摘要 |
The invention has an object to provide a bolt-hole work process for forming bolt holes in a flange of a hub unit bearing. Cores 1w are formed at multiple places circumferential of a flange 1f of an outer race 1 of the hub unit bearing. The cores 1w are punched by a punching press 11, 12, 13 and then are directly serrated by a serration punching press 31, 32, 33 for forming serrated holes 1p. Alternatively, the cores are formed with chamfers 1h, k, i at their respective opposite circumferential edges and then are serrated by the serration punching press utilising a female die with die holes and serrating punches so as to be formed with serrated holes therein.
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申请人 |
KOYO SEIKO CO., LTD., OSAKA, JP |
发明人 |
KASHIWAGI, SHINICHIROU, YAO, JP;MIYATA, YASUHIRO, YAMATOKORIYAMA, NARA, JP;MINAMI, YOSHIYUKI, KASHIWARA, JP;MORIMOTO, SHINJI, KASHIBA, NARA, JP |