Koichi Taguchi

Study on Deep-hole Boring by BTA SystemSolid Boring Tool

The guide-pads of BTA system solid boring tools counterbalance the cutting force produced on cutting edge, and the wall surface of drilled hole is burnished by the guide-pads under supporting forces. In this paper, the property of forces acting on tool is analized and the effect of guide-pads location on it is discussed. The drilling torque can be divided into the real cutting component on cutting edge, the frictional component in proportion to real cutting torque and the burnishing component not proportional to it. The relationship between the magnitude of the forces on the supporting pads and their locations are discussed. The locations of guide-pads, where stable cutting can be performed, are analytically obtained. From the analysis and the experiments, it is concluded that the drilling torque, the amount of the oversize of hole and the roundness error are increased when the location of first guide-pad is shifted towards the cutting edge.