Taking the automobile industry as an example, deep hole drilling is often the main technological means in hole processing, and hole processing is often an important process in the automatic production line of key parts of automobile. Due to the existence of systematic error and random error, the quality and efficiency of professional deep hole drilling are greatly affected. Deep hole drilling error compensation technology has become the core technology of developing such automatic production line.
From the point of view of the way to generate micro displacement, there are two ways to compensate the drilling error: one is to use some special mechanisms, such as eccentric type and swashplate; the other is to use the elastic deformation of the cutter rod or cutter clamp, such as differential thread type and elastic cutter clamp type.
There are many mechanical transmission links in the compensation mode, and the possibility of error is great, so the application in precision compensation is limited. The problem is: in order to avoid dynamic vibration in cutting, it is necessary to improve the rigidity of the joint, so the driving force of the feed motion is correspondingly increased.
The elastic deformation of the cutter bar can be divided into two types: the inclination of the cutter bar axis relative to the spindle axis (such as differential thread type) and the displacement (such as parallelogram mechanism). Its remarkable feature is that there is an elastic connection between the spindle and the cutter bar. Generally, the elastic tool holder is driven by the inclined block to produce elastic deformation, so as to realize the radial compensation of the tool tip. Because of the elastic deformation of the tool holder, not only the compensation linearity is better, but also the driving force required is much smaller than the deformation of the tool bar, which can reduce the unnecessary deformation of the whole transmission link.