Showing papers on "Four-stroke engine published in 1996"

Internal combustion engines with combined cam and electro-hydraulic engine valve control

Abstract: An internal combustion engine has electrically controlled hydraulic linkages (64) between engine cams (40) and engine cylinder valves (30) If it is desired to skip a cam lobe (42a, 42b, 42c) or to modify the response of an engine cylinder valve to a cam lobe (42a, 42b, 42c), hydraulic fluid is selectively released from the associated hydraulic linkage (64) to permit lost motion between the cam (40) and the engine cylinder valve (30) Electrically controlled hydraulic fluid valves (100) are used to produce the selective release of hydraulic fluid from the hydraulic linkages (64) The mode of operation of the engine can be changed (eg, from positive power mode to compression release engine braking mode or vice versa), or more subtle changes can be made to modify the timing and/or extent of engine cylinder valve openings to optimize engine performance for various engine or vehicle operating conditions (eg, different engine or vehicle speeds)

A Study of Combustion of Hydrogen-Enriched Gasoline in a Spark Ignition Engine

Abstract: An investigation has been done on the influence of small amounts of hydrogen added to hydrocarbons-air mixtures on combustion characteristics. The effect of hydrogen addition to a hydrocarbon-air mixture was firstly approached in an experimental bomb, to measure the laminar burning velocity and the shift of lean flammability limit. Experiments carried out with a single-cylinder four stroke SI engine confirmed the possibility of expanding the combustion stability limit, which correlates well with the general trend of enhancing the rate of combustion. An increase of brake thermal efficiency has been obtained with a reduction of HC emissions; the NO{sub x} emissions were higher, except for very lean mixtures.

Overhead cam engine with dry sump lubrication system

Abstract: A single cylinder, internal combustion engine with a dry sump lubrication system. The engine includes an engine housing in which the overhead camshaft and crankshaft are rotatably supported, and the housing includes an integrally formed cylinder and head. A timing belt disposed externally of the engine housing interconnects the crankshaft and camshaft, and a piston connected to the crankshaft reciprocates within an internal bore provided in the engine housing cylinder. The cylinder wall around the internal bore is of a generally uniform thickness and circumscribed by cooling fins such that the cylinder resists bore distortion during operation. Dry sump lubrication is obtained by an external oil reservoir connected to a pump which supplies pressurized oil to the bearing journals of the camshaft. A portion of the oil at the camshaft bearing journals flows through passages provided within the cylinder to lubricate the bearing journals of the crankshaft. The reciprocating motion of the valve assemblies controlling intake and exhaust of the combustion chamber pumps the oil which lubricated the camshaft back to the external reservoir. The reciprocating motion of the piston similarly effects a high pressure within the crankcase cavity to pump oil which has lubricated the crankshaft back to the external reservoir. The inventive engine further provides for the mounting of flywheels within the crankcase cavity in conjunction with an external, lightweight fan for engine housing cooling, as well as employs a cast in valve seat for the overhead valve assemblies.

Arrangement controlling the output pressure of a turbocharger for an internal combustion engine

Abstract: A control arrangement for a turbocharger for an internal combustion engine with a variable turbine geometry which includes a control unit for controlling a turbocharger output pressure according to engine operating parameters when the engine is operating in a first engine load range with regulated exhaust gas return and a pressure controller for controlling the turbocharger output pressure when the engine is operating in a second engine load range with the exhaust gas return switched off including allowance for a precontrol by the control unit.

The Combustion Process in a DI Diesel Hydraulic Free Piston Engine

Abstract: In a free piston engine the piston is neither connected to a crankshaft mechanism nor to any other kinematic system. Instead the piston movement is determined by the free forces that act upon it. This difference between the kinematic principle of the crankshaft engine and the free piston principle has a significant influence on the combustion process. In this paper the combustion process in a free piston engine is described on the basis of experiments. The experimental data were obtained from measurements on the free piston engine that has been developed by the Dutch company Innas. This article discusses the influence of the free piston principle on cold start, ignition delay, heat release, heat transfer, indicated efficiency and emissions. In the optimum point the engine has an indicated efficiency of 51%, a NOx emission of 6 gr/kWhi and a soot emission corresponding to a Bosch Filter Number of less than 0.5. The combustion process of the free piston engine is furthermore characterized by a nearly constant volume combustion process.

Turbocharged engine system with recirculation and supplemental air supply

Abstract: A turbocharged engine air supply system for eliminating turbo lag in an internal combustion engine includes an air tank containing a pressurized auxiliary air supply which is used to raise manifold pressure promptly during periods of turbo lag, an air pump connected with the engine crankshaft for filling the air tank with compressed air during deceleration and during other periods of operation when it is not necessary to devote all of the engine torque to the driveline, a first valve for controlling the flow of auxiliary air from the air tank to the engine, and a second valve for recirculating turbocharged air when auxiliary air is being supplied to the engine, thereby allowing the turbocharger to accelerate more quickly.

PIFFO - Piston Friction Force Measurements During Engine Operation

Abstract: Fuel consumption of a modern combustion engine is significantly influenced by the mechanical friction losses Particularly in typical city driving, the reduction of the engine friction losses offers a remarkable potential in emission and fuel consumption reduction The analysis of the engine friction distribution of modern engines shows that the piston group has a high share at total engine friction This offers a high potential to optimize piston group friction The paper presents results of recent research and development work in the field of the tribological system piston/piston ring/cylinder bore

Combustion chamber and induction system for engine

Abstract: An internal combustion engine having a direct cylinder injection and including a variable valve timing mechanism for at least changing the time of closing of the intake valve. The fuel injection timing and intake valve closing timing are controlled so that under low and mid-range engine speeds, but high loads, the intake valve is closed before the piston reaches bottom dead center position on its intake stroke so as to reduce the effective compression ratio. Fuel injection timing is begun before the piston has reached its bottom dead center position during the intake stroke under high-speed, high-load conditions and is not initiated until after the piston has reached its bottom dead center position and begun its compression stroke under other engine running conditions. The engine is provided with an injector location and piston with a bowl in its head that improves fuel stratification under at least some running conditions so as to permit lean burn operation. The intake valves are offset to one side of a plane containing the axis of the cylinder bore, and the fuel injector is disposed between a pair of intake ports and below them so as to direct its injection axis toward the exhaust side and toward the recess in the head of the piston.

Valve timing for four stroke internal combustion engines

Abstract: A method of controlling a four stroke internal combustion engine having at least one combustion chamber, the or each combustion chamber having at least one exhaust valve, the method including varying the timing of the closure of the or each exhaust valve with respect to the crank angle of the engine by advancing the exhaust valve closure at least under certain engine conditions in response to an increased engine load, and/or delaying the exhaust valve closure at least under certain conditions in response to a decreased engine load.

Lubrication and crankcase ventilating system for four-cycle outboard motor

Abstract: An outboard motor having a high-performance V-type twin overhead cam four-cycle internal combustion engine. The oil reservoir for the engine is disposed in a driveshaft housing below the engine and an oil pump is driven off the lower end of the engine crankshaft for circulating the oil from the oil tank to the engine. The oil supply system for the engine includes a vertically extending main gallery and a drain passage which extend in parallel side-by-side relationship and which are disposed over the oil tank for ease of oil return. The exhaust and cooling system for the engine is configured so as to minimize heat transfer between the exhaust system and the lubricating system and to maintain a compact assembly. The engine has an improved oil reservoir and crankcase ventilating system.

Direct cylinder injected engine and method of operating same

Abstract: An internal combustion engine having a direct cylinder injection and including a variable valve timing mechanism for at least changing the time of closing of the intake valve. The fuel injection timing and intake valve closing timing are controlled so that under low and mid-range engine speeds, but high loads, the intake valve is closed before the piston reaches bottom dead center position on its intake stroke so as to reduce the effective compression ratio. Fuel injection timing is begun before the piston has reached its bottom dead center position during the intake stroke under high-speed, high-load conditions and is not initiated until after the piston has reached its bottom dead center position and begun its compression stroke under other engine running conditions. The engine is provided with an injector location and piston with a bowl in its head that improves fuel stratification under at least some running conditions so as to permit lean burn operation. The intake valves are offset to one side of a plane containing the axis of the cylinder bore, and the fuel injector is disposed between a pair of intake ports and below them so as to direct its injection axis toward the exhaust side and toward the recess in the head of the piston.

Piston unit for an internal combustion engine

Abstract: Piston unit for an internal combustion engine, especially for a large diesel engine, comprising at least three main parts located in successive order in the direction of the longitudinal axis of the piston and to be connected to each other. The piston unit includes a uniform upper part (3), which defines, when installed within a cylinder of the engine, a combustion chamber from the side of the piston and which is fixed inside of the piston at its central region to a middle part (2) of the piston unit preferably by means of a screw (4) or the like. At least the main part of, preferably all of the piston ring grooves (7) are arranged on a middle part (2). In addition the upper part (1) is selected to be of a material with better heat resistance than that of the middle part (2) and of a lower part (1).

Oil pan arrangement for four-cycle outboard motor

Abstract: An outboard motor having a high-performance V-type twin overhead cam four-cycle internal combustion engine. The oil reservoir for the engine is disposed in a driveshaft housing below the engine and an oil pump is driven off the lower end of the engine crankshaft for circulating the oil from the oil tank to the engine. The oil supply system for the engine includes a vertically extending main gallery and a drain passage which extend in parallel side-by-side relationship and which are disposed over the oil tank for ease of oil return. The exhaust and cooling system for the engine is configured so as to minimize heat transfer between the exhaust system and the lubricating system and to maintain a compact assembly.

Four cycle outboard motor

Abstract: An outboard motor having a high-performance V-type twin overhead cam four-cycle internal combustion engine. The oil reservoir for the engine is disposed in a driveshaft housing below the engine and an oil pump is driven off the lower end of the engine crankshaft for circulating the oil from the oil tank to the engine. The oil supply system for the engine includes a vertically extending main gallery and a drain passage which extend in parallel side-by-side relationship and which are disposed over the oil tank for ease of oil return. The exhaust and cooling system for the engine is configured so as to minimize heat transfer between the exhaust system and the lubricating system and to maintain a compact assembly.

Piston combustion engine having a system for recirculating exhaust gases and system for use in such an engine

Abstract: In order to reduce the emission of harmful substances, in particular NOx, a system of exhaust gas recirculation (EGR) is used in piston combustion engines. A positive pressure difference between the exhaust and inlet volumes is needed in order to displace the exhaust gas. The invention provides a piston combustion engine including an EGR turbine (17) connected to a first portion of the exhaust manifold (5) and an EGR compressor (21) connected to a second portion of the exhaust manifold (5). As a result of this a balanced gas exchange in the exhaust portions of the engine is obtained.

Adiabatic, two-stroke cycle engine having external piston rod alignment

Abstract: An engine structure and mechanism that operates on various combustion processes in a two-stroke-cycle without supplemental cooling or lubrication comprises an axial assembly of cylindrical modules and twin, double-harmonic cams that operate with opposed pistons in each cylinder through fully captured rolling contact bearings. The opposed pistons are double-acting, performing a two-stroke engine power cycle on facing ends and induction and scavenge air compression on their outside ends, all within the same cylinder bore. The engine includes a novel intake/exhaust valve configuration, a novel combustion chamber configuration and a novel external piston rod alignment structure comprising a cam follower assembly including a pair of needle roller bearings riding in longitudinal grooves machined in the cam follower body.

Method for identifying the cylinder phase of an internal combustion multi-cylinder four stroke engine

Abstract: Method for identifying cylinder phase in an engine with an ignition and/or injection system wherein each cylinder is individually controlled, and with a sensor cooperating with a rotary target having an indexing element indicating a reference cylinder upper dead center position The method including the steps of generating, on the reference cylinder, a disturbance other than the interruption of the injection, the disturbance of a type capable of causing a change in the engine torque, detecting the engine torque change by a change in a signal representative of the gas torque, caused by the generation of the disturbance, establishing a relationship between the time of generation and the detection of its result on the engine torque so as to derive the reference cylinder phase at the time of generation of the disturbance, and thereafter the phase of the other cylinders The method of the present invention being particularly useful for four stroke engines with sequential ignition and/or injection

Method of identifying the stroke positions in an internal combustion engine upon startup

Abstract: In a method of identifying stroke positions and for synchronizing sequential fuel or ignition distribution to cylinders of a four-stroke internal combustion engine with an even number of cylinders, as a function of signals of a crankshaft sensor, pistons of two cylinders each having the same position and direction of motion always form one group. Fuel injection and ignition is jointly carried out for each group from engine starting until a predetermined engine operating state is reached. Either fuel injection or ignition of a predetermined cylinder is omitted for at least one engine stroke, once the predetermined engine operating state is reached. If combustion does not occur within two engine cycles, beginning with the engine stroke in which the fuel injection or the ignition is omitted for the first time, the predetermined cylinder and otherwise the other cylinder of the same group is synchronized. A switch over to sequential fuel injection or ignition is carried out once synchronization has been carried out.

Internal combustion engine with crankcase pressure barrier

Abstract: An internal combustion engine includes a cylinder (10), a crankcase (30), a crankshaft rotatable in the crankcase, a piston, and a connecting rod supporting the piston for reciprocating movement in the cylinder (10) and mounted on the crankshaft. A barrier member extends around the connecting rod (13) to sealingly separate the cylinder (10) from the crankcase (30). The barrier member (20) is laterally displaceable to provide for angular motion of the connecting rod (13) as the piston (12) reciprocates in the cylinder (10).

Method and apparatus for multiple cycle internal combustion engine operation

Abstract: A method for operating a reciprocating piston-type internal combustion engine selectively in two-stroke, four-stroke, and six-stroke mode includes: providing transfer valves, transfer passage means between piston cylinders, selectively controlling the actuation and timing of the intake, exhaust and transfer valves, and alternatively operating the intake and exhaust valves for each piston cylinder in overlapping sequence during each crankshaft revolution to provide two-stroke operation, operating the intake and exhaust valves in sequence during each second crankshaft revolution to provide four-stroke operation, operating the intake, exhaust, and transfer valves sequentially to cause a secondary expansion stroke in an adjacent piston cylinder to provide six-stroke operation of the engine.

System for powering rotating accessories of an internal combustion engine

Abstract: A system for powering various rotating vehicle accessories such as an alternator, a power steering pump, and an air-conditioning compressor from both a water pump and an engine's crankshaft. At relatively low engine crankshaft speeds, the accessories are driven by a clutch mounted on a water pump at a first speed ratio relative to the engine crankshaft speed; at relatively high engine crankshaft speeds, the accessories are driven by the crankshaft at a second speed ratio relative to the engine crankshaft speed.

Internal combustion engine with eight stroke operating cycle

Abstract: An inventive internal combustion engine adapted for an eight piston stroke operating cycle. The rate of comsumption of fuel and air mixture, and the pressure at which it is ignited and combusted, is enhanced by the addition of a holding chamber for fuel and air mixture which retains an initial intake charge of mixture to be later mixed with a subsequent intake charge before compression and combustion within the cylinder. The engine is therefore capable of greater power with given size cylinders. Conversely, the engine is capable of producing a target rate of fuel consumption and power output with smaller cylinders. The engine may also be designed to operate in a Diesel manner utilizing an appropriate hydrocarbon fuel.

Braking a four stroke IC engine

Abstract: In a method for braking a four-stroke internal combustion engine having cylinders each having a combustion chamber and at least one outlet valve connected to an outlet system and controlled by an engine camshaft, wherein the outlet system comprises a choke device, the flow of exhaust gas in the outlet system is choked with the choke device such that the exhaust gas upstream of the choke device is subjected to a pressure increase. The outlet valve is opened intermediately with the pressure increase in the exhaust gas such that the exhaust gas flows back into the combustion chamber. The outlet valve is positively maintained in a part-open position with a control device, operating independently of the engine camshaft and incorporated into an outlet valve actuating mechanism, during a subsequent compression stroke of the engine for a period of time ending at the latest when the engine camshaft acts on the outlet valve in order to fully open the outlet valve.

Air/fuel control system with lost fuel compensation

Abstract: An air/fuel control method for an internal combustion engine. A portion of fuel delivered to the engine which is lost between the piston and engine cylinder walls during predetermined engine operating conditions is calculated. Fuel delivered to the engine is then adjusted for the calculated lost fuel quantity to achieve a desired engine air/fuel ratio.

Method for improving spark ignited internal combustion engine starting and idling using poor driveability fuels

Abstract: A method for maintaining the rotational speed of a crankshaft of an internal combustion engine having a plurality of cylinders each having a spark plug wherein a predetermined amount of delivered fuel is to be combusted at a firing time within each of the plurality of cylinders with each rotation of the camshaft or crankshaft includes the step of operating the internal combustion engine, measuring the rotational speed of the crankshaft, defining an expected engine speed, calculating a speed error as the rotational speed of the crankshaft less the expected engine speed, and changing the predetermined amount of delivered fuel to be combusted in each of the plurality of cylinders to reduce the speed error. The preferred embodiment is implemented in fuzzy logic.

Method for detecting combustion misfires

Abstract: The invention is directed to a method for detecting misfires in the combustion of a z-cylinder four stroke internal combustion engine wherein the engine includes a transducer wheel coupled to the crankshaft of the engine and rotating in phase synchronism with the crankshaft. The transducer wheel has typically z/2 segments and the segments are scanned with a sensor device to supply a segment-time signal reflecting the nonuniformity of the rotational movement of the crankshaft with respect to individual ones of the cylinders of the engine. Rough-running values are formed for each cylinder on the basis of the segment times with each of the rough-running values including a component occurring at the frequency of the crankshaft. The component is filtered out and then the filtered rough-running value is compared to a threshold value. A misfire is determined to be present when the filtered rough-running value exceeds the threshold value.

Four-stroke internal combustion engine

Abstract: A four-stroke internal combustion engine with a gabled combustion chamber d at least two intake valves and at least two intake conduits per cylinder, of which a first intake conduit is embodied as unthrottled and a second intake conduit has a throttle device. To attain a stable radial mixture layering, it is provided that the fuel injection valve is disposed in the second intake conduit, and the throttle device in the closed state produces a defined minimum flow rate of between about 5% and about 20%, preferably about 10%, of the maximum flow rate, and that viewed in the direction of the crankshaft axis the center line of the first intake conduit in the intake valve region has a greater radius of curvature than does the center line of the second intake conduit.

Orbiting piston combustion engine

Abstract: An orbiting piston combustion engine (10) includes an orbital cylindrical block (12) with a continuous orbital cylinder (90) within the block. Within the cylinder is a continuously orbiting piston assembly (100) which includes a compression piston (118) with a compression chamber (134) therebehind and a power piston (102) with a combustion chamber (136) therebehind. A power transfer mechanism (24) is engageable with the continuously orbiting piston assembly for power transfer from the engine.

Internal combustion engine with an exhaust gas turbocharger

Abstract: In an internal combustion engine with an exhaust gas turbocharger which supplies compressed charge air to the engine via a charge air duct including an intercooler with a housing and a cooling structure for cooling the compressed charge air before it is supplied to the engine, the intercooler housing has an inlet area connected to the turbocharger by an upstream section of the charge air duct and an outlet area connected to the engine by a downstream section of the charge air duct and an air flow control mechanism which is arranged between the inlet and outlet areas and operable to be open during engine warm-up when the engine is below a predetermined temperature so that the charge air by-passes the cooling structure during engine warm-up.

Four-cam outboard motor

Abstract: A high-performance outboard motor embodying a V-type four overhead camshaft four-cycle internal combustion engine. A compact cam driving arrangement is provided for driving the camshafts from the crankshaft of the engine at the upper end. A flywheel is mounted to the lower end of the crankshaft and is driven by a starter motor for starting of the engine. Another engine accessory is driven off the upper end of the crankshaft so as to maintain a compact and yet highly serviceable arrangement.