Showing papers on "Four-stroke engine published in 2001"

Experimental Studies on Controlled Auto-ignition (CAI) Combustion of Gasoline in a 4-Stroke Engine

Abstract: This paper presents results from an experimental programme researching the in-cylinder conditions necessary to obtain gasoline Controlled Auto-ignition (CAI) combustion in a 4-stroke engine. A single-cylinder, variable compression ratio research engine is used for all experiments. Investigations concentrate on establishing the CAI operating range with regard to Air/Fuel ratio and Exhaust Gas Re-circulation (EGR) and their effect on ignition timing, combustion rate and variability, ISFC, and engine-out emissions, such as NOx, CO, and unburned HC. Comprehensive maps for each of the measured variables are presented and in relevant cases, these results are compared to those obtained during normal spark-ignition operation so that the benefits of CAI combustion can be more fully appreciated. Copyright © 2001 Society of Automotive Engineers, Inc.

Research and Development of Controlled Auto-Ignition (CAI) Combustion in a 4-Stroke Multi-Cylinder Gasoline Engine

Abstract: Copyright © 2001 SAE International This paper is posted on this site with permission from SAE International Further use of this paper is not permitted without permission from SAE

Method and apparatus for gaseous fuel introduction and controlling combustion in an internal combustion engine

Abstract: A method and apparatus for introducing gaseous fuel into a piston cylinder of an operating internal combustion engine in two separate stages involves monitoring a set of engine parameters, determining engine load and engine speed from the set of engine parameters, in a first stage, introducing a first portion of the gaseous fuel into the cylinder where the first portion of gaseous fuel forms a substantially homogeneous mixture comprising gaseous fuel and air prior to combustion, and in a second stage, occurring sequentially after the first stage, introducing a second portion of the gaseous fuel into the cylinder. The gaseous fuel quantity is variable in response to at least one of engine load and engine speed. Initiation and duration for at least one of the first and second stages is also variable in response to at least one of engine load and engine speed.

Cylinder injection type internal combustion engine, control method for internal combustion engine, and fuel injection valve

Abstract: There is provided a cylinder injection type internal combustion engine capable of performing stratified charge operation at the time of a vehicle speed of 120 km/h and/or an engine rotational speed of 3200 rpm to enhance the fuel efficiency and/or to observe the emission regulations. In the internal combustion engine, a stratum of air and/or air flow is formed between a fuel spray injected from an injection valve and the top face of a piston and/or the wall surface of a combustion chamber, and a face shape contrived to guide the air flow is formed on the top face of the piston. Also, the stratified charge operation can be performed even at the time of cold start or cranking.

Method for starting a multi-cylinder internal combustion engine

Abstract: The invention relates to a method for starting a multi-cylinder internal combustion engine (1), especially of a motor vehicle, whereby the position of a piston (2) in a cylinder (3) of the internal combustion engine (1) is determined and fuel is injected into a combustion chamber (4) of the cylinder (3) whose piston (2) is located in a working phase In order to enable a starting of the internal combustion engine (1) without the use of an electric motor-driven starter in a manner that is as reliable as possible, the invention provides that that the intake valves and/or exhaust valves (5) of at least one cylinder (3), whose piston (2) is located beyond an upper dead center (OT), are brought, before the starting process, into a position that corresponds to a working phase

Engine cycle and fuels for same

Abstract: An engine cycle that is carried out in a reciprocating piston/cylinder engine consists of a working stroke in which exothermic decomposition of at least one liquid compound is caused to occur without combustion so as to produce a gaseous product of the composition that drives the piston along the cylinder in one direction and an exhaust stroke in which the products of the decomposition are exhausted from the cylinder upon return movement of the piston.

Handheld type four-cycle engine

Abstract: In a handheld type four-cycle engine, a valve operation mechanism includes a camshaft rotatably supported in a cylinder head so as to open and close an intake valve and an exhaust valve and a timing transmission placed on one side outside an engine main body and providing association between a crankshaft and the camshaft, and a centrifugal clutch for power output is mounted on the crankshaft on the opposite side outside the engine main body. The timing transmission and the centrifugal clutch being positioned at the two ends of the crankshaft improves the weight balance, the centre of gravity of the engine can be made as close to the central part of the crankshaft as possible, which, together with the reduced weight, can enhance the operability of the engine.

Apparatus and method for early intake valve closing

Abstract: A method for early intake valve closing in an internal combustion engine having a crankshaft and at least one exhaust valve, the crankshaft having a top dead center position and a bottom dead center position, includes the step of determining engine operating load conditions and parameters. One of a plurality of predetermined valve lift profiles, each of which correspond to a respective range of engine operating load conditions and parameters, is selected dependent at least in part upon the engine operating load conditions and parameters. The engine is commanded to operate the engine intake valves according to the selected one of the plurality of predetermined valve lift profiles to thereby optimize fuel economy and reduce emissions at light to moderate engine loads, to improve torque and power at relatively full engine loads, and improve cold start engine operation under cold start engine conditions.

Arrangement for internal combustion engine controlled shut-down, has electrical machine with arrangement providing variable torque after engine shut down to give smooth engine rundown

Abstract: The crankshaft of the internal combustion engine interacts with an electrical machine and can receive a torque from the machine under defined conditions. The electrical machine has an arrangement that provides a variable torque after the internal combustion engine is shut down so as to achieve a smooth rundown of the internal combustion engine. AN Independent claim is also included for the following: a method of controlled shut-down of an internal combustion engine.

4-cycle engine

Abstract: A 4-cycle engine includes an oil tank mounted to one side of an engine body, and an oil slinger accommodated in the oil tank and adapted to scatter an oil stored in said oil tank to generate a lubricating oil mist. In the 4-cycle engine, a timing transmitting case is interposed between the engine body and the oil tank, so that heat transmission from the engine body to the oil tank is shielded. Thus, the oil tank can be disposed at a location spaced apart from the engine body without bringing about an increase in size of the engine, thereby suppressing the heat transmission from the engine body to the oil tank to the utmost to prevent overheating of the oil in the oil tank.

Conceptual analysis of a four -stroke linear engine

Abstract: CONCEPTUAL ANALYSIS OF A FOUR-STROKE LINEAR ENGINE By Sorin Petreanu During the past five years at West Virginia University, research into new auxiliary power generation devices has led to the development of a novel crankless reciprocating internal combustion engine. This dissertation presents a conceptual design of a Four-Stroke Linear Engine based on the numerical simulation of the operation of this type of linear engine. The engine consists of four opposed pistons linked by a connecting rod to a linear alternator. A series of numerical simulations was developed and employed to investigate the operation and performance of this crankless, four stroke linear engine. Since this linear engine is crankless, the numerical analysis of this particular engine is a time-based analysis. Two numerical models permit the simulation of the Four-Stroke Linear Engine employing Direct Injection Compression Ignition mode and a Homogeneous Charge Compression Ignition (HCCI) mode. The engine computational model combines dynamic and thermodynamic analyses. A detailed analysis of the engine operation range allows results to be obtained from a parametric study. The parametric study was performed to predict the engine behavior over a wide operating range, given intake parameters, variations in fuel combustion properties, reciprocating mass of the piston shaft assembly, frictional load and the externally applied load, and injection and valve timing. Based on the parametric study a conceptual design for a 15 kW linear engine was developed, showing the effects of reciprocating mass and air to fuel ratio on frequency of operation, power output, and efficiency. The engine analysis shown that this engine has a limited range of operation. The engine operating in as a direct injection compression ignition permitted high efficiency with values between 46 and 49 % corresponding to a compression ratio range between 17 and 35. The analysis performed for the engine operating as a HCCI mode revealed that this particular operating mode depends critically on the start of combustion, which depends in turn on piston motion which is not prescribed. Although the HCCI operation permitted to achieve high values of the efficiency (over 60%) and power output it was observed that the operation domain for the engine was much narrower than for the direct injection case. The results obtained from the numerical simulation show that the FSLE operating under HCCI is difficult to control and this observation extends to any mechanical arrangement of the linear engine with unconstrained piston motion.

Fuel injection system for a two-stroke engine

Abstract: An internal combustion, two stroke engine is disclosed. The engine includes a crankcase with a cylinder adapted to house a piston. At least one transfer duct communicates the crankcase to the cylinder. At least one fuel injector is disposed through a wall of the transfer duct. The fuel injector is positioned to inject fuel tangentially to the cylinder.

Exhaust system for 4-cycle engine of small watercraft

Abstract: An internal combustion engine, which can be disposed in a water vehicle, includes an exhaust system having features improving the performance, ease of manufacturing, and/or the water preclusive effects thereof. The exhaust system can include an exhaust manifold defining a plurality of exhaust runners and being made from at least two parts. The exhaust system can also include a plurality of individual exhaust passages extending from exhaust ports of the engine to a forward end of the engine. The exhaust system can also include an exhaust passage which extends from the exhaust ports to varying elevations relative to the exhaust ports, as well as other features.

Variable valve timing and lift structure for four cycle engine

Abstract: A variable valve timing and lift structure for a four-cycle internal combustion engine wherein a high speed and low speed cam are associated with the camshaft, each for operating the same valve. The high speed cam is supported for movement relative to the camshaft and this movement includes relative rotation. A coupling device selectively couples the second cam for rotation with the camshaft so as to operate the valve during at least a portion of its opening and closing movement when so coupled. When the second cam is not so coupled, the first cam controls the entire motion of the valve. The first and second cams are related so that at least one of these cams can operate two adjacent valves for the same cylinder, thus simplifying the overall construction.

Osband super inductionexhaustion valveshaft' engine system, V-type, flat-type, single-type, multi-cylinder four-cycle engine(s)

Abstract: An internal combustion engine; having block valley radiator core, with electrical water pump and air cooling fans, cooling and circulating water through block water passages, and having block valley oil reservoirs positioned under block valley radiator core for oil storage cooling and directing oil through oil passages. Includes; cylinderhead having horizontally rotating valveshaft; having separate axially spaced intake and exhaust valvepockets between ringseals, being timed rotated, centrally above dual spark plug ignition combustion chambers, over piston cylinders, and communicating centrally between cylinderhead intake and exhaust chambers—having port passageways, with connected intake and exhaust manifolds, providing strainfree; opening and closing combustion chambers, highspeed valvepocket(s) rotation, highflow air-fuel intaking and combustion exhausting—velocity capabilities. The valveshaft provides installation and removal without removing cylinderhead from engine block. The valveshaft(s) rotates by; mounted pulleygear(s) and belt(s), linking to a drive pulleygear(s)—being rotational supported in front engine mounted—oil cooling pump casing—having internal oil pumping pinion drive gear(s), driven by the crankshaft.

Free piston engine and self-actuated fuel injector therefor

Abstract: A simple propulsion engine utilizing unheated atmospheric air as the propellant, and driven by a single cycle (unicycle) engine with internal combustion cylinder and free piston is disclosed. A free piston with an annularly arranged thrust piston to divide a dual-diameter cylinder into two combustion chambers and two thrust chambers is provided. Scavenge feeder lines connected the thrust chambers to the combustion chambers via check valves provide exhaust scavenging, additional thrust output through exhaust nozzles, and feeding of fresh air into the combustion chambers. Also, pressure-actuated fuel injectors utilize pressure changes in respective combustion chambers to inject fuel at the appropriate time. The fuel injector includes an intensifier piston and pintle to raise the fuel pressure.

Rotation control apparatus for internal combustion engine

Abstract: A control apparatus for suppressing vibrations of an engine when combustion is stopped. The control apparatus maintains an engine rotational speed at a reference rotational speed for a reference time when the combustion of the engine is automatically stopped. This results in a reduction in pressure in a combustion chamber of the engine. The control apparatus gradually reduces the rotational speed of the crankshaft, and stops the crankshaft before the rotational speed of the crankshaft reaches a resonant speed. In this way, the resonance and increased pressure in the combustion chamber are prevented to reduce vibrations of the vehicle.

Operator carried power tool having a four-cycle engine and an engine lubrication method

Abstract: An engine powered hand-held power tool and engine lubrication method is provided, the power tool being intended to be carried by an operator during use. The power tool has a frame, including a handle to be grasped by the operator, an implement affixed to the frame having a rotary input member, and a small four-cycle, lightweight, internal combustion engine attached to the frame for driving the implement. The four-cycle engine has a lightweight aluminum alloy engine block having a cylindrical bore and an enclosed oil reservoir formed therein. A crankshaft is rotatably mounted in the engine block for rotation about a crankshaft axis. A piston reciprocates within the bore and is connected to the crankshaft by a connecting rod. An oil splasher driven by the crankshaft intermittently engages the oil within the enclosed oil reservoir to splash-lubricate the engine. The engine is provided with a cylinder head assembly defining a compact combustion chamber having a pair of overhead intake and exhaust ports and cooperating intake and exhaust valves. A lightweight, high-powered engine is thereby provided having relatively low HC and CO emissions.

Internal combustion engine with a supercharger and an improved piston crank mechanism

Abstract: A supercharged internal combustion engine is provided with a double-link type piston crank mechanism connecting between a piston and a crankshaft. The piston crank mechanism causes the piston to move at a speed which is smaller around a top dead center (TDC) and larger around a bottom dead center (BDC) as compared with respective corresponding piston speeds attained by a comparable single-link type piston crank mechanism. The double-link type piston crank mechanism variably controls a compression ratio by varying an angular position of one of links constituting the piston crank mechanism.

Computer Simulation of a Four-Stroke Spark Ignition Engine

Abstract: This paper introduces the preliminary simulation of a four stroke spark ignition engine. An arbitrary heat release formula was used to predict the cylinder pressure, which was used to find the indicated work done. The heat transfer from the cylinder, friction and pumping losses also were taken into account to predict the brake mean effective pressure, brake thermal efficiency and brake specific fuel consumption. Most of the parameters that can affect the performance of four stroke spark ignition engines, such as equivalence ratio, spark timing, heat release rate, compression ratio, compression index and expansion index are studied. The use of a real combustion curve has a profound influence on the similarity of the pressure–volume profile to that seen for the real engine. The modeling process is obviously getting closer to reality and is now worth pursuing as a design aid.

Variable compression ratio control system for an internal combustion engine

Abstract: An internal combustion engine has a mechanism to control the compression ratio of the combustion chamber. The mechanism includes an eccentric journal bearing supporting each piston rod on the crankshaft of the engine. The journal bearing has a gear member secured thereto that meshes with an inner toothed profile of a ring gear which has an outer toothed profile that meshes with an engine-driven gear. The speed of the engine-driven gear is controllable through a differential gear mechanism to adjust the relative position of the eccentricity of the journal bearing relative to the crank throw on which it is supported. This will change the compression ratio of the combustion chamber of the engine. The mechanism, with a modification, can also be employed to control the maximum compression pressure or the maximum combustion pressure in the combustion chambers of engine.

Internal combustion engine with two exhaust gas turbochargers and compressor bypass, has engine output torque held essentially constant when opening bypass by internal engine intervention

Abstract: The engine has at least one high pressure (2) and at least one low pressure (3) stage and a bypass (4) for the high pressure compressor (5) of at least one high pressure stage. A control unit (9) controls the opening and closing of the bypass depending on different engine speed-load characteristic opening and closing thresholds. The engine output torque is held essentially constant when opening the bypass by internal engine intervention. AN Independent claim is also included for the following: a method of operating an internal combustion engine for a motor vehicle.

Lubricating method and device of internal combustion engine

Abstract: An object of the present invention is to provide an improved lubricating method and device for the internal combustion engine, which allows the engine to be lubricated by taking advantage of engine vibration without using other power source. The lubricating device includes a crankcase separated into a crank chamber and an oil reservoir by a partition wall. The partition wall has an opening provided with a wire net for covering the opening. A coil spring is suspended within the oil reservoir so as to form a U-shape. During operation, an engine vibration induces a vibration of the coil spring, and the oscillating coil spring agitates and/or splashes up an engine oil contained in the oil reservoir, and whereby an entire oil surface is ruffled. The engine oil introduced into the crank chamber impinges on a crankshaft and finer droplets or oil mist is formed to thereby lubricate the crankshaft and other engine components.

Method and apparatus for diminishing the consumption of fuel and converting reciprocal piston motion into rotary motion

Abstract: An apparatus for converting between reciprocal piston motion and rotary shaft motion. A unique H-shaped piston rod configuration and corresponding cylinder assembly for improving the efficiency of internal and external combustion engines. A Stirling engine having improved efficiency due to the use of heat exchangers that are integral with the cylinder assemblies. A Stirling engine employing a novel apparatus for rapidly varying power output.

Piston assembly for use in a free piston internal combustion engine

Abstract: A piston assembly, particularly suitable for use in a free piston internal combustion engine, is provided with a piston including at least one oil coolant passage therein. The plunger shaft is substantially rigidly attached to the piston and axially extends from the piston. The plunger shaft includes at least one oil supply passage fluidly connected with at least one oil coolant passage.

Method of operating spark-ignition four-stroke internal combustion engine

Abstract: This invention relates to a method of operating a spark ignition four-stroke internal combustion engine (10) comprised of a valve train (14) and a crankcase (12) and equipped with an exhaust gas aftertreatment device (20), said method comprising: (A) operating said engine using a gasoline fuel composition, the exhaust gas from the operation of said engine being advanced through said aftertreatment device (20); (B) lubricating said crankcase (12) using a first lubricating oil composition, said first lubricating oil composition optionally containing an extreme-pressure additive comprised of metal and phosphorous, provided the amount of phosphorous contributed to said first lubricating oil composition does not exceed about 0.04 % by weight based on the weight of said first lubricating oil composition; and (C) lubricating said valve train using a second lubricating oil composition.

Cooling duct piston for a direct-injection diesel engine

Abstract: The aim of the invention is to obtain, with constant or increasing output, a reduction in the compression height of a cooling duct piston (1) for a direct-injection diesel engine. To this end, the piston (1) is composed of at least two parts (23) that are soldered together. One of the parts is a piston base body (2), which is forged of steel and which is provided with a shaft (8), hubs (6) and with an annular part (9). The other part, which is made of steel or of a nickel-based material, contains a combustion recess (4) and at least a portion of the piston head (5). The piston base body (2) and the second part (3), together, form a cooling duct (11) that can be filled with oil.