AN OPTIMAL TOOL REPLACEMENT STRATEGY FOR COMPUTER NUMERICAL CONTROLLED TURNING CENTERS

For a computer numerical controlled (CNC) turning centre with a multi- station tool turret, this paper describes a tool replacement strategy for tools used for both rough and finish turning, boring and facing op erations as well as other end operations which include drilling, groov ing, threading and parting-off. The method ensures a convenient replac ement strategy where tools in the machine turret are replaced after ma chining integer multiples of an optimum number of components. This opt imum number of components is determined so that the total cost due to tools and tool changing time is minimized. An example is given to illu strate how the procedure determines the optimal tool replacement strat egy. It shows that the described method can substantially reduce the n umber of interruptions due to tool replacements in processing a batch.