2011 Fiscal Year Final Research Report
Research on shaping of burr less gear by cold extrusion through reducing after expansion workpiece diameter
| Project/Area Number |
20560104
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Production engineering/Processing studies
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| Research Institution | Shizuoka University |
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Principal Investigator |
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| Project Period (FY) |
2008 – 2011
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| Keywords | 成形加工 / 冷間押出し / 平歯車 / はすば歯車 / 内歯車 / 鍛流線 |
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| Research Abstract |
When extruding a gear while confining the outer diameter of the workpiece, burr-like irregularities occur on the end surface of the shaped form although the pressure(load) is low. When extruding a gear while expanding the inner diameter of the workpiece, the irregularities on the end surface become smaller but the load becomes greater. A shaping experiment was conducted in this study to take the respective advantages of the above two approaches by adopting a procedure of extrusion after expansion. The intention was to obtain a shaped form having small burr-like irregularities with a low load, and eventually produce gears using only a press line
First, it was found possible to form gears using the above method. The lower limit of cross sectional reduction in area to obtain a favorable gear was determined. The needed pressure of the punch, mandrel, and die is far below the strength of the punch, mandrel, and die materials. The burr-like irregularities on the end surface could be reduced in size compared with the two-step extrusion method, which has been proposed for gear shaping, but could not be eliminated completely
It was found that the irregularities could be rectified with a press machine because of their reduced size
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