Generating CBN Grinding of 3 Dimensional Curved Surface of Machine Parts

Research Project

Project/Area Number	01550116
Research Category	Grant-in-Aid for General Scientific Research (C)
Allocation Type	Single-year Grants
Research Field	機械要素
Research Institution	Kyoto University
Principal Investigator	KUBO Aizoh Kyoto Univ., Dept. Prec. Mech., Asst. Prof., 工学部, 助教授 (10027899)
Co-Investigator(Kenkyū-buntansha)	FUJIO Hiroshige Kyoto Univ., Dept. Prec. Mech., Instructor, 工学部, 助手 (90026097) KAKINO Yoshiaki Kyoto Univ., Dept. Prec. Mech., Prof., 工学部, 教授 (00026204)
Project Period (FY)	1989 – 1990
Project Status	Completed (Fiscal Year 1990)
Budget Amount *help	¥2,000,000 (Direct Cost: ¥2,000,000) Fiscal Year 1990: ¥300,000 (Direct Cost: ¥300,000) Fiscal Year 1989: ¥1,700,000 (Direct Cost: ¥1,700,000)
Keywords	Hard Finishing / Grinding / CBN Grinding / Gear Quality / grinding / CBN grinding / gear quality
Research Abstract	The grinding velocity and feeding velocity at generating grinding, for instance in the case of generating grinding of gear tooth flanks, cannot be selected independently and the absolute value of grinding velocity is in general very slow. This is a big difference from the conventional grinding such as cylindrical grinding. The basic grinding test of case hardened specimen under constant pressure using disk type CBN grinder under slow grinding speed reveals, that the amount of removal by constant grinding distance is (1) independent from the grinding velocity, (2) proportional to the grinding pressure and (3) it increases with increasing rolling velocity. Three kinds of failure of CBN grinder were found during the test : (1) Failure of Nickel Bond by scratching of specimen, (2) Covering of CBN crystal by the material of specimen and (3) fracture of CBN crystal due to high contact pressure of impulse. The simulation program of tooth flank grinding using CBN grinder of gear wheel shape was developed using the results of the fundamental nature of constant pressure and slow speed CBN grinding mentioned above. The simulation shows the pressure distribution which acts on the CBN grinder during operation and the form accuracy of tooth flank of manufactured gear. These results can be obtained as functions of dimensions and form accuracy of grinding wheel and of operating condition of grinding. The results of the simulation show that the setting of high-feed or of large grinding pressure at the operation of grinding induces the deterioration of tooth form accuracy. The results were discussed by comparing the results of simulation and those of CBN ground gear using Hurt-type gear grinder.