Abstract: A control system for an internal combustion engine, which is capable of properly setting fuel injection timing according to the actual degree of delay of the amount of fresh air to be supplied to cylinders of the engine, thereby making it possible to positively suppress torque variation, when the control system has switched an air-fuel ratio mode between a lean mode and a rich mode. The control system controls the air-fuel ratio of a mixture by switching the air-fuel ratio mode. In the lean mode, the control system sets a target fresh air amount for the lean mode, and in the rich mode, it sets a target fresh air amount for the rich mode. Upon switching the air-fuel ratio mode, the control system corrects the fuel injection timing according to the difference between the target fresh air amount for the lean mode or the rich mode and the detected fresh air amount.

Abstract: The present invention provides a fuel control for an internal-combustion engine having an exhaust gas purifying device that is disposed in an exhaust system of the engine. A reducing agent is supplied to the exhaust gas purifying device by injecting fuel in an expansion stroke or an exhaust stroke of the engine. An intake air amount supplied to the engine is controllable. The fuel control includes decreasing the intake air amount supplied to the engine during the fuel injection for the supply of the reducing agent. The fuel control also includes advancing an injection timing of the fuel injection for the supply of the reducing agent when an actual intake air amount is less than a desired intake air amount or when an actual boost pressure is higher than a desired boost pressure. The advancement of the injection timing improves the combustibility of engine while decreasing the HC exhaust amount.

Abstract: In a plastic retainer for roller bearing comprising first and second annular members disposed in axially spaced apart relationship, a plurality of posts containing the annular members and disposed circumferentially equidistantly, and a pocket for containing a roller formed between two adjacent posts and the annular members, the side surface of the post forming the pocket which is adjacent to the first annular member has a planar portion, the connecting portion between the planar portion and the first annular member provides a curved surface concave toward the pocket, and the radius of curvature of the curved surface is minimum on the pitch circle of the roller and is greater toward at least one side of the radial direction of the retainer.