Internal gear m value measuring instrument and measuring method thereof

Abstract

This invention discloses an instrument and method for measuring the M-value of internal gears, belonging to the field of gear inspection technology. The instrument includes a base, a Z-axis lifting and adjusting platform, a measuring unit, a workpiece bearing assembly, and a control unit. The Z-axis lifting and adjusting platform drives the measuring unit to reciprocate vertically. The measuring unit includes an X-axis bidirectional synchronous drive mechanism, a middle slide plate, a force adjustment assembly, a probe mounting rod, a tooth profile feature recognition sensor, and a displacement detection assembly. The middle slide plate is floatingly mounted at the output end of the X-axis bidirectional synchronous drive mechanism. The force adjustment assembly applies a constant elastic force to the middle slide plate through an elastic element. The tooth profile feature recognition sensor scans the tooth profile and outputs tooth tip and root position signals. The displacement detection assembly detects the probe displacement in real time. The control unit controls the probe to automatically center based on the tooth profile recognition signal and adjusts the probe position in a closed loop based on the displacement feedback signal, achieving high-precision measurement of the M-value of internal gears.

Description

Technical Field

[0001] This invention relates to the field of measuring instrument technology, and in particular to an instrument for measuring the M value of internal gears and its measurement method. Background Technology

[0002] As a core component in precision transmission mechanisms, the M-value (pitch between gear teeth) of internal gears is a key parameter for evaluating tooth thickness accuracy. It directly determines the meshing backlash, transmission smoothness, and load-bearing capacity of the gear pair, and has important applications in industrial robots, precision machine tools, and automotive transmissions. Currently, the M-value of internal gears is mainly measured using the following methods: (1) Manual measurement method: The operator uses general measuring tools such as vernier calipers, micrometers or special length measuring instruments to manually insert two probes into the tooth groove of the internal gear. After adjusting the position of the probes multiple times to find the contact point of the tooth surface, the measurement value is read. However, after the probes are inserted into the narrow tooth groove of the internal gear, the tooth surface contact is not visible. The operator can only judge whether the probes are aligned with the tooth groove and whether they are in contact with both sides of the tooth surface by feel. The difference in the operating experience of different people leads to a large dispersion of measurement results. During the measurement process, the probes need to be manually supported to maintain the contact state while reading the value. It is difficult to ensure that the contact force is consistent for each measurement, resulting in poor repeatability. For large-size or heavy internal gears, manual flipping and adjustment are extremely laborious, resulting in low measurement efficiency.

[0003] (2) Special gear measuring instrument: Patent CN223711059U discloses a gear M-value measuring instrument, which uses a servo moving mechanism to push the gear into the measuring position and drives two probes to move towards each other to contact the tooth surface through a slide cylinder. The instrument is used in conjunction with a camera component to capture images of the tooth surface for auxiliary analysis. However, this measuring instrument does not solve the problem of tooth groove alignment in internal gear measurement. That is, the movement of the two probes towards each other is an open-loop control. The probes stop when they contact the tooth surface. Since the position of the tooth groove of the internal gear is unpredictable before the probes are inserted, it is impossible to confirm whether the probes accurately enter the center of the tooth groove or whether they contact both sides of the tooth surface at the same time. If the probes abut against the tooth tip or make oblique contact, it will directly lead to the distortion of the measurement value.

[0004] Therefore, in the existing internal gear M-value measurement technology, how to achieve automatic and accurate alignment between the probe and the internal gear tooth groove, how to ensure constant and controllable contact force for each measurement, and how to achieve automatic probe avoidance in a limited space to adapt to automated operation are still technical problems that urgently need to be solved. Summary of the Invention

[0005] The technical problem to be solved by the present invention is: in order to overcome the difficulties of the prior art, the present invention provides an instrument for measuring the M value of internal gears and a method for measuring it.

[0006] The technical solution adopted by this invention to solve its technical problem is: an instrument for measuring the M value of internal gears, comprising: Base, The Z-axis lifting adjustment platform is mounted on the machine base and is used to drive the measuring unit to reciprocate in the vertical direction. The measuring unit, installed at the output end of the Z-axis lifting adjustment platform, includes: The X-axis bidirectional synchronous drive mechanism has two output ends that move synchronously in opposite directions or in opposite directions along the X-axis direction; The sliding plate is floatingly mounted at the output end of the X-axis bidirectional synchronous drive mechanism. The force adjustment assembly applies an adjustable constant elastic force to the middle slide plate through an elastic element to provide the contact measurement force between the probe and the tooth surface; Two probe mounting rods are respectively set on the middle slide plate, and a probe is set at one end of each probe mounting rod; A tooth profile feature recognition sensor is mounted on at least one probe mounting rod to scan the tooth profile and output tooth tip position signal and tooth root position signal; And a displacement detection component, used to detect the actual displacement of the two probes in real time and output a displacement feedback signal; The workpiece support assembly is mounted on the machine base and located below the measuring unit, and is used to place and position the internal gear to be measured. The control unit is mounted on the machine base and is electrically connected to the Z-axis lifting adjustment platform, the X-axis bidirectional synchronous drive mechanism, the tooth profile feature recognition sensor, and the displacement detection component.

[0007] By identifying the tooth profile with sensors and combining it with displacement closed-loop feedback, the probe can be automatically aligned, solving the problem that the probe cannot automatically align with the center of the tooth groove in the existing technology; at the same time, a constant elastic force is applied to the sliding plate by the force adjustment component, providing structural protection for the constant control of the measurement force.

[0008] Furthermore, the force adjustment assembly includes a spring adjustment plate disposed on the measuring unit, a spring counter-pull plate disposed on the middle slide plate, and a compression spring and a compression spring adjustment screw disposed between the spring adjustment plate and the spring counter-pull plate; The spring counter-pull plate moves synchronously with the middle slide plate. The compression spring adjusting screw is threadedly connected to the spring counter-pull plate. One end of the compression spring abuts against the compression spring adjusting screw, and the other end abuts against the spring adjusting plate. Rotating the spring adjusting screw changes the pre-compression of the spring, thereby adjusting the elastic force on the sliding plate.

[0009] The pre-compression of the compression spring is changed by rotating the spring adjustment screw, thereby adjusting the measuring force. This ensures the constantness and repeatability of the contact force between the probe and the tooth surface in a purely mechanical way, solving the problem of large result dispersion caused by the operator's feel and inconsistent measuring force in the existing technology.

[0010] Furthermore, at least one probe mounting rod is a foldable probe mounting rod, which includes a probe mounting seat disposed on the middle slide plate, a servo motor disposed on the probe mounting seat, and a connecting plate connecting the servo motor output shaft and the probe. One end of the foldable probe mounting rod is rotatably mounted on the probe mounting seat via a rotating shaft. The servo motor drives the foldable probe mounting rod to rotate around the rotating shaft, thereby causing the probe to flip and switch between a horizontal measurement position and a vertical avoidance position.

[0011] The probe automatically flips over to avoid collisions with the workpiece during gear loading and unloading, which not only prevents the probe from being damaged by collisions, but also provides space for the docking robot to automatically load and unload materials.

[0012] Furthermore, the tooth profile feature recognition sensor is installed at the end of the foldable probe mounting rod, with the detection end of the tooth profile recognition sensor facing the tooth profile of the internal gear to be measured, and moving synchronously with the foldable probe mounting rod.

[0013] The sensor and the probe always maintain a fixed relative position. During the probe feeding process, the sensor first scans the tooth profile to provide the control unit with tooth tip and tooth root position data to calculate the tooth groove center.

[0014] Furthermore, the displacement detection component is a dual-head grating ruler displacement detection component, including a grating ruler arranged on the measuring unit along the X-axis and linked with the two probes, and two grating reading heads arranged opposite to the grating ruler; the grating ruler is arranged on the middle slide plate and moves synchronously with the middle slide plate, and the two grating reading heads are arranged on the marble base plate of the measuring unit; The output end of the X-axis bidirectional synchronous drive mechanism is connected to the large slide plate. The two ends of the movement path of the large slide plate are respectively equipped with travel limit switches. The large slide plate is equipped with limit sheet metal that cooperates with the travel limit switches. When the large slide plate moves to the limit position, the limit sheet metal triggers the travel limit switch to limit the extreme movement position of the two probes.

[0015] The grating ruler provides real-time feedback on the actual displacement of the two probes, and the limit sheet metal triggers the travel limit switch to limit the extreme movement positions of the two probes.

[0016] Furthermore, the workpiece bearing assembly is a manual workpiece bearing assembly, which includes a base plate, an intermediate plate, and a top plate stacked sequentially. The base plate is mounted on the machine base, and a cross roller guide is provided between the base plate and the intermediate plate to enable manual sliding adjustment. The top plate is provided with mutually perpendicular stop adjustment seats, and each stop adjustment seat is connected to a stop adjustment strip, which is used to abut against the outer peripheral wall of the internal gear to be measured from mutually perpendicular directions to complete manual centering and positioning.

[0017] Manual sliding adjustment is achieved through cross roller guides, and bidirectional abutment positioning of the gear's outer peripheral wall is achieved through mutually perpendicular stop adjustment seats and stop adjustment bars. It is suitable for single-piece and small-batch measurement scenarios, and the operation is intuitive and flexible.

[0018] Furthermore, the workpiece carrying assembly is an automatic workpiece carrying assembly, which includes: Support base The Y-axis centering adjustment mechanism is mounted on the support base and is used to drive the internal gear under test to move along the direction perpendicular to the X-axis in the horizontal plane to automatically correct the position of the internal gear under test. A sliding connector is installed at the output end of the Y-axis centering adjustment mechanism; A rotary indexing mechanism, mounted on a sliding connector, is used to drive the internal gear under test to rotate and index around its vertical axis. A fixture disk is installed at the output end of the rotary indexing mechanism, and the fixture disk is provided with a positioning slot for placing the internal gear to be tested.

[0019] The gear center is automatically corrected by the Y-axis centering adjustment mechanism, and the gear is automatically indexed and rotated by the rotary indexing mechanism.

[0020] Furthermore, the Y-axis centering adjustment mechanism includes a Y-axis guide rail disposed on the support base along the Y-axis direction, a Y-axis slide plate slidably disposed on the Y-axis guide rail, and a Y-axis drive motor disposed on the base. The Y-axis drive motor drives the Y-axis slide plate to reciprocate along the Y-axis direction via a lead screw.

[0021] The rotational motion of the rotary motor is converted into the linear reciprocating motion of the Y-axis slide through the lead screw, thereby realizing the automatic and precise correction of the gear in the Y-axis direction.

[0022] Furthermore, as the Z-axis lifting adjustment platform drives the measuring unit to move vertically to different tooth width sections, the X-axis bidirectional synchronous drive mechanism simultaneously drives the sliding plate to reciprocate horizontally, so as to realize continuous measurement of different tooth width sections of the internal gear. The control unit calculates the center position of the tooth groove based on the tooth tip position data and tooth bottom position data obtained by the tooth profile feature recognition sensor, and controls the X-axis bidirectional synchronous drive mechanism to drive the slide plate to move, so that the two probes are located at symmetrical measurement positions on both sides of the tooth groove center.

[0023] While the Z-axis is raised and lowered, the X-axis is fed synchronously to achieve continuous measurement of different tooth width sections; at the same time, the control unit is limited to calculate the center position of the tooth groove based on the tooth tip / tooth root data and drive the probe to center the control logic.

[0024] A method for measuring the M-value of an internal gear, using the internal gear M-value measuring instrument as described above, includes the following steps: S1. Tooth profile scanning: Control the X-axis bidirectional synchronous drive mechanism to drive the probe to move towards the internal gear to be measured, and at the same time scan the tooth profile through the tooth profile feature recognition sensor to obtain tooth tip position data and tooth root position data within at least one complete tooth pitch range. S2. Tooth groove center calculation: Based on the tooth tip position data and tooth root position data, calculate the offset of the tooth groove center relative to the initial position of the probe within the tooth pitch range, and determine the target symmetrical measurement position of the two probes accordingly. S3. Probe centering feed: Control the X-axis bidirectional synchronous drive mechanism to drive the two probes to move synchronously from both sides to the target symmetrical measurement position; S4, Constant Force Contact: Control the two probes to continue to feed slowly towards each other at the first speed until the position detection switch of the force adjustment component is triggered, confirming that the probes are in contact with the tooth surface with the set constant measuring force, and then stop feeding; S5. Displacement Measurement and Feedback: The actual displacement of the two probes is read and recorded in real time through the displacement detection component; S6. Multi-point measurement of tooth surface: Control the rotary indexing mechanism or manually drive the internal gear under test to rotate by a preset angle, and repeat steps S1 to S5 until the preset number of tooth groove positions are measured. S7, M value calculation: Calculate and output the M value of the internal gear under test based on the displacement measurement values ​​of each measurement.

[0025] The sensor identifies the tooth profile and calculates the tooth groove center, solving the technical problem of blind probe feeding and inability to align with the tooth groove in the existing technology; the contact force is kept constant by the position detection switch, which solves the problem of inconsistent force in manual measurement; the multi-point measurement steps combined with the rotary indexing mechanism realize full-circumference multi-section measurement, which solves the problem of insufficient representativeness of single measurement.

[0026] The beneficial effects of this invention are: By using a tooth profile feature recognition sensor installed on the probe mounting rod, the tooth profile is scanned synchronously during the probe feeding process, and the tooth tip position and tooth root position signals are output. The control unit calculates the tooth groove center position based on this and drives the two probes to move synchronously from both sides to the symmetrical measurement position, so as to realize the automatic and accurate centering of the probe. An adjustable constant elastic force is applied to the middle slide plate by a force adjustment component. The compression spring continuously applies a constant elastic force to the middle slide plate, which is transmitted to the probe through the middle slide plate. This ensures that the probe applies the exact same measuring force each time it contacts the tooth surface. At the same time, an elastic pressing position detection switch confirms whether the probe contacts the tooth surface with the set measuring force, avoiding measurement deviations caused by insufficient or excessive contact force, thus improving the repeatability and consistency of the measurement results. A grating ruler is set on the measuring unit along the X-axis, and grating reading heads are set at the two probes respectively. The actual displacement of the two probes is detected in real time and fed back to the control unit. The control unit sends a compensation control signal to the X-axis bidirectional synchronous drive mechanism accordingly to form a full closed-loop position control. The probe mounting rod is driven by a servo motor set on the middle slide to rotate around the pivot, so that the probe can automatically switch between the horizontal measurement position and the vertical clearance position. When the gear is loaded or unloaded, the probe automatically flips up to make room for operation, and automatically flips back to the working position when measuring. By setting two optional load-bearing components, the same device can be compatible with both manual and automatic modes. The manual load-bearing component achieves quick manual positioning through cross roller guides and stop adjustment bars, which is suitable for laboratory research and development and small-batch trial production scenarios. The automatic load-bearing component achieves automatic gear correction and automatic indexing through Y-axis centering adjustment mechanism and rotary indexing mechanism. With the help of a robot, it can realize unmanned fully automatic measurement, which is suitable for online inspection on mass production lines. By coordinating the Z-axis lifting adjustment platform and the X-axis bidirectional synchronous drive mechanism to operate simultaneously, the probe feeds synchronously in the horizontal direction as the measuring unit moves vertically to different tooth width sections, thereby achieving continuous automatic measurement of the M value of different tooth width sections. This not only improves measurement efficiency but also avoids positioning reference deviations introduced by multiple clamping operations. Attached Figure Description

[0027] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0028] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the present invention.

[0029] Figure 2 This is a schematic diagram of the Z-axis lifting and adjusting platform in Embodiment 1 of the present invention.

[0030] Figure 3 This is a schematic diagram of the measurement unit in Embodiment 1 of the present invention.

[0031] Figure 4 yes Figure 3 A schematic diagram of the bidirectional synchronous drive mechanism for the X-axis.

[0032] Figure 5 yes Figure 3 A schematic diagram of the structure of the force adjustment component.

[0033] Figure 6 yes Figure 3 A schematic diagram of the structure of the foldable probe mounting rod.

[0034] Figure 7 yes Figure 3 A schematic diagram of the displacement detection component.

[0035] Figure 8 This is a schematic diagram of the structure of the manual workpiece bearing assembly in Embodiment 1 of the present invention.

[0036] Figure 9 This is a schematic diagram of the automatic workpiece carrying assembly in Embodiment 2 of the present invention.

[0037] Figure 10 This is a flowchart of Embodiment 3 of the present invention.

[0038] In the diagram: 1. Machine base; 2. Z-axis lifting adjustment platform; 3. Measuring unit; 4. Workpiece bearing assembly; 5. Control unit; 6. Internal gear to be measured; 7. Marble sheet metal cover; 71. Notch; 8. Y-axis centering adjustment mechanism; 21. Vertical plate; 22. Z-axis ball screw pair; 23. Z-axis linear guide; 231. Slider; 24. Lifting drive motor; 241. Motor base; 25. Measuring assembly connecting plate; 251. Limit rod; 26. Scale photoelectric guide rail; 27. Photoelectric switch; 28. Pointer; 29. ​​Lifting cover; 291. Limiting groove; 31. Marble base plate; 32. X-axis bidirectional synchronous drive mechanism; 321. Bidirectional lead screw support; 322. X-axis bidirectional lead screw; 3221. First threaded section; 3222. Second threaded section; 323. X-axis drive motor; 324. X-axis slide rail; 3251. First slider; 3252. Second slider; 33. Large sliding plate; 331. First large sliding plate; 332. Second large sliding plate; 3311. Polyurethane limiting block; 3312. Hard stop limiting block; 3313. Limiting sheet metal; 34. Middle sliding plate; 341. First middle sliding plate; 342. Second middle sliding plate; 343. Middle sliding plate positioning sheet metal; 344. Photoelectric sensor; 35. Force adjustment assembly; 351. Spring adjustment plate; 352. Spring 353. Reverse pull plate; 354. Compression spring; 36. Compression spring adjusting screw; 37. Probe mounting rod; 38. Probe mounting base; 39. Servo motor; 30. Connecting plate; 31. Displacement detection assembly; 32. Grating ruler; 33. First grating reading head; 34. Second grating reading head; 35. First reading head bracket; 36. Second reading head bracket; 37. Travel limit switch; 48. Base plate; 49. Impact block; 40. Intermediate plate; 41. First groove; 42. Limit fixing block; 43. Top plate; 44. Second groove; 45. First stop adjusting seat; 46. Second stop adjusting seat; 47. First stop adjusting strip; 48. Second stop adjusting strip; 49. Cross roller guide rail; 40. Bearing base; 41. Sliding connector; 49. Rotary indexing mechanism; 491. Rotary motor; 410. Fixture plate; 4101. Positioning slot; 412. Oil-proof plate; 81. Y-axis guide rail; 82. Y-axis slide plate; 83. Y-axis drive motor; 84. Lead screw. Detailed Implementation

[0039] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, illustrating only the basic structure of the invention, and therefore only show the components relevant to the invention.

[0040] Example 1: like Figure 1 As shown, this embodiment provides an instrument for measuring the M value of internal gears, including a base 1, a Z-axis lifting and adjusting platform 2, a measuring unit 3, a workpiece bearing assembly 4, and a control unit 5. The base 1 is made of marble, which has high rigidity, low thermal expansion coefficient, and excellent vibration reduction performance. It can effectively suppress the influence of external vibration on the measurement accuracy during the measurement process and provide a stable installation reference for each functional mechanism.

[0041] The Z-axis lifting adjustment platform 2 is mounted on the rear side of the base 1 and is used to drive the measuring unit 3 to reciprocate along the vertical direction (Z-axis direction). The measuring unit 3 is mounted on the output end of the Z-axis lifting adjustment platform 2, located above the base 1. The workpiece bearing assembly 4 is mounted on the base 1 and located below the measuring unit 3, and is used to place and position the internal gear 6 to be measured. The control unit 5 is located on the side of the base 1 and is electrically connected to the driving components and sensors in the Z-axis lifting adjustment platform 2 and the measuring unit 3.

[0042] The measuring unit 3 is covered by a marble sheet metal cover 7, which serves to protect the precision components inside the measuring unit 3 from dust and oil. A notch 71 extending along the X-axis is provided on the marble sheet metal cover 7 at a position corresponding to the probe. The notch 71 provides clearance for the probe and probe mounting rod to move back and forth horizontally during measurement, ensuring that the probe is not interfered with by the cover when moving in opposite directions.

[0043] like Figure 2As shown, the Z-axis lifting adjustment platform 2 includes a vertical plate 21, a Z-axis ball screw pair 22, two Z-axis linear guides 23, a lifting drive motor 24, and a measuring component connecting plate 25. The vertical plate 21 is vertically fixed to the rear edge of the base 1. The Z-axis ball screw pair 22 is vertically mounted at the center of the front side of the vertical plate 21, and its upper end is connected to the output shaft of the lifting drive motor 24 via a coupling. The lifting drive motor 24 is fixed to the top of the vertical plate 21 via a motor base 241. The lifting drive motor 24 is preferably a servo motor, which integrates an encoder to provide real-time feedback on the motor's rotation angle and speed. The two Z-axis linear guides 23 are respectively located on the left and right sides of the Z-axis ball screw pair 22, and each Z-axis linear guide 23 has a slider 231 slidably mounted on it. The back of the measuring component connecting plate 25 is connected to both the screw nut of the Z-axis ball screw pair 22 and each slider 231. When the lifting drive motor 24 drives the Z-axis ball screw pair 22 to rotate, the screw nut moves along the screw axis, causing the measuring component connecting plate 25 to make a smooth vertical lifting motion along the two Z-axis linear guide rails 23.

[0044] The side wall of the upright plate 21 is equipped with a scale photoelectric guide rail 26, which extends vertically. A photoelectric switch 27 is mounted on the scale photoelectric guide rail 26, and its position can be adjusted by sliding along the guide rail. A pointer 28 pointing to the photoelectric switch 27 is connected to the side wall of the measuring component connecting plate 25. The operator can accurately read the current vertical position of the measuring component connecting plate 25 by using the pointer 28 in conjunction with the photoelectric switch 27, and set the photoelectric switch 27 to a preset measuring height. When the measuring component connecting plate 25 is raised or lowered to this position, the pointer 28 triggers the photoelectric switch 27, sending a position signal to the control unit 5, thereby achieving automatic positioning of the Z-axis lifting position. The Z-axis lifting adjustment platform 2 is covered by a lifting cover 29, which provides dust protection and protection for precision components such as the Z-axis ball screw pair 22 and the Z-axis linear guide rail 23.

[0045] like Figure 3As shown, the measuring unit 3 is installed at the output end of the Z-axis lifting adjustment platform 2, that is, connected to the front side of the measuring component connecting plate 25. In this embodiment, the two output ends of the X-axis bidirectional synchronous drive mechanism 32 are the first large slide plate 331 and the second large slide plate 332. The first large slide plate 331 and the second large slide plate 332 are respectively connected to the first threaded section 3221 and the second threaded section 3222 of the X-axis bidirectional lead screw 322 through lead screw nuts. Under the drive of the X-axis drive motor 323, they move synchronously in opposite directions or in opposite directions along the X-axis slide rail 324. The middle slide plate 34 (including the first middle slide plate 341 and the second middle slide plate 342) is floatingly set on the corresponding large slide plate 33 through the cross roller guide rail. As the direct bearing component of the probe mounting rod 36, it can elastically float relative to the large slide plate 33 in the X-axis direction under the action of the force adjustment component 35. The measuring unit 3 includes a marble substrate 31, an X-axis bidirectional synchronous drive mechanism 32, a large sliding plate 33, a medium sliding plate 34, a force adjustment component 35, two probe mounting rods 36, a tooth profile feature recognition sensor (not shown in the figure), and a displacement detection component 38. The back side of the marble substrate 31 is connected to the front side of the measuring component connecting plate 25. The X-axis bidirectional synchronous drive mechanism 32, the force adjustment component 35, and the displacement detection component 38 are all mounted on the marble substrate 31.

[0046] like Figure 4 As shown, the X-axis bidirectional synchronous drive mechanism 32 includes a bidirectional lead screw support 321, an X-axis bidirectional lead screw 322, an X-axis drive motor 323, and a pair of X-axis slide rails 324. The bidirectional lead screw support 321 is fixed to the front side of the marble substrate 31, and the X-axis bidirectional lead screw 322 is rotatably mounted in the bidirectional lead screw support 321 via bearings. The X-axis bidirectional lead screw 322 has two sections of threads with opposite directions of rotation, namely a first thread section 3221 and a second thread section 3222. The first thread section 3221 is a right-hand thread, and the second thread section 3222 is a left-hand thread; or the first thread section 3221 is a left-hand thread, and the second thread section 3222 is a right-hand thread. When the X-axis bidirectional lead screw 322 rotates in a certain direction, the two lead screw nuts meshing with the first thread section 3221 and the second thread section 3222 respectively move synchronously in opposite directions, thereby realizing the synchronous movement of the two output ends in opposite directions along the X-axis.

[0047] The X-axis drive motor 323 is fixed to the front side of the marble substrate 31 via a motor mount, and is positioned at the midpoint of the X-axis bidirectional lead screw 322 along its length. The X-axis drive motor 323 is preferably a hollow shaft servo motor with a hollow rotor shaft through which the X-axis bidirectional lead screw 322 passes and is connected for transmission. The two ends of the hollow shaft servo motor are adjacent to the first threaded section 3221 and the second threaded section 3222 of the X-axis bidirectional lead screw 322, respectively. When the X-axis drive motor 323 rotates, it directly drives the X-axis bidirectional lead screw 322 to rotate synchronously, ensuring the synchronicity and transmission accuracy of the outputs at both ends of the lead screw.

[0048] The X-axis slide rail 324 is fixed to the front side of the marble substrate 31 along the X-axis direction and is located on the upper and lower sides of the X-axis bidirectional lead screw 322. Figure 7 As shown, a first slider 3251 and a second slider 3252 are slidably mounted on the X-axis slide rail 324. There are two large slide plates 33, namely a first large slide plate 331 and a second large slide plate 332. The first large slide plate 331 is fixedly connected to the first slider 3251, and the second large slide plate 332 is fixedly connected to the second slider 3252. The first large slide plate 331 is driven by a lead screw nut to the first threaded section 3221 of the X-axis bidirectional lead screw 322, and the second large slide plate 332 is driven by a lead screw nut to the second threaded section 3222 of the X-axis bidirectional lead screw 322. When the X-axis drive motor 323 drives the X-axis bidirectional lead screw 322 to rotate, the first large slide plate 331 and the second large slide plate 332 move synchronously towards or away from each other along the X-axis slide rail 324.

[0049] The outer ends of the large sliding plate 33 (i.e., the left end of the first large sliding plate 331 and the right end of the second large sliding plate 332) are respectively connected to hard stop blocks 3312 via polyurethane limit blocks 3311. The hard stop blocks 3312 are disposed opposite to the end face of the marble substrate 31. When the large sliding plate 33 moves to its limit position, the hard stop blocks 3312 abut against the end face of the marble substrate 31, forming a mechanical hard limit to prevent the large sliding plate 33 from exceeding the safe travel range. The upper end face of the large sliding plate 33 is connected to a limit sheet metal 3313, which is used to achieve soft limit protection in conjunction with photoelectric sensors at the electrical level.

[0050] There are two intermediate slide plates 34, namely the first intermediate slide plate 341 and the second intermediate slide plate 342. The first intermediate slide plate 341 is mounted on the first large slide plate 331 via a cross roller guide, and the second intermediate slide plate 342 is mounted on the second large slide plate 332 via a cross roller guide. Each intermediate slide plate 34 can slide relative to the corresponding large slide plate 33 along the X-axis. Two probe mounting rods 36 are respectively mounted on the first intermediate slide plate 341 and the second intermediate slide plate 342, and a probe (not shown in the figure) is mounted at one end of each probe mounting rod 36.

[0051] like Figure 5As shown, the force adjustment assembly 35 is disposed on each intermediate slide plate 34, and applies an adjustable constant elastic force to the corresponding intermediate slide plate 34 through an elastic element to provide the contact measurement force between the probe and the tooth surface. Each force adjustment assembly 35 includes a spring adjustment plate 351, a spring counter-pull plate 352, a compression spring 353, and a compression spring adjustment screw 354. The spring adjustment plate 351 is fixed to the outer end face of the corresponding first large slide plate 331 or second large slide plate 332 by bolts, and a guide hole is provided on the spring adjustment plate 351. The spring counter-pull plate 352 has an L-shaped structure, and its horizontal section is fixed at the end of the corresponding first intermediate slide plate 341 or second intermediate slide plate 342, moving synchronously with the intermediate slide plate 34. The spring adjusting screw 354 is threaded to the vertical section of the spring counter-pull plate 352. One end of the compression spring 353 is sleeved on the end of the spring adjusting screw 354 and abuts against the spring counter-pull plate 352. The other end of the compression spring 353 passes through the guide hole of the spring adjusting plate 351 and abuts against the spring adjusting plate 351.

[0052] One end of the spring counter-pull plate 352 is connected to the end of the middle slide plate 34, and the other end is connected to one end of the compression spring adjusting screw 354 via a hand-tightened stepped screw. The other end of the compression spring adjusting screw 354 is connected to one end of the compression spring 353. When the compression spring adjusting screw 354 is rotated, it moves axially relative to the spring counter-pull plate 352, thereby changing the pre-compression of the compression spring 353. When the compression spring 353 extends, the elastic force it exerts on the spring counter-pull plate 352 increases, and the spring counter-pull plate 352 pushes the middle slide plate 34 to move outward relative to the large slide plate 33, allowing the probe to contact the tooth surface with a greater measuring force. When the compression spring 353 shortens, the elastic force decreases, the measuring force decreases, and the measuring force is quantitatively adjusted to ensure that each measurement is performed with the same constant measuring force.

[0053] The end of the middle slide plate 34 is connected to a middle slide plate positioning sheet metal 343. Photoelectric sensors 344 are respectively installed on the first large slide plate 331 and the second large slide plate 332. The photoelectric sensors 344 work in conjunction with the middle slide plate positioning sheet metal 343 to detect whether the middle slide plate 34 has moved to a preset measurement starting position or limit position. When the large slide plate 33 moves towards the gear direction under the drive of the X-axis bidirectional synchronous drive mechanism 32, the middle slide plate 34 moves synchronously with the large slide plate 33. When the probe contacts the tooth surface, the middle slide plate 34 experiences a reaction force from the tooth surface and floats backward relative to the large slide plate 33. The compression spring 353 is compressed, and the middle slide plate positioning sheet metal 343 moves backward with the middle slide plate 34. When the elastic force of the compression spring 353 reaches a set value, the middle slide plate positioning sheet metal 343 triggers the photoelectric sensor 344, sending a positioning signal to the control unit 5, indicating that the probe has reliably contacted the tooth surface with the set measuring force. This structure ensures that data is read under the same contact force conditions for each measurement, avoiding measurement deviations caused by insufficient or excessive contact force.

[0054] like Figure 3 and Figure 6 As shown, two probe mounting rods 36 are respectively mounted on the first intermediate slide plate 341 and the second intermediate slide plate 342. In this embodiment, one of the probe mounting rods 36 is a foldable probe mounting rod. The foldable probe mounting rod includes a probe mounting base 362, a servo motor 363, a connecting plate 364, and a rotating shaft. The probe mounting base 362 is fixed to the outer surface of the intermediate slide plate 34. The servo motor 363 is fixedly mounted on the outer side wall of the probe mounting base 362. The output shaft of the servo motor 363 extends horizontally. One end of the connecting plate 364 is connected to the output shaft of the servo motor 363, and the extension of the connecting plate 364 is connected to the probe mounting rod 36. A probe is mounted on the end of the probe mounting rod 36. The probe mounting rod 36 is rotatably mounted on the probe mounting base 362 via the rotating shaft.

[0055] When the servo motor 363 drives the connecting plate 364 to rotate around its output shaft, the connecting plate 364 drives the probe mounting rod 36 to rotate synchronously around the axis. When the servo motor 363 rotates forward, the probe mounting rod 36 flips upward around the axis, causing the probe to switch from a horizontal measuring position to a vertical clearance position. At this time, the probe is lifted up and away from the gear space, providing unobstructed operating space for gear loading and unloading. When the servo motor 363 rotates in the reverse direction, the probe mounting rod 36 flips downward around the axis to reset, and the probe switches from the vertical clearance position to the horizontal measuring position, entering the measurement state. The foldable probe mounting rod structure effectively avoids collision between the probe and the gear 6 to be measured during gear loading and unloading, and at the same time provides conditions for the docking robot to realize automated loading and unloading.

[0056] like Figure 3 As shown, the tooth profile feature recognition sensor is mounted on the foldable probe mounting rod. In this embodiment, the tooth profile feature recognition sensor is mounted at the end of the foldable probe mounting rod 36, with its detection end facing the tooth profile direction of the internal gear 6 to be measured. The tooth profile feature recognition sensor moves synchronously with the foldable probe mounting rod. During the process of the probe feeding towards the tooth groove, the tooth profile feature recognition sensor first scans the tooth profile to obtain the position data of the tooth tip and tooth root.

[0057] Tooth profile feature recognition sensors can be either laser displacement sensors or contact displacement sensors. Laser displacement sensors measure the distance between the sensor's detection end and the tooth profile surface by emitting a laser beam and receiving the reflected light, offering advantages such as non-contact operation and fast response. Contact displacement sensors, on the other hand, acquire position data by having a probe contact the tooth profile surface, offering the advantage of high accuracy. The operator can select the appropriate sensor type based on the accuracy requirements and surface condition of the gear being measured.

[0058] The control unit 5 is pre-installed with a tooth profile analysis module. Tooth tip and root position data obtained by the tooth profile feature recognition sensor are transmitted to the control unit 5. Based on the tooth tip and root position data within a complete tooth pitch range, the tooth profile analysis module plots a tooth profile waveform, identifies the lowest point between adjacent tooth tips as the root position, and takes the midpoint between two adjacent root positions as the theoretical position of the tooth groove center. Based on this, it calculates the offset of the tooth groove center relative to the initial position of the probe and determines the target symmetrical measurement positions of the two probes. The control unit 5 then controls the X-axis bidirectional synchronous drive mechanism 32 to move the two probes to the symmetrical measurement positions on both sides of the tooth groove center based on these target symmetrical measurement positions.

[0059] like Figure 3 and Figure 7 As shown, the displacement detection component 38 is a dual-head grating ruler displacement detection component, including a grating ruler 381, a first grating reading head 382, ​​and a second grating reading head 383. The grating ruler 381 is connected to the middle slider 34 along the X-axis direction. The grating ruler 381 is a high-precision micron-level measuring ruler with equally spaced scale lines engraved on it, providing a reference for displacement measurement. The first grating reading head 382 and the second grating reading head 383 are respectively linked to two probes. Specifically, the first grating reading head 382 is fixed to the top surface of the marble substrate 31 by a first reading head bracket 384; the second grating reading head 383 is fixed to the top surface of the marble substrate 31 by a second reading head bracket 385. Both the first grating reading head 382 and the second grating reading head 383 are arranged opposite to the grating ruler 381 and maintain a standard detection gap.

[0060] As the two probes move during the measurement process, the first grating reading head 382 and the second grating reading head 383 read the scale value on the grating ruler 381 respectively, detect the actual displacement of the two probes in real time, and send the displacement feedback signal to the control unit 5. The control unit 5 is equipped with a displacement closed-loop control module. This module compares the received displacement feedback signal with the preset target displacement value. When there is a deviation between the actual displacement and the target displacement, a compensation control signal is sent to the X-axis drive motor 323 to drive the first large slide plate 331 and the second large slide plate 332 to move synchronously to the target position, forming a full closed-loop position control.

[0061] The large sliding plate 33 on the marble substrate 31 has travel limit switches 392 at both ends of its movement path to limit the extreme movement positions of the two probes. When the large sliding plate 33 moves to its extreme position, the limit sheet metal 3313 triggers the travel limit switch 392, and the control unit 5 immediately stops the X-axis drive motor 323 to prevent the probe from exceeding the safe travel range.

[0062] like Figure 8As shown, the workpiece bearing assembly 4 is a manual workpiece bearing assembly, including a base plate 41, an intermediate plate 42, and a top plate 43. The base plate 41 is fixed to the upper end face of the machine base 1. A cross roller guide 44 is provided between the base plate 41 and the intermediate plate 42. The intermediate plate 42 can be manually slidable relative to the base plate 41 along the X-axis direction via the cross roller guide 44. The cross roller guide 44 features high precision, high rigidity, and low friction, enabling it to withstand the weight of the gears and ensure smooth sliding.

[0063] An impact block 411 is fixed to the upper end face of the base plate 41. A first groove 421 extending in the sliding direction is formed on the lower end face of the intermediate plate 42 corresponding to the position of the impact block 411. Limiting blocks 422 are respectively installed at both ends of the first groove 421. The two limiting blocks 422 are used to cooperate with the impact block 411 to limit the sliding stroke of the intermediate plate 42. When the intermediate plate 42 slides to the end of the stroke, the impact block 411 abuts against the corresponding limiting block 422 to prevent the intermediate plate 42 from dislodging from the cross roller guide 44. The top plate 43 is fixedly connected to the upper end face of the intermediate plate 42. A second groove 431 is formed on the top plate 43 corresponding to the position of the first groove 421. The second groove 431 provides clearance space for the placement of the gear, so that the gear can be placed stably on the upper end face of the top plate 43.

[0064] The top plate 43 is equipped with a first stop adjustment seat 432 and a second stop adjustment seat 433. The first stop adjustment seat 432 is adjustablely mounted on the top plate 43 along the X-axis, and the second stop adjustment seat 433 is adjustablely mounted on one side of the first stop adjustment seat 432 along the Y-axis. The first stop adjustment seat 432 and the second stop adjustment seat 433 are perpendicularly distributed. A first stop adjustment strip 434 is connected to the first stop adjustment seat 432, and a second stop adjustment strip 435 is connected to the second stop adjustment seat 433. The operator manually pushes the intermediate plate 42 to slide along the X-axis while simultaneously adjusting the positions of the first stop adjustment seat 432 and the second stop adjustment seat 433, so that the first stop adjustment strip 434 and the second stop adjustment strip 435 abut against the outer peripheral wall of the internal gear 6 to be tested from two mutually perpendicular directions, thus completing the manual centering and positioning of the gear.

[0065] The work process is as follows: The internal gear 6 to be measured is placed on the top plate 43. By manually pushing the intermediate plate 42 and adjusting the first stop adjustment bar 434 and the second stop adjustment bar 435, the gear is aligned and positioned against the outer peripheral wall from two mutually perpendicular directions. The control unit 5 controls the lifting drive motor 24 to drive the Z-axis ball screw pair 22 to rotate. The measuring component connecting plate 25 is raised and lowered along the Z-axis linear guide rail 23 to the preset measuring height position. The pointer 28 triggers the photoelectric switch 27, sending a position signal to the control unit 5. The control unit 5 controls the X-axis bidirectional synchronous drive mechanism 32 to drive the two probes to move towards the gear. During this process, the tooth profile feature recognition sensor scans the tooth profile to obtain the tooth tip and tooth root position data and transmits it to the control unit 5. After calculating the tooth groove center position, the control unit 5 controls the two probes to move to the symmetrical measuring positions on both sides of the tooth groove center. The two probes continue to slowly feed towards each other until the middle slide plate is in place. The sheet metal 343 triggers the photoelectric sensor 344 to confirm that the probe is in contact with the tooth surface with a constant measuring force. The grating ruler 381 and the grating reading head read the current displacement and feed it back to the control unit 5, recording the measurement value. The operator manually rotates the gear to the next measurement position, repeating the above steps until all measurements are completed. The control unit 5 calculates and outputs the internal gear M value based on each measurement value.

[0066] Example 2: like Figure 9 As shown, the difference from Embodiment 1 is that the workpiece bearing assembly 4 is an automatic workpiece bearing assembly. The automatic workpiece bearing assembly includes a Y-axis centering adjustment mechanism 8, a bearing base 46, a sliding connector 47, a servo screw motor 48, a rotary indexing mechanism 49, and a fixture disk 410. The Y-axis centering adjustment mechanism 8 is mounted on the bearing base 46 and is used to drive the internal gear 6 to be tested to move along the horizontal plane in a direction perpendicular to the Y-axis (i.e., the Z-axis direction) to automatically correct the position of the internal gear 6 to be tested. The Y-axis centering adjustment mechanism 8 includes a Y-axis guide rail 81 mounted on the upper surface of the base 1 along the Y-axis direction, a Y-axis slide plate 82 slidably mounted on the Y-axis guide rail 81, and a Y-axis drive motor 83 mounted on the bearing base 46. The Y-axis drive motor 83 is connected to the Y-axis slide plate 82 via a screw 84. When the Y-axis drive motor 83 rotates, it drives the Y-axis slide plate 82 to reciprocate along the Y-axis direction via the screw 84.

[0067] The sliding connector 47 is connected to the upper end face of the Y-axis slide plate 82 and moves synchronously with the Y-axis slide plate 82. The servo screw motor 48 is mounted on the support base 46. The screw of the servo screw motor 48 extends along the Y-axis direction and passes through the sliding connector 47. The screw nut of the servo screw motor 48 is fixedly connected to the end face of the sliding connector 47. When the servo screw motor 48 drives its screw to rotate, the screw nut drives the sliding connector 47 to reciprocate along the Y-axis guide rail 81.

[0068] A rotary indexing mechanism 49 is mounted on a sliding connector 47. The rotary indexing mechanism 49 includes a rotary motor 491, the output shaft of which extends vertically upward. The rotary motor 491 is preferably a servo motor with an integrated encoder for precise control of the rotation angle. A fixture disk 410 is fixedly connected to the upper end of the output shaft of the rotary motor 491 and rotates synchronously with it. The upper surface of the fixture disk 410 has a positioning slot 4101 for placing the internal gear 6 to be tested. The shape of the positioning slot 4101 matches the shape of the gear, achieving initial positioning of the gear. An oil-proof disk 412 is fitted around the lower outer periphery of the fixture disk 410. The oil-proof disk 412 is fixedly fitted around the outer periphery of the rotary motor 491 and located below the fixture disk 410, serving to collect oil dripping from the internal gear 6 to be tested, preventing oil contamination of the rotary motor 491 and the guide rail components below it.

[0069] The working principle of the automatic workpiece carrying assembly is as follows: The internal gear 6 to be measured is placed in the positioning slot 4101 of the fixture disk 410. The control unit 5 controls the Y-axis drive motor 83 to start, which drives the Y-axis slide plate 82 to move along the Y-axis direction through the lead screw 84, so that the gear on the fixture disk 410 is automatically corrected along the Y-axis direction to the measurement position aligned with the probe. During the measurement process, the control unit 5 controls the rotary motor 491 of the rotary indexing mechanism 49 to drive the fixture disk 410 to rotate by a preset angle, which drives the gear to automatically index and rotate around its vertical axis to the next measurement position, so as to realize automatic measurement of multiple points around the entire circumference.

[0070] The automatic workpiece bearing assembly in this embodiment can be used with an external robot to achieve fully automatic loading and unloading. When the gear is loading and unloading, the probe mounting rod 36 is automatically rotated to a vertical clearance position by the servo motor 363, which makes room for the robot to operate and realizes unmanned fully automatic measurement.

[0071] Example 3: like Figure 10 As shown, this embodiment provides a measurement method for an internal gear M-value measuring instrument, using the internal gear M-value measuring instrument as described in Embodiment 1 or Embodiment 2, including the following steps: S1. Tooth profile scanning: The control unit 5 controls the X-axis bidirectional synchronous drive mechanism 32 to drive the probe to move towards the internal gear 6 to be measured. At the same time, the tooth profile is scanned by the tooth profile feature recognition sensor set on the probe mounting rod 36 to obtain tooth tip position data and tooth root position data within at least one complete tooth pitch range.

[0072] Specifically, the control unit 5 sends a control signal to the X-axis drive motor 323, which drives the X-axis bidirectional lead screw 322 to rotate, causing the first large slide plate 331 and the second large slide plate 332 to move synchronously towards the gear direction along the X-axis. The probe on the probe mounting rod 36 feeds synchronously with the middle slide plate 34. The tooth profile feature recognition sensor scans the tooth profile before the probe contacts the tooth surface. When the tooth profile feature recognition sensor is a laser displacement sensor, it emits a laser beam to the tooth profile surface, receives the reflected light, and measures the distance. As the probe feeds continuously, the sensor continuously collects the distance data of each point on the tooth profile surface, forming a tooth profile scanning waveform. During the scanning process, the control unit 5 records the correspondence between the probe's feed position and the position of the tooth profile surface detected by the sensor.

[0073] S2. Tooth groove center calculation: The control unit 5 calculates the offset of the tooth groove center relative to the initial position of the probe within the tooth pitch range based on the tooth tip position data and tooth root position data, and determines the target symmetrical measurement position of the two probes accordingly.

[0074] Specifically, the tooth profile analysis module within the control unit 5 receives tooth profile scanning data transmitted by the tooth profile feature recognition sensor. This data consists of a series of discrete point data, each including the probe's feed coordinates at that position and the distance value of the tooth profile surface detected by the sensor. The tooth profile analysis module filters and fits the scanning data to generate a continuous tooth profile waveform. The lowest point between adjacent tooth tips in the waveform is identified as the tooth root position. Since the tooth tip in the tooth profile waveform corresponds to the tooth tip circle position of the gear, and the tooth root corresponds to the bottom position of the tooth groove, the midpoint between two adjacent tooth root positions is taken as the theoretical position of the tooth groove center. Because the tooth surfaces on both sides of the tooth groove are symmetrical with respect to the tooth groove center, the midpoint between two adjacent tooth roots is the tooth groove center. Based on the difference between the theoretical position of the tooth groove center and the initial position of the probe, the distance that each probe needs to move is calculated to obtain the target symmetrical measurement position of the two probes.

[0075] S3, Probe centering feed: Control unit 5 controls X-axis bidirectional synchronous drive mechanism 32 to drive two probes to move synchronously from both sides to the target symmetrical measurement position, so that the two probes are located on the outer sides of the tooth surface on both sides of the same tooth groove.

[0076] Specifically, the control unit 5 sends a control signal to the X-axis drive motor 323, which drives the X-axis bidirectional lead screw 322 to rotate. Since the X-axis bidirectional lead screw 322 has two threads with opposite directions of rotation, the first large slide plate 331 and the second large slide plate 332 move synchronously towards each other from both sides. The force adjustment component 35 set on the first large slide plate 331 pushes the first middle slide plate 341, and the force adjustment component 35 set on the second large slide plate 332 pushes the second middle slide plate 342, so that the probes at the ends of the two middle slide plates 34 move synchronously towards the center of the tooth groove. When the two probes reach the target symmetrical measurement position calculated in step S2, the two probes are located on the outer sides of the tooth surface on both sides of the same tooth groove and a small gap is maintained between them and the tooth surface. At this time, the probes have not yet contacted the tooth surface.

[0077] S4, Constant Force Contact: The control unit 5 controls the two probes to continue to feed slowly toward each other at the first speed until the position detection switch of the force adjustment component 35 is triggered, confirming that the probes are in contact with the tooth surface with the set constant measuring force, and the X-axis bidirectional synchronous drive mechanism 32 stops feeding.

[0078] Specifically, the control unit 5 controls the X-axis drive motor 323 to drive the X-axis bidirectional lead screw 322 to rotate slowly at a low speed. The two probes continue to feed towards each other at a first speed (e.g., 0.5 mm / s). When the probes contact the tooth surface, due to the continued feeding of the probes, the middle slide plate 34 is subjected to the reaction force from the tooth surface and floats backward relative to the large slide plate 33. The spring counter-pull plate 352 fixed at the end of the middle slide plate 34 moves synchronously with the middle slide plate 34, and the compression spring 353 is further compressed, increasing the elastic force. When the elastic force of the compression spring 353 reaches the set measurement force value, the middle slide plate positioning sheet metal 343 triggers the photoelectric sensor 344, which sends a positioning signal to the control unit 5. After receiving the signal, the control unit 5 immediately stops the X-axis drive motor 323, and the probes remain in this position. At this time, the probes contact the tooth surface with a set constant measurement force, the magnitude of which is determined by the preset position of the compression spring adjusting screw 354.

[0079] S5. Displacement Measurement and Feedback: The displacement detection component 38 reads the actual displacement of the two probes in real time and feeds it back to the control unit 5, which records the displacement measurement value.

[0080] Specifically, after the probe stops feeding, the first grating reading head 382 and the second grating reading head 383 read the scale value on the grating ruler 381 respectively to obtain the current actual displacement of the two probes. The grating reading head converts the displacement signal into an electrical signal and transmits it to the control unit 5. The displacement closed-loop control module built into the control unit 5 compares the displacement feedback signal with the target symmetrical measurement position calculated in step S2. If there is a deviation between the two, the control unit 5 sends a compensation control signal to the X-axis drive motor 323 to drive the two probes to fine-tune to the precise target position. After confirming that the position is correct, the control unit 5 records the displacement measurement value as the M value measurement data of the tooth groove position.

[0081] S6. Multi-point measurement of tooth surface: Control unit 5 controls the rotary indexing mechanism 49 or manually drives the internal gear 6 to be measured to rotate by a preset angle, and repeats steps S1 to S5 until the preset number of tooth groove positions are measured.

[0082] Specifically, for the equipment using the automatic workpiece carrying assembly of Embodiment 2, the control unit 5 sends a control signal to the rotary motor 491 of the rotary indexing mechanism 49. The rotary motor 491 drives the fixture disk 410 to rotate by a preset angle, which in turn drives the gear to rotate synchronously. For the equipment using the manual workpiece carrying assembly of Embodiment 1, the operator manually rotates the gear to rotate by a preset angle. After the rotation is completed, the control unit 5 repeats steps S1 to S5 to obtain the measurement data of the tooth groove at that angle position. The above process is repeated until all preset quantities of measurements are completed.

[0083] S7, M value calculation: The control unit 5 calculates and outputs the M value of the internal gear 6 to be measured based on the displacement measurement values ​​of each measurement.

[0084] Specifically, the control unit 5 adds the displacements of the two probes obtained from each measurement to obtain the span distance value at each tooth groove position. Since the definition of the M value is that when the two measuring balls (probes) are in contact with the tooth surfaces on both sides of the tooth groove at the same time, the distance between the centers of the two probe balls is equal to the sum of the absolute values ​​of the displacements of the two probes plus the sum of the radii of the two probes, the control unit 5 averages the measured values ​​at each tooth groove position according to the standard calculation formula of the M value to eliminate the random error of single-point measurement and calculate the final M value. The control unit 5 outputs the calculation results through the display screen or sends them to the host computer or MES system through the communication interface.

[0085] In the three embodiments described above, the control unit 5 is the core of the equipment's overall control. It is installed in an electrical box on one side of the base 1. The control unit 5 consists of a PLC controller, a touch screen, a data acquisition module, a signal amplification module, and a communication module. It is electrically connected to all drive components and detection elements of the equipment, enabling fully automatic linkage control and data processing. The control unit 5 has a communication interface for signal connection with an external robotic arm controller or automated production line control system, enabling automatic loading and unloading of the gear 6 to be measured and fully automatic online control of the measurement process. When the external robotic arm places the gear on the fixture plate 410, the control unit 5 automatically starts the measurement program. After the measurement is completed, it sends a completion signal to the robotic arm through the communication interface. The robotic arm then removes the measured gear and places the gear to be measured, achieving fully automatic cyclic measurement.

[0086] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. An instrument for measuring the M-value of internal gears, characterized in that, include: Base (1) The Z-axis lifting adjustment platform (2) is installed on the base (1) and is used to drive the measuring unit (3) to reciprocate in the vertical direction; The measuring unit (3), installed at the output end of the Z-axis lifting adjustment platform (2), includes: The X-axis bidirectional synchronous drive mechanism (32) has two output ends that move synchronously in opposite directions or in opposite directions along the X-axis direction; The middle slide plate (34) is floatingly set at the output end of the X-axis bidirectional synchronous drive mechanism (32); The force adjustment assembly (35) applies an adjustable constant elastic force to the middle slide plate (34) through an elastic element to provide the contact measurement force between the probe and the tooth surface; Two probe mounting rods (36) are respectively set on the middle slide plate (34), and a probe is set at one end of each probe mounting rod (36); A tooth profile feature recognition sensor is mounted on at least one probe mounting rod (36) for scanning the tooth profile and outputting tooth tip position signal and tooth root position signal; And a displacement detection component (38) for real-time detection of the actual displacement of the two probes and output of displacement feedback signal; The workpiece bearing assembly (4) is set on the machine base (1) and located below the measuring unit (3) for placing and positioning the internal gear (6) to be measured. The control unit (5) is mounted on the base (1) and is electrically connected to the Z-axis lifting adjustment platform (2), the X-axis bidirectional synchronous drive mechanism (32), the tooth profile feature recognition sensor and the displacement detection component (38).

2. The internal gear M-value measuring instrument according to claim 1, characterized in that: The force adjustment assembly (35) includes a spring adjustment plate (351) disposed on the measuring unit (3), a spring counter-pull plate (352) disposed on the middle slide plate (34), and a compression spring (353) and a compression spring adjustment screw (354) disposed between the spring adjustment plate (351) and the spring counter-pull plate (352). The spring counter-pull plate (352) moves synchronously with the middle slide plate (34), the compression spring adjusting screw (354) is threadedly connected to the spring counter-pull plate (352), one end of the compression spring (353) abuts against the compression spring adjusting screw (354), and the other end abuts against the spring adjusting plate (351). Rotating the spring adjusting screw (354) changes the pre-compression of the compression spring (353) to adjust the elastic force on the middle slide (34).

3. The internal gear M-value measuring instrument according to claim 1, characterized in that: At least one probe mounting rod (36) is a foldable probe mounting rod. The foldable probe mounting rod includes a probe mounting seat (362) set on the middle slide plate (34), a servo motor (363) set on the probe mounting seat (362), and a connecting plate (364) connecting the output shaft of the servo motor (363) and the probe. One end of the foldable probe mounting rod is rotatably mounted on the probe mounting seat (362) through a rotating shaft. The servo motor (636) drives the foldable probe mounting rod to rotate around the rotating shaft, so as to drive the probe to flip and switch between the horizontal measurement position and the vertical avoidance position.

4. The internal gear M-value measuring instrument according to claim 3, characterized in that: The tooth profile feature recognition sensor is installed at the end of the foldable probe mounting rod. The detection end of the tooth profile feature recognition sensor faces the tooth profile direction of the internal gear (6) to be measured and moves synchronously with the foldable probe mounting rod.

5. The internal gear M-value measuring instrument according to claim 1, characterized in that: The displacement detection component (38) is a dual-head grating ruler displacement detection component, including a grating ruler (381) set on the measuring unit (3) along the X-axis and linked with the two probes, and two grating reading heads set opposite to the grating ruler (381); the grating ruler (381) is set on the middle slide plate (34) and moves synchronously with the middle slide plate (34), and the two grating reading heads are set on the marble base plate (31) of the measuring unit (3); The output end of the X-axis bidirectional synchronous drive mechanism (32) is connected to the large slide plate (33). The large slide plate (33) has a travel limit switch (392) at both ends of its movement path. The large slide plate (33) has a limit sheet metal (3313) that cooperates with the travel limit switch (392). When the large slide plate (33) moves to the limit position, the limit sheet metal (3313) triggers the travel limit switch (392) to limit the extreme movement position of the two probes.

6. The internal gear M-value measuring instrument according to claim 1, characterized in that: The workpiece bearing assembly (4) is a manual workpiece bearing assembly. The manual workpiece bearing assembly includes a base plate (41), an intermediate plate (42) and a top plate (43) stacked in sequence. The base plate (41) is set on the machine base (1). A cross roller guide rail (44) is provided between the base plate (41) and the intermediate plate (42) to realize manual sliding adjustment. The top plate (43) is provided with mutually perpendicular stop adjustment seats. Each stop adjustment seat is connected with a stop adjustment strip, which is used to abut against the outer peripheral wall of the internal gear (6) to be tested from mutually perpendicular directions to complete manual centering and positioning.

7. The internal gear M-value measuring instrument according to claim 1, characterized in that: The workpiece bearing assembly (4) is an automatic workpiece bearing assembly, which includes: Support base (46) The Y-axis centering adjustment mechanism (8) is set on the bearing base (46) and is used to drive the internal gear (6) to be tested to move in the direction perpendicular to the X-axis in the horizontal plane to automatically correct the position of the internal gear (6) to be tested. A sliding connector (47) is installed at the output end of the Y-axis centering adjustment mechanism (8); A rotary indexing mechanism (49) is mounted on a sliding connector (47) and is used to drive the internal gear (6) under test to rotate and index around its vertical axis. A fixture disk (410) is installed at the output end of the rotary indexing mechanism (49), and the fixture disk (410) is provided with a positioning slot (4101) for placing the internal gear (6) to be tested.

8. The internal gear M-value measuring instrument according to claim 7, characterized in that: The Y-axis centering adjustment mechanism (8) includes a Y-axis guide rail (81) arranged on the bearing base (46) along the Y-axis direction, a Y-axis slide plate (82) slidably arranged on the Y-axis guide rail (81), and a Y-axis drive motor (83) arranged on the bearing base (46). The Y-axis drive motor (83) drives the Y-axis slide plate (82) to reciprocate along the Y-axis direction through a lead screw.

9. The internal gear M-value measuring instrument according to claim 1, characterized in that: During the process of the Z-axis lifting adjustment platform (2) driving the measuring unit (3) to move vertically to different tooth width sections, the X-axis bidirectional synchronous drive mechanism (32) simultaneously drives the middle slide plate (34) to reciprocate horizontally, so as to realize the continuous measurement of different tooth width sections of the internal gear. The control unit (5) calculates the center position of the tooth groove based on the tooth top position data and tooth bottom position data obtained by the tooth profile feature recognition sensor, and controls the X-axis bidirectional synchronous drive mechanism (32) to drive the slide plate (34) to move, so that the two probes are located at symmetrical measurement positions on both sides of the tooth groove center.

10. A method for measuring the M-value of an internal gear, using the internal gear M-value measuring instrument as described in any one of claims 1 to 9, characterized in that, Includes the following steps: S1, Tooth profile scanning: Control the X-axis bidirectional synchronous drive mechanism (32) to drive the probe to move towards the internal gear to be measured (6), and at the same time scan the tooth profile through the tooth profile feature recognition sensor to obtain at least one tooth tip position data and tooth root position data within a complete tooth pitch range; S2. Tooth groove center calculation: Based on the tooth tip position data and tooth root position data, calculate the offset of the tooth groove center relative to the initial position of the probe within the tooth pitch range, and determine the target symmetrical measurement position of the two probes accordingly. S3, probe centering feed: control the X-axis bidirectional synchronous drive mechanism (32) to drive the two probes to move synchronously from both sides to the target symmetrical measurement position; S4, Constant Force Contact: Control the two probes to continue to feed slowly towards each other at the first speed until the position detection switch of the force adjustment component (35) is triggered, confirming that the probes are in contact with the tooth surface with the set constant measuring force, and stop feeding; S5. Displacement measurement and feedback: The actual displacement of the two probes is read and recorded in real time through the displacement detection component (38); S6. Multi-point measurement of tooth surface: Control the rotary indexing mechanism (49) or manually drive the internal gear (6) to be measured to rotate by a preset angle, and repeat steps S1 to S5 until the preset number of tooth groove positions are measured. S7, M value calculation: Calculate and output the M value of the internal gear (6) to be measured based on the displacement measurement values ​​of each measurement.

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