Spindle axial runout measuring device

Abstract

The application provides a spindle axial displacement measuring device, which comprises a measuring assembly, a calibration assembly and a following assembly. The measuring assembly comprises an optical interference measuring module and a measuring driving part. The optical interference measuring module comprises a mounting seat, a light source, a beam splitter, a fixed mirror, a photodetector and a light shield plate, which are all fixed on the mounting seat. The beam splitter is located on the light path of the light source. The fixed mirror and the photodetector are respectively located on the opposite sides of the beam splitter. The light shield plate is movably connected with the mounting seat. The measuring driving part is connected with the mounting seat. The calibration assembly comprises a calibration driving part and a calibration mirror. The calibration driving part is used for being connected with the spindle. The calibration mirror is arranged on the calibration driving part. The calibration mirror is provided with a mark. The following assembly comprises a fixing part and a corner cube reflector. The corner cube reflector is arranged on the fixing part. The fixing part is detachably arranged on the spindle. The device can improve the precision of the spindle axial displacement measurement.

Description

Technical Field

[0001] This invention relates to high-precision measuring equipment, specifically to a spindle axial movement measuring device. Background Technology

[0002] The spindle is the actuating component of a machine tool. Its function is to support and drive the workpiece or cutting tool to complete surface work, while also transmitting power and torque, and bearing loads such as cutting forces and driving forces. During actual use, due to factors such as poor spindle preload, manufacturing precision of bearings, and assembly / adjustment precision, axial movement of the spindle can occur during machining, leading to a decrease in machining accuracy. Therefore, after machine tool repair, or when the machine tool is used to machine a new workpiece, it is necessary to check the axial movement of the machine tool during operation before formal machining to implement appropriate machining control strategies based on the measured data.

[0003] Chinese invention patent application CN106691A 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 housing for mounting the required instruments, a laser emitter, four optical convex lenses, a semi-transparent mirror, a reference sphere, and a CCD camera installed in the housing. Part of the laser beam will be emitted from the circular hole on the square box and hit the target sphere. The target sphere is mounted on the precision spindle through an extension rod. The analysis principle analyzes the laser interference pattern acquired by the CCD camera to obtain the rotational speed and three-dimensional displacement error of the precision spindle. This invention is convenient for engineering testing, does not require error separation, and can simultaneously detect the rotational speed, axial and radial displacement errors of the precision spindle, and the measurement accuracy reaches the nanometer level. However, in actual use, it still has the following defects: (1) Since it needs to calculate the optical path difference, which is relatively difficult, it needs to install a target sphere at the end of the spindle, calculate the optical path difference according to the special shape of the target sphere, and then obtain the rotational speed, axial and radial displacement errors of the precision spindle according to 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 results may be significantly different from the actual use and ideal state, resulting in reduced measurement accuracy. (2) The Chinese invention patent application CN106691A uses an interferometric test system that is fixed and obtains the deviation of the spindle by calculating the optical path difference between the incident light and the reflected light of the laser emitter. However, the calculation conditions for its optical path difference are harsh. The calculation of the optical path difference is relatively large because the displacement of the main axis 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. (3) This patent can calculate the coordinates of the beam convergence point in the target ball coordinate system, i.e. the position of the target ball center, by the relationship between the three property parameters of the interference image (the ratio of the major axis to the minor axis of the bright fringes of the interference image, the minor axis direction angle, and the spacing between the two bright fringes) and the coefficients of the equation. The control of the precision main axis rotation, the recording of the target ball center movement trajectory, and the projection of the trajectory on the z-axis are all taken. The length of the trajectory is the axial displacement of the precision main axis. The position of the target ball center needs to be converted between the target ball coordinate system and the measurement coordinate system, and the calculation process is complicated. The axial displacement of the main axis is obtained by first calculating the position of the target ball center, then recording the target ball center movement trajectory, and measuring the projection length of the trajectory on the z-axis. It involves several measurement steps, and each measurement step will produce an error, resulting in a decrease in measurement accuracy. Summary of the Invention

[0004] The present invention aims to solve at least one of the technical problems mentioned in the background art above, and to provide a spindle axial movement measuring device that can improve the accuracy of spindle axial movement measurement.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A spindle axial movement measuring device includes:

[0007] The measurement assembly includes an optical interferometry module and a measurement driver. The optical interferometry module includes a mounting base, a light source, a beam splitter, a fixed reflector, a photodetector, and a light shield. The light source, the beam splitter, the fixed reflector, and the photodetector are all fixed on the mounting base. The beam splitter is located in the output light path of the light source. The fixed reflector and the photodetector are located on opposite sides of the beam splitter. The light shield is movably connected to the mounting base and can move between a first position that blocks the light beam from the beam splitter to the fixed reflector and a second position that allows the light beam to pass from the beam splitter to the fixed reflector. The measurement driver is connected to the mounting base to drive the mounting base to move, thereby adjusting the output direction of the light beam from the light source.

[0008] A calibration assembly includes a calibration drive and a calibration mirror. The calibration drive is connected to a spindle, and the calibration mirror is mounted on the side of the calibration drive facing the measurement assembly. The side of the calibration mirror facing the calibration assembly has markings. The calibration mirror is capable of moving and rotating under the drive of the calibration drive.

[0009] The follower assembly includes a fixing member and a pyramidal reflector. The fixing member is used for detachable connection with the main shaft, and the pyramidal reflector is mounted on the end of the fixing member facing the measuring assembly.

[0010] Furthermore, both the measurement drive and the calibration drive include a sliding drive, a fixed base, a rotating ball, and a rotary drive. The sliding drive of the calibration drive is connected to one end of the spindle. The fixed base is connected to the corresponding sliding drive to slide under the drive of the sliding drive. The rotating ball is rotatably mounted on the corresponding fixed base. The rotary drive is mounted on the corresponding fixed base and / or the sliding drive and connected to the corresponding rotating ball to drive the corresponding rotating ball to rotate. The rotating ball of the measurement drive is connected to the mounting base. The calibration reflector is mounted on the rotating ball of the calibration drive.

[0011] Furthermore, the rotary drive includes a first slide, a second slide, a swing ball, and a swing shaft. The first slide is slidably connected to the rotary drive, and the second slide is slidably connected to the first slide. The sliding direction of the second slide is perpendicular to the sliding direction of the first slide. The second slide is provided with a swing groove, and the swing ball is movably installed in the swing groove. One end of the swing shaft is fixed to the swing ball, and the other end of the swing shaft is fixed to the rotating ball.

[0012] Furthermore, the sliding drive component adopts a cross slide.

[0013] Furthermore, the rotating ball of the calibration drive is recessed with a fixing groove, the fixing groove is located on the side of the rotating ball facing the measuring component, the calibration reflector is fixed in the fixing groove, the mark is set at the center of the calibration reflector, and the mark, the center of the rotating ball and the swing axis are located on the same straight line.

[0014] Furthermore, a rotating groove is provided on the side of the fixed base facing the measuring component. The shape of the rotating groove matches the shape of the rotating ball, and the rotating ball is rotatably disposed in the rotating groove.

[0015] Furthermore, the corner cone reflector is a cylindrical mirror, one end of which is fixedly connected to the fixing member, and the end face of the cylindrical mirror facing away from the fixing member is recessed with a reflective groove, which is formed by three mutually perpendicular reflective surfaces.

[0016] Furthermore, the light-shielding plate is slidably connected to the mounting base.

[0017] Furthermore, the calibration component is detachably connected to the spindle via a connector.

[0018] Furthermore, both the connector and the fixing member include a fixing sleeve, an adjusting screw, an adjusting nut, and several claws. The adjusting screw is rotatably connected to the fixing sleeve, and the adjusting nut is housed within the fixing sleeve and threadedly connected to the adjusting screw. The adjusting nut has several inclined driving surfaces spaced circumferentially. Several claws are spaced circumferentially along the adjusting nut, with one end slidingly contacting several driving surfaces. The claws are slidably connected to the fixing sleeve, and the sliding direction of the claws is parallel to the radial direction of the adjusting screw. The corner cone reflector is fixed to one end of the fixing sleeve of the fixing member, and the sliding drive member is fixed to one end of the fixing sleeve of the connector.

[0019] By adopting the above technical solution, the present invention has the following beneficial effects:

[0020] The aforementioned spindle axial runout measuring device includes a measuring component, a calibration component, and a follower component. In use, the calibration component and the follower component are mounted on the spindle. Through the cooperation of the measuring component and the calibration component, the emitted light from the light source in the measuring component can be adjusted to coincide with the rotation center axis of the spindle during operation. After calibrating the emitted light, the calibration component is removed from the spindle, allowing the calibrated emitted light to be projected onto the pyramidal reflector of the follower component, which rotates with the spindle. The pyramidal reflector reflects the emitted light along the emitted light path to a beam splitter. Based on the Michelson interferometry principle, the axial runout displacement during spindle rotation can be calculated using a photodetector. After calibrating the emitted light path, the aforementioned spindle axial runout measuring device can directly calculate the axial runout displacement during spindle rotation through the cooperation of the measuring component and the follower component. Compared to existing technologies that obtain the axial runout displacement error by projecting the trajectory of the target ball's center, this method is simpler and yields more accurate results. Attached Figure Description

[0021] Figure 1 This is a perspective view of a spindle axial movement measuring device according to a preferred embodiment of the present invention;

[0022] Figure 2 for Figure 1 A perspective view of the spindle axial movement measuring device shown from another angle;

[0023] Figure 3 This is a schematic diagram of the structure of the measuring component in the spindle axial movement measuring device of the preferred embodiment of the present invention after removing part of the mounting base. The dashed line in the figure represents the light beam.

[0024] Figure 4 This is a perspective view of the measuring drive and calibration drive components in the spindle axial movement measuring device according to a preferred embodiment of the present invention.

[0025] Figure 5 for Figure 4 The three-dimensional view of the measurement drive and calibration drive after removing part of the mounting bracket is shown.

[0026] Figure 6 for Figure 4 The diagram shows a top view of the measurement or calibration drive.

[0027] Figure 7 for Figure 6 A schematic cross-sectional view of the measurement or calibration drive along line AA.

[0028] Figure 8 This is a schematic diagram of the structure of the spindle axial movement measuring device of the present invention, in which the calibration component and the follower component are installed on the spindle.

[0029] Figure 9 for Figure 8 The right view;

[0030] Figure 10 for Figure 8 A structural diagram from another perspective after removing the main axis;

[0031] Figure 11 This is a perspective view of the fixing component and connecting component in the spindle axial movement measuring device according to a preferred embodiment of the present invention;

[0032] Figure 12 for Figure 11 Left view of the fastener or connector shown;

[0033] Figure 13 for Figure 12 Right view of the fastener or connector shown;

[0034] Figure 14 This is a perspective view of the fastener and connector after removing part of the fixing sleeve, which is a preferred embodiment of the present invention;

[0035] Figure 15 for Figure 14 A perspective view of the fasteners and connectors shown after removing part of the fixing sleeves;

[0036] Figure 16 for Figure 15 A perspective view of the fasteners and connectors shown from another angle;

[0037] Figure 17 A perspective view of the follower component in the spindle axial movement measuring device according to a preferred embodiment of the present invention;

[0038] Figure 18 for Figure 17 The front view of the follower component is shown;

[0039] Figure 19 In step S7 of a preferred embodiment of the present invention, the projection image marked on the light energy distribution map is shown when the light shield is in the first position. The dots in the figure are the projection images marked on the light energy distribution map.

[0040] Figure 20 This is a schematic diagram of the light energy distribution when the light-shielding plate is in the second position in a preferred embodiment of the present invention;

[0041] Figure 21 This is a schematic diagram of the axial displacement of the spindle during one rotation cycle, showing the spindle moving axially three times.

[0042] Explanation of main component symbols

[0043] 10. Measurement component; 12. Optical interferometry module; 121. Mounting base; 1210. Mounting cavity; 1211. Light-transmitting hole; 1213. Window mirror; 1214. Sliding hole; 123. Light source; 125. Beam splitter; 126. Fixed reflector; 127. Photodetector; 128. Light shield; 1281. Limiting protrusion; 14. Measurement drive component; 141. Sliding drive component; 1411. Base; 1412. First slider; 1413. First slider drive component; 1414. Second slider; 1415. Second slider drive component; 143. Fixed base; 1431, rotating groove; 144, rotating ball; 1441, fixed groove; 145, rotation drive; 1451, first slide; 1452, second slide; 1453, swing groove; 1454, swing ball; 1456, swing shaft; 1457, first slide drive; 1458, second slide drive; 20, calibration assembly; 21, calibration drive; 211, sliding drive; 2111, base; 2113, first slider; 2114, first slider drive; 2115, second slider; 2116, second slider drive Components; 213, Fixed base; 2131, Rotating groove; 214, Rotating ball; 2141, Fixed groove; 215, Rotation drive component; 2151, First slide table; 2152, Second slide table; 2153, Swing groove; 2154, Swing ball; 2156, Swing shaft; 2157, First slide table drive component; 2158, Second slide table drive component; 23, Calibration reflector; 231, Mark; 30, Follower assembly; 31, Fixed component; 311, Fixed sleeve; 3110, Guide hole; 312, Adjusting screw; 3123, Polygonal recess; 313, From 314. Driving gear; 3140. Adjusting nut; 315. Drive surface; 3151. Claw; 316. Inclined surface; 3161. Drive gear; 3161. Gear section; 3163. Shaft; 34. Conical reflector; 341. Reflecting surface; 40. Connector; 41. Fixing sleeve; 410. Guide hole; 42. Adjusting screw; 423. Polygonal groove; 43. Driven gear; 44. Adjusting nut; 440. Drive surface; 45. Claw; 451. Inclined surface; 46. Drive gear; 461. Gear section; 463. Shaft; 90. Main shaft; 91. Hollow cavity. Detailed Implementation

[0044] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0045] It should be noted that when a component is described as "fixed to" another component, it can be directly on the other component or may have a component in between. When a component is considered "connected to" another component, it can be directly connected to the other component or may have a component in between. When a component is considered "set on" another component, it can be directly set on the other component or may have a component in between. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0046] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0047] Please also see Figure 1-2 A preferred embodiment of the present invention provides a spindle axial displacement measuring device for measuring the axial displacement of a machine tool spindle 90 during operation. The machine tool spindle 90 is typically a hollow shaft with a hollow cavity 91 extending through it. The spindle axial displacement measuring device includes a measuring component 10, a calibration component 20, and a follower component 30. The measuring component 10 is mounted on an external support (not shown), and the calibration component 20 and the follower component 30 are both mounted on the spindle 90.

[0048] The measurement assembly 10 includes an optical interferometry module 12 and a measurement drive unit 14 connected to the optical interferometry module 12. Please refer to [other documentation / reference needed]. Figure 3The optical interferometry module 12 includes a mounting base 121, a light source 123, a beam splitter 125, a fixed reflector 126, a photodetector 127, and a light shield 128. In this embodiment, the mounting base 121 is shaped like a closed box with a mounting cavity 1210 inside. The light source 123, beam splitter 125, fixed reflector 126, and photodetector 127 are all fixed within the mounting cavity 1210 of the mounting base 121 to better protect them. In this embodiment, a light-transmitting hole 1211 is provided through one side of the mounting base 121 to allow the light beam emitted by the light source 123 to exit the mounting base 121 through the light-transmitting hole 1211, or to allow external light beams to enter the mounting base 121 through the light-transmitting hole 1211. A window mirror 1213 is fixed inside the light-transmitting hole 1211 to seal the light-transmitting hole 1211 and achieve a better dustproof effect. A beam splitter 125 is located on the outgoing light path of the light source 123, and a fixed reflector 126 and a photodetector 127 are located on opposite sides of the beam splitter 125. The photodetector 127 is used to detect light energy. In this embodiment, the photodetector 127 is a CCD image sensor, which can convert the detected light radiation into electrical energy. In use, the output signal of the CCD image sensor is connected to an oscilloscope, image display, or other signal storage device, so that the signal detected by the CCD image sensor can be reproduced to obtain a light energy distribution map. The structure of the CCD image sensor is prior art and will not be described in detail here for brevity.

[0049] The light shield 128 is movably connected to the mounting base 121, and the light shield 128 can move between a first position that blocks the light beam from the beam splitter 125 to the fixed reflector 126 and a second position that allows the light beam to travel from the beam splitter 125 to the fixed reflector 126. In this embodiment, the light-shielding plate 128 is slidably connected to the mounting base 121. Specifically, the mounting base 121 has a sliding hole 1214, which is located on the same side of the mounting base 121 as the light-transmitting hole 1211. The light-shielding plate 128 slides through the sliding hole 1214. When the light-shielding plate 128 is in the first position, it blocks the beam between the fixed reflector 126 and the beam splitter 125, preventing the beam from being projected from the beam splitter 125 onto the fixed reflector 126. When the light-shielding plate 128 is in the second position, it moves away from the position between the fixed reflector 126 and the beam splitter 125, thereby allowing the beam to be projected from the beam splitter 125 onto the fixed reflector 126. In this embodiment, a limiting protrusion 1281 is provided at each of the opposite ends of the light-shielding plate 128. The limiting protrusions 1281 at the opposite ends of the light-shielding plate 128 are located on opposite sides of the sliding hole 1214. The outer diameter of the limiting protrusion 1281 is larger than the diameter of the sliding hole 1214 to prevent the light-shielding plate 128 from detaching from the mounting base 121 when it slides. The light-shielding plate 128 is opaque and has virtually no reflection, thus blocking the light path. The structure of the light-shielding plate 128 is prior art and will not be described in detail here for brevity.

[0050] The measuring drive unit 14 is connected to the mounting base 121 to drive the mounting base 121 to move, thereby adjusting the emission direction of the light beam from the light source 123. Please refer to [further details omitted]. Figures 4 to 7 In this embodiment, the measuring drive 14 includes a sliding drive 141, a fixed base 143, a rotating ball 144, and a rotary drive 145. The fixed base 143 is connected to the sliding drive 141 and slides under the drive of the sliding drive 141. The rotating ball 144 is rotatably disposed on the corresponding fixed base 143 and is connected to the mounting base 121. The rotary drive 145 is mounted on the corresponding fixed base 143 and the sliding drive 141 and is connected to the rotating ball 144 to drive the rotating ball 144 to rotate.

[0051] In this embodiment, the sliding drive 141 adopts a conventional cross slide, which includes a base 1411, a first slider 1412, a first slider drive 1413, a second slider 1414, and a second slider drive 1415. The first slider 1412 is slidably mounted on the base 1411. The first slider drive 1413 is mounted on the base 1411 and connected to the first slider 1412 to drive the first slider 1412 to move along the first direction X. In this embodiment, the first slider drive 1413 is a lead screw drive device, which includes a lead screw (not shown) and a lead screw motor (not shown). The lead screw motor is mounted on the base 1411 and connected to the lead screw. The lead screw is threadedly connected to the first slider 1412, and can rotate under the drive of the lead screw motor, thereby driving the first slider 1412 to reciprocate along the first direction X. The second slider 1414 is slidably mounted on the first slider 1412. The second slider drive 1415 is mounted on the first slider 1412 and connected to the second slider 1414 to drive the second slider 1414 to move along the second direction Y, which is perpendicular to the first direction X. In this embodiment, the second slider drive 1415 is a lead screw drive device, which includes a lead screw (not shown) and a lead screw motor (not shown). The lead screw motor is mounted on the first slider 1412 and connected to the lead screw. The lead screw is threadedly connected to the second slider 1414 and can rotate under the drive of the lead screw motor, thereby driving the second slider 1414 to reciprocate along the second direction Y. It can be understood that the structure of the first slider drive 1413 and the second slider drive 1415 is not limited to the lead screw drive device of this embodiment. Other drive devices in the prior art that can drive the first slider 1412 or the second slider 1414 to move linearly can also be used, or the first slider 1412 or the second slider 1414 can be driven to move linearly by manually rotating the lead screw.

[0052] In this embodiment, the fixing base 143 is fixed to the second slider 1414 of the cross slide table; the fixing base 143 has a rotating groove 1431, the shape of which matches the shape of the rotating ball 144. In this embodiment, the rotating groove 1431 is located on the side of the fixing base 143 facing away from the sliding drive member 141. The rotating ball 144 is rotatably disposed in the rotating groove 1431. In this embodiment, a fixing groove 1441 is recessed on the side of the rotating ball 144 facing away from the sliding drive member 141, and one end of the mounting base 121 facing away from the light-transmitting hole 1211 is inserted and fixed in the fixing groove 1441.

[0053] In this embodiment, the rotary drive 145 includes a first slide 1451, a second slide 1452, a swing ball 1454, and a swing shaft 1456. The first slide 1451 is slidably connected to the second slider 1414 of the sliding drive 211, and the second slide 1452 is slidably connected to the first slide 1451. The sliding direction of the second slide 1452 is perpendicular to the sliding direction of the first slide 1451. In this embodiment, the sliding direction of the first slide 1451 is parallel to the first direction X, and the sliding direction of the second slide 1452 is parallel to the second direction Y. The second slide 1452 is provided with a swing groove 1453. In this embodiment, the swing groove 1453 is recessed on the side of the second slide 1452 facing away from the first slide 1451. The swing ball 1454 is movably installed in the swing groove 1453. One end of the swing shaft 1456 is fixed to the swing ball 1454, and the other end of the swing shaft 1456 is fixed to one side of the rotating ball 1454. When the first slide 1451 and / or the second slide 1452 slide, the rotating ball 144 can rotate in any direction within the rotating groove 1431 through the cooperation of the swing ball 1454 and the swing shaft 1456. In this embodiment, the rotary drive 145 also includes a first slide drive 1457 and a second slide drive 1458. The first slide drive 1457 is mounted on the fixed base 143 and connected to the first slide 1451 to drive the first slide 1451 to slide along the first direction X. In this embodiment, the first slide drive 1457 is a lead screw drive device, which includes a lead screw and a lead screw motor. The lead screw motor is mounted on the fixed base 143 and connected to the lead screw. The lead screw is threadedly connected to the first slide 1451 and can rotate under the drive of the lead screw motor, thereby driving the first slide 1451 to reciprocate along the first direction X. The second slide drive 1458 is mounted on the first slide 1451 and connected to the second slide 1452 to drive the second slide 1452 to slide along the second direction Y. In this embodiment, the second slide drive 1458 is a lead screw drive device, which includes a lead screw and a lead screw motor. The lead screw motor is mounted on the first slide 1451 and connected to the lead screw. The lead screw is threadedly connected to the second slide 1452 and can rotate under the drive of the lead screw motor, thereby driving the second slide 1452 to reciprocate along the second direction Y. It can be understood that the structure of the first slide drive 1457 and the second slide drive 1458 is not limited to the lead screw drive device of this embodiment. They can also adopt other drive devices in the prior art that can drive the first slide 1451 or the second slide 1452 to linear motion, or the first slide 1451 or the second slide 1452 can be driven to linear motion by manually rotating the lead screw.

[0054] Please see also Figures 8 to 10The calibration component 20 is arranged opposite to the measurement component 10 and includes a calibration drive 21 and a calibration mirror 23. The calibration drive 21 is used to connect to the spindle 90. The calibration mirror 23 is installed on the side of the calibration drive 21 facing the measurement component 10. The side of the calibration mirror 23 facing the calibration component 20 is marked with a mark 231. The calibration mirror 23 can move and rotate under the drive of the calibration drive 21.

[0055] Please see again Figures 4 to 7 In this embodiment, the structure of the calibration drive 21 is the same as that of the measurement drive 14, both including a sliding drive 211, a fixed base 213, a rotating ball 214 and a rotary drive 215. The fixed base 213 is connected to the sliding drive 211 so as to slide under the drive of the sliding drive 211; the rotating ball 214 is rotatably disposed on the fixed base 213; the rotary drive 215 is mounted on the fixed base 213 and the sliding drive 211 and is connected to the rotating ball 214 so as to drive the rotating ball 214 to rotate.

[0056] In this embodiment, the sliding drive 211 is a cross slide, which includes a base 2111, a first slider 2113, a first slider drive 2114, a second slider 2115, and a second slider drive 2116. The first slider 2113 is slidably mounted on the base 2111. The first slider drive 2114 is mounted on the base 2111 and connected to the first slider 2113 to drive the first slider 2113 to move along the first direction X. In this embodiment, the first slider drive 2114 is a lead screw drive device, which includes a lead screw and a lead screw motor. The lead screw motor is mounted on the base 2111 and connected to the lead screw. The lead screw is threadedly connected to the first slider 2113 and can rotate under the drive of the lead screw motor, thereby driving the first slider 2113 to reciprocate along the first direction X. The second slider 2115 is slidably mounted on the first slider 2113. The second slider drive 2116 is mounted on the first slider 2113 and connected to the second slider 2115 to drive the second slider 2115 to move along the second direction Y, which is perpendicular to the first direction X. In this embodiment, the second slider drive 2116 is a lead screw drive device, which includes a lead screw and a lead screw motor. The lead screw motor is mounted on the first slider 2113 and connected to the lead screw. The lead screw is threadedly connected to the second slider 2115 and can rotate under the drive of the lead screw motor, thereby driving the second slider 2115 to reciprocate along the second direction Y. It can be understood that the structure of the first slider drive 2114 and the second slider drive 2116 is not limited to the lead screw drive device of this embodiment. They can also adopt other drive devices in the prior art that can drive the first slider 2113 or the second slider 2115 to move linearly, or the first slider 2113 or the second slider 2115 can be driven to move linearly by manually rotating the lead screw.

[0057] In this embodiment, the fixed base 213 is fixed to the second slider 2115 of the cross slide table; the fixed base 213 has a rotating groove 2131, the shape of which matches the shape of the rotating ball 214. In this embodiment, the rotating groove 2131 is located on the side of the fixed base 213 facing away from the sliding drive member 211. The rotating ball 214 is rotatably disposed in the rotating groove 2131.

[0058] In this embodiment, the rotary drive 215 includes a first slide 2151, a second slide 2152, a swing ball 2154, and a swing shaft 2156. The first slide 2151 is slidably connected to the second slider 2115 of the sliding drive 211, and the second slide 2152 is slidably connected to the first slide 2151. The sliding direction of the second slide 2152 is perpendicular to the sliding direction of the first slide 2151. In this embodiment, the sliding direction of the first slide 2151 is parallel to the first direction X, and the sliding direction of the second slide 2152 is parallel to the second direction Y. The second slide 2152 is provided with a swing groove 2153, which is recessed in the side of the second slide 2152 facing away from the first slide 2151. The swing ball 2154 is rotatably mounted in the swing groove 2153. One end of the swing shaft 2156 is fixed to the swing ball 2154, and the other end of the swing shaft 2156 is fixed to one side of the rotating ball 2154. When the first slide 2151 and / or the second slide 2152 slide, the rotating ball 214 can rotate in any direction within the rotating groove 2131 through the cooperation of the swing ball 2154 and the swing shaft 2156. In this embodiment, the rotary drive 215 also includes a first slide drive 2157 and a second slide drive 2158. The first slide drive 2157 is mounted on the fixed base 213 and connected to the first slide 2151 to drive the first slide 2151 to slide along the first direction X. In this embodiment, the first slide drive 2157 is a screw drive device, which includes a screw and a screw motor. The screw motor is mounted on the fixed base 213 and connected to the screw. The screw is threadedly connected to the first slide 2151 and can rotate under the drive of the screw motor, thereby driving the first slide 2151 to reciprocate along the first direction X. The second slide drive 2158 is mounted on the first slide 2151 and connected to the second slide 2152 to drive the second slide 2152 to slide along the second direction Y. In this embodiment, the second slide drive 2158 is a lead screw drive device, which includes a lead screw and a lead screw motor. The lead screw motor is mounted on the first slide 2151 and connected to the lead screw. The lead screw is threadedly connected to the second slide 2152 and can rotate under the drive of the lead screw motor, thereby driving the second slide 2152 to reciprocate along the second direction Y. It can be understood that the structure of the first slide drive 2157 and the second slide drive 2158 is not limited to the lead screw drive device of this embodiment. They can also adopt other drive devices in the prior art that can drive the first slide 2151 or the second slide 2152 to linear motion, or the first slide 2151 or the second slide 2152 can be driven to linear motion by manually rotating the lead screw.

[0059] The calibration reflector 23 is mounted on the rotating ball 214 of the calibration drive component 21. In this embodiment, the rotating ball 214 has a recessed fixing groove 2141 on the side facing the measuring component 10. The calibration reflector 23 is fixed in the fixing groove 2141. A mark 231 is located at the center of the calibration reflector 23. The mark 231, the center of the rotating ball 214, and the swing axis 2156 are all on the same straight line. The mark 231 can be formed by coating the calibration reflector 23 with black paint or by engraving on the calibration reflector 23. Its shape can be circular, cross-shaped, etc., as needed.

[0060] The sliding drive 211 of the calibration drive 21 is used to connect to one end of the spindle 90. In this embodiment, the seat 1411 of the sliding drive 211 is detachably connected to the spindle 90 via the connector 40.

[0061] Please see also Figures 11 to 16 The connecting member 40 includes a fixed sleeve 41, an adjusting screw 42, an adjusting nut 44, and several claws 45. One end of the fixed sleeve 41 is fixedly connected to the seat 2111 of the sliding drive member 211. The adjusting screw 42 is rotatably connected to the fixed sleeve 41. In this embodiment, one end of the adjusting screw 42 is inserted into the fixed sleeve 41, and the other end is located outside the fixed sleeve 41. The circumferential surface of the adjusting screw 42 is provided with two threaded sections with opposite directions of rotation (not shown in the figure), and the two threaded sections are spaced apart along the axial direction of the adjusting screw 42. The adjusting nut 44 is received in the fixed sleeve 41 and threadedly connected to the adjusting screw 42. In this embodiment, there are two adjusting nuts 44, and the two adjusting nuts 44 are respectively threadedly connected to the two threaded sections on the adjusting screw 42. Each adjusting nut 44 is provided with several inclined driving surfaces 440 spaced apart along the circumferential direction; in this embodiment, the driving surfaces 440 gradually incline from the end of the adjusting screw 42 to the center of the adjusting screw 42 towards the direction closer to the central axis of the adjusting screw 42. Several pawls 45 are spaced apart circumferentially along the adjusting nut 44, with one end slidingly contacting several driving surfaces 440 respectively. The pawls 45 are slidably connected to the fixed sleeve 41, and the sliding direction of the pawls 45 is parallel to the radial direction of the adjusting screw 42. Specifically, in this embodiment, the fixed sleeve 41 has several guide holes 410 for the pawls 45. The guide holes 410 extend radially along the adjusting screw 42 and communicate with the inner cavity of the fixed sleeve 41. The pawls 45 slide through the guide holes 410 respectively. One end of each pawl 45 is located inside the fixed sleeve 41 and slides in contact with the corresponding driving surface 440. In this embodiment, the end of the pawl 45 located inside the fixed sleeve 41 has an inclined surface 451 that slides with the driving surface 440. The other end of each pawl 45 is located outside the fixed sleeve 41 to abut against the inner wall of the hollow cavity 91 of the spindle 90.

[0062] In use, the connector 40 is inserted into the hollow cavity 91 of the spindle 90. The adjusting screw 42 is rotated, which causes the two adjusting nuts 44 to move towards each other or away from each other. When the two adjusting nuts 44 move towards each other, the adjusting nuts 44 push the corresponding claws 45 towards the inner wall of the hollow cavity 91 of the spindle 90 through the driving surfaces 440 on them, until they are pressed against the inner wall of the hollow cavity 91 of the spindle 90, thereby connecting the connector 40 and the calibration drive 21 connected to the connector 40 to the spindle 90. When the two adjusting nuts 44 move away from each other, the claws 45 are no longer pressed against the inner wall of the hollow cavity 91 of the spindle 90, thus allowing the user to remove the connector 40 and the calibration drive connected to the connector 40 from the spindle 90.

[0063] The adjusting screw 42 has a first end (not shown) and a second end (not shown) disposed opposite to each other. In this embodiment, the first end of the adjusting screw 42 is farther away from the seat 2111 of the sliding drive member 211 than the second end. To facilitate rotation of the adjusting screw 42, the first end of the adjusting screw 42 extends out of the fixing sleeve 41. In this embodiment, a polygonal recess 423 is also provided on the first end of the adjusting screw 42 to facilitate rotation of the adjusting screw 42 using tools such as a screwdriver. Furthermore, in this embodiment, a driven gear 43 is fixedly sleeved on the second end of the adjusting screw 42. In this embodiment, the driven gear 43 is rotatably housed within the fixed sleeve 41. A driving gear 46 is rotatably connected to the fixed sleeve 41, and the driving gear 46 meshes with the driven gear 43. In this embodiment, the driving gear 46 includes a gear portion 461 and a shaft 463 fixedly connected to the gear portion 461. The gear portion 461 is located within the fixed sleeve 41 and meshes with the driven gear 43. The shaft 463 rotatably passes through the fixed sleeve 41. In use, the driving gear 46 can be rotated by rotating the shaft 463, thereby driving the driven gear 43 and the adjusting screw 42 to rotate. In this embodiment, both the gear portion 461 and the driven gear 43 are bevel gears.

[0064] Please see also Figure 17 and Figure 18 The follower assembly 30 includes a fixing member 31 and a corner bevel mirror 34. The corner bevel mirror 34 is mounted on the end of the fixing member 31 facing the measuring assembly 10, and the corner bevel mirror 34 is detachably mounted on the spindle 90 via the fixing member 31.

[0065] In this embodiment, the fixing member 31 and the connecting member 40 have the same structure, both including a fixing sleeve 311, an adjusting screw 312, an adjusting nut 314, and several claws 315. The adjusting screw 312 is rotatably connected to the fixing sleeve 311. In this embodiment, one end of the adjusting screw 312 is inserted into the fixing sleeve 311, and the other end is located outside the fixing sleeve 311. The circumferential surface of the adjusting screw 312 is provided with two threaded sections with opposite directions of rotation, and the two threaded sections are spaced apart along the axial direction of the adjusting screw 312. The adjusting nut 314 is received in the fixing sleeve 311 and threadedly connected to the adjusting screw 312. In this embodiment, there are two adjusting nuts 314, and the two adjusting nuts 314 are respectively threadedly connected to the two threaded sections on the adjusting screw 312. Each adjusting nut 314 is provided with a plurality of inclined driving surfaces 3140 at circumferential intervals; in this embodiment, the driving surfaces 3140 gradually incline from the end of the adjusting screw 312 to the center of the adjusting screw 312 toward the direction closer to the central axis of the adjusting screw 312. A plurality of pawls 315 are spaced apart circumferentially along the adjusting nut 314, with one end slidingly contacting a plurality of driving surfaces 3140. The pawls 315 are movably slidably connected to the fixed sleeve 311, and the sliding direction of the pawls 315 is parallel to the radial direction of the adjusting screw 312. Specifically, in this embodiment, the fixed sleeve 311 has a plurality of guide holes 3110 for the plurality of pawls 315. The guide holes 3110 extend radially along the adjusting screw 312 and communicate with the inner cavity of the fixed sleeve 311. The plurality of pawls 315 slide through the plurality of guide holes 3110 respectively. One end of each pawl 315 is located inside the fixed sleeve 311 and slides in contact with the corresponding driving surface 3140. In this embodiment, the end of the pawl 315 located inside the fixed sleeve 311 has an inclined surface 3151 that slides in cooperation with the driving surface 3140. The other end of each pawl 315 is located outside the fixed sleeve 311 to abut against the inner wall of the hollow cavity 91 of the main shaft 90.

[0066] In use, the fixing member 31 is inserted into the hollow cavity 91 of the spindle 90. The adjusting screw 312 is rotated, which drives the two adjusting nuts 314 to move towards each other or away from each other. When the two adjusting nuts 314 move towards each other, the adjusting nuts 314 push the corresponding claws 315 towards the inner wall of the hollow cavity 91 of the spindle 90 through the driving surfaces 3140 on them, until they are pressed against the inner wall of the hollow cavity 91 of the spindle 90, thereby connecting the fixing member 31 and the calibration drive 21 connected to the fixing member 31 to the spindle 90. When the two adjusting nuts 314 move away from each other, the claws 315 are no longer pressed against the inner wall of the hollow cavity 91 of the spindle 90, thus allowing the user to remove the fixing member 31 and the calibration drive connected to the fixing member 31 from the spindle 90.

[0067] The adjusting screw 312 has a first end and a second end that are arranged opposite to each other. In this embodiment, to facilitate rotation of the adjusting screw 312, the first end of the adjusting screw 312 extends out of the fixing sleeve 311. In this embodiment, a polygonal recess 3123 is also provided on the first end of the adjusting screw 312 to facilitate rotation of the adjusting screw 312 with a screwdriver or other tools. In addition, in this embodiment, a driven gear 313 is fixedly sleeved on the second end of the adjusting screw 312. In this embodiment, the driven gear 313 is rotatably housed in the fixing sleeve 311. A driving gear 316 is rotatably connected to the fixing sleeve 311. The driving gear 316 meshes with the driven gear 313. In this embodiment, the driving gear 316 includes a gear part 3161 and a shaft 3163 fixedly connected to the gear part 3161. The gear part 3161 is located in the fixing sleeve 311 and meshes with the driven gear 313. The shaft 3163 rotatably passes through the fixing sleeve 311. In use, the drive gear 316 can be rotated by rotating the shaft 3163, which in turn drives the driven gear 313 and the adjusting screw 312 to rotate. In this embodiment, both the gear part 3161 and the driven gear 313 are bevel gears.

[0068] In this embodiment, the corner bevel reflector 34 is fixed to one end of the fixing sleeve 311 in the fixing member 31. Specifically, the corner bevel reflector 34 is fixed to the end face of the fixing sleeve 311 away from the first end of the adjusting screw 312. The corner bevel reflector 34 is a cylindrical mirror. One end of the cylindrical mirror is fixedly connected to the fixing member 31. The end face of the cylindrical mirror facing away from the fixing member 31 is recessed with a reflective groove (not shown). The reflective groove is formed by three mutually perpendicular reflective surfaces 341.

[0069] When using this spindle axial displacement measuring device to detect the axial displacement of the spindle 90 during operation, the steps are roughly as follows:

[0070] S1, install the calibration component 20 at the tail end of the spindle 90. Specifically, insert the end of the connector 40 fixed to the calibration component 20 away from the calibration component 20 into the hollow cavity 91 of the spindle 90. Rotate the drive gear 316 of the connector 40 to drive the adjusting screw 312 of the connector 40 to move until the pawl 315 of the connector 40 abuts against the inner wall of the hollow cavity 91 of the spindle 90.

[0071] S2, install the follower assembly 30 on the shaft end of the spindle 90. Specifically, insert one end of the fixing member 31 of the follower assembly 30, which has a calibration reflector 23, into the hollow cavity 91 of the spindle 90, so that the calibration reflector 23 faces the calibration assembly 20. Rotate the end of the adjusting screw 312 located outside the fixing sleeve 311 until the pawl 315 of the connector 40 abuts against the inner wall of the hollow cavity 91 of the spindle 90.

[0072] S3, Install the measurement component 10. Specifically, install the seat 1411 of the sliding drive 141 in the measurement component 10 on the machine tool frame or external support, so that the optical interference measurement module 12 of the measurement component 10 faces the calibration reflector 23 of the calibration component 20.

[0073] S4, slide the light-shielding plate 128 to place the light-shielding plate 128 in the first position between the beam splitter 125 and the fixed reflector 126;

[0074] S5, turn on the light source 123, the light emitted from the light source 123 is split into a first beam and a second beam by the beam splitter 125, the first beam is reflected by the beam splitter 125 onto the light shield 128, and the second beam is emitted towards the measuring component 10 through the beam splitter 125.

[0075] S6, adjust the sliding drive 141 of the measurement drive 14 and / or the sliding drive 211 of the calibration component 20 so that the second beam illuminates the mark 231 of the calibration mirror 23 of the calibration component 20. Specifically, the optical interferometry module 12 and / or the calibration mirror 23 can be slid by adjusting the cross slide, so that the second beam illuminates the mark 231 of the calibration mirror 23 of the calibration component 20.

[0076] S7, after the second beam illuminates the calibration mirror 23, it is reflected by the calibration mirror 23 onto the beam splitter 125. The beam splitter 125 reflects a portion of the second beam onto the photodetector 127. Because the light shield 128 blocks the beam splitter 125 and the fixed mirror 126, the photodetector 127 does not receive the beam reflected back from the fixed mirror 126, and therefore, interference fringes will not appear on the light energy distribution map detected by the photodetector 127. Adjusting the sliding drive 141 of the measurement drive 14 and / or the sliding drive 211 of the calibration drive 21, the projected image of mark 231 on the calibration mirror 23 is displayed on the light energy distribution map, such as... Figure 19 As shown, Figure 19 The X-axis of the light energy distribution map shown is a third direction that is perpendicular to both the first direction X and the second direction Y. The Y-axis of the light energy distribution map is parallel to the first direction X.

[0077] S8, adjust the sliding drive 141 of the measurement drive 14 and / or the sliding drive 211 of the calibration drive 21 so that the projected image of the mark 231 is located at the center of the light energy distribution map; the adjustment method of the measurement drive 14 and the calibration drive 21 is the same as that of step S6, and will not be described again here for the sake of brevity.

[0078] S9. Rotate the main shaft 90 slowly, for example, at a speed of no more than 200 revolutions per minute. Observe the position of the projected image of mark 231 on the light energy distribution map. If the projected image of mark 231 deviates from the center of the light energy distribution map during the rotation of the main shaft 90, it indicates that the second beam is not aligned with the axis of rotation when the main shaft 90 rotates. At this time, the trajectory of the projected image of mark 231 on the light energy distribution map during the rotation of the main shaft 90 is a closed loop.

[0079] S10, adjust the sliding drive 211 of the calibration drive 21 until the circular motion trajectory of the projected image of the mark 231 on the light energy distribution map shrinks to the minimum, indicating that the mark 231 on the calibration mirror 23 is on the same straight line as the rotation axis of the main shaft 90 when it is working, but the calibration mirror 23 is not perpendicular to the rotation axis of the main shaft 90 when it is working after rotation.

[0080] S11, adjust the rotation drive 215 of the calibration drive 21, drive the rotating ball 214 and calibration mirror 23 of the calibration component 20 to rotate through the rotation drive 215, observe the motion trajectory of the projected image of the mark 231 in the light energy distribution map, until the motion trajectory of the mark 231 is a straight line, indicating that the calibration mirror 23 is perpendicular to the rotation axis of the main shaft 90 when it is working after rotation.

[0081] S12, adjust the rotation drive 145 of the measuring drive 14 to adjust the emission direction of the second beam of the light source 123, and observe the trajectory of the projected image of the mark 231 in the light energy distribution map. If the projected image of the mark 231 does not move in the light energy distribution map but is not in the center of the light energy distribution map, it means that the second beam of the light source 123 is parallel to the axis of rotation of the main shaft 90 but is not on the same straight line.

[0082] S13, adjust the sliding drive 141 of the measuring drive 14, observe the trajectory of the projected image of mark 231 in the light energy distribution map. If the projected image of mark 231 is stationary in the light energy distribution map and is located at the center of the light energy distribution map, it indicates that the second beam of the light source 123 coincides with the rotation axis when the main shaft 90 rotates, thus completing the adjustment of the light path of the light source 123.

[0083] S14, after completing the adjustment of the optical path of the light source 123, move the light shield 128 to the second position so that the first beam of the light source 123 can be reflected by the beam splitter 125 to the fixed reflector 126, the fixed reflector 126 reflects the first beam to the beam splitter 125 again, and the beam splitter 125 reflects part of the first beam to the photodetector 127.

[0084] S15, stop the rotation of the main shaft 90, remove the calibration component 20 from the tail end of the main shaft 90, and allow the second beam of the light source 123 to be incident along the rotation axis of the main shaft 90 onto the reflecting surface 341 of the corner bevel mirror 34 of the follower component 30. Since the three reflecting surfaces 341 on the corner bevel mirror 34 are perpendicular to each other, the second beam can be reflected along the rotation axis of the main shaft 90 to the beam splitter 125 through the cooperation of the reflecting surfaces 341 on the corner bevel mirror 34. The beam splitter 125 reflects part of the second beam to the photodetector 127. This part of the second beam interferes with part of the first beam in step S13 at the photodetector 127 to obtain a light energy distribution map.

[0085] S16, the workpiece to be processed is installed at the end of the spindle 90, and the spindle 90 is rotated at a predetermined processing speed. The axial displacement value of the spindle 90 during operation can be obtained by observing the light energy distribution map obtained on the photodetector 127.

[0086] In step S16, the photodetector 127 is connected to a data processing device such as a computer. The number of left and right movements of the interference fringes within the spindle rotation cycle is obtained through the computer or other data processing device. This is prior art and will not be described in detail here for brevity. The displacement d of the corner bevel mirror 34 relative to the fixed mirror 126 is obtained by obtaining the number of left and right movements of the interference fringes within the spindle rotation cycle. Specifically, in this embodiment, the normal of the fixed mirror 126 is not perpendicular to the emitted beam of the light source 123. The relative movement of the corner bevel mirror 34 and the fixed mirror 126 generates interference fringes on the entire surface of the CCD. The direction of the interference fringes movement is related to the direction of the spindle axial movement. The light energy generates straight interference fringes (such as...) on the entire CCD image sensor. Figure 20 (As shown). In most cases, within one rotation cycle of the main shaft (the rotation cycle of the main shaft is the time it takes for the main shaft to rotate once, which can be calculated from the rotational speed of the main shaft), the main shaft usually only moves axially once. At this time, if the displacement d of the pyramidal reflector 34 relative to the fixed reflector 126 is , then d = Nλ / 2, where N is the number of left and right shifts of the interference fringes in the light energy distribution image during the movement of the pyramidal reflector 34 relative to the fixed reflector 126, and λ is the wavelength of the emitted beam from the light source. Since the pyramidal reflector 34 is fixed on the main shaft 90 and moves with the main shaft 90, the displacement d of the pyramidal reflector 34 relative to the fixed reflector 126 is the axial displacement of the main shaft 90. If the main shaft moves axially multiple times within one rotation cycle, the displacement value with the largest axial displacement is taken as the axial displacement of the main shaft. For example, as shown... Figure 21 As shown, Figure 21The horizontal direction is the axis of rotation of the main shaft. The main shaft axially rotates three times during its rotation period. Let's assume that during the first axial rotation, the main shaft moves to the right along the axis of rotation by a displacement of d1. At this time, the interference fringes in the light energy distribution image shift to the right. The value of d1 can be calculated by calculating the amount of rightward shift of the interference fringes. Then, the main shaft moves to the left along the axis of rotation in the opposite direction by a displacement of d2. At this time, the interference fringes in the light energy distribution image shift to the left. The value of d2 can be calculated by calculating the amount of leftward shift of the interference fringes. Afterward, the main shaft undergoes a second axial rotation. Let's assume that during the second axial rotation, the main shaft moves to the right along the axis of rotation by a displacement of d3. At this time, the interference fringes in the light energy distribution image shift to the right. The value of d3 can be calculated by calculating the amount by which the interference fringes shift to the right. Then, the main shaft moves back along the rotation axis by a displacement of d4. At this point, the interference fringes in the light energy distribution image shift to the left. The value of d4 can be calculated by calculating the amount by which the interference fringes shift to the left. Finally, the main shaft performs a third axial movement and resets. Let's assume that during this third axial movement, the main shaft moves back to the right along the rotation axis by a displacement of d5. At this point, the interference fringes in the light energy distribution image shift to the right. The value of d5 can be calculated by calculating the amount by which the interference fringes shift to the right. Finally, the main shaft moves back along the rotation axis to its reset position by a displacement of d6. The value of d6 can be calculated by calculating the amount by which the interference fringes shift to the left. Therefore, from... Figure 21 It can be seen that the second axial displacement of the spindle is the largest. The displacement value of the second axial displacement of the spindle is taken as the axial displacement d of the spindle, and d = (d1-d2)+d3, or d = (d4-d5)+d6.

[0087] The aforementioned spindle axial displacement measuring device includes a measuring component 10, a calibration component 20, and a follower component 30. In use, the calibration component 20 and the follower component 30 are mounted on the spindle 90. Through the cooperation of the measuring component 10 and the calibration component 20, the emitted light of the light source 123 in the measuring component 10 can be adjusted to coincide with the rotation center axis of the spindle 90, thus completing the calibration of the emitted light of the light source 123. The calibration component 20 is then removed from the spindle 90, so that the calibrated emitted light of the light source 123 is projected onto the corner bevel mirror 34 of the follower component 30, which rotates with the spindle 90. The corner bevel mirror 34 reflects the emitted light of the light source 123 along the emitted light path to the beam splitter 125. Based on the Michelson interference principle, the axial displacement of the spindle 90 during rotation can be calculated by the photodetector 127. After the emitted light is calibrated, the above-mentioned spindle axial displacement measuring device can directly calculate the axial displacement of the spindle 90 when it rotates by the cooperation of the measuring component 10 and the follower component 30. Compared with the existing technology, which obtains the axial displacement error of the spindle 90 by making a projection diagram of the trajectory of the target ball center, the calculation is simpler and the measurement result is more accurate.

[0088] The aforementioned spindle axial displacement measuring device reflects the emitted light from the light source 123 along the emitted light path to the beam splitter 125 via a pyramidal reflector 34 at one end of the follower component 30. When the emitted light from the light source 123 is aligned with the rotation center axis of the spindle 90 during rotation, the incident light beam incident on the pyramidal reflector 34 and the reflected light beam reflected by the pyramidal reflector 34 are both parallel to the rotation center axis of the spindle 90 during rotation, through the three mutually perpendicular reflecting surfaces 341 on the pyramidal reflector 34. Furthermore, the concave reflecting groove formed by the three mutually perpendicular reflecting surfaces 341 of the pyramidal reflector 34 can prevent the light beam from generating an optical path difference when the spindle 90 deflects, and prevent radial runout and rotational offset during the rotation of the spindle 90 from affecting the measurement of the axial displacement of the spindle 90. This ensures that the displacement detected by the optical interferometry module 12 is the axial displacement of the spindle 90, thereby improving the measurement accuracy.

[0089] The aforementioned spindle axial movement measuring device allows the follower component 30 to be installed inside the spindle 90 using a fixing component 31. Therefore, after calibrating the output optical path of the light source 123, the actual machined component can be installed on the end face of the spindle 90, and the axial movement of the spindle 90 can be measured at the actual machining speed of the spindle 90. This measurement is more consistent with the actual machining situation of the spindle 90, resulting in higher measurement accuracy. This embodiment does not require the calculation of optical path difference or the use of a target ball, avoiding the problem of complex optical path difference calculation requiring the use of standard balls, target balls, etc., which leads to harsh measurement conditions. It can also prevent errors in the accuracy measurement of the spindle 90 caused by the estimation of optical path difference.

[0090] It is understood that the structure of the calibration drive 21 and the measurement drive 14 is not limited to this embodiment. Any drive device that can adjust the optical path of the light source 123 and the attitude of the calibration mirror 23 is acceptable. Different drive devices can also be used to structure the calibration drive 21 and the measurement drive 14.

[0091] It is understood that the structure of the fixing member 31 and the connecting member 40 is not limited to this embodiment. They can also adopt other connection mechanisms with existing technology, as long as they can detachably connect the corner cone reflector 34 and the calibration component 20 to the main shaft 90. The fixing member 31 and the connecting member 40 can also adopt connection mechanisms with different structures.

[0092] It is understandable that the light shield 128 can also be movably connected to the mounting base 121 by means of detachment, as long as it can block or open the optical path between the fixed reflector 126 and the beam splitter 125.

[0093] The above description is a detailed description of the preferred embodiments of the present invention. However, the embodiments are not intended to limit the scope of the patent application of the present invention. All equivalent changes or modifications made under the technical spirit of the present invention should fall within the patent scope covered by the present invention.

Claims

1. A spindle axial movement measuring device, wherein the spindle is a hollow shaft, characterized in that, include: A measurement assembly includes an optical interferometry module and a measurement drive unit. The measurement assembly is mounted on the machine tool frame or an external support. The optical interferometry module includes a mounting base, a light source, a beam splitter, a fixed reflector, a photodetector, and a light shield. The light source, the beam splitter, the fixed reflector, and the photodetector are all fixed on the mounting base. The beam splitter is located in the output light path of the light source. The fixed reflector and the photodetector are located on opposite sides of the beam splitter. The light shield is movably connected to the mounting base and can move between a first position that blocks the light beam from the beam splitter to the fixed reflector and a second position that allows the light beam to pass from the beam splitter to the fixed reflector. The measurement drive unit is connected to the mounting base to drive the mounting base to move, thereby adjusting the output direction of the light beam from the light source. A calibration assembly includes a calibration drive and a calibration mirror. The calibration assembly is detachably connected to the spindle via a connector inserted into the tail end of the spindle within a hollow cavity. The calibration drive is used to connect to the spindle. The calibration mirror is mounted on the side of the calibration drive facing the measurement assembly, and the side of the calibration mirror facing the measurement assembly has markings. The calibration mirror can move and rotate under the drive of the calibration drive. A light-shielding plate is located in a first position. Through the cooperation of the measurement assembly and the calibration assembly, the emitted light from the light source in the measurement assembly can be adjusted to coincide with the rotation center axis of the spindle during operation. After calibrating the emitted light from the light source, the calibration assembly is removed from the spindle. The follower assembly includes a fixing member and a pyramidal reflector. The fixing member is detachably connected to the main shaft and is inserted into the shaft end inside the hollow cavity of the main shaft. The pyramidal reflector is mounted on the side of the fixing member facing the measuring assembly. The light shield is located in a second position. The calibrated light emitted from the light source is projected onto the pyramidal reflector of the follower assembly that rotates with the main shaft. The pyramidal reflector reflects the light emitted from the light source along the light path to the beam splitter. Based on the Michelson interferometry principle, the axial displacement of the main shaft during rotation is calculated by the light energy distribution map obtained on the photodetector.

2. The spindle axial movement measuring device as claimed in claim 1, characterized in that, Both the measurement drive and the calibration drive include a sliding drive, a fixed base, a rotating ball, and a rotary drive. The sliding drive of the calibration drive is connected to one end of the spindle. The fixed base is connected to the corresponding sliding drive to slide under the drive of the sliding drive. The rotating ball is rotatably mounted on the corresponding fixed base. The rotary drive is mounted on the corresponding fixed base and / or the sliding drive and connected to the corresponding rotating ball to drive the corresponding rotating ball to rotate. The rotating ball of the measurement drive is connected to the mounting base. The calibration reflector is mounted on the rotating ball of the calibration drive.

3. The spindle axial movement measuring device as claimed in claim 2, characterized in that, The rotary drive includes a first slide, a second slide, a swing ball, and a swing shaft. The first slide is slidably connected to the rotary drive, and the second slide is slidably connected to the first slide. The sliding direction of the second slide is perpendicular to the sliding direction of the first slide. The second slide is provided with a swing groove, and the swing ball is movably installed in the swing groove. One end of the swing shaft is fixed to the swing ball, and the other end of the swing shaft is fixed to the rotating ball.

4. The spindle axial movement measuring device as claimed in claim 2, characterized in that, The sliding drive component is a cross slide.

5. The spindle axial movement measuring device as claimed in claim 3, characterized in that, The rotating ball of the calibration drive is recessed with a fixing groove, which is located on the side of the rotating ball facing the measuring component. The calibration reflector is fixed in the fixing groove, and the mark is located at the center of the calibration reflector. The mark, the center of the rotating ball, and the swing axis are located on the same straight line.

6. The spindle axial movement measuring device as claimed in claim 2, characterized in that, The fixed base is provided with a rotating groove, the shape of which matches the shape of the rotating ball, and the rotating ball is rotatably disposed in the rotating groove.

7. The spindle axial movement measuring device as claimed in claim 1, characterized in that, The corner cone reflector is a cylindrical mirror. One end of the cylindrical mirror is fixedly connected to the fixing member. The end face of the cylindrical mirror facing away from the fixing member is recessed with a reflective groove, which is formed by three mutually perpendicular reflective surfaces.

8. The spindle axial movement measuring device as claimed in claim 1, characterized in that, The light-shielding plate is slidably connected to the mounting base.

9. The spindle axial movement measuring device as claimed in claim 1, characterized in that, Both the connector and the fixing member include a fixing sleeve, an adjusting screw, an adjusting nut, and several claws. The adjusting screw is rotatably connected to the fixing sleeve, and the adjusting nut is housed within the fixing sleeve and threadedly connected to the adjusting screw. The adjusting nut has several inclined driving surfaces spaced circumferentially. Several claws are spaced circumferentially along the adjusting nut, with one end slidingly contacting several driving surfaces. The claws are slidably connected to the fixing sleeve, and the sliding direction of the claws is parallel to the radial direction of the adjusting screw. The corner cone reflector is fixed to one end of the fixing sleeve of the fixing member, and the sliding drive member is fixed to one end of the fixing sleeve of the connector.

Images