Variable cylinder engine

摘要

A variable cylinder engine is provided. The engine includes an engine body having a plurality of cylinders, a cooling mechanism for cooling the engine body by using a coolant, and a controller for controlling a temperature of the coolant and changing the number of active cylinders according to an operating state of the engine. The controller reduces the number of active cylinders in a reduced-cylinder operating range set within a partial engine load range, and expands the reduced-cylinder operating range to a higher engine load side as the coolant temperature becomes lower.

主权项

1. A variable cylinder engine, comprising:
an engine body having a plurality of cylinders; a cooling mechanism for cooling the engine body by using a coolant which flows through the engine body, wherein the cooling mechanism includes a coolant path and a radiator; a switch valve able to regulate a flow of the coolant through the coolant path; a coolant temperature sensor which detects a coolant temperature; a valve stopping mechanism configured to selectively reduce cylinder operation of the engine to a reduced number of cylinders when an operating point of the engine is in a reduced-cylinder operating range; and a controller configured to:
calculate a first operating point that defines where the engine can reduce cylinder operation via the valve stopping mechanism when below and increase cylinder operation via the valve stopping mechanism when above, but when the temperature of the coolant detected by the temperature sensor decreases further during reduced cylinder operation recalculate to create a second operating point to be a higher value than the first operating point so that reduced cylinder operation continues when above the first operation point but below the second operating point.