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:
Feb. 13, 2001
Filed:
Jun. 15, 1998
Mitsunori Nishimura, Hitachinaka, JP;
Hidefumi Adachi, Mito, JP;
Yoshikatsu Hashimoto, Hitachiohta, JP;
Hitachi, Ltd., , JP;
Abstract
A throttle valve is rotatably mounted to a throttle body through a throttle shaft. An internal bore shape of the throttle body is of a straight bore type having a shape in which the center of rotation of the throttle valve is placed on the central line of the throttle body. Spherically-shaped internal profile portions are provided in an idle control region lying in the neighborhood of a fully-closed angle of the throttle valve. Further, spherically-shaped internal profile portions are provided as regions following the spherically-shaped internal profile portions referred to above. Moreover, regions each formed by a spherical shape and a composite surface profile of a cylindrical surface substantially parallel to the flow of intake air or regions each formed by a conical surface profile are provided as regions following the spherically-shaped profiles. Incidentally, the center of each spherical profile is offset on the central line of the bore in upward and downward directions. As a result, a clearance defined between each spherical profile and the throttle valve increases as the degree of opening of the throttle valve increases. When the present invention is used in an electronically-controlled type throttle valve control device, the engine speed is set so as to be changed 20 rpm when the throttle valve is opened 0.1° in a low degree-of-opening region of the throttle valve. Therefore, idle control exercised by an ISC valve is unnecessary.