Turbocharged engine and method for controlling same

Abstract

The invention provides a turbocharged engine and a method for controlling the same. A system and method for controlling a multiple cylinder internal combustion engine having an exhaust gas turbocharger with a compressor coupled to a turbine include redirecting substantially all intake airflow around the compressor and substantially all exhaust flow around the turbine when an engine operating parameter exceeds an associated threshold. In one embodiment, turbocharger boost is provided below an associated engine speed threshold with the turbocharger compressor and turbine bypassed at higher engine speeds such that the engine operates as a naturally aspirated engine.

Description

technical field [0001] The invention relates to an internal combustion engine with an exhaust gas turbocharger. Background technique [0002] An exhaust turbocharger includes an exhaust turbine that drives a compressor to boost the intake air pressure above atmospheric pressure, thereby increasing the power output from the engine. Conventional turbocharged engines use a turbocharger for boosting throughout the engine's operating speed range. This can lead to narrow turbocharger selection and / or low engine performance, as small, fast-responding turbochargers are expected for low-speed engine boost and quick response, while larger, less restrictive turbochargers are desired. Turbochargers are used to increase power at higher engine speeds. The size of the turbocharger and other engine components for operation over the entire engine operating range (especially for high speed / high load operation) can lead to an increase in cost associated with additional engine structure, weig...

AI Technical Summary

Problems solved by technology

This can lead to narrow turbocharger selection and / or low engine performance, as small, fast-responding turbochargers are expected for low-speed engine boost and quick response, while larger, less restrictive turbochargers are desired. Turbochargers are used to increase power at higher engine speeds

The size of the turbocharger and other engine components for operation over the entire engine operating range (especially for high speed / high load operation) can lead to an increase in cost associated with additional engine structure, weight increase and compliance associated Materials that operate at higher peak pressures and higher temperatures are more expensive

Additionally, increased engine friction losses and weight may be associated with a more robust engine structure

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