Based on the actual needs of gear hobbing tools in automobile gear production line, it is transformed into seven elements of hob design. The design requirements of hob can be put forward according to these seven elements.
As a prominent performance of modern industrial production is precision, precision is the most basic classification requirement.
Therefore, gear hobbing cutter can also be divided into finish machining, semi finish machining and rough machining. Automobile gear precision hob is a kind of tool that is directly processed and formed on gear hobbing machine. This hob is mainly used in parts with special structure, which can not be used in subsequent finishing processes. Different from the fine hob, the semi fine hob is more used in automobile gears. This type of parts usually require shaving or grinding after gear hobbing to ensure the quality of products. This can reduce the difficulty of tool manufacturing and part processing, and then reduce the cost.
At the same time, the design requirements and forms of convex corner, undercutting, flat tooth root or arc tooth root, tooth top chamfering and chamfering, which need to be paid attention to in the design process of automobile gear cutter, are also discussed. More importantly, multi head hobs are also discussed, which will be a key research project to improve product processing efficiency in the future.
In addition, the inspection problems in the manufacturing process of automobile gears are also studied. There are two main inspection methods, namely single method and comprehensive method. The single inspection method only checks the basic deviation. It requires the use of special testing equipment or instruments to evaluate each deviation. The comprehensive method is mainly used for the comprehensive evaluation of automobile gear parts. External gear parts generally adopt comprehensive methods, which can more directly and accurately evaluate the quality of automobile gears. Considering the actual demand of the production site and the problem of inspection efficiency, the comprehensive method is a more comprehensive and simpler inspection method to determine the quality of automobile gear parts. However, this method can not determine which aspect of the parts is out of tolerance, so it can only be inspected one by one through a single method.
In addition, in the actual production and processing process, problems in any link of human, machine, material, method and ring will affect whether the parts are qualified in the process of mass production. Therefore, we must first ensure the correct installation of gear hobbing hob. In the process of installation, we must ensure that the runout of the cutter bar is appropriate, and the aperture matching of the cutter bar and the hob meets the requirements of relevant standards. If the gear hobbing hob is designed to be key driven, we must ensure that the single key runs through the whole hob. Finally, we must check the runout of the end face and outer circle of the hob after installation and ensure that it is qualified, otherwise it must be reinstalled. Only in this way can we ensure that the requirements of machined parts are met. It also introduces the tool shifting method of gear hobbing hob and the control of tool shifting amount, which is directly related to the wear and service life of gear hobbing hob. If the tool shifting is too fast, it will cause less parts that can be processed and waste of tools. If the tool shifting is too slow, it will cause serious tool wear. When grinding the gear hobbing tool, increase the grinding amount and affect the tool life. In order to solve this problem, on the one hand, we need to do more experiments before use to obtain the optimal cost. On the other hand, we make more records in the process of normal use. When we accumulate a certain amount of data, the result is obvious.