The influence of cutting speed and feed-rate on circularity and surface roughness of machined valve seats in serial production

Francisco Bonardi Filho¹; Gustavo Santos¹; Silvio Vannunci¹; Milton Luiz Polli¹

¹ UTFPR

doi:10.20906/CPS/COB-2015-1020

Resumo

The machining of valve seats is essential for proper engine performance, once correct seating of the valves assures the correct sealing. Valve leakage will adversely affect the engine compression ratio and therefore the engine efficiency. The machined valve seats must comply with the roundness and roughness project requirements. This work investigates the influence of cutting speed and feed-rate on the boring of valve seats of internal combustion engines using polycrystalline cubic boron nitride (PCBN) tools in serial production. This study takes in consider the process capability and process performance Ppk index. It was observed that higher cutting speeds result in higher roundness variations. Besides, as the feed-rate increases the surface roughness variations decrease. The best results were found for the cutting speed of 55 m/min and feed-rate of 0.15 mm.

Palavras-chave: valve seats; machining; surface roughness