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:
Aug. 15, 1989
Filed:
Nov. 29, 1983
Helmut Denz, Stuttgart, DE;
Martin Person, Oberriexingen, DE;
Robert Bosch GmbH, Stuttgart, DE;
Abstract
The oil pressure applied to a hydraulic device for controlling within a limited angular range of a cam shaft and its drive gear is controlled by a magnetic valve (35) which is switched between its open and closed position under control of the same microcomputer which controls engine ignition and/or fuel injection with reference to a predetermined function of some of the same engine operation parameters, namely engine speed and engine load, which are used to control ignition and/or fuel injection. The control function can advantageously also take account of rate of change of engine load or engine speed. A transducer (43) for reporting back the sleeve (22) which controls the mechanical rotary shift in response to oil pressure can be used to provide an actual value signal to the computer for generation of an error signal for controlling the magnetic valve so as to provide a continuous control of the overlap of the open periods of the intake and exhaust valves of the engine. The control function for the operation of the magnetic valve provides for hysteresis to prevent excessive switching back and forth.