Showing papers on "Four-stroke engine published in 1977"

Peak cylinder combustion pressure ignition spark timing system

Abstract: The ignition spark events of the cylinders of an internal combustion engine are timed to provide peak cylinder combustion pressure at a predetermined engine crankshaft angle relative to piston top dead center. The engine crankshaft angle at which the peak cylinder combustion pressure of a selected monitored engine cylinder occurs during each power stroke thereof is detected and indicated by a logic signal. An electrical peak pressure error signal indication of the engine crankshaft angle difference between the crankshaft angle at which peak cylinder combustion pressure actually occurs and the predetermined desired engine crankshaft angle is electronically generated during the period of time required for the engine crankshaft to rotate through a constant predetermined engine crankshaft angle at all engine speeds. This signal indication is electronically processed by an electronic circuit combination which, in response thereto, adjusts the ignition spark timing in the direction to provide ignition spark events at the engine crankshaft angle which results in peak cylinder combustion pressure at the predetermined desired engine crankshaft angle.

Variable displacement internal combustion engine having automatic piston stroke control

Abstract: An internal combustion engine has a crankshaft offset to one side of the axis of the engine cylinder and an articulated connecting rod linkage operable to vary the stroke of the engine piston in accordance with engine operating conditions, so that different density fuel-air charges inducted into the cylinder will be compressed to substantially the same extent each time the cylinder is fired, regardless of throttle setting, engine speeds, or loads.

Fluid power supply system

Abstract: A double acting Diesel cycle hot gas engine comprising a plurality of engine cylinders, each having a free piston unit adapted to perform work, providing a continuous flow of compressed air to an energy consumption source and to a storage tank connected therewith. The free piston unit includes an air compression piston and a power piston, spaced apart from each other and adapted to move together within each respective engine cylinder through a connecting rod extended therebetween in response to the movement of a working medium under a substantially constant pressure acting against one side of the power piston and to the pressure and expansive power generated by the burning gases of an air fuel mixture acting on the opposite side of said power piston. Cycle control means are provided to release the potential energy accumulated within the working medium which is initially used to drive the power piston to compress the air fuel mixture and thus, initiating the operative cycle of the engine. The working medium is arranged into a hermetic compartment including a free floating piston adapted to perform work. The compartment has a volumeric capacity variable in response to the movement of the free piston unit within the engine cylinders, whereby energy in the form of compressed air is obtained through the movement of the free floating piston and the air compression piston respectively simultaneously and independently one from the other.

Four-stroke reciprocatory internal combustion engine and method of operating such an engine

Abstract: A four-stroke reciprocatory internal combustion engine has a scavenging phase in which air is admitted under pressure into the cylinder and has a swirl generating phase in which a high-speed jet of air is admitted under pressure into the cylinder so as to swirl air fuel mixture charge in the cylinder around the cylinder axis. The engine has, in addition to an intake valve that controls induction of air fuel mixture into the cylinder, a separate air inlet valve which effects the scavenging phase and swirl generating phase.

Variable displacement arrangement in four cycle, reciprocating internal combustion engine

Abstract: A compression spring coupling is provided between the engine piston and the crankshaft in a four cycle, reciprocating, internal combustion engine. This spring, when extended to the full extent permitted, is held compressed by a force equal to the piston force required to compress the fuel mixture for proper combustion under no load or very light load. Under no load on the engine the spring acts as a stiff coupling between the engine piston and the crankshaft. At heavier loads the spring is resiliently compressed in proportion to the load. The engine displacement is substantially smaller at no load and light loads than under heavy loads.

Indicated mean-effective pressure instrument

Abstract: There is disclosed an apparatus for measuring indicated mean effective pressure (IMEP) of an internal combustion piston or rotary engine or of an external combustion engine such as a stirling engine. An optical shaft encoder measures crankshaft angle of the engine. Changes in volume with respect to changes in crankangle of one or more cylinders (dV/dθ) is determined either empirically or algebraically from engine geometry and stored in a memory. As the crank angle changes, dV/dθ is read from the memory and multiplied by chamber or cylinder pressure. The product (P dV/dθ) is then added to the total previously accumulated in the cycle. Each time θ changes by an amount equal to delta θ, the process is repeated. At the end of each engine cycle, the total is equal to the IMEP value for that cycle.

V-Shaped forced air cooling 4-cycle engine

Abstract: An engine crankcase has oppositely inclined surfaces thereon, to which cylinders equipped with cooling fins are attached, to form a V-shaped engine. The crankcase has a crankshaft rotatably mounted therein, the front end of which projects from the front of the crankcase and has a cooling fan mounted thereon, the fan being housed within a cover adapted to pass cooling air backwards over the cylinders. A cam shaft is mounted vertically above the crankshaft, and the two are connected by gears mounted at the front of the crankcase. The rear end of the V-shaped region between the cylinders is open to provide for the escape of foreign matter, and the engine is balanced by locating the governor and the lubricant pump within the rear end of the crankcase.

System for retarding engine speed

Abstract: An engine retarder for a fuel injection engine wherein a charge of fuel is pumped to each cylinder under pressure in timed sequence to reach the cylinder near top dead center of its stroke. A selectively operated bypass valve enables that measured charge of fuel to be delivered at the same time in the cycle, not into the cylinder, but to an actuator which opens the cylinder's exhaust valve near the completion of the piston's compression stroke and then allows the valve to close, the charge of fuel being returned to the tank.

Internal combustion engine with stepped piston supercharger

Abstract: A reciprocating piston four cycle internal combustion engine utilizes a stepped piston the stepped portion of which, working in an enlarged bore in the block, serves as a compressor to provide a supercharged fuel-air mixture to the combustion chamber. The compressor delivers two compression strokes per engine cycle. The compressed fuel-air mixture travels from the compressor via a bypass manifold, which also serves as an accumulator, to the main cylinder via an intake valve. Fuel-air mixture is admitted to the compressor cylinder through the crankcase and valved passages through the stepped portion of the piston.

Braking device for four-stroke cycle reciprocating piston internal combustion engine

Abstract: A braking device for four-stroke cycle reciprocating piston internal combustion engines, especially vehicle engines, which for controlling at least each outlet valve include a hydraulically operable driving cylinder-piston unit adapted to be actuated by a camshaft, and a working cylinder-piston unit connected through at least one control conduit with the driving cylinder-piston unit and operable to actuate the outlet valve. The working cylinder-piston unit has a two-step different diameter cylinder and two plungers of correspondingly different diameters reciprocating relative to each other in the two-step cylinder. The braking device also includes a control member, e.g., a valve spool, common to all control conduits, for selectively connecting the control conduits to and disconnecting them from different driving cylinder-piston units and working cylinder piston units to thereby establish or interrupt connection between different driving cylinder-piston units with different working cylinder-piston units. The larger plungers only of the two plungers of the working cylinder-piston units are adapted to be acted upon by pressure fluid to reduce the opening stroke of the discharge valves.

Study of Mixtures of Methane and Carbon Dioxide as Fuels in a Single Cylinder Engine (CLR)

Abstract: A single cylinder four stroke engine (CLR) was used. to investigate the feasibility of using mixtures of methane and carbon dioxide as an alternate fuel. Effects of fuel quality on engine power output and brake specific fuel consumption were investigated at 800, 1600, 2400, 2800 and 3200 rpm using full throttle setting with various spark timing, equivalence ratio and maximum load. Results indicated that using fuel mixtures having quality of 65/35 or better in methane and carbon dioxide ratio along with optimum spark timing and operating equivalence ratio corresponding to maximum fuel economy, engine power losses and brake specific fuel consumption increases could be kept below 10% compared to the maximum power produced with pure methane fuel.

Method and apparatus for carrying out the method to control a multi-cylinder internal combustion engine

Abstract: A method and apparatus for controlling a multi-cylinder internal combustion engine by connecting or disconnecting one or several of the cylinders with a throttling device provided in the suction system of the internal combustion engine; simultaneously with the connection or disconnection of the cylinder or cylinders, the position of the throttling device is so changed jump-like that the output of the internal combustion engine remains essentially unchanged.

Suction noise muffler for internal combustion engine

Abstract: PURPOSE: To reduce the suctinon noise by providing a expansion chamber and a resonance chamber on the suction piping of four cycle engine. COPYRIGHT: (C)1979,JPO&Japio

Internal combustion engine with auxiliary piston for generating turbulence

Abstract: An internal combustion engine is provided with an auxiliary piston reciprocating within an auxiliary chamber for generating turbulence in a gas mixture contained within a main combustion chamber. Forward motion of the auxiliary piston causes the injection of a gas into the main combustion chamber through a communicating passageway when the main piston approaches top dead center of the compression stroke.

Cetane Rating and Load Effects on Combustion Noise in Diesel Engines

Abstract: Experiments have been performed on a single cylinder air-cooled direct injection four stroke Diesel engine to determine the connection between combustion randomness and radiated noise. The tests reported have carried the engine to its maximum fuel flow condition and investigated the effects of Cetane rating. The tests have conclusively demonstrated that a substantial anount of the radiated noise is causally related to the randomness (turbulence) of the combustion process and not the mean pressure-time history. However, the higher the load, the less the effect of the randomness on total noise output.

Two-cycle internal combustion engines with scavenger means

Abstract: A fuel scavenger for a two-cylinder, two-cycle horizontal upper and under type internal combustion engine. The engine has a crankcase with a revolving crankshaft which is turned by the reciprocating movement of a piston in each of the cylinders. A carburetor supplies air/fuel mixture to the crankcase via respective intake passages and reed valves. A fuel catcher is located in each crankcase, substantially shielded from the scouring action of air/fuel mixture impelled by the crankshaft, and the fuel catcher of each cylinder is connected to the intake passage of the other cylinder via a respective check valve.

Variable chamber diesel engine

Abstract: A two-cycle diesel engine comprising a diesel head and a combustion chamber whose size is variable upon movement of a flexible fluorocarbon membrane The diesel engine has an engine cylinder in which a reciprocating piston is disposed The combustion chamber is positioned above the piston and bounded on top by the membrane Since fuel ignition occurs because of the heat from the compression of air in the combustion chamber, the rate of firing of the engine can be altered by changing the chamber's size This is accomplished by a flexing and unflexing movement of the membrane which is selectively controlled by a contra piston and screw mounted in the diesel head above the membrane

Testing method for a reciprocating internal combustion engine

Abstract: A testing method for a reciprocating internal combustion engine, in which values of the angular velocity are measured over an angular range of approximately 32° about the top dead center while the engine is running under its own power and at a predetermined speed, and are compared with values of the angular velocity for an entire revolution, and in which the ratio so determined is compared with a similar angular velocity ratio present for an engine of the same engine type at the same speed and with the engine running perfectly.

Governor control for an internal combustion engine

Abstract: A governor control for an internal combustion engine of the type wherein air is blown in the operation of the engine to move an air vane connected with the throttle plate for throttling the engine. An operator-controlled handle is movably mounted and interconnects with the air vane through a spring and a flexible cable, all for placing spring tension on the air vane to resist the blowing by the engine and thus govern the engine's speed. A movable stop member is operative on the handle and is spring urged so that the handle can be set in normal engine speed positions and thus cause the engine to run slow or fast, and the handle can also be set in an overriding and spring-urged position to cause the engine to run faster and the spring will automatically return the handle to the fast engine speed position when the operator releases the handle.

Piston and ring for reducing HC emissions

Abstract: An internal combustion engine is provided with pistons having openings connecting the space behind one of the piston rings with the crankcase during certain portions of the operating cycle of the engine. This is accomplished by the use of a differential pressure control valve that vents the unburned hydrocarbons trapped behind the compression ring to the crankcase during periods when the pressure in the combustion chamber is at the lower values during the internal combustion engine operating cycle. These unburned hydrocarbons are, therefore, directed into the crankcase of the engine rather than being permitted to leak back into the combustion chamber and to be discharged into the atmosphere during the exhaust stroke of the engine.

Four-stroke engine camshaft with stepped cams - starts engine as two stroke system and has three steps for different cam characteristics

Abstract: The four stroke reciprocating piston engine has camshaft operated valves and the camshaft has cams each with three steps for a valve. The camshaft is moved axially for bringing a particular cam step in contact with a valve push rod. This system ensures good engine starting, warming up and running characteristics. The internal combustion engine has exhaust gas flow brakes with a throttling flap (14) situated in exhaust gas pipe (13). The camshaft (3) has normal operating cams for the engine and it also ensures a delayed opening period and early closing of the inlet valve for engine starting. In addition the cams operate the gas inlet and outlet valves as in a two stroke engine for starting. Subsequently on reaching the starting speed, the camshaft is moved into position with delayed opening and early closing of inlet valves if outlet temperatures and engine are cold. Finally the camshaft is shifted into regular operating position.

V-type or horizontally opposed type four cycle engine for motorcycle

Abstract: PURPOSE: To reduce the width of a V-type or horizontally opposed type four cycle engine for motor cycle by utilizing a recess in the cylinder. CONSTITUTION: An engine comprises a speed changer housing 20 to the top of which the lower end of an cylinder block 10 is fixed and an oil pan 30. A recess is formed on the side of a right forward cylinder 101 and of a left rear cylinder 102 respectively in which linking mechanisms 61 and 62 to link cam drive mechanisms 51 and 52 to a crank shaft 40 are installed whereby the width of the engine is reduced as compared with conventional engine which has such linking mechanisms 61 and 62 installed on the same side of the cylinder COPYRIGHT: (C)1979,JPO&Japio

Process and device for determining the quantity of air inducted by an internal combustion engine

Abstract: The quantity of air inducted in a four cylinder Otto engine with fuel injection and an inlet throttle for each cylinder is determined by indirect measurement, unaffected by atmospheric pressure variations. The induction air pressure is measured by a transducer located between one of the throttles and its associated cylinder inlet valve, and the pressure is sampled, using an electronic gating system responsive to engine speed, within a precisely defined range (preferably 15°-25° after bottom dead center) of engine crankshaft angle.

Fuel system for IC engines - has water alcohol mixture injected after ignition has taken place

Abstract: A conventional four stroke engine is provided with an additional fuel injector (28) in the cylinder head, fitted as close as possible to the spark plug or existing injector. The auxiliary injector is fed from a fuel pump driven via the valve cam shaft. The fuel pump is connected to a tank containing either pure water, a water alcohol mixture or a water oil emulsion. The auxiliary fuel pump is timed to give a water fuel mixture injection before piston t.d.c. and 5 to 19 deg. after ignition has taken place. The injection timing is automatically advanced and retarded in conjunction with the ignition timing.

Secondary air feed control device of an internal combustion engine

Abstract: Disclosed is an internal combustion engine comprising a carburetor and a secondary air feed control valve for feeding secondary air into the exhaust system of the engine from the air pump driven by the engines. The engine further comprises a temperature detector for indicating whether the warm-up of the engine is completed, and a gear position detector for indicating whether the shift gear of the transmission of the engine is in the top gear position. A relatively lean air-fuel mixture is fed into the cylinder of the engine and a relatively small amount of secondary air is fed into the exhaust system when the shift gear of the transmission is in the top gear position after completion of the warm-up of the engine.

Two-stroke engine and direct thrust piston

Abstract: A cylinder with cross inlet and exhaust ports contains a combination piston and rod having on its piston end a piston head or face and slidably attached sealing sleeve, and its other end is rotatable via a rod bearing attached to a crankshaft. The rotational motion of the rod with the crankshaft imparts an undulating movement to the piston head during its stroke motion and, in unison with the slidably attached sealing sleeve, effects a sequence wherein the exhaust ports open ahead of the inlet and close before the inlet closes.

Fuel feeding method and its apparatus for internal combustion engine

Abstract: PURPOSE: To carry out proper feeding and interception of fuel corresponding to the operation state of the engine by calculating the crank angle of the internal combustion engine. COPYRIGHT: (C)1978,JPO&Japio

Method and means for increasing the mean efficiency of an Otto cycle engine

Abstract: For improving the efficiency of an Otto cycle engine operating under varying loads, an opposing piston is provided above the driving piston in each cylinder and is controlled in accordance with the inlet manifold depression so as to vary the compression ratio and maintain the compression substantially constant with different working loads.

High compression vehicle IC engine - has inlet valve arranged to shut late and small vol. combustion space

Abstract: The otto cycle four stroke engine operating process is particularly for motor vehicles. The inlet valve shuts so late after bottom dead centre that the smaller effective compression stroke gives the desired compression ratio in conjunction with a smaller clearance volume. In the speed range corresponding to maximum torque a quantity of mixture roughly equal to the capacity of the clearance volume can be pumped back through the inlet valve into the inlet manifold. The inlet valve can be arranged to shut at up to 90 degrees after bottom dead centre. Fuel can be injected continuously via a nozzle in the inlet manifold, aimed at the inlet valve.