RECOGNITION OF WOOD CUTTING CONDITIONS TH ROUGH CUTTING SOUNDS .2. RELATIONSHIPS BETWEEN CHIP FORMATIONS AND CHARACTERISTICS OF CUTTING SOUNDS IN 90-0-CUTTINGS, 0-90-CUTTINGS, AND 90-90-CUTTINGS

To clarify the relationships between cutting sounds and types of chip formations during orthognal cutting of hinoki (Chamaecyparis obtusa En dl.) in 90-0, 0-90, and 90-90 cutting directions, cutting sounds and c utting-system vibrations were measured. Cutting tests were performed o n four depths of cuts (0.05-0.3 mm) and six cutting angles (30-80 degr ees), keeping cutting speed constant at 1 m/s with a whirling disc-mac hine. The following results were obtained: 1) Cutting sounds in the lo w-frequency range (0-6 kHz) are affected much by the cutting-system vi brations generated by variations of cutting resistance. Also, in this frequency range, frequency characteristics of cutting sounds almost ag ree with the frequency characteristic of the cutting-system vibration except to generate a split type of chip formation in the 90-0 cutting. 2) It is considered that cutting sounds in the ultrasound range (20 k -100 kHz) have effects of other things than effects of the cutting-sys tem vibration as a sound source, because increasing tendencies of soun d pressure levels are different from cutting sounds in the low-frequen cy range. 3) Power spectra of cutting sounds in 90-0 cutting indicated particular patterns for different types of chip formations. It is the refore possible to recognize types of chip formations by use of spectr a patterns of cutting sounds. 4) It seems that the use of power spectr a of cutting sounds in 0-90 and 90-90 cuttings are difficult to recogn ize types of chip formations.