RU2635169C1 - Gas exchange system of internal combustion engine cut-off cylinders - Google Patents

Abstract

FIELD: engine devices and pumps.

SUBSTANCE: gas exchange system of internal combustion engine cut-off cylinders comprises a gas exchanger (10), which inner cavity has at least one two-position control valve. The inner cavity of the gas exchanger is permanently connected in the lower part with supply outlet branch pipes of the cut-off cylinders. With a discharge branch pipe connected to a catalytic collector (9), the inner cavity of the gas exchanger is connected with the possibility of closing the connection. In the upper part of the gas exchanger inner cavity there is an opening communicating with inlet of the gas exchange channel which can be closed by the two-position valve. An outlet opening of the gas exchange channel is connected to insulated volume formed in a receiver body (1) due to the presence of additional internal walls provided with a movable cover. The outlet of the isolated volume is connected to the inlet branch pipes of the cut-off cylinders so as to form a closed gas exchange circuit (21) of the disconnected cylinders.

EFFECT: reduction of throttle losses without increase of friction losses in movable joints of cylinder parts.

2 cl, 9 dwg

Description

The invention relates to engine building, and in particular to the regulation of gas exchange of disconnected cylinders of an internal combustion engine to increase the efficiency and environmental friendliness of engines.

An internal combustion engine is used as a drive for automobile vehicles. In the framework of the present description, the term "internal combustion engine" combines gasoline engines.

When designing an internal combustion engine, the principal goal is to reduce fuel consumption, while the main task is to increase the overall efficiency.

The problem of providing low fuel consumption and, thus, high efficiency is especially acute when using gasoline engines with an Otto cycle, i.e. spark ignition engines. This problem is due to the principle of operation of such an engine. The load control is usually carried out using a throttle located in the intake system. By turning the throttle, you can adjust the intake air pressure downstream of the throttle. The lower the degree of throttle opening, i.e. the more it blocks the flow in the intake system, the greater the loss of pressure of the intake air when passing through the throttle, and the lower the pressure of the intake air downstream of the throttle and upstream of the inlet to at least two cylinders, i.e. e. two combustion chambers. Thus, with a constant volume of the combustion chamber, the mass air flow, i.e. amount of mixture. This also explains why quantitative control turns out to be disadvantageous precisely at partial load: light loads require strong throttling and pressure reduction in the intake system, as a result of which, when the load is reduced and the throttling increases, the losses increase when the working mixture is fed into the cylinder.

To reduce such losses, various strategies have been developed to reduce the throttle rate of the gasoline engine with the Otto cycle.

One way to reduce the throttle rate of a gasoline engine may be, for example, to use a gasoline engine with direct injection. Direct fuel injection is a suitable means for implementing stepwise loading of the combustion chamber. Direct injection of fuel into the combustion chambers allows within certain limits to carry out high-quality regulation of the mixture in a gasoline engine. The formation of the mixture is carried out by direct injection of fuel into the air in the cylinders, and not by external mixture formation, in which the fuel in the intake system is fed into the intake air.

Another possibility of optimizing the combustion process in a gasoline engine is to use at least a partially adjustable valve mechanism. Unlike traditional valve mechanisms, in which the valve stroke and valve timing are constant, these parameters affecting the combustion process and fuel consumption can be varied to one degree or another using valve mechanisms. In cases where the closing time of the intake valve and the stroke of the intake valve can vary, it is only due to this that it is possible to control without throttling and, thus, without load loss. The mixture or charge air entering the combustion chamber during the inlet is not controlled by the throttle valve, but by the stroke of the inlet valve and its opening time. However, variable valve actuators are very expensive and therefore rarely used in serial production.

Another way to reduce the throttle rate of a gasoline engine is to turn off the cylinder, i.e. shutdown of individual cylinders in certain load ranges. The efficiency of a gasoline engine in partial load mode can be improved (i.e. increased) by such a partial shutdown, since shutting down one cylinder of a multi-cylinder internal combustion engine with constant engine power increases the load on the remaining working cylinders. Therefore, the throttle can or should open to supply the right amount of air to these cylinders, resulting in a reduction in the throttle level of the engine. The cylinders that are in constant operation operate during partial shutdown in the high-load mode, in which the specific fuel consumption is lower. The load range shifts toward higher values.

Moreover, due to the large volumes of the supplied air or air mixture, the cylinders operating in the partial shutdown mode have improved mixture formation.

Other advantages in terms of efficiency are that a disabled cylinder due to lack of combustion does not create heat loss by heat transfer from the gaseous products of combustion to the walls of the combustion chamber.

Cylinder shutdown systems, which are capable of shutting off several cylinders in some engine operation modes to save fuel and reduce harmful emissions into the atmosphere, are some of the fastest growing technologies.

In normal city driving, a car typically uses only 30 percent of its maximum engine power. In this case, the throttle is almost closed, and the engine is forced to do work to let in a fresh portion of air. This leads to an increase in so-called pumping losses. In large engines, under such conditions, a significant decrease in cylinder pressure also occurs, i.e. fuel is used inefficiently. Turning off some cylinders can reduce the amount of fuel consumed, reduce pumping losses and increase the pressure in the working cylinders. As a result, fuel economy can range from 8 to 25 percent. It should be noted that the use of such systems is especially effective in engines with many cylinders and a large volume.

Cylinders are deactivated by closing the intake and exhaust valves for a particular cylinder. When both valves are closed, an “air spring” effect is created due to the exhaust gases remaining in the cylinder. Compression and decompression of these gases have an equalizing effect - in general, there is practically no additional load on the engine. In modern generations of cylinder shut-off systems, the fuel supply to the deactivated cylinder is turned off, the transition between normal engine operation and deactivation is smoothed out by changing the ignition timing, valve timing, and throttle position. Thus, the shutdown of part of the cylinders at partial load can be compared with the temporary installation of a smaller engine. At the same time, it remains possible at any time to get all the power of a large engine, unlike other systems designed to increase the efficiency and environmental friendliness of the engine.

Deactivation of the cylinders occurs in those engine operating modes when only a small part of the engine power is required, for example, while maintaining the cruising speed of the car.

When you turn off part of the cylinders, the throttle opens more widely, which helps to reduce pumping losses. It also reduces the energy spent on turning the camshaft, and the cooling system losses are reduced. The mechanical components needed to turn off the cylinders are simple. The systems of all three manufacturers in question use computer-controlled solenoids to move the rods in the valve followers (DaimlerChrysler and GM systems) or in half of the rocker arms (Honda). Honda's Variable Cylinder Management (VCM) is a variation of its proprietary variable valve timing system (VTEC); structurally, the VCM system is based on the VTEC variable valve timing system. The basis of the system is rocker arms interacting with cams of various shapes. If necessary, the rocker arms are switched on or off from work by a locking mechanism (lock).

When the cylinders are deactivated, the electronic engine control unit examines in detail the indicators of the temperature of the coolant, vehicle speed, engine load, etc. When the cylinder is turned off, not only the intake and exhaust valves are interrupted, but also the ignition and fuel supply.

Deactivation takes about 40 milliseconds. It occurs immediately after the piston stroke, the cylinder is filled with exhaust gases and an “air spring” is formed.

The economy of the engine is affected not only by throttle losses, but also by friction losses in the movable joints of engine parts, which are determined by the inlet pressure, the higher this pressure, the higher the pressure inside the cylinder during compression and expansion cycles, respectively, the higher the friction loss. After the intake and exhaust valves are turned off from work, the pressure of the gas forces on the piston in the cylinders to be switched off does not depend on the pressure change in the intake receiver.

With increasing pressure at the inlet to the cylinder, throttle losses decrease, and friction losses increase, on the contrary. This reduces the efficiency of turning off the cylinders using the described valves.

Known systems for controlling an internal combustion engine containing at least two groups of disconnectable and non-disconnectable cylinders connected by inlet and outlet nozzles to intake and exhaust manifolds, a fuel shut-off mechanism to a group of disconnectable cylinders, and air supply control valves from this group to a group of non-disconnectable cylinders (analogue - application JP No. 54 - 17889, class 51E6, 1979).

The disadvantage of the invention is that the presence of separate disconnectable and non-disconnectable cylinders allows to obtain the most economical operation of the engine in only one narrow range of loads, at which the economy of non-disconnectable cylinders is greatest.

A known internal combustion engine control system comprising at least two groups of disconnectable and non-disconnectable cylinders connected by inlet and outlet nozzles to intake and exhaust manifolds, a fuel shutoff mechanism to a group of disconnectable cylinders and air supply control valves from this group to a group of non-disconnectable cylinders, characterized in that in order to increase engine efficiency in a wide range of partial load and idle modes, intake and exhaust projectors all cylinder groups are combined, respectively, outlet pipes disconnected cylinders are connected to the intake manifold by means of piping and control valves are installed at the inlet to the last (analog - AS USSR №.1036947, IPC 5 F02D 17/02, 1983 YG)

The disadvantage of this solution is the lack of effectiveness in reducing friction losses in the movable joints of engine parts, which allow for fuel economy.

The above analogues do not mention the throttle, which is typical for the design of diesel engines.

In the prior art there are no sufficiently close solutions, and the technical solutions described above cannot be adopted as a prototype.

The technical problem solved by the invention is to expand the arsenal of existing engines by changing the gas exchange system while achieving the effect of reducing throttle losses of the engine, which allows to save fuel.

The technical result from the use of all the essential features of the invention consists in the implementation of the engine equipped with the claimed gas exchange system. This ensures a reduction in throttle losses without increasing friction losses in the movable joints of parts of these cylinders.

The technical problem posed is solved due to the fact that a gas exchange system has been developed for disconnected cylinders of the internal combustion engine, comprising a gas exchanger, the internal cavity of which has at least one on-off controlled valve and is connected at the bottom with the inlet exhaust pipes of the disconnected cylinders constantly and with the outlet a pipe connected to a catalytic manifold, with the possibility of overlapping the connection; in the upper part of the cavity is made, with the possibility of overlapping by a two-position valve, a hole in communication with the inlet of the gas exchange channel, the outlet of which is connected to an insulated volume formed in the receiver's housing due to the presence of additional internal walls equipped with a movable cover; the output of the specified isolated volume is connected to the inlet nozzles of the cylinders to be switched off with the possibility of forming a closed gas exchange circuit of the disconnected cylinders.

The valve control is made in the form of a computer-controlled solenoid.

The combination of these features allows you to effectively reduce the throttle loss of the engine and thereby ensure fuel economy.

FIG. 1 - gas exchanger installed in the flow part of the engine.

FIG. 2 - the position of the valves and the movable cover of the receiver when disabling groups of cylinders.

FIG. 3 - position with all working cylinders.

FIG. 4 - the internal cavity of the gas exchanger connected to the inlet and outlet pipes.

FIG. 5 - the relative position of the inlet and outlet pipes.

FIG. 6 is a general view of a multi-cylinder engine with a gas exchanger.

FIG. 7 - gas exchange circuit.

FIG. 8 - actuator on-off controlled valve using a solenoid.

FIG. 9 is a view of a general view of an engine equipped with a gas exchange system of disconnected cylinders.

In FIG. 1, 2, 3, 4, 5 disconnected cylinders are conditionally not shown. In FIG. 2, 3, the receiver case is not shown conditionally.

Description of the device.

The device includes the following elements, indicated in the drawings by the positions:

1 - receiver housing

2 - the inner walls of the receiver

3 - movable cover

4 - inlet nozzles of disconnected cylinders

5 - on-off controlled valve

6 - gas exchange channel

7 - outlet pipe

8 - inlet exhaust pipe disconnected cylinders

9 - catalytic collector

10 - gas exchanger

11 - the internal cavity of the gas exchanger

12 - hole in the upper part of the internal cavity of the gas exchanger

13 - 1st cylinder

14 - 2nd cylinder

15 - 3rd cylinder

16 - 4th cylinder

17 - cylinder inlet valves

18 - exhaust valves of cylinders

19 - actuator on-off controlled valve with a cam

20 - solenoid actuator on-off controlled valve

21 - closed gas exchange circuit

The gas exchange system of the shut-off cylinders 14, 15 (see Fig. 6) of the internal combustion engine contains a gas exchanger 10. The internal cavity 11 of the gas exchanger 10 is equipped with at least one on-off controlled valve 5 (see Fig. 2 - the valve pressure is shown as an example ) In the lower part, the internal cavity 11 is constantly connected to the inlet exhaust pipes 8 of the disconnected cylinders, and to the discharge pipe 7 connected to the catalytic manifold 9 with the possibility of overlapping the connection. In the upper part of the cavity 11, an opening 12 is made, with the possibility of overlapping by a two-position valve 5, communicating with the inlet of the gas exchange channel 6 (see Fig. 2 - the upper part of the cavity 11 is conditionally not shown in the figure). The outlet of the gas exchange channel 6 is connected to an insulated volume formed in the housing of the receiver 1 due to the presence of additional inner walls 2, equipped with a movable cover 3 mounted for movement relative to the inner walls 2. The output of the specified insulated volume is connected to the inlet pipes 4 of the disconnected cylinders 14, 15. Thus, it is possible to form a closed gas exchange circuit 21 of the disabled cylinders (see Fig. 7).

The actuator of the on-off controlled valve 5 can be made either in the form of a solenoid 20 controlled by a computer (see Fig. 8), or in the form of mechanical devices, as well as the drive of the movable cover 3, which must also be controlled by elements associated with the control computer engine (not shown conditionally)

The housing of the receiver 1 is connected via inlet pipes 4 to the engine cylinders 13, 14, 15, 16 (see Fig. 6).

Description of the operation of the device.

In normal engine operation, the hole 12 in the upper part of the internal cavity 11 of the gas exchanger 10 is closed by a two-position controlled valve 5, and the movable cover 3 is open (see Fig. 3). Due to this, the cavity of the isolated volume is in communication with the internal volume of the receiver and the air-fuel mixture enters into all cylinders through the inlet valves 17, and the exhaust gases (exhaust) are removed through the exhaust valves 18 to the catalytic manifold 9. Cylinders 1 (pos. 13) - 3 (key 15) - 4 (key 16) - 2 (key 14).

When the cylinders 2 (14), 3 (15) are turned off, fuel is no longer supplied to them, however, the valve mechanism is not disconnected from operation, as is traditionally done when the cylinders are turned off. At the same time, an increased amount of fuel is supplied to the cylinders 1, 4 in such a way as to maintain the ratio α (kg of air / kg of fuel) for the normal operation of the catalytic manifold 9, i.e. α≤1. Simultaneously with the fuel supply to the cylinders 2 (14), 3 (15) being turned off, the on-off controlled valve 5 begins to open and the movable cover 3 closes. Closing the movable cover 3 above the inner walls 2 ensures the formation of an isolated volume in the receiver housing 1. After the on-off actuator is fully opened the valve 5 and the complete closure of the movable cover 3 in the receiver, the cylinders 2 (14), 3 (15) are turned off from normal operation, however, gas exchange through the inlet valves 17 and exhaust valves 18 occurs in them. In this case, the exhaust gases pushed out of the cylinders at the last stroke before turning off the fuel supply, and at the next exhaust stroke and fresh air charge without fuel, enter through the inlet pipe 8 of the disconnected cylinders into the internal cavity 11 of the gas exchanger 10.

Since the on-off controlled valves 5 block the exhaust gas outlet into the outlet pipe 7 connected to the catalytic collector 9 when the cylinders are turned off, the exhaust gas is sent to the gas exchange channel 6 through the open hole 12 in the upper part of the internal cavity 11 of the gas exchanger 10. Through the gas exchange channel 6, the exhaust gas enters an isolated volume formed in the housing of the receiver 1 between the additional inner walls 2 and the closed movable cover 3. Further from the insulated volume of the exhaust gas through the inlet pipes 4 and inlet valves 17 into cylinders 2 (14), 3 (15). Thus, gases, mainly consisting of air mixed with exhaust gas, circulate through a closed gas exchange circuit 21 of the disconnected cylinders.

The reduction of throttle losses in the working cylinders 1 (pos. 13), 4 (pos. 16) occurs due to the wider opening of the throttle when the second pair of cylinders 2 (14), 3 (15) is disconnected from the duty cycle. The reduction of throttle losses in switchable cylinders 2 (14), 3 (15) occurs due to the fact that gases circulate through a closed gas exchange circuit 21, while the throttle valve is not included in the specified circuit. In the gas exchange circuit 21, the rarefaction existing in the housing of the receiver 1 at the time of the formation of the gas exchange circuit 21 is maintained, which prevents the growth of the gas forces acting on the piston in the disconnected cylinders and an increase in the associated friction losses.

The movable cover 3 can also be used as a controlled valve to equalize the pressure in the gas exchange circuit 21 of the shut-off cylinders 2 (14), 3 (15) relative to the pressure in the inlet receiver 1 according to the instructions of the engine control computer.

The claimed technical solution can be used for gasoline internal combustion engines.

The gas exchange system of disconnected cylinders can be manufactured using modern high-tech technologies with modern equipment.

Claims (2)

1. A gas exchange system for shut-off cylinders of an internal combustion engine, comprising a gas exchanger, the internal cavity of which has at least one on-off controlled valve and is connected at the bottom to the inlet exhaust pipes of the shut-off cylinders permanently, and to a discharge pipe connected to the catalytic manifold, with the ability to overlap the connection; in the upper part of the cavity is made, with the possibility of overlapping by a two-position valve, a hole in communication with the inlet of the gas exchange channel, the outlet of which is connected to an insulated volume formed in the receiver's housing due to the presence of additional internal walls equipped with a movable cover; the output of the specified isolated volume is connected to the inlet nozzles of the cylinders to be switched off with the possibility of forming a closed gas exchange circuit of the disconnected cylinders. 2. The system according to p. 1, characterized in that the valve control is made in the form of a computer-controlled solenoid.

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