The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 11, 2000
Filed:
Jul. 09, 1997
Koichiro Hayashi, Matsudo, JP;
Katsunao Chikahata, Matsudo, JP;
Hitachi Powdered Metals Co., Ltd., Chiba-ken, JP;
Abstract
Disclosed is a valve guide which is manufactured by a sintered alloy and used for an engine, and more particularly, to a valve guide which has high wear resistance and can prevent appearance of scuffing on a surface of a valve stem associated with the valve guide, and to a process for manufacturing the valve guide. The valve guide comprises an inner surface sliding with a valve stem, the inner surface finished by machining and exposing pores. Area-ratio of the pores with respect to the inner surface is 2.7 to 10.7%, and at least one pore having pore size of not less than 80 .mu.m exists per 1 mm.sup.2 of the inner surface.