M.S. Thesis Presentation by Charoenchai Khompatraporn
Wednesday, February 17, 1999

(Dr. Steven Liang, advisor)

"Wear Force and Degree of Tool Wear Prediction Using Cutting Force Signature in Valveseat Machining"


A valveseat is a metallic seat valve used in controlling the intake and exhausted air in and out of a combustion chamber in an internal combustion engine. Because variations in dimensions of the valveseat can greatly effect the ignition reaction in the combustion chamber, the valveseat must be machined in tight tolerance so that the finished valveseat has exact dimensions as it was designed.

Valveseat machining is currently suffering from a tool wear problem. Tool wear is not desirable because it can damage final dimensions of the valveseat. This thesis presents an investigation in finding the relationship between the cutting forces and the wear on the cutting tools. The relationship was modeled using mathematical equations. The validation of the model was conducted by comparing the experimental cutting forces to the computer simulated forces. The force simulation program was written based on the mathematical equations developed. A mean to estimate the degree of tool wear when the cutting forces are known was also initiated. Tool wear estimation here was, in fact, a reverse model of the cutting force model mentioned above.