Title:
中空エンジンバルブの弁傘部の製造方法及び中空エンジンバルブ
Document Type and Number:
Japanese Patent JP4390291
Kind Code:
B1
Abstract:
Forming of a valve head portion (1) of a hollow engine valve (V) comprising a material particularly satisfactory in heat resistance is performed by cold forging. On this occasion, the material with excellent heat resistance is worked to form a valve head portion semifinished product (11) having a hollow hole (Sll) whose inner diameter (Æ11) is equal to the maximum inner diameter (Æ 11) of a hollow hole (Sl) of a finished product of the valve head portion (1), and having a diameter-increased section (111) whose maximum outer diameter (Æ 12) is equal to the maximum outer diameter (Æ12) of a diameter-increased section (la) of the finished product. Parts of the valve head portion semifinished product other than a central part to a lower part of the diameter-increased section (111) are necked down by cold forging performed a plurality of times to obtain the finished product of the valve head portion (1). This method of obtaining the finished product is provided by the present invention.
Inventors:
Yoshimura Tatsuharu
Application Number:
JP2008272079A
Publication Date:
December 24, 2009
Filing Date:
October 22, 2008
Export Citation:
Assignee:
Yoshimura Company, Ltd.
International Classes:
F01L3/14; B21D3/00; B21D41/04; B21J5/06; B21K1/22; F01L3/24
Domestic Patent References:
| JP2009185655A | ||||
| JP49103877A | ||||
| JP52130467A | ||||
| JP8117904A | ||||
| JP2002045935A | ||||
| JP10323735A | ||||
| JP2006088197A |
Attorney, Agent or Firm:
Kazuo Oya