EA025246B1 - Method of operation of a four-stroke internal combustion engine - Google Patents

Abstract

The invention is related to thermal engines and can be used in internal combustion engines working on light fuel. The objective of the invention is higher economical efficiency of internal combustion engines and lower toxicity of exhaust gases in idling or under partial loads close to idling. Said objective is attained by provision of a method of a four-stroke internal combustion engine operation in idling or at low loads, wherein fuel feed to a part of cylinders is stopped, and deactivated cylinders are filled with fresh air; in four-stroke engines equipped with an electronic feed system with injection of light fuel, during the engine operation in idling and at partial loads close to idling, fuel injection is performed not every time as the cylinder is filled with fresh air but with skipping each second suction of working charge, e.g., in even-numbered operating cycles, while fuel feed in odd operating cycles is fully excluded, therefore, one operating cycle is performed during four rotations of the crankshaft according to eight-stroke operation principle. The electronic fuel feed control unit comprises two independent engine feed control systems: 1 - the main fuel feed control system performs electronic control of fuel feed nozzles for even operating cycles and of the ignition advance angle for all operating cycles; 2 - the interruptible fuel feed control system feeds fuel for odd operating cycles; for a multi-cylinder engine, the order of nozzles activation in each control system is designed in accordance of the order of operation of the given engine, e.g., in a four-cylinder engine with the cylinder firing order 1 3 4 2, the order of nozzles activation by the main feed system is as follows: 1-4 -- 3-2, and the order of nozzles activation by the interruptible fuel feed control system feeds fuel for odd operating cycles corresponds to -3-2 1-4-. Deactivation and activation of the electronic interruptible fuel feed control system for odd operating cycles is performed automatically, the fuel feed system deactivating as rarefaction near inlet valve reaches the range of 0.03-0.06 MPa, and activating with full opening of the throttle. The technical result of using the invention is an increase in effective work from fuel burning in the internal combustion engine, lower toxicity of exhaust gases and lower pumping losses in the fuel inlet process, which will allow development of energy-efficient, environment-friendly engines providing complete combustion of fuel to final combustion products harmless for the environment in all modes of engine operation.

Description

The invention relates to the field of internal combustion engines, in particular, to methods for operating internal combustion engines operating on light fuel.

A known method of operation of a two-stroke internal combustion engine with an adjustable combustion chamber, depending on the implementation of the duty cycle. At the same time, under low load conditions, the engine starts to operate as a four-stroke cycle with one working cycle for four piston strokes. The volume of the combustion chamber is reduced. With an increase in load, the engine switches to two-stroke operation, and the volume of the combustion chamber increases. The duty cycle control device comprises a first engine control unit in a push-pull mode, a second unit controlling an engine in a four-stroke mode; unit for switching between the first and second control units [1].

With this method of operation of an internal combustion engine, exhaust emissions are reduced. However, the implementation of this method for a four-stroke internal combustion engine is not proposed, which is an essential distinguishing feature of novelty.

There is a known method of operation of a four-stroke internal combustion engine, which consists in the fact that when operating at idle and low loads, the fuel supply to a part of the cylinders is cut off, the disconnected cylinders are filled with fresh air, it is compressed and bypassed by means of bypass valves into working cylinders, while increasing last cyclic fuel supply. The disconnected cylinders are put into a push-pull compressor mode. As a result, in the disconnected cylinders, the stroke and stroke are transferred to the processes of filling and compressing fresh air, which also increases the air charge in the working cylinders. When all cylinders are turned on, the bypass valves are closed, and the cylinders operate as usual [2].

In the known method of operation of a four-stroke internal combustion engine, an increase in efficiency is achieved by transferring part of the working cylinders to a two-stroke compressor mode. The remaining working cylinders begin to work with greater power, as a result of this, the thermal tension of the parts of the working cylinders increases, which adversely affects the mechanical efficiency of the engine and its durability. It is obvious that only when the engine is operating under partial load conditions it is rational to alternate the working and compressor cycles in each cylinder, thereby reducing the thermal stress of the engine and reducing the heat loss from fuel combustion due to cooling of the engine parts during the compressor cycle.

According to the known method of operation of a heat engine, engine power with the injection of light fuel is regulated using a throttle valve, which changes the amount of air entering the engine cylinders, and the composition of the mixture depends on the mass of fuel injected by the fuel supply equipment. It should be noted that a modern car under normal operating conditions operates at full load no more than 10-15% of the total driving time. Full throttles are used relatively rarely, only when the car is moving with acceleration or when climbing large climbs, and in the vast majority of cases the car is operated with partial loads associated with small throttle openings. When approaching idle, the throttle is closed, as a result of which a significant vacuum is generated in the intake manifold, the suction pressure decreases, and therefore, the amount of mixture freshly entering the cylinders decreases with an almost constant amount of residual gases; as a result, their relative amount in the mixture increases sharply, reaching a maximum at idle speed of the engine. The ignition and combustion conditions of such a mixture are particularly unfavorable due to a decrease in the amount of oxygen in the mixture and the presence of a significant amount of inert residual gases in the combustion chamber. Any delay in the combustion process leads to an unsatisfactory heat balance and, consequently, to a decrease in both efficiency and engine power. Under operating conditions, every effort must be made to ensure that all fuel burns when the piston is near top dead center. When the engine is idling, due to a decrease in the working pressure in the cylinders and at relatively low slightly varying temperatures, the percentage of dissociating gases increases, but at the same time, the relative heat loss to the cooling water increases, which ultimately also reduces the efficiency indicator. The stated provisions allow us to state that the presence of significant amounts of residual gases in the working mixture slows down the combustion process, and in two-stroke engines they sometimes cause the mixture to ignite. To obtain a sufficiently fast combustion of the working mixture at low loads, it is necessary to enrich it, which leads to an increase in fuel consumption and the harmfulness of exhaust gases. The result of unsatisfactory running cycles at idle and near idle is an increase in specific fuel consumption and an increase in the amount of toxic components in exhaust gases. At the same time, air flow throttling is a completely useless job that increases pumping losses during gas exchange in working cylinders.

The objective of the invention is to increase the efficiency of the internal combustion engine and reduce the toxicity of exhaust gases when the engine is idling and partial loads close to idling.

The specified technical problem is solved by the fact that, according to the method of operation of a four-stroke internal combustion engine when operating at idle and low loads, the flow is stopped

- 1 025246 fuel to a part of the cylinders and fill the disconnected cylinders with fresh air, in four-stroke engines equipped with an electronic power system with injection of light fuel, when the engine is idling and partial loads close to idle, fuel is not injected every time when filling cylinder with fresh air, and with the passage of every second suction of the working charge, for example, in even duty cycles, while the fuel supply for odd duty cycles is completely eliminated, as a result of which one working cycle is carried out for four revolutions of the crankshaft according to an eight-stroke principle of operation. The electronic fuel supply control unit includes two independent engine power control systems: 1 - the main power control system electronically controls the fuel nozzles for even duty cycles and the ignition timing for all duty cycles; 2 - a switchable electronic fuel supply control system delivers fuel according to odd duty cycles, while for a multi-cylinder engine the order of switching on the nozzles in each control system is calculated depending on the operation of this engine, for example, in a four-cylinder engine with the order of operation of the cylinders 1342 the order of switching on of the main nozzles the power supply system is as follows: 1-4 - 3-2, and the order of turning on the nozzles of the disconnected electronic fuel management system corresponds to -3-21-4-. Disabling and turning on the electronic fuel supply control system for odd cycles is carried out automatically, and the fuel supply system is turned off when the vacuum near the intake valves reaches 0.03-0.06 MPa, and turns on when the throttle is fully open.

The technical result when using the proposed solutions is to increase the useful work from the combustion of fuel in an internal combustion engine, to reduce the toxicity of exhaust gases and to reduce pumping losses during the intake process, which will allow the development of economical, environmentally friendly engines that ensure complete combustion of fuel to final, environmentally friendly , combustion products at all engine operating modes.

In FIG. 1 shows a diagram of a four-stroke internal combustion engine operating according to the proposed method.

The internal combustion engine itself (Fig. 1) does not differ from the traditional one and contains at least one cylinder 1 with a piston 2 kinematically connected to the crankshaft 3, an inlet valve 4, an exhaust valve 5, and a spark plug 6. A block head is installed in the inlet channel electromagnetic fuel injector 7. Fuel from the tank to the electromagnetic nozzles 7 is supplied by an electric pump 8. Organization of the processes of supply, ignition and combustion of fuel in the cylinder 1 of the engine is carried out under the control of a control system. The volumetric fuel supply depends on the duration of the opening of the valve of the electromagnetic nozzle 7. Pulses of variable duration supplied through the wires to the coil of the valve of the nozzle 7 are formed in the electronic units 9 and 10. The electronic control unit 9 supplies electric pulses to the electrically controlled nozzles 7 for even working cycles . The control unit 10 is responsible for supplying pulses to the electromagnetic nozzles 7 over odd duty cycles. The sensors monitor various engine parameters that affect the duration and timing of the fuel pulse. The turn-on time of the electromagnetic nozzle increases with decreasing temperature and is monitored by the temperature sensor 11. The temperature switch 12 blocks the pressure sensor 13, preventing the electronic control unit 10 from being disconnected from the supply network at idle coolant temperatures. The amount of air entering the engine cylinders is regulated by the throttle 14. The position of the throttle when the engine is running is controlled by the sensor 15.

The method of operation is as follows. When starting a cold engine, both electronic control units 9 and 10 form the necessary fuel supply pulses for even and odd duty cycles. As the engine warms up, the pulse duration is adjusted in the electronic units 9 and 10 depending on the temperature of the coolant measured by the temperature sensor 11. At the rated power of the heated engine, as well as at start-up, the electronic control units 9 and 10 send their pulses through the wires to the coil electromagnetic nozzle 7. At full and close loads, the throttle valve 14 is open, which ensures good cleaning of the combustion chamber from exhaust gases and creates the necessary conditions for self-confidence ennogo ignition and complete combustion of the combustible mixture. Fuel burns to the end, environmentally friendly combustion products. As the load decreases and the approach to idling, the throttle valve 14 is closed, the pressure in the intake manifold decreases, and when the vacuum reaches 0.03-0.06 MPa, the pressure sensor 13 disconnects the electronic control unit 10 from the power, due to the supply of fuel to the engine cylinders on odd duty cycles ceases. It should be noted that on a cold engine, the temperature switch 12 blocks the pressure sensor 13, as a result of which the electronic control unit 10 continues to send pulses to the electromagnetic nozzles 7 on odd duty cycles in all engine operating modes. In a warm engine, the pressure sensor 13 works and disconnects the electronic control unit 10 from power when discharged in the intake manifold of 0.03-0.06 MPa. At the same time, the main electronic control unit 9 delivers electrical pulses to the electrically controlled nozzles 7 for even working

- 2 025246 cycles, as a result of which fuel is injected into the working cylinders 1 only in even working cycles. Consequently, at idle and partial loads close to idle, fresh air with a large amount of residual gas is compressed instead of the working mixture in odd duty cycles in the engine cylinders. As a result of compression of clean air by mixing it with residual gases and contact with highly heated engine parts (exhaust valves, spark plugs, combustion chamber walls and pistons), the temperature and pressure of the gases in the cylinder 1 increase. At this time, the temperature of the heated engine parts decreases, which positively affects their work and thermal condition of the engine. When the piston 2 moves back to bottom dead center, the compressed and heated mixture of clean air with residual gases expands, and the stored energy is transformed into mechanical work. In the process of expansion, the temperature of the engine parts continues to decrease, and the thermal energy is transferred to the heated gas. The work obtained in the process of expanding heated air without burning fuel is positive and exceeds the work spent on compressing fresh air. The exhaust gas leaves the cylinder 1 of the engine at the next stroke of the piston 2 to the top dead center, after which the exhaust valve 5 closes. It should be noted that the presence of a large amount of free oxygen in the composition of the exhaust gases entering the exhaust system at their relatively low temperature increases the efficiency of using catalytic converters. The service life of the latter is increased, and at all operating modes of the internal combustion engine, effective neutralization of all major toxic components to the final, environmentally friendly combustion products is ensured. Then begins an even work cycle; the piston 2 moves to bottom dead center, the working cylinder 1 is filled with a combustible mixture, including a small amount of inert residual gases from the previous working cycle. Obviously, it is the combustion pass for odd duty cycles that provides the composition of the working mixture with a low content of inert gases, since the residual gases from the odd duty cycles consist of fresh air and only partially of the combustion products. As a result, the coefficient of residual gases when the engine is idling and partial loads close to idle decreases sharply, and the coefficient of excess air rises, which favorably affects the combustion process and economic performance of the engine. When the car is moving with acceleration, the throttle valve is opened, the throttle position sensor 15 by means of the controller turns on the power of the electronic control unit 10 and the fuel mixture begins to flow into the engine cylinders, both in odd and even odd duty cycles, which, accordingly, leads to an increase in power engine. Therefore, when the engine is operating according to the proposed method, the engine running at full and close to full loads does not differ from the way the four-stroke internal combustion engine works with an electronic power system and injecting light fuel, and when the engine is idling and partial loads according to the proposed method, the engine runs with a duty cycle consisting of eight cycles (eight-stroke) and double cleaning of the exhaust gas cylinders. It should be noted that for a multi-cylinder engine, the order of switching on the nozzles in each control system is calculated taking into account the achievement of the maximum possible uniform torque obtained on the crankshaft of the engine, and depending on the operation of this engine. For example, for a four-cylinder engine with a cylinder working order of 1342, the order of turning on the nozzles of the main power system is as follows: 1-4 - 3-2, and the order of turning on the nozzles by the switch-off electronic fuel management system corresponds to -321-4-. In a four-stroke eight-cylinder engine with an operating order of cylinders 13758624, the following order of switching on the nozzles of the main power system is recommended, which ensures uniform rotation in all modes and loads: 1-7-8-2 - 3-5-6-4, and the order of switching on the nozzles is switched off by electronic fuel management system corresponds to -3-5-6-4 1-7-8-2-. Thus, the proposed method of engine idling and partial loads close to idling improves the conditions of the combustion process, namely, to increase the air charge in the working mixture by re-cleaning the cylinders from exhaust gases, which will ensure timely ignition, speed and complete combustion of the working mixture will significantly reduce the content of toxic components in the exhaust gases and will positively affect the use of heat when the engine is operating at partial load x The economic and social effect of using the proposed method is to increase the efficiency and reduce the harmfulness of the exhaust gases of a car engine. Sources of information taken into account:

1. Application, ΙΡ 4244603В2, Р02В 75/00, 2004

2. Copyright certificate of the USSR 8I 1036947, Ρ02Ό 17/02, 1982

Claims (1)

CLAIM The method of controlling the operation of an automobile four-stroke internal combustion engine, comprising at least one cylinder with a piston, kinematically connected with the crankshaft, an electromagnetic fuel supply nozzle installed in the intake channel of the cylinder, and two electronic fuel control units — the first main electronic control unit is configured with - 3 025246 possibility of supplying electric pulses to the electromagnetic fuel injection nozzle in even work cycles on all modes of operation of the internal combustion engine, and the second electronic control unit is configured to apply electric pulses to the electromagnetic fuel delivery nozzle in odd operating cycles, at which electric impulses are delivered to the electromagnetic fuel injection nozzle from two electronic fuel supply control units simultaneously when starting the cold engine of the internal combustion or when the internal combustion engine is running at full power, injecting fuel into the cylinder at each operating cycle, and disconnecting the second electronic fuel supply control unit when the internal combustion engine is operating at idle and partial loads close to idle, excluding fuel injection into the cylinder through its odd duty cycles, and fuel is injected into the cylinder only through even duty cycles by applying electrical pulses to the electromagnetic fuel injection nozzle from of the second electronic fuel supply control unit and electrical impulses to the electromagnetic fuel injection nozzle for odd duty cycles are automatically carried out while reducing the load on the internal combustion engine and achieving an inlet discharge of 0.030.06 MPa, include a second electronic control unit for fuel supply and supply of electric pulses to the electromagnetic nozzle for fuel supply through odd duty cycles when the throttle valve is fully opened, and for a four-cylinder automobile internal combustion engine with the order of operation of the cylinders (1 3 4 2), electric impulses are supplied to the electromagnetic injectors through even running cycles by the first main electronic fuel control unit through even running cycles in order (1 - 4 - - 3 - 2), and the second electronic control unit of fuel supply for odd duty cycles in the following order (- 3 - 2 1 - 4 -), and for an eight-cylinder internal combustion engine with the order of operation ndrov (1 3 7 5 8 6 2 4) apply electric pulses to the electromagnetic nozzles by the first electronic fuel supply control unit on even work cycles in order (1 - 7 - 8 - 2 - - 3 - 5 - 6 - 4), and the second electronic control unit of fuel supply in odd duty cycles in the following order (- 3 - 5 - 6 - 4 1 - 7 - 8 2 -).