Invention Application
- Patent Title: Method for manufacturing a hollow rack shaft
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Application No.: US10798175Application Date: 2004-03-11
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Publication No.: US20040170401A1Publication Date: 2004-09-02
- Inventor: Akira Tsubouchi , Kiyoshi Okubo , Yasushi Watanabe
- Applicant: NSK LTD.
- Applicant Address: null
- Assignee: NSK LTD.
- Current Assignee: NSK LTD.
- Current Assignee Address: null
- Priority: JP2000-064298 20000309; JP2000-114306 20000414; JP2000-114502 20000417
- Main IPC: H04N005/781
- IPC: H04N005/781 ; B21D022/00 ; B21D022/21

Abstract:
A hollow rack shaft is manufactured through a first step, a second step and a third step. At the first step, the plate-like workpiece of substantial rectangular shape is press formed into a gutter-like shape. The first die set used at this step is provided with slant die surfaces for canceling elastic recovering generated at the workpiece when the workpiece is removed from the first die set. At the second step, a row of rack teeth is press-formed on the flat bottom portion of the workpiece formed in the first step. The die set used at the second step is provided with a recess for releasing surplus workpiece material within the die clearance at a stroke end of the pressworking. At the third step, each of a pair of legs of the workpiece is bent in a semi-circular shape so as to be butted to each other. At this time, a mandrel is inserted between the legs of the workpiece.
Public/Granted literature
- US07069764B2 Method for manufacturing a hollow rack shaft Public/Granted day:2006-07-04
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