1988 Fiscal Year Final Research Report Summary
Direct Observation of the Micro-Plasto-Hydrodynamic Lubrication Mechanism at the Interface between Workpiece and Die by Microscope
| Project/Area Number |
62460083
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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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 | Yokohama National University |
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Principal Investigator |
KUDO Hideaki Yokohama National University, Professor, 工学部, 教授 (90017848)
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| Co-Investigator(Kenkyū-buntansha) |
TSUBOUCHI Masao Yokohama National University, Assistant, 工学部, 助手 (20017908)
AZUSHIMA Akira Yokohama National University, Associate Professor, 工学部, 助教授 (30111462)
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| Project Period (FY) |
1987 – 1988
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| Keywords | micro-plasto-hydrodynamic lubrication / drawing / direct observation / FEM / 封入潤滑油 / 画像処理 / 潤滑油粘度 / 凹部形状変化 |
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| Research Abstract |
A newly developed sheet drawing experimental apparatus which consists of a transparent die made system of quatrz, amicroscope with a CCD video camera and a video system is used to observe directly the lubricant behavior trapped in the pockets on the workpiece surface. The specimen sheets of aluminum are provided with uniformly destributed pyramidel indentations and drawn at a constant speed with oils having various viscosities. If the oil is completely trapped in the surface pockets, the geometry shows little change, while without oil in the pocket it changes markedly. This indicates that a high hydrostatic pressure is generated in the oil trapped completely in the pocket. From a FEM calculation of an axi-symmetric ypsetting of a cylinder having a central conical impression filling with oil, it is also shown that the hydrostatic pressure in the oil approaches the normal pressure acting on the real contact area at about 5% reduction in height of the cylinder. Moreover, even permeation of the highly pressurized oil in the pocket into the real contact area is directly observed. For the oil having lower viscosities the oil in the pocket permeates forward into the real contact area, and the shape change becomes larger. The oil with higher viscosities is squeezed much more backward than forward. From the above results, the existence of the micro-plastohydrodynamic lubrication mechanism is confirmed.
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Research Products
(4 results)
