RU2231657C2 - Two-stroke internal combustion engine - Google Patents

Abstract

FIELD: mechanical engineering; internal combustion engines.

SUBSTANCE: invention can be used in two-stroke engines operating on different kinds of fuel such as gasoline, kerosene, alcohol, solar oil. Proposed two-stroke internal combustion engine has cylinder with two exhaust ports, piston connected with crankshaft through connecting rod, two intake channels with valves located in cylinder head, nozzle, combustion chamber formed by piston and cylinder head, and spark plug. Control air pressure sensor and valve control device are installed in cylinder head. Each valve control device has series-mounted and mechanically coupled rocker, rod, pusher, crankshaft with eccentric and spring to return valve into initial position arranged on valve between cylinder head and rocker. Oil in crank chamber case serves to lubricate and cool cylinder walls, piston and parts of crank gear.

EFFECT: improved economy of engine, reduced toxicity of exhaust gases.

2 cl, 4 dwg

Description

The invention relates to mechanical engineering and can be used in push-pull type internal combustion engines operating on various types of fuel (gasoline, kerosene, alcohol, gas, diesel fuel).

Known two-stroke internal combustion engine 2SD-M1 (“Stationary small engine 2SD-M1 and its modifications.” Operation manual RE 37.313.001-76 V / O “Energomashexport” of the USSR, Moscow), having a crank-chamber two-channel purge, gas distribution cylinder-piston group, the working process is completed within two strokes of the piston, i.e. for one crankshaft revolution. The 2SD-M1 engine contains a cylinder with 4 windows: two purge, exhaust and intake, a piston placed inside the cylinder, which is connected by a connecting rod to the crankshaft, a combustion chamber formed by the piston and cylinder head, an spark plug, a carburetor and located under the piston crank chamber with a “dry” crankcase.

A disadvantage of the known device is as follows:

- insufficient optimization of the mixture formation process inherent in any carburetor power system;

- high toxicity of exhaust gases due to the presence of oil in the working mixture, which is added to the fuel to lubricate the walls of the liner and parts of the crank mechanism, which complicates the complete combustion of the fuel, as well as the difficulty of maintaining the optimal composition of the air-fuel mixture (1: 14.7) and low adaptation to various engine operating modes.

The closest in technical essence (prototype) is a two-stroke internal combustion engine containing a cylinder with two exhaust windows, a piston connected by a connecting rod with a crankshaft, two inlet channels with valves located in the cylinder head, a nozzle, a combustion chamber formed by the piston and cylinder head, spark plug (patent for invention of the USSR No. 16483, F 02 B 25/00, 1930).

A disadvantage of the known device is the low efficiency of the engine, since the moment of fuel injection and the dose of injected fuel are not determined, as well as the high toxicity of exhaust gases due to the presence of oil in the working mixture, which is added to the fuel to lubricate the walls of the liner and parts of the crank mechanism, which complicates the complete combustion of fuel, the difficulty of maintaining the optimal composition of the air-fuel mixture (1: 14.7) and low adaptation to various engine operating modes.

The objective of the invention is to increase engine efficiency and reduce exhaust emissions.

The technical result of the proposed solution is to increase the efficiency of the engine due to the fact that fuel is injected into the combustion chamber when a certain pressure in the combustion chamber is reached, and the dose of fuel injected into the cylinder depends on the amount of air supplied to the cylinder, which ensures the optimum ratio of the working mixture, as well as reducing the toxicity of exhaust gases due to the lack of oil in the working mixture, as well as due to more complete combustion of the working mixture in connection with maintaining we have the optimal mixture formation mode.

An additional technical result is that the introduction of a “wet” crankcase in a two-stroke engine improves the lubrication and cooling of the engine, which increases the reliability and durability of its operation.

To achieve a technical result, a two-stroke internal combustion engine comprises a cylinder with two exhaust windows, a piston connected by a connecting rod with a crankshaft, two inlet channels with valves located in the cylinder head, a nozzle, a combustion chamber formed by the piston and cylinder head, an spark plug, and in the cylinder head there is a control air pressure sensor and a valve control device, each of which contains sequentially and kinematically connected rocker arm, rod, pusher , a counterweight to the crankshaft with an eccentric and a spring returning the valve to its original state, located on the valve between the cylinder head and rocker.

Oil is placed in the crankcase of the crank chamber to lubricate and cool the walls of the cylinder, piston, and parts of the crank mechanism.

The invention is illustrated by drawings, in which Fig. 1 schematically shows the claimed engine with the piston position near top dead center (TDC) (left) and near bottom dead center (BDC) (right), in Fig.2 - valve control device, in Fig. 3 is a diagram of a control air pressure sensor; FIG. 4 is a diagram explaining the operation of an engine prototype 2SD-M1.

The Kamenev’s two-stroke internal combustion engine (ICE) contains a cylinder 1, two exhaust ports 2, a piston 3, a connecting rod 4, a crankshaft with eccentric plates on counterweights 5, a combustion chamber 6, a cylinder head 7, a crank chamber 8 with a “wet” crankcase, spark plug 9, inlet channels 10, valve 11, nozzle 12, control air pressure sensor 13.

The valve control device comprises a spring 14, a rocker 15, an adjusting screw 16, a rod 17, a pusher 18, an emphasis 19, an eccentric plate 20 profile, which is located on the counterweight of the crankshaft.

The above version of the control air pressure sensor includes a housing 21, a valve stem 22, a thrust washer 23, a sealing collar 24, a nut 25, a shaped washer 26, a spring 27, an adjusting nut 28, a microswitch 29, a cylinder head 30.

A two-stroke internal combustion engine operates as follows. When the piston moves in the cylinder from TDC to BDC, after ignition of the working mixture, a working stroke occurs in the combustion chamber. When the piston 3 approaches the BDC, the exhaust ports 2 open and exhaust gas is released. At this time, the crankshaft 5 is rotated so that its counterweights are at the top. On the counterweights, wear-resistant eccentric plates 20 are attached, which come in contact with the pusher 18, lifting it and the rod 17, which in turn interacts with the rocker 15. The rocker 15, overcoming the pressure of the spring 14, opens the inlet valve 11 and from the autonomous supercharger into the cylinder 1 clean air is supplied, which fills the cylinder 1 and pushes the remaining exhaust gas through the exhaust ports 2. The eccentric 20 of the crankshaft comes off the pusher 18, the intake valve 11 closes and the piston 3 begins to compress zduh. The start and end times of the intake valve actuation sets the profile of the eccentric plate 20. A control air pressure sensor 13 is installed in the cylinder head 7. When the pressure in the cylinder 1 reaches the control pressure (for example, 2 kgf / cm ² ), which is set by the adjusting nut 28, the valve the rod 22, overcoming the pressure of the spring 27, moves up and closes, closing the contacts of the micro switch 29, which is a signal for instructing the nozzle 12 to start fuel injection into the cylinder 1. Changing the air pressure from the supercharger, automatically the fuel injection time will also change, which means that the optimal ratio of the working mixture at various engine operating modes will be maintained. When the piston 3 approaches the TDC, the nozzle 12 is turned off and the mixture is ignited by an electric spark from the spark plug 9. The stroke of the piston 3 begins and the cycle repeats. The valve stem 22 remains closed until the stroke and exhaust are completed. After the pressure drop in the cylinder 1 below the control valve-valve 22 opens, the contacts of the microswitch 29 open.

Depending on the design (the degree of air compression, pressure and the method of fuel injection into the cylinder), the engine can operate both when the ignition mixture is ignited from the spark plug (work on gasoline, kerosene, alcohol, gas), and when the mixture is self-igniting (working on diesel fuel) .

The use of an eccentric located on the counterweight of the crankshaft in the engine, unlike the classic version of the gas distribution mechanism, makes it possible to abandon the camshaft and drive gears, which greatly simplifies the gas distribution mechanism and increases the reliability and durability of the engine as a whole.

Claims (2)

1. A two-stroke internal combustion engine comprising a cylinder with two exhaust ports, a piston connected by a connecting rod with a crankshaft, two inlet channels with valves located in the cylinder head, a nozzle, a combustion chamber formed by the piston and cylinder head, an spark plug, characterized the fact that a control air pressure sensor and a valve control device are installed in the cylinder head, each of which contains sequentially and kinematically connected rocker arm, rod, pusher, counterweight count a crankshaft with an eccentric and a spring returning the valve to its original state, located on the valve between the cylinder head and the beam. 2. The engine according to claim 1, characterized in that oil is placed in the crankcase of the crank chamber to lubricate and cool the walls of the cylinder, piston and parts of the crank mechanism.

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