Tool Life Prediction and Avoidance of Cutting Tool Breakage in CNC System
| Project/Area Number |
61550091
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
機械工作
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| Research Institution | Kanazawa University |
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Principal Investigator |
UEDA Kanji Kanazawa University, Faculty of Engineering, Professor, 工学部, 教授 (50031133)
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| Co-Investigator(Kenkyū-buntansha) |
NISHI Makoto Kanazawa University, Faculty of Engineering, Research Associate, 工学部, 助手 (00189250)
SUGITA Tadaaki Kanazawa University, Faculty of Engineering, Professor, 工学部, 教授 (70019769)
遠藤 勝義 大阪大学, 工学部, 助手 (90152008)
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| Project Period (FY) |
1986 – 1987
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| Project Status |
Completed (Fiscal Year 1987)
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| Budget Amount *help |
¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 1987: ¥200,000 (Direct Cost: ¥200,000)
Fiscal Year 1986: ¥1,000,000 (Direct Cost: ¥1,000,000)
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| Keywords | Cutting tool breakage / Tool life prediction / Fracture mechanics / Adaptive control / Interrupted machining / Avoidance of tool breakage / 工具欠損回避 / 工具欠損寿命 / 欠損回避 / 予測制御 / CNCシステム |
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| Research Abstract |
Brittle failure of the cutting edge of a tool, such as chipping, fracturing and fatigue cracking, may cause substantial damage to the tool, the workpiece and the machine tool. Extensive efforts have been focused on solving this problem from various points of view including the analytical forecast, monitoring technique and the adaptive control approach. However, an effective method preventing brittle failure has not yet been developed. Therefore, cutting conditions have inevitably been restricted for safety reasons to an underestimated level below the optimum value, and this has necessarily resulted in poor production performances. This is in contrast to gradual type failure, i.e. wear of cutting tool, which have been overcome somewhat successfully by various methods.
In this study, a new approach is proposed for adaptive control in interrupted turning where brittle failure predominates, and efficient cutting is performed by optimizing the cutting conditions within time-varying safe-limit determined on the basis of an analysis of the tool life due to brittle failure. This paper first proposes a concept for the adaptive control system, then describes an analytical prediction based on fracture mechanics of the brittle failure of the cutting edge, and discuss adaptive control experiments conducted to avoid brittle failure.
The adaptive control experiments are conducted during an interrupted CNC (Computer Numerical Control) turning operation on a plain carbon steel workmaterial using a tungsten carbide tool. It is found that brittle failure avoiance is accomplished in most cutting conditions employed, furthermore quite significant reduction in cutting time is achieved through the adaptive control system. The region where either brittle or wear-type failure can become predominant is also discussed. The proposed system is found more effective when used with larger feed rates, at lower cutting speeds, and with increased rel-cut ratios.
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Report
(2 results)
Research Products
(7 results)
