Showing papers on "Four-stroke engine published in 1987"

Automotive Engine Modeling for Real Time Control Application

Abstract: A nonlinear port fuel injected automotive engine model is developed which can be used for the design of engine control algorithms, or within an algorithm for real time control. The model is being validated using a sequential fuel injection V-6 engine, and includes: ? intake manifold dynamics, ? fuel dynamics, and ? process delays inherent in the four stroke engine cycle. The model is compact enough to run in real time and can be used as an embedded model withim a control algorithm or an observer. Although developed for a specific engine, the model can be adapted to represent various types of automotive engines with a limited amount of engine data. Preliminary validation results look very promising.

Turbo compound engine

Abstract: A turbo compound engine including driving force transmitting means for connecting the crankshaft of an engine, and a power turbine disposed in an engine exhaust passage achieves adequate engine brake force by applying a resistance force against the crankshaft directly or indirectly during the exhaust brake because the engine brake force of the turbocharged engine suffers a relative decrease due to the increase in the output power.

Turbulence intensity and spatial integral scale during compression and expansion strokes in a four-cycle reciprocating engine

Abstract: A laser homodyne technique is applied to measure turbulence intensities and spatial scales during compression and expansion strokes in a non-fired engine. By using this technique, relative fluid motion in a turbulent flow is detected directly without cyclic variation biases caused by fluctuation in the main flow. Experiments are performed at different engine speeds, compression ratios, and induction swirl ratios. In no-swirl cases the turbulence field near the compression end is almost uniform, whereas in swirled cases both the turbulence intensity and the scale near the cylinder axis are higher than those in the periphery. In addition, based on the measured results, the k-epsilon two-equation turbulence model under the influence of compression is discussed.

Internal combustion engine and devices employing same

Abstract: An engine and power units employing the engine are provided which include a crankshaft oriented vertically and operatively connected to the engine, a liquid-cooled radiator arranged above the engine substantially perpendicular to the crankshaft, and a cooling fan interposed between the engine and the radiator and operatively connected to the crankshaft. The engines and power units may be employed in motor vehicles and other equipment such as electrical generators.

Valve operating mechanism for internal combustion engines

Abstract: A valve operating mechanism for an internal combustion engine having cams rotatable in synchronism with a crankshaft, a pair of valves disposed in intake or exhaust ports of a combustion chamber, and four pivotable rocker arms for transmitting the lifting motion of said cams to said valves. Four cams are provided with different cam profiles corresponding to respective ranges of rotational speeds of the engine. Switching means are operated by hydraulic oil pressure for selectively connecting and disconnecting the rocker arms to thereby operate the valves in several different modes for different engine speeds.

Multicylinder internal combustion engine utilizing split block with unitized cylinder head and liner

Abstract: Multicylinder internal combustion engine of the type having a crankshaft and a block comprised of first and second mating half sections joined in a common plane which passes through and along the axis of the crankshaft. The half sections provides a crankcase crankshaft bearing support and cylinder portions. A unitized cylinder head and sleeve construction is provided. A cooperative securing mechanism is provided for securing the unitized cylinder head and sleeve construction to the engine block.

Energy producing installation with internal combustion engine and turbine

Abstract: The installation comprises a compression unit and a power unit. The compression unit comprises at least one engine operation according to a Diesel cycle and supercharged by a turbine having an expansion turbine supplied with the exhaust gases of the engine and rotary compressor taking air from the atmosphere through a filter. The compressor delivers a primary supercharging flow to the Diesel cylinders via a cooler. The Diesel engine drives two compressors supplied with atmospheric air through the filter. One of the compressors provides a secondary flow to the power unit. The power unit comprises a combustion chamber which is supplied through the exchanger with part at least of the secondary airflow from the compression unit. The combustion chamber feeds a turbine producing on its shaft the whole of the output power. The Diesel type engine may be a conventional crank type engine or a free piston engine.

Four-stroke internal-combustion engine and procedure for operating such an engine

Abstract: A four-stroke cycle internal combustion engine including a scavenging air system to minimize the emission of oxides of nitrogen. The engine includes a scavenging valve to admit scavenging air into the cylinder, and the scavenging valve is so oriented as to cause scavenging air to flow radially toward the center of the cylinder. The inlet valve and valve seat are configured in such a way as to cause the air-fuel mixture to circulate circumferentially within the cylinder and a spark plug is provided to ignite the air-fuel mixture. Additionally, an air charging system is provided to pressurize the air that is introduced for scavenging purposes, and a portion of the air from the air charging system is conveyed to an air cooling system, within which the fuel is added to the air, whereupon the air-fuel mixture is cooled to a temperaturea below the temperature of the scavenging air.

Operational Characteristics of a Lean Burn Sl-Engine: Comparison Between Plasma-Jet and Conventional Ignition System

Abstract: Besides the specific demands on mixture formation the main problem of lean-mixture SI engines is to assure the ignition of the air-fuel mixture even if very lean and at all operational conditions. In the scope of extensive research work an analysis was made of the operational behavior of a 4-stroke SI-engine with a newly developed plasma-jet ignition and a conventional transistorized ignition system, respectively. The investigations on the engine were completed by tests in a combustion chamber with methane-air mixture. With plasma-jet ignition the combustion delay and the combustion duration are clearly shorter. The engine tests also revealed a clearly extended lean misfire limit and a reduction of cyclic variations. The NO/sub x/-emissions are only slightly higher than with the transistorized ignition system although a considerable improvement of the brake efficiency can be obtained.

Method for manufacturing piston of internal combustion engine

Abstract: A method for manufacturing a piston of an internal combustion engine, especially for forming a piston gallery portion provided in the piston head for cooling the engine. A gallery member made of a metal pipe having a high thermal conductivity or a salt-core having a shape corresponding to the piston gallery is fixed to a fixing member having a peripheral rim and a plurality of fixing legs extended from the rim. The gallery member or the salt-core fixed to the fixing member is cast in the piston, body, and then, the fixing member is cut off from the piston body. The salt-core is melted away by pouring water. By this method, a piston of light weight and having high cooling efficiency can be manufactured.

Piston system for use in an internal combustion engine

Abstract: A piston system for use in an internal combustion engine comprises a flexible piston disposed adjacent a combustion chamber of the engine and a piston drive means movably disposed adjacent the flexible piston such that the drive means can deform the flexible piston of the engine and combustion in the combustion chamber can force the flexible piston to move the drive means.

Multiple piece piston for an internal combustion engine

Abstract: A multiple piece piston is provided for a diesel internal combustion engine having a combustion chamber depression in the crown of the piston. In order to achieve a low rate of heat flow into the piston ring area and thus into the cylinder liner which surrounds the piston, a separate piston base or crown surrounding the combustion chamber depression is formed by a ring element made of a material having poor thermal conductivity, and the main body of the piston is made of a material with high thermal conductivity. The heat of combustion is thus conducted mainly axially through the piston main body and absorbed by sprayed cooling oil. The cooling oil, thus heated, can be utilized for heating purposes.

Control system for a supercharged internal combustion engine

Abstract: A control system for an injection-type internal combustion engine (1) with air compression is described, which engine is equipped with a supercharger, preferably with a supercharger (4) driven mechanically via a disconnectable coupling (13). This internal combustion engine has an exhaust gas recirculating system having a control valve (16), which is arranged in an exhaust gas recirculating line (15) connecting an exhaust manifold (3) to an induction manifold (2) of the internal combustion engine and which can be triggered by a control device (21) depending on characteristic state variables of the internal combustion engine. In order to extend the control and regulating range of this control system, it shall be possible for the control valve (16) to be triggered by the control device (21) to serve as an actuator for controlling exhaust gas recirculation in the lower load range of the internal combustion engine (1) and to serve as an actuator for controlling the boost pressure in the upper load range.

Method for introduction of charging air into the cylinder of an internal combustion engine and an engine for undertaking the method

Abstract: A method for the introduction of the charging air into the cylinder of an internal combustion engine, in the case of which pre-compressed air from a displacement charger is cooled by exchange of heat and is then expanded till the desired charging pressure has been reached. The expulsion motion of the piston or pistons of the displacement charger is so synchronized with the piston motion of the engine cylinder to be supplied that the air displaced from the charger transfers directly into the respective engine cylinder.

Internal combustion engine with a vibration-damped camshaft drive

Abstract: The invention relates to an internal combustion engine with at least one camshaft, which can be driven, optionally via an intermediate shaft, by the crankshaft. The non-uniform running of the crankshaft due to the nature of the valve train is damped and substantially decoupled by means of a vibration-damping element between the crankshaft and a camshaft.

Piston mechanics and kinematics of an axial engine

Abstract: Crankshaft drive for an engine, especially a diesel engine, with axial cylinder arrangement about a crankshaft with crank pin set at an angle and pistons running in the cylinders, on that side of which which is remote from the combustion chamber a piston pin is located, the non-positive connection between crankshaft and piston pin being made by individual connecting rods, which are designed so that at their end facing the crank pin they can rotate independently of one another about the crank pin axis or parallel to this and at the other end are supported so that they can rotate and slide in the piston pin.

Piston/power shaft coupling

Abstract: The conventional crank between the power piston and the crank shaft in a reciprocating engine is replaced by a fixed length moment arm during the power stroke and a scotch yoke during the return stroke. The motion of a power piston is converted to rotary motion at an output power shaft through the fixed length moment arm. The moment arm is the radius of a sector gear which is non-rotatably secured to the output shaft. The piston rod is modified to include a rack gear and a slot. The slot and the output shaft form the scotch yoke. The sector gear engages the rack only during the down stroke of the piston. The sector gear disengages just before the down stroke is completed. The piston is then timely returned to the precise position of its next stroke through the scotch yoke. The fixed length moment arm acts as a lever through the entire stroke of the pistion which reduces combustion pressure and temperature. The reduced combustion pressure permits a smaller combustion charge which saves fuel. The reduced pressure and combustion reduce exhaust pollutants. The stroke can be longer than the conventional crank, thereby applying the power through a greater angular displacement of the power shaft. Instant torque is achieved through the moment arm. The invention can be either the two or four stroke type.

Oscillating piston engine

Abstract: Except in aviation the reciprocating piston internal combustion engine is the universal power unit. In addition to its advantages the high state of development is the decisive factor in this. It is generally known, however, that the large overall size, the unfavourable power-to-weight ratio and the expensive crankshaft drive are some of the main disadvantages of the reciprocating piston engine. Although these negative characteristics have been overcome in the rotary piston engine, other, perhaps more serious disadvantages have had to be accepted. It is no longer possible to imagine aviation without the turbo jet engine as an alternative to the reciprocating piston engine, but in this design size it has so far not been sufficiently economic and cost-effective. The oscillating piston principle is intended to create the basic prerequisite for a new internal combustion engine which is smaller, lighter and cheaper than the reciprocating piston engine and in terms of its construction, size, operation and economic efficiency lies somewhere between the reciprocating piston and the Wankel engine. Except where the clear and significant advantages of the reciprocating piston and the rotary piston engine greatly outweigh their disadvantages, the oscillating piston engine could represent an alternative to both of these and have a wide sphere of application.

Engine with pressurized valved cell

Abstract: An internal combustion engine has an auxiliary cell connected thereto by a transfer valve. Approximately isothermally compressed gas, which may be a combustible mixture, is introduced into the cell through an input valve. A displacer piston in the cell is biased toward lower volume of the cell. In an illustrated embodiment, the displacer piston is translated by the compressed gas toward a larger volume in the cell. When the cell is fully charged with compressed gas, the input valve is closed and the transfer valve is opened for intermittently discharging the mass of gas in the cell into the cylinder of the internal combustion engine. The displacer piston displaces substantially all of the gas from the cell into the engine. Combustion is initiated and may, at least in part, occur within the cell, providing power to the engine as the gas expands and performs work by way of the engine piston. A two-stroke engine where the cell provides a compressed combustible mixture to the cylinder has enhanced efficiency since gas can be isothermally compressed instead of being compressed by the engine piston.

Two-stroke internal combustion engine, especially of reciprocating piston type

Abstract: A port-controlled two-stroke internal combustion engine, especially of reciprocating piston type, has an exhaust port with an additionally controlled pre-exhaust area, the control element of the pre-exhaust area having a contour over its width corresponding to the piston working surface for a tight interaction with a working piston. In order to obtain an inlet side boost suitable for any type of scavenging in port-controlled two-stroke internal combustion engines, the control element of the pre-exhaust area is periodically controlled in such a way that together with the working piston, it produces a closure of the entire exhaust port on the first stroke before the inlet port is completely closed.

Short pipe manifold for four-stroke engines

Abstract: A series of four-stroke engine manifolds for providing improved power and torque over a wide range of engine speeds are described A two-mode two degree-of-freedom resonator model for manifolds is described that predicts two individual torque peaks The model is shown to be valid only when two described dimensionless parameters, computer from the dimensions of the manifold and the engine to which it is attached, have minimum values If the two minimum values are not maintained, the correct resonator model collapses to a one degree-of-freedom system which provides only one, generally lower, torque peak By requiring minimum values for the two parameters, the resulting manifolds provide the desired improved power and torque The manifolds comprises two, three or four primary runners each connected at first ends to an engine cylinder and together at second ends to a secondary runner A primary volume is defined as the volume of an engine cylinder with its piston at midstroke A secondary volume is defined as the total volume of all primary runners, other than a primary runner attached to a first cylinder, and all cylinder intake ports, other than the intake port for the first cylinder The manifold dimensions are limited so that the runner coefficient, the ratio of the length-to-area ratio of the secondary runner divided by the length-to-area ratio of any primary runner, is at least 015; and, so that the volume coefficient, the ratio of the secondary volume divided by the primary volume is at least 20

Water cooled scavenged crankcase type otto internal combustion engine

Abstract: In an internal combustion type engine having a piston disposed within a cylinder, a plurality of ceramic cylinder inner surface sections are provided for covering surfaces of the cylinder chamber and the piston which are directly exposed to the ignited combustion gases as the piston travels through its stroke Same are for the protection of the metal structure of the engine from exposure to the heat generated within the cylinder

Double-acting two-stroke internal combustion engine

Abstract: The invention relates to a double-acting two-stroke internal combustion engine with at least one cylinder and a twin piston on a rectilinearly guided piston rod with exhaust ports in the middle area of the cylinder, with inlet devices to both working chambers and with at least one charging device connected to the inlet devices. Known combustion engines of this type are expensive in terms of their inlet control and function with unsatisfactory efficiency and high exhaust emission. According to the invention, a compact internal combustion engine functioning with high efficiency and low exhaust emission is created in that the piston rod is of continuous design with at least one hollow chamber and is guided in both ends of the cylinder and that a first flow connection is provided between the hollow chamber of the piston rod and the charge device and alternately open second flow connections are provided between the hollow chamber and each working chamber. In this way the hollow piston rod takes over the inlet control.

Four-stroke combustion engine with supercharging and method for operation thereof

Abstract: Four-stroke reciprocating piston combustion engine with supercharging and method for the operation thereof, whereby at the end of the driving out stroke flushing air is supplied under high pressure for the driving out of residual combustion gas in the exhaust pipe. The pressure in the exhaust pipe (7) is kept higher than the pressure in the inlet pipe (6), and the flushing air is taken from a separate source of air under high pressure. A flushing air supply line (10) is provided with a flushing air valve (12) and connected with a source of air under high pressure, and control means for controlling the flushing air valve syn­chronously with the piston movement such that at the end of the driving out stroke the air valve is opened briefly while the exhaust valve is still just open.

Method for the operation of a multicylinder four-stroke diesel engine of a compound internal combustion engine

Abstract: In a four-stroke diesel engine provided with turbocharger arranged as gas generator for an output power turbine, the combustion air of which engine is pre heated outside the cylinder, all the fuel is introduced in successively apportioned injection quantities (E1 and E2) throughout the expansion stroke.

Lubrication for a piston of a reciprocating piston internal combustion engine

Abstract: On the bottom edge of an oil scraper ring groove 22 of the piston of a reciprocating piston internal combustion engine, recesses 25 are fitted in the peripheral areas above the piston pin bosses, by means of which recesses excess oil is drained off or partially diverted by way of exit recesses 29 on the upper edge of the oil scraper ring groove 22 to the piston bearing face and minor thrust face.

Internal combustion engine with multiple crankshaft

Abstract: An internal combustion engine is described in which the individual cylinder arrangements are arranged circularly and parallel about an output shaft (60), each cylinder arrangement containing its own crankshaft drive (46), which is respectively connected by way of a bevel gear (46) to a bevel gear (61), located on the output shaft (60) and common to all crank arrangements of the individual cylinder arrangements. A small, compact internal combustion engine is thereby achieved, which can be manufactured with a power output of up to one HP per 450g approx. of engine weight. The drive shaft simultaneously serves as camshaft if the transmission between the individual crankshaft drives and the drive shaft has a ratio of 2:1 or a multiple thereof, for example 4:1, 8:1 etc.

Reciprocating engine piston seal

Abstract: Apparatus for sealing the gap between a piston and engine cyinder wall of either a reciprocating engine or a reciprocating compressor. The apparatus includes a plurality of functionally-identical, gas-bearing-supported seal blocks that locate in a slot running circumferentially around the engine piston. Gases fed from the engine chamber to the gas bearing carrying the load on the seal block in the direction of piston travel. The seal block includes a gas accumulator cavity for gas storage. An orifice feeds gas from the gas accumulator cavity to the gas bearing interfacing between the seal block and the engine cylinder wall. The apparatus also includes a reaction piston having gas communicated thereto from the engine chamber.