Laser heating and ultrasonic vibration assisted ultra-precision machining turning and milling integrated machine tool and control method
By designing an ultra-precision turning and milling integrated machine tool that integrates laser heating and ultrasonic vibration, the problems of installation error and multi-angle displacement transmission in the prior art are solved, and high-precision processing and longer machine tool life are achieved.
Patent Information
- Application Number
- CN202411441384.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-16
- Publication Date
- 2024-12-13
- Estimated Expiration
- 2044-10-16
AI Technical Summary
The existing ultra-precision machine tools have limitations in appearance and size when installing laser and ultrasonic devices, resulting in large installation errors and the prior art is difficult to achieve multi-angle displacement transmission and decomposition, resulting in low machining accuracy.
A turning and milling integrated machine tool integrating laser heating, ultrasonic vibration and ultra-precision processing is designed, using a self-leveling air-floating vibration isolation platform, a liquid static pressure guide rail and an iron-free permanent magnet synchronous linear motor, combined with multi-axis Flexible hinges and curved guides enable precise tool tip micro-moving track control and multi-angle preheating.
It significantly improves processing accuracy, reduces external vibration effects, reduces cutting force and subsurface damage, extends the service life of the machine tool, and achieves higher structural stiffness and thermal stability.
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Figure CN119115564A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the field of ultra-precision machining, and in particular relates to a five-axis linkage energy field composite assisted ultra-precision machining turning and milling integrated machine tool. Background Art
[0002] Laser heating-assisted processing technology and ultrasonic elliptical vibration-assisted processing technology are new processing technologies for difficult-to-process materials. Lasers are ideal heat sources for local heating due to their excellent directionality, monochromaticity, coherence, and high-power forming capabilities. However, lasers can cause burning during processing and produce micro-cracks on the processed surface. Vibration-assisted processing allows intermittent contact between the tool and the workpiece, which can significantly reduce cutting force and tool wear and improve workpiece surface quality. However, during processing, they are susceptible to alternating stress and chipping. Both methods have their own advantages and disadvantages, so coupling energy fields to process difficult-to-process materials has become a major research hotspot.
[0003] Existing ultra-precision machine tools have great limitations on the installation of laser devices and ultrasonic devices. There are restrictions on the shape and size of the devices, which may also cause large installation errors. Therefore, it is necessary to design an ultra-precision machining machine tool based on laser heating assistance and ultrasonic vibration assistance, and integrate the turning and milling devices on one machine tool. The laser device and ultrasonic device are taken into consideration at the beginning of the machine tool design to reduce installation errors. At the same time, the ultrasonic system and laser system are accurately controlled according to the corresponding control algorithm, and the machinability of difficult-to-process materials is improved with ultra-precision machining.
[0004] Patent No.: CN201710120586.9. In the design method of the three-dimensional elliptical vibration assisted cutting device, the flexible hinge branch is a straight rod, and the flexible hinge is a single axis, which only realizes the function of amplifying and transmitting displacement. The amplification ratio is insufficient and multi-angle displacement transmission, decomposition and synthesis cannot be realized.
[0005] Journal: Discussion on the displacement calculation method of curved bar structure in structural mechanics. The curved bar in the article is a curved bar with a constant cross-section. The displacement calculation method of the flexible hinge branch in the present invention is a displacement calculation method of a curved bar with a variable cross-section.
[0006] Patent number: CN202221755427.9, a five-axis horizontal machining center machine tool uses a screw drive, which is prone to greater friction and wear under high load conditions and has a shorter service life.
[0007] Patent number: CN202110075133.5. The laser ultrasonic composite turning processing device uses an external laser device. The laser isolator is inconvenient to adjust, and there is only an external device, and the laser focusing accuracy is insufficient. The ultrasonic device is single-excitation, and the vibration effect is not as good as the multi-excitation ultrasonic device. Summary of the invention
[0008] The present invention provides a machine tool which integrates laser heating, ultrasonic vibration and ultra-precision machining, and combines turning and milling. The purpose is to realize laser heating and ultrasonic vibration composite assisted ultra-precision machining, and at the same time, turning and milling are integrated into one, which can better improve the machinability of difficult-to-machine materials.
[0009] The purpose of the present invention is achieved through the following technical solutions, in conjunction with the accompanying drawings:
[0010] The laser-heated ultrasonic vibration-assisted ultra-precision machining turning-milling integrated machine tool is characterized in that it comprises a self-leveling air-floating vibration isolation platform 1, an X-axis translation module 2, a Y-axis translation module 3, a Z-axis translation module 4, a B-axis rotation module 5, a C-axis rotation module 6, a laser-heated ultrasonic vibration-assisted turning module 7, a laser-heated ultrasonic vibration milling auxiliary module 8, and a heat preservation cover module 9; the X-axis translation module 2 and the Z-axis translation module 4 are both placed on the self-leveling air-floating vibration isolation platform 1, and the The Y-axis translation module 3 is fixed to the X-axis translation module 2 by screw connection, the C-axis rotation module 6 is fixed to the Y-axis translation module 3 by screw connection, the B-axis rotation module 5 is fixed to the Z-axis translation module 4 by screw connection, the laser heating ultrasonic vibration assisted turning module 7 and the laser heating ultrasonic vibration milling module 8 are both fixed to the B-axis rotation module 5 by screw connection, and the thermal insulation cover module 9 is fixed to the self-leveling air-floating vibration isolation platform 1 by screw connection.
[0011] Furthermore, the self-leveling air-floating vibration isolation platform 1 includes a marble base 101, an L-shaped support frame 102, a self-leveling air-floating vibration isolator 103, an I-shaped support frame 104, and an adjustment anchor bolt 105; four adjustment anchor bolts 105 are fixed to the bottom of the I-shaped support frame 104 by screw connection; four self-leveling air-floating vibration isolators 103 are fixed to the top of the I-shaped support frame 104 by screw connection; four L-shaped support frames 102 are fixed to the self-leveling air-floating vibration isolators 103 by screw connection; and the marble base 101 is placed on the L-shaped support frame 102.
[0012] Furthermore, the X-axis translation module 2 includes a guide member 201, a guide rail 202, a stator 203 of a coreless permanent magnet synchronous linear motor, a mover 204 of a coreless permanent magnet synchronous linear motor, a slide 205, a grating scale 206, a grating scale reading head 207, an L-shaped support frame 208, a limit switch 209, an oil return tank 210, an accordion cover 211, and a Z-shaped baffle 212; the guide member 201 is fixed to the oil return tank 210 by screw connection; the stator 203 of the coreless permanent magnet synchronous linear motor is fixed to the middle part of the guide member 201 by screw connection; and two guide rails 202 are fixed to the guide member 201 by screw connection; The slide 205 is installed on the guide rail 202; the coreless permanent magnet synchronous linear motor mover 204 is fixed to the middle of the slide 205 by screw connection; the grating scale fixed length 206 is fixed to one side of the guide member 201 by screw connection; the grating scale reading head 207 is fixed to the L-shaped support frame 208 by screw connection; the L-shaped support frame 208 is fixed to one side of the slide 205 by screw connection; the limit switch 209 is fixed to one side of the guide member 201 by screw connection; the Z-shaped baffle 212 is fixed to one side of the slide 205 by screw connection; the two ends of the accordion cover 211 are respectively fixed to the return oil tank 210 and the slide 205 by screw connection.
[0013] Furthermore, the Y-axis translation module 3 includes a gravity-balanced frictionless cylinder 301, an upper end cover 302, a thrust plate 303, a side plate 304, an anti-collision plate 305, a second stator 306 of a coreless permanent magnet synchronous linear motor, a second mover 307 of a coreless permanent magnet synchronous linear motor, a second grating scale fixed scale 308, a second grating scale reading head 309, a second slide 310, a lower end cover 311, and a rear end cover 312; the internal connecting rod of the gravity-balanced frictionless cylinder 301 is fixed to the top of the second slide 310 by screw connection, and the cylinder barrel is fixed to the top of the upper end cover by screw connection; the mover of the coreless permanent magnet synchronous linear motor The second sub-head 307 is fixed to the left side of the second slide 310 by screw connection; the grating scale reading head 309 is fixed to the right side of the second slide 310 by screw connection; the thrust plate 303 is fixed to both sides of the upper end cover 302 and the lower end cover 311 by screw connection; the coreless permanent magnet synchronous linear motor stator 306 is fixed to the left thrust plate 303 by screw connection; the grating scale fixed length 308 is fixed to the right thrust plate 303 by screw connection; the side plate 304 is fixed to both sides of the thrust plate 303 by screw connection; the rear end cover 312 is fixed to the back of the upper end cover 302 and the lower end cover 311 by screw connection.
[0014] Furthermore, the Z-axis translation module 4 includes a second guide member 401, a second guide rail 402, a third iron-core permanent magnet synchronous linear motor stator 403, a third iron-core permanent magnet synchronous linear motor mover 404, a third slide plate 405, a third grating scale fixed scale 406, a third grating scale reading head 407, a second L-shaped support frame 408, a second limit switch 409, a second oil return tank 410, a second accordion cover 411, and a second Z-shaped baffle 412; the second guide member 401 is fixed in the second oil return tank 410 by screw connection; the third iron-core permanent magnet synchronous linear motor stator 403 is fixed to the middle part of the second guide member 401 by screw connection; the two second guide rails 402 are fixed to the second guide member 401 by screw connection; Slide three 405 is installed on guide rail two 402; coreless permanent magnet synchronous linear motor mover three 404 is fixed to the middle of slide three 405 by screw connection; grating scale fixed length three 406 is fixed to one side of supporting member two 401 by screw connection; grating scale reading head three 407 is fixed to L-shaped support frame two 408 by screw connection; L-shaped support frame two 408 is fixed to one side of slide three 405 by screw connection; limit switch two 409 is fixed to one side of supporting member two 401 by screw connection; Z-shaped baffle two 412 is fixed to one side of slide three 405 by screw connection; both ends of accordion cover two 411 are respectively fixed to return oil tank two 410 and slide three 405 by screw connection.
[0015] Furthermore, the B-axis rotation module 5 includes an upper thrust plate 501, an oil retaining ring 502, a thrust bearing 503, a radial bearing 504, a rotating shaft 505, a lower thrust plate 506, a sleeve 507, a torque motor mover 508, a torque motor stator 509, a torque motor stator bracket 510, a turntable base 511, a rotating shaft connecting member 512, a circular grating reading head 513, and a circular grating fixed scale 514; the rotating shaft connecting member 512 is fixed to the middle of the turntable base 511 by a key connection; the circular grating reading head 513 is fixed to the rotating shaft connecting member 512 by a screw connection; the circular grating fixed scale 514 is fixed to the turntable base 511 by a key connection; the rotating shaft 50 5 is fixed to the rotating shaft connecting member 512 by key connection; the sleeve 507 is fixed to the rotating shaft 505 by key connection; the torque motor mover 508 is fixed to the sleeve 507 by screw connection; the torque motor stator 509 is fixed to the torque motor stator bracket 510 by screw connection; the torque motor stator bracket 510 is fixed to the turntable base 511 by screw connection; the lower thrust plate 506 is fixed to the turntable base 511 by screw connection; the upper thrust plate 501 is fixed to the rotating shaft 505 by key connection; the thrust bearing 503 is fixed to the turntable base 511 by screw connection; the radial bearing 504 is installed between the thrust bearing 503 and the rotating shaft 505.
[0016] Furthermore, the laser heating ultrasonic vibration assisted turning module 7 includes a hexagonal bracket 701, a base plate 702, a parabolic flexible hinge 703, a Langevin vibrator 704, a laser isolator 705, and a three-axis precision translation stage 706; the hexagonal bracket 701 is fixed to the base plate 702 by screw connection; the Langevin vibrator is fixed in the hexagonal bracket 701 by screw connection; the parabolic flexible hinge 703 is fixed to the Langevin vibrator 704 by bolt connection; the three-axis precision translation stage 706 is fixed to the inside of the hexagonal bracket 701 by screw connection; the laser isolator 705 is fixed to the three-axis precision translation stage 706 by screw connection.
[0017] Furthermore, the laser heating ultrasonic vibration assisted milling module 8 includes a bottom plate 801, an ultrasonic vibrator bracket 802, an ultrasonic vibrator 803, a milling cutter bracket 804, a column 805, a motor 806, an arc rotating shaft 807, an arc guide rail 808, a slide plate 809, a laser isolator 810, and a motor 811; the ultrasonic vibrator bracket 802 is fixed to the bottom plate 801 by screw connection; the milling cutter bracket 804 is fixed to the bottom plate 801 by screw connection; the column 8 05 is fixed to the marble base 101 by screw connection; motor 1 806 is fixed to the left column 805 by screw connection; one end of the arc-shaped rotating shaft 807 is connected to motor 1 806, and the other end is connected to the right column 805; the arc-shaped guide rail 808 is fixed to the arc-shaped rotating shaft 807 by screw connection; motor 2 811 is fixed to slide 4 809 by screw connection; slide 4 809 is installed on the arc-shaped guide rail 808; laser isolator 2 810 is fixed to slide 4 809 by screw connection.
[0018] The present invention also provides a control method for a laser-heated ultrasonic vibration-assisted ultra-precision turning-milling integrated machine tool, wherein the processing control process mainly includes the following steps:
[0019] Step 1: Use precision measuring instruments to measure the rough or semi-finished parts to be processed, obtain the workpiece point cloud data and initial parameters, and obtain the measurement model through surface reconstruction;
[0020] Step 2: By matching and comparing the machining allowance values between the measured model and the design model, the geometric information of the design model is analyzed, the machining process is simulated according to the initial parameters and machining allowance, and the appropriate machining parameters such as cutting depth, feed speed, and spindle speed are determined;
[0021] Step 3: According to the processing parameters, select appropriate ultrasonic system input parameters, and determine the tool tip micro-motion trajectory according to the geometric relationship and displacement transmission relationship of each part;
[0022] Step 4: According to the processing parameters, solve the processing trajectory of the tool, and then generate the corresponding NC processing code of the trajectory, which contains the data information of each axis;
[0023] Step 5: According to the processing parameters, the moving trajectory of the external laser system of the laser heating ultrasonic vibration assisted milling module is solved, and then the corresponding numerical control code is generated;
[0024] Step 6: Input the machining trajectory NC code into the NC machining machine to perform NC machining of the workpiece;
[0025] Step 7: Use precision measuring instruments to measure the various parameters of the processed semi-finished product or finished product and the surface of the workpiece;
[0026] Step 8: If the parameters of the measured model are within the required accuracy range, the processing is completed;
[0027] Step 9: If the parameters of the measurement model exceed the range required by the workpiece accuracy, return to step 1 to continue measuring and processing the parts and enter the next processing cycle.
[0028] The method for generating the tool tip micro-motion trajectory of a laser-heated ultrasonic vibration-assisted ultra-precision turning-milling integrated machine tool is characterized in that the tool tip micro-motion trajectory can be divided into the tool tip micro-motion trajectory of the laser-heated ultrasonic vibration-assisted turning module and the tool tip micro-motion trajectory of the laser-heated ultrasonic vibration-assisted milling module.
[0029] The laser heating ultrasonic vibration assisted turning module is an in-situ laser heating system, which has no effect on the micro-motion trajectory of the tool. Therefore, the micro-motion trajectory of the tool is provided by three ultrasonic vibrators. Assuming that the initial coordinates of the tool tip are (0,0,0), the coordinates of the tool tip after the movement are (x dt ,y dt ,z dt ), the tool micro-motion trajectory is further solved based on the decomposition of the tool motion. This solution process includes the following:
[0030] (1) With the initial point of the tool tip as the coordinate origin, a rectangular coordinate system is established. The direction from O0 to P0 is the Z-axis direction, and the direction from O0 to A0 is the X-axis direction. The Y-axis direction is determined according to the Cartesian left-hand coordinate system, and the tool coordinate system is established.
[0031] (2) The micro-motion of the tool tip is provided by three ultrasonic vibrators. Let f be the frequency, t be the time, A7, A8, A9 be the amplitude of the input displacement of the piezoelectric ceramic drive signal, θ1, θ2, θ3 be the initial phase and have a phase difference, and the piezoelectric ceramic drive signal can be obtained as: The three ultrasonic vibrators are provided with driving displacements z7, z8, and z9 by piezoelectric ceramic sheets, and the driving displacements can be amplified through the amplitude rod. The present invention uses an amplitude rod to amplify the driving displacements z7, z8, and z9 of the piezoelectric ceramic sheets by 2 times, so the input displacements z4=2z7, z5=2z8, and z6=2z9 provided by the ultrasonic vibrator to the flexible hinge branch can be obtained. The three ultrasonic vibrators have a certain phase difference respectively, so z4, z5, and z6 are different, and it can be assumed that z4≤z5≤z6.
[0032] (3) The flexible hinge branch is a parabolic rod with a rectangular variable cross-section. Taking the flexible hinge branch at the location of ultrasonic vibrator 1 as an example, a local coordinate system is established. Ultrasonic vibrator 1 provides a displacement of z4 and a force of F1 = F[z4(t)]; denote the bending moment, shear force, and axial force under unit load, respectively, and ER c S, GA, EA represent the bending, shear and tensile stiffness of the branch section respectively; A is the cross-sectional area of the branch, and A = ∫a p 2 cos(arctan(F'(x p )))dx p ; a p is the width of the branch chain; F'(x p ) is the slope equation of any point on the parabola; x p is the horizontal coordinate of each point of the branch in the local coordinate system; k is a coefficient related to the cross-sectional shape; α is the linear expansion coefficient of the material; h is the height of the branch cross section, and h = ∫a p cos(arctan(F'(x p )))dx p ; M, F s 、F N are bending moment, shear force, and axial force respectively; t0 is the temperature change at the rod axis; Δt is the difference in temperature change between the upper and lower edges of the section; R c Axis curvature radius; micro-segment axis length ds; S = Ay p is the area moment of the curved rod section about the neutral axis, y p is the distance between the centroid and the neutral axis of the cross section.
[0033] According to the principle of virtual work, the unit load method can be used to calculate the displacement of the parabolic rod with variable cross-section under the combined effect of load, temperature change and other factors:
[0034]
[0035] According to the formula, the output displacement z1 of the flexible hinge branch can be obtained, and z2 and z3 can be obtained similarly.
[0036] (4) Since a multi-axis flexible hinge is used, each flexible hinge has three rotational degrees of freedom. After the parabolic rod displacements z1, z2, and z3 are transmitted through the flexible hinge, they can be decomposed into three displacements. For example, if the angle between the displacement z1 and the XOY plane is α1, and the angle between the displacement z1 and the YOZ plane is β1, then the displacement transmission expression of the flexible hinge is: The same can be said The displacement in the X and Y directions only changes the horizontal position of the tool tip, so they can be directly added together to obtain the tool tip micro-motion trajectory:
[0037] (5) The displacement in the Z direction will cause the tool tip to tilt. The three sub-displacements z 11 、z 21 、z 31 They cannot be added directly, so the displacement synthesis process is decomposed into three parts, and the input displacement z is 11 、z 21 、z 31 Input to the flexible hinge branch, such as Fig.12 As shown. In which, the distance from the origin of the flexible hinge tool holder to the initial point of the tool tip is set to l1, and the distance from the coordinate origin to one of the ultrasonic vibrators is l2. According to the geometric relationship of the three sub-processes, the second micro-motion trajectory of the tool tip can be obtained as:
[0038]
[0039] (6) Combining tool tip micro-motion trajectory 1 and tool tip micro-motion trajectory 2, the tool tip micro-motion trajectory equation can be obtained as:
[0040] The laser heating ultrasonic vibration assisted milling module is a single excitation ultrasonic vibrator, so the tool micro-motion trajectory is relatively simple. The voltage signal is input to the piezoelectric ceramic sheet, and the piezoelectric ceramic sheet outputs a corresponding driving signal to make the ultrasonic vibrator change the corresponding position s along the axial direction. The function of the position change s with the change of the control voltage is s = F [A (u), f (u), θ (u), u], where A (u) is the amplitude of the ultrasonic vibrator vibration, f (u) is the frequency of the ultrasonic vibrator vibration, θ (u) is the phase difference of the ultrasonic vibrator vibration, and u = U (t). Substituting u = U (t) into s = F [A (u), f (u), θ (u), u] can obtain the position change of the tool tip. Since there is only one ultrasonic vibrator input, it is also the tool tip micro-motion equation of the laser heating ultrasonic vibration assisted milling module.
[0041] The laser heating ultrasonic vibration assisted milling module is an external laser group. In order to achieve follow-up heating of the workpiece, the external laser group needs to be controlled. The milling cutter tip is taken as the coordinate origin, the horizontal direction is the X-axis, and the vertical upward direction is the Z-axis. The coordinate axis is established according to the Cartesian left-hand coordinate system to determine the Y-axis direction. Assume that the radius of the arc guide is R, and the plane where the arc guide is located is parallel to the x-axis. m o m z m The plane angle is γ = γ(t), and the laser isolator is located at any position and x m o m y m The angle is δ=δ(t), and the column height is h1. Therefore, the geometric relationship shows that the motion equation of the laser isolator 1 in the tool coordinate system is:
[0042]
[0043] Laser isolator 2 is symmetrical to laser isolator 1 about the YOZ plane, so the motion equation of laser isolator 2 is:
[0044]
[0045] Take the center point of the C axis as the coordinate origin, the vertical axis upward direction as the Y axis, the X axis along the X axis translation module direction as the X axis, and establish the coordinate axis according to the Cartesian left-hand coordinate system to determine the Z axis direction, and then establish the machine tool coordinate system. The distance between the origin of the tool coordinate system and the origin of the machine tool coordinate system along the Z axis of the tool coordinate system is av f t, vertical distance along the X axis is bv y t, the distance along the Y axis is cv x t,v f is the tool feed speed, v y is the moving speed of the Y axis of the machine tool, v x is the moving speed of the X axis of the machine tool. When the origin of the tool coordinate system coincides with the origin of the machine coordinate system, the tool coordinate system first rotates 180° around its X axis, and then rotates 90° counterclockwise around its Z axis to coincide with the machine coordinate system. At the same time, the machine coordinate system: tool coordinate system = i:1, so the tool coordinate system can be converted to the machine coordinate system by magnifying the tool coordinate system i times. The tool coordinate system can be converted to the machine coordinate system through the conversion matrix T (cv x t,bv y t,-a+v f t) is converted to the machine tool coordinate system, and the conversion matrix can be expressed as:
[0046]
[0047] In addition to the transformation matrix, the coordinate system transformation relationship can be obtained by inferring the position coordinate relationship of any point from the tool coordinate system to the machine tool coordinate system. Assume that the position coordinate of any point in the tool coordinate system is (x d ,y d ,z d ), after the origin of the tool coordinate system coincides with the origin of the machine tool coordinate system, the position coordinates of any point are (x j1 ,y j1 ,z j1 ), so we can get The coordinates of any point after rotation transformation are (x j2 ,y j2 ,z j2 ), so we can get z j By magnifying it i times, we can get the conversion relationship between the tool coordinate system and the machine tool coordinate system.
[0048] The turning coordinate system and the milling coordinate system are both tool coordinate systems. The horizontal distance between the origin of the turning coordinate system and the center point of the rotating B axis is l1, and the horizontal distance between the origin of the milling coordinate system and the center point of the rotating B axis is l2. The vertical distance between the turning coordinate system and the milling coordinate system is h2, and the angle difference on the horizontal plane is 90°. The turning coordinate system can be converted to the milling coordinate system through the transformation matrix T1 (l1, l2, -h2). The transformation matrix can be expressed as:
[0049]
[0050] Therefore, the conversion between the turning coordinate system and the milling coordinate system can be expressed as:
[0051] The present invention has the following beneficial effects:
[0052] (1) The use of a self-leveling air-floating vibration isolation platform can make the machine tool have high structural rigidity, high vibration attenuation and good thermal stability, minimize the impact of external vibration on the machine tool, improve the machining accuracy of the machine tool, and achieve ultra-precision machining;
[0053] (2) The X-axis and Z-axis are designed as liquid hydrostatic guides, which have the advantages of high rigidity, good damping performance, low friction coefficient and no wear. During movement, the guide rails are separated from the slide by lubricating oil, which can balance the load, improve the guide rail accuracy, rigidity, bearing capacity, life, etc., and achieve ultra-precision machining;
[0054] (3) The B-axis is designed as a liquid hydrostatic turntable. It uses the liquid hydrostatic support principle and hydrostatic bearing technology to form a high-pressure oil film in the working state to separate the stator and rotor of the turntable and equalize the error, avoiding wear caused by direct contact between the two, thereby reducing the friction resistance of the turntable, eliminating the low-speed creep phenomenon, improving the load-bearing capacity and rigidity, and improving the turntable's rotation accuracy and rotation stability;
[0055] (4) The Y-axis is designed as a vertical axis and is equipped with a gravity-balanced frictionless cylinder, which can balance the gravity of the slide when the Y-axis is working, improve stability and machining accuracy, and effectively prevent the slide from falling rapidly due to loss of drive and causing damage when the Y-axis stops moving;
[0056] (5) The drive systems of the X, Y, Z translation axes and the B axis use coreless permanent magnet linear motors and frameless DC torque motors respectively. The coreless permanent magnet linear motor can avoid eddy current loss, cogging effect and reduce magnetic attraction, reduce heat generation, and achieve smoother movement and precise speed and position control; the frameless DC torque motor does not require gear transmission, has a compact structure, avoids transmission error interference in the intermediate links, and significantly improves the rigidity and response time of the system;
[0057] (6) The X, Y, Z translation axis and B axis position feedback systems use Renishaw linear grating and circular grating respectively. The grating is equipped with Hall elements to accurately generate current and has the characteristics of high speed, low moment of inertia, high precision, non-contact optical performance and zero backlash, which can accurately feedback position and speed signals;
[0058] (7) The laser heating ultrasonic vibration assisted turning system is designed as an in-situ laser heating-three-dimensional ultrasonic vibration assisted processing device, which can significantly reduce the impact of adverse thermal effects, reduce cutting forces and sub-surface damage; the tool holder and the flexible hinge are designed as an integrated type to avoid vibration interference caused by screw connections; at the same time, a three-axis precision translation stage is designed for fine-tuning of the laser isolator to improve processing accuracy;
[0059] (8) Using an external laser in conjunction with a milling module for processing, and using an arc guide to control the direction of the laser isolator, the workpiece can be preheated in all directions and at multiple angles, so that the workpiece is heated evenly and the processing accuracy of the workpiece is improved;
[0060] (9) Through laser heating and ultrasonic vibration-assisted ultra-precision machining of the tool tip micro-motion trajectory of the turning and milling machine tool, the electrical signal can be converted into a mechanical signal of the tool tip micro-motion, thus achieving precise control of ultrasonic vibration;
[0061] (10) The control method of the external laser group in the milling module of the integrated turning and milling machine tool using laser heating and ultrasonic vibration-assisted ultra-precision machining enables the laser to accurately hit the tip of the milling cutter, thereby softening the workpiece and improving the machining accuracy;
[0062] (11) The compilation of CNC code is achieved through the conversion between the machine tool coordinate system and the tool coordinate system, and the conversion between the turning coordinate system and the milling coordinate system in the tool coordinate system. BRIEF DESCRIPTION OF THE DRAWINGS
[0063] Figure 1It is a schematic diagram of the overall structure of the laser-heated ultrasonic vibration-assisted ultra-precision turning-milling integrated machine tool of the present invention;
[0064] Figure 2 It is a schematic diagram of the overall structure of the machine tool with the insulation cover module removed;
[0065] Figure 3 It is a structural schematic diagram of a self-leveling air-floating vibration isolation table;
[0066] Figure 4 It is a schematic diagram of the X-axis translation module structure;
[0067] Figure 5 It is a schematic diagram of the Y-axis translation module structure;
[0068] Figure 6 This is a schematic diagram of the Z-axis translation module structure;
[0069] Figure 7 It is a schematic diagram of the structure of the B-axis rotation module;
[0070] Figure 8 It is a schematic diagram of the structure of the laser heating ultrasonic vibration assisted turning module;
[0071] Fig. 9 It is a schematic diagram of the structure of the laser heating ultrasonic vibration assisted milling module;
[0072] Fig.10 It is a simplified diagram of a parabolic flexible hinge;
[0073] Fig.11 It is a simplified diagram of the forces acting on the flexible hinge;
[0074] Fig.12 This is a simplified diagram of the micro-motion breakdown of the turning module tool;
[0075] Fig.13 It is a simplified diagram of the location of the external laser;
[0076] Fig.14 It is a simplified diagram of coordinate conversion between machine tool coordinate system and tool coordinate system;
[0077] Fig.15 It is a simplified diagram of coordinate transformation between turning coordinate system and milling coordinate system;
[0078] Fig.16 It is the machine tool control flow chart;
[0079] Fig.17 It is the flow chart of solving tool tip micro-motion trajectory.
[0080] Among them: self-leveling air-floating vibration isolation platform 1, X-axis translation module 2, Y-axis translation module 3, Z-axis translation module 4, B-axis rotation module 5, C-axis rotation module 6, laser heating ultrasonic vibration assisted turning module 7, laser heating ultrasonic vibration assisted milling module 8, insulation cover module 9, marble base 101, L-shaped support frame 102, self-leveling air-floating vibration isolator 103, I-shaped support frame 104, adjustment anchor bolt 105, bearing guide 201, guide rail 202, coreless permanent magnet synchronous linear motor stator 203, coreless permanent magnet synchronous linear motor mover 20 4. Slide plate 205, grating ruler fixed length 206, grating ruler reading head 207, L-shaped support frame 208, limit switch 209, oil return tank 210, accordion cover 211, Z-shaped baffle 212, gravity balance frictionless cylinder 301, upper end cover 302, thrust plate 303, side plate 304, anti-collision plate 305, coreless permanent magnet synchronous linear motor stator 2 306, coreless permanent magnet synchronous linear motor mover 2 307, grating ruler fixed length 2 308, grating ruler reading head 2 309, slide plate 2 310, lower end cover 311, rear end cover 312, bearing guide Part 2 401, guide rail 2 402, ironless permanent magnet synchronous linear motor stator 3 403, ironless permanent magnet synchronous linear motor mover 3 404, slide 3 405, grating ruler fixed length 3 406, grating ruler reading head 3 407, L-shaped support frame 2 408, limit switch 2 409, oil return tank 2 410, accordion cover 2 411, Z-shaped baffle 2 412, upper thrust plate 501, oil retaining ring 1 502, thrust bearing 503, radial bearing 504, rotating shaft 505, lower thrust plate 506, shaft sleeve 507, torque motor mover 508, torque motor stator 509, Torque motor stator bracket 510, turntable base 511, shaft connector 512, circular grating reading head 513, circular grating fixed scale 514, hexagonal bracket 701, base plate 1 702, parabolic flexible hinge 703, Langevin vibrator 704, laser isolator 1 705, three-axis precision translation stage 706, base plate 2 801, ultrasonic vibrator bracket 802, ultrasonic vibrator 803, milling cutter bracket 804, column 805, motor 1 806, arc rotating shaft 807, arc guide rail 808, slide 4 809, laser isolator 2 810, motor 2 811. DETAILED DESCRIPTION
[0081] The specific implementation of the present invention is further described below with reference to the accompanying drawings.
[0082] like Figure 1 , Figure 2As shown, a five-axis linkage energy field composite assisted ultra-precision machining turning and milling integrated machine tool is characterized in that it includes a self-leveling air-floating vibration isolation platform 1, an X-axis translation module 2, a Y-axis translation module 3, a Z-axis translation module 4, a B-axis rotation module 5, a C-axis rotation module 6, a laser heating ultrasonic vibration assisted turning module 7, a laser heating ultrasonic vibration milling module 8, and a heat preservation cover module 9; the X-axis translation module 2 and the Z-axis translation module 4 are both placed on the self-leveling air-floating vibration isolation platform 1, and the The Y-axis translation module 3 is fixed to the X-axis translation module 2 by screw connection, the C-axis rotation module 6 is fixed to the Y-axis translation module 3 by screw connection, the B-axis rotation module 5 is fixed to the Z-axis translation module 4 by screw connection, the laser heating ultrasonic vibration assisted turning module 7 and the laser heating ultrasonic vibration milling module 8 are both fixed to the B-axis rotation module 5 by screw connection, and the thermal insulation cover module 9 is fixed to the self-leveling air-floating vibration isolation platform 1 by screw connection.
[0083] like Figure 3 As shown, the self-leveling air-floating vibration isolation platform 1 includes a marble base 101, an L-shaped support frame 102, a self-leveling air-floating vibration isolator 103, an I-shaped support frame 104, and an adjustment anchor bolt 105; four adjustment anchor bolts 105 are fixed to the bottom of the I-shaped support frame 104 by screw connection; four self-leveling air-floating vibration isolators 103 are fixed to the top of the I-shaped support frame 104 by screw connection; four L-shaped support frames 102 are fixed to the self-leveling air-floating vibration isolators 103 by screw connection; and the marble base 101 is placed on the L-shaped support frame 102. Its beneficial effect is to provide the main support for the machine tool, minimize the impact of external vibration on the machine tool, and improve the machining accuracy of the machine tool.
[0084] like Figure 4As shown, the X-axis translation module 2 includes a bearing member 201, a guide rail 202, a stator 203 of a coreless permanent magnet synchronous linear motor, a mover 204 of an ironless permanent magnet synchronous linear motor, a slide 205, a grating scale 206, a grating scale reading head 207, an L-shaped support frame 208, a limit switch 209, an oil return tank 210, an accordion cover 211, and a Z-shaped baffle 212; the bearing member 201 is fixed in the oil return tank 210 by screw connection; the stator 203 of the ironless permanent magnet synchronous linear motor is fixed to the middle part of the bearing member 201 by screw connection; two guide rails 202 are fixed to the bearing member 201 by screw connection; the slide Plate 205 is installed on guide rail 202; coreless permanent magnet synchronous linear motor mover 204 is fixed to the middle of slide 205 by screw connection; grating scale fixed length 206 is fixed to one side of supporting member 201 by screw connection; grating scale reading head 207 is fixed to L-shaped support frame 208 by screw connection; L-shaped support frame 208 is fixed to one side of slide 205 by screw connection; limit switch 209 is fixed to one side of supporting member 201 by screw connection; Z-shaped baffle 212 is fixed to one side of slide 205 by screw connection; both ends of accordion cover 211 are respectively fixed to return oil tank 210 and slide 205 by screw connection. The beneficial effect is that the coreless permanent magnet synchronous linear motor mover 204 drives the slide 205 to move linearly along the coreless permanent magnet synchronous linear motor stator 203, and the grating scale reading head 207 feeds back the position and speed information of the slide 205 to complete the translation in the X-axis direction.
[0085] like Figure 5As shown, the Y-axis translation module 3 includes a gravity-balanced frictionless cylinder 301, an upper end cover 302, a thrust plate 303, a side plate 304, an anti-collision plate 305, a second stator 306 of a coreless permanent magnet synchronous linear motor, a second mover 307 of a coreless permanent magnet synchronous linear motor, a second grating scale fixed scale 308, a second grating scale reading head 309, a second slide 310, a lower end cover 311, and a rear end cover 312; the internal connecting rod of the gravity-balanced frictionless cylinder 301 is fixed to the top of the second slide 310 by screw connection, and the cylinder barrel is fixed to the top of the upper end cover by screw connection; the mover of the coreless permanent magnet synchronous linear motor The second 307 is fixed to the left side of the second slide 310 by screw connection; the grating scale reading head 309 is fixed to the right side of the second slide 310 by screw connection; the thrust plate 303 is fixed to both sides of the upper end cover 302 and the lower end cover 311 by screw connection; the coreless permanent magnet synchronous linear motor stator 306 is fixed to the left thrust plate 303 by screw connection; the grating scale fixed size 308 is fixed to the right thrust plate 303 by screw connection; the side plate 304 is fixed to both sides of the thrust plate 303 by screw connection; the rear end cover 312 is fixed to the back of the upper end cover 302 and the lower end cover 311 by screw connection. The beneficial effect is that the coreless permanent magnet synchronous linear motor mover 2 307 drives the slide 2 310 to perform linear motion along the coreless permanent magnet synchronous linear motor stator 2 306, the grating scale reading head 2 309 feeds back the position and speed information of the slide 2 310, and the gravity-balancing frictionless cylinder 301 balances the gravity of the slide 2 310 to realize the translational motion in the Y-axis direction of the machine tool.
[0086] like Figure 6As shown, the Z-axis translation module 4 includes a second guide member 401, a second guide rail 402, a third iron-core permanent magnet synchronous linear motor stator 403, a third iron-core permanent magnet synchronous linear motor mover 404, a third slide plate 405, a grating scale fixed length 406, a third grating scale reading head 407, a second L-shaped support frame 408, a second limit switch 409, a second oil return tank 410, a second accordion cover 411, and a second Z-shaped baffle plate 412; the second guide member 401 is fixed in the second oil return tank 410 by screw connection; the third iron-core permanent magnet synchronous linear motor stator 403 is fixed to the middle part of the second guide member 401 by screw connection; the two guide rails 402 are fixed to the second guide member 401 by screw connection; the slide plate 405 is fixed to the second guide member 401 by screw connection; Plate three 405 is installed on guide rail two 402; coreless permanent magnet synchronous linear motor mover three 404 is fixed to the middle of slide three 405 by screw connection; grating scale fixed length three 406 is fixed to one side of supporting member two 401 by screw connection; grating scale reading head three 407 is fixed to L-shaped support frame two 408 by screw connection; L-shaped support frame two 408 is fixed to one side of slide three 405 by screw connection; limit switch two 409 is fixed to one side of supporting member two 401 by screw connection; Z-shaped baffle two 412 is fixed to one side of slide three 405 by screw connection; both ends of accordion cover two 411 are respectively fixed to return oil tank two 410 and slide three 405 by screw connection. The beneficial effect is that the coreless permanent magnet synchronous linear motor mover three 404 drives the slide three 405 to move linearly along the coreless permanent magnet synchronous linear motor stator three 403, and the grating scale reading head three 407 feeds back the position and speed information of the slide three 405 to complete the translational motion in the Z-axis direction.
[0087] like Figure 7As shown, the B-axis rotation module 5 includes an upper thrust plate 501, an oil retaining ring 502, a thrust bearing 503, a radial bearing 504, a rotating shaft 505, a lower thrust plate 506, a sleeve 507, a torque motor mover 508, a torque motor stator 509, a torque motor stator bracket 510, a turntable base 511, a rotating shaft connecting member 512, a circular grating reading head 513, and a circular grating fixed scale 514; the rotating shaft connecting member 512 is fixed to the middle of the turntable base 511 by a key connection; the circular grating reading head 513 is fixed to the rotating shaft connecting member 512 by a screw connection; the circular grating fixed scale 514 is fixed to the turntable base 511 by a key connection; the rotating shaft 505 The shaft connector 512 is fixed to the shaft through a key connection; the sleeve 507 is fixed to the shaft 505 through a key connection; the torque motor mover 508 is fixed to the sleeve 507 through a screw connection; the torque motor stator 509 is fixed to the torque motor stator bracket 510 through a screw connection; the torque motor stator bracket 510 is fixed to the turntable base 511 through a screw connection; the lower thrust plate 506 is fixed to the turntable base 511 through a screw connection; the upper thrust plate 501 is fixed to the shaft 505 through a key connection; the thrust bearing 503 is fixed to the turntable base 511 through a screw connection; and the radial bearing 504 is installed between the thrust bearing 503 and the shaft 505. The beneficial effect is that the torque motor mover 508 drives the shaft 505 to rotate, the shaft 505 drives the upper thrust plate 501 to rotate, and the circular grating reading head 513 feeds back the angular displacement of the shaft 505 to complete the rotation of the B axis.
[0088] like Figure 8 As shown, the laser heating ultrasonic vibration assisted turning module 7 includes a hexagonal bracket 701, a bottom plate 702, a parabolic flexible hinge 703, a Langevin vibrator 704, a laser isolator 705, and a three-axis precision displacement stage 706; the hexagonal bracket 701 is fixed to the bottom plate 702 by screw connection; the Langevin vibrator is fixed in the hexagonal bracket 701 by screw connection; the parabolic flexible hinge 703 is fixed to the Langevin vibrator 704 by bolt connection; the three-axis precision displacement stage 706 is fixed inside the hexagonal bracket 701 by screw connection; and the laser isolator 705 is fixed to the three-axis precision displacement stage 706 by screw connection. The beneficial effect is that the hexagonal bracket 701 provides a balanced force for the Langevin vibrator 704, and the laser isolator 705 can be fine-tuned through the three-axis precision displacement stage 706 to improve the processing accuracy, significantly reduce the influence of adverse thermal effects, and reduce cutting force and sub-surface damage.
[0089] like Fig. 9As shown, the laser heating ultrasonic vibration assisted milling module 8 includes a bottom plate 801, an ultrasonic vibrator bracket 802, an ultrasonic vibrator 803, a milling cutter bracket 804, a column 805, a motor 806, an arc rotating shaft 807, an arc guide rail 808, a slide plate 809, a laser isolator 810, and a motor 811; the ultrasonic vibrator bracket 802 is fixed to the bottom plate 801 by screw connection; the milling cutter bracket 804 is fixed to the bottom plate 801 by screw connection; the column 805 The first motor 806 is fixed to the left column 805 by screw connection; one end of the arc-shaped rotating shaft 807 is connected to the first motor 806, and the other end is connected to the right column 805; the arc-shaped guide rail 808 is fixed to the arc-shaped rotating shaft 807 by screw connection; the second motor 811 is fixed to the fourth slide 809 by screw connection; the fourth slide 809 is installed on the arc-shaped guide rail 808; the second laser isolator 810 is fixed to the fourth slide 809 by screw connection. The beneficial effect is that the first motor 806 controls the rotation of the arc-shaped rotating shaft 807, and the second motor 811 controls the fourth slide 809 to move along the arc-shaped guide rail 808, so as to realize the preheating of the workpiece in all directions and at multiple angles.
Claims
1. Laser heating ultrasonic vibration assisted ultra-precision turning and milling machine tool, characterized in that: The invention comprises a self-leveling air-floating vibration isolation platform (1), an X-axis translation module (2), a Y-axis translation module (3), a Z-axis translation module (4), a B-axis rotation module (5), a C-axis rotation module (6), a laser heating ultrasonic vibration assisted turning module (7), a laser heating ultrasonic vibration milling auxiliary module (8), and a heat preservation cover module (9); the X-axis translation module (2) and the Z-axis translation module (4) are both placed on the self-leveling air-floating vibration isolation platform (1), and the Y-axis translation module (3) is screwed to the self-leveling air-floating vibration isolation platform (1). The module is connected and fixed to the X-axis translation module (2); the C-axis rotation module (6) is fixed to the Y-axis translation module (3) by screw connection; the B-axis rotation module (5) is fixed to the Z-axis translation module (4) by screw connection; the laser heating ultrasonic vibration assisted turning module (7) and the laser heating ultrasonic vibration milling module (8) are both fixed to the B-axis rotation module (5) by screw connection; and the heat preservation cover module (9) is fixed to the self-leveling air-floating vibration isolation platform (1) by screw connection.
2. The laser heating ultrasonic vibration assisted ultra-precision turning and milling machine tool according to claim 1, characterized in that: The self-leveling air-floating vibration isolation platform 1 comprises a marble base (101), an L-shaped support frame (102), a self-leveling air-floating vibration isolator (103), an I-shaped support frame (104), and an adjusting anchor bolt (105); four adjusting anchor bolts (105) are fixed to the bottom of the I-shaped support frame (104) by screw connection; four self-leveling air-floating vibration isolators (103) are fixed to the top of the I-shaped support frame (104) by screw connection; four L-shaped support frames (102) are fixed to the self-leveling air-floating vibration isolators (103) by screw connection; and the marble base (101) is placed on the L-shaped support frame (102).
3. The laser heating ultrasonic vibration assisted ultra-precision turning and milling machine tool according to claim 1, characterized in that: The X-axis translation module 2 comprises a guide member (201), a guide rail (202), a stator (203) of an ironless permanent magnet synchronous linear motor, a mover (204) of an ironless permanent magnet synchronous linear motor, a slide (205), a grating scale (206), a grating scale reading head (207), an L-shaped support frame (208), a limit switch (209), an oil return tank (210), an accordion cover (211), and a Z-shaped baffle (212); the guide member (201) is fixed to the oil return tank (210) by screw connection; the stator (203) of the ironless permanent magnet synchronous linear motor is fixed to the middle of the guide member (201) by screw connection; the two guide rails (202) are fixed to the guide member (201) by screw connection; the slide A (205) is mounted on a guide rail (202); a coreless permanent magnet synchronous linear motor mover (204) is fixed to the middle of a slide (205) by screw connection; a grating scale fixed length (206) is fixed to one side of a guide member (201) by screw connection; a grating scale reading head (207) is fixed to an L-shaped support frame (208) by screw connection; an L-shaped support frame (208) is fixed to one side of a slide (205) by screw connection; a limit switch (209) is fixed to one side of a guide member (201) by screw connection; a Z-shaped baffle (212) is fixed to one side of a slide (205) by screw connection; and both ends of an accordion cover (211) are fixed to an oil return tank (210) and a slide (205) by screw connection, respectively. The Z-axis translation module 4 comprises a second guide member (401), a second guide rail (402), a third iron-core permanent magnet synchronous linear motor stator (403), a third iron-core permanent magnet synchronous linear motor mover (404), a third slide plate (405), a third grating scale fixed length (406), a third grating scale reading head (407), a second L-shaped support frame (408), a second limit switch (409), a second oil return tank (410), a second accordion cover (411), and a second Z-shaped baffle plate (412); the second guide member (401) is fixed to the second oil return tank (410) by screw connection; the third iron-core permanent magnet synchronous linear motor stator (403) is fixed to the middle of the second guide member (401) by screw connection; the two second guide rails (402) are fixed to the second guide member (401) by screw connection; the slide plate The third (405) is installed on the guide rail second (402); the coreless permanent magnet synchronous linear motor mover third (404) is fixed to the middle of the slide third (405) by screw connection; the grating scale fixed length third (406) is fixed to one side of the guide member second (401) by screw connection; the grating scale reading head third (407) is fixed to the L-shaped support frame second (408) by screw connection; the L-shaped support frame second (408) is fixed to one side of the slide third (405) by screw connection; the limit switch second (409) is fixed to one side of the guide member second (401) by screw connection; the Z-shaped baffle second (412) is fixed to one side of the slide third (405) by screw connection; and the two ends of the accordion cover second (411) are respectively fixed to the return oil tank second (410) and the slide third (405) by screw connection.
4. The laser heating ultrasonic vibration assisted ultra-precision turning and milling machine tool according to claim 1, characterized in that: The Y-axis translation module 3 comprises a gravity-balanced frictionless cylinder (301), an upper end cover (302), a thrust plate (303), a side plate (304), an anti-collision plate (305), a second stator of an iron-core permanent magnet synchronous linear motor (306), a second mover of an iron-core permanent magnet synchronous linear motor (307), a second grating scale fixed scale (308), a second grating scale reading head (309), a second slide plate (310), a lower end cover (311), and a rear end cover (312); the internal connecting rod of the gravity-balanced frictionless cylinder (301) is fixed to the upper part of the slide plate (310) by screw connection, and the cylinder barrel is fixed to the upper part of the upper end cover by screw connection; the second mover of the iron-core permanent magnet synchronous linear motor (3 07) is fixed to the left side of the slide plate 2 (310) by screw connection; the grating scale reading head 2 (309) is fixed to the right side of the slide plate 2 (310) by screw connection; the thrust plate (303) is fixed to both sides of the upper end cover (302) and the lower end cover (311) by screw connection; the coreless permanent magnet synchronous linear motor stator 2 (306) is fixed to the left thrust plate (303) by screw connection; the grating scale fixed length 2 (308) is fixed to the right thrust plate (303) by screw connection; the side plate (304) is fixed to both sides of the thrust plate (303) by screw connection; the rear end cover (312) is fixed to the back of the upper end cover (302) and the lower end cover (311) by screw connection.
5. The laser heating ultrasonic vibration assisted ultra-precision turning and milling machine tool according to claim 1, characterized in that: The B-axis rotation module 5 comprises an upper thrust plate (501), an oil retaining ring (502), a thrust bearing (503), a radial bearing (504), a rotating shaft (505), a lower thrust plate (506), a shaft sleeve (507), a torque motor mover (508), a torque motor stator (509), a torque motor stator bracket (510), a turntable base (511), a rotating shaft connecting member (512), a circular grating reading head (513), and a circular grating fixed scale (514); the rotating shaft connecting member (512) is fixed to the middle of the turntable base (511) by a key connection; the circular grating reading head (513) is fixed to the rotating shaft connecting member (512) by a screw connection; the circular grating fixed scale (514) is fixed to the turntable base (511) by a key connection; the rotating shaft (505) ) is fixed to the rotating shaft connector (512) through a key connection; the shaft sleeve (507) is fixed to the rotating shaft (505) through a key connection; the torque motor mover (508) is fixed to the shaft sleeve (507) through a screw connection; the torque motor stator (509) is fixed to the torque motor stator bracket (510) through a screw connection; the torque motor stator bracket (510) is fixed to the turntable base (511) through a screw connection; the lower thrust plate (506) is fixed to the turntable base (511) through a screw connection; the upper thrust plate (501) is fixed to the rotating shaft (505) through a key connection; the thrust bearing (503) is fixed to the turntable base (511) through a screw connection; and the radial bearing (504) is installed between the thrust bearing (503) and the rotating shaft (505).
6. The laser heating ultrasonic vibration assisted ultra-precision turning and milling machine tool according to claim 1, characterized in that: The laser heating ultrasonic vibration assisted turning module 7 comprises a hexagonal bracket (701), a base plate (702), a parabolic flexible hinge (703), a Langevin vibrator (704), a laser isolator (705), and a three-axis precision displacement stage (706); the hexagonal bracket (701) is fixed to the base plate (702) by screw connection; the Langevin vibrator is fixed in the hexagonal bracket (701) by screw connection; the parabolic flexible hinge (703) is fixed to the Langevin vibrator (704) by bolt connection; the three-axis precision displacement stage (706) is fixed inside the hexagonal bracket (701) by screw connection; and the laser isolator (705) is fixed to the three-axis precision displacement stage (706) by screw connection.
7. The laser heating ultrasonic vibration assisted ultra-precision turning and milling machine tool according to claim 1, characterized in that: The laser heating ultrasonic vibration assisted milling module 8 comprises a second bottom plate (801), an ultrasonic vibrator bracket (802), an ultrasonic vibrator (803), a milling cutter bracket (804), a column (805), a first motor (806), an arc-shaped rotating shaft (807), an arc-shaped guide rail (808), a fourth slide (809), a second laser isolator (810), and a second motor (811); the ultrasonic vibrator bracket (802) is fixed to the second bottom plate (801) by screw connection; the milling cutter bracket (804) is fixed to the second bottom plate (801) by screw connection; the column (805) is fixed to the second bottom plate (801) by screw connection; the second motor (81 ... ) is fixed to the marble base (101) by screw connection; motor 1 (806) is fixed to the left column (805) by screw connection; one end of the arc-shaped rotating shaft (807) is connected to motor 1 (806), and the other end is connected to the right column (805); the arc-shaped guide rail (808) is fixed to the arc-shaped rotating shaft (807) by screw connection; motor 2 (811) is fixed to slide plate 4 (809) by screw connection; slide plate 4 (809) is installed on the arc-shaped guide rail (808); laser isolator 2 (810) is fixed to slide plate 4 (809) by screw connection.
8. The control method for the laser heating ultrasonic vibration assisted ultra-precision turning and milling machine tool according to claim 1, characterized in that: The following steps are involved: Step 1: Use precision measuring instruments to measure the blank or semi-finished part to obtain the workpiece point cloud data and initial parameters, and obtain the measurement model through surface reconstruction; Step 2: By matching and comparing the machining allowance values between the measured model and the design model, the geometric information of the design model is analyzed, and the machining process is simulated based on the initial parameters and machining allowance to determine the appropriate machining parameters such as cutting depth, feed rate, and spindle speed; Step 3: Select appropriate ultrasonic system input parameters based on the processing parameters, and determine the tool tip micro-motion trajectory based on the geometric relationship and displacement transmission relationship of each part; Step 4: According to the machining parameters, solve the machining trajectory of the tool, and combine the coordinate transformation method to generate the corresponding NC machining code of the trajectory, which contains the data information of each axis; Step 5: According to the processing parameters, the movement trajectory of the external laser system of the laser heating ultrasonic vibration assisted milling module is solved, and the corresponding NC code is generated by combining the coordinate transformation method; Step 6: Input the machining trajectory NC code into the NC machining machine to perform NC machining of the workpiece; Step 7: Use precision measuring instruments to measure the various parameters of the workpiece surface after processing the semi-finished product or finished product; Step 8: If the parameters of the measured model are within the required accuracy range, the processing is completed; Step 9: If the parameters of the measurement model exceed the range required by the workpiece accuracy, return to step 1 to continue measuring and processing the part and enter the next processing cycle.
9. The control method for the laser-heated ultrasonic vibration-assisted ultra-precision turning-milling machine tool according to claim 8, characterized in that: Step 3: The tool tip micro-motion trajectory is divided into the tool tip micro-motion trajectory of the laser heating ultrasonic vibration assisted turning module and the tool tip micro-motion trajectory of the laser heating ultrasonic vibration assisted milling module; The laser heating ultrasonic vibration assisted turning module is an in-situ laser heating system, which has no effect on the tool micro-motion trajectory. Therefore, the tool micro-motion trajectory is provided by three ultrasonic vibrators. Assuming that the initial coordinates of the tool tip are (0,0,0), the tool tip coordinates after the movement are (x dt ,y dt ,z dt ), the tool micro-motion trajectory is further solved based on the decomposition of the tool motion. This solution process includes the following: (1) With the tool tip initial point as the coordinate origin, a rectangular coordinate system is established. The direction from O0 to P0 is the Z-axis direction, and the direction from O0 to A0 is the X-axis direction. The Y-axis direction is determined according to the Cartesian left-hand coordinate system, and the tool coordinate system is established; (2) The micro-motion of the tool tip is provided by three ultrasonic vibrators. Let f be the frequency, t be the time, A7, A8, and A9 be the amplitudes of the input displacement of the piezoelectric ceramic drive signal, and θ1, θ2, and θ3 be the initial phases with phase difference. The piezoelectric ceramic drive signal can be obtained as: The three ultrasonic vibrators are driven by piezoelectric ceramics to provide displacements z7, z8, and z9, and the driven displacements can be amplified by the amplitude rod. The amplitude rod selected in the present invention can amplify the piezoelectric ceramic driven displacements z7, z8, and z9 by 2 times. Therefore, the displacements provided by the ultrasonic vibrators to the flexible hinge branch are z4=2z7, z5=2z8, and z6=2z9. Since the three ultrasonic vibrators have a certain phase difference, z4, z5, and z6 are different. It can be assumed that z4≤z5≤z6. (3) The flexible hinge branch is a parabolic rod with a rectangular variable cross-section. Taking the flexible hinge branch where the ultrasonic vibrator is located as an example, a local coordinate system is established; the ultrasonic vibrator provides a displacement of z4 and a force of F1 = F[z4(t)]; denote the bending moment, shear force and axial force under unit load respectively, and ER c S, GA, EA represent the bending, shear and tensile stiffness of the branch section respectively; A is the cross-sectional area of the branch, and A = ∫a p 2 cos(arctan(F'(x p )))dx p ;a p is the width of the branch chain; F'(x p ) is the slope equation of any point on the parabola; x p is the horizontal coordinate of each point of the branch in the local coordinate system; k is a coefficient related to the cross-sectional shape; α is the linear expansion coefficient of the material; h is the height of the branch cross section, and h = ∫a p cos(arctan(F'(x p )))dx p ; M, F s 、F N are bending moment, shear force, and axial force respectively; t0 is the temperature change at the rod axis; Δt is the difference in temperature change between the upper and lower edges of the section; R c Axis curvature radius; micro segment axis length ds; S = Ay p is the area moment of the curved rod section about the neutral axis, y p is the distance between the centroid and the neutral axis of the cross section; According to the principle of virtual work, the unit load method can be used to calculate the displacement of a parabolic rod with a variable cross-section under the combined effects of load, temperature change and other factors: According to the formula, the output displacement z1 of the flexible hinge branch can be obtained, and z2 and z3 can be obtained similarly; (4) Since a multi-axis flexible hinge is used, each flexible hinge has three rotational degrees of freedom. The displacements z1, z2, and z3 of the flexible hinge branches can be decomposed into three partial displacements after being transmitted through the flexible hinge. For example, if the angle between the displacement z1 and the XOY plane is α1 and the angle between the displacement z1 and the YOZ plane is β1, then the displacement transmission expression of the flexible hinge is: The same logic applies The displacement in the X and Y directions only changes the horizontal position of the tool tip, so they can be directly added together to obtain the tool tip micro-motion trajectory. (5) The displacement in the Z direction will cause the tool tip to tilt. The three displacements z 11 、z 21 、z 31 They cannot be added directly, so the displacement synthesis process is decomposed into three parts, and the displacement z is 11 、z 21 、z 31 Input to the flexible hinge branch, as shown in Figure 12; where, let the distance from the origin of the flexible hinge tool holder to the initial point of the tool tip be set to l1, and the distance from the coordinate origin to one of the ultrasonic vibrators be l2. According to the geometric relationship of the three sub-processes, the second micro-motion trajectory of the tool tip can be obtained as: (6) Combining the tool tip micro-motion trajectory 1 and tool tip micro-motion trajectory 2, the tool tip micro-motion trajectory equation can be obtained as: The laser heating ultrasonic vibration assisted milling module is a single-excitation ultrasonic vibrator, so the tool micro-motion trajectory is relatively simple. The voltage signal is input to the piezoelectric ceramic piece, and the piezoelectric ceramic piece outputs a corresponding driving signal to cause the ultrasonic vibrator to have a corresponding position change s along the axial direction. The function of the position change s changing with the control voltage is s = F[A(u), f(u), θ(u), u], where A(u) is the amplitude of the ultrasonic vibrator vibration, f(u) is the frequency of the ultrasonic vibrator vibration, and θ(u) is the phase difference of the ultrasonic vibrator vibration, where u = U(t); then substituting u = U(t) into s = F[A(u), f(u), θ(u), u] can obtain the position change of the tool tip. Since there is only one ultrasonic vibrator input, it is also the tool tip micro-motion equation of the laser heating ultrasonic vibration assisted milling module.
10. The control method for the laser-heated ultrasonic vibration-assisted ultra-precision turning-milling machine tool according to claim 8, characterized in that: Step 5: The external laser system of the laser heating ultrasonic vibration assisted milling module needs to be controlled to achieve follow-up heating of the workpiece; the milling cutter tip is used as the coordinate origin, the horizontal direction is the X axis, and the vertical upward direction is the Z axis. The coordinate axis is established according to the Cartesian left-hand coordinate system to determine the Y axis direction; the radius of the arc guide is set as R, and the plane where the arc guide is located is parallel to the x axis. m o m z m The plane angle is γ=γ(t), and the laser isolator is located at any position and x m o m y m The included angle is δ=δ(t), and the column height is h1. Therefore, the geometric relationship allows us to obtain the motion equation of the laser isolator in the tool coordinate system: Laser isolator 2 is symmetrical to laser isolator 1 about the YOZ plane, so the motion equation of laser isolator 2 is: The coordinate transformation method of the laser heating ultrasonic vibration assisted ultra-precision machining turning and milling machine tool is as follows: the center point of the C-axis is the coordinate origin, the upward direction along the vertical axis is the Y-axis, and the direction of the X-axis translation module is the X-axis. The coordinate axis is established according to the Cartesian left-hand coordinate system to determine the Z-axis direction, and then the machine tool coordinate system is established; the distance between the origin of the tool coordinate system and the origin of the machine tool coordinate system along the Z-axis direction of the tool coordinate system is av f t, vertical distance along the X axis is bv y t, the distance along the Y axis is cv x t, v f is the tool feed speed, v y is the Y-axis moving speed of the machine tool, v x is the moving speed of the X axis of the machine tool; when the origin of the tool coordinate system coincides with the origin of the machine coordinate system, the tool coordinate system is first rotated 180° around its X axis and then rotated 90° counterclockwise around its Z axis to coincide with the machine coordinate system; at the same time, the machine coordinate system: tool coordinate system = i:1, so the tool coordinate system can be converted to the machine coordinate system by magnifying the tool coordinate system i times; the tool coordinate system can be converted to the machine coordinate system through the transformation matrix T(cv x t,bv y t,-a+v f t) is converted to the machine tool coordinate system, and the transformation matrix can be expressed as: In addition to the transformation matrix, the coordinate system transformation relationship can be obtained by inferring the position coordinate relationship of any point from the tool coordinate system to the machine tool coordinate system; assuming that the position coordinate of any point in the tool coordinate system is (x d ,y d ,z d ), after the origin of the tool coordinate system coincides with the origin of the machine tool coordinate system, the position coordinate of any point is (x j1 ,y j1 ,z j1 ), so we can get The coordinates of any point after the rotation transformation are (x j2 ,y j2 ,z j2 ), so we can get z j By magnifying it i times, we can get the conversion relationship between the tool coordinate system and the machine tool coordinate system; The turning coordinate system and the milling coordinate system are both tool coordinate systems. The horizontal distance between the origin of the turning coordinate system and the center point of the rotating B axis is l1, and the horizontal distance between the origin of the milling coordinate system and the center point of the rotating B axis is l2. The vertical distance between the turning coordinate system and the milling coordinate system is h2, and the angle difference on the horizontal plane is 90°. The turning coordinate system can be converted to the milling coordinate system through the transformation matrix T1(l1,l2,-h2). The transformation matrix can be expressed as: Therefore, the conversion between the turning coordinate system and the milling coordinate system can be expressed as:
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