Machining crankshaft connecting rod journal by turning and milling with jinkedi

With the development of industry, the cavity, shape and accuracy of parts have been improved. The processing requirements and the beat of processing time also put forward higher requirements for processing equipment. At the same time, in order to realize the one-time clamping and processing of parts, the concept of compound turn milling came into being. As early as the late 1970s and early 1980s, a group of engineering and technical personnel were studying this model. By 1982, they had manufactured a prototype of the compound machining machine tool, which was generally considered to be four different, creating a precedent in the machining field. So far, there are many types of compound turn milling machines developed and manufactured at home and abroad and the equipment produced according to this processing principle. Their technical characteristics and processing objects have their own advantages.

For machining camshafts and large crankshafts, we hope that the equipment has better handling, multi-functional and flexible turning and milling head, and powerful anti-collision protection function. Generally, for machine tools, in addition to the advancement and stability of the NC system, the static geometric accuracy should also be reliable, stable and have long retention. The dynamic positioning accuracy should be implemented in accordance with the standard of vdi3441, especially the acceptance and assessment of repeated positioning accuracy PS. since the positioning accuracy and reverse clearance can be compensated by the NC system, Repeated positioning accuracy is the combination of manufacturing accuracy and transmission chain accuracy, which can not be compensated. The quality of machine tool manufacturing cannot be careless. We say that first-class products reflect culture and quality, and require quality and output for second-class products, while third-class products only demand quantity. At present, the manufacturing level of domestic machine tools only seeks quantity and ignores quality, resulting in their own brand. Instead of building the product series into a monument, they have become a tombstone. In the current situation, each machine tool factory should be fully aware that it will be difficult to survive without good quality and technical after-sales service.

It is required that when machining the slender shaft, the bending degree in the middle of the crankshaft can be measured during clamping, and the center frame can be compensated through the NC system. At the same time, the function of on-line measurement can be realized through the instrument during machining, and the key points to be achieved in the machining of the camshaft: the perpendicularity and runout of the two outer faces of the flange relative to the camshaft axis are 0.02mm The position degree of the two door holes on the two flanges relative to the boss axis on the same side, including the coaxiality of one hole relative to the other, the dimensional accuracy of each cam profile, and the form and position accuracy: the requirements of contour, the runout of the base circle relative to the boss axis at both ends of the camshaft, and the parallelism of the bus of the cam profile relative to the boss axis at both ends of the camshaft. Similarly, the processing of the connecting rod journal of the crankshaft should also maintain a number of requirements such as coaxiality and parallelism.