Views: 0 Author: Site Editor Publish Time: 2022-09-02 Origin: Site
The development of gear measurement technology has a history of nearly a hundred years. Corresponding to gear accuracy standards, modern gear measurement techniques can be classified into the following three types:
1. Measurement technology of single-item geometrical error of gears
It adopts the coordinate geometric analysis measurement method, and regards the gear as a geometric entity with complex shape. On the established measurement coordinate system (rectangular coordinate system, polar coordinate system or cylindrical coordinate system), the gear tooth surface is measured according to the design geometric parameters. The geometrical deviation is measured.
There are two main measurement methods: discrete coordinate point measurement method and continuous geometric trajectory point scanning (such as generation) measurement method. The measured gear error is the actual position coordinate (actual trajectory or shape) of the measured point on the gear tooth surface under test and the theoretical position coordinate (theoretical trajectory or shape) of the corresponding point on the ideal gear tooth surface established according to the design parameters. The difference between them is usually the difference between the measurement trajectory formed by the corresponding measurement movement of the geometric coordinate gear measuring instrument. The measured error item is the single geometric deviation of the gear, mainly three basic deviations such as tooth profile, tooth direction and tooth pitch.
In recent years, due to the development of coordinate measurement technology, sensor technology and computer technology, especially the enhancement of data processing software functions, the measurement of error items such as three-dimensional tooth profile deviation, single-item geometric deviation of decomposed gears and spectrum analysis has been popularized.
The advantage of single-item geometric deviation measurement is that it is convenient to analyze and diagnose the processing quality of gears (especially the first piece), and to readjust the processing parameters of the machine tool; the instrument can be corrected with the help of the template to realize the transmission of the benchmark.
2. Gear comprehensive error measurement technology
It adopts the meshing and rolling comprehensive measurement method, and regards the gear as a transmission element of rotary motion. Under the theoretical installation center distance, it meshes and rolls with the measuring gear to measure its comprehensive deviation. The comprehensive measurement is divided into gear single-sided meshing measurement, which is used to detect the tangential comprehensive deviation and single-tooth tangential comprehensive deviation of the gear; and gear double-sided meshing measurement, which is used to detect the radial comprehensive deviation of the gear and the single-tooth radial comprehensive deviation. deviation.
In order to play a more effective role in the quality monitoring of the gear double-sided meshing measurement technology, the deviation spectrum analysis measurement item has been added. In recent years, the radial comprehensive helix angle deviation and the radial comprehensive tooth taper deviation have been decomposed from the radial comprehensive deviation. This is a new development in gear radial comprehensive measurement technology.
The advantage of comprehensive motion deviation measurement is that the measurement speed is fast, it is suitable for the final quality inspection of batch products, and it is convenient to monitor the gear processing process in time. The instrument can be calibrated with the help of standard components (such as standard gears) to realize the transmission of the reference.
The above two measurement technologies are based on the traditional gear accuracy theory. However, with the continuous increase and improvement of gear quality inspection requirements, these traditional gear measurement technologies are also continuously refined, enriched, updated and improved.
3. Gear overall error measurement technology
The gear overall error theory it is based on is a new type of gear measurement theory created and continuously improved by the scientific research and technical personnel of my country's machine tool industry, especially the Chengdu Tool Research Institute. Take the gear as a geometric entity for realizing the transmission function, or use the coordinate geometric analysis method to measure its single geometric accuracy, and integrate it into a "static" gear overall error curve according to the gear meshing transmission sequence and position; The single-sided meshing comprehensive measurement method uses a special measurement gear, and the rolling point scanning measurement method is used to measure it, and the overall error curve of the gear "movement" is obtained.
The overall error curves of the above two gears can be obtained through calculation and data processing to obtain the comprehensive motion deviation of the gear, the geometric deviation of each individual item, the three-dimensional tooth surface topography deviation, and the state of the contact area, so as to evaluate the gear quality and accuracy more comprehensively and accurately. Analysis and diagnosis of gear machining processes.
Gear overall error measurement technology is the inheritance and development of traditional gear measurement technology. In particular, the gear overall error measurement technology using single-sided meshing and rolling point scanning measurement has the characteristics of rich measurement information, fast measurement speed, and measurement accuracy closer to the use state, especially suitable for batch product gear accuracy detection and quality control.
Under the situation that automobile gears require 100% inspection, this kind of gear overall error measurement technology first developed in my country has been valued and promoted. Among them, the bevel gear overall error measurement technology developed by Chengdu Tool Research Institute was transferred in the 1990s. To the German company KLINGELNBERG. The gear single-side meshing rolling point scanning measuring instrument introduced to the market by German FRENCO in recent years adopts a completely similar technology.
A development trend of the current gear manufacturing industry is to integrate gear measurement technology with gear design, processing and manufacturing, and realize the fusion of gear manufacturing information and the integration of CAD/CAM/CAT, so as to build an advanced gear closed-loop manufacturing system (due to the usual It is realized by digital information, which can be called digital closed-loop manufacturing system). The closed-loop manufacturing technology and system of bevel gears developed by GLEASON in the United States and KLINGELNBERG in Germany is a typical example.
In addition, in terms of instrument measurement form and detection system, modern gear measurement technology has the following progress.
4. Gear on-machine measurement technology
This technology has developed rapidly in recent years and is an important development trend. The gear measuring device is directly integrated into the gear processing machine tool, and the gear does not need to be disassembled after trial cutting or processing. On-machine measurement is immediately performed on the machine tool, and the parameters of the machine tool (or roller) are adjusted and corrected in time according to the measurement results (mainly for gear grinding). This is especially significant in terms of improving production efficiency and reducing costs for forming and gear grinding. The CNC gear grinding machine of KAPP factory in Germany is a typical representative. The rapid development of CNC gear processing machine tools provides a reliable working platform for promoting the application and development of gear on-machine measurement technology.
Due to the improvement of the quality requirements for mass-produced automobile and car gears, the application of gear online measurement and sorting technology has become indispensable. In recent years, Shanghai Automobile Gear Factory has introduced this technology and corresponding equipment from ITW Company in the United States for the first time, and achieved the expected results.
5. Gear Laser Measurement Technology
Usually refers to the use of laser technology in the measurement of the geometric size and shape position accuracy of the gear, including the use of a laser length measuring system (such as using a dual-frequency laser interferometer as the length reference or sensor of the gear measuring instrument), laser measuring head system (such as using a non-contact point reflection laser measuring head as a detection sensor for gear errors), and a laser holographic gear measurement system (such as a system that uses laser holography technology to measure the geometric error of the gear tooth surface), etc.
Since laser is the reference for length traceability, many high-precision gear measurement systems or gear measurement reference instruments use laser measurement systems as their length coordinate measurement systems. The MICROLOG60 developed by the FELLOWS factory in the United States in the 1970s is an example. The gear measuring instrument produced by the Windsor Precision Measuring Instrument Factory in Canada in the early 1980s used a non-contact point reflection laser measuring head, which can be used to measure the soft tooth surface gear made of plastic.
In recent years, gear laser measurement technology has received much attention in Japan, and it has been gradually perfected and introduced to the market. The G3 gear measuring system of Japan AMTEC company adopts the CONO laser measuring head, the gear rotates, the position of the measuring head changes accordingly, and the cross-sectional shape of the gear is measured. The laser gear measuring instrument developed by Osaka Seiki uses laser holography technology to accurately measure the shape of the entire tooth surface of the measured gear by optical interferometry.
