A NOVEL TECHNIQUE FOR TENSIONING CIRCULAR SAWS USING INDUCTION HARDENING

Research Project

Project/Area Number	03452267
Research Category	Grant-in-Aid for General Scientific Research (B)
Allocation Type	Single-year Grants
Research Field	林産学
Research Institution	KYOTO UNIVERSITY
Principal Investigator	NOGUCHI Masami Kyoto Univ., Fac. of Agr., Prof., 農学部, 教授 (00026501)
Co-Investigator(Kenkyū-buntansha)	UMETSU Jiro Univ. of Ind. Technol., Prof., 教授 SAWADA Yutaka Kyoto Univ., Fac. of Agr., Instr., 農学部, 助手 (80226076) FUJII Yoshihisa Kyoto Univ., Fac. of Agr., Instr., 農学部, 助手 (10173402)
Project Period (FY)	1991 – 1992
Project Status	Completed (Fiscal Year 1992)
Budget Amount *help	¥7,200,000 (Direct Cost: ¥7,200,000) Fiscal Year 1992: ¥2,600,000 (Direct Cost: ¥2,600,000) Fiscal Year 1991: ¥4,600,000 (Direct Cost: ¥4,600,000)
Keywords	Circular saw / Tensioning / Induction hardening / Residual stress / 丸鋸 / 高周波誘導加熱 / 熱処理 / 金型
Research Abstract	To prevent thermal buckling of a circular saw during sawing, tangential tensile-stresses have been mechanically introduced into the outer zone of a saw and tangential compressive-stresses into the inner zone over a century. This processing is called TENSIONING. We proposed a theory of tensioning by heat treatment that the outer and inner zones should be subjected to tensile and compressive stresses, respectively in the case where the center of a saw evenly heated is cooled first. A pair of dies were designed for press-tempering of a saw and the saw was physically tensioned using induction hardening. Tangential residual-stresses were measured along a radius of the saw by X-ray, and the results revealed that the outer zone of the saw was stressed in tension and the inner zone was stressed in compression. Thus, the experiments successfully proved the theory of tensioning by heat treatment is valid.