| Budget Amount *help |
¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 1999: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1998: ¥1,400,000 (Direct Cost: ¥1,400,000)
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| Research Abstract |
1. IN TE CASE OF CUTTING WITH REDUCD CONTACT TOOLS AND WITH CHAMFERED EDGE TOOLS HAVING LARGE NEGATIVE RAKE ANGLE, CUTTING MODELS IN WHICH TE MODE OF DEFORMATION IS APPROXIMATED WITH THE VELOCITY DISCONTINUITY LINES ARE DEVELOPED. BY APPLYING ENERGY METHOD TO THESE CUTTING MODELS, PREDICTED RESULTS ARE IN GOOD AGREEMENT WITH EXPERIMENTAL RESULTS.
2. THE CUTTING MODELS ARE ABLE TO EXPLAIN THE TRANSITION OF CHIP FORMATION PROCESS FROM INVOLVING SECONDARY CHIP TO INVOLVING BURRING WITH RAKE ANGLE AND FRICTIONAL CONDITION ON THE RAKE FACE. BASED UPON THE DATA PREDICTED FROM THE MODELS, CUTTING TEMPERAYURE IS CALCULATD USING FINITE ELEMENT METHOD. FOR PLAIN CARBON STEEL (JIS S48C), THE SECONDARY CHIP CONTINUES TO EXIST EVEN IN TE CONDITION WHERE THE CUTTING TEMPERATURE ALONG THE RAKE FACE REACHES 1000℃ AT HIGH CUTTING SPEEDS. ACCORDINGLY IT IS CONSIDERED THAT THE DISAPPEARANCE OF THE SECONDARY CHIP DEPENDS ON THE CONDITION OF STATIC EQUILIBRIUM, BUT DOES NOT ON THE CUTTING TEMPERATURE.
3. IN THE CASE OF CUTTING WITH TOOLS HAVING THREE RAKE SURFACES, THAT IS, CAMFERED EDGE AND ARTIFICIALLY CONTROLLD TOOL-CHIP CONTACT LENGTH ON THE SECONDARY RAKE FACE, CUTTING MODELS ARE DEVELOPED. TEREFORE IT IS FOUNF THAT THE GENERATION OF THE SEONDARY CHIP IS INFLUENCED BY THE COMBINATION OF THE PRIMARY AND SECONDARY RAKE ANGLES AND FRICTIONAL CONDITION ON THE SURFACE OF CHAMFERED EDGE. USING THE EXPERIMENTAL DATA OF REDUCED CONTACT TOOLS, PREDICTED RESULTS ARE IN GOOD AGREEMENT WITH EXPERIMENTAL RESULTS.
4. FOR CUTTING STEEL OF S48C, IT IS FOUND THAT LARGE CHAMFERED EDGE GIVES STRENGTH FOR GROSS FRACTURE AND EDGE CHIPPING, BUT WEAR-LAND WEAR INCREASES WITH THE LENGTH OF THE CHAMFERED EDGE. IN THE REGION OF THE CUTTING SPEEDS PRODUCING SECONDARY CHIPS, GOOD SURFACE ROUGHNESS IS OBTAINED, BUT A PRIMARY RAKE ANGLE OF -60°GIVES BURNISHING AND BURRING.
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