Building on hard turning: Not all machines are constructed for hard-turning operations

摘要

The benefits of hard turning are compelling: fast metal-removal rates, the flexibility to handle small batches and complex shapes, and a relatively low-cost tooling inventory versus the grinding process. But the results of machining are as varied as the systems used. The more demanding the application in terms of finish, roundness, and size control, the more important are machine qualities such as dynamic stiffness, motion capability, and accuracy. Machines with low levels of vibration over a wide frequency range are best suited for hard turning. Typically, they have high dynamic stiffness - a measure of the ratio of the applied force to the displacement, which occurs at the frequency of the exciting force. For the most part, dynamic stiffness dictates the upper bound in achievable part quality, and this is what makes it important.