Workpiece Five-Axis Adjustment Frame, Five-Axis Motion Device, Laser Processing System and Method

Abstract

The present invention discloses a five-axis adjustment frame for workpieces, a five-axis motion device, a laser processing system and a method, belonging to the field of laser processing. By means of different adjustment units, forces in different directions are applied to the positioning disc, so as to change the pitch angle and spatial position of the workpiece, realizing high-precision pose adjustment of the workpiece, and thus enabling the axes of the double rotary tables, the curvature center of the workpiece and the laser optical axis to achieve high-precision coincidence. Through the coordinated control of the A-axis rotary table and the B-axis rotary table, by utilizing the rotation characteristics of the workpiece to be processed, a processing method is adopted in which the position of the laser focus remains fixed and the workpiece rotates at high speed and with high precision. During the processing process, it is not necessary to control the lifting of the Z-axis, and the focusing accuracy error caused by the change of the optical path scanning is eliminated. The A-axis rotary table and the B-axis rotary table drive the workpiece to perform spatial rotation, and the rotation angle and speed are determined by the graph to be processed, realizing the high-precision and high-speed processing of the set graph on the surface of the workpiece.

Description

Technical Field

[0001] The present invention belongs to the field of laser processing, and more specifically, relates to a five-axis adjustment frame for a workpiece, a five-axis motion device, a laser processing system, and a method. Background Art

[0002] With the continuous development of global industrial processing and manufacturing technologies, the demand for material processing in various fields has evolved from two-dimensional planes to three-dimensional curved surfaces. For the processing of rotational curved surfaces such as spherical surfaces, cylindrical surfaces, and conical surfaces, two methods are often employed:

[0003] One is the traditional mechanical processing method of special masks and ion etching to etch the required patterns on the surface of the workpiece to be processed. The disadvantage of this processing method is that the processing accuracy of the pattern depends on the processing accuracy of the mask. However, mask materials are often thin, prone to deformation, and have disadvantages such as difficult control of pattern parameters, long processing time, and high requirements for tools.

[0004] The other is to use the laser method to etch the surface of the workpiece to be processed. Usually, a galvanometer can be used for precise scanning within a two-dimensional plane. By adjusting the displacement of the workpiece or the laser beam, a three-dimensional scan can be achieved by making the focused position of the laser beam on the workpiece form a three-dimensional scan, thereby realizing the processing of the curved surface. However, this method also has disadvantages such as uneven spot distribution caused by changes in the focal plane and the beam not being strictly perpendicular to the processing surface due to the deflection of the galvanometer.

[0005] Patent CN103266323A discloses a method for surface etching processing of metal products with curved surface structures. First, mask treatment is performed on the flat part and the curved part of the metal product. The mask gap of the flat part is uniform and consistent, and the mask gap of the curved part gradually increases from the junction of the flat surface and the curved surface to the edge of the curved surface. Then, a corrosion-resistant blocker is used to block the curved part of the metal product along the direction parallel to the flat surface of the metal product, and then etching processing is carried out. This etching processing method has a cumbersome process. After the initial etching, subsequent processing processes such as demasking, re-etching, soaking, and cleaning are required. Moreover, the etching solution, corrosion-resistant glue, cleaning solution, etc. used are all chemical products, which will cause certain pollution to the environment. Since the processed pattern is formed by the chemical reaction between the etching solution and the metal surface, there is uncontrollability. Areas that need to be processed may not be etched due to the inadequacy of the chemical reaction, or areas that do not need to be processed may be etched due to the influence of the chemical reaction, and the etching processing effect will be affected to a certain extent.

[0006] Patent CN109940270A discloses a seven-axis five-linkage ultra-fast laser processing system. In this method, the workpiece to be processed is placed on a rotating table. By projecting structured light onto the workpiece and taking pictures for feedback, the deflection of the optical path is then modified. Then, a galvanometer is used to scan the workpiece. The principle of realizing curved surface processing in this method is to adjust the position of the workpiece through the rotating table, and then use the galvanometer to perform planar scanning within a small scanning field. In fact, the curved surface is divided into small planes, and the continuity of the curved surface is not high. Moreover, by taking pictures of the structured light and feeding back to the computer to modify the optical path, it will actually still cause a certain degree of uneven focusing.

[0007] Patent CN112475591A discloses a double swivel head type five-axis linkage laser processing machine tool and its working method. Two rotating tables are used to realize the curved surface processing of the workpiece. One rotating table is used to fix and rotate the workpiece to enable circumferential scanning of the workpiece, and the other rotating table is linked with the Z-axis displacement mechanism to realize the curved surface scanning of the laser through the swing of the laser head. In theory, this method can ensure that the laser focus is always on the surface to be processed in real time. However, due to the limitation of the Z-axis displacement mechanism, the scanning speed cannot be increased, and calibration is required before the linkage scanning. It is also difficult to ensure the coaxiality between the double rotating tables and the workpiece.

[0008] Patent CN206561203U discloses a five-axis laser cutting device suitable for helmet processing. First, the workpiece is placed on the material table for positioning, and then a pre-scan of the three-dimensional space of the workpiece is performed, and a processing path is formed through an algorithm. The rotation of the workpiece is realized through the translation and rotation of the material table, and the curved surface scanning of the workpiece surface is realized through the swing head of the laser beam and the Z-axis displacement mechanism. In theory, this method can realize that the laser focus is always on the surface to be processed in real time. However, the actual operation is relatively complex. The pre-scan affects the processing efficiency and accuracy. The translation and rotation of the material table limit the processing speed, and it is difficult to ensure the coaxial situation between the curvature center of the workpiece surface and the laser beam.

[0009] Patent CN210817953U discloses a five-axis laser micro-processing device based on a scanning galvanometer. The workpiece is fixed on a rotating table, and at the same time, rotation on the orthogonal plane is realized through another rotating table. When the double rotating tables act together, relatively complex curved surface processing can be realized through the galvanometer. This method uses the double rotating tables to enable the workpiece to have two orthogonal rotational degrees of freedom. In theory, high-efficiency and relatively high-precision curved surface processing can be realized. However, the disadvantage is that there is a lack of a specific device to make the axes of the double rotating tables, the curvature center of the workpiece, and the optical axis of the laser achieve a high-precision fit. When the multi-axis moves in coordination, tiny coaxial errors will be amplified, thus affecting the processing accuracy.

[0010] The problems existing in the above-mentioned disclosed curved surface forming devices and their surface etching are as follows:

[0011] 1. With traditional mechanical processing for making special masks and ion etching methods, the curved surface structures that can be fabricated are limited. For each curved surface structure to be made, a corresponding mold needs to be manufactured, which is a cumbersome process with high costs. For some complex curved surface structures, the processing difficulty coefficient of their molds is relatively high and they are not easy to fabricate. When etching the metal surface using chemical agents, due to the uncertainty and non-directionality of chemical reactions, the etching area and depth cannot be controlled, which will seriously degrade the processing quality. Moreover, for relatively small-sized curved surface metal materials, the difficulty of mask treatment increases significantly, and the chemical agents easily flow out from the area of the sample to be etched, resulting in the destruction of the sample.

[0012] 2. The quality of the surface processed by the galvanometer scanning laser etching method is not ideal. To improve the processing efficiency, currently most adopt the galvanometer scanning method. However, for a curved surface structure with a non-planar shape, there are certain differences in the foci of each area where the laser acts, resulting in different amounts of laser energy absorbed by the surface material in the acting areas, and thus different etching effects and a decline in etching quality. For the device using the galvanometer scanning method for laser etching, if a better etching effect is to be obtained, the shape of the processed metal surface needs to be a planar structure, which leads to limitations in the etching processing ability.

[0013] 3. The laser etching method using the linkage of a rotating table and a displacement mechanism has low efficiency. For the processing of the curved surface profile of a workpiece in the vertical plane, there is currently a method that uses a rotating table and a laser beam to construct a swing head, and then links it with the Z-axis displacement mechanism. When the Z-axis displacement mechanism moves downward, the swing head swings upward to scan and process the curved surface. However, the processing efficiency of this method is limited by the moving speed of the Z-axis displacement mechanism, and relatively complex calibration or pre-scanning is required before processing.

[0014] 4. The laser etching method using a double rotating table to control the multi-degree-of-freedom rotation of the workpiece is difficult to ensure the accuracy of positioning. This method actually utilizes the rotational characteristics of the workpiece to be processed, and realizes the real-time focusing of the laser on the curved surface of the workpiece by rotating the workpiece while keeping the laser optical path fixed. Since the laser optical path is fixed, as long as the rotation center of the workpiece is coaxial with the laser beam, it can ensure that the laser beam is always perpendicular to the plane to be processed, obtaining a high-quality focusing effect. However, when there is multi-axis coordinated movement, tiny coaxial errors will be amplified, and this processing method requires the high-precision alignment of the axes of the double rotating tables, the curvature center of the workpiece, and the laser optical axis.

[0015] In summary, there is an urgent need for a laser processing method and device for etching rotary curved surface workpieces, which have the advantages of high processing accuracy, fast processing efficiency, and good processing quality. Summary of the Invention

[0016] Aiming at the defects of the prior art, the purpose of the present invention is to provide a five-axis adjustment frame for workpieces, a five-axis motion device, a laser processing system and a method, aiming to solve the problems that the multi-axis coordinated motion in the existing processing methods is difficult to ensure the positioning accuracy and the etching efficiency is low.

[0017] To achieve the above object, in the first aspect, the present invention provides a five-axis adjustment frame for workpieces, including: an upper layer member, a lower layer member, a positioning disk, an angle adjustment unit, a displacement adjustment unit and a connection unit;

[0018] A groove is provided in the middle of the upper layer member;

[0019] The positioning disk is a frustum with a fixing member provided on its upper end surface, and the fixing member is used to fix the workpiece to be processed;

[0020] The upper layer member and the lower layer member are elastically connected and there is a gap in the middle, thus forming an installation cavity;

[0021] The positioning disk is arranged in the installation cavity, and its bottom surface is attached to the groove surface;

[0022] The angle adjustment unit penetrates the surface of the upper layer member and abuts against the upper surface of the lower layer member, and is used to adjust the pitching angle of the upper layer member in space;

[0023] The displacement adjustment unit penetrates the side surface of the upper layer member and abuts against the frustum of the positioning disk, and is used to adjust the relative position of the positioning frustum in space;

[0024] The connection unit penetrates the surface of the lower layer member and is used to fix the lower layer member and the B-axis rotating table.

[0025] Preferably, both the angle adjustment unit and the displacement adjustment unit are N screws, N≥3.

[0026] It should be noted that in the present invention, the angle or displacement is adjusted by multiple screws. By finely adjusting the rotation angle of the screws, the stepping distance can be adjusted, and the stepping amplitude can reach the sub-micron level, so as to extremely precisely adjust the pitching angle and displacement distance of the positioning disk.

[0027] Preferably, the N screws are evenly distributed at equal intervals.

[0028] It should be noted that the present invention preferably evenly distributes at equal intervals, which can make the weight of each adjustment the same, so as to minimize the number of adjustments as much as possible. At the same time, the equal-interval uniform distribution can improve the stability of the device and extend its service life.

[0029] Preferably, the angle adjustment range of the five-axis adjustment frame for workpieces is between 0° and 30°.

[0030] Preferably, the displacement adjustment range of the five-axis adjustment frame for workpieces is between 0.0001 mm and 10 mm.

[0031] Preferably, a fastening screw is provided on the side of the fixing member of the positioning disk.

[0032] It should be noted that providing a fastening screw on the side of the fixing member can accommodate workpieces of different sizes and perform fixing at different depths.

[0033] Preferably, an elastic connection is achieved between the upper member and the lower member through a pin and a spring. The two ends of the spring respectively pass through through-holes on the upper member and the lower member, and there are pin slots for placing the pin at the through-holes. The pin is used to keep the spring in a certain compressed or extended state.

[0034] To achieve the above object, in a second aspect, the present invention provides a five-axis motion device, including: a workpiece five-axis adjustment frame, an A-axis rotary table, a rotary table connecting member, a B-axis rotary table, and an XY-axis two-dimensional linear displacement platform as described in the first aspect;

[0035] The lower member of the workpiece five-axis adjustment frame is fixed to the B-axis rotary table;

[0036] The B-axis rotary table is used to drive the lower member to rotate around the B-axis perpendicular to the vertical plane;

[0037] The A-axis rotary table is used to drive the rotary table connecting member to rotate around the A-axis perpendicular to the horizontal plane, and the A-axis is parallel to the Z-axis direction;

[0038] The A-axis rotary table and the B-axis rotary table are orthogonally connected through the rotary table connecting member, so that the rotation center lines of the two rotary tables coincide at a point in space;

[0039] The A-axis rotary table is fixed on the XY-axis two-dimensional linear displacement platform;

[0040] The XY-axis two-dimensional linear displacement platform is used to drive the A-axis rotary table to perform translation in space.

[0041] To achieve the above object, in a third aspect, the present invention provides a five-axis laser processing system, including: the five-axis motion device as described in the second aspect, a laser light source, a laser beam expander, a fixed mirror, a liftable mirror, a laser focusing lens, a CCD camera, a contact displacement sensor, a Z-axis linear displacement platform, and a controller;

[0042] The laser light source is used to generate laser light entering the laser beam expander;

[0043] The laser beam expander is used to obtain a smaller spot size;

[0044] The fixed mirror and the liftable mirror are used to deflect and adjust the optical path;

[0045] The laser focusing lens is used to focus the spot on the surface of the workpiece to be processed;

[0046] The CCD camera is located on the same Z-axis linear displacement platform as the laser focusing lens and is used to find the spatial position of the laser focusing point.

[0047] The contact displacement sensor is located on the same Z-axis linear displacement platform as the laser focusing lens and is used to measure the side surface of the rotary table connecting piece.

[0048] The Z-axis linear displacement platform is used to drive the laser focusing lens fixed on the Z-axis linear displacement platform to perform vertical translational motion in space.

[0049] The controller is used to control the CCD camera and the contact displacement sensor for positioning, control the A-axis rotary table, B-axis rotary table, XY-axis two-dimensional linear displacement platform, and Z-axis linear displacement platform to move, and control the adjustment of the laser parameters of the laser light source.

[0050] To achieve the above object, in the fourth aspect, the present invention provides a processing method for a five-axis laser processing system as in the third aspect. The workpiece to be processed is a curved surface workpiece with a rotation center and is fixed on the B-axis rotary table through a workpiece five-axis adjustment frame. The method includes:

[0051] S1. Adjust the ball shaft and the rotating shaft of the B-axis rotary table to be coaxial:

[0052] Rotate the A-axis rotary table to ensure that the side surface of the rotary table connecting piece is perpendicular to the probe of the contact displacement sensor.

[0053] Place the probe of the contact displacement sensor at the root of the workpiece to be processed, rotate the B-axis rotary table, and read the indication of the contact displacement sensor at this time.

[0054] Adjust the displacement adjustment unit of the workpiece five-axis adjustment frame to perform displacement adjustment on the positioning disk until the indication of the contact displacement sensor remains unchanged when the B-axis rotary table rotates.

[0055] Place the probe of the contact displacement sensor on the surface of the workpiece to be processed, rotate the B-axis rotary table, and read the indication of the contact displacement sensor at this time.

[0056] Adjust the tilt angle of the positioning disk through the angle adjustment unit of the workpiece five-axis adjustment frame until the indication of the contact displacement sensor remains unchanged when the B-axis rotary table rotates.

[0057] Continuously repeat the above two steps until the adjustment accuracy of the root and surface of the workpiece to be processed both reaches the set threshold, then stop.

[0058] S2. Adjust the center of the ball and the intersection point of the A-axis rotary table and the B-axis rotary table to be concentric:

[0059] Place the probe of the contact displacement sensor on the surface of the workpiece to be machined, and read the indication of the contact displacement sensor at this time;

[0060] Overall translation: Overall, compared with the prior art, the above technical solutions conceived by the present invention have the following beneficial effects: Specific content translation: By adjusting the displacement adjustment unit of the workpiece five-axis adjustment frame, the overall front-back translation of the workpiece five-axis adjustment frame is carried out until the indication of the contact displacement sensor remains unchanged when the A-axis rotary table rotates 90 degrees;

[0061] S3. According to the pattern to be machined on the surface of the workpiece to be machined, calculate the angles that the A-axis rotary table and the B-axis rotary table need to rotate in the continuous working state, so as to etch the pattern to be machined on the spherical surface at high speed and with high precision.

[0062] Overall, compared with the prior art, the above technical solutions conceived by the present invention have the following beneficial effects:

[0063] (1) The present invention proposes a workpiece five-axis adjustment frame. By rotating the adjustment unit located on the five-axis adjustment frame, forces in different directions are applied to the positioning disk, thereby changing the pitch angle and spatial position of the workpiece fixed on the five-axis adjustment frame, realizing high-precision pose adjustment of the workpiece, and thus enabling the double-rotary table rotation axis, the workpiece curvature center, and the laser optical axis to achieve high-precision coincidence.

[0064] (2) The present invention proposes a five-axis motion device. Through the coordinated control of the A-axis rotary table and the B-axis rotary table, utilizing the rotation characteristics of the workpiece to be machined, a processing method with a fixed laser focus position and high-speed and high-precision rotation of the workpiece is adopted. During the processing process, it is not necessary to control the lifting of the Z-axis, and the focusing accuracy error caused by the change of the optical path scanning is eliminated. Since the five-axis adjustment frame can perform high-precision coaxial and concentric adjustment on the workpiece, a high-quality focusing effect can be maintained when the workpiece rotates.

[0065] (3) The present invention proposes a five-axis laser processing system. The laser is focused on a point in space in the horizontal direction through a laser beam expander, a fixed mirror, and a liftable mirror, and the liftable mirror and the laser focusing mirror are adjusted by adjusting the Z-axis linear displacement platform, thereby adjusting the focusing position of the laser in the Z-axis direction. Through the CCD camera located on the same Z-axis linear displacement platform as the laser focusing mirror, the spatial position coordinates of the laser focusing point are found, and these coordinates are the position coordinates that the surface of the workpiece to be machined needs to be adjusted to; through the contact displacement sensor located on the same Z-axis linear displacement platform as the laser focusing mirror, in cooperation with the workpiece five-axis adjustment frame proposed by the present invention, the coaxial and concentric accuracy of the workpiece is measured and adjusted, so as to achieve high-precision coincidence of the spatial focusing position and the surface of the workpiece to be machined.

[0066] (4) The present invention provides a machining method for a five-axis laser machining system. By adjusting the spatial pose of the workpiece to be machined through a five-axis adjustment frame, any curved surface workpiece with a rotation center can be adjusted to the machining position, so that one or more of its rotation axes are coaxial with one or more of the rotation axes of the A-axis rotary table and the B-axis rotary table. Thus, the A-axis rotary table and the B-axis rotary table drive the workpiece to perform spatial rotation, and the rotation angle and speed are determined by the machining pattern, realizing the machining of the set pattern on the workpiece surface with high precision and high speed. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] Figure 1 FIG. is a schematic diagram of a five-axis laser machining system provided by the present invention.

[0068] Figure 2 FIG. is a schematic diagram of the structure of the five-axis adjustment frame for the workpiece provided by the present invention.

[0069] Figure 3 FIG. is a schematic diagram of the operation of the five-axis adjustment frame for the workpiece provided by the present invention.

[0070] Figure 4 FIG. is a schematic diagram of the laser etching path on the workpiece surface provided by the present invention.

[0071] In all the drawings, the same reference numerals are used to represent the same elements or structures, where:

[0072] 1-1: Laser light source, 1-2: Laser beam expander, 1-3: Fixed mirror, 1-4: Liftable mirror, 1-5: Laser focusing mirror, 2-1: CCD camera, 2-2: Contact displacement sensor, 3: Five-axis adjustment frame for workpiece, 4-1: A-axis rotary table, 4-2: Rotary table connecting piece, 4-3: B-axis rotary table, 5-1: XY-axis two-dimensional linear displacement platform, 5-2: Z-axis linear displacement platform, 6: Related control system, 7: Workpiece to be machined, 3-1: Positioning disk, 3-2: Fixing piece, 3-3: Fastening screw, 3-4, 3-7, 3-10: Threaded holes, 3-6, 3-9, 3-12: First screws, 3-5, 3-8, 3-11: Second screws, 3-13: Upper layer part, 3-14: Lower layer part. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0073] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0074] Figure 1 FIG. is a schematic diagram of a five-axis laser machining system provided by the present invention. As Figure 1As shown in the figure, the processing system includes: a laser light source 1-1, a laser beam expander 1-2, a fixed mirror 1-3, a liftable mirror 1-4, a laser focusing lens 1-5, a CCD camera 2-1, a positioning sensor 2-2, a five-axis workpiece adjustment stand 3, an A-axis rotary table 4-1, a rotary table connecting piece 4-2, a B-axis rotary table 4-3, an XY-axis two-dimensional linear displacement platform 5-1, a Z-axis linear displacement platform 5-2, a related control system 6, and a workpiece to be processed 7.

[0075] The laser light source 1-1 is used to generate laser light. The laser beam expander 1-2 is used to obtain a smaller spot size. The fixed mirror 1-3 and the liftable mirror 1-4 are used to deflect and adjust the optical path. The laser focusing lens 1-5 is used to focus the spot on the surface of the workpiece to be processed 7. The spot is focused at a point in space. By the action of the laser on the conductive glass and with the assistance of the CCD camera and the positioning sensor, the three-dimensional position of the laser focus in space is obtained.

[0076] The CCD camera 2-1 is used to determine the accurate position of the focal plane in space and assist in workpiece positioning. The positioning sensor 2-2 is used to detect the positioning accuracy and coaxial accuracy before system processing.

[0077] The five-axis workpiece adjustment stand 3 is used to precisely adjust the spatial positional relationship between the workpiece to be processed 7, the B-axis rotary table 4-3, and the A-axis rotary table 4-1.

[0078] The B-axis rotary table 4-3 and the A-axis rotary table 4-1 are used to control the etching path of the workpiece to be processed 7.

[0079] The XY-axis two-dimensional linear displacement platform 5-1 is used to control the planar movement of the workpiece to be processed 7. The Z-axis linear displacement platform 5-2 is used to change the relative positions of the positioning sensor 2-2, the laser focusing lens 1-5, the CCD camera 2-1, and the workpiece to be processed 7.

[0080] The workpiece to be processed 7 is used for processing. The related control system 6 is used to control the laser light source 1-1, the positioning sensor 2-2, the Z-axis linear displacement platform 5-2, the CCD camera 2-1, the B-axis rotary table 4-3, the A-axis rotary table 4-1, and the XY-axis two-dimensional linear displacement platform 5-1 to work together.

[0081] Figure 2 It is a schematic structural diagram of the five-axis workpiece adjustment stand provided by the present invention. Among them, (a) is a top view, (b) is a side view, and (c) is an exploded view. As Figure 2As shown, the five-axis adjustment fixture 3 for the workpiece is of a double-layer structure. Its lower layer 3-14 can be fixed on the B-axis rotary table 4-3 through three threaded holes 3-4, 3-7, and 3-10 that penetrate the adjustment fixture. The upper layer 3-13 has a positioning disk 3-1 for installing the workpiece. There are fixing parts 3-2 and fastening screws 3-3 on the positioning disk 3-1, which can be used to fix various types of workpieces 7 to be machined. The upper and lower layers of the five-axis adjustment fixture 3 for the workpiece are closely connected and can rotate coaxially. Through the connection of the five-axis adjustment fixture 3 for the workpiece, the motion control of the B-axis rotary table 4-3 can be transmitted to the workpiece 7 to be machined immediately. There is an air layer between the upper and lower layers of the five-axis adjustment fixture 3 for the workpiece, leaving space for adjusting the relative positions of the upper and lower layers.

[0082] Furthermore, the upper layer 3-13 of the five-axis adjustment fixture 3 for the workpiece has six screws that can be used to adjust the displacement and angle of the workpiece. Among them, screws 3-5, 3-8, and 3-11 are located on the disk surface of the adjustment fixture and can be used to control the tilt angle of the workpiece; screws 3-6, 3-9, and 3-12 are located on the side cylindrical surface of the adjustment fixture and can be used to control the displacement of the workpiece. When the workpiece 7 to be machined is installed on the five-axis adjustment fixture 3 through the positioning disk 3-1, the pose of the workpiece 7 to be machined can be adjusted through the above-mentioned components, so as to achieve high-precision coaxiality between the rotation axes of the workpiece 7 to be machined in the A and B axis directions and the A-axis rotary table 4-1 and the B-axis rotary table 4-3 respectively.

[0083] Figure 3 This is a working schematic diagram of the five-axis adjustment fixture for the workpiece provided by the present invention. The present invention is applicable to rotatable workpieces. In this embodiment, a spherical shaft workpiece is taken as an example to further illustrate the working principle of the five-axis adjustment fixture 3. The spherical shaft of the workpiece to be machined is fixed on the B-axis rotary table through the five-axis adjustment fixture for the workpiece. If it is necessary to ensure that the laser optical axis is always perpendicular to the spherical surface and points to the center of the sphere during the rotation of the workpiece to be machined, two coaxial and concentric adjustments are required at this time: adjusting the axes of the spherical shaft and the B-axis rotary table to be coaxial, and adjusting the center of the sphere and the intersection point of the A-axis rotary table and the B-axis rotary table to be concentric.

[0084] As Figure 3 shown in (a)-(b) below, after the workpiece 7 to be machined is fixed on the B-axis rotary table 4-3 through the five-axis adjustment fixture 3, first use the positioning sensor 2-2 to measure the side surface of the B-axis rotary table 4-3, and ensure that the side surface of the B-axis rotary table 4-3 is perpendicular to the probe of the positioning sensor 2-2 by rotating the A-axis rotary table 4-1.

[0085] As Figure 3As shown in FIGS. (c)-(d), place the probe of the positioning sensor 2-2 at the root of the workpiece 7 to be machined, rotate the B-axis rotary table 4-3, read the readings, and adjust the displacement of the workpiece five-axis adjustment bracket 3 through the screws 3-6, screws 3-9, and screws 3-12 until the readings of the positioning sensor 2-2 remain unchanged when the B-axis rotary table 4-3 rotates, indicating that the workpiece axis intersects with the rotary table axis at the root of the workpiece.

[0086] As Figure 3 As shown in FIGS. (e)-(f), place the probe of the positioning sensor 2-2 on the spherical surface of the workpiece 7 to be machined, rotate the B-axis rotary table 4-3, read the readings, and adjust the tilt angle of the workpiece five-axis adjustment bracket 3 through the screws 3-5, screws 3-8, and screws 3-11 until the readings of the positioning sensor 2-2 remain unchanged when the B-axis rotary table 4-3 rotates, indicating that the workpiece axis intersects with the rotary table axis at the top of the workpiece, and at this time the workpiece axis and the rotary table axis are completely coincident.

[0087] In the actual adjustment process, the above adjustment of the root of the spherical axis and the adjustment of the upper part of the spherical axis will affect each other. By continuously repeating the above two steps, the error can be continuously reduced until the adjustment accuracy of both the root of the spherical axis and the upper part of the spherical axis reaches below 10 μm. At this time, it can be considered that the rotating shafts of the spherical axis and the B-axis rotary table have been adjusted to the coaxial state. Next, adjust the center of the sphere and the intersection point of the A-axis rotary table and the B-axis rotary table to be concentric.

[0088] As Figure 3 As shown in FIGS. (g)-(h), place the probe of the positioning sensor 2-2 on the spherical surface of the workpiece 7 to be machined, rotate the A-axis rotary table 4-1 by 90 degrees, read the readings of the positioning sensor 2-2 twice, and perform overall front-back translation of the workpiece five-axis adjustment bracket 3 through the screws 3-5, screws 3-8, and screws 3-11 until the readings of the positioning sensor 2-2 remain unchanged when the A-axis rotary table 4-1 rotates, indicating that the rotation axis of the A-axis coincides with the center of the sphere of the workpiece.

[0089] The above examples can simply illustrate the working principle of the workpiece five-axis adjustment bracket 3. In the actual machining process, its applicable objects include but are not limited to spherical axis workpieces, and also include workpieces with conical surfaces, cylindrical surfaces or other various curved surfaces with a rotation center on the surface to be machined. Any displacement, tilt angle, etc. adjustment of the workpiece 7 to be machined based on this invention is within the scope of protection of this invention.

[0090] Figure 4 It is a schematic diagram of the laser engraving path on the workpiece surface provided by the present invention. As Figure 4As shown, taking a spherical shaft workpiece as an example, the laser is focused on the surface of the workpiece 7 to be processed by the laser focusing lens 1-5. The workpiece 7 to be processed is controlled by the A-axis rotary table 4-1 and the B-axis rotary table 4-3, enabling the workpiece to rotate around the A-axis and the B-axis. The etching paths generated by the laser along the A-axis and the B-axis are curves. Through the coordinated movement of the two axes, a curved surface pattern is etched on the surface of the workpiece 7 to be processed by the laser.

[0091] The subsequent processing steps are as follows: The two-axis rotary table workpiece (A-axis rotary table and B-axis rotary table) rotating device and the workpiece are driven by the XY-axis two-dimensional linear displacement platform to move to the three-dimensional position of the recorded laser focus in space; the laser focusing system and the liftable mirror in front of it are fixed on the Z-axis linear displacement platform, and the optical path can be moved in the Z-axis direction before processing. During the processing, the laser optical path remains stationary, and its spatial focusing position has been aligned with the workpiece surface before processing. The workpiece to be processed is driven by the two-axis rotary table workpiece rotating device to move, so that a relative movement is generated between the workpiece to be processed and the laser focus, thereby obtaining the pattern etched by the laser curved surface path.

[0092] The laser etching process for the surface of the revolving curved surface workpiece is as follows: Using the beam expander and focusing lens group of the laser beam shaping and focusing device, the approximate position of the focused spot is obtained within a working distance of about 3 mm to 10 mm behind the focusing lens group, and the spot diameter is about 0.5 μm - 50 μm. After focusing, the pre-scanned spot is accurately measured by a CCD camera to determine and record the accurate position of the focus in space; the workpiece is fixed on the workpiece five-axis adjustment frame of the B-axis rotary table, and the coaxiality of the B-axis rotary table rotation axis, the workpiece curvature center, and the laser optical axis is measured by the positioning sensor of the coaxial positioning device, and the displacement and angle of the workpiece are adjusted by the screws of the workpiece five-axis adjustment frame. After adjustment, it is measured again by the positioning sensor, and this step is repeated until the positioning accuracy is adjusted to below 10 μm. After the adjustment is completed, the two-axis rotary table workpiece rotating device with the workpiece to be processed is moved by the XY-axis two-dimensional linear displacement platform, so that the workpiece surface is located at the recorded focus position; the movement path of the double rotary table is set according to the workpiece to be processed, so that when the workpiece moves, the laser beam etches the preset pattern on the surface of the workpiece to be processed on the curved surface workpiece.

[0093] Those skilled in the art can easily understand that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A laser etching processing method for the surface of a curved workpiece with a rotation center, characterized in that, The method includes: S1. Determine the three-dimensional position of the laser focus in space when the light spot is focused on the surface of the workpiece to be processed; S2. Fix the workpiece to be processed on the B-axis rotating table through the five-axis adjustment frame of the workpiece, and perform coaxial and concentric adjustment. The coaxial and concentric adjustment includes: adjusting the rotation axes of the workpiece to be processed and the B-axis rotating table to be coaxial, and adjusting the center of rotation of the workpiece to be processed and the intersection of the A-axis rotating table and the B-axis rotating table to be concentric. The five-axis adjustment frame of the workpiece is used to control the tilt angle and pose of the workpiece. Its lower layer is fixed to the B-axis rotating table to immediately transfer the motion control of the B-axis rotating table to the workpiece to be processed. The B-axis rotating table is used to drive the lower layer to rotate around the B-axis perpendicular to the vertical plane. The A-axis rotating table is used to drive the rotating table connecting member to rotate around the A-axis perpendicular to the horizontal plane, and the A-axis is parallel to the Z-axis direction; S3. Move the workpiece to be processed so that it is located at the three-dimensional position of the laser focus in space; S4. Set the motion paths of the A-axis rotating table and the B-axis rotating table through the to-be-processed graphics, thereby driving the workpiece to be processed to move, so that the workpiece to be processed and the laser focus generate relative motion, and the laser beam etches a preset graphic on the to-be-processed surface of the curved workpiece. During the processing, the position of the laser focus remains fixed.

2. The processing method according to claim 1, wherein The adjustment of aligning the rotation axes of the workpiece to be processed and the B-axis rotating table to be coaxial is specifically: Rotate the A-axis rotating table to ensure that the side surface of the rotating table connecting member is perpendicular to the probe of the contact displacement sensor; Place the probe of the contact displacement sensor at the root of the workpiece to be processed, rotate the B-axis rotating table, and read the indication of the contact displacement sensor at this time; Adjust the displacement of the workpiece to be processed until the indication of the contact displacement sensor remains unchanged when the B-axis rotating table rotates; Place the probe of the contact displacement sensor on the surface of the workpiece to be processed, rotate the B-axis rotating table, and read the indication of the contact displacement sensor at this time; Adjust the tilt angle of the workpiece to be processed until the indication of the contact displacement sensor remains unchanged when the B-axis rotating table rotates; Continuously repeat the above two adjustment steps until the adjustment accuracies of the root and surface of the workpiece to be processed both reach the set threshold, then stop.

3. The processing method according to claim 2, characterized in that, The adjustment of aligning the center of rotation of the workpiece to be processed and the intersection of the A-axis rotating table and the B-axis rotating table to be concentric is specifically: Place the probe of the contact displacement sensor on the surface of the workpiece to be processed, and read the indication of the contact displacement sensor at this time; Perform overall front-back translation of the workpiece to be processed until the indication of the contact displacement sensor remains unchanged when the A-axis rotating table rotates 90 degrees.

4. The processing method according to claim 1, characterized in that, Step S1 is specifically: Focus the laser horizontally on a point in space through a laser beam expander, a fixed mirror, and a liftable mirror, and adjust the liftable mirror and the laser focusing mirror by adjusting the Z-axis linear displacement platform, so as to adjust the focusing position of the laser in the Z-axis direction; Use a CCD camera located on the same Z-axis linear displacement platform as the laser focusing mirror to find the spatial position coordinates of the laser focusing point, and this coordinate is the position coordinate that the surface of the workpiece to be processed needs to be adjusted to.

5. A laser etching processing system for the surface of a curved workpiece with a rotation center, characterized in that, Includes: Five-axis motion device, laser light source, laser beam expander, fixed mirror, liftable mirror, laser focusing lens, CCD camera, contact displacement sensor, Z-axis linear displacement platform, and controller; The five-axis motion device includes: workpiece five-axis adjustment frame, A-axis rotary table, rotary table connecting piece, B-axis rotary table, XY-axis two-dimensional linear displacement platform; The workpiece five-axis adjustment frame is used to adjust the tilt angle and pose of the workpiece. Its lower layer is fixed to the B-axis rotary table to immediately transfer the motion control of the B-axis rotary table to the workpiece to be processed; The B-axis rotary table is used to drive the lower layer to rotate around the B-axis perpendicular to the vertical plane; The A-axis rotary table is used to drive the rotary table connecting piece to rotate around the A-axis perpendicular to the horizontal plane, and the A-axis is parallel to the Z-axis direction; The A-axis rotary table and the B-axis rotary table are orthogonally connected through the rotary table connecting piece, so that the rotation center lines of the two rotary tables coincide at a point in space; The A-axis rotary table is fixed on the XY-axis two-dimensional linear displacement platform; The XY-axis two-dimensional linear displacement platform is used to drive the A-axis rotary table to perform translation in space; The laser light source is used to generate laser light that enters the laser beam expander; The laser beam expander is used to obtain a smaller spot size; The fixed mirror and the liftable mirror are used to deflect and adjust the optical path; The laser focusing lens is used to focus the spot on the surface of the workpiece to be processed; The CCD camera is located on the same Z-axis linear displacement platform as the laser focusing lens and is used to find the spatial position of the laser focusing point; The contact displacement sensor is located on the same Z-axis linear displacement platform as the laser focusing lens and is used to measure the side surface of the rotary table connecting piece; The Z-axis linear displacement platform is used to drive the laser focusing lens fixed on the Z-axis linear displacement platform to perform up and down translation motion in space; The controller is used to control the CCD camera and the contact displacement sensor to perform positioning, so as to determine the three-dimensional position of the laser focus in space when the spot is focused on the surface of the workpiece to be processed, control the A-axis rotary table, the B-axis rotary table, the XY-axis two-dimensional linear displacement platform, and the Z-axis linear displacement platform to perform motion. After coaxial and concentric adjustment, move the workpiece to be processed so that it is located at the three-dimensional position of the laser focus in space. Set the motion path of the A-axis rotary table and the B-axis rotary table through the to-be-processed graphics, so as to drive the workpiece to be processed to move, make the workpiece to be processed and the laser focus generate relative motion, and the laser beam etches a preset graphic on the to-be-processed surface of the curved workpiece. During the processing, the position of the laser focus remains fixed, and control the adjustment of the laser parameters of the laser light source; The coaxial and concentric adjustment includes: adjusting the axis of the workpiece to be processed and the B-axis rotary table to be coaxial, and adjusting the center of rotation of the workpiece to be processed and the intersection point of the A-axis rotary table and the B-axis rotary table to be concentric.

6. The processing system according to claim 5, wherein, The workpiece five-axis adjustment frame includes: upper layer, lower layer, positioning disk, angle adjustment unit, displacement adjustment unit, and connection unit; There is a groove in the middle of the upper layer; The positioning disk is a frustum with a fixing part on the upper end surface, and the fixing part is used to fix the workpiece to be processed; The upper layer part and the lower layer part are elastically connected with a gap left in between, thereby forming an installation cavity; The positioning disc is arranged in the installation cavity, and its bottom surface is in contact with the groove surface; The angle adjustment unit penetrates through the upper layer part surface and abuts against the upper surface of the lower layer part, and is used for adjusting the pitching angle of the upper layer part in space; The displacement adjustment unit penetrates through the side surface of the upper layer part and abuts against the round platform of the positioning disc, and is used for adjusting the relative position of the positioning round platform in space; The connection unit penetrates through the lower layer part surface and is used for fixing the lower layer part and the B-axis rotary table.

7. The processing system according to claim 6, wherein Both the angle adjustment unit and the displacement adjustment unit are N screws, where N≥3.

8. The processing system according to claim 7, wherein The N screws are evenly distributed at equal intervals.

9. The processing system according to claim 5, characterized in that, The angle adjustment range of the workpiece five-axis adjustment frame is between 0° and 30°.

10. The processing system according to claim 5, wherein The displacement adjustment range of the workpiece five-axis adjustment frame is between 0.0001 mm and 10 mm.

11. The processing system according to claim 6, wherein The side surface of the fixing part of the positioning disc is provided with fastening screws.

12. The processing system according to claim 6, wherein Between the upper layer part and the lower layer part, elastic connection is achieved through a pin and a spring. Both ends of the spring pass through the through holes on the upper layer part and the lower layer part respectively. There are pin slots for placing pins at the through holes, and the pins are used to keep the spring in a certain compressed or extended state.

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