Taper inspection fixture for large conical workpieces
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-10
- Publication Date
- 2026-08-14
AI Technical Summary
[0003]部分大型锥形工件可能长达数米至数十米，由于尺寸与重量限制，传统三坐标测量机（CMM）无法容纳，且重型工件吊装困难，便携式光学检测设备难以实现稳定精准定位
[0014]由于本实用新型大型锥形工件的锥度检测工装采用了上述技术方案，即本工装的端面固定单元包括表面光滑的矩形板和接长杆，矩形板设于接长杆顶端，接长杆底端设有安装孔；轴向延伸单元包括加长杆，加长杆一端连接端面固定单元接长杆的安装孔、另一端连接采集单元；采集单元的连接杆一端与轴向延伸单元的加长杆螺纹连接、另一端垂直轴向设有通孔，测量杆穿入连接杆的通孔，固定夹板夹持测量杆固定与连接杆的相对位置，测量底座设于测量杆一端，测量靶球设于测量座，测量杆另一端为锥体，锥体顶端与检测对象的锥体表面点接触；长度校准单元的精密平板居中设有锥孔，并与测量杆的锥体匹配。利用采集单元采集大型锥形工件锥体端面以及锥体表面的特征点，经长度校准单元获得锥体表面截面的直径，通过公式计算得到大型锥形工件的锥度值。本工装及方法克服传统锥度检测的缺陷，应用激光跟踪仪等精密光学检测设备实现大型锥形工件的高精度锥度测量，提高检测精度及效率，确保大型锥形工件的形位参数。
Smart Images
Figure CN224635991U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of detection technology, and in particular to a tooling and method for detecting the taper of a large conical workpiece. Background Technology
[0002] Taper inspection is a key quality control step in mechanical manufacturing. Taper inspection of large tapered workpieces (such as large bearing housing tapered sleeves, wind turbine main shafts, large bushings, ship propellers, etc.) faces many challenges due to their large size, heavy weight, and interference from environmental factors. The inspection difficulty is significantly higher than other parameters. Taper inspection is the main parameter that restricts the manufacturing and maintenance accuracy of tapered parts.
[0003] Some large conical workpieces may be several meters to tens of meters long. Due to size and weight limitations, traditional coordinate measuring machines (CMMs) cannot accommodate them, and heavy workpieces are difficult to lift. Portable optical inspection equipment is also unable to achieve stable and accurate positioning.
[0004] The taper tolerance of large conical workpieces is usually required to be ≤0.02mm / m, with high requirements for accuracy and repeatability. However, traditional testing equipment has significant cumulative errors under large dimensions, and environmental vibration and temperature deformation (such as ±1℃ can cause an error of 0.01mm / m) affect the measurement stability.
[0005] Traditional inspection methods have many limitations when dealing with large sizes, high precision, and complex working conditions. Therefore, they cannot meet the accuracy and on-site environment requirements for taper inspection of large conical workpieces. When conventional portable laser trackers are used to inspect the taper of large conical workpieces, due to software modeling and data processing defects, as well as the accuracy of non-conventional cylindrical target ball inspection, it is usually difficult to directly achieve high-precision taper inspection of large conical workpieces. Taper inspection of large conical workpieces has always been a difficult problem in the field of high-precision inspection using laser trackers as the main optical equipment. Summary of the Invention
[0006] The technical problem to be solved by this utility model is to provide a taper detection fixture for large conical workpieces. This fixture overcomes the defects of traditional taper detection and uses precision optical detection equipment such as laser trackers to achieve high-precision taper measurement of large conical workpieces, thereby improving detection accuracy and efficiency and ensuring the form and position parameters of large conical workpieces.
[0007] To solve the above-mentioned technical problems, the taper detection fixture for large conical workpieces of this utility model includes an end face fixing unit, an axial extension unit, a data acquisition unit, and a length calibration unit.
[0008] The end face fixing unit includes a smooth rectangular plate and an extension rod. The rectangular plate is located at the top of the extension rod, and the bottom of the extension rod is provided with a mounting hole.
[0009] The axial extension unit includes an extension rod, one end of which is connected to the mounting hole of the extension rod of the end face fixing unit, and the other end is connected to the acquisition unit;
[0010] The acquisition unit includes a connecting rod, a measuring rod, a measuring base, a measuring target ball, and a fixing clamp. One end of the connecting rod is threaded to the extension rod of the axial extension unit, and the other end has a through hole perpendicular to the axial direction. The measuring rod passes through the through hole of the connecting rod. The fixing clamp holds the measuring rod and fixes it in a fixed position relative to the connecting rod. The measuring base is located at one end of the measuring rod, and the measuring target ball is located at the measuring base. The other end of the measuring rod is a cone, and the top of the cone makes point contact with the cone surface of the large conical workpiece.
[0011] The length calibration unit is a precision plate with a conical hole in the center, which matches the cone of the measuring rod of the acquisition unit.
[0012] Furthermore, the extension rod of the end face fixing unit, the extension rod of the axial extension unit, and the measuring rod of the acquisition unit are each composed of multiple rod segments connected by threads.
[0013] Furthermore, the surface flatness of the precision plate of the length calibration unit is 0.01 mm, the depth of the conical hole is calibrated in the laboratory using a benchtop coordinate measuring machine, and the distance deviation caused by the cone of the measuring rod being placed in the conical hole and the cone of the measuring rod being placed on the surface of the precision plate is detected by a laser tracker.
[0014] Because this utility model's large conical workpiece taper detection fixture adopts the above-mentioned technical solution, namely, the end face fixing unit of this fixture includes a smooth rectangular plate and an extension rod, with the rectangular plate located at the top of the extension rod and a mounting hole at the bottom of the extension rod; the axial extension unit includes an extension rod, with one end connected to the mounting hole of the extension rod in the end face fixing unit and the other end connected to the acquisition unit; one end of the connecting rod of the acquisition unit is threadedly connected to the extension rod of the axial extension unit, and the other end has a through hole perpendicular to the axial direction, through which the measuring rod passes. A fixing clamp holds the measuring rod and fixes its relative position to the connecting rod; a measuring base is located at one end of the measuring rod; a measuring target ball is located at the measuring base; the other end of the measuring rod is a cone, with the top of the cone making point contact with the cone surface of the object being tested; the precision plate of the length calibration unit has a conical hole in the center, which matches the cone of the measuring rod. The acquisition unit collects feature points on the cone end face and the cone surface of the large conical workpiece, and the diameter of the cone surface section is obtained by the length calibration unit. The taper value of the large conical workpiece is then calculated using a formula. This tooling and method overcomes the shortcomings of traditional taper detection, and uses precision optical inspection equipment such as laser trackers to achieve high-precision taper measurement of large tapered workpieces, thereby improving detection accuracy and efficiency and ensuring the form and position parameters of large tapered workpieces. Attached Figure Description
[0015] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments:
[0016] Figure 1 This is a schematic diagram of the taper detection fixture for large conical workpieces according to this utility model. Detailed Implementation
[0017] Implementation, for example Figure 1 As shown, the taper detection fixture for large conical workpieces of this utility model includes an end face fixing unit, an axial extension unit, a data acquisition unit, and a length calibration unit.
[0018] The end face fixing unit includes a smooth rectangular plate 11 and an extension rod 12. The rectangular plate 11 is located at the top of the extension rod 12, and the extension rod 12 has a mounting hole at its bottom.
[0019] The axial extension unit includes an extension rod 21, one end of which is connected to the mounting hole of the extension rod 12 of the end face fixing unit, and the other end is connected to the acquisition unit.
[0020] The acquisition unit includes a connecting rod 31, a measuring rod 32, a measuring base 33, a measuring target ball 34, and a fixing clamp 35. One end of the connecting rod 31 is threadedly connected to the extension rod 21 of the axial extension unit, and the other end is provided with a through hole perpendicular to the axial direction. The measuring rod 32 passes through the through hole of the connecting rod 31. The fixing clamp 35 clamps the measuring rod 32 and fixes its relative position to the connecting rod 31. The measuring base 33 is located at one end of the measuring rod 32, and the measuring target ball 34 is located at the measuring base 33. The other end of the measuring rod 32 is a cone 36, and the top of the cone 36 makes point contact with the cone surface 51 of the large conical workpiece 5.
[0021] The length calibration unit is a precision plate 4, and a conical hole 41 is provided in the center. The conical hole 41 matches the cone 36 of the measuring rod 32 of the acquisition unit.
[0022] Preferably, the extension rod 12 of the end face fixing unit, the extension rod 21 of the axial extension unit, and the measuring rod 32 of the acquisition unit are each composed of multiple rod segments connected by threads.
[0023] Preferably, the surface flatness of the precision plate 4 of the length calibration unit is 0.01 mm, the depth of the conical hole 41 is calibrated in the laboratory using a benchtop coordinate measuring machine, and the distance deviation caused by the cone 36 of the measuring rod 32 being placed in the conical hole 41 and the cone 36 of the measuring rod 32 being placed on the surface of the precision plate 4 is detected by a laser tracker.
[0024] The function of the end face fixing unit is to ensure that the taper surface feature points can be collected on the tapered surface of the cone at a fixed length interval from the end face of the object being inspected. Due to the size difference of the object being inspected, the end face fixing unit is made into a combined connection mode. Each section of the rod is machined with internal thread holes and external threads, which can be freely combined according to the size of the object being inspected.
[0025] Due to the size differences of the objects being inspected, the extended rods of the axial extension unit are made in a combined connection mode. Similarly, each rod segment is machined with internal and external threads, which can be freely combined according to the size of the objects being inspected.
[0026] During on-site testing, the acquisition unit determines the target object and location. After the end-face fixing unit, axial extension unit, and acquisition unit are fixedly connected, and the measuring rod passes through the connecting rod and contacts the characteristic point on the conical surface of the target object, a fixing clamp is installed above and below the connection point between the measuring rod and the connecting rod through hole. This locks the connection point, ensuring the measuring rod will not move along the through hole in the vertical direction of the connecting rod. The fixing clamp contains a spring clip, which can be manually opened to clamp the measuring rod and then closed. This clamp is used to fix the measuring rod on both sides after it passes through the connecting rod through hole. The acquisition unit collects characteristic points of a fixed diameter on the conical surface of the target object at a fixed interval of a fixed length from the end face of the target object through the conical tip at one end of the measuring rod. The conical hole in the length calibration unit ensures that the conical tip of the measuring rod can make perpendicular contact with the length calibration unit, eliminating the need for leveling during on-site calibration and measurement.
[0027] A method for taper detection of a large conical workpiece based on the above-mentioned inspection fixture includes the following steps:
[0028] Step 1: Based on the dimensions of the large conical workpiece, select the appropriate extension rod length of the end face fixing unit, and ensure that the smooth surface of the rectangular plate effectively contacts the conical end face of the large conical workpiece, and rotate it 360 degrees around the conical end face.
[0029] Step 2: Based on the dimensions of the large conical workpiece, select the appropriate length of the extension rod for the axial extension unit, and connect the extension rod to the mounting hole of the extension rod. Through the rectangular plate, make effective contact with the conical end face of the large conical workpiece, and drive the extension rod to rotate 360 degrees along the conical end face of the large conical workpiece.
[0030] Step 3: Determine the length of the measuring rod of the acquisition unit based on the diameter of the large conical workpiece and the length of the axial extension unit. The length of the measuring rod should be such that the top of the cone of the measuring rod makes point contact with the surface of the object being inspected. At the same time, after being connected to the end face fixing unit and the axial extension unit, the length of the measuring rod should be able to ensure that it rotates 360 degrees synchronously with the end face fixing unit along the cone end face of the large conical workpiece.
[0031] Step 4: The measuring rod of the acquisition unit is driven to rotate along the first section of the cone surface of the large conical workpiece by the end face fixing unit and the axial extension unit, and the cone of the measuring rod is used to acquire the feature points of the cone surface of the large conical workpiece.
[0032] Step 5: Power on the laser tracker, use the measuring target ball to collect the feature points on the cone end face of the large conical workpiece, and fit them as a reference plane and reference coordinate system;
[0033] Step 6: The laser tracker collects feature points on the surface of the large conical workpiece by measuring the cone tip of the measuring rod through the measuring target ball, and meets the requirements of roundness fitting. All feature points are fitted to the circumference, and the diameter S1 of the rotating measuring target ball and the distance L1 between the first cross section and the end face are recorded.
[0034] Step 7: Remove the acquisition unit from the axial extension unit, place the cone of the measuring rod into the cone hole of the length calibration unit, place the measuring target ball on the measuring base, and acquire the feature points of the measuring target ball;
[0035] Step 8: Use the measuring target ball to collect surface feature points of the length calibration unit, fit a plane in the laser tracker to compensate for the radius of the measuring target ball, and determine the calibration reference plane;
[0036] Step 9: Inside the laser tracker, by calculating the distance from the feature point of the target ball on the measuring base to the surface of the length calibration unit, determine the distance T1 from the measuring point on the measuring base to the calibration reference surface. By using the cone hole depth S0 of the length calibration unit that has been calibrated in the laboratory, determine the distance from the measuring point on the measuring base to the cone hole of the length calibration unit, that is, the distance from the measuring point on the measuring base to the top of the cone of the measuring rod.
[0037] Step 10: Since the top of the measuring rod is in point contact with the cone surface of the large conical workpiece, the distance from the measuring point on the measuring base to the cone surface of the large conical workpiece is T1+S0. Therefore, the diameter of the first section of the cone surface of the large conical workpiece is D1=S1-T1-S0.
[0038] Step 11: Repeat steps 4 to 10 to determine the diameter D2 of the second section of the large conical workpiece and the distance L2 between the section and the end face;
[0039] Step 12: According to the taper calculation formula, taper = large end diameter - small end diameter / axial length of the cone, then the taper of a large tapered workpiece = D2 - D1 / L2 - L1.
[0040] Preferably, based on the requirements of detection accuracy and detection content, multiple cross-sections of the large conical workpiece are selected to re-inspect the taper of the large conical workpiece at each stage.
[0041] Preferably, the concentricity of the taper is evaluated by projecting the circumferential centers of each section of the large conical workpiece onto the end face and then assessing the deviation of the projection of the center of each section.
[0042] By using this testing fixture and method, high-precision taper measurement of large conical workpieces can be achieved using precision optical testing equipment such as laser tracking testing systems. This fixture and testing method can be widely used in the manufacturing and maintenance precision testing of equipment in industrial fields such as metallurgy, aviation, shipbuilding, and power generation. It greatly expands the range of high-precision testing parameters for workpieces using optical testing equipment such as laser tracking testing systems, improves the accuracy and efficiency of taper testing of large conical workpieces, reduces the workload of testing, lowers testing costs, and avoids potential quality problems.
Claims
1. A tool for checking the taper of a large conical workpiece, characterised in that: It includes an end face fixing unit, an axial extension unit, an acquisition unit, and a length calibration unit; The end face fixing unit includes a smooth rectangular plate and an extension rod. The rectangular plate is located at the top of the extension rod, and the bottom of the extension rod is provided with a mounting hole. The axial extension unit includes an extension rod, one end of which is connected to the mounting hole of the extension rod of the end face fixing unit, and the other end is connected to the acquisition unit; The acquisition unit includes a connecting rod, a measuring rod, a measuring base, a measuring target ball, and a fixing clamp. One end of the connecting rod is threaded to the extension rod of the axial extension unit, and the other end has a through hole perpendicular to the axial direction. The measuring rod passes through the through hole of the connecting rod. The fixing clamp holds the measuring rod and fixes it in a fixed position relative to the connecting rod. The measuring base is located at one end of the measuring rod, and the measuring target ball is located at the measuring base. The other end of the measuring rod is a cone, and the top of the cone makes point contact with the cone surface of the large conical workpiece. The length calibration unit is a precision plate with a conical hole in the center, which matches the cone of the measuring rod of the acquisition unit.
2. The taper detection fixture for large conical workpieces according to claim 1, characterized in that: The extension rod of the end face fixing unit, the extension rod of the axial extension unit, and the measuring rod of the acquisition unit are each composed of multiple rod segments connected by threads.
3. The cone detection tooling for large conical workpieces of claim 1, wherein: The surface flatness of the precision plate of the length calibration unit is 0.01 mm. The depth of the conical hole is calibrated in the laboratory using a benchtop coordinate measuring machine. The distance deviation caused by the cone of the measuring rod being placed in the conical hole and the cone of the measuring rod being placed on the surface of the precision plate is detected by a laser tracker.