Patent ID: 7543668
Filing Date: 2009-06-09
Classification: B60K,F02D,F02N,Y02T

Abstract:
1. A method of operating a vehicle, said method comprising the steps of: (a) providing an engine mounted in said vehicle for its propulsion and braking, said engine including at least two cylinders and a cylinder chamber within each of said at least two cylinders, (b) providing a control means for controlling the operation of said engine and said vehicle in response to driver's demands and in accordance with a control program incorporated in said control means, (c) providing an air-reservoir means mounted in said vehicle and connected to said engine for receiving, storage, and discharge of compressed air, (d) providing a gas exchange controlling means for accommodating and controlling gas flow into, inside, and out of said engine and between said engine and said air-reservoir means, (e) providing a switching means for setting an arrangement of said gas exchange controlling means into a configuration selected from a variety of configurations, and switching said arrangement from one configuration to another in accordance with said program incorporated in said control means, (f) operating said engine in a compression-braking mode driven by a vehicle momentum in response to a demand for a vehicle braking force by repeatedly performing a two-stage compression of air in said engine, said two-stage compression of air comprising the steps of: (g) using said energy of compressed air stored in said air-reservoir means for said vehicle acceleration and propulsion in response to a demand for a vehicle propulsion force by operating said engine in an air-assisted mode, said air-assisted mode including operating said engine in a mode selected from a variety of propulsion modes comprising: (h) operating said engine in an internal-combustion mode that includes using chemical energy of fuel burned inside said cylinder chamber for said vehicle acceleration and propulsion without using said energy of compressed air stored in said air-reservoir means when said control program does not demand operation in said air-assisted mode, and when said energy of compressed air is not available, and (i) using said control means to control the mode of said engine operation and to control the magnitude of said vehicle braking force and of said vehicle propulsion force, whereby combined effect of converting energy of vehicle motion into energy of compressed air during said vehicle braking, and using said energy of compressed air for said vehicle acceleration and propulsion at a later time reduces said vehicle fuel consumption, and whereby using two-stage air compression and two-stage air expansion reduces the required size of said air-reservoir means.