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. 06, 1987
Filed:
Aug. 31, 1984
Mark L Haddox, Ann Arbor, MI (US);
Jodon Engineering Associates, Inc., Ann Arbor, MI (US);
Abstract
A method and apparatus for measuring compression ratio and/or clearance volume in an internal combustion engine cylinder wherein the crankshaft angle associated with piston top dead center position is obtained and cylinder pressure is measured at a number of incrementally spaced piston positions. Changes in cylinder volume between the incrementally spaced piston positions are determined from nominal engine design parameters. These multiple pressure and volume figures are then employed in a programmed microprocessor to determine the constants .gamma. and k in the polytropic equation for relating cylinder pressure to volume PV.sup..gamma. =k. Clearance volume V.sub.TDC is determined using the constants .gamma. and k, and measured pressure at TDC or incremental volume figures. Compression ratio is determined by the fraction (V.sub.DP +V.sub.TDC)/V.sub.TDC, where V.sub.DP is total piston displacement volume obtained from nominal engine design parameters. The invention is also implemented to determine cylinder leakage during the compression stroke, angles of operation of the intake and exhaust valves, effective compression ratio where the intake valve does not close at BDC, and/or cylinder intake pressure.