RU2672012C2 - Reciprocating internal combustion engine and method for operating a reciprocating internal combustion engine - Google Patents

Abstract

FIELD: engines and pumps.

SUBSTANCE: invention can be used in the internal combustion engines. Reciprocating piston internal combustion engine comprising cylinder head (3) arranged at least one air inlet valve (5) and at least one exhaust valve (6), an electromagnetic valve (4) for introducing air into the combustion chamber (13) and / or air output from the combustion chamber (13) is arranged. Electromagnetic valve (4) in open position pneumatically connects the combustion chamber (13) and the pneumatic accumulator (1) through the pneumatic duct (2a). Pneumatic accumulator (1) is designed to supply the vehicle's air brake. Electromagnetic valve (4) is controlled by control unit depending on the pressure and / or temperature of the pneumatic system, the position of the piston, load requirements, engine speed and / or boost pressure in the cylinder. Control unit is designed so that in operating states in which the total engine torque is not required for the at least one cylinder with the fuel injection shut off, electromagnetic valve could be opened (4) when moving up the piston (7) and close in the top dead center range to take the compressed air out of the combustion chamber (13) and feed it to the pneumatic accumulator (1). Control unit is also designed so that, in the compression stroke of the forced idle mode, immediately after closing the intake valve (5), open the solenoid valve (4) for additional pressurization of the compressed air and, at the latest, when the gas pressure in the cylinder reaches the pressure in the pneumatic accumulator (1), close it again. Engine, an industrial vehicle with a reciprocating internal combustion engine and a method of operating a reciprocating internal combustion engine are disclosed.

EFFECT: technical result is to reduce emissions of nitrogen oxide and soot in the processes of acceleration from idling or low part load of the engine.

13 cl, 3 dwg

Description

The invention relates to a reciprocating internal combustion engine and to a method for operating a reciprocating internal combustion engine.

Diesel engines for automobiles, in particular industrial vehicles, are equipped with gas turbine supercharging (ATL) according to the prior art. Achieved with this increased excess air leads to reduced emissions of nitric oxide and particles. The problematic operating ranges are, however, acceleration processes from idle or low part load, since by the time of acceleration there is still not enough boost pressure to constantly maintain a high excess of air. The consequence of this is increased emissions of nitric oxide and particles (soot emissions) in acceleration processes.

It is known from practice that to minimize this drawback, additional pressurization of the air is provided, during which the air from the pneumatic brake system of the car is directed to the charge air distribution pipe during acceleration. A return blow to the intake air is prevented by valves. Such valves prevent the boost air generated by gas turbine supercharging from reaching the engine. Therefore, the drawback with this approach is that all the necessary air, up to the increase in sufficient boost pressure, must be taken from the pneumatic brake system.

DE 101 29 976 B4 describes a method which, for additional pressurization of air, uses the starting valves, made as poppet valves, starting valves of a high-power engine.

The objective of the invention is to provide an improved reciprocating internal combustion engine, with which you can overcome the disadvantages of conventional reciprocating internal combustion engines. The objective of the invention is, in particular, to provide a reciprocating internal combustion engine, which is suitable for use with gas turbine supercharging to minimize emissions of harmful substances and / or which allows more efficient functioning of the reciprocating internal combustion engine. Another object of the invention is to provide an improved method for the operation of a reciprocating internal combustion engine that avoids the disadvantages of conventional operating methods.

These problems are solved by means of a reciprocating internal combustion engine and a method of operating a reciprocating internal combustion engine with features of the independent claims. Preferred embodiments and uses of the invention are the subject of independent claims and will be explained in more detail below with reference to the drawings.

According to the generalized aspects of the invention, these problems are solved by means of a piston internal combustion engine, in which an electromagnetic valve is located in addition to the air inlet or air outlet valves located on the air inlet and the air outlet of the cylinder head, through which the charge is changed in the exhaust stroke and suction stroke for introducing air into the combustion chamber and / or air outlet from the combustion chamber.

An electromagnetic valve, which is hereinafter referred to as an electromagnetically actuated injector, is, for example, an electrically controlled magnetic valve. The solenoid valve is preferably located at the end of the compressed air pipe (pneumatic line), which connects the cylinder on which the solenoid valve is located, with the pneumatic accumulator of the tactical system. Thus, the solenoid valve in the open position connects the combustion chamber of the cylinder and the pneumatic accumulator through the pneumatic line. Thus, by means of an electromagnetic valve, additional air is supplied to the combustion chamber not through a conventional pressurization air supply pipe, but through a separate pneumatic line. Intake valves and exhaust valves on the cylinder head can be implemented as poppet valves. The pneumatic accumulator may, for example, be designed to supply a pneumatic brake to a vehicle.

Preferably, a similar solenoid valve is placed on each cylinder head of the cylinder set. An electromagnetic valve for supplying air to the combustion chamber and / or for discharging air from the combustion chamber may be adjustable. By means of an accurate and quickly switched solenoid valve, it is thus possible to control the amount of air in the combustion chamber and with the intake and exhaust valves closed, for example, at a compression stroke.

For additional pressurization of the air, the solenoid valve is preferably controlled by the control unit in such a way that in the locking region of the intake valve, the solenoid valve is moved to the opening position to introduce additional air into the combustion chamber through the solenoid valve. The solenoid valve is again moved to the closed position when, or just before the pressure in the cylinder, increased due to compression in the compression stroke, exceeds the air pressure in the pneumatic system. The above range of closing the intake valve should also include times immediately before and immediately after closing the intake valve.

Since additional air must be directly introduced into the combustion chamber through the solenoid valve, it is preferred that, after closing the intake valve, there is no need for check valves. Filling the cylinder with air, including with the support of an exhaust gas turbocharger, can be carried out in the usual way, so that additional boost through the solenoid valve can only be connected if necessary. In this way, a constant high excess of air can be maintained in order to reduce emissions of nitric oxide and particles.

Preferably, the solenoid valve is configured such that the effective section of the solenoid valve, that is, the effective section for boosting the air, lies in the range of 5 to 20 mm ² , more preferably in the range of 10 to 15 mm ² . For a cylinder volume of 1.5 to 2 L, an effective cross section of 10 to 15 mm ² is particularly preferred. Thus, the preferred effective cross-section of the solenoid valve is larger than with conventional solenoid valves, and reduces the required length of time for pressurization and air extraction. This is preferable since, due to the high compression ratios in diesel engines, final compression pressures of 50 bar are achieved in the compression stroke, so that the pressure increased due to compression in the cylinder in a short time exceeds the pressure in the pneumatic system of the high pressure tank (pneumatic accumulator). The time window provided for boosting the air is thus small.

The solenoid valve through the control unit can be controlled to open and close. The control unit may be designed in such a way that the control parameters of the valve, in particular regarding the decision on whether the actuation of the electromagnetic valve is carried out in the current operating state, regarding the start of unlocking of the electromagnetic valve and / or the end of unlocking of the electromagnetic valve, are determined depending on piston position, load requirements, engine speed and / or boost pressure in the cylinder. In addition, within the framework of the invention, it is possible that the control unit is configured so that the control parameters of the electromagnetic valve are determined depending on the pressure and / or temperature in the pneumatic system containing the pneumatic accumulator.

According to a preferred embodiment, the electronic motor controller is used as a control unit for the solenoid valve. In a preferred embodiment of this embodiment, the reciprocating internal combustion engine is configured with an injector for a common fuel line. As a control unit for the solenoid valve, the common rail injector control unit can then be advantageously used, so that, for example, in the case of a diesel engine, the same electronic engine controller is used to control the diesel injectors 11 and to control the corresponding air injectors 4 driven in action in an electromagnetic way.

A piston internal combustion engine is preferably a self-ignition internal combustion engine (diesel engine). A piston internal combustion engine with an electromagnetic valve can be made, in addition, as an internal combustion engine with forced ignition of the working mixture (gasoline engine), which is explained below in more detail.

Another aspect of the invention relates to an automobile, in particular to an industrial automobile with a reciprocating internal combustion engine, according to the above aspect.

Particularly preferred is the use of the invention in industrial vehicles. In this case, the electromagnetic valve can pneumatically connect the combustion chamber to the pneumatic brake system, as mentioned above.

According to a particularly preferred embodiment, an industrial vehicle includes a first pneumatic system with a first pneumatic accumulator, for example, for supplying the brakes with compressed air, and a second pneumatic system with a second pneumatic accumulator, the second pneumatic accumulator being driven at a higher pressure than the pneumatic accumulator than first pneumatic accumulator. The second pneumatic accumulator can pneumatically communicate with the combustion chamber through an electromagnetic valve and, in addition, is configured to fill the first pneumatic accumulator with compressed air.

In this embodiment, therefore, higher compression ratios are used in the compression stroke so that the second pneumatic accumulator is filled through the selection of compressed air from the combustion chamber by opening the electromagnetic valve. This has the advantage that the pneumatic brake system can be made smaller and, with the same volume as a whole, can accumulate a large mass of compressed air. In addition, solenoid valves can be designed with smaller effective cross sections.

According to generalized aspects of the invention, there is provided a method for operating a reciprocating internal combustion engine, wherein compressed air from the pneumatic accumulator is introduced into the combustion chamber, in addition to boost air, which is introduced through at least one inlet valve into the combustion chamber. In addition, compressed air can be taken out of the combustion chamber through an electromagnetic valve and again supplied to the pneumatic accumulator. As mentioned above, additional pressurization of compressed air through the solenoid valve begins in the area of closing of at least one intake valve and ends at the latest when the gas pressure in the cylinder reaches the air pressure in the pneumatic accumulator.

The provision of an electromagnetically actuated injector, which can be controlled more precisely and actuated faster than poppet valves so that air can be introduced into the combustion chamber and / or air from the combustion chamber at short intervals allows additional preferred piston operating modes internal combustion engine by appropriate controls to open and close the valve.

According to a preferred embodiment, the method includes a stage in which, in operating conditions in which the full engine torque is not required for at least one cylinder with the fuel injection turned off, the solenoid valve is in the range of top dead center, preferably immediately before reaching the top dead center, opens and during the stroke of the piston down again closes to take compressed air from the combustion chamber and feed into the pneumatic accumulator.

The internal combustion engine according to the invention can thus, in operating conditions in which full engine power or full engine torque is not required, be used to generate compressed air. Due to the higher pressure in the cylinder that occurs in the compression stroke, the pneumatic accumulators are filled.

In this operating mode, the reciprocating internal combustion engine can also be used to recover braking energy. If the phases of the shock (forced idle without fuel injection) are used without fuel injection, as described above, to generate compressed air, then an increase in the efficiency of the system is obtained, since the braking energy is used to generate compressed air.

According to a preferred embodiment of the aforementioned embodiment, the operating state in which not full engine power is used is a forced idle mode without fuel injection. In this embodiment, the control unit controls the solenoid valve as follows. At the beginning of the compression stroke of the forced idle immediately after closing the intake valve, the solenoid valve is brought into the open position. At this point in time, the pressure in the combustion chamber is less than in the pneumatic accumulator. An additional pressurization of compressed air into the combustion chamber is carried out. Later, when the gas pressure in the cylinder or in the combustion chamber reaches the pressure in the pneumatic accumulator, the electromagnetic valve closes again. Then, in the range of top dead center, for example, in front of top dead center, the solenoid valve opens again and closes again during the piston stroke down to allow compressed air to be taken from the combustion chamber and again directed to the pneumatic accumulator.

According to this embodiment, an increased braking effect is achieved by introducing additional air into the cylinder during the compression stroke, so that by increasing the filling of the cylinder during the upward stroke of the piston, an increased compression work is achieved which acts as a brake on the crankshaft. To prevent the energy stored in the air during the return stroke of the piston acceleratingly acting on the crankshaft, the injector at the top dead center of the piston opens again and air is taken out to fill the pneumatic system.

According to another aspect of the invention, there is provided an industrial vehicle in which compressed air is generated by the described extraction of compressed air from a combustion chamber and supplied to a pneumatic accumulator, without requiring a separately built-in air compressor to generate compressed air. Another advantage of the proposed invention is, therefore, that with a suitable system design, it is possible to abandon the built-in air compressor to generate compressed air, usually found in industrial vehicles.

According to another preferred embodiment, the solenoid valve is controlled in such a way that the amount of air that is introduced through the inlet valve into the combustion chamber, by at least partial extraction with the solenoid valve, is reduced before combustion in order to purposefully raise the temperature of the exhaust gases. This solenoid-controlled combustion provides the possibility of a targeted increase in the temperature of the exhaust gases, for example to enable earlier activation of the exhaust gas treatment systems after starting the engine.

This type of operation is thus preferably used after a cold start until the engine reaches its normal operating temperature. In addition, in the idle mode and in the low load region with this embodiment, the efficiency of the exhaust gas treatment system can be improved. In this case, in contrast to the reduction in the amount of air by throttling the intake air, it is not necessary to take into account the deterioration in efficiency due to throttling losses.

According to a preferred embodiment of this embodiment, this type of operation can be carried out in the case of a self-ignition piston internal combustion engine by providing a lambda probe (oxygen sensor) in a closed control loop, the lambda probe measuring the control parameter and the solenoid valve being controlled as an actuator . Thus, the lambda control, as is known from the prior art for internal combustion engines with positive ignition of the working mixture, can be provided for a diesel engine, and it corresponds to the lambda control of a modern internal combustion engine with positive ignition of the working mixture.

Other details and advantages of the invention will now be described with reference to the attached drawings, which show the following:

FIG. 1 is a block diagram of a diesel internal combustion engine according to an exemplary embodiment;

FIG. 2 is a block diagram of a forced-ignition internal combustion engine according to an exemplary embodiment;

FIG. 3 is a block diagram of a diesel internal combustion engine according to another embodiment.

In FIG. 1 schematically shows the cylinder structure of a self-ignition internal combustion engine according to an exemplary embodiment. The piston 7, which is movably guided in the cylinder, is moved by a connecting rod driven by the crankshaft 8. At least one intake valve 5 and at least one exhaust valve 6 in the form of poppet valves are placed in the cylinder head 3. They are at the suction stroke and at the exhaust stroke in relation to the so-called gas distributor in a known manner, alternately with possible overlap of the valves, open and close again to suck in fresh combustible mixture from the charge air channel through the intake valve 5 into the cylinder and to displace exhaust gases through the exhaust valve 6 from cylinder. In addition, an exhaust gas turbocharger (not shown) can be provided that can generate excess pressure to pressurize the cylinder through the intake valve 5. Fuel is injected into the combustion chamber 3 through a diesel injector 11 located in the cylinder head.

An electrically actuated solenoid valve 4 is located in the cylinder head 3, which communicates with the combustion chamber 3. Located outside the combustion chamber 13, the opening of the magnetic valve 4 is connected to the pneumatic line 2a, through which the electromagnetic valve 4 is connected to the pneumatic system. Other cylinders of the cylinder block (not shown in FIG. 1) are made in a comparable manner.

A compressed air reservoir (pneumatic accumulator 1) is located in the pneumatic system, from which, for example, a pneumatic brake of an industrial vehicle (not shown) is supplied with compressed air. The pneumatic lines 2a from the electromagnetic valve 4 of each cylinder block are reduced through the distributor guide 10 to the pneumatic line 2b, which is connected to the compressed air reservoir. A shut-off valve 9 is also provided between the compressed air reservoir and the distributor guide 10. The compressed air reservoir, as is typically used in industrial vehicles, ranges from 10 to 12 bar.

The solenoid valve 4 is controlled by a control device of the injector system with a common fuel line, which is connected via a control line to the solenoid valve 4 (not shown). A control unit for controlling injectors 11 with a common fuel line, in particular, an end stage for controlling injectors 11 with a common fuel line, is also suitable for controlling an electromagnetic injector 4. According to the present exemplary embodiment, the same final stage that is used for controlling diesel injector 11, through the multiplexing method is also used to control the solenoid valve 4.

The control unit determines the required values or control parameters for controlling the solenoid valve 4, for example, the valve operation is “Yes” or “No”, the start of opening and the end of opening of the solenoid valve 4. The control parameters are determined depending on the current load requirement, speed engine and boost pressure, which are already available in the control device for controlling diesel injectors 11. In addition, the control device is configured to, via digital erfeys other disposed in the vehicle control devices either directly from the respective sensors 17, determine the pressure and temperature in the air intake system as the other variables used to calculate control parameters. In this exemplary embodiment, a pressure and temperature measuring sensor 17 is located on the compressed air tank, and an additional pressure and temperature measuring sensor 17 is located on the distributor guide 10 to measure pressure and temperature in the compressed air tank or in the distributor guide 10.

FIG. 2 shows an embodiment of the embodiment of FIG. 1 for a forced ignition internal combustion engine, so that the foregoing description may be referred to to avoid repetition. A feature of this internal combustion engine is that instead of a diesel injector 11, a spark plug 12 is provided with which a mixture of air and fuel is ignited in the combustion chamber 13. In addition, an upstream check valve 15 is provided upstream of the solenoid valve 4 in the pneumatic line 2 to prevent the combustible mixture from the combustion chamber 13 from entering the pneumatic system through the solenoid valve 4.

FIG. 3 shows yet another embodiment of the embodiment of FIG. 1 and differs from it in that only a two-stage pneumatic system is provided. In contrast to the exemplary embodiment of FIG. 1, the individual cylinders through their respective solenoid valves 4 and pneumatic lines 2a are not directly connected to the compressed air reservoir, from which, for example, the pneumatic brake of an industrial vehicle is supplied. Moreover, the second pneumatic accumulator 14 (reservoir of compressed air), which is operated at a higher pressure than the first reservoir of compressed air, is placed between the first reservoir of compressed air and the cylinders.

In this embodiment, the pressure and temperature measuring sensor 17 is located, respectively, on the first compressed air reservoir, on the second pneumatic accumulator 14 and on the distributor guide 10, in order to measure pressure and temperature, respectively, in the first compressed air reservoir, in the second pneumatic accumulator 14 and in distributor guide 10.

While the first compressed air reservoir is typically operated in a range of 10 to 12 bar, the second compressed air reservoir is a high pressure reservoir that is operated at a pressure of the order of 30 bar.

Both pneumatic accumulators are connected through the pneumatic line 2c. Between both reservoirs of compressed air there is a check valve 15 and a pressure regulator 16. Due to the high compression ratios in diesel engines, final compression pressures of the order of 50 bar are achieved. Thus, using the above-described methods, it is possible to fill the high-pressure pneumatic accumulator 14 through the electromagnetic valve 4 with compressed air generated in the compression stroke. The pressurization of the cylinders is also carried out from the pneumatic accumulator 14. Through the pressure regulating valve 16 or other controlled valves, a normal reservoir of compressed air is filled from the pneumatic accumulator 14.

The device of FIG. 3 with a two-stage pneumatic system has the following advantages: the pneumatic system for the brake can be made smaller because the air stored in the high-pressure system is provided as a reserve. With the same volume, a large mass of compressed air can be accumulated in the high-pressure system. In addition, with the same volume as a whole, a large mass of compressed air can be accumulated. Another advantage is that the solenoid valve 4 can be made with a smaller effective cross section because the air from the high pressure system has a higher density and because more time is provided for pressurization during the compression phase. Valves 4 with a smaller effective cross section can also be made smaller and, therefore, require less structural space in the cylinder head 13. Finally, the advantage is that the masses to be transported at smaller effective cross sections are smaller. Therefore, also technical implementation can be carried out more simply and leads to reduced costs.

Preferred methods of operation have already been described which can be implemented with the configuration of the solenoid valve 4 in the cylinder head 3 of a piston internal combustion engine according to the invention. They will be further explained again for an example based on the diesel internal combustion engine of FIG. one.

The first mode of operation includes additional pressurization of the air, especially during acceleration from idle or reduced partial load, when the exhaust gas turbocharger does not provide sufficient boost pressure to fill the cylinder with air.

When the control unit of the solenoid valve, for example, depending on the engine speed and the detected boost pressure, determines that there is not enough filling of the cylinder through the intake valve 5, the control unit activates the operation of the solenoid valves of the 4 cylinders and determines the start of opening and the end of opening of the valves during four-stroke process.

For additional air pressurization, the solenoid valves 4 are controlled by a control unit in such a way that the electromagnetic valve is switched to the open position in the locking range of the intake valve to supply additional compressed air, which is provided from the pneumatic accumulator 1, to the combustion chamber 13 through the electromagnetic valve 4. Solenoid valve 4 is again brought to the closing position when or before the pressure in the cylinder, increased by compression in the sealing stroke, exceeds the pressure ix air in the compressed air tank.

Filling the cylinder with air primarily depends on the current boost pressure. Therefore, the additional air blown through the electromagnetic valve 4 can be continuously reduced depending on the increasing boost pressure. If the boost pressure reaches the required value, then the additional air supply is turned off.

Through the first mode of operation, a continuously high excess of air can be maintained in order to reduce emissions of nitric oxide and particles.

The second mode of operation can be used to generate compressed air.

By controlling the solenoid valve 4 so that it opens when the gas pressure in the combustion chamber is higher than the air pressure in the compressed air tank, compressed air flows from the combustion chamber 13 through the electromagnetic valve 4 and into the pneumatic system of the compressed air reservoir. The compression stroke of the cylinder is therefore used to generate compressed air, which is discharged through the solenoid valve from the combustion chamber 13. Such generation of compressed air is preferably carried out in operating conditions in which not full engine power or full engine torque is required. In this case, in one or more cylinders, fuel injection is turned off, which in itself is known from the prior art. After compression of the air in the cylinder, the solenoid valve 4 opens in front of the top dead center. Due to the higher pressure in the cylinder, the pneumatic accumulator 1 (compressed air reservoir) is filled. When the pressure in the cylinder due to decompression during the downward movement of the piston 7 drops below the pressure in the pneumatic accumulator 1, the electromagnetic valve 4 is again closed.

The third mode of operation can be used to recover braking energy. In this case, the phases of forced idle without fuel injection are used to generate compressed air according to the second mode of operation. From here follows an increase in the efficiency of the system, since the braking energy is used to generate compressed air.

The fourth mode of operation can be used to support braking. An additional advantage of the invention is that in the forced idle mode without fuel injection, the operation mode of the electromagnetic valve 4 can be implemented in such a way that the engine braking effect is increased. First of all, it is necessary to establish that there is an action of braking only due to the generation of compressed air, since the kinetic energy is converted, which is the result of the car’s movement, to an increased pressure level in the pneumatic accumulator system. An increased braking effect can also be generated if, at the beginning of the compression stroke, immediately after closing the intake valve 5, the injector 4 opens, and thereby additional air is supplied to the combustion chamber 13. At the latest, when the pressure in the cylinder or combustion chamber 13 and in the pneumatic system of the pneumatic accumulator 1 is equalized, the injector 4 closes again. Due to the increased filling of the cylinder, during the upward movement of the piston 7, an increased compression work is performed, which inhibits the crankshaft (not shown). In order to prevent that the energy stored in the air during the downward stroke acceleratedly acts on the crankshaft, the injector 4 at the top dead center of the piston 7 opens again. The air supplied at the beginning of the process is returned back to the pneumatic system 1. In this case, the method can be performed in such a way that more air is returned to the pneumatic system 1 than was taken, due to which this mode of operation can also serve to fill the pneumatic system 1. Thus This ensures an increase in the efficiency of the internal combustion engine, since the braking energy is used to generate compressed air.

Within the scope of the invention, in addition, there is the possibility shown in FIG. 1 system due to the appropriate calculation of the pneumatic accumulator and the operating modes in which compressed air is generated, to design in such a way that due to this the need for compressed air of the car is covered, and thus it is possible to completely abandon the air compressor to generate compressed air, usually built in cars industrial purpose.

The fifth mode of operation of the magnetic valve 4 involves reducing the amount of air for the combustion process. Moreover, using a magnetic valve 4, part of the air in the cylinder after changing the charge (working mixture), before ignition of the mixture is taken from the combustion chamber 13. Due to this, the temperature of the exhaust gases is purposefully raised in order to, for example, provide the possibility of early activity of the exhaust gas treatment system after starting the engine. Also at idle and in the area of low load, this measure can increase the efficiency of the exhaust gas treatment system. A particular advantage of this mode is that, in contrast to reducing the amount of air due to the throttling of the intake air, it is not necessary to take into account any degradation in efficiency due to throttling losses.

In addition, it is possible to carry out the aforementioned operating mode by applying a lambda probe in a closed control loop according to the fifth operating mode. In this case, similarly to lambda control in internal combustion engines with forced ignition of the working mixture, by controlling the air introduced into the combustion chamber through the solenoid valve 4, a predetermined mass-air ratio is regulated in the combustion chamber 13. A similar control method is known from the prior art for the operation of internal combustion engines with forced ignition of the working mixture and, with the corresponding functioning of the electromagnetic valve 4, can also be used for a diesel engine.

The above various modes of operation of internal combustion engines when controlling the solenoid valve 4 are particularly preferred for the operation of a diesel engine, as shown schematically in FIG. one.

However, the above modes of operation can also, with limitations and modifications, be used in an internal combustion engine with forced ignition of the working mixture, as shown in FIG. 2.

Similarly to the operation method of the diesel engine, the electromagnetic valve 4 can, according to the first operating mode, function in such a way that, by means of the electromagnetic valve 4, additional compressed air is introduced into the combustion chamber 13 in order to provide an additional possibility to influence the mass ratio of air and fuel in the combustion chamber 13.

If, as shown in FIG. 2, a check valve 15 is provided to prevent the combustible mixture from the combustion chamber 13 from entering the pneumatic system; the above-mentioned operating modes in which air compressed from the combustion chamber 13 from the combustion chamber 13 is taken out by means of the electromagnetic valve 4 are not possible. This restriction is valid regardless of the type of mixture formation. Both with classical external mixture formation and with direct injection into the combustion chamber, at least from time to time there is a combustible air-fuel mixture in the cylinder during compression.

If, however, instead of a non-return valve 15, another means of control is provided in the pneumatic lines 2a, 2b, for example, using the corresponding sensors and / or shut-off valves in the lines, then it is possible to operate an electromagnetic solenoid in internal combustion engines with forced ignition of the working mixture with direct injection valve 4 in the aforementioned third and fourth operating modes for recovering braking energy and for supporting braking.

In addition, the above fifth mode of operation for reducing the amount of combustion air can also be used to save fuel. In this case, the throttle valve also remains substantially open in the partial load range. Due to this, throttling losses are reduced. Part of the air in the cylinder is discharged through the electromagnetic air valve 4. If the air mass in the cylinder meets the requirements of the load, then the air valve 4 closes and compression begins.

At the same time, the higher the efficiency, the later fuel injection is introduced, since up to this point in time it is required that the air valve be closed. The more time is allowed for air discharge, the more air can be discharged through the solenoid valve 4 and the more the throttle valve can open, thereby minimizing throttling losses.

The above operation mode for diesel engines in which in working condition, which does not require full engine power or full engine torque, and one or more cylinders operate with fuel injection turned off, when setting lambda = 1-regulation is not implemented in an internal combustion engine with forced ignition of the working mixture, but can be implemented in an engine running on a lean mixture.

All operating modes place high demands on engine control, especially in lambda = 1-mode. Usually a modern internal combustion engine with forced ignition of the working mixture works with pre-regulated fuel injection, which is superimposed on the fast lambda control. For fuel control, the air mass is recorded by an air mass meter or calculated from the pressure in the intake channel. The mass of fuel required for stoichiometric combustion is calculated from the air mass. Neither the air mass sensor nor the pressure sensor can detect air that is additionally introduced or discharged through the air valve. Therefore, this air mass in this embodiment is very accurately calculated by the engine control system.

Although the invention has been described with reference to specific exemplary embodiments, many variations and modifications are possible that also apply the ideas of the invention and therefore fall within the scope of protection. Therefore, the invention should not be limited to the disclosed specific examples of execution, but should cover all such examples of execution that fall in the field defined by the attached claims.

List of Reference Items

1 compressed air tank / pneumatic accumulator 12 bar

2a, 2b, 2c pneumatic line

3 cylinder head

4 solenoid valve

5 intake valve

6 release valve

7 piston

8 connecting rod

9 shutoff valve

10 air distributor guide

11 diesel injector

12 spark plug

13 combustion chamber

14 compressed air tank / pneumatic accumulator 30 bar

15 check valve

16 pressure regulator

17 measuring pressure and temperature sensor

Claims (26)

1. A piston internal combustion engine with at least one intake valve (5) located on the cylinder head (3), and at least one exhaust valve (6) located on the cylinder head, and with an electromagnetic valve located on the cylinder head (3) (4) for introducing air into the combustion chamber (13) and / or for discharging air from the combustion chamber (13), moreover, the electromagnetic valve (4) in the open position pneumatically connects the combustion chamber (13) and the pneumatic accumulator (1) through the pneumatic line (2a), moreover, the pneumatic accumulator (1) is designed to power the pneumatic brake of the car, moreover, the electromagnetic valve (4) by means of a control unit is configured to control depending on the pressure and / or temperature of the pneumatic system, the position of the piston, load requirements, engine speed and / or boost pressure in the cylinder, and the control unit is designed so that in working in conditions in which the full engine torque is not required, for at least one cylinder with the fuel injection turned off, open the solenoid valve (4) while moving up the piston (7) and in the range of the upper m rtvoy point close again to select the compressed air from the combustion chamber (13) and to submit to the pressure accumulator (1), characterized in that the control unit is also designed to open the solenoid valve (4) for additional pressurization of compressed air and, at the latest when the gas pressure in the cylinder reaches air accumulator (1), close it again. 2. A piston internal combustion engine according to claim 1, characterized in that the effective cross section of the electromagnetic valve (4) lies in the range from 5 to 20 mm ² , more preferably in the range from 10 to 15 mm ² . 3. The piston internal combustion engine according to claim 1 or 2, characterized in (a) that the control unit is an electronic engine controller; or (b) that the reciprocating internal combustion engine is configured with an injection system with a common fuel line, and that the control unit is a control unit for an injection system with a common fuel line. 4. The piston internal combustion engine according to claim 1 or 2, characterized in (a) that the reciprocating internal combustion engine comprises an exhaust gas turbocharger; and / or (b) that at least one intake valve (5) and exhaust valve (6) are configured as poppet valves; and / or (c) that the reciprocating internal combustion engine is a self-ignition internal combustion engine or a positive ignition internal combustion engine. 5. A car, in particular an industrial vehicle with a reciprocating internal combustion engine according to any one of claims 1 to 4. 6. An industrial vehicle with a piston internal combustion engine according to any one of claims 1 to 4, characterized by a first pneumatic system with a first pneumatic accumulator (1) for supplying the brakes with compressed air and a second pneumatic system with a second pneumatic accumulator (14), the second pneumatic accumulator (14) ) is configured to operate with a higher pressure than the first pneumatic accumulator (1), and is configured to pneumatically couple to the combustion chamber through an electromagnetic valve (4), wherein Oh pneumatic accumulator (14) is configured to fill the first pneumatic accumulator (1) with compressed air. 7. The method of operation of a piston internal combustion engine according to any one of claims 1 to 4, characterized in (a) that compressed air from the pneumatic accumulator (1) is introduced through the electromagnetic valve (4) into the combustion chamber (13), in addition to the boost air, which is introduced through the at least one intake valve (5) into the combustion chamber (13), and / or (b) that the compressed air through the electromagnetic valve (4) is taken from the combustion chamber (13) and is supplied to the pneumatic accumulator (1). 8. The method according to claim 7, characterized in that the additional pressurization of compressed air through the solenoid valve (4) begins in the closing area of the at least one inlet valve (5) and ends at the latest when the gas pressure in the chamber (13) combustion reaches air pressure in the pneumatic accumulator (1). 9. The method according to claim 8, characterized in that in operating conditions in which the full engine torque is not required, for at least one cylinder with the fuel injection turned off, the electromagnetic valve (4) is opened when the piston (7) moves up and In the upper dead center range, they are again closed to take off compressed air from the combustion chamber (13) and feed it into the pneumatic accumulator (1). 10. The method according to claim 9, characterized in that in the compression phase of the forced idle immediately after closing the intake valve (5), the electromagnetic valve (4) is opened for additional pressurization of compressed air and, at the latest, when the gas pressure in the cylinder reaches the pressure in the pneumatic accumulator (1), close again. 11. The method according to claim 8, characterized in that after changing the charge of the working mixture and before ignition through the electromagnetic valve (4), the air in the cylinder is at least partially taken from the combustion chamber (13). 12. The method according to claim 11, characterized in that (a) a piston internal combustion engine is a self-ignition piston internal combustion engine; and (b) that air is drawn through the solenoid valve (4) as an actuating element in a closed control lambda circuit. 13. The method according to any one of claims 7-12, characterized in that the control parameters regarding the start of unlocking of the electromagnetic valve (4), the end of unlocking of the electromagnetic valve (4) and the decision whether the activation of the electromagnetic valve (4) is carried out, is determined in depending on the pressure and / or temperature in the pneumatic system containing the pneumatic accumulator (1), on the position of the piston, load requirements, engine speed and / or boost pressure in the cylinder and / or intake manifold.

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