A new trochoidal pattern for slotting operation

Slotting is a common machining operation in manufacturing. Trochoidal milling is a good strategy for slotting, owing to its reduced cutting force load and better heat dissipation, which help significantly prolong the tool service life. Nevertheless, the traditional circular type trochoidal milling suffers from a longer total machining time due to its unfavorable chip removal rate. As an improvement to this quandary, a new type of trochoidal pattern is proposed in this paper, which is applicable to an arbitrary complex slot with a curved boundary and varying width. This new type is more flexible to adjust, unlike the conventional circular type whose adjustment margin is severely limited. Then, towards the objective of minimizing the total machining time, optimization is performed to find the best tool path of the new trochoidal pattern for the given slot, subject to the given threshold on the maximum cutter-workpiece engagement angle which is the key to gauge the heat dissipation and cutting force. Both computer simulations and physical cutting experiments are conducted and the results have confirmed the intended advantages of the proposed new type of trochoidal pattern over the traditional circular type.