The United States of America As Represented by the Administrator of the

The United States of America As Represented by the Administrator of the U.S. Environmental Protection Agency

Other

Karl H Hellman

Charles L Gray, Jr

Ruonan Sun

Michael J Safoutin

Ronald M Schaefer

An internal combustion engine is adapted for operation with homogeneous combustion and compression ignition. The engine includes plural cylinders with the piston in each cylinder defining the main combustion chamber and connected to a crankshaft for reciprocating motion rotatably driving the crankshaft. An auxiliary combustion chamber and an inlet passage are formed in the engine head for each of the cylinders with a control valve for controlling communication between the main combustion chamber and the auxiliary combustion chamber and an inlet valve for controlling communication between the main combustion chamber and the inlet passage. The inlet valve is driven with rotation of the crankshaft, while the drive for the combustion control valve is independent of angular position of the crankshaft and has its own controller for timing its opening and closing to provide controlled homogeneous combustion.

HCCI engine with combustion-tailoring chamber

A coolant system and method for control of cylinder temperature in a multiple cylinder internal combustion engine includes an inlet rail for receiving coolant from a pump, an outlet rail located on a side of the cylinder head opposite the inlet rail and a plurality of individual coolant flow passages extending within the cylinder head and connecting the inlet rail with the outlet rail. A control valve and an associated temperature sensor are provided within each of the coolant flow passages and a controller individually controls each of the control valves in accordance with a signal received from its associated temperature sensor. The control valves may be controlled to bring the temperatures detected by their associated temperature sensors into conformance with an optimum temperature predetermined for engine speed and/or engine torque load.

Individual cylinder coolant control system and method

An exhaust gas recirculation system for an internal combustion engine includes an exhaust manifold and at least one exhaust flow control valve located between the engine and the exhaust manifold. The exhaust flow control valve diverts a portion of the exhaust gas from each cycle of one cylinder and feeds that diverted portion to another of the cylinders through an exhaust gas recirculation passage, bypassing the exhaust manifold, whereby an exhaust stroke of a piston within the one cylinder serves to pump exhaust gas through the exhaust flow control valve in another cylinder.

Pumped EGR system

The invention is a combustion method for operation of a multiple cylinder internal combustion engine in a cycle including intake, compression, expansion and exhaust strokes. A first amount of fuel is introduced into each of the cylinders with introduction initiated earlier than 45.degree. before top dead center of a combustion stroke. An amount of air significantly in excess of that providing a stoichiometric amount of oxygen, typically 2-3 times stoichiometry, is also introduced into each of the cylinders to produce a first mixture upon introduction of the fuel, which mixture is ignited to produce a first combustion event. Subsequent to substantial completion of the first combustion event but prior to top dead center in the same compression stroke (or shortly after top dead center in the expansion stroke), a second amount of fuel is introduced into each of the cylinders without introduction of additional air. The second amount of fuel, products of combustion from the first combustion event and oxygen-depleted air form a second mixture which is ignited to produce a second combustion event. Utilizing two (or more) distinct combustion events in each 'combustion cycle' significantly reduces the formation of NO.sub.x.

Multi-stage combustion engine

A hydropneumatic powertrain includes a fluidic driver connected in parallel with first and second liquid tanks connected, respectively, with first and second gas vessels. The gas within each gas vessel is in fluid communication with the liquid within the corresponding liquid vessel. A prime mover drives a pump to pump liquid alternately into one of the two liquid tanks connected in parallel with the pump. Switch valving directs the discharge of the pump to either the first liquid tank or the second liquid tank, while the liquid tank not receiving liquid from the pump discharge is discharging its liquid, driven by expansion of gas within the corresponding gas vessel, to drive the fluidic driver which, in turn, drives the drive wheels of the vehicle. Each gas tank is equipped with a heater and a cooler whereby the gas vessel, in the compression portion of the cycle, is cooled while the other gas vessel is heated for expansion of the gas contained therein. Thus, the fluidic driver can be continuously driven by alternating discharges from the two liquid tanks.

Accumulator engine

A method of operation of an internal combustion engine to minimize NOx emission in exhaust gas involves detection of load on the vehicle engine as either a low load or a high load. While a low load is detected unthrottled air and a quantity of fuel providing for lean combustion are mixed with injection of fuel adjacent top dead center in the compression stroke. While a high load condition is detected, throttled air and a quantity of fuel governed by sensed oxygen content of the exhaust gas are mixed in an approximate stoichiometric ratio with injection of the fuel much earlier than injection at low load, preferably during the intake stroke.

Combined cycle engine

A vehicular powertrain with regenerative braking includes a plurality of wheels and a brake pedal which, upon engagement, is activated first into a first zone of operation and then into a second zone of operation. A braking detector detects either a released state or an engaged state for the brake pedal and, if in the engaged state, detects if the pedal is in the first or the second zone of operation. Friction brakes brake a pair of the wheels, responsive to detection of the brake pedal within the second zone of operation. The hydraulic portion of the drivetrain includes an accumulator for storing hydraulic fluid under pressure and a reservoir for storing the hydraulic fluid at a lower pressure. A pump/motor is located in the high pressure line for operation as a motor to drive the drive wheels in a drive mode and for operation as a pump driven by the drive wheels in a braking mode. A prime mover has its inlet connected to the reservoir through a low pressure line and an outlet connected to the accumulator through a high pressure line and hydraulically drives said pump/motor in its motor mode. A controller switches the pump/motor into the braking mode responsive to detection of an engaged state for the brake pedal and into the drive mode responsive to detection of the released state of the brake pedal. A switch valve connects the high pressure line to the accumulator in the braking mode and to the reservoir in the drive mode.

Anti-lock regenerative braking system

Engine output speed is controlled for optimum efficiency by adjustment of input speed of a continuously variable transmission (CVT). Where power in excess of that provided by the engine is required, additional power is input to the drivetrain from a fluidic motor driven by fluid pressure stored in an accumulator. In driving conditions where the engine, operating at optimum efficiency, produces power in excess of that demanded by of the vehicle, the fluidic motor is reversed for operation as a pump and excess engine power is utilized to drive the pump and store energy in the accumulator in the form of fluid pressure. A CPU determines power output required of the engine as a sum of that indicated by a sensor which senses power demanded of the vehicle by a driver and an increment of power required to maintain the pressure of the accumulator above a threshold amount. An engine speed controller controls the rotary speed of the engine output, to produce the required total power output, by changing the input speed of the CVT. In order to maintain optimum engine efficiency, a memory associated with the CPU is stored with maps correlating values for optimum engine speed with values for engine output power and the optimum engine speed is read from the map by reference to the determined total requirement for engine output power. Optionally, the vehicle may include first and second engines with the second engine providing a power assist under driving conditions demanding power in excess of that available from the primary engine in combination with the fluidic motor. The invention also includes a method of operating the system in order to achieve the objective of optimum engine efficiency.

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Ann Arbor, MI, United States of America

Karl H Hellman