A large deep hole part geometry error in-situ measurement system for straightening machine

Abstract

The application discloses a large-size deep-hole part geometric shape error in-situ measurement system for a straightening machine, relates to the in-situ measurement field of large-size deep-hole part geometric shape errors, and comprises a motion module, a displacement measurement module and a wall thickness measurement module, the motion module is fixed on a moving base of a straightening machine bed, the displacement measurement module comprises a bottom plate, a contact type displacement sensor and an absolute rotary encoder, the bottom plate is fixedly connected with a moving end of the motion module, a rotating shaft is arranged on the bottom plate, the contact type displacement sensor is fixed on the bottom plate, the wall thickness measurement module is provided with a swing plate, the swing plate is rotatably sleeved on the rotating shaft through a bearing, so that the wall thickness measurement module has a rotary degree of freedom relative to the displacement measurement module, a hollow shaft of the absolute rotary encoder is tightly connected with the tail end of the rotating shaft, and is used for recording the rotary angle of the wall thickness measurement module. The application can realize in-situ measurement of the roundness, axial straightness and geometric parameters of a large-size deep-hole part on the straightening machine.

Description

Technical Field

[0001] This invention belongs to the field of in-situ measurement of geometric shape errors of large deep hole parts, and specifically relates to an in-situ measurement system for geometric shape errors of large deep hole parts used in straightening machines. Background Technology

[0002] Large, variable cross-section deep-hole parts are key components in high-end equipment manufacturing, and their geometric errors, such as roundness and straightness, directly affect the overall performance and reliability of the machine. However, measuring the geometric errors of such parts efficiently and with high precision has always been a significant challenge. Traditional offline manual measurement requires removing the part from the straightening machine and transferring it to specialized equipment such as a coordinate measuring machine (CMM) for inspection. This process is not only time-consuming and labor-intensive, but also prone to introducing positioning errors during repeated disassembly and clamping of the workpiece. The measurement data cannot accurately reflect the actual state of the workpiece under straightening conditions, which is detrimental to closed-loop process control. Purely manual measurement relies on the operator's experience and skill, making it difficult to obtain a sufficient density of data points and comprehensively and accurately assess the shape error distribution of the entire deep-hole part. Existing in-situ measurement systems for deep-hole parts generally lack the ability to adapt to changes in workpiece radius. When the measured cross-sectional dimensions change, frequent manual intervention or replacement of measuring elements is required. At the same time, the system's measurement stroke is limited, making it difficult to completely cover the key areas of the variable cross-section deep-hole surface, resulting in insufficient cross-sectional contour data and axial measurement points, which restricts the complete extraction of geometric errors.

[0003] Therefore, how to provide an in-situ measurement system for the geometric shape error of large deep hole parts that can be integrated with a straightening machine, has the ability to adapt to the workpiece radius, and can achieve high-precision fully automatic measurement has become a problem that needs to be considered by those skilled in the art. Summary of the Invention

[0004] The purpose of this invention is to overcome the above-mentioned shortcomings of the prior art and provide an in-situ measurement system for geometric shape errors of large deep hole parts for straightening machines. This invention can perform in-situ measurements of roundness, axial straightness and geometric parameters of large deep hole parts on straightening machines. It can adaptively adjust the measurement posture according to the workpiece size to realize in-situ measurement of large variable cross-section deep hole parts. It has the advantages of high measurement accuracy and high efficiency, and is convenient to use and maintain.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A system for in-situ measurement of geometric shape errors of large deep-hole parts for a straightening machine includes a motion module, a displacement measurement module, and a wall thickness measurement module. The motion module is fixed on the movable base of the straightening machine. The displacement measurement module includes a base plate, a contact displacement sensor, and an absolute rotary encoder. The base plate is fixedly connected to the movable end of the motion module, and a rotating shaft is fastened to the base plate. The contact displacement sensor is fixed to the base plate by a pad and is used to measure the outer diameter contour data of the workpiece. The wall thickness measurement module is equipped with a swing plate, which is rotatably mounted on the rotating shaft by a bearing, thereby giving the wall thickness measurement module rotational freedom relative to the displacement measurement module. The hollow shaft of the absolute rotary encoder is fastened to the end of the rotating shaft and is used to record the rotation angle of the wall thickness measurement module.

[0006] Furthermore, the motion module includes a z-axis column, a rotary motor, a turntable, a y-axis column, a y-axis linear module, a connecting plate, and the z-axis linear module. The z-axis column is fixedly connected to the movable base. The rotary motor is mounted on the top of the z-axis column. The turntable is connected to the output end of the rotary motor. The y-axis column is mounted on the turntable. The y-axis linear module is mounted on the y-axis column. The connecting plate is mounted on the slide of the y-axis linear module. The z-axis linear module is mounted on the connecting plate. The base plate is fastened to the slide of the z-axis linear module.

[0007] Furthermore, the wall thickness measurement module also includes a guide rail, a slider, a stop block, a compression spring, an ultrasonic probe, a bracket, and rollers. The guide rail is fastened to the front of the swing plate, and the slider is slidably limited on the guide rail. The stop block is fastened to the front of the swing plate and located at the upper end of the guide rail. The compression spring is disposed between the stop block and the slider, with one end fixed in a reserved hole in the stop block and the other end fixed to the top of the slider to provide a preload force that keeps the slider pressed against the workpiece surface. The ultrasonic probe is fastened to the slider via an ultrasonic probe clamp and moves with the slider to measure the workpiece wall thickness. The bracket is fastened to the bottom of the slider, and the rollers are rotatably mounted at a reserved hole at the bottom of the bracket. The rollers are used to contact the workpiece surface to guide the ultrasonic probe to move adaptively with the undulations of the workpiece surface.

[0008] Furthermore, the displacement measurement module also includes a bearing mounting structure and a locking nut. The bearing mounting structure includes a first end cap and a second end cap disposed on the swing plate. The outer ring of the bearing is fastened to the first end cap and the second end cap by bolts. The inner ring of the bearing is interference-fitted with the rotating shaft to rotatably connect the swing plate to the rotating shaft. The locking nut is fastened to the threaded section of the rotating shaft to axially lock the bearing.

[0009] Furthermore, the displacement measurement module also includes an adaptive tensioning component, which includes a stop pin, a first stud, a second stud, and a tension spring. The stop pin is fastened to the base plate, the first stud is fastened to the base plate, and the second stud is fastened to the rear end of the swing plate of the wall thickness measurement module. The two ends of the tension spring are hooked onto the first stud and the second stud, respectively. By adjusting the rotation angle of the swing plate, the distance between the two studs is changed, causing the tension spring to generate a preload, thereby realizing the adaptive adjustment of the contact force applied by the wall thickness measurement module to the workpiece surface.

[0010] Furthermore, it also includes a mobile positioning mechanism, which includes a gear and rack mechanism and a linear guide rail on the straightening machine tool body. The z-axis column is fastened to the base of the moving part of the gear and rack mechanism by bolts, so that the entire measurement system can move and position within the axial space of the machine tool.

[0011] Furthermore, the pad has a through hole, through which the contact displacement sensor passes and is fastened. Its probe is located on the outside of the base plate and is used to directly contact and measure the runout of the outer circle contour of the workpiece.

[0012] Furthermore, the rotary motor is a servo motor, used to drive the rotation of the turntable and the structure connected thereto, so as to adjust the measurement posture of the wall thickness measurement module and the displacement measurement module relative to the workpiece.

[0013] The beneficial effects of this invention are as follows: 1. The in-situ measurement system for geometric shape error of large deep hole parts integrated with a straightening machine disclosed in this invention can be used without moving the workpiece compared with traditional offline inspection methods. This eliminates the error caused by secondary clamping or position change of the workpiece, shortens the inspection time, and ensures the consistency between the measurement datum and the machining datum. It has the advantages of high measurement accuracy and high efficiency.

[0014] 2. The in-situ measurement system for geometric shape error of large deep hole parts integrated with the straightening machine disclosed in this invention can completely cover the workpiece surface by adjusting the position of the rotating mechanism and the Z-axis module, in conjunction with the rotation of the machine tool roller, thereby realizing automated measurement.

[0015] 3. The in-situ measurement system for geometric shape errors of large deep-hole parts integrated with a straightening machine disclosed in this invention employs a wall thickness adaptive measurement device based on pulley blocks, tension springs, and compression springs. This allows the ultrasonic probe to automatically adjust its deflection angle during measurement, and its measurement axis, under the constraint of spring restoring force and mechanism, passes through the center of the measured cross-section. This adaptive function ensures the stability of the measurement reference and the consistency of data acquisition.

[0016] 4. The in-situ measurement system for geometric shape errors of large deep-hole parts integrated with a straightening machine disclosed in this invention innovatively integrates a contact displacement sensor, an ultrasonic probe, and an absolute rotary encoder. The contact displacement sensor is responsible for measuring the external contour information of the workpiece, the ultrasonic probe is used to measure the wall thickness information of the deep-hole part, and the absolute rotary encoder records the axial angle information of the wall thickness measuring device. By processing multi-source data through physical quantity geometric constraints, the inner and outer contour data of the measured circular cross-section and the centers of the inner and outer circles are calculated. A three-dimensional model of the target measured workpiece is fitted, realizing comprehensive and precise detection of the roundness, axial straightness, and inner and outer contours of the deep-hole part, with highly integrated functions.

[0017] 5. The in-situ measurement system for geometric shape errors of large deep hole parts integrated with a straightening machine disclosed in this invention, based on the system's geometric parameters and real-time sensor data, can fit contour data in real time during the measurement process, reconstruct the inner and outer circular contours of each measurement section, and finally fit a complete three-dimensional model of the workpiece, realizing in-situ and rapid evaluation of key geometric shape errors such as roundness and axial straightness. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the on-campus direct-machine integration operation of the present invention; Figure 2 This is a schematic diagram of the main structure of the present invention; Figure 3 This is an exploded view of the entire invention; Figure 4 This is an exploded view of the displacement measurement module of the present invention; Figure 5 This is an exploded view of the wall thickness measurement module of the present invention; Figure 6 This is a schematic diagram showing the spatial geometric relationship of each sensor during measurement in this invention; Figure 7 This is a schematic diagram illustrating the spatial geometric relationships of various physical quantities during the measurement process of this invention.

[0019] In the picture: 1-Z-axis column, 2-rotary motor, 3-turntable, 4-Y-axis column, 5-Y-axis linear module, 6-connecting plate, 7-Z-axis linear module, 8-displacement measurement module, 9-wall thickness measurement module, 10-gear and rack mechanism, 11-linear guide rail; 801-Base plate, 802-Rotating shaft, 803-Sealing ring, 804-End cap No. 1, 805-Bearing, 806-Locking nut, 807-End cap No. 2, 808-Absolute rotary encoder, 809-Stop pin, 810-Stud No. 1, 811-Tension spring, 812-Stud No. 2, 813-Padded block, 814-Contact displacement sensor; 901-Swing plate, 902-Baffle, 903-Guide rail, 904-Stop block, 905-Compression spring, 906-Slider, 907-Limit block, 908-Ultrasonic probe, 909-Ultrasonic probe clamp, 910-Bracket, 911-Roller, 912-Nut. Detailed Implementation

[0020] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0021] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "horizontal," "inner," "outer," and "one side," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. The terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, unless otherwise explicitly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0022] Example 1

[0023] like Figure 1-7 As shown, this embodiment discloses an in-situ measurement system for geometric shape errors of large deep-hole parts used in a straightening machine, including a z-axis column 1, a rotary motor 2, a turntable 3, a y-axis column 4, a y-axis linear module 5, a connecting plate 6, a z-axis linear module 7, a displacement measurement module 8, and a wall thickness measurement module 9. The z-axis column 1 is used to be securely connected to the movable base on the straightening machine tool. The rotary motor 2 is mounted on the top of the z-axis column 1. The turntable 3 is connected to the output end of the rotary motor 2. The y-axis column 4 is mounted on the turntable 3. The y-axis linear module 5 is mounted on the y-axis column 1. The connecting plate 6 is mounted on the slide of the y-axis linear module 5. The z-axis linear module 7 is mounted on the connecting plate 6. The displacement measurement module 8 and the wall thickness measurement module 9 are mounted on the slide of the z-axis linear module 7.

[0024] As a preferred embodiment of the present invention, it also includes a moving positioning mechanism, which includes a gear and rack mechanism 10 and a linear guide rail 11 on the straightening machine tool body. The z-axis column 1 is fastened to the base of the moving part of the gear and rack mechanism 10 by bolts, so that the entire measurement system can be moved and positioned in the axial space of the machine tool.

[0025] See appendix Figure 4 The displacement measurement module 8 includes a base plate 801, a rotating shaft 802, a sealing ring 803, a first end cover 804, a bearing 805, a locking nut 806, a second end cover 807, an absolute rotary encoder 808, a stop pin 809, a first stud 810, a tension spring 811, a second stud 812, a pad 813, and a contact displacement sensor 814. The base plate 801 is fastened to the slide of the z-axis linear module 7 by bolts. The rotating shaft 802 is fastened to the base plate 801 by bolts. The sealing ring 803 is fitted on the outside of the rotating shaft 802. The first end cover 804 is fastened to the swing plate 901 in the wall thickness measurement module 9 by bolts to ensure that there is no relative movement between them. The inner ring of the bearing 805 is interference-fitted with the rotating shaft 802, and the outer ring of the bearing is fastened to the inner ring of the first end cover 804 by bolts, so that the wall thickness measurement module 9 has a degree of rotational freedom. The locking nut 806 is fastened to the rotating shaft 802. The threaded section 02 enables axial locking of bearing 805; end cap 807 is fastened to bearing 805 by bolts; absolute rotary encoder 808 is fastened to end cap 807 by bolts, and the encoder hollow shaft is fastened to the end of rotating shaft 802; stop pin 809 is fastened to base plate 801 by bolts; stud 810 is fastened to base plate 801; stud 812 is fastened to the rear end of swing plate 901 in wall thickness measurement module 9; tension spring 811 has hooks at both ends, one hook is connected to stud 810, and the other hook is connected to stud 812. By adjusting the rotation angle of swing plate 901, the relative distance between stud 810 and stud 812 is changed to ensure that the tension spring has a certain preload; pad 813 is fastened to base plate 801 by bolts; contact displacement sensor 814 is fastened to pad 813 by bolts.

[0026] See appendix Figure 5The wall thickness measurement module 9 includes a swing plate 901, a baffle 902, a guide rail 903, a stop block 904, a compression spring 905, a slider 906, a limit block 907, an ultrasonic probe 908, an ultrasonic probe clamp 909, a bracket 910, a roller 911, and a nut 912. The baffle 902 is bolted to the side of the swing plate 901. The guide rail 903 is bolted to the front of the swing plate 901. The stop block 904 is bolted to the front of the swing plate 901. The slider 906 is placed in conjunction with the guide rail 903, giving the slider a degree of freedom of movement in the guide rail direction. One end of the compression spring 905 is placed in a pre-drilled hole at the bottom of the stop block 904, allowing for... The spring is fixed with bolts, and the other end of the spring is fixed to the top of the slider 906 with bolts. By compressing the distance between the slider and the stop, the spring is ensured to have a certain preload. The limit block 907 is fastened to the slider 906 with bolts. The ultrasonic probe 908 is installed in the ultrasonic probe clamp 909. The clamping force of the clamp is adjusted by adjusting the bolts on the ultrasonic probe clamp 909. The ultrasonic probe clamp 909 is fastened to the slider 906 with bolts. The bracket 910 is fastened to the bottom of the slider 906 with bolts. The roller 911 passes through the reserved hole at the bottom of the bracket 910 and is fastened to the nut 912, so that the roller can roll on the clamp.

[0027] Specifically, after the initial setup of the system is completed, the angle of the absolute rotary encoder 808 should be calibrated so that the 0° scale of the absolute rotary encoder coincides with the central axis of the wall thickness measurement module 9, to ensure the reliability of the angle measurement by the absolute rotary encoder 808. The distance from the center of the rotating shaft 802 to the measurement axis of the contact displacement sensor 814 should be calibrated as a reference for subsequent data processing.

[0028] The specific usage process of this invention is as follows: As a preparatory step before measurement, to ensure the system is in the best working environment, standard cylindrical parts need to be clamped on the straightening machine rollers before measurement. The moving measurement platform is then moved to the zero position, and the z-axis perpendicularity, y-axis horizontality, rotation axis position, and displacement probe position of the measurement system are calibrated and adjusted. At the same time, to ensure that the pulleys in the wall thickness measurement module are always in close contact with the workpiece surface, the lengths of the compression spring, tension spring, and stop pin need to be adjusted to achieve the desired posture and ensure that the springs have sufficient tension and pressure.

[0029] See appendix Figure 2 The z-axis column 1 of the in-situ measurement system for geometric shape errors of large deep-hole parts is fastened to the base in the gear and rack module of the straightening machine tool by bolts. Two guide rail sliders are fastened to the bottom of the base, allowing it to slide along the guide rails. A servo motor drives the gears in the gear and rack mechanism to rotate, and through the meshing transmission between the gears and racks, the measurement system achieves axial spatial displacement along the guide rails.

[0030] The coordinate system used in this invention is described in the appendix. Figure 1 The deep-hole part is placed on the movable roller of the clamping and positioning device. The rotation of the roller drives the deep-hole part to rotate. The gear rack and linear guide module on the straightening machine body realizes the positioning and movement of the in-situ measurement system in the X-axis direction of the machine tool space. The Y-axis linear module 5 is responsible for the positioning and movement of the measurement module in the Y-axis direction of the machine tool space, and the Z-axis linear module 7 is responsible for the positioning and movement of the measurement module in the Z-axis direction of the machine tool space. The rotary motor 2 and the turntable 3 are responsible for adjusting the rotational posture of the measurement module. The X, Y, Z-axis and rotational four-degree-of-freedom posture adjustment in-situ measurement system measures the geometric shape error in the vertical direction of the deep-hole part, and avoids spatial interference problems in the loading and unloading scenarios of deep-hole parts.

[0031] After measurement begins, the x and y axis linear modules move to the predetermined positions on the measurement interface. The z-axis linear module 7 controls the measurement module to move downwards. The left roller in the roller assembly 911 contacts the workpiece surface first. As the z-axis continues to move downwards, due to the physical constraints of the mechanism, the wall thickness measurement module 9 is subjected to a clockwise torque applied by the workpiece surface, stretching the tension spring 811 and increasing the tension. Simultaneously, as the z-axis linear module continues to move downwards, the spatial position of the wall thickness measurement module 9 is compressed, compressing the compression spring 905 and increasing the spring force. This ensures that the roller assembly 911 remains in close contact with the workpiece surface, thereby maintaining a constant distance between the ultrasonic probe 908 and the workpiece surface, achieving adaptive posture adjustment. The z-axis linear module moves downwards until the contact displacement sensor 814 has a certain downward pressure. The wall thickness measurement module 9 also completes its adaptive posture adjustment due to the aforementioned process. Both the ultrasonic probe 908 and the contact displacement sensor 814 enter a suitable working state and can perform data sampling.

[0032] When measuring the current cross-section, the spatial geometric relationships of each sensor are shown in the appendix. Figure 6 θ1 is the deflection angle of the axis in the wall thickness measurement module 9 recorded by the absolute rotary encoder 808. This refers to the phase difference between the measurement data from the ultrasonic probe 908 and the measurement data from the contact displacement sensor 814. L1 is the distance from the axis of the rotating shaft 802 obtained through calibration to the measurement axis of the contact displacement sensor 814. L2 is the horizontal distance from the side position of the contact displacement sensor 814 to the axis of the rotating shaft 802 in the initial state, which can be obtained through initial state calibration. This is the change in outer circular runout measured by the contact displacement sensor 814. At this time, the phase difference is... Phase alignment is performed on the two types of measurement data, and the outer radius of the current cross section is... It can be obtained through equation (1): (1) When measuring cross-sectional data, the machine tool spindle rotates, and the machine tool's built-in rotary encoder records the spindle rotation angle. The spindle rotates an angle relative to its initial position. There is a phase difference between the outer diameter runout measurement data of the contact displacement sensor 814 and the wall thickness measurement data of the ultrasonic probe 908. The value of the phase difference is obtained by the absolute rotary encoder 808. The measurement data obtained by the above three types of sensors, along with the machine tool spindle rotation angle, can be used to fit the inner and outer contours of the currently measured part in real time. The relationship between the various geometric quantities is shown in the appendix. Figure 7 inner circle radius It can be obtained through equation (2): (2) Repeatedly measure all circular cross sections, and fit the three-dimensional model of the workpiece to the host computer. The three-dimensional model contains information such as the roundness, diameter, wall thickness and straightness of the axis of the deep hole part, and finally realizes the in-situ measurement of the deep hole part.

[0033] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A system for in-situ measurement of geometric shape error of large deep-hole parts used in a straightening machine, characterized in that, The system includes a motion module, a displacement measurement module, and a wall thickness measurement module. The motion module is fixed on the movable base of the straightening machine tool. The displacement measurement module includes a base plate, a contact displacement sensor, and an absolute rotary encoder. The base plate is fixedly connected to the movable end of the motion module, and a rotating shaft is fastened to the base plate. The contact displacement sensor is fixed to the base plate by a pad and is used to measure the outer diameter contour data of the workpiece. The wall thickness measurement module is equipped with a swing plate, which is rotatably mounted on the rotating shaft by a bearing, thereby giving the wall thickness measurement module a rotational degree of freedom relative to the displacement measurement module. The hollow shaft of the absolute rotary encoder is fastened to the end of the rotating shaft and is used to record the rotation angle of the wall thickness measurement module.

2. The in-situ measurement system for geometric shape error of large deep-hole parts for a straightening machine according to claim 1, characterized in that, The motion module includes a Z-axis column, a rotary motor, a turntable, a Y-axis column, a Y-axis linear module, a connecting plate, and the Z-axis linear module. The Z-axis column is fixedly connected to the movable base. The rotary motor is mounted on the top of the Z-axis column. The turntable is connected to the output end of the rotary motor. The Y-axis column is mounted on the turntable. The Y-axis linear module is mounted on the Y-axis column. The connecting plate is mounted on the slide of the Y-axis linear module. The Z-axis linear module is mounted on the connecting plate. The base plate is fastened to the slide of the Z-axis linear module.

3. The in-situ measurement system for geometric shape error of large deep-hole parts for a straightening machine according to claim 1, characterized in that, The wall thickness measurement module also includes a guide rail, a slider, a stop block, a compression spring, an ultrasonic probe, a bracket, and rollers. The guide rail is fastened to the front of the swing plate, and the slider is slidably limited on the guide rail. The stop block is fastened to the front of the swing plate and located at the upper end of the guide rail. The compression spring is disposed between the stop block and the slider, with one end fixed in a reserved hole in the stop block and the other end fixed to the top of the slider to provide a preload force that keeps the slider pressed against the workpiece surface. The ultrasonic probe is fastened to the slider via an ultrasonic probe clamp and moves with the slider to measure the workpiece wall thickness. The bracket is fastened to the bottom of the slider, and the rollers are rotatably mounted at a reserved hole at the bottom of the bracket. The rollers are used to contact the workpiece surface to guide the ultrasonic probe to move adaptively with the undulations of the workpiece surface.

4. The in-situ measurement system for geometric shape error of large deep-hole parts for a straightening machine according to claim 1, characterized in that, The displacement measurement module also includes a bearing mounting structure and a locking nut. The bearing mounting structure includes a first end cap and a second end cap disposed on the swing plate. The outer ring of the bearing is fastened to the first end cap and the second end cap by bolts. The inner ring of the bearing is interference-fitted with the rotating shaft to rotatably connect the swing plate to the rotating shaft. The locking nut is fastened to the threaded section of the rotating shaft to axially lock the bearing.

5. The in-situ measurement system for geometric shape error of large deep-hole parts for a straightening machine according to claim 1, characterized in that, The displacement measurement module further includes an adaptive tensioning component, which includes a stop pin, a first stud, a second stud, and a tension spring. The stop pin is fastened to the base plate, the first stud is fastened to the base plate, and the second stud is fastened to the rear end of the swing plate of the wall thickness measurement module. The two ends of the tension spring are hooked onto the first stud and the second stud, respectively. By adjusting the rotation angle of the swing plate, the distance between the two studs is changed, causing the tension spring to generate a preload, thereby realizing the adaptive adjustment of the contact force applied by the wall thickness measurement module to the workpiece surface.

6. The in-situ measurement system for geometric shape error of large deep-hole parts for a straightening machine according to claim 2, characterized in that, It also includes a moving positioning mechanism, which includes a gear and rack mechanism and a linear guide rail on the straightening machine tool body. The z-axis column is fastened to the base of the moving part of the gear and rack mechanism by bolts, so that the entire measurement system can move and position within the axial space of the machine tool.

7. The in-situ measurement system for geometric shape error of large deep-hole parts for a straightening machine according to claim 1, characterized in that, The pad has a through hole, through which the contact displacement sensor passes and is fastened. Its probe is located on the outside of the base plate and is used to directly contact and measure the runout of the outer circle contour of the workpiece.

8. The in-situ measurement system for geometric shape error of large deep-hole parts for a straightening machine according to claim 2, characterized in that, The rotary motor is a servo motor, used to drive the rotation of the turntable and the structure connected to it, so as to adjust the measurement posture of the wall thickness measurement module and the displacement measurement module relative to the workpiece.

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