Research Of Camshaft Grinder CNC System Based On HNC-8

With the rapid development of industry, camshaft, as one of the important parts of the automobile engines, textile machinery, packaging machinery, the improvement of its precision and processing efficiency has become a serious problem. Due to the high hardness of the camshaft's surface, the main way to process the camshaft is grinding. Domestic traditional camshaft grinding machines are routing machines. With the rapid development of modern manufacturing technology, there has been a number of domestic machine tool manufacturer producing NC camshaft grinder, but these camshaft grinder almost all use overseas numerical control system. At present, there isn't a mature CNC system domestic suitable for the camshaft grinding machine, therefore, it is very necessary to develop a domestic Camshaft Grinder CNC system. This article is based on HNC-8 CNC system aiming to develop a Camshaft Grinder CNC system. The main contents are as follows:Firstly, Based on having analyzed the structure of the camshaft grinding machine and its working principle and based on that studied the hardware configurations of the camshaft grinding machine CNC system and its overall control scheme of the software. The paper made an intensive study of the algorithm to get the cam's actual profile by its lift table, the size of the follower and the base circle of the cam, as well as the algorithm to get the contact points of the grinding wheel and the cam with the grinding wheel's diameter and additionally studied the algorithm to get the C axis speed profile when grinding at an almost constant speed. Then the paper implemented these algorithms with the C ++ programming language.Secondly, based on HNC-8 CNC system underlying robot functions, the paper studied and implemented to make the X-axis following the motion of the C-axis by the data of the servo table. At PLC module of the CNC system, the paper developed the shock grinding function, combined with the P7 wb measuring instrument developed the Eliminating blank range function and the anti-collision function, and also studied the optimization of the C-axis speed curve when grinding at an almost constant speed. In addition, the paper studied the cam profile error when the grind wheel diameter get smaller but still follow the C-axis at the original following table.Finally, the paper designed and programmed the man-machine interface of the camshaft grinder CNC system and on the developed CNC camshaft grinding machine, did experiments such as the dressing of the grinding wheel and camshaft grinding. The paper analyzed the precision of the grinded cam and put forward specific methods to improve the accuracy of the camshaft grinding.