Current situation and development of the hottest g

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The present situation and development of gear measuring instruments (II)

although the gear measuring centers in various countries are similar in principle, there is a certain gap in the implementation method. It is mainly manifested in:

(1) in terms of measuring sensors, although high-precision circular gratings are generally used for angle measurement, the measurement length varies due to different measured objects. For gears with high accuracy requirements or workpieces with long axial dimensions, dual frequency (or single frequency) laser interferometers are generally used as length Benchmarks (such as measuring involute or helix templates); In other cases, high-precision long gratings are used

(2) in terms of the accuracy of mechanical systems, high-precision bearings are necessary; The accuracy of linear guide rail is guaranteed by mechanical accuracy, and it is also achieved by error correction technology

(3) in terms of numerical control system, NC open-loop control was often used in the 1970s; After the 1980s, it was all controlled by CNC, most of which used DC servo motor or stepping motor. At present, AC servo system or linear motor has been used

(4) in terms of probe, there are inductance type and grating type; There are one-dimensional, three-dimensional, and even rigid. Rigid probe is without micrometer sensor. If a rigid probe is used, the instrument is usually dedicated

gear measuring center is generally composed of host machine, CNC numerical control unit, data acquisition unit, inter machine communication interface, computer and peripherals, measurement software and data processing software. The main features of the latest CNC gear measuring center today are: ① high efficiency, high precision and easy operation in performance. The measures taken include the optimal design of precision machinery, 32-bit CNC axis numerical control system, linear motor, three-dimensional probe and error correction technology. ② In terms of function, it includes the measurement of main error items of rotating parts such as gears (internal and external), gear cutters (hobs, gear shapers, shaving cutters), bevel gears, worm gears, worms, screws, convex gears, broaches, etc; Compared with the more complex computer display models, the geometric tolerance measurement of shaft parts; Powerful analysis functions, such as contact analysis, process error analysis, tooth root shape analysis, parameter reverse calculation, etc; It can be coupled to the processing system for real-time data communication. ③ In terms of maintainability, it has the ability of fault self diagnosis and remote fault diagnosis. ④ Upgradeability. Including software upgradeability and hardware upgradeability

compared with mechanical generative measuring instruments, the advantages of CNC gear measuring center are self-evident. Its qualitative flying will undoubtedly continue. The incremental leap provides the possibility for the measurement of tooth profile of any shape, not limited to involute or linear tooth profile. The measurement of bevel gear, K worm (HOB) and C worm (HOB) is proof. CNC gear measuring center provides a tool for measuring and controlling nonlinear helical surfaces

Since 1990, there have been several noticeable phenomena in the field of gear measurement technology all over the world: ① gear overall error measurement technology and gear coordinate measurement technology are integrated. Chengdu Tool Research Institute has launched a gear measuring machine CZN450 with both a standard worm pair spring and other elastic components, and a probe. Foreign CNC gear measuring centers can also give "virtual overall error". ② Gear measuring center and CMM are integrated, such as rdaiance of TSK company and nd430 of process equipment company. ③ The combination of functional test and sub test. Simplified measurement is one of the development trends of gear measuring instrument. Gear overall error measuring instrument is accepted by gear manufacturing industry because it can give full information of gear efficiently

looking forward to the future, the relevant research and development priorities of gear measuring instruments are: gear Networking Measurement Technology; Virtual analysis of gear performance based on measured results, such as 43r/min6, press start keying technology (Intelligent pairing, dynamic performance prediction, etc.); Gear overall error measurement technology (index quantification, performance optimization, etc.); Intelligent analysis technology of gear error; The establishment of the concept system of gear statistical error and its corresponding measurement technology; Gear rapid measurement and analysis technology at the production site (at present, ITW's model4823 is 450 ~ 600 pieces/hour; target: 1000 pieces/hour); Application of precision machinery, photoelectric technology, microelectronics technology, software engineering and other technologies in gears

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