and the feed rate of the working head Among them, optical path transmission efficiency Pre-calibration is performed by measuring the optical power from the output end of laser 21 to the workpiece surface, and the incident laser power reaching the workpiece surface is then determined. Determined by the following formula: Formula (1) In the formula, The incident laser power reaching the workpiece surface, The optical power at the output of laser 21 To determine the optical path transmission efficiency from the output of laser 21 to the workpiece surface, and ; S2, turn on the protective air source 24, so that the first protective air enters the central channel through the air intake channel 19-1 and is discharged to the processing area through the central through hole of the hollow multi-ball array rolling head; so that the second protective air enters the outer space of the hollow annular voice coil motor 5 through the air intake channel 19-2 and is discharged to the processing area through the annular gap between the outer shell 18 and the hollow multi-section cascaded amplitude transformer 7; the external posture execution device 25 moves the working head to the processing start position; S3, with the hollow pre-tightening bolt 15-2 maintaining the axial compression pre-tightening of the hollow piezoelectric ceramic stack 15, the voice coil motor drive power supply 22 drives the mover of the hollow ring voice coil motor 5, so that the axial force is transmitted sequentially through the upper base 16 of the coarse spring, the coarse buffer spring 14, the lower base 17 of the coarse spring, the first end clamping member 15-1, the hollow piezoelectric ceramic stack 15 and the second end clamping member 15-3 to the hollow multi-section cascaded amplitude transformer 7 and the array ball bearings 8, and a predetermined rolling static pressure is established between the array ball bearings 8 and the workpiece surface; the flange 20, the planar flexible leaf spring 6 and the leaf spring flange 13 provide radial guidance and anti-overturning restraint for the hollow multi-section cascaded amplitude transformer 7; S4, an alternating voltage is applied to the hollow piezoelectric ceramic stack 15 by the ultrasonic power supply 23, causing the hollow piezoelectric ceramic stack 15 to generate periodic expansion and contraction displacement along the central axis, which is transmitted to the hollow multi-section cascaded amplitude transformer 7 and the hollow multi-ball array rolling head through the second end clamping member 15-3; at the same time, the laser 21 is turned on, and the external posture execution device 25 drives the working head to feed continuously, so that the effective rolling contact point of the array balls 8 is located on the rear side of the laser irradiation area along the feed direction, so that the same position on the workpiece surface first passes through the laser irradiation area, and then enters the effective rolling contact point of the array balls 8 for ultrasonic micro-rolling; during the processing, the coarse buffer spring 14 and the planar flexible leaf spring 6 together allow the hollow multi-section cascaded amplitude transformer 7 and the hollow multi-ball array rolling head to generate axial micro-displacement relative to the outer shell 18 to adapt to the local axial undulations of the workpiece surface; the planar flexible leaf spring 6 also restricts the radial offset and overturning of the hollow multi-section cascaded amplitude transformer 7; S5, when the processing is finished, first turn off the laser 21, then stop the processing feed of the working head, and keep the protective gas source 24 on; then turn off the ultrasonic power supply 23, gradually reduce the driving current of the hollow ring voice coil motor 5 to zero, so as to gradually release the rolling static pressure between the array ball 8 and the workpiece surface and stop driving the hollow ring voice coil motor 5; then the external posture execution device 25 drives the working head to detach from the workpiece surface and exit the processing area; after continuing to introduce protective gas for purging, the protective gas source 24 is turned off.

[0038] Under the condition that the hollow piezoelectric ceramic stack 15 is not subjected to ultrasonic excitation, the laser 21 is not outputting laser light, and all parts are in the same pre-tightened assembly state as in actual working condition, the thrust constant of the hollow ring voice coil motor 5 is... Elastic reaction force and equivalent axial stiffness Pre-calibration is performed; the mover of the hollow toroidal voice coil motor 5 is axially constrained to the calibration fixture, and different drive currents are applied. , Using an external calibration fixture independent of the working head, under the actual assembly preload state and predetermined working position of the working head, a force sensor is set along the axial force direction of the moving element of the hollow annular voice coil motor 5 to measure the corresponding axial force of the voice coil motor. , The thrust constant Determined by the following formula: Formula (2) With the hollow toroidal voice coil motor 5 de-energized and the hollow piezoelectric ceramic stack 15 not subjected to ultrasonic excitation, the flange 20 is made to have different relative axial displacements relative to the fixed leaf spring flange 13 along the central axis of the working head by means of a calibration fixture, and the relative axial displacements are measured by a displacement measuring device. The elastic reaction force generated by the coarse buffer spring 14 and the planar flexible leaf spring 6 is measured by the force sensor. Elastic reaction force at the reference position and equivalent axial stiffness They are determined by the following formulas respectively: Formula (3) Formula (4) in, The elastic reaction force generated by the coarse buffer spring 14 and the planar flexible leaf spring 6 when the flange 20 is in the reference position; and The flange 20 generates relative axial displacement with respect to the leaf spring flange 13. and The elastic reaction force generated by the coarse buffer spring 14 and the planar flexible leaf spring 6; and These are two unequal relative axial displacements.

[0039] Substitute the predetermined working displacement range The elastic reaction force is determined by the following formula: Formula (5) The axial force of the hollow toroidal voice coil motor 5 is determined by the following formula: Formula (6) in, This is the actual driving current applied to the hollow ring voice coil motor 5; Based on the workpiece material, the diameter and number of balls in the array 8, the expected amount of plastic deformation, and the surface finish requirements, the target axial force transmitted to the array 8 is directly determined through the pre-established correspondence between process parameters and processing effects. The driving current of the hollow toroidal voice coil motor 5 is determined according to the following formula. : Formula (7) Formula (8) In the formula, This is the thrust constant of the voice coil motor. This refers to the actual driving current applied to the hollow toroidal voice coil motor 5. The axial force generated by the driving current. The equivalent elastic reaction force generated by the coarse buffer spring 14 and the planar flexible leaf spring 6, This is the elastic reaction force when flange 20 is in the reference position. The equivalent axial stiffness of the coarse buffer spring 14 and the planar flexible leaf spring 6, The target axial force corresponds to the target rolling static pressure. This refers to the relative axial displacement of flange 20 relative to leaf spring flange 13; when setting the drive current, The target working displacement is preset, and its positive direction is the direction in which the array of balls 8 press against the workpiece.

[0040] Under the conditions that the installation positions of collimating lens 2, focusing lens 3, and protective lens 4, the focal length of the working head relative to the workpiece, and the surface condition of the workpiece are determined, the positions of the laser spot at the workpiece surface along the feed direction of the workpiece surface are measured. and To determine the equivalent laser spot width : Formula (9) The directional projection distance from the intersection of the central channel optical axis and the workpiece surface to the effective rolling contact point of the selected array of balls 8 located behind the feed direction along the feed direction of the workpiece surface is: Incident laser energy per unit area of ​​the workpiece surface Determined by the following formula: Formula (10) Under the same workpiece material, surface condition, optical path, and protective gas conditions as in actual processing, a pre-laser thermal response calibration test was conducted to determine the workpiece surface temperature at the corresponding position of the effective rolling contact point that meets the requirements. Target unit area incident laser energy and target thermal delay time ; working head feed rate Determined by the following formula: Formula (11) The incident laser energy per unit area Equal to the incident laser energy per unit area of ​​the target The output power of the laser (21) Determined by the following formula: Formula (12) In the formula, and These represent the two boundary positions of the laser spot along the feed direction on the workpiece surface. The equivalent laser spot width, The directional projection distance from the laser irradiation area to the effective rolling contact point. The incident laser energy per unit area of ​​the workpiece surface. The target incident laser energy per unit area is determined through a pre-determined laser thermal response calibration test. The target thermal delay time is determined through the pre-laser thermal response calibration test. For the working head feed speed, The incident laser power reaching the workpiece surface, The optical power at the output of laser 21 For optical path transmission efficiency, The temperature of the workpiece surface at the effective rolling contact point after the thermal delay time. This refers to the workpiece's thermal softening temperature. The melting temperature of the workpiece is denoted as , and , , and .

Claims

1. A laser-assisted adaptive ultrasonic micro-rolling head, characterized in that, Includes a housing (18), a protective lens (4), a collimating lens (2), a focusing lens (3), a first air intake branch (19-1), a second air intake branch (19-2), a hollow ring voice coil motor (5), a coarse spring upper base (16), a coarse buffer spring (14), a coarse spring lower base (17), a first end clamping piece (15-1), a hollow piezoelectric ceramic stack (15), a hollow preload bolt (15-2), a second end clamping piece (15-3), a leaf spring flange (13), a planar flexible leaf spring (6), a flange (20), a hollow multi-section cascaded amplitude transformer (7), and a hollow multi-ball array rolling head; the collimating lens (2), the focusing lens (3), and the protective lens (4) are located sequentially on the central optical axis, and the hollow piezoelectric ceramic stack ( 15) The first end clamping member (15-1), the hollow pre-tightening bolt (15-2), the second end clamping member (15-3), the hollow multi-section cascaded amplitude transformer (7), and the hollow multi-ball array rolling head are arranged along the same central axis and form a central channel through the working head; the first air intake branch (19-1) is connected to the central channel, and the second air intake branch (19-2) is connected to the annular cavity formed between the hollow ring voice coil motor (5) and the outer shell (18); the hollow ring voice coil motor (5) includes a stator and a mover, the stator is rigidly fixed to the outer shell (18), and the mover is rigidly connected to the base (16) of the coarse spring and can move axially relative to the stator and the outer shell (18) along the central axis; coarse buffer The two ends of the spring (14) abut or are fixed to the upper base (16) and the lower base (17) of the coarse spring, respectively; the axial bearing end of the lower base (17) of the coarse spring abuts against the first end clamping member (15-1), and the lower base (17) of the coarse spring is not fixedly connected to the outer shell (18); the first end clamping member (15-1) is located at the end of the hollow piezoelectric ceramic stack (15) near the lower base (17) of the coarse spring, and the second end clamping member (15-3) is located at the end of the hollow piezoelectric ceramic stack (15) near the hollow multi-section cascaded amplitude transformer (7), and the hollow piezoelectric ceramic stack (15) is clamped between the first end clamping member (15-1) and the second end clamping member (15-3); the hollow preload bolt (15-2) has limited axial stiffness. The slender hollow tie rod has a bolt head at one end that presses against the first end clamping member (15-1), and the other end is threadedly connected to the axial threaded hole of the second end clamping member (15-3). After tightening the hollow pre-tightening bolt (15-2), the rod of the hollow pre-tightening bolt (15-2) is in an axially stretched state, and the hollow piezoelectric ceramic stack (15) is in an axially compressed pre-tightened state. When the hollow piezoelectric ceramic stack (15) elongates or contracts axially under the action of alternating voltage, the rod of the hollow pre-tightening bolt (15-2) undergoes corresponding elastic elongation or retraction, so as to allow axial micro-displacement between the first end clamping member (15-1) and the second end clamping member (15-3), and keep the hollow piezoelectric ceramic stack (15) in compressed contact during operation.The second end clamping member (15-3) is rigidly connected to the input end of the hollow multi-section cascaded amplitude transformer (7), and the output end of the hollow multi-section cascaded amplitude transformer (7) is rigidly connected to the hollow multi-ball array rolling head; the flange (20) is sleeved on the outer periphery of the hollow multi-section cascaded amplitude transformer (7) and fixedly connected to it; the axial force generated by the hollow ring voice coil motor (5) is transmitted sequentially through the upper base (16) of the coarse spring (14), the lower base (17) of the coarse spring, the first end clamping member (15-1), the hollow piezoelectric ceramic stack (15) in the compressed pre-tightening state, and the second end clamping member (15-3) to the hollow multi-section cascaded amplitude transformer (7) and the hollow multi-ball array rolling head to establish The static pressure of rolling between the hollow multi-ball array rolling head and the workpiece surface is adjusted; the hollow piezoelectric ceramic stack (15) is electrically connected to the ultrasonic power supply and generates axial periodic expansion and contraction displacement under the action of alternating voltage. The axial periodic expansion and contraction displacement is directly transmitted to the hollow multi-section cascaded amplitude transformer (7) and the hollow multi-ball array rolling head through the second end clamping part (15-3); the hollow multi-ball array rolling head is provided with a central through hole communicating with the central channel and includes multiple array balls (8); along the feed direction of the working head relative to the workpiece, the effective rolling contact point of at least one array ball (8) is located behind the laser irradiation area, so that the same position on the workpiece surface passes through the laser irradiation area first and then enters the effective rolling contact point.

2. The working head according to claim 1, characterized in that, The hollow multi-ball array rolling head includes array balls (8), an annular end face (9) of the rolling head and an annular retainer (10). The annular end face (9) of the rolling head is provided with multiple ball sockets around the central through hole. The multiple array balls (8) are arranged in the ball sockets at intervals along the circumference of the annular end face (9) of the rolling head and are limited by the annular retainer (10). The collimating lens (2) is mounted on the collimating lens mount (11) and the focusing lens (3) is mounted on the focusing lens mount (12).

3. The working head according to claim 1, characterized in that, Along the central axis, a coarse spring upper base (16) is provided on the side of the hollow annular voice coil motor (5) near the hollow multi-section cascaded amplitude transformer (7). The coarse buffer spring (14) is provided between the coarse spring upper base (16) and the coarse spring lower base (17). The leaf spring flange (13) is fixed on the outer shell (18). The planar flexible leaf spring (6) has elastic compliance in the axial direction and is constrained in the radial direction. One end of the leaf spring is fixedly connected to the leaf spring flange (13), and the other end is fixedly connected to the flange (20) to allow the hollow multi-section cascaded amplitude transformer (7) to generate axial elastic displacement relative to the outer shell (18) and limit its radial offset.

4. The working head according to claim 1, characterized in that, The lower base of the coarse spring (17) is a hollow cylindrical seat body arranged around the central axis. The end of the lower base of the coarse spring (17) facing the coarse buffer spring (14) has an axial end face that abuts against the coarse buffer spring (14), and the end facing the first end clamping member (15-1) has an axial end face that abuts against the first end clamping member (15-1) coaxially. There is a clearance space between the lower base of the coarse spring (17), the leaf spring flange (13), and the planar flexible leaf spring (6) to allow the lower base of the coarse spring (17) to move relative to the outer shell (18) along the central axis.

5. The laser-assisted adaptive ultrasonic micro-rolling head according to claim 1, characterized in that, The hollow multi-section cascaded amplitude transformer (7) is a continuous hollow rod body formed by integral processing. It is divided into N continuous acoustic half-wavelength segments along the central axis. The acoustic half-wavelength segments are acoustic segments within the same rod body and are not separate mechanical parts. The interface between adjacent acoustic half-wavelength segments is a longitudinal displacement nodal surface. The axial distance between adjacent longitudinal displacement nodal surfaces is half of the longitudinal wavelength λ corresponding to the working ultrasonic frequency. The outer contour of the hollow multi-section cascaded amplitude transformer (7) maintains a constant radius along the axial direction. On this basis, the inner hole radius gradually increases from the input end near the second end clamping member (15-3) to the output end near the hollow multi-ball array rolling head, so that the effective annular cross-sectional area of ​​the rod wall at the output end is smaller than that at the input end, thereby forming a reduced cross-section amplitude transformer structure from the input end to the output end, which is beneficial to improving the longitudinal vibration displacement amplitude at the output end of the hollow multi-ball array rolling head. Wherein, N is a positive integer.

6. The working head according to claim 1, characterized in that, It also includes an external connecting base (1) disposed on the end of the housing (18) away from the hollow multi-ball array rolling head, for detachable connection with the external posture execution device (25); the external connecting base (1) is provided with an installation structure for connection with the external posture execution device (25).

7. The working head according to claim 1, characterized in that, The hollow piezoelectric ceramic stack (15) is composed of multiple hollow annular piezoelectric ceramic units stacked sequentially along the central axis, and the piezoelectric material of each piezoelectric ceramic unit is lead zirconate titanate.

8. A laser-assisted adaptive ultrasonic micro-rolling processing method, characterized in that, The laser-assisted adaptive ultrasonic micro-rolling head according to any one of claims 1 to 7 comprises the following steps: S1, the working head is installed on the external posture execution device (25) through the external connection base (1). The output beam of the laser (21) matched with the working head is coupled to the central channel of the working head to form a laser irradiation area after passing through the collimating lens (2), the focusing lens (3) and the protective lens (4). The voice coil motor drive power supply (22), the ultrasonic power supply (23) and the protective gas source (24) matched with the working head are connected to the hollow ring voice coil motor (5), the hollow piezoelectric ceramic stack (15) and the first air intake branch (19-1) and the second air intake branch (19-2) respectively. According to the workpiece material, the workpiece surface condition, the target rolling static pressure and the processing trajectory, and in combination with the pre-calibrated process parameter correspondence, the driving current of the hollow ring voice coil motor (5) and the output power of the laser (21) are set. and the feed rate of the working head Among them, optical path transmission efficiency Pre-calibration is performed by measuring the optical power from the output end of the laser (21) to the surface of the workpiece, and the incident laser power reaching the surface of the workpiece is then determined. Determined by the following formula: Formula (1) In the formula, The incident laser power reaching the workpiece surface, The optical power at the output of the laser (21) is... For the optical path transmission efficiency from the output end of the laser (21) to the surface of the workpiece, and ; S2, turn on the protective air source (24), so that the first protective air enters the central channel through the air intake channel (19-1) and is discharged to the processing area through the central through hole of the hollow multi-ball array rolling head, so that the second protective air enters the outer space of the hollow ring voice coil motor (5) through the air intake channel (19-2) and is discharged to the processing area through the annular gap between the outer shell (18) and the hollow multi-section cascaded amplitude transformer (7); the external posture execution device (25) moves the working head to the processing start position; S3, with the hollow pre-tightening bolt (15-2) maintaining the hollow piezoelectric ceramic stack (15) under axial compression pre-tightening, the voice coil motor drive power supply (22) drives the mover of the hollow ring voice coil motor (5), so that the axial force is transmitted sequentially through the upper base of the coarse spring (16), the coarse buffer spring (14), the lower base of the coarse spring (17), the first end clamping member (15-1), the hollow piezoelectric ceramic stack (15), and the second end clamping member (15-3) to the hollow multi-section cascaded amplitude transformer (7) and the array ball (8), and a predetermined rolling static pressure is established between the array ball (8) and the workpiece surface; the flange (20), the planar flexible leaf spring (6), and the leaf spring flange (13) provide radial guidance and anti-overturning constraint for the hollow multi-section cascaded amplitude transformer (7); S4, an alternating voltage is applied to the hollow piezoelectric ceramic stack (15) by the ultrasonic power supply (23), causing the hollow piezoelectric ceramic stack (15) to generate periodic expansion and contraction displacement along the central axis, which is transmitted to the hollow multi-section cascaded amplitude transformer (7) and the hollow multi-ball array rolling head through the second end clamping member (15-3); at the same time, the laser (21) is turned on, and the external posture execution device (25) drives the working head to feed continuously, so that the effective rolling contact point of the array balls (8) is located on the rear side of the laser irradiation area along the feed direction, thereby making The same position on the workpiece surface first passes through the laser irradiation area, and then enters the effective rolling contact point of the array ball (8) for ultrasonic micro-rolling; during the processing, the coarse buffer spring (14) and the planar flexible leaf spring (6) in the axial elastic deformation together allow the hollow multi-section cascaded amplitude transformer (7) and the hollow multi-ball array rolling head to generate axial micro-displacement relative to the shell (18) to adapt to the local axial undulation of the workpiece surface; the planar flexible leaf spring (6) at the same time restricts the radial offset and overturning of the hollow multi-section cascaded amplitude transformer (7); S5, when the processing is finished, first turn off the laser (21), then stop the processing feed of the working head, and keep the protective gas source (24) on; then turn off the ultrasonic power supply (23), gradually reduce the driving current of the hollow ring voice coil motor (5) to zero, so as to gradually release the rolling static pressure between the array ball (8) and the workpiece surface and stop driving the hollow ring voice coil motor (5); then the external posture execution device (25) drives the working head to detach from the workpiece surface and exit the processing area; after continuing to introduce protective gas for purging, turn off the protective gas source (24).

9. The processing method according to claim 8, characterized in that, The thrust constant of the hollow piezoelectric ceramic stack (15) is measured under the following conditions: no ultrasonic excitation is applied to the hollow piezoelectric ceramic stack (15), no laser is output from the laser (21), and all parts are in the same pre-tightened assembly state as in actual operation. Elastic reaction force and equivalent axial stiffness Perform pre-calibration; The mover of the hollow toroidal voice coil motor (5) is constrained axially to the calibration fixture, and different drive currents are applied. , Under the following conditions, an external calibration fixture independent of the working head is used. In the actual assembly preload state and predetermined working position of the working head, the force sensor is set along the axial force direction of the moving part of the hollow annular voice coil motor (5) to measure the corresponding axial force of the voice coil motor. , The thrust constant Determined by the following formula: Official (2) Under the condition that the hollow toroidal voice coil motor (5) is not energized and the hollow piezoelectric ceramic stack (15) is not subjected to ultrasonic excitation, the flange (20) is made to have different relative axial displacements relative to the fixed leaf spring flange (13) along the central axis of the working head by means of calibration fixture, and the relative axial displacements are measured by displacement measuring device. The elastic reaction forces generated by the coarse buffer spring (14) and the planar flexible leaf spring (6) were measured by a force sensor. Elastic reaction force at the reference position and equivalent axial stiffness They are determined by the following formulas respectively: Official (3) Official (4) in, The elastic reaction force generated by the coarse buffer spring (14) and the planar flexible leaf spring (6) when the flange (20) is in the reference position; and The flange (20) generates a relative axial displacement with respect to the leaf spring flange (13). and The elastic reaction force generated by the coarse buffer spring (14) and the planar flexible leaf spring (6); and These are two unequal relative axial displacements. Substitute the predetermined working displacement range The elastic reaction force is determined by the following formula: Official (5) The axial force of the hollow toroidal voice coil motor (5) is determined by the following formula: Official (6) in, The actual driving current applied to the hollow ring voice coil motor (5); Based on the workpiece material, the diameter and number of balls in the array (8), the expected amount of plastic deformation, and the surface finish requirements, the target axial force transmitted to the array (8) is directly determined through the pre-established correspondence between process parameters and processing effects. The driving current of the hollow toroidal voice coil motor (5) is determined according to the following formula. : Official (7) Official (8).

10. The processing method according to claim 8, characterized in that, Under the conditions that the installation positions of the collimating lens (2), focusing lens (3) and protective lens (4), the focal length of the working head relative to the workpiece, and the surface condition of the workpiece are determined, the two boundary positions of the laser spot on the workpiece surface along the feed direction of the workpiece surface are measured. and To determine the equivalent laser spot width : Official (9) The directional projection distance from the intersection of the central channel optical axis and the workpiece surface to the effective rolling contact point of the selected array of balls (8) located behind the feed direction along the workpiece surface is: Incident laser energy per unit area of ​​the workpiece surface Determined by the following formula: Equation (10) Under the same workpiece material, surface condition, optical path, and protective gas conditions as in actual processing, a pre-laser thermal response calibration test was conducted to determine the workpiece surface temperature at the corresponding position of the effective rolling contact point that meets the requirements. Target unit area incident laser energy and target thermal delay time ; working head feed rate Determined by the following formula: Official (11) The incident laser energy per unit area Equal to the incident laser energy per unit area of ​​the target The output power of the laser (21) Determined by the following formula: Official (12) In the formula, The incident laser energy per unit area is determined through a pre-tested laser thermal response calibration.

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