A device for measuring spindle rotation deviation based on optical interference

Abstract

The present invention provides a spindle rotation deviation measurement device based on optical interference, comprising a rotation angle measurement assembly, a displacement measurement assembly, a pitch angle measurement assembly, and a posture detection optical interference module. The rotation angle measurement assembly comprises a fixed base, a rotating base, and a rotation angle measurement optical interference module, wherein the rotating base is rotatably connected to the fixed base; the rotation angle measurement optical interference module is mounted on the rotating base to measure the rotation angle of the rotating base; the displacement measurement assembly comprises a movable base and a displacement measurement optical interference module, wherein the movable base is slidably mounted on the rotating base; the displacement measurement optical interference module is mounted on the rotating base and the movable base to measure the displacement of the movable base; the pitch angle measurement assembly comprises a pitch base and a pitch angle measurement optical interference module, wherein the pitch base is rotatably mounted on the movable base; the pitch angle measurement optical interference module is mounted on the movable base and the pitch base to measure the swing angle of the pitch base; and the posture detection optical interference module is mounted on the pitch base. This device can improve the accuracy of spindle rotation deviation measurement.

Description

Technical Field

[0001] The invention relates to a measuring device, in particular to a device for measuring spindle rotation deviation based on optical interference. Background Art

[0002] The accuracy of a machine tool directly impacts the precision of the machined workpiece. The spindle is crucial for ensuring this precision. The spindle is a core component of a CNC machine tool, responsible for receiving power from the machine's motor and transmitting it to other machine components. During operation, the spindle must bear a certain load and maintain an appropriate rotational speed, driving the workpiece or tool within its control range around the spindle's centerline. The spindle's rotational accuracy determines the machine tool's machining accuracy.

[0003] The spindle's rotational accuracy is determined by the relative position of its instantaneous rotational centerline to its ideal rotational centerline. During normal spindle operation, the spindle's instantaneous rotational centerline often deviates from its ideal rotational centerline due to mechanical factors such as the manufacturing, assembly, and adjustment precision of the spindle and bearings, the spindle's speed, the design and performance of the bearings, and the dynamic characteristics of the spindle components. During machining, the spindle may experience radial runout perpendicular to the axis or angular oscillation about a point on the axis. These movements can reduce the spindle's rotational accuracy.

[0004] Therefore, when a machine tool is repaired or used to process a new workpiece, it is necessary to check the spindle rotation deviation during operation before formal processing so that the corresponding processing control strategy can be adopted based on the measured data. The existing spindle accuracy measurement methods mainly include:

[0005] (1) Static measurement method: This is a method for measuring the spindle rotation accuracy in a low-speed rotation environment. The specific operation process is to manually rotate the spindle slowly under no-load conditions, or control the spindle to rotate at a low speed, use a micrometer to measure, measure the maximum and minimum degrees, and calculate the difference between the two, which is the spindle rotation accuracy. However, this method has the following disadvantages: First, the static measurement method is performed in a low-speed rotation environment, not at the actual working speed of the spindle. Therefore, it cannot reflect the true spindle rotation accuracy; second, the measurement using a micrometer is a contact measurement. During measurement, the micrometer needs to be against the spindle surface. The micrometer applies a radial force to the spindle that does not exist during actual spindle processing. This radial force will increase the deviation amplitude of the spindle during rotation, affecting the measurement accuracy of the spindle rotation deviation.

[0006] (2) Dynamic measurement method: This is a method that uses a non-contact measuring device to measure the deviation of the spindle during rotation at the actual working speed of the spindle. The commonly used measurement method at present is: a standard sphere is installed on the spindle, and then two displacement sensors are installed at right angles to each other in the two sensitive directions of the spindle movement. When the spindle rotates, the two displacement sensors simultaneously measure the error information of the rotary axis in different sensitive directions. After the measurement signal is amplified, it is processed by a signal analysis instrument or an electronic computer, and the result is output to an oscilloscope or a corresponding error graph surface is drawn. This measurement method can more realistically and comprehensively reflect the rotation accuracy of the spindle. However, it uses a displacement sensor to detect the deviation of the spindle rotation. The measurement accuracy of the displacement sensor is usually only at the micron level. The sensor is usually installed on the base associated with the spindle. It will vibrate with the spindle and will also generate corresponding vibrations, resulting in a reduction in the accuracy of dynamic measurement, which is difficult to meet the needs of some high-precision machine tools. Summary of the Invention

[0007] The present invention aims to solve at least one of the technical problems raised in the above background technology, and provides a spindle rotation deviation measurement device based on optical interference, which can improve the accuracy of the spindle rotation deviation measurement.

[0008] In order to achieve the above object, the technical solution adopted by the present invention is:

[0009] A device for measuring spindle rotation deviation based on optical interference, comprising an angle measurement component, a displacement measurement component, a pitch angle measurement component and an attitude detection optical interference module, wherein the angle measurement component comprises a fixed seat, a rotating seat and an angle measurement optical interference module, wherein the rotating seat is rotatably connected to the fixed seat and can rotate relative to the fixed seat around a first axis; the angle measurement optical interference module is assembled on the rotating seat to measure the rotation angle of the rotating seat; the displacement measurement component comprises a moving seat and a displacement measurement optical interference module, wherein the moving seat is slidably mounted on the rotating seat, and the displacement measurement optical interference module is assembled between the rotating seat and the moving seat The pitch angle measuring module is mounted on the movable seat to measure the displacement of the movable seat sliding relative to the rotating seat; the pitch angle measuring component includes a pitch seat and a pitch angle measuring optical interference module, the pitch seat is rotatably mounted on the movable seat, and can swing around a second axis relative to the movable seat, the second axis is perpendicular to the first axis and the sliding direction of the movable seat, the pitch angle measuring optical interference module is assembled on the movable seat and the pitch seat to measure the swing angle of the pitch seat relative to the movable seat; the attitude detection optical interference module is assembled on the pitch seat to detect whether the rotation angle of the rotating seat, the sliding displacement of the movable seat and the swing angle of the pitch seat are consistent with the deviation of the main axis.

[0010] Furthermore, the rotating seat includes a seat body, a follower gear and two movable racks. The seat body is rotatably connected to the fixed seat, the follower gear is fixed on the seat body, and the center axis of the follower gear is coaxial with the first axis; the two movable racks are slidably mounted on the seat body and respectively engage with the opposite sides of the follower gear, and the angle measurement light interference mode assembly is mounted on the seat body and the two movable racks.

[0011] Furthermore, the angle measurement optical interference module includes an angle measurement light source, an angle measurement spectroscope, an angle measurement right-angle reflector, two angle measurement cone reflectors and an angle measurement photoelectric detector. The angle measurement light source, the angle measurement spectroscope and the angle measurement right-angle reflector are all fixed on the base. The angle measurement spectroscope is installed on the outgoing light path of the angle measurement light source. The angle measurement right-angle reflector is located on the side of the angle measurement spectroscope facing away from the angle measurement light source. The two angle measurement cone reflectors are respectively fixed on two moving racks. The angle measurement photoelectric detector is located on the side of the angle measurement spectroscope facing away from the angle measurement cone reflector. The angle measurement spectrometer reflects part of the output light from the angle measurement light source onto one of the angle measurement corner pyramid prisms, and the light is refracted by the angle measurement corner pyramid prism and then output in parallel, and passes through the angle measurement spectrometer again to be incident on the angle measurement photoelectric detector; the angle measurement spectrometer projects another part of the output light from the angle measurement light source onto the angle measurement right-angle reflector, and the angle measurement right-angle reflector reflects the projected output light onto another angle measurement corner pyramid prism, and then is refracted by the corresponding angle measurement corner pyramid prism and then output in parallel, and passes through the angle measurement right-angle reflector and the angle measurement spectrometer in sequence to be incident on the angle measurement photoelectric detector.

[0012] Furthermore, the displacement measurement optical interference module includes a displacement measurement light source, a displacement measurement spectrometer, a movable reflector, a fixed reflector and a displacement measurement photoelectric detector. The displacement measurement light source, the displacement measurement spectrometer and the movable reflector are all fixed on the movable seat, and the fixed reflector is fixed on the rotating seat. The displacement measurement spectrometer and the fixed reflector are sequentially arranged on the optical path of the light emitted by the displacement measurement light source, and the movable reflector and the displacement measurement photoelectric detector are respectively arranged on opposite sides of the displacement measurement spectrometer; the displacement measurement spectrometer reflects a part of the output light of the displacement measurement light source onto the movable reflector, and after reflection by the movable reflector, it passes through the displacement measurement spectrometer and is incident on the displacement measurement photoelectric detector; the displacement measurement spectrometer projects another part of the output light of the displacement measurement light source along the optical path of the output light of the displacement measurement light source onto the fixed reflector, and after reflection by the fixed reflector, it passes through the displacement measurement spectrometer and is reflected onto the displacement measurement photoelectric detector.

[0013] Furthermore, the spindle rotation deviation measurement device based on optical interference also includes an optical path folding component arranged on the optical path of the output light of the displacement measurement light source and located between the displacement measurement spectrometer and the fixed reflector, the optical path folding component includes two reflector groups arranged relatively spaced apart along the optical path of the output light of the displacement measurement light source, the two reflector groups are respectively fixed on the movable seat and the rotating seat, and a spacing cavity is formed between the two reflector groups; each reflector group includes two rows of first right-angle prisms, a parallelogram reflector and a second right-angle prism; several first right-angle prisms in each row of the first right-angle prisms are arranged along a first direction, the first direction is parallel to the length direction of the spacing cavity, and the first right-angle prisms use the corresponding two right-angle surfaces to generate reflections on the light; the two rows of first right-angle prisms in each reflector group are arranged along a second direction that is perpendicular to both the first direction and the optical path direction of the output light of the displacement measurement light source; the first The oblique surfaces of the right-angle prisms are opposite to each other, and the first right-angle prisms of the two reflector groups are staggered; the parallelogram reflector is arranged between two adjacent first right-angle prisms in one row of the first right-angle prisms; the second right-angle prism is arranged at one end of the corresponding reflector group, and the second right-angle prism and the first right-angle prism are perpendicular to each other, the main cross-section of the second right-angle prism faces the first right-angle prism of the corresponding reflector group, and the second right-angle prism uses the corresponding two right-angle surfaces to reflect light; the oblique surface of the second right-angle prism of each reflector group is opposite to the oblique surfaces of the two rows of first right-angle prisms at the corresponding end of the other reflector group, and the second right-angle prisms of the two reflector groups are respectively located at opposite ends of the optical path folding component; the outgoing light of the displacement measurement light source is incident through the parallelogram reflector of one group of the reflector groups, reflected by multiple first right-angle prisms and second right-angle prisms of the two reflector groups, and then emitted through the parallelogram reflector of the other group of the reflector group.

[0014] Furthermore, the pitch seat includes a support, two fixed gears, two connecting frames and two sliding racks. The support is rotatably mounted on the mobile seat. The two fixed gears are respectively fixed on opposite sides of the support. The two connecting frames are respectively fixedly connected to the mobile seat. The two sliding racks are respectively slidably mounted on the two connecting frames and respectively engage with the two fixed gears. The support is forced to rotate around the second axis, and the two sliding racks are respectively driven to slide by the two fixed gears. The pitch angle measurement optical interference mode assembly is assembled on the mobile seat and the two sliding racks.

[0015] Furthermore, the pitch angle measurement optical interference module includes a pitch angle measurement light source, a pitch angle measurement spectrometer, a first right-angle reflector, a second right-angle reflector, a third right-angle reflector, a first corner cube prism, a second corner cube prism, and a pitch angle measurement photoelectric detector. The pitch angle measurement light source, the pitch angle measurement spectrometer, the first right-angle reflector, the second right-angle reflector, the third right-angle reflector, and the pitch angle measurement photoelectric detector are all fixed on a movable base, and the first corner cube prism and the second corner cube prism are respectively fixed on two sliding racks; the pitch angle measurement spectrometer reflects a portion of the output light of the pitch angle measurement light source onto the first right-angle reflector , and is reflected by the first right-angle reflector and the second right-angle reflector in sequence and is incident on the first corner cube prism, is reflected by the first corner cube prism and is emitted in parallel, and is sequentially passed through the second right-angle reflector, the first right-angle reflector and the pitch angle measurement spectrometer to be transmitted to the pitch angle measurement photoelectric detector; the pitch angle measurement spectrometer projects another part of the light emitted by the displacement measurement light source onto the third right-angle reflector, is reflected by the third right-angle reflector and is incident on the second corner cube prism, is reflected by the second corner cube prism and is emitted in parallel, and is sequentially reflected by the third right-angle reflector and the pitch angle measurement spectrometer to be reflected on the pitch angle measurement photoelectric detector.

[0016] Furthermore, a detection hole for the spindle to move through is provided on the spindle rotation deviation measurement device based on optical interference, and the detection hole passes through the fixed seat, the rotating seat, the movable seat and the pitch seat; the posture detection optical interference module includes a position detection light source, a first beam splitter, a second beam splitter, a third beam splitter, a first reflector, a second reflector, a first photodetector and a second photodetector, all of which are fixed on the pitch seat; the first beam splitter divides the output light of the position detection light source into a first light beam and a second light beam, wherein the first beam splitter reflects the first light beam to the second beam splitter, the second beam splitter divides the first light beam into a first light beam A and a first light beam B, the second beam splitter projects the first light beam A onto the first reflector, and is reflected by the first reflector to the second beam splitter, and the second beam splitter reflects part of the second light beam A The first beam B is projected onto the first photodetector; the second beam splitter reflects the first beam B onto the main axis in the detection hole, the main axis reflects the first beam B onto the second beam splitter, and the second beam splitter projects part of the first beam B onto the first photodetector; the first beam splitter projects the second beam onto the third beam splitter, the third beam splitter splits the second beam into a second beam A and a second beam B, the third beam splitter projects part of the second beam A onto the second reflector, the part of the second beam A is reflected by the second reflector onto the third beam splitter, and the third beam splitter reflects part of the second beam A onto the second photodetector; the third beam splitter reflects the second beam B onto the main axis in the detection hole, the main axis reflects the second beam B onto the third beam splitter, and part of the second beam B passes through the third beam splitter to be projected onto the second photodetector.

[0017] Furthermore, a first through hole coaxial with the first axis is opened through the fixed seat, a second through hole coaxial with the first axis is opened through the rotating seat, a third through hole is opened through the movable seat, and a fourth through hole is opened through the pitch seat. The first through hole, the second through hole, the third through hole and the fourth through hole are connected in sequence to form the detection hole, and the first light beam B and the second light beam B both converge on the central axis of the fourth through hole.

[0018] Furthermore, the attitude detection optical interference module also includes two optical compensation mirrors fixed on the pitch seat, wherein one optical compensation mirror is located between the first reflector and the second beam splitter, and the other optical compensation mirror is located between the first reflector and the third beam splitter.

[0019] Due to the adoption of the above technical solution, the present invention has the following beneficial effects:

[0020] When the above-mentioned spindle rotation deviation measurement device based on optical interference is used, a dynamic measurement method can be used to perform measurement when the spindle is at its actual operating speed. When the spindle rotates, the deviation posture of the spindle rotation is simulated by the rotation of the rotating seat, the movement of the movable seat, and the swing of the pitch seat. During this process, the attitude detection optical interference module can be used to determine whether the rotation angle of the rotating seat, the movement distance of the movable seat, and the pitch angle of the pitch seat are consistent with the spindle deviation posture. During the rotation of the rotating seat, the movement of the movable seat, and the swing of the pitch seat, the rotation angle of the rotating seat, the movement distance of the movable seat, and the pitch angle of the pitch seat can be measured by the angle measurement optical interference module, the displacement measurement optical interference module, and the pitch angle measurement optical interference module. The movement distance corresponds to the radial runout generated when the spindle rotates, the rotation angle corresponds to the azimuth angle generated by the measurement point on the spindle rotating around the Z axis of the machine tool on the working surface of the machine tool, and the pitch angle corresponds to the swing angle of the instantaneous rotation center line of the spindle relative to the Z axis of the machine tool. Since the spindle rotation deviation measuring device based on optical interference uses an angle measuring optical interference module, a displacement measuring optical interference module, a pitch angle measuring optical interference module and a posture detection optical interference module to test the spindle rotation deviation, its accuracy is related to the wavelength of the light source used for interference, and the accuracy can reach the nanometer level. At the same time, the angle measuring optical interference module, the displacement measuring optical interference module, the pitch angle measuring optical interference module and the posture detection optical interference module are all installed on the spindle deviation measuring device based on optical interference without contacting the spindle, and are not affected by the vibration generated when the spindle rotates. The measurement accuracy is improved and can meet the needs of high-precision machine tools. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A perspective view of a spindle rotation deviation measuring device based on optical interference according to a preferred embodiment of the present invention; Figure 2 for Figure 1 A rear view of the spindle rotation deviation measurement device based on optical interference is shown; Figure 3 for Figure 1 A perspective view of the spindle rotation deviation measuring device based on optical interference at another viewing angle; Figure 4 for Figure 3 A perspective view of the spindle rotation deviation measuring device based on optical interference at another viewing angle; Figure 5 for Figure 4 A top view of the spindle rotation deviation measurement device based on optical interference is shown; Figure 6 for Figure 5 The schematic diagram of the cross-sectional structure of the spindle rotation deviation measuring device based on optical interference along line AA is shown; Figure 7 A schematic structural diagram of a fixed base and a rotating base of a spindle rotation deviation measurement device based on optical interference according to a preferred embodiment of the present invention; Figure 8 This is a schematic diagram of the structure inside the rotating base of the spindle rotation deviation measurement device based on optical interference in a preferred embodiment of the present invention. Figure 8 The middle dashed line represents the light beam; Figure 9 A schematic structural diagram of a fixed base, a rotating base, and a pitching base of a spindle rotation deviation measurement device based on optical interference according to a preferred embodiment of the present invention; Figure 10 This is a schematic diagram of the internal structure of the rotating base and the moving base of the spindle rotation deviation measurement device based on optical interference in a preferred embodiment of the present invention. Figure 10 The middle dashed line represents the light beam; Figure 11 for Figure 10 Schematic diagram of the top view of the structure, Figure 11 The middle dashed line represents the light beam; Figure 12 for Figure 11 Schematic diagram of the cross-section structure along line BB, Figure 12 The middle dashed line represents the light beam; Figure 13 A perspective view of an optical path folding assembly in a spindle rotation deviation measurement device based on optical interference according to a preferred embodiment of the present invention; Figure 14 for Figure 13 A stereoscopic view of the optical path folding assembly at another viewing angle; Figure 15 for Figure 13 A top view of the optical path folding assembly is shown, where a light beam entering the optical path folding assembly moves along optical path A; Figure 16 for Figure 13 A right side view of the optical path folding assembly shown; Figure 17 for Figure 13 A bottom view of the optical path folding assembly shown; Figure 18 for Figure 13 A left side view of the optical path folding assembly shown; Figure 19 for Figure 13 A top view of the optical path folding assembly is shown, where the light beam entering the optical path folding assembly is emitted along optical path E; Figure 20 for Figure 18A schematic diagram of the optical path folding assembly after one reflector group moves relative to another reflector group; Figure 21 for Figure 5 Schematic diagram of the structure after removing part of the pitch seat and the outer cover of one of the attitude detection optical interference modules. Figure 21 The middle dashed line represents the light beam; Figure 22 (a) is a light energy distribution diagram detected by the first photodetector in the initial state, in which the X-axis is parallel to the width direction of the movable base 21, and the Y-axis is parallel to the first axis; Figure 22 (b) is a light energy distribution diagram detected by the second photodetector in the initial state, in which the X-axis of the light energy distribution diagram detected by the second photodetector is parallel to the length direction of the movable base 21, and the Y-axis is parallel to the first axis; Figure 23 (a) is the light energy distribution diagram detected by the first photodetector after the spindle rotation deviates. Figure 22 (b) is the light energy distribution diagram detected by the second photodetector after the main axis rotation deviates; Figure 24 (a) is the light energy distribution diagram detected by the first photodetector after the rotating base is adjusted into place. Figure 24 (b) is a diagram showing the light energy distribution detected by the second photodetector after the rotating base is adjusted into position; Figure 25 (a) is the light energy distribution diagram detected by the first photodetector after the pitch seat is adjusted into place. Figure 25 (b) is a diagram showing the light energy distribution detected by the second photodetector after the pitch mount is adjusted into place; Figure 26 (a) is the light energy distribution diagram detected by the first photodetector after the moving base is adjusted into place. Figure 26 (b) is a diagram showing the light energy distribution detected by the second photodetector after the movable base is adjusted into position; Figure 27 Schematic diagram for calculating the rotation angle of the rotating seat; Figure 28 Schematic diagram for calculating the pitch seat swing angle;

[0022] Description of main component symbols

[0023] 10. Angle measurement assembly; 12. Fixed seat; 120. First through hole; 14. Rotating seat; 140. Seat body; 141. Slideway; 142. Second through hole; 143. Mounting cavity; 145. Follower gear; 146. Moving rack; 147. Mounting block; 16. Angle measurement optical interference module; 161. Angle measurement light source; 162. Angle measurement spectroscope; 163. Angle measurement right-angle reflector; 164. Angle measurement pyramid reflector; 165. Angle measurement photoelectric detector; 167. Window mirror; 17. Rotating drive member; 171. Driven gear; 172. Rotating drive motor; 173. Worm gear; 20. Displacement measurement 21. Displacement measurement component; 211. Moving seat; 213. Guide rail; 214. Third through hole; 215. Receiving groove; 216. Fixed groove; 217. Light hole; 23. Displacement measurement optical interference module; 231. Displacement measurement light source; 232. Displacement measurement spectroscope; 233. Fixed reflector; 234. Moving reflector; 235. Displacement measurement photoelectric detector; 24. Optical path folding component; 240. Reflector group; 241. Spacer cavity; 242. First right-angle prism; 243. Parallelogram reflector; 244. Second right-angle prism; 245. Right-angle surface; 246. Inclined surface; 247. Reflection surface; 248. Incident and exit surfaces; 249, main cross section; 25, mobile drive mechanism; 251, screw motor; 253, screw; 30, pitch angle measurement assembly; 31, pitch seat; 310, support; 311, fourth through hole; 312, fixed cavity; 313, fixed gear; 315, connecting frame; 317, sliding rack; 32, connecting mechanism; 321, fixed ear; 323, connecting shaft; 34, pitch angle measurement optical interference module; 341, pitch angle measurement light source; 342, pitch angle measurement spectrometer; 343, first right-angle reflector; 344, second right-angle reflector; 345, third right-angle reflector; 346, first corner cube; 3 47. Second corner cone prism; 348. Pitch angle measurement photoelectric detector; 349. Fourth right-angle reflector; 36. Swing drive member; 361. Swing drive motor; 363. Drive gear; 365. Passive gear; 40. Posture detection optical interference module; 41. Position detection light source; 42. First beam splitter; 43. Second beam splitter; 44. Third beam splitter; 45. First reflector; 46. Second reflector; 47. First photodetector; 48. Second photodetector; 491. Cylindrical mirror; 492. Optical compensation mirror; 400. Outer cover; 50. First axis; 60. Second axis; 70. Detection hole; 200. Main axis. DETAILED DESCRIPTION

[0024] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0025] It should be noted that when a component is referred to as being "fixed to" another component, it may be directly on the other component or there may also be a central component. When a component is considered to be "connected to" another component, it may be directly connected to the other component or there may also be a central component. When a component is considered to be "set on" another component, it may be directly set on the other component or there may also be a central component. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains. The terms used in this specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0027] See Figure 1 A preferred embodiment of the present invention provides a spindle rotation deviation measurement device based on optical interference, including an angle measurement component 10, a displacement measurement component 20, a pitch angle measurement component 30 and an attitude detection optical interference module 40.

[0028] Please also see Figure 5 、 Figures 6 to 8The angle measurement assembly 10 includes a fixed base 12, a rotating base 14 and an angle measurement optical interference module 16. The fixed base 12 is used to be fixedly connected to an external bracket (not shown). A first through hole 120 is formed on the fixed base 12. The rotating base 14 is rotatably connected to the fixed base 12 and can rotate relative to the fixed base 12 around a first axis 50. The first axis 50 is coaxial with the central axis of the first through hole 120. The angle measurement optical interference module 16 is mounted on the rotating base 14 to measure the rotation angle of the rotating base 14. In this embodiment, the rotating base 14 includes a base body 140, a follower gear 145 and two movable racks 146 slidably connected to the base body 14. The base body 140 is rotatably connected to the fixed base 12. In this embodiment, a second through hole 142 is formed at the approximate center position of the base body 140, one end of which is connected to the first through hole 120. The central axis of the second through hole 142 is coaxial with the first axis 50. The base 140 of the rotating base 14 defines a mounting cavity 143 for mounting the angle measurement optical interferometer module 16. A follower gear 145 is secured within the mounting cavity 143 of the base 140. The central axis of the follower gear 145 is coaxial with the first axis 50. Two movable racks 146 are slidably mounted parallel to and within the mounting cavity 143 of the base 140, meshing with opposite sides of the follower gear 145.

[0029] In this embodiment, the angle measurement optical interferometer module 16 is mounted on the rotating base 14 and housed within the mounting cavity 143. This allows the rotating base 14 to better protect the angle measurement optical interferometer module 16. Specifically, the angle measurement optical interferometer module 16 is mounted on the base 140 and two movable racks 146. In this embodiment, the angle measurement optical interferometer module 16 includes an angle measurement light source 161, an angle measurement beam splitter 162, an angle measurement right-angle reflector 163, two angle measurement corner cube reflectors 164, and an angle measurement photodetector 165. The angle measurement light source 161, the angle measurement beam splitter 162, and the angle measurement right-angle reflector 163 are all fixed within the mounting cavity 143 of the base 140. The angle measurement light source 161 preferably uses a laser emitter, the angle measurement spectrometer 162 is arranged on the output light path of the angle measurement light source 161, the angle measurement right-angle reflector 163 is located on the side of the angle measurement spectrometer 162 facing away from the angle measurement light source 161, the two angle measurement corner cone reflection prisms 164 are both accommodated in the installation cavity 143 and are respectively fixed on the two movable racks 146, and the angle measurement photoelectric detector 165 is accommodated in the installation cavity 143 and is arranged on the side of the angle measurement spectrometer 162 facing away from the angle measurement corner cone reflection prism 164, for detecting light energy.

[0030] The angle measurement spectrometer 162 reflects a portion of the output light from the angle measurement light source 161 onto one of the angle measurement conic reflection prisms 164. This portion of the output light is refracted by the angle measurement conic reflection prism 164 and then output in parallel. It passes through the angle measurement spectrometer 162 and is incident on the angle measurement photodetector 165. The angle measurement spectrometer 162 projects another portion of the output light from the angle measurement light source 161 along the optical path of the output light onto the angle measurement right-angle reflector 163. The angle measurement right-angle reflector 163 reflects the projected output light onto another angle measurement conic reflection prism 164. After being refracted by the corresponding angle measurement conic reflection prism 164, it is output in parallel and passes through the angle measurement right-angle reflector 163 and the angle measurement spectrometer 162 in sequence and is incident on the angle measurement photodetector 165.

[0031] In this embodiment, the angle measurement optical interferometer module 16 further includes two window mirrors 167 . Both window mirrors 167 are fixed within the mounting cavity 143 of the base 140 . One window mirror 167 is positioned between the angle measurement right-angle reflector 163 and the corresponding angle measurement retroreflector prism 164 , while the other window mirror 167 is positioned between the angle measurement beam splitter 162 and the corresponding angle measurement retroreflector prism 164 . Window mirrors 167 are typically made of glass or plastic lenses, such as PMMA (polymethyl methacrylate), and have excellent light transmittance. A transmissive film (not shown) may be applied to the window mirrors 167 .

[0032] Please see again Figure 1 The rotation angle measurement assembly 10 further includes a rotary drive member 17, which is connected to the base 140 of the rotating base 14 to drive the rotating base 14 to rotate about the first axis 50. In this embodiment, the rotary drive member 17 includes a driven gear 171, a rotary drive motor 172, and a worm gear 173. The driven gear 171 is fixed to the fixed base 12, and the central axis of the driven gear 171 is coaxial with the first axis 50. The rotary drive motor 172 is fixed to the base 140 of the rotating base 14 and connected to the worm gear 173, which meshes with the driven gear 171. During use, the rotary drive motor 172 drives the worm gear 173 to rotate. Since the driven gear 173 is fixed to the fixed base 12 and remains stationary, the rotation of the worm gear 173 can drive the rotary drive motor 172 and the rotating base 14 to rotate together.

[0033] Please also see Figure 2 、 Figure 5 and Figure 6 The displacement measuring assembly 20 includes a moving seat 21 and a displacement measuring optical interference module 23. The moving seat 21 is slidably mounted on the rotating seat 14. The displacement measuring optical interference module 23 is mounted on the rotating seat 14 and the moving seat 21 to measure the displacement of the moving seat 21 sliding relative to the rotating seat 14.

[0034] In this embodiment, the movable seat 21 is slidably mounted on the seat body 140 of the rotating seat 14 and is located on the side of the seat body 140 facing away from the driven gear 171. For details, please refer to Figure 4 A slideway 141 is provided on the side of the base 140 facing away from the worm gear 173, and a guide rail 211 is provided on the side of the movable base 21 facing the base 140. The slideway 141 slidably engages with the guide rail 211 to slidably connect the movable base 21 with the base 140 of the rotating base 14, with the movable base 21 slidingly connected in a direction perpendicular to the first axis 50. A third through hole 213 is defined approximately at the center of the movable base 21. One end of the third through hole 213 communicates with the end of the second through hole 142 facing away from the first through hole 120. A receiving groove 214 is defined within the movable base 21.

[0035] Please also see Figures 10 to 12 In this embodiment, the displacement measurement optical interference module 23 includes a displacement measurement light source 231, a displacement measurement spectroscope 232, a fixed reflector 233, a movable reflector 234 and a displacement measurement photoelectric detector 235. The displacement measurement light source 231, the displacement measurement spectroscope 232 and the fixed reflector 233 are all received in the receiving groove 214 and fixed on the movable base 21. The displacement measurement light source 231 is preferably a laser emitter, and the fixed reflector 233 is fixed on the rotating base 14. Specifically, the rotating base 14 also includes a mounting block 147, which is fixed to the base body. A fixing groove 215 is recessed on the side of the movable base 21 facing the rotating base 14. The movable base 21 is slidably connected to the mounting block 147 through the fixing groove 215. A light hole 216 is formed through the side wall of the fixing groove 215 facing the displacement measurement light source 231, through which a light beam passes. A fixed reflector 233 is received in the fixing groove 215 and fixedly connected to the mounting block 147. Specifically, a mounting groove (not shown) is recessed on one end of the mounting block 147 facing the displacement measurement light source 231, and the fixed reflector 233 is fixed in the mounting groove of the mounting block 147. The displacement measurement spectroscope 232 and the fixed reflector 233 are arranged in sequence along the direction of light emitted by the displacement measurement light source 231. The movable reflector 234 and the displacement measurement photodetector 235 are respectively disposed on opposite sides of the displacement measurement spectroscope 232. The displacement measurement photodetector 235 is used to detect light energy.

[0036] The displacement measuring spectrometer 232 reflects a portion of the output light of the displacement measuring light source 231 onto the movable reflector 234, which is then reflected by the movable reflector 234 and incident on the displacement measuring photodetector 235 through the displacement measuring spectrometer 232. The displacement measuring spectrometer 232 projects another portion of the output light of the displacement measuring light source 231 onto the fixed reflector 233, which is then reflected by the fixed reflector 233 and reflected by the displacement measuring spectrometer 232 and incident on the displacement measuring photodetector 235.

[0037] Please also see Figures 13 to 20 In this embodiment, the spindle rotation deviation measurement device based on optical interference also includes an optical path folding assembly 24 disposed on the outgoing optical path of the displacement measurement light source 231 and located between the displacement measurement beam splitter 232 and the fixed reflector 233. The optical path folding assembly 24 includes two reflector assemblies 240 spaced apart along the optical path of the outgoing light from the displacement measurement light source 231. The two reflector assemblies 240 are respectively fixed to the movable base 21 and the rotating base 14, forming a partition cavity 241 between the two reflector assemblies 240. In this embodiment, one reflector assembly 240 is fixed to the end surface of the mounting block 147 facing the displacement measurement light source 231; the other reflector assembly 240 is fixed to the movable base 21.

[0038] Each reflector assembly 240 includes two rows of first right-angle prisms 242, a parallelogram-shaped reflector 243, and a second right-angle prism 244. In each row of first right-angle prisms 242, several first right-angle prisms 242 are arranged along a first direction parallel to the length of the cavity 241. The first right-angle prisms 242 reflect light using two corresponding right-angled surfaces 245. The two rows of first right-angle prisms 242 in each reflector assembly 240 are distributed along a second direction perpendicular to both the first direction and the optical path of light emitted from the displacement measurement light source 231. Both right-angled surfaces 245 of the first right-angle prisms 242 are coated with a reflective film (not shown). The inclined surfaces 246 of the first right-angle prisms 242 of the two reflector groups 240 are opposite to each other, and the first right-angle prisms 242 of the two reflector groups 240 are staggered. In this embodiment, the two reflector groups 240 are symmetrical about the center point of the optical path folding device, and the right angle of the first right-angle prism 242 is opposite to the junction of two adjacent first right-angle prisms 242 in another row of first right-angle prisms 242.

[0039] A parallelogram reflector 243 is disposed between two adjacent first right-angle prisms 242 in a row of first right-angle prisms 242. In this embodiment, the parallelogram reflector 243 and the plurality of first right-angle prisms 242 in the corresponding row are located on the same plane. The parallelogram reflector 243 includes two parallel, opposing reflective surfaces 247 and two parallel, opposing incident and outgoing light surfaces 248. The two reflective surfaces 247 face the two adjacent first right-angle prisms 242 in the corresponding row, respectively. Both reflective surfaces 247 are coated with a reflective film (not shown). One of the incident and outgoing light surfaces 248 faces the other reflector assembly 240.

[0040] In this embodiment, each reflector group 240 includes a row of first right-angle prisms 242 with a parallelogram reflector 243, which includes six first right-angle prisms 242. The six first right-angle prisms 242 are evenly divided into two groups, and the parallelogram reflector 243 is disposed between the two groups of first right-angle prisms 242 in the corresponding row. Each reflector group 240 does not include a row of first right-angle prisms 242 with a parallelogram reflector 243, which includes seven first right-angle prisms 242.

[0041] A second rectangular prism 244 is disposed at one end of the corresponding reflector assembly 240. The second rectangular prism 244 and the first rectangular prism 242 are perpendicular to each other. The main cross-section of the second rectangular prism 244 faces the first rectangular prism 242 of the corresponding reflector assembly 240. The inclined surface 246 of the second rectangular prism 244 faces the inclined surface 246 of the first rectangular prism 242 of the other reflector assembly 240. The second rectangular prism 244 reflects light using its two corresponding rectangular surfaces 245, thereby reflecting light beams from one row of the first rectangular prisms 242 of the other reflector assembly 240 into another row of the first rectangular prisms 242 of the other reflector assembly 240. In this embodiment, both rectangular surfaces 245 of the second rectangular prism 244 are coated with a reflective film (not shown).

[0042] In this embodiment, the overall lengths of the two reflector assemblies 240 are substantially equal. When assembling the reflector assembly 240, the first rectangular prism 242, the parallelogram reflector 243, and the second rectangular prism 244 can be directly connected together using glue or the like, and then secured to the mounting block 147 or the movable base 21 using glue or the like. Alternatively, the first rectangular prism 242, the parallelogram reflector 243, and the second rectangular prism 244 of the reflector assembly 240 can be first secured to a fixing bracket, and then the fixing bracket can be secured to the mounting block 147 or the movable base 21 for easier installation.

[0043] The displacement measuring beam splitter 232 projects another part of the output light of the displacement measuring light source 231 onto the parallelogram reflector 243 of one of the reflector groups 240. The light beam is incident from the parallelogram reflector 243 of one of the reflector groups 240, is reflected by the first right-angle prism 242 and the second right-angle prism 244 of the two reflector groups 240, and then is emitted from the parallelogram reflector 243 of the other reflector group 240 to the fixed reflector 233. Similarly, the light beam reflected by the fixed reflector 233 is emitted from the fixed reflector 233 through the fixed reflector 233. Light is incident on the parallelogram reflector 243 of one of the reflector groups 240, is reflected by the first right-angle prism 242 and the second right-angle prism 244 of the two reflector groups 240, and then is emitted toward the displacement measurement beam splitter 232 through the parallelogram reflector 243 of the other reflector group 240. Specifically, it is assumed that the first right-angle prisms 242 in the row with the parallelogram reflector 243 are the first right-angle prisms in the first row, and the first right-angle prisms 242 in the row without the parallelogram reflector 243 are the first right-angle prisms in the second row.

[0044] The light beam is incident from the incident and outgoing surfaces 248 of the parallelogram reflector 243 in one of the reflector groups 240, is reflected by the two reflective surfaces 247 of the parallelogram reflector 243, and then is emitted from the other incident and outgoing surface 248 of the parallelogram reflector 243 to the first right-angle prism 242 in the first row of the first right-angle prisms in the other reflector group 240;

[0045] After entering the first right-angle prism 242, the light beam is reflected by the two right-angled surfaces 245 of the first right-angle prism 242 and then alternately reflected along optical path A by the first right-angle prisms 242 in the first row of the two reflector groups 240 until it reaches a second right-angle prism 244. The right-angled surface 245 of the second right-angle prism 244 then reflects the incident light beam along optical path B to the first right-angle prisms in the second row.

[0046] After the light beam enters the second row of first right-angle prisms 242, it is reflected by the two right-angled surfaces 245 of the second row of first right-angle prisms 242. It then alternately reflects along optical path C in a plurality of first right-angle prisms 242 in the second row of the two reflector groups 240 until it reaches another second right-angle prism 244. The right-angled surface 245 of the other second right-angle prism 244 reflects the incident light beam along optical path D to the first row of first right-angle prisms 242.

[0047] After the light beam enters the first row of first right-angle prisms 242, it is reflected by the two right-angle surfaces 245 of the first row of first right-angle prisms 242, and is alternately reflected along the optical path E in the plurality of first right-angle prisms 242 in the first row of the two reflector groups 240 until it reaches another parallelogram reflector 243; the light beam is incident from the incident and output surfaces 248 of the other parallelogram reflector 243, and after being reflected by the two reflective surfaces 247 of the parallelogram reflector 243 in sequence, it is emitted through the other incident and output surface 248 of the other parallelogram reflector 243.

[0048] Therefore, the incident light beam passes through all the first right-angle prisms 242 and the second right-angle prisms 244 of the two reflector groups 240 via the optical paths A, B, C, D, and E in sequence. During this process, the light beam is folded back (n+1) times in the spacing cavity 241, that is, the light beam passes through the spacing cavity 241 (n+1) times, where n is the sum of the number of the first right-angle prisms 242 and the second right-angle prisms 244 in the optical path folding component 24. In this embodiment, the light beam is folded back and forth 29 times in the spacer cavity 241. Furthermore, because a fixed reflector 233 is provided on the side of one of the reflector assemblies 240 facing away from the displacement measurement spectroscope 232, the light beam emitted from the optical path folding assembly 24 is reflected by the fixed reflector 233 and reenters the optical path folding assembly 24 for multiple reflections before finally being emitted from the optical path folding assembly 24. At this point, the light beam passes through the spacer cavity 241 2(n+1) times. In this embodiment, the light beam folds back and forth 58 times in the spacer cavity 241. Accordingly, if one of the reflector assemblies 240 is displaced by Δd relative to the other reflector assemblies 240, the optical path length of the light beam after passing through the optical path folding assembly 24 changes by 2(n+1)*Δd, meaning that the optical path length is 2(n+1) times the original displacement Δd.

[0049] Please see again Figure 1 The displacement measurement assembly 20 further includes a mobile drive mechanism 25, which is fixed to the rotating base 14 and connected to the mobile base 21 to drive the mobile base 21 to move linearly. In this embodiment, the mobile drive mechanism 25 includes a screw motor 251 and a screw 253. The screw motor 251 is fixed to the base 140 of the rotating base 14 and connected to the screw 253. The screw 253 is parallel to the sliding direction of the mobile base 21 and is threadedly connected to the mobile base 21. The screw motor 251 drives the screw 253 to rotate, thereby driving the mobile base 21 to move relative to the rotating base 14 through the screw 253.

[0050] Please also see Figure 2 、 Figure 3 、 Figure 5 and Figure 6The pitch angle measurement assembly 30 includes a pitch seat 31 and a pitch angle measurement optical interference module 34. The pitch seat 31 is rotatably mounted on the movable seat 21 and can swing relative to the movable seat 21 around a second axis 60. The second axis 60 is perpendicular to the first axis 50 and the sliding direction of the movable seat 21. The pitch angle measurement optical interference module 34 is mounted on the movable seat 21 and the pitch seat 31 to measure the swing angle of the pitch seat 31 relative to the movable seat 21.

[0051] In this embodiment, the pitch seat 31 includes a support 310, two fixed gears 313, two connecting frames 315 and two sliding racks 317. The support 310 is rotatably mounted on the moving seat 21. Figure 4 In this embodiment, the support 310 is rotatably connected to the movable base 21 via a connecting mechanism 32. Specifically, the connecting mechanism 32 includes two fixing ears 321 and a connecting shaft 323. The two fixing ears 321 are fixed to opposite sides of the movable base 21, and the opposite ends of the connecting shaft 323 are fixedly connected to the two fixing ears 321. The connecting shaft 323 is located on the second axis 60, and the support 310 is rotatably mounted on the connecting shaft 323. In this embodiment, a fourth through hole 311 is further defined approximately at the center of the support 310. The fourth through hole 311 extends through opposite sides of the support 310 along the first axis 50. One end of the fourth through hole 311 communicates with the end of the third through hole 213 facing away from the second through hole 213. A fixing cavity 312 is also defined within the support 310.

[0052] Two fixed gears 313 are fixed to opposite sides of the support 310 of the tilting seat 31. In this embodiment, the two fixed gears 313 are incomplete gears and are located on opposite sides of the connecting shaft 323 along the sliding direction of the movable seat 21. Two connecting frames 315 are fixedly connected to the movable seat 21. Two sliding racks 317 are slidably mounted on the two connecting frames 315 and respectively mesh with the two fixed gears 313. In this embodiment, the sliding direction of the sliding racks 317 is parallel to the first axis 50. When the support 310 is subjected to force to rotate about the second axis 60, the two sliding racks 317 are driven to slide by the two fixed gears 313.

[0053] In this embodiment, the pitch angle measurement optical interference module 34 is installed on the moving base 21 and the two sliding racks 317. Figure 10 and Figure 11 The pitch angle measurement light interference module 34 includes a pitch angle measurement light source 341, a pitch angle measurement beam splitter 342, a first right-angle reflector 343, a second right-angle reflector 344, a third right-angle reflector 345, a first corner cube prism 346 ( Figure 6 )、Second corner cube prism 347 ( Figure 6) and a pitch angle measurement photodetector 348. The pitch angle measurement light source 341, the pitch angle measurement beam splitter 342, the first right-angle reflector 343, the second right-angle reflector 344, the third right-angle reflector 345, and the pitch angle measurement photodetector 348 are all fixed to the movable base 21 and accommodated in the accommodation slot 214. The pitch angle measurement light source 341 is preferably a laser emitter. The pitch angle measurement beam splitter 342 is located on the optical path of the outgoing light of the pitch angle measurement light source 341. The first right-angle reflector 343 is disposed on one of the split light paths of the pitch angle measurement beam splitter 342. The second right-angle reflector 344 is disposed on one side of the first right-angle reflector 343. The third right-angle reflector 345 is disposed on the other split light path of the pitch angle measurement beam splitter 342. The pitch angle measurement photodetector 348 is disposed on the side of the pitch angle measurement beam splitter 342 facing away from the first right-angle reflector 343. The first corner cube prism 346 and the second corner cube prism 347 are respectively fixed on the two sliding racks 317 and are both located outside the receiving groove 214. An escape channel 217 for the light beam to enter and exit the receiving groove 214 is opened on the groove wall of the receiving groove 214 corresponding to the two sliding racks 317, so that the first corner cube prism 346 and the second corner cube prism 347 can receive the light beam from the receiving groove 214 and can reflect the received light beam into the receiving groove 214.

[0054] The pitch angle measurement spectroscope 342 reflects a portion of the light emitted by the pitch angle measurement light source 341 onto the first right-angle reflector 343. The light is then reflected by the first right-angle reflector 343 and the second right-angle reflector 344, incident on the first corner cube 346, reflected by the first corner cube 346, emitted in parallel, and sequentially passed through the second right-angle reflector 344, the first right-angle reflector 343, and the pitch angle measurement spectroscope 342 to be transmitted to the pitch angle measurement photodetector 348. The pitch angle measurement spectroscope 342 projects another portion of the light emitted by the displacement measurement light source 231 onto the third right-angle reflector 345. The light is then reflected by the third right-angle reflector 345, incident on the second corner cube 347, reflected by the second corner cube 347, emitted in parallel, and sequentially reflected by the third right-angle reflector 345 and the pitch angle measurement spectroscope 342 to be transmitted to the pitch angle measurement photodetector 348.

[0055] In this embodiment, the pitch angle measurement light interference module 34 also includes a fourth right-angle reflector 349, which is fixed on the movable base 21 and received in the receiving groove 214 of the movable base 21. The fourth right-angle reflector 349 is arranged between the pitch angle measurement light source 341 and the pitch angle measurement spectrometer 342, and is used to change the emission direction of the light beam of the pitch angle measurement light source 341, and then adjust the installation position of the pitch angle measurement light source 341, so that the installation position layout of each component of the pitch angle measurement light interference module 34 is more reasonable, so as to reduce the area required for the device.

[0056] Please see again Figure 3 The pitch angle measurement assembly 30 further includes a swing drive member 36, which is connected to the pitch seat 31 to drive the pitch seat 31 to swing about the second axis 60. In this embodiment, the swing drive member 36 includes a swing drive motor 361, a driving gear 363, and a passive gear 365. The swing drive motor 361 is fixed to the movable seat 21 and connected to the driving gear 363. The passive gear 365 is an incomplete gear. The passive gear 365 is fixed to the support 310 of the pitch seat 31 and is disposed on the same side as one of the sliding racks 317. The passive gear 365 meshes with the driving gear 363. The swing drive motor 361 drives the driving gear 363 to rotate. The rotating driving gear 363 drives the passive gear 365 to rotate, thereby driving the pitch seat 31 fixed to the passive gear 365 to swing about the second axis 60.

[0057] In this embodiment, the optical interference-based spindle rotation deviation measurement device is provided with a detection hole 70 through which the spindle 200 can move. The detection hole 70 extends through the fixed base 12, the rotating base 14, the movable base 21, and the pitch base 31. Specifically, the first through hole 120 of the fixed base 12, the second through hole 142 of the rotating base 14, the third through hole 213 of the movable base 21, and the fourth through hole 311 of the pitch base 31 collectively constitute the detection hole 70. A posture detection optical interference module 40 is mounted on the pitch base 31 to detect whether the rotation angle of the rotating base 14, the travel distance of the movable base 21, and the swing angle of the pitch base 31 are consistent with the spindle 200 deviation within the detection hole 70.

[0058] Please also see Figure 21 In this embodiment, the posture detection optical interference module 40 includes a position detection light source 41, a first beam splitter 42, a second beam splitter 43, a third beam splitter 44, a first reflector 45, a second reflector 46, a first photodetector 47, and a second photodetector 48, all of which are fixed to the support 310 of the pitch seat 31. The position detection light source 41 is preferably a laser emitter. The first beam splitter 42 is disposed on the optical path of the output light of the position detection light source 41. The second beam splitter 43 and the third beam splitter 44 are respectively disposed on the two split light paths of the first beam splitter 42. The first reflector 45 is located on the side of the second beam splitter 43 facing away from the first beam splitter 42. The second reflector 46 is located on the side of the third beam splitter 44 facing away from the first beam splitter 42. The first photodetector 47 is disposed on the side of the second beam splitter 43 facing away from the detection hole 70, and the second photodetector 48 is disposed on the side of the third beam splitter 44 facing away from the detection hole 70.

[0059] The first beam splitter 42 splits the light emitted by the position detection light source 41 into a first beam and a second beam, wherein:

[0060] The first beam splitter 42 reflects the first light beam onto the second beam splitter 43. The second beam splitter 43 splits the first light beam into a first light beam A and a first light beam B. The second beam splitter 43 projects the first light beam A onto the first reflector 45. The first reflector 45 then reflects the first light beam onto the second beam splitter 43. The second beam splitter 43 reflects a portion of the second light beam A onto the first photodetector 47. The second beam splitter 43 reflects the first light beam B onto the spindle 200 in the detection hole 70. The spindle 200 reflects the first light beam B onto the second beam splitter 43. The second beam splitter 43 projects a portion of the first light beam B onto the first photodetector 47.

[0061] The first beam splitter 42 projects the second light beam onto the third beam splitter 44, which splits the second light beam into a second light beam A and a second light beam B. The third beam splitter 44 projects the second light beam A onto the second reflector 46, where it is reflected back onto the third beam splitter 44. The third beam splitter 44 reflects a portion of the second light beam A onto the second photodetector 48. The third beam splitter 44 reflects the second light beam B onto the spindle 200 in the detection hole 70. The spindle 200 reflects the second light beam B back onto the third beam splitter 44 (because the spindle 200 is typically made of metal and has a relatively smooth surface, its reflectivity to light meets the requirements for generating optical interference fringes). A portion of the second light beam B passes through the third beam splitter 44 and is projected onto the second photodetector 48. The first photodetector 47 and the second photodetector 48 are both used to detect light energy.

[0062] In this embodiment, the posture detection optical interference module 40 further includes two cylindrical mirrors 491. Both cylindrical mirrors 491 are fixed to the support 310 of the pitch mount 31. One cylindrical mirror 491 is positioned between the second beam splitter 43 and the detection aperture 70, and the other cylindrical mirror 491 is positioned between the third beam splitter 44 and the detection aperture 70. The cylindrical mirrors 491 are used to converge the first light beam B and the second light beam B onto the principal axis 200 of the detection aperture 70. The convergence points of the first light beam B and the second light beam B are both located at the center of the fourth through hole 311, thereby ensuring that the first photodetector 47 and the second photodetector 48 can detect interference fringes.

[0063] In this embodiment, the posture detection optical interference module 40 also includes two optical compensation mirrors 492 fixed to the support 310 of the pitch seat 31, one of which is located between the first reflector 45 and the second beam splitter 43, and the other is located between the second reflector 46 and the third beam splitter 44. The provision of the optical compensation mirrors 492 ensures that the energy of the light beams reaching the first photodetector 47 and the second photodetector 48 for forming interference fringes is close, thereby ensuring the formation of clear interference fringes. In this embodiment, the posture detection optical interference module 40 is fixed in an outer cover 400, which is fixed to the support 310 of the pitch seat 31. The posture detection optical interference module 40 is fixedly connected to the pitch seat 31 via the outer cover 400. By fixing the posture detection optical interference module 40 to the outer cover 400, the installation of the posture detection optical interference module 40 is more convenient.

[0064] In this embodiment, two groups of posture detection optical interference modules 40 are provided. The two groups of posture detection optical interference modules 40 are spaced apart around the detection hole 70, and the two groups of posture detection optical interference modules 40 can also be spaced apart along the first axis 50. The two groups of posture detection optical interference modules 40 can respectively detect different points on the main shaft 200 within the detection hole 70. Based on the detection results of multiple points, it is determined whether the rotation angle of the rotating seat 14, the movement distance of the moving seat 21, and the pitch angle of the pitch seat 31 are consistent with the deviation of the main shaft 200 within the detection hole 70, which can make the judgment result more accurate. It is understood that the posture detection optical interference modules 40 can also be provided as one or more groups as needed.

[0065] In this embodiment, the angle measurement optical interference module 16, the displacement measurement optical interference module 23, and the pitch angle measurement optical interference module 34 all adopt the Michael optical interferometer principle. The angle measurement photodetector 165, the displacement measurement photodetector 235, the pitch angle measurement photodetector 348, the first photodetector 47, and the second photodetector 48 are all CCD image sensors, which can convert the detected light radiation into electrical quantity. When in use, the output signal of the CCD image sensor is connected to an oscilloscope, an image display, or other signal storage device, so that the signal detected by the CCD image sensor can be reproduced to obtain an energy distribution diagram of the light. The structure of the CCD image sensor belongs to the prior art and will not be described here for the sake of space. Specifically, when using the spindle rotation deviation measurement device based on optical interference to detect the deviation of the spindle 200, the steps are roughly as follows:

[0066] S1, insert the main shaft 200 into the detection hole 70, and fix the fixing base 12 to the external bracket by bolts or other connecting parts;

[0067] S2, turn on the angle measurement light source 161, the displacement measurement light source 231, the pitch angle measurement light source 341 and the position detection light source 41, and adjust the spindle rotation deviation measuring device based on optical interference to the initial position by rotating the rotating seat 14, moving the moving seat 21 or swinging the pitch seat 31. At the initial position, the centers of the first through hole 120, the second through hole 142, the third through hole 213 and the fourth through hole 311 are all located on the first axis 50, and the first axis 50 is located on the central axis of the spindle 200, that is, on the Z axis of the machine tool, and the rotating seat 14, the movable seat 21 and the pitch seat 31 are all located in a plane perpendicular to the central axis of the spindle 200, that is, on the machining plane where the X axis and Y axis of the machine tool are located. During this process, by observing the light energy distribution diagram detected by the first photodetector 47 and the second photodetector 48 through the CCD camera, it can be determined whether the spindle rotation deviation measurement device based on optical interference is adjusted in place: Specifically, according to the principle of optical interference, when the light energy distribution detected by the first photodetector 47 and the second photodetector 48 is uniform, it means that the centers of the first through hole 120, the second through hole 142, the third through hole 213 and the fourth through hole 311 are all located on the central axis of the spindle 200, and the position of the spindle rotation deviation measurement device based on optical interference is adjusted in place; Figure 22 As shown, Figure 22 (a) is the light energy distribution diagram detected by the first photodetector 47, Figure 22 (b) is a diagram of the light energy distribution detected by the second photodetector 48. When the light energies detected by the first photodetector 47 and the second photodetector 48 are uniformly distributed, it indicates that the position of the spindle 200 rotation deviation measurement device based on optical interference is adjusted to the correct position.

[0068] S3, the workpiece to be processed is mounted on the end face of the spindle 200 of the machine tool, the machine tool is turned on, and the spindle 200 is rotated at the required speed to process the workpiece. During this process, when the spindle 200 deviates from the rotation due to the weight of the workpiece or other factors, the light energy distribution diagram detected by the first photodetector 47 and the second photodetector 48 changes and is no longer uniformly distributed, for example Figure 23 As shown, it is a diagram of the light energy distribution detected by the first photodetector 47 and the second photodetector 48 when the spindle 200 deviates from the X-axis and the Y-axis of the machine tool by an angle of 0.0001°:

[0069] S4, rotate the rotating base 14, observe the light energy distribution diagrams detected by the first photodetector 47 and the second photodetector 48, when the light energy distribution diagram stripes of the first photodetector 47 are symmetrical on the left and right, and at the same time, the light energy distribution diagram stripes of the second photodetector 48 are close to vertical, the rotating base 14 is rotated and adjusted into place, such as Figure 24As shown, at this time, the rotation angle of the rotating seat 14 is consistent with the rotation angle of the measuring point on the spindle 200 on the machine tool processing plane (that is, the plane where the machine tool X-axis and Y-axis are located) around the machine tool Z-axis. In this embodiment, the measuring point is the intersection G of the first light beam B, the second light beam B and the central axis of the spindle 200, as shown in FIG. Figure 21 As shown; in this process, the rotational motion of the rotating base 14 is converted into the linear movement of the two moving racks 146 through the cooperation of the follower gear 145 and the two moving racks 146. Since the two angle measurement corner reflectors 164 of the angle measurement optical interference module 16 are respectively fixed to the same end of the two moving racks 146, the two angle measurement corner reflectors 164 move the same distance d1 as the moving racks 146. d1 is the parameter required to calculate the rotation angle of the rotating base 14;

[0070] S5, swing the pitch seat 31, observe the light energy distribution diagrams detected by the first photodetector 47 and the second photodetector 48, when the light energy distribution diagram of the first photodetector 47 is symmetrical left and right and symmetrical up and down, and the stripes are vertical, at the same time, the light energy distribution diagram of the second photodetector 48 is vertical, as shown in FIG. Figure 25 As shown, the pitch base 31 is swung and adjusted into position. At this time, the swing angle of the pitch base 31 is consistent with the swing angle of the central axis of the spindle 200 relative to the Z-axis of the machine tool. During this process, the two fixed gears 313 and the two sliding racks 317 cooperate to convert the swing of the pitch base 311 into linear sliding of the two sliding racks 317. Since the first corner cube 346 and the second corner cube 347 of the pitch angle measurement optical interferometer module 34 are fixed to the two sliding racks 317, the first corner cube 346 and the second corner cube 347 move with the sliding of the two sliding racks 317. The first corner cube 346 and the second corner cube 347 move the same distance. Let the distance moved by the first corner cube 346 and the second corner cube 347 be d2, which is the parameter required for calculating the swing angle of the pitch base 31.

[0071] S6, move the movable base 21, observe the light energy distribution diagrams detected by the first photodetector 47 and the second photodetector 48, when the light energy distribution diagrams of the first photodetector 47 and the second photodetector 48 are both in a uniform distribution state again ( Figure 26 As shown, the movable base 21 is adjusted into position, and the first axis 50 is once again located on the central axis of the spindle 200. During this process, the fixed reflector 233 is fixed to the rotating base 14 and remains stationary, while the movable reflector 234 is fixed to the movable base 21 and moves linearly with the movable base 21. Assume that the movement of the movable reflector 234 relative to the fixed reflector 233 is d3, where d3 is the radial runout displacement of the spindle 200.

[0072] Through the above steps S1 to S6 , the spindle rotation deviation measuring device based on optical interference can be adjusted from the initial position to a consistent posture of the spindle 200 after the rotation deviation.

[0073] The deviation value of the main shaft 200 rotation is calculated as follows:

[0074] During the adjustment process in step S4, the energy distribution image of the light detected by the angle measurement photodetector 165 is observed to determine the relative displacement d1 of the two angle measurement corner reflectors 164 during the adjustment of the rotating base 14. Specifically, in this embodiment, the relative displacement d1 of the two angle measurement corner reflectors 164 is determined by observing the number of alternating light and dark intensity patterns in the energy distribution image of the light detected by the angle measurement photodetector 165. For example, when the brightness of the light energy distribution image changes once, from bright to dark, it indicates that the two angle measurement retroreflectors 164 have moved relative to each other by 1 / 4 wavelength. If the brightness changes again, from dark to bright, the two angle measurement retroreflectors 164 have moved relative to each other by another 1 / 4 wavelength. The process from bright to dark to bright indicates that the two angle measurement retroreflectors 164 have moved relative to each other by 1 / 2 wavelength. Assuming the number of light intensity alternations between bright and dark in the light energy distribution image is N1, the relative movement distance d1 of the two angle measurement retroreflectors 164 is N1λ1 / 4, where λ1 is the wavelength of the incident light emitted by the angle measurement light source 161 and N1 is the number of light intensity alternations in the light energy distribution image detected by the angle measurement photodetector 165. Therefore, the relative displacement d1 of the two angle measurement retroreflectors 164 can be obtained based on the number of light intensity alternations in the light energy distribution image detected by the angle measurement photodetector 165.

[0075] See Figure 27, assuming that the position of any point on the follower gear 145 before the rotating base 14 rotates is D1, and the rotating base 14 rotates to the position around the first axis 50, that is, the center of the first through hole 120, the rotating base 14 rotates by an angle of α. At this time, the position of the point on the follower gear 145 is D2, and the arc length from the position D1 to D2 is L1. The arc length L1 is the distance traveled by the point after the rotating base 14 rotates by an angle of α. Since the rotational motion of the rotating base 14 is converted into the linear movement of the two moving racks 146, the linear movement distance of the moving rack 146 is equal to the distance traveled by the point on the rotating base 14. Equally, that is, the value of the arc length L1 is equal to the value of 2d1. According to the arc length calculation formula L1 = απR / 180, because the arc length L1 value is equal to the value of 2d1, that is, d1 = απR / 90, R is the distance from the center O1 of the first through hole 120 to the position D1, which can be obtained from the manufacturing parameters of the spindle rotation deviation measurement device based on optical interference. Therefore, after obtaining the value d1, the rotation angle α of the rotating seat 14 can be calculated by the arc length calculation formula, and the rotation angle α of the rotating seat 14 is equal to the angle of rotation of the measuring point G on the spindle 200 on the working surface of the machine tool around the Z axis of the machine tool.

[0076] Similarly, during the adjustment process in step S5, the relative displacement d2 of first corner cube 346 and second corner cube 347 is calculated by observing the number of bright and dark intensity alternations in the light energy distribution image detected by pitch angle measurement photodetector 348. d2 = N2λ2 / 4, where λ2 is the wavelength of the incident light emitted by pitch angle measurement light source 341, and N2 is the number of bright and dark alternations in the light energy distribution image detected by pitch angle measurement photodetector 348 during the oscillation of pitch mount 31.

[0077] See Figure 28 Assume that the position of a certain point on the fixed gear 313 of the pitch seat 31 before the pitch seat 31 rotates is E1, and the pitch seat 31 rotates to the desired position around the second axis 60. The angle of rotation of the pitch seat 31 is β. At this time, the position of the point on the fixed gear 313 of the pitch seat 31 is E2. The path traveled by the point from E1 to E2 is arc length L2. Since the rotational motion of the pitch seat 31 is converted into the linear motion of the sliding rack 313, the linear motion distance of the sliding rack 313 is equal to the path traveled by the point on the pitch seat 31, that is, arc length L2. The value of is equal to the value of 2d2. According to the arc length calculation formula L2 = βπr / 180, because the arc length L2 value is equal to the value of 2d2, that is, d2 = βπr / 90, r is the length from the center O2 of the connecting shaft 323 to the point E1, which can be obtained from the manufacturing parameters of the spindle rotation deviation measurement device based on optical interference. Therefore, after obtaining the value d2, the rotation angle β of the rotating seat 14 can be calculated by the arc length calculation formula, and the rotation angle β of the rotating seat 14 is equal to the swing deflection angle of the spindle 200 relative to the processing plane.

[0078] During the adjustment process in step S6, the displacement d3 of the movable reflector 234 relative to the fixed reflector 233 is obtained by observing the number of alternating light and dark intensity or the movement of stripes in the light energy distribution image detected by the displacement measurement photodetector 235. Specifically, in this embodiment, the movable reflector 234 and the fixed reflector 233 are perpendicular to each other. At this time, the light energy is uniform on the entire CCD image sensor. The relative movement of the movable reflector 234 and the fixed reflector 233 produces alternating changes in light intensity on the entire surface of the CCD, that is, the entire surface changes from bright to dark and then from dark to bright. Therefore, in this embodiment, the displacement d3 of the movable reflector 234 relative to the fixed reflector 233 is obtained by observing the number of alternating light and dark intensity in the light energy distribution image detected by the displacement measurement photodetector 235. d3=N3λ3 / 4, where λ1 is the wavelength of the incident light emitted by the displacement measurement light source 231, and N3 is the number of alternating light and dark intensity in the light energy distribution image during the movement of the movable reflector 234 relative to the fixed reflector 233. It is understood that the movable reflector 234 and the fixed reflector 233 may not be perpendicular to each other. In this case, the light energy will generate straight interference fringes on the entire CCD image sensor. The relative movement of the movable reflector 234 and the fixed reflector 233 will generate the movement of interference fringes on the entire surface of the CCD. In this case, the displacement d3 of the movable reflector 234 relative to the fixed reflector 233 can be obtained by observing the movement of the fringes in the light energy distribution image detected by the angle measurement photodetector 165. d3 = N3 ’ λ3 / 2, N3 ’ It is the amount of left-right movement of the interference fringes in the energy distribution image of light during the movement of the movable reflector 234 relative to the fixed reflector 233.

[0079] In this embodiment, since an optical path folding component 24 is provided, the movable reflector 234 moves together with one of the reflector groups 240, and the distance that the movable reflector 234 moves relative to the fixed reflector 233 is equal to the distance Δd that the two reflector groups 240 move relative to each other. Therefore, when the movable reflector 234 moves a distance d3 relative to the fixed reflector 233, d3=2(n+1)*Δd, and the actual displacement distance of the movable reflector 234 relative to the fixed reflector 233 is Δd=d3 / 2(n+1).

[0080] In addition, research has found that in step S4, when the main shaft 200 deflects in different directions, the deflection of the stripes in the light energy distribution image detected by the angle measurement photodetector 165 during the rotation of the rotating base 14 is also different. Therefore, during the rotation of the rotating base 14, the deflection direction of the main shaft 200 can be determined by observing the deflection of the stripes in the light energy distribution image detected by the angle measurement photodetector 165.

[0081] The optical interference-based spindle rotation deviation measurement device of this embodiment decomposes the deviation of the instantaneous rotation centerline of the spindle from the ideal rotation centerline during spindle rotation into the azimuth angle generated by the rotation of the measurement point G on the spindle on the machine tool work surface around the machine tool Z-axis, the radial displacement of the measurement point G on the spindle, and the swing angle of the instantaneous rotation centerline of the spindle relative to the machine tool Z-axis. During use, a dynamic measurement method is used to perform measurements at the actual operating speed of the spindle 200. When the spindle 200 rotates, the deviation of the spindle 200 is simulated by the rotation of the rotating seat 14, the movement of the moving seat 21, and the swing of the pitching seat 31. During this process, the posture detection optical interference module 40 can determine whether the rotation angle of the rotating seat 14, the movement distance of the moving seat 21, and the pitch angle of the pitching seat 31 are consistent with the deviation of the spindle 200. If consistent, it indicates that the posture of the spindle 200 rotation deviation measurement device is consistent with the posture of the spindle 200 after the rotation deviation. During the rotation of the rotating seat 14, the movement of the movable seat 21 and the swing of the pitch seat 31, the rotation angle of the rotating seat 14, the moving distance of the movable seat 21 and the pitch angle of the pitch seat 31 can be measured simultaneously by the angle measurement optical interference module 16, the displacement measurement optical interference module 23 and the pitch angle measurement optical interference module 34. The moving distance corresponds to the radial runout generated when the main shaft 200 rotates, the rotation angle corresponds to the azimuth angle generated by the rotation of the measuring point G on the main shaft around the Z axis of the machine tool on the working surface of the machine tool, and the pitch angle corresponds to the swing angle of the instantaneous rotation center line of the main shaft relative to the Z axis of the machine tool. Since the spindle rotation deviation measuring device based on optical interference uses the angle measuring optical interference module 16, the displacement measuring optical interference module 23, the pitch angle measuring optical interference module 34 and the posture detection optical interference module 40 to test the rotation deviation of the spindle 200, its accuracy is related to the wavelength of the light source used in the optical interference, and the accuracy can reach the nanometer level. At the same time, the angle measuring optical interference module 16, the displacement measuring optical interference module 23, the pitch angle measuring optical interference module 34 and the posture detection optical interference module 40 are all installed on the spindle rotation deviation measuring device based on optical interference without contacting the spindle 200, and are not affected by the vibration generated when the spindle 200 rotates. The measurement accuracy is improved and can meet the needs of high-precision machine tools.

[0082] Chinese invention patent application CN106425691A discloses a precision spindle rotation accuracy detection device and method based on the principle of laser interference. The precision spindle rotation accuracy detection optical path includes a box for installing the required instruments, a laser emitter installed in the box, four optical convex lenses, a semi-transparent and semi-reflective mirror, a reference ball and a CCD camera. Part of the laser beam will be emitted from the circular hole on the square box and hit the target ball, which is installed on the precision spindle through an extension rod. The analysis principle analyzes the laser interference pattern collected by the CCD camera to obtain the speed and three-dimensional displacement error of the precision spindle. The present invention is convenient for engineering detection and does not require error separation. It can simultaneously detect the speed, axial and radial displacement errors of the precision spindle, and the measurement accuracy reaches the nanometer level. However, it still has the following defects in actual use: (1) Since it needs to calculate the optical path difference, which is difficult to calculate, it is necessary to install a target ball at the end of the spindle, calculate the optical path difference based on the special shape of the target ball, and then obtain the speed, axial and radial displacement errors of the precision spindle based on the calculated optical path difference. It can only install a target ball at the end of the spindle, and cannot install other non-spherical irregular components, otherwise it is difficult to calculate the optical path difference. Therefore, it cannot detect the deviation of the spindle rotation when the actual part to be processed is installed at the end of the spindle. Its detection result may be significantly different from the actual use and the ideal state, resulting in reduced measurement accuracy. (2) The Chinese invention patent application CN106425691A adopts a fixed interference test system, and obtains the deviation of the spindle by calculating the optical path difference between the incident light and the reflected light of the laser transmitter. However, the calculation conditions of the optical path difference are harsh. It needs to be estimated under the premise that the spindle displacement is very small relative to the radius of the target ball and the angle between the incident light and the reflected light can be ignored. The optical path difference error obtained by the calculation is large, and as the spindle displacement increases, the optical path difference error obtained by the calculation will become larger, resulting in a small displacement range that can be measured. If the measurement range is exceeded, the device and algorithm will be invalid.

[0083] The spindle rotation deviation measurement device based on optical interference in an embodiment of the present invention adopts a method in which the spindle rotation deviation measurement device based on optical interference follows the movement of the spindle to perform measurement. When the device is consistent with the deviation posture of the spindle, the deviation of the device can be measured by the angle measurement optical interference module 16, the displacement measurement optical interference module 23, and the pitch angle measurement optical interference module 34 provided on the device, thereby obtaining the deviation of the spindle 200. Specifically, for the calculation of the rotation angle of the rotating seat 14, this embodiment converts the rotation motion of the rotating seat 14 into a rotation angle of the rotating seat 14 by cooperating with the follower gear 145 and the two moving racks 146. The linear movement of the two moving racks 146 fixes the angle measuring conic reflective prism 164 of the angle measuring optical interference module 16 on the moving rack 146. Therefore, the distance moved by the angle measuring conic reflective prism 164 can be conveniently measured by the angle measuring optical interference module 16, and then the rotation angle of the rotating seat 14 is calculated based on the measured distance moved by the angle measuring conic reflective prism 164. For the calculation of the movement displacement of the moving seat 21, the fixed reflector 233 of the displacement measuring optical interference module 23 is fixed on the rotating seat 14, and the moving reflector 234 is fixed on the moving seat 21 and moves with the moving seat 21. At this time, the moving reflector The distance that the mirror 234 moves relative to the fixed reflector 233 is the parameter required by the displacement measurement optical interference module 23 to calculate the radial displacement. For the calculation of the pitch angle of the pitch seat 31, this embodiment converts the swing of the pitch seat 31 into the linear sliding of the two sliding racks 317 through the cooperation of the two fixed gears 313 and the two sliding racks 317. The first corner cube 346 and the second corner cube 347 of the pitch angle measurement optical interference module 34 are respectively fixed on the two sliding racks 317. Therefore, the distance moved by the first corner cube 346 and the second corner cube 347 can be conveniently measured by the pitch angle measurement optical interference module 34, and then the distance measured can be calculated based on the measured distance. The rotation angle of the pitch seat 31 is calculated by measuring the distance moved by the first corner cube prism 346 or the second corner cube prism 347. This embodiment eliminates the need for calculating optical path difference and the need for a target sphere, allowing the actual processing components to be installed on the end face of the spindle 200 as needed. This allows for measurements that better reflect the actual processing conditions of the spindle 200 and provide higher measurement accuracy. Furthermore, the absence of optical path difference calculation avoids the complex optical path difference calculation that requires the use of a standard sphere, target sphere, and other components, leading to demanding measurement conditions. This prevents errors in the precision measurement of the spindle 200 caused by processes such as optical path difference estimation. In addition to ensuring measurement accuracy, it also allows for measurement of large deviations of the spindle 200. Furthermore, this embodiment directly measures the radial displacement and deflection angle of the spindle 200 using the rotation angle measurement optical interferometer module 16, the displacement measurement optical interferometer module 23, and the pitch angle measurement optical interferometer module 34. This provides more accurate measurement results than methods that obtain radial displacement errors of the spindle 200 by projecting the target sphere's center motion trajectory.

[0084] The optical interference-based spindle rotation deviation measurement device of an embodiment of the present invention also includes an optical path folding assembly 24. After entering the optical path folding assembly 24, the light beam can be reflected multiple times between two reflective mirror groups 240 before being emitted. This increases the optical path change, which is 2(n+1) times the actual displacement Δd. This can improve the sensitivity of displacement detection and further enhance the accuracy of displacement measurement. In addition, the two reflective mirror groups 240, through the provision of parallelogram reflectors 243, can make the outgoing light emitted from the optical path folding assembly 24 parallel to the incident light entering the optical path folding assembly 24, thereby facilitating optical path adjustment and subsequent displacement calculation.

[0085] It is understood that the rotating base 14, the moving base 21, and the pitching base 31 can also be driven manually. It is understood that the optical interference-based spindle 200 rotation deviation measurement device of this embodiment can be used to measure the rotation accuracy of the spindle 200 of a machine tool, such as a lathe or grinder. It is understood that the structure of the rotating drive member 17, the moving drive mechanism 25, and the swinging drive member 36 is not limited to this embodiment, and other drive devices of the prior art can also be used. It is understood that the number of the first right-angle prisms 242 is not limited to this embodiment, and it can also be set to other numbers as needed.

[0086] The above description is a detailed description of the preferred embodiments of the present invention, but the embodiments are not intended to limit the scope of the patent application of the present invention. Any equivalent changes or modifications completed under the technical spirit suggested by the present invention should fall within the patent scope covered by the present invention.

Claims

1. A spindle rotation deviation measurement device based on optical interference, characterized in that: include: A rotation angle measurement assembly (10) comprises a fixed seat (12), a rotating seat (14) and a rotation angle measurement light interference module (16); the rotating seat (14) is rotatably connected to the fixed seat (12) and is capable of rotating relative to the fixed seat (12) around a first axis (50); the rotation angle measurement light interference module (16) is mounted on the rotating seat (14) to measure the rotation angle of the rotating seat (14); A displacement measuring assembly (20) includes a moving seat (21) and a displacement measuring light interference module (23), wherein the moving seat (21) is slidably mounted on the rotating seat (14), and the displacement measuring light interference module (23) is mounted on the rotating seat (14) and the moving seat (21) to measure the displacement of the moving seat (21) sliding relative to the rotating seat (14); A pitch angle measuring assembly (30) includes a pitch seat (31) and a pitch angle measuring optical interference module (34), wherein the pitch seat (31) is rotatably mounted on the movable seat (21) and is capable of swinging relative to the movable seat (21) about a second axis (60), wherein the second axis (60) is perpendicular to the first axis (50) and the sliding direction of the movable seat (21), and the pitch angle measuring optical interference module (34) is mounted on the movable seat (21) and the pitch seat (31) to measure the swing angle of the pitch seat (31) relative to the movable seat (21); and The posture detection optical interference module (40) is installed on the pitch seat (31) and is used to detect whether the rotation angle of the rotating seat (14), the sliding displacement of the moving seat (21) and the swing angle of the pitch seat (31) are consistent with the deviation of the main axis (200).

2. The spindle rotation deviation measuring device based on optical interference according to claim 1, characterized in that: The rotating seat (14) includes a seat body (140), a follower gear (145) and two movable racks (146). The seat body (140) is rotatably connected to the fixed seat (12). The follower gear (145) is fixed on the seat body (140). The central axis of the follower gear (145) is coaxial with the first axis (50). The two movable racks (146) are both slidably mounted on the seat body (140) and respectively mesh with opposite sides of the follower gear (145). The rotation angle measurement optical interference module (16) is mounted on the seat body (140) and the two movable racks (146).

3. The spindle rotation deviation measuring device based on optical interference according to claim 2, characterized in that: The angle measurement light interference module (16) includes an angle measurement light source (161), an angle measurement spectroscope (162), an angle measurement right-angle reflector (163), two angle measurement cone reflectors (164) and an angle measurement photoelectric detector (165). The angle measurement light source (161), the angle measurement spectroscope (162) and the angle measurement right-angle reflector (163) are all fixed on the base (140). 2) Installed on the outgoing light path of the angle measurement light source (161), the angle measurement right-angle reflector (163) is located on the side of the angle measurement spectroscope (162) facing away from the angle measurement light source (161), two angle measurement conical reflectors (164) are respectively fixed on two movable racks (146), and the angle measurement photoelectric detector (165) is located on the side of the angle measurement spectroscope (162) facing away from the angle measurement conical reflectors (164); The angle measurement spectroscope (162) reflects a portion of the emitted light from the angle measurement light source (161) onto one of the angle measurement conical reflection prisms (164), and the light is refracted by the angle measurement conical reflection prism (164) and then emitted in parallel and passes through the angle measurement spectroscope (162) again to be incident on the angle measurement photoelectric detector (165); The angle measurement spectroscope (162) projects another part of the light emitted by the angle measurement light source (161) onto the angle measurement right-angle reflector (163), and the angle measurement right-angle reflector (163) reflects the projected light onto another angle measurement corner cone reflector prism (164). The light is refracted by the corresponding angle measurement corner cone reflector prism (164) and then emitted in parallel. The light passes through the angle measurement right-angle reflector (163) and the angle measurement spectroscope (162) in sequence and is incident on the angle measurement photoelectric detector (165).

4. The spindle rotation deviation measuring device based on optical interference according to claim 1, characterized in that: The displacement measurement light interference module (23) includes a displacement measurement light source (231), a displacement measurement spectroscope (232), a movable reflector (234), a fixed reflector (233) and a displacement measurement photoelectric detector (235). The displacement measurement light source (231), the displacement measurement spectroscope (232) and the movable reflector (234) are all fixed on the movable seat (21), the fixed reflector (233) is fixed on the rotating seat (14), the displacement measurement spectroscope (232) and the fixed reflector (233) are sequentially arranged on the optical path of the light emitted by the displacement measurement light source (231), and the movable reflector (234) and the displacement measurement photoelectric detector (235) are respectively arranged on opposite sides of the displacement measurement spectroscope (232); The displacement measurement spectroscope (232) reflects a portion of the output light of the displacement measurement light source (231) onto the movable reflector (234), and after being reflected by the movable reflector (234), the light passes through the displacement measurement spectroscope (232) and is incident on the displacement measurement photoelectric detector (235); The displacement measuring spectroscope (232) projects another portion of the outgoing light of the displacement measuring light source (231) onto the fixed reflector (233) along the optical path of the outgoing light of the displacement measuring light source (231), and after being reflected by the fixed reflector (233), the light is reflected by the displacement measuring spectroscope (232) onto the displacement measuring photoelectric detector (235).

5. The spindle rotation deviation measuring device based on optical interference according to claim 4, characterized in that: The spindle rotation deviation measurement device based on optical interference also includes an optical path folding component (24) disposed on the optical path of the light emitted by the displacement measurement light source (231) and located between the displacement measurement spectroscope (232) and the fixed reflector (233), the optical path folding component (24) including two reflector groups (240) relatively spaced apart along the optical path of the light emitted by the displacement measurement light source (231), the two reflector groups (240) being fixed on the movable seat (21) and the rotating seat (14), respectively, and forming a spacer cavity (241) between the two reflector groups (240); Each reflector set (240) includes two rows of first right-angle prisms (242), a parallelogram reflector (243) and a second right-angle prism (244); A plurality of first right-angle prisms (242) in each row of first right-angle prisms (242) are arranged along a first direction, the first direction being parallel to the length direction of the spacer cavity (241), and the first right-angle prisms (242) use two corresponding right-angle surfaces to reflect light; two rows of first right-angle prisms (242) in each reflector group (240) are arranged along a second direction perpendicular to both the first direction and the optical path direction of the light emitted by the displacement measurement light source (231); the oblique surfaces of the first right-angle prisms (242) of the two reflector groups (240) are opposite to each other, and the first right-angle prisms (242) of the two reflector groups (240) are staggered; The parallelogram reflector (243) is arranged between two adjacent first right-angle prisms (242) in one row of first right-angle prisms (242); The second right-angle prism (244) is arranged at one end of the corresponding reflector group (240), and the second right-angle prism (244) and the first right-angle prism (242) are perpendicular to each other, the main cross-section of the second right-angle prism (244) faces the first right-angle prism (242) of the corresponding group, and the second right-angle prism (244) uses two corresponding right-angle surfaces to reflect light; the inclined surface of the second right-angle prism (244) of each reflector group (240) is opposite to the inclined surfaces of the two rows of first right-angle prisms (242) at the corresponding end of the other reflector group (240), and the second right-angle prisms (244) of the two reflector groups (240) are respectively located at opposite ends of the light path folding component (24); The outgoing light of the displacement measurement light source (231) is incident through the parallelogram reflector (243) of one of the reflector groups (240), is reflected by a plurality of first right-angle prisms (242) and second right-angle prisms (244) of the two reflector groups (240), and then is emitted through the parallelogram reflector (243) of the other reflector group (240).

6. The spindle rotation deviation measuring device based on optical interference according to claim 1, characterized in that: The pitch seat (31) includes a support (310), two fixed gears (313), two connecting frames (315) and two sliding racks (317). The support (310) is rotatably mounted on the movable seat (21). The two fixed gears (313) are respectively fixed on opposite sides of the support (310). The two connecting frames (315) are respectively fixedly connected to the movable seat (21). The two sliding racks (317) are respectively slidably mounted on the two connecting frames (315) and respectively mesh with the two fixed gears (313). The support (310) is subjected to force to rotate around the second axis (60), and the two sliding racks (317) are respectively driven to slide by the two fixed gears (313). The pitch angle measurement optical interference module (34) is mounted on the movable seat (21) and the two sliding racks (317).

7. The spindle rotation deviation measuring device based on optical interference according to claim 6, characterized in that: The pitch angle measurement light interference module (34) includes a pitch angle measurement light source (341), a pitch angle measurement spectroscope (342), a first right-angle reflector (343), a second right-angle reflector (344), a third right-angle reflector (345), a first corner cone prism (346), a second corner cone prism (347), and a pitch angle measurement photoelectric detector (348). The pitch angle measurement light source (341), the pitch angle measurement spectroscope (342), the first right-angle reflector (343), the second right-angle reflector (344), the third right-angle reflector (345) and the pitch angle measurement photoelectric detector (348) are all fixed on the movable seat (21), and the first corner cube prism (346) and the second corner cube prism (347) are respectively fixed on the two sliding racks (317); The pitch angle measurement spectroscope (342) reflects a portion of the output light of the pitch angle measurement light source (341) onto the first right-angle reflector (343), and then the light is incident on the first corner cube prism (346) after being reflected by the first right-angle reflector (343) and the second right-angle reflector (344). After being reflected by the first corner cube prism (346), the light is emitted in parallel and then passes through the second right-angle reflector (344), the first right-angle reflector (343) and the pitch angle measurement spectroscope (342) to be transmitted to the pitch angle measurement photoelectric detector (348). The pitch angle measurement spectroscope (342) projects another portion of the light emitted by the displacement measurement light source (231) onto the third right-angle reflector (345), which is then reflected by the third right-angle reflector (345) and incident on the second corner cone prism (347). The light is then reflected by the second corner cone prism (347) and emitted in parallel, and is reflected by the third right-angle reflector (345) and the pitch angle measurement spectroscope (342) in sequence and is then reflected onto the pitch angle measurement photoelectric detector (348).

8. The spindle rotation deviation measuring device based on optical interference according to claim 1, characterized in that: A detection hole (70) for the spindle (200) to move through is provided on a spindle rotation deviation measurement device based on optical interference, and the detection hole (70) passes through the fixed seat (12), the rotating seat (14), the movable seat (21) and the pitch seat (31); The attitude detection light interference module (40) includes a position detection light source (41), a first beam splitter (42), a second beam splitter (43), a third beam splitter (44), a first reflector (45), a second reflector (46), a first photodetector (47), and a second photodetector (48), all of which are fixed on the pitch seat (31); The first beam splitter (42) splits the outgoing light of the position detection light source (41) into a first light beam and a second light beam, wherein: The first beam splitter (42) reflects the first light beam onto the second beam splitter (43), the second beam splitter (43) splits the first light beam into a first light beam A and a first light beam B, the second beam splitter (43) projects the first light beam A onto the first reflector (45), and the first reflector (45) then reflects the first light beam A onto the second beam splitter (43), the second beam splitter (43) reflects part of the second light beam A onto the first photodetector (47); the second beam splitter (43) reflects the first light beam B onto the main shaft (200) in the detection hole (70), the main shaft (200) reflects the first light beam B onto the second beam splitter (43), and the second beam splitter (43) projects part of the first light beam B onto the first photodetector (47); The first beam splitter (42) projects the second light beam onto the third beam splitter (44), the third beam splitter (44) splits the second light beam into a second light beam A and a second light beam B, the third beam splitter (44) projects part of the second light beam A onto the second reflector (46), the part of the second light beam A is reflected by the second reflector (46) onto the third beam splitter (44), the third beam splitter (44) reflects part of the second light beam A onto the second photodetector (48); the third beam splitter (44) reflects the second light beam B onto the main shaft (200) in the detection hole (70), the main shaft (200) reflects the second light beam B onto the third beam splitter (44), and part of the second light beam B passes through the third beam splitter (44) to be projected onto the second photodetector (48).

9. The spindle rotation deviation measuring device based on optical interference according to claim 8, characterized in that: A first through hole (120) coaxial with the first axis (50) is formed on the fixed seat (12), a second through hole (142) coaxial with the first axis (50) is formed on the rotating seat (14), a third through hole (213) is formed on the movable seat (21), and a fourth through hole (311) is formed on the pitch seat (31). The first through hole (120), the second through hole (142), the third through hole (213) and the fourth through hole (311) are connected in sequence to form the detection hole (70), and the first light beam B and the second light beam B are both converged on the central axis of the fourth through hole (311).

10. The spindle rotation deviation measuring device based on optical interference according to claim 8, characterized in that: The attitude detection optical interference module (40) further includes two optical compensation mirrors (492) fixed on the pitch seat (31), wherein one optical compensation mirror (492) is located between the first reflector (45) and the second beam splitter (43), and the other optical compensation mirror (492) is located between the second reflector (46) and the third beam splitter (44).

Images