It is significant to improve gear machining accuracy and efficiency by improving tool setting accuracy and efficiency of gear grinding machine. The gear grinding machine can adjust the tool automatically without stopping the machine, and the operation is simple, high efficiency and high precision. The main idea of automatic and accurate tool setting is as follows: the CNC system automatically obtains the tooth groove boundary on both sides of the workpiece and records its position, and then calculates the exact position of the tooth groove middle point, which is the starting point of feed processing. Finally, the servo system issues instructions to determine the position of the grinding wheel. Therefore, how to quickly and accurately obtain the groove boundary position is the key of automatic and accurate tool setting technology.

Using the contact detection technology, coordinate calculation with the spindle, can quickly and accurately obtain the position of the tooth slot, and finally determine the specific position of the tool. At present, the most important contact detection technology can be summarized as follows: spindle motor power detection, torque detection and AE acoustic signal detection. Foreign research on automatic tool setting technology of gear grinding machine started earlier, and the technology is relatively mature. High-end gear grinding machines such as German KAPP, NILES and Swiss RE-ISHAUER can realize automatic and accurate tool setting function. Domestic relevant studies started late and progressed slowly. Representative studies are as follows. Qinchuan Machinery Development Co., LTD., drawing on the tool setting technology of foreign gear grinding machines, proposed the use of AE AE technology for contact detection, assisted the coordinate detection and calculation of machine tool, and realized the automatic tool setting function of rough grinding and fine grinding of cylindrical internal gear with single sheet forming wheel, as well as the anti-collision function. The tool mark is within 0.01mm, meeting the production requirements. Liu Haining et al. from Nanjing University of Technology also used AE sensor to detect grinding acoustic signals, and analyzed and processed by electric control box as feedback signals. The method is applied to SINUMERIK840D NC system, and the precise automatic tool setting of worm grinding wheel is realized.