An ultra-precision fly-cutting precision tool setting method based on circular groove positioning

Abstract

The present application relates to the technical field of ultra-precision machining, in particular to a kind of ultra-precision fly-cutting precision tool setting method based on circular groove positioning.Diamond tool is installed on the C-axis of ultra-precision machine tool, and the workpiece is clamped on the B-axis.Two specific concentric circular groove structures are fly-cut on the surface of the workpiece, and then the machined workpiece surface is placed under the white light interferometer.The radius of the circular arc corresponding to the lowest point of the two circular grooves is accurately measured.According to the relationship between the actual measured radius, the ideal radius and the tool setting error, an equation is established, and the size of the X-axis and Z-axis tool setting error is calculated.The tool setting error is compensated into the machine tool system, so as to realize ultra-precision fly-cutting precision tool setting.The present application only needs two clamping and trial cutting, without repetitive work as in traditional trial cutting, and improves the tool setting efficiency.

Description

Technical Field

[0001] This invention relates to the field of ultra-precision machining technology, and in particular to an ultra-precision flying cut precision tool setting method based on circular groove positioning. Background Technology

[0002] As a crucial ultra-precision machining technology, ultra-precision flying shear offers high flexibility and determinism in obtaining free-form surfaces, micro / nanostructured surfaces, and mixed-structure surfaces with submicron-level surface accuracy and nanoscale surface roughness. Currently, for specially manufactured free-form surfaces and structural surfaces, ultra-precision flying shear, with its advantages of deterministic high-quality complex surface preparation, cost-effectiveness, and high flexibility, has become one of the most reliable and fastest technologies in optics, medicine, and electronics. Although ultra-precision flying shear technology evolved from ultra-precision turning, its unique machining method (diamond tools mounted on the spindle and workpiece clamped on the B-axis) also introduces corresponding machining problems. In multi-axis ultra-precision machine tool machining, the B-axis enables the workpiece to rotate and position at different angles, linking with other machine tool axes to achieve more refined and complex machining requirements, thereby creating complex workpiece structural surfaces. An uncalibrated and unadjusted B-axis will cause positioning deviations at different angles when machining the workpiece. Cutting position deviations of the tool at different angular positions will directly cause serious defects in the machined optical surfaces. Therefore, eliminating tool setting errors caused by the B-axis in ultra-precision flying shear is essential.

[0003] For ultra-precision flying cut tool setting, the following steps are typically required to determine the relative position of the tool tip center and the B-axis center: First, adjust the tool position and angle according to the machining requirements to eliminate the deflection error between the tool tip center and the B-axis rotation center in the Y-axis direction, and calculate the distance between the tool tip center and the B-axis rotation center in the Y-axis direction; then, obtain the distances between the tool tip center and the B-axis rotation center in the X and Z axes through machining experiments, and compensate and calibrate the tool setting errors in the X and Z axes; finally, transform the coordinates of any point in the machining program to the machine tool coordinate system to determine the corresponding tool tip center position, thereby achieving ultra-precision flying cut tool setting.

[0004] The effectiveness of traditional ultra-precision machine tool flying cut tool setting methods has been widely verified, but the following drawbacks still exist: 1) The trial cut method heavily relies on the operator's skill level, is too subjective, and has low confidence in the results; 2) The trial cut method is cumbersome, consumes a lot of time, cost, and manpower, requires special tools or equipment for data analysis, has too many limitations, prolongs the processing cycle, and the operation process is prone to damage to the workpiece surface due to repeated cutting, which ultimately affects the surface quality; 3) The dedicated B-axis tool setting instrument method has high requirements for operators, requires additional installation space, and is only applicable to specific types or sizes of workpieces, which has obvious limitations; 4) The dedicated B-axis tool setting instrument equipment is expensive and requires subsequent maintenance and calibration, which requires additional time and cost.

[0005] In summary, existing traditional ultra-precision machine tool flying cut tool setting methods cannot meet actual production needs. Summary of the Invention

[0006] To address the problems existing in the prior art, this invention aims to disclose an ultra-precision flying cut tool setting method based on circular groove positioning. This method effectively improves the objectivity and reliability of the tool setting process without affecting normal machining efficiency, while minimizing manpower and costs, ultimately improving the surface quality of ultra-precision machining. To achieve this objective, this invention adopts the following technical solution:

[0007] A method for ultra-precision flying cut tool setting based on circular groove positioning, applied to ultra-precision machine tools, includes:

[0008] The dimensions of the workpiece are determined by using ultra-precision measuring instruments, thereby determining the geometric center of the workpiece. The tool (2) is clamped using a special tool holder and attached to the C-axis (4) of the ultra-precision machine tool by a suction cup. The workpiece is fixed to the B-axis (3) using a professional fixture. The C-axis (4) is rotated so that the tool (2) is perpendicular to the workpiece machining surface (1). The B-axis (3) is moved a certain distance along the Z-axis and the B-axis is rotated to cut the workpiece machining surface (1) and eliminate the Y-axis tool setting error. B-axis (3) rotates at a fixed angle The workpiece is machined sequentially on surface (1). , , Three points; remove the workpiece and clean the machined surface with alcohol and a lint-free cloth (1), measure on an ultra-precision measuring device. , , The distance between the three points along the X-axis is used to adjust the workpiece position and locate the geometric center of the workpiece. and B-axis (3) rotation center Coincident; Set B-axis (3) fixed speed Control the tool (2) to move along the Z-axis. Then, cut the first circular groove along the Y-axis with a cutting depth h (5); after machining, return to the rough setting point, keep the B-axis speed constant, and control the tool (2) to move along the X-axis. ( Then, along the Y-axis, cut the second circular groove (6) with the same cutting depth h; remove the workpiece and clean the machined surface with alcohol and a lint-free cloth (1); use an ultra-precision measuring device to measure the radius of the arc at the lowest point of the first circular groove (5). The radius of the arc at the lowest point of the second circular groove (6) is Construct a system of equations for tool setting error and calculate the tool setting error along the X and Z axes. and By incorporating this tool setting error compensation into the machine tool coordinate system, ultra-precision flying cut tool setting can be achieved.

[0009] Optionally, the C-axis of the ultra-precision machine tool is an air spindle; the chuck is a vacuum chuck; the fixture is a pneumatic fixture; the cutting tool is a polycrystalline diamond turning tool; the dedicated tool holder is a high-speed tool holder; and the ultra-precision measuring instrument is a white light interferometer.

[0010] Optionally, the B-axis (3) rotates at a fixed angle. The workpiece is machined sequentially on surface (1). , , Three points, specifically: controlling the B-axis (3) to rotate at a fixed angle. The angle is 30°. Based on the principle that the center of a circle is determined by three points on the same plane, a structure is constructed. , , The system of equations relating the three points to the center of rotation along the B-axis can be used to obtain the coordinates of the center of rotation along the B-axis.

[0011] Optional, set (0, 0), ( , ), ( , ), , , The distances between the three points and the center of rotation along the B-axis are: B-axis rotation center coordinates ( , The system of equations to be solved is specifically as follows:

[0012]

[0013]

[0014]

[0015]

[0016]

[0017] Optionally, the coordinates of the B-axis rotation center to be solved are specifically as follows:

[0018]

[0019]

[0020] Optionally, the controlled tool (2) moves along the Z-axis. Specifically, the tool (2) moves 10mm along the positive Z-axis and then moves along the Y-axis with a cutting depth h, h being 4μm. The B-axis (3) is rotated to cut the first circular groove (5).

[0021] Optionally, the controlled tool (2) moves along the X-axis. Specifically, the tool (2) moves 15mm along the positive direction of the X-axis, and then moves along the Y-axis with a cutting depth h, h being 4μm, and rotates the B-axis (3) to cut the second circular groove (6).

[0022] Optionally, the white light interferometer measures the circular grooves and records the radius of the lowest point of the first circular groove (5) and the second circular groove (6). , Specifically, this includes: removing the workpiece and cleaning the workpiece's machined surface (1); measuring the radius of the lowest point of the first circular groove (5) and the second circular groove (6) on a surface measuring device along the positive Z-axis, and recording it as follows: , .

[0023] Optionally, the step of constructing a set of tool setting error equations to calculate the tool setting error along the X-axis and Z-axis directions is described. and By incorporating this tool setting error compensation into the machine tool coordinate system, ultra-precision flying cut tool setting can be achieved. Specifically, this includes: flying cut after moving along the X and Z axes; establishing distances along the X and Z axes. , The lowest point of the arc radius of the first circular groove (5) and the second circular groove (6) , and tool setting error along the X and Z axes and The system of equations between them; solving this system of equations will yield the tool setting errors in the X and Z axes. and By incorporating this tool setting error compensation into the machine tool coordinate system, ultra-precision flying cut tool setting can be achieved.

[0024] Optionally, the system of equations to be solved is specifically as follows:

[0025]

[0026]

[0027] The beneficial effects of this invention are as follows:

[0028] This invention discloses an ultra-precision flying cut tool setting method based on circular groove positioning. Two specific concentric circular groove structures are machined on the workpiece surface using a diamond turning tool. The machined workpiece surface is then placed under a white light interferometer to precisely measure the arc radius corresponding to the lowest point of the two circular grooves. Based on the actual measured radius, the ideal radius, and the tool setting error... , The relationship between the X and Z axes is established by formulating equations to calculate the tool setting errors. These errors are then compensated for in the machine tool system for subsequent machining. This method has the following advantages: First, the proposed circular groove positioning method is independent of the operator's skill level, based on objective operation, resulting in higher confidence. Second, the high-precision white light interferometer measurement overcomes the limited accuracy range of traditional microscope measurements, making the measurement process efficient, fast, and yielding high-precision results. Furthermore, the proposed method requires only two clamping and trial cuts, eliminating the need for repetitive work like traditional trial cuts, thus improving tool setting efficiency. Importantly, this method solves the problems of cumbersome operation, significant limitations, time consumption, cost, and manpower required by traditional methods, enabling ultra-precision flying cut tool setting with improved operability and efficiency. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of steps 2 and 3 of the ultra-precision flying cut tool setting method based on circular groove positioning according to the present invention;

[0030] Figure 2 This is a schematic diagram of step 4 of the ultra-precision flying cut tool setting method based on circular groove positioning according to the present invention;

[0031] Figure 3 This is a schematic diagram of step 6 of the ultra-precision flying cut tool setting method based on circular groove positioning according to the present invention;

[0032] Figure 4 This is a first schematic diagram of step 6 of the ultra-precision flying cut tool setting method based on circular groove positioning according to the present invention;

[0033] Figure 5 This is a second schematic diagram of step 8 of the ultra-precision flying cut tool setting method based on circular groove positioning of the present invention;

[0034] In the diagram: 1. Workpiece machined surface; 2. Polycrystalline diamond cutting tool; 3. Machine tool B-axis; 4. Machine tool C-axis; 5. First circular groove; 6. Second circular groove. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0036] It should be noted that the B-axis and C-axis of a machine tool refer to the solid components of an ultra-precision machine tool. For example... Figure 1 As shown, in the machine tool coordinate system, the B-axis of the machine tool rotates around the Y-axis, and the C-axis of the machine tool rotates around the Z-axis.

[0037] Example:

[0038] Please see Figure 1-5 This invention discloses an ultra-precision flying cut tool setting method based on circular groove positioning, comprising the following steps:

[0039] S1: Determine the workpiece dimensions using ultra-precision measuring instruments, thereby determining the workpiece's geometric center. In this embodiment, the ultra-precision measuring instrument is a white light interferometer. Its working principle is to measure the wavelength of light or the surface morphology of optical elements by utilizing the interference phenomenon. When white light is split into two beams by a beam splitter, the two beams propagate through different paths and then recombine to produce interference fringes. By observing the changes in the interference fringes, the corresponding physical quantities can be measured. It has the advantages of high resolution, multifunctionality, high sensitivity, and ease of operation.

[0040] like Figure 1 As shown, S2: The tool is clamped using a dedicated tool holder and attached to the C-axis of the ultra-precision machine tool by a suction cup. The workpiece is fixed to the B-axis using a professional fixture. The C-axis is rotated so that the tool is perpendicular to the workpiece machining surface. Let the tool tip position be A, and the rotation center point of the B-axis be [missing information]. The distance between the tool tip and the center of rotation of the B-axis is . The projection of the tool tip point A onto the X and Z axes, i.e., the tool setting error along the X and Z axes, is: and In this embodiment, a polycrystalline diamond turning tool is used. Polycrystalline diamond turning tools have extremely high hardness and wear resistance, excellent cutting performance and stability, and are suitable for ultra-precision machining. In this invention, the tool is clamped on a dedicated tool holder and held in place by a suction cup device. This embodiment uses a vacuum suction cup, a device that uses vacuum principles to generate negative pressure to attract components. It has advantages such as high-precision clamping, high stability, wide applicability, no damage, high automation, and energy saving. This embodiment uses a high-speed tool holder suitable for high-speed cutting and precision machining, which can improve machining efficiency and quality. In this invention, the workpiece is fixed on the B-axis using a professional fixture. This embodiment uses a pneumatic fixture to position and clamp the workpiece. The pneumatic fixture controls the clamping force through air pressure, featuring flexible and rapid adjustment of clamping force, suitable for clamping workpieces of various shapes and sizes, and particularly suitable for high-precision machining.

[0041] like Figure 1 As shown, S3: Move the workpiece a certain distance along the Z-axis and rotate the B-axis to perform workpiece surface cutting. After machining, set the corresponding machine tool Y-axis coordinate value to the Y-axis zero point to eliminate Y-axis tool setting error. Let the center of rotation of the C-axis be noted at this point. Distance to workpiece surface is ;

[0042] like Figure 2 As shown, S4: Based on the principle of determining the center of a circle by three points on the same plane, the tool tip position is fixed, and the B-axis is rotated at a fixed angle. Processing sequentially on the surface of the workpiece , , Three points. Let's assume... (0, 0), ( , ), ( , ), , , The distances between the three points and the center of rotation along the B-axis are: B-axis rotation center coordinates ( , The coordinate relationship between the three points and the rotation center of axis B is as follows:

[0043]

[0044]

[0045]

[0046]

[0047]

[0048] Combining the above equations, we get:

[0049]

[0050]

[0051] S5: Remove the workpiece, clean the machined surface with alcohol and a lint-free cloth, and measure on an ultra-precision measuring device. , , The distance between the three points is used to determine the coordinates of the rotation center on the B-axis. According to the geometric center of the workpiece and B-axis rotation center Based on the positional relationship, adjust the workpiece position and set the workpiece geometric center... and B-axis rotation center coincide;

[0052] like Figure 3 , Figure 4 As shown, S6: Move the B-axis to the coarse tool setting point and set the B-axis to a fixed speed. , with the knife Move the reference coordinate point along the Z-axis. Let this position be E. At this position, cut the first circular groove along the Y-axis with a cutting depth h. After machining, return to the roughing point, keep the B-axis speed constant, and move the tool... Move the reference coordinate point along the X-axis ( Let this position be F. At this position, a second circular groove is cut along the Y-axis with the same cutting depth h. In this embodiment, the cutting depth of the first and second circular grooves is the same to ensure that the lowest point of the first and second circular grooves is selected according to the same standard when measured by a white light interferometer, facilitating the acquisition of measurement results and subsequent data processing. In this embodiment, the tool uses... The reference coordinate points are moved at different distances along the X-axis and Z-axis. This is to facilitate the measurement of the tool setting error between the tool tip center and the B-axis rotation center along the X-axis and Z-axis directions, and to prevent interference between the two machined circular grooves, thus avoiding inconvenience in subsequent measurements.

[0053] S7: After machining is completed, the tool is retracted to the rough setting point, the workpiece is removed, the machined surface is cleaned with alcohol and a lint-free cloth, and the measurement is performed under ultra-precision measuring equipment. The measurement results are then processed in a relative coordinate system.

[0054] like Figure 5As shown, S8: The first and second circular grooves are measured using a measuring instrument, and the radius of the arc at the lowest point of the first circular groove is obtained as follows: The radius of the arc at the lowest point of the second circular groove is Combining tool setting errors along the X and Z axes and The distance the tool travels along the X and Z axes , The following equation can be established:

[0055]

[0056]

[0057] Combining the above equations, we can obtain the tool setting errors along the X-axis and Z-axis. and size;

[0058] S9: By incorporating this tool setting error compensation into the machine tool coordinate system, ultra-precision flying cut tool setting can be achieved.

[0059] The above method for ultra-precision flying cut tool setting offers several advantages: First, it eliminates reliance on operator experience and skill level, making the method simple, easy to implement, and objective. Second, trial cuts require only a single clamping and cutting, eliminating repetitive operations and reducing clamping errors, thus improving tool setting efficiency. Importantly, this method solves the problems of traditional methods being cumbersome, limited, time-consuming, costly, and labor-intensive, enabling ultra-precision flying cut tool setting with improved operability and efficiency.

[0060] The above are embodiments of the present invention. The above embodiments and specific parameters are only for clearly illustrating the invention verification process and are not intended to limit the patent protection scope of the present invention. The patent protection scope of the present invention shall still be determined by its claims. Similarly, any equivalent structural changes made based on the description and drawings of the present invention shall also be included within the protection scope of the present invention.

Claims

1. A method for ultra-precision flying cut tool setting based on circular groove positioning, applied to ultra-precision machine tools, characterized in that, include: The dimensions of the workpiece are determined by using ultra-precision measuring instruments, thereby determining the geometric center of the workpiece. The tool (2) is clamped using a special tool holder and attached to the C-axis (4) of the ultra-precision machine tool by a suction cup. The workpiece is fixed to the B-axis (3) using a professional fixture. The C-axis (4) is rotated so that the tool (2) is perpendicular to the workpiece machining surface (1). The B-axis (3) is moved a certain distance along the Z-axis and the B-axis is rotated to cut the workpiece machining surface (1) and eliminate the Y-axis tool setting error. B-axis (3) rotates at a fixed angle The workpiece is machined sequentially on surface (1). , , Three points; remove the workpiece and clean the machined surface with alcohol and a lint-free cloth (1), measure on an ultra-precision measuring device. , , The distance between the three points along the X-axis is used to adjust the workpiece position and locate the geometric center of the workpiece. and B-axis (3) rotation center coincide; Set B-axis (3) to a fixed speed. Control the tool (2) to move along the Z-axis. Then, cut the first circular groove along the Y-axis with a cutting depth h (5); after machining, return to the rough setting point, keep the B-axis speed constant, and control the tool (2) to move along the X-axis. ( Then, along the Y-axis, cut the second circular groove (6) with the same cutting depth h; remove the workpiece and clean the machined surface with alcohol and a lint-free cloth (1); use an ultra-precision measuring device to measure the radius of the arc at the lowest point of the first circular groove (5). The radius of the arc at the lowest point of the second circular groove (6) is ; Construct a system of equations for tool setting error and calculate the tool setting error along the X and Z axes. and By incorporating this tool setting error compensation into the machine tool coordinate system, ultra-precision flying cut tool setting can be achieved.

2. The method as described in claim 1, characterized in that, The ultra-precision machine tool's C-axis is an air spindle; the chuck is a vacuum chuck; the clamp is a pneumatic clamp; the cutting tool is a polycrystalline diamond turning tool; the dedicated tool holder is a high-speed tool holder; and the ultra-precision measuring instrument is a white light interferometer.

3. The method as described in claim 1, characterized in that, B-axis (3) rotates at a fixed angle The workpiece is machined sequentially on surface (1). , , Three points, specifically: controlling the B-axis (3) to rotate at a fixed angle. The angle is 30°. Based on the principle that the center of a circle is determined by three points on the same plane, a structure is constructed. , , The system of equations relating the three points to the center of rotation along the B-axis can be used to obtain the coordinates of the center of rotation along the B-axis.

4. The method as described in claim 3, characterized in that, set up (0, 0), ( , ), ( , ), , , The distances between the three points and the center of rotation along the B-axis are: B-axis rotation center coordinates ( , The system of equations to be solved is specifically as follows: 。 5. The method as described in claim 3, characterized in that, The specific coordinates of the B-axis rotation center to be solved are: 。 6. The method as described in claim 1, characterized in that, The controlled tool (2) moves along the Z-axis. Specifically, the tool (2) moves 10mm along the positive Z-axis and then moves along the Y-axis with a cutting depth h, h being 4μm. The B-axis (3) is rotated to cut the first circular groove (5).

7. The method as described in claim 1, characterized in that, The controlled tool (2) moves along the X-axis. Specifically, the tool (2) moves 15mm along the positive direction of the X-axis, and then moves along the Y-axis with a cutting depth h, h being 4μm, and rotates the B-axis (3) to cut the second circular groove (6).

8. The method as described in claim 2, characterized in that, The white light interferometer measures the circular grooves and records the radius of the lowest point of the first circular groove (5) and the second circular groove (6). , Specifically, this includes: removing the workpiece and cleaning the workpiece's machined surface (1); measuring the radius of the lowest point of the first circular groove (5) and the second circular groove (6) on a surface measuring device along the positive Z-axis, and recording it as follows: , .

9. The method as described in claim 1, characterized in that, The tool setting error equation system is constructed to calculate the tool setting error along the X-axis and Z-axis directions. and By incorporating this tool setting error compensation into the machine tool coordinate system, ultra-precision flying cut tool setting can be achieved. Specifically, this includes: flying cut after moving along the X and Z axes; establishing distances along the X and Z axes. , The lowest point of the arc radius of the first circular groove (5) and the second circular groove (6) , and tool setting error along the X and Z axes and The system of equations between them; solving this system of equations will yield the tool setting errors in the X and Z axes. and By incorporating this tool setting error compensation into the machine tool coordinate system, ultra-precision flying cut tool setting can be achieved.

10. The method as described in claim 9, characterized in that, The system of equations to be solved is specifically as follows: 。

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