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:
Dec. 15, 1992
Filed:
Mar. 06, 1992
Junichi Kano, Kariya, JP;
Atsushi Sato, Kariya, JP;
Aisin Seiki Kabushiki Kaisha, Kariya, JP;
Abstract
A valve opening and closing timing control apparatus is disclosed, which includes an engine including a cam shaft and a crank shaft, a first sensor adapted for detecting rotary positions of the cam shaft, a second sensor adapted for detecting rotary positions of the crank shaft, a first hydraulic pump and a second hydraulic pump driven by the crank shaft, a hydraulic pressure switching valve disposed between a discharge port of the first hydraulic pump and a discharge port of the second hydraulic pump and communicating therewith, a rotary phase varying device disposed on the cam shaft and adapted for varying rotary phases of the cam shaft, a hydraulic line connecting the hydraulic pump and the rotary phase varying device, a hydraulic control device disposed iin the hydraulic line, and an electronic control device adapted for controlling the hydraulic device and receiving output signals which are output by the first sensor and the second sensor at least, thereby operating the rotary phase varying device with the hydraulic control device under linear control. The valve opening and closing timing control apparatus can establish the valve opening and closing timing at optimum and desired occasions, which distinguishes over the conventional digitized valve opening and closing timing. Moreover, the engine driving losses can be suppressed because the hydraulic pressure switching valve bypasses the hydraulic pressures when the rotary phase varying device requires no hydraulic pressure.