Showing papers on "Four-stroke engine published in 1991"

Internal combustion engine valve control device

Abstract: The present invention is a valve control device (10) for an internal combustion engine (12). It comprises a housing (18) having a piston chamber (20), in which is mounted a power piston (22) for reciprocating movement. The power piston (22) is connected to the engine valve (26). An air reservoir chamber (62) connected to a high pressure air source (74), is formed above the piston chamber (20). A poppet valve (42) mounted on the upper surface of the power piston (22) blocks communication between the piston chamber (20) and the air reservoir chamber (62) when the power piston (22) is in its highest position. The air source (74) is also connectred to the upper portion of the piston chamber (20) through a timing valve (76), which controls flow of air to the piston chamber (20).

Fuel pump and fuel filter for a marine installation

Abstract: An apparatus comprising a fuel pump, an internal combustion engine having an oil pressure and including an engine block and a crankshaft rotatably supported by the engine block, the apparatus further comprising structure for providing a first electrical signal while the engine is running, a starter selectively operable to rotate the crankshaft, structure for providing a second electrical signal while the starter rotates the crankshaft, and structure for causing the fuel pump to supply fuel to the internal combustion engine only while at least one of the first and second signals is present and without regard to the oil pressure of the internal combustion engine.

Free piston engine control system

Abstract: A control system for a variable stroke free piston engine, sets the ignition timing as a function of measured piston velocity. This velocity proportional ignition system provides spark advance on a stroke by stroke basis as an aid to starting the engine. Ignition changes over to a piston position based system when the engine is running at steady state. Fuel injection occurs at either piston dead point or is set as a function of piston position. Fuel injection is suppressed during cycles were the ports are not uncovered. The control system can also regulate compression ratio based upon piston position or knock sensor data. The preferred control system includes a hybrid digital analog system which includes a microprocessor.

Internal combustion engine with variable combustion chambers and increased expansion cycle

Abstract: An internal combustion engine and method for operating the same wherein the combustion chamber volume can be varied depending on throttle position by a member that is inserted into the combustion chamber, and wherein the intake valve is closed before the piston completes its intake stroke so that the expansion stroke is effectively lengthened. In the case of a two-stroke engine, some of the intake gas is expelled before combustion to achieve an effective lengthening of the expansion stroke.

Variable horsepower output gearing for piston engine

Abstract: A piston engine has at least one cylinder and one piston, a crankshaft and gearing apparatus that has a set of two or more traveling gears fixed together which are rotating on a crank that belongs to: 1) either the crankshaft itself, 2) either an extended part of the crankshaft, or 3) to an auxiliary shaft which is geared to the said crankshaft. One of the traveling gears is of irregular design and travels in a periodical way against a non-rotating internally toothed ring. The second traveling gear is of regular form and meshes with a rotating output ring, which in turn drives an output shaft which can be used as an output instead of the regular crankshaft and provides an alternate non regular pattern of piston displacement relative to output shaft rotation. The gearing apparatus provides a volume expansion rate in the cylinder which is conducive to efficient combustion.

Engine exhaust gas recirculation system

Abstract: An engine exhaust gas recirculation system has an intake passage (2) connected to feed an air/fuel mixture to an internal combustion engine and an exhaust passage (1) connected to discharge an exhaust gas from the internal combustion engine. An exhaust gas recirculation passage (3) is provided for feeding a portion of the exhaust gas of the exhaust passage into a cylinder of the engine such that a laminar distribution is produced in the cylinder formed by air/fuel mixture adjacent to the ignition plug and the recirculated exhaust gas distributed about the air/fuel mixture. The exhaust gas recirculation passage may open in the vicinity of an intake valve of the engine or open into the cylinder above the bottom dead center of the piston. The flow of recirculated exhaust gas may be controlled by pressure, for example by the inlet and exhaust valves of the engine and/or by a pressure control valve (31, 34). Alternatively, the exhaust gas recirculation may be controlled in a multicylinder engine by a distributor (20) which may be controlled by an engine "roughness" control signal. The EGR may be computed from outputs of an air flow sensor (7) and an intake manifold pressure sensor (50).

Controlled variable compression ratio internal combustion engine

Abstract: An improved arrangement for controlling and adjusting the compression ratio of an internal combustion engine (10) during operation. A secondary cylinder (201) is formed in the engine cylinder head (102) and opens upon the combustion chamber (110) of the engine. A secondary piston (203) is positioned by a control device (503) within the secondary cylinder (201). The rear most position corresponding to the lowest compression ratio. The desired position of the secondary piston (203), that compression ratio which corresponds to maximum efficiency of the engine, is controlled by a logic unit (816) operating upon such inputs as the engine load as correlated to the input manifold pressure, the engine RPM and the present position of the secondary piston (203). The linkage of the control may utilize a servo motor or hydraulic driver to rotate a shaft (301). All secondary pistons (203) may be operated in unison or a control system may be provided for each cylinder (201). An involute surface (302) mounted on the shaft (301) pushes the spring (204) loaded secondary piston (203) into the secondary cylinder (201). A worm gear (602) on the shaft (301) may turn a threaded bolt (603) to position the secondary piston (203). Or, a worm gear (813) may engage a gear (814) formed on the involute (815) to directly position the involute surface (815).

Method for controlling a crankcase scavenged two-stroke engine during deceleration fuel cut-off

Abstract: A method is described for increasing engine braking, when a crankcase scavenged two-stroke engine is operated in a deceleration fuel cut-off mode. In response to the detection of operating conditions indicating engine operation in the deceleration fuel cut-off mode, the quantity of air inducted into the engine is decreased, for a predetermined period of time. After this period of time elapses, the quantity of air inducted into the engine is then increased. This is preferably accomplished by regulating the degree of opening of a throttle valve disposed within the engine air intake system. The initial closing of the throttle valve restricts air flow through the engine for a predetermined time, to maintain efficient catalyst operating temperatures in the engine exhaust system. During extended operation in the deceleration fuel cut-off mode, the throttle valve is opened, after the lapse of the predetermined time, to increase the quantity of air inducted by the engine. This results in increased engine braking, due to the additional work that must be performed in compressing the larger quantity of inducted air.

Dual cycle engine process

Abstract: The invention relates to new and useful improvements in the exhaust and induction processes of the piston driven internal combustion engine. In the invention a gas ejector is used in conjunction with a poppet valve to control the induction of air and the discharge of combustion gases through a common duct within the engine cylinder head. The common duct is brought into communication with the clearance volume above the engine piston by rotation of the engine camshaft which is made equal to the rotation of the engine crankshaft, such that the poppet valve is operated at twice the cycle frequency required for four-stroke operation in the conventional engine. By operating the valve at this cycle frequency, and by the employment of gas ejector systems at the cylinder head above the poppet valve, and at another position on the engine cylinder near the bottom dead center of the engine piston travel, the engine is able to function interchangeably as a four-stroke or as a two-stroke system while running. This is done automatically by use of an electronic timing circuit which controls the rate of fuel injection and spark ignition with the use of an engine speed sensor placed in parallel or in series circuit with a second sensor which monitors system pressure in the clearance volume above the piston.

Dual-mode induction system

Abstract: A dual-mode induction system for a multi-cylinder internal; combustion engine wherein an individual intake passage or runner communicates between a common air plenum and each engine cylinder. A separate bypass having an individual port at each engine cylinder extends from the plenum and each internal runner to provide a substantially shorter passage to each engine cylinder and a valve covers each bypass port and is operated in response to engine speed and/or related vehicle operating parameters to simultaneously close the bypasses at low engine speed to force intake air through the longer internal runners and provide a ram tube effect and to simultaneously open the bypasses at high engine speeds to force intake air through the shorter internal runners at a higher frequency and low resistance.

Exhaust gas cleaning installation for four-stroke engine - includes electronically controlled feedback from exhaust to inlet manifold according to speed, temp., flow and vacuum

Abstract: The exhaust feedback arrangement is used in conjunction with a lambda-controlled three-way catalytic converter, enabling the engine to operate in lean-burn mode (with lambda greater than 1) under light loading. The feedback is controlled by a NOx detector. An electronic control program for the engine is selected in accordance with the power demand represented by the position of the accelerator pedal for less than full load. ADVANTAGE - Compliance with statutory pollutant emission limits is guaranteed with fuel consumption reduced by up to 10%, without loss of power output.

Compression release brake with variable ratio master and slave cylinder combination

Abstract: A method and apparatus for braking a multicylinder diesel engine. Some compressed gases are released from each engine cylinder near top dead center of each compression stroke on each cycle of the engine by forcing open the exhaust valve with a slave piston assembly of a two-stage master and slave cylinder combination. The slave piston assembly is moved by a master piston assembly which operatively engages an engine component which moves prior to top dead center of each compression stroke. The ratio of the area of the master piston assembly to the slave piston assembly is then increased and the exhaust valve is then opened to a preset fully cracked open position during a second stage of the master and slave cylinder combination. Loading on the engine component is reduced during the first stage and the rate of opening the exhaust valve is increased during the second stage when the force required to further open the exhaust valve has been reduced.

Four cycle engine

Abstract: A multiple valve internal combustion engine and specifically a cylinder head and valve operating mechanism therefore. The cylinder head is formed from a two part construction and an arrangement is provided for operating the valves that permits a maximum volume cooling jacket to be formed on the exhaust side of the cylinder head. The camshaft and tappet mechanism for operating the valves is formed in a second cylinder head portion and a port extends through both cylinder head portions for serving the combustion chamber of the cylinder head. Various cam drive arrangement including either gear or chain drives are also disclosed.

Valve-controlled internal combustion engine

Abstract: A valve-controlled internal combustion engine has an device 13 for adjusting the camshaft 2 relative to its timing gear 14. The adjusting device has an operating sleeve, which is interlocked over different gear systems, on the one hand, with the timing gear and, on the other, with the camshaft, and a hydraulic adjusting piston, which can be acted upon on both sides. Pressure is caused to act upon the adjusting piston by means of the engine oil, which is circulating under pressure and which is branched off before a restrictor 11 in the inflow to the bearings 12 in the cylinder head 2 of the internal combustion engine. By these means, the full pressure of the lubricating pump 7 can be used to shift the operating sleeve.

Method of electronic engine control for internal combustion engine having a plurality of cylinders

Abstract: A method of an electronic engine control for an internal combustion engine having a plurality of cylinders, wherein the very same air fuel ratio feed back coefficient obtained at a predetermined sequential timing which has been used for calculating the amount of fuel to be injected to a specific cylinder is also used for correcting timing of ignition for the same cylinder which follows immediately after the calculated amount of fuel has been injected into the specific cylinder, thereby the engine torque fluctuation is effectively suppressed, stability of engine operation during idling operation is improved and the surge during a low speed running is prevented.

Identification of combustion engine ignition or injection phase - comparing desired with actual reaction of four-stroke engine to operations at appropriate crankshaft angular position

Abstract: The crankshaft (2) carries a toothed disc (5) with angular graduations (3) and a mark (4) corresp. to the TDC position of the piston in one of the four cylinders. A pick-up (6) close to the rim of the disc (5) sends a signal once per revolution to a speed processor (7). A comparator (8) is connected to an electronic unit (9) for individual retardation of the pulses applied from coils (10-13) to the separate sparking plug leads (14-17). ADVANTAGE - Rotational angle corresp. to ignition or fuel injection can be identified without recourse to second pick-up on e.g. camshaft.

Fault-tolerant controller for four-stroke combustion engine - extracts different evaluation and control pulse widths from modified camshaft pulse sequence for emergency running

Abstract: The controller uses a pin on the flywheel to produce a reference signal once per revolution of the crankshaft (KW) 62 deg. before TDC of a selected cylinder (I), while the teeth produce 135 pulses per crankshaft revolution. For cylinder recognition a phase detector produces a camshaft (NW) signal of defined tolerance whereby the low-phase pulse widths for particular cylinders (I,VI) correspond to 80 and 35 deg. of crankshaft rotation respectively while those for other cylinders (II-V) are of uniform width corresp. to 57 deg. rotation. ADVANTAGE - Emergency running is guaranteed in event of failure of crankshaft, reference or camshaft signals.

Four cycle engine

Abstract: PURPOSE: To enable lean burn in an exhaust gas contained condition to be conducted, and improve fuel consumption by changing an air fuel ratio of air- fuel mixture supplied to one divided combustion chamber though air-fuel mixture of a theoretical air fuel ratio is supplied constantly to the other divided combustion chamber. CONSTITUTION: At least in one of cylinder heads and pistons, partition walls 14 are formed throughout respective central positions where respective two air intake valves 11A and 11B and air exhaust valves 12A and 12B, so that a combustion chamber is divided into two parts. Air fuel mixture of a theoretical air fuel ratio is supplied to one divided combustion chamber 5A, and exhaust gas contained air-fuel mixture is supplied to the other divided combustion chamber 5B. The air fuel ratio of this exhaust gas contained air-fuel mixture is set to be changed according to an engine load. Thereby, besides making a driving feeling excellent by operating the whole cylinders, fuel consumption can be also reduced by enabling lean burn. COPYRIGHT: (C)1993,JPO&Japio

Measurement of Cylinder Bore Deformation by means of a Turning Piston with a Gap Sensor during Engine Operation

Abstract: Measurements of cylinder bore radial deformation were made along the peripheral direction during actual engine operation. A piston, whose upper part was capable of turning, was installed on the pin boss and was slowly turned from an outside power source by means of a gear train. A heatproof inductance-type gap sensor was embedded on the second land surface. When the engine was under steady-state operation, the piston position at any crank angle was fixed every cycle, not only axially but also inside the corresponding cylinder cross section. As a result, the cylinder bore deformation was continuously measured by one sensor along its entire periphery at one desired axial piston position. One of the important measurement results was that the compound effect of head bolt force and thermal stress had a significant influence on the bore deformation.

Valve timing control system of internal combustion engine

Abstract: A valve timing control system of an internal combustion engine having a camshaft for operating intake or exhaust valves. The valve timing control system is comprised of a cylindrical sprocket driven through a timing chain by a crankshaft of the engine. An arm is fixed to one end of the camshaft and located inside the sprocket in a manner to extend generally diametrically. An annular piston is movably disposed coaxially with the camshaft and inside the sprocket to define an oil pressure chamber. The piston is moved axially by controlling the oil pressure to be supplied to the oil pressure chamber, in accordance with an engine operating condition. At least three sliders are supported to the piston to move with the piston. Each slider has an inclined face which is in slidable contact with a side face of the arm. This inclined surface is adapted to push the arm to rotate around the axis of the camshaft when each slider is moved axially upon the axial movement of the piston. The rotation of the arm causes the camshaft to make its relative rotational movement to the driven sprocket, thereby changing the opening and closing timings of the intake or/and exhaust valves.

Compression ratio control in gasoline engines

Abstract: A compression ratio control system consists of a two-part piston forming a hydraulic chamber between the two slidable parts; their relative position, which determines the piston height, is controlled outside of the engine by regulating the pressure of engine oil going to the crankshaft and channeled to the hydraulic chamber through the crank mechanism. Piston height adjustment is accomplished incrementally by balancing the oil pressure against the momentary cylinder pressure transmitted to the hydraulic chamber, for a short interval at a predetermined angular crankshaft position, using a timing device located at the crankshaft end of a piston rod. The timing device consists of a set of small valves operated by inertial forces; with respect to the oil flow, these valves are arranged in series and on different timing given by their angular orientation, so as to open the oil passage during their opening overlap once per cycle.

Compound four stroke internal combustion engine with crossover overcharging

Abstract: A normally aspirated compounded, overcharged (supercharged) four stroke internal combustion engine, preferably diesel, which is particularly useful in adiabatic (low heat rejection) versions. An auxiliary expansion piston and compression piston reciprocate at least twice as fast as the combustion pistons to increase the volumetric efficiency of the engine as well as to overcharge the air charge within the combustion cylinders. Increased efficiency and simplified construction result.

Internal combustion engine with multiple combustion chambers

Abstract: An internal combustion engine having two separate main combustion chambers isolated from the cylinder and from each other by means of a valve throttle mechanism. Combustion occurs first in one chamber, and then in the other, separated by one complete revolution of the crankshaft in the two-cycle embodiment and two complete revolutions of the crankshaft in the four-cycle embodiment. The alternative operation effectively removes the combustion process from the cycle for a sufficient amount of time to enable the combustive reactions to approach chemical equilibrium prior to release in the cylinder.

Modelling, Parameter Selection and Simulation of a Single-Cylinder Four-Cycle Engine

Abstract: This paper describes the procedure involved in developing a simulation model of a single-cylinder four-cycle engine, suitable for fuel injection control system studies. In particular, the modelling procedures and methods of parameter selection, including supporting experimental work, are indicated. Responses obtained from the simulation model are then compared with those obtained experimentally from the engine. Finally, future improvements to the model are suggested.

Valve system of four-cycle engine

Abstract: PURPOSE:To smoothly change over cams from a low speed cam to intermediate and high speed cams at the time of accelerating an engine by setting the number of rotations where an engine output is effectively utilized. CONSTITUTION:A low speed rocker arm 7 which is directly inserted into a rotatably supported rocker shaft 11 and intermediate and high speed rocker arms 8,9 inserted into an eccentric large diameter part of the rocker shaft 11 are provided. In addition, a low speed cam for actuating the low speed rocker arm 7 and intermediate and high speed cams 4,5 for actuating the intermediate and high speed rocker arms 8,9 are provided. Further a rocker shaft driving source for selectively switching the actuation of the low speed cam 3 and the actuation of the intermediate and high speed cams 4,5 is provided. A driving source controller controls switching of the cams by setting the number N1 of rotations for switching at the time of acceleration to switch the cam actuation at the time of accelerating an engine to the number of rotations which is the number of engine rotations at an intersection of engine output characteristics A by the low speed cam and engine output characteristics B by the intermediate and high speed cams or less with actuation delay time T of the rocker shaft driving source, etc., taken into consideration.

IC engine crank drive system - incorporates gears to give dwell period near TDC

Abstract: The reciprocating IC engine has a piston joined by a connecting rod (4) to a crankshaft (5) in which for each piston a separate crankshaft is provided. A planetary gear carrier (6) is mounted in the crankcase (1) and comprises a left and a right bearing piece (7,8) with a coaxial gear crown (12), joined to a torque transmission element (23), and meshing with a sun wheel (14). USE/ADVANTAGE - IC engine which has a comparatively long dwell time for the piston near the top of the stroke.

Method for the pneumatic injection of fuel into a two stroke engine and corresponding two stroke engine

Abstract: An engine including at least one cylinder in which a piston moves delimiting a combustion chamber and a housing, with at least one opening for allowing fresh air to enter the combustion chamber and one pneumatic injection device. The fuel is atomized or sprayed and injected into the chamber by using a compressed gas. For small engine charges, a compressed gas is used, with the compressed gas being derived solely from the chamber or the housing of the cylinder of the engine, and for high engine charges, another compressed gas is used derived from a source outside the cylinder. The source outside the chamber may include a mechanical compressor driven by one of a two-stage engine or a turbocompressor.