Characteristics of sawing force location in the unsteady stage

Abstract

Although the unsteady sawing stage, an integral part of the complete sawing process, contains the characteristics of the sawing process, few studies have been carried out due to the complexity of processing. In the present work, the varying characteristics of sawing force location were studied based on the cut-in and cut-out unsteady stages. Through using kinematic method, the force location can be calculated based on the measured horizontal and vertical force components converted to the tangential and normal force components. Corresponding experiments were undertaken on a precision sawing machine at a large range. Based on the experimental results and analysis, it is found that the force location increases with the increase of the instantaneous length of contact zone, but it decreases with the increase of depth of cut. The workpiece feed speed and sawblade speed have an influence on the force location. When the instantaneous length of contact zone is close to that of the maximum contact zone, the force location basically acts at 0.6 apart from the bottom of the contact zone, which is due to the shifting behaviour of sawing swarf.