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:
Mar. 20, 2001
Filed:
Feb. 11, 2000
Patric Ouellette, Vancouver, CA;
Brad Douville, Vancouver, CA;
Westport Research Inc., Vancouver, CA;
Abstract
Two different fuels are injected into the combustion chamber of an internal combustion engine. A main fuel is ignited by a pilot fuel that is more readily flammable than the main fuel. According to the method, load conditions on the engine are monitored and sets of conditions are defined to constitute low load conditions and high load conditions. Distinct operating modes are defined for each set of load conditions. Under low load conditions, a homogeneous mixture of main fuel and air is too lean to be flammable; consequently, the main fuel is injected at high pressure immediately following injection of the pilot fuel. Under high load conditions, fuel is injected in three stages. In the first stage, the main fuel is injected during the intake stroke or early in the compression stroke to form a substantially homogenous mixture of main fuel and air. However, the risk of knocking limits the quantity of main fuel that can be introduced in the first stage. In the second stage, the pilot fuel is injected near top dead center and ignites the homogenous mixture of fuel and air. Since the amount of fuel that could be injected in the first stage was limited by the knock limit, an additional quantity of main fuel is injected in a third stage during the power stroke.