DE10032669A1 - Method and appliance for load control of externally ignited IC engine without accelerator employs rapid acting restrictor valve in air inlet pipe - Google Patents

Abstract

In the air inlet pipe (7) a restrictor valve (13) is fitted. Compared to the time needed for the inlet valve (3) to open the restrictor valve can close very rapidly to block the inlet pipe. In the closing direction the restrictor valve is assisted by the air flow. During the opening interval of the inlet valve the restriction valve can be closed to control the air/fuel mixture according to the load point of the IC engine.

Description

The invention relates to a method for unthrottled Load control of a spark ignition internal combustion engine (BKM) specified in the preamble of claim 1 Genus and a device according to the preamble of Pa claim 6.

With spark-ignited BKMs, each cylinder is over min least one inlet duct combustion air supplied with Fuel mixed and in the cylinder to drive the is burned in the longitudinally movable piston. The exhaust gases are opened with each work cycle by opening one Exhaust pushed out of the respective cylinder. To the The fresh charge is changed by temporarily opening it an intake valve in the intake port supplied to the cylinder. The mixture of combustion air and fuel is in egg to mix an ignitable ratio to prevent ignition candle to be ignitable. With higher operating load of the BKM is getting more and more fuel to burn in every area beitsspiel required and must have a larger air mass in be assigned to each work cycle. A well-known measure The load control is the adjustment of the air throughput zes of the inlet channel by an adjustable in the inlet channel arranged throttle valve or similar throttle bodies. The Load control by throttling the combustion air flow however, inevitably brings about a deterioration in the effect degree of the BKM with itself. The reductions in efficiency  are also called throttling losses and tre particularly when the BKM is idling and in the lower one Partial load range when the piston in the cylinder generated suction pressure below the ambient pressure the BKM is located.

The efficiency losses of the BKM are with unthrottled Load control significantly lower. A well known measure for unthrottled load control is the control of the Air throughput of the inlet ducts is variably adjustable bare gas exchange valves. The inlet valves can for example in the stroke or in the opening time be adjustable and in the opening intended for gas exchange voltage intervals are set such that the desired volume flow in the cylinder results. To implement variable valve control are available different constructions known, but very complex are and in the end result are not satisfactory results nisse in reducing throttle losses NEN.

It is also known to have a constantly driven actuator link instead of the throttle valve for load control in on lasskanal to arrange. The actuator temporarily switches on let channel free, the size of the released through passage cross-section of the inlet channel due to the constant Movement of the actuator oscillates. In the essay "A High Expansion Ratio Gasoline Engine with Intake Control Rotary valve installation "Ichimaru et al., See JSAE Review Vol. 14, No. 4, pp. 12-14, October 1993 Rotating actuator for throttle-free load control proposed. It is also known to oscillate the actuator releasing the inlet duct is movable longitudinally to build. Such a slit control, in the opening slots  in a longitudinal slide in overlap with Inlet openings can be brought to the cylinder, for example from the essay "A Non-Throttled Gasoline Engine Using a Variable Shutter Valve ", S.C. Low, SAE Paper 911229, 1991, pp. 83-89.

The present invention is based on the object Method and device for unthrottled load control of an externally ignited BKM, which with low construction effort an improvement in effectiveness degree of BKM.

This object is achieved by a method with the features of claim 1 and with respect to the front direction solved with the features of claim 6.

The invention provides an unthrottled load control spark-ignited BKM before, with a check valve in the inlet duct the air flow rate according to the requested loading driving load of the BKM controls. The check valve is selected rend the opening interval of the intake valve for the purpose of the fresh gas inlet with each work cycle between ge opened and closed switching state switched. For this purpose, the check valve has a quickly switchable Ver conclusion on that in a compared to the opening time of the intake valve short actuation time between the one release channel and a locking position around is switchable. The inlet channel is temporarily open netem inlet valve blocked, which is in the between Check valve and inlet valve lying portion of the one let channel forms a negative pressure, which the Luftrei Exercise losses when fresh gas is introduced into the cylinder reduced.  

The check valve can at the beginning of the opening interval of Intake valve will be open and will open during opening interval of the inlet valve in the closed state switched. The closure member of the check valve is there appropriately designed so that the flow direction of the Fresh gas under the closing movement of the closure member supports. By closing the check valve, the in the amount of fresh gas entering the cylinder is limited according to present load point of the BKM. After closing the Inlet channel through the check valve builds up in the inlet channel a negative pressure until the end of the opening interval of the Intake valve. From the overlay of the tax times of the The check valve and the inlet valve result in a limitation increase in the amount of fresh gas drawn in, without that of the übli Chen load controls connected by throttle valves Flow losses. The check valve is useful ge during the opening actuating movement of the inlet valve closed.

In an alternative embodiment of the invention that is Stop valve at the beginning of the opening interval of the inlet valve is closed and is in when the inlet valve is open switched the fully open state. in this connection the check valve is advantageously designed such that the closure member of the check valve in the flow direction device of the inlet channel can be lifted off from the valve seat is. When opening the check valve, there is a strong one Air flow, which is particularly in the case of fuel injection into the inlet channel a good swirl of the injected fuel results. The opening of the lock Valve is advantageously done during the closing Intake valve movement.  

The load control according to the invention of a spark ignition BKM reduces the principle-related ones with throttled BKM Loss of air friction and thus reduces fuel consumption the BKM. The known unthrottled load controls such as lean mixture engines with stratified mixture associated disadvantages such as increased nitrogen oxide emissions with lean mixture combustion and for charge stratification necessary injection devices are avoided. The Invention comes out with little structural effort, esp in particular, the check valve provided according to the invention even without design changes to conventional Zylin the heads of a BKM. This gives overall a reduction in the operating costs of the BKM, which are of a similar size to that of the varia bale and flexible valve control of the gas exchange valves, the be from a variety of complicated control components stands. The device according to the invention is compared to a variable valve timing easier and cheaper and gets by with a lower energy requirement, since this is invented stop valve according to the invention with a fast-switching closure link with little effort in control technology and can be done with inexpensive materials.

The device according to the invention is conventional with all Chen internal combustion engines with mechanical cam control the gas exchange valves are compatible via a camshaft, so that the unthrottled load control according to the invention a variety of motors can be used and also can be retrofitted. The invention can be advantageous in conjunction with direct fuel injection into the cylinders be used, the injector the cylinders individually assigned. The check valve according to the invention can can be optimally introduced into the inlet duct and a dead volume  avoided between the check valve and the inlet valve become.

By permanently closing the shut-off valves and switching off Fuel metering and ignition can also be used individual cylinders can be switched off. Because the flow connection is interrupted between the intake port and the cylinder, the efficiency losses of the BKM are reduced due to the Kol still moving in the deactivated cylinders ben. The BKM can in particular with a low operating load so fuel can be saved. By alternating Shutting down individual cylinders can cool them down individual cylinders can be counteracted.

Exemplary embodiments of the invention are described below the drawing explained in more detail. Show it:

Fig. 1 shows a cross section of a spark-ignition BKM with un throttled load control by means of a shutoff valve OF INVENTION to the invention,

Fig. 2 is a graph of the opening cross sections of the inlet valve and of the shutoff valve according to the apparatus of FIG. 1,

Fig. Is a cross section of a BKM with an alternative design to the arrangement of FIG. 1 Sperrven til 3,

Fig. 4 is a graph of the opening cross sections of the check valve and the intake valve of the BKM accelerator as Fig. 3,

Fig. 5-7 cross-sectional views of the check valve of an arrangement, according to Fig. 1 in different positions,

FIGS. 8 and 9 are cross-sectional views of a shut-off valve with a cylindrical closure member in the open and ge schlossenem state.

Fig. 1 shows a spark-ignited BKM 1, in which cylinders 10 are each a piston 8 is arranged longitudinally movably, and a combustion chamber 31 limited. The combustion chamber 31 is closed by egg NEN resting on the cylinder 10 cylinder head 32 , in which an inlet duct 7 for the supply of fresh gas and an outlet duct 9 for discharging the exhaust gases arising in each working cycle of the cylinder 10 are discharged in the direction of the arrow. The access of the inlet channel 7 to the combustion chamber 31 is controlled by an inlet valve 3 , which presses the valve tappet of the inlet valve into the combustion chamber 31 by a control cam 4 during the timing provided for the fresh gas inlet in the cylinder 10 and thus accesses the inlet channel 7 to the combustion chamber 31 releases. In a corresponding manner, an exhaust valve 2 is arranged in the exhaust duct 9 , which is opened by a control cam 5 during the exhaust cycle for exhaust gas discharge from the combustion chamber 31 . The control cams 4 and 5 , which determine the opening times of the inlet valve 3 and the outlet valve 2 during the working cycle of the cylinder 10 , who are driven in a known manner by a crankshaft of the BKM 1, which is not shown here.

For the fuel metering, an injector 6 is assigned to each cylinder 10 . In the present embodiment of a direct injection BKM 1 , the injector 6 is arranged in the cylinder head 32 . The fresh air supplied via the inlet channel 7 is mixed in the combustion chamber 31 with the direct injected fuel. An ignitable fuel / air mixture is formed, which is to be ignited by the spark egg ner arranged in the cylinder head 32 spark plug 11 .

In such a BKM 1, known per se in construction, it follows the load control by setting the air throughput of the inlet duct 7 in accordance with the operating load of the BKM and the associated fuel metering. The load control takes place according to the invention without throttling by means of a check valve 12 arranged in the inlet channel 7 upstream of the inlet valve 3 . The check valve 12 has a quickly switchable valve member and is switched in each Ar beitsspiel the cylinder with the inlet valve open for the purpose of gas exchange in the combustion chamber 31 between the open and closed switching state. The Sperrven valve 12 is formed in the present embodiment as a tappet valve with a in the flow direction of the inlet channel 7 longitudinally movable valve tappet 14 , which forms a closure member at its free end carries the valve plate 13 . The valve plate 13 can be lifted off from a valve seat 16 to open the check valve 12 and to release the inlet channel 7 . The switching state of the check valve 12 is switched by an actuator 15 which acts on the valve tappet 14 . The actuator 15 operates in the present exemplary embodiment electrically, but can also be designed with a pneumatic control or similar. The structure of the check valve 12 and the actuator 15 is explained in more detail below with reference to FIGS. 5 to 7.

As the diagram in FIG. 2 shows, the cam 4 which is positively controlled by the control cam is controlled with an oscillatingly variable opening cross section V2 in the manner of an oscillation. The opening stroke of the inlet valve 3 starts from the closed state (opening stroke 0%) at the time T1, which is in the working cycle of the cylinder 10 before the top dead center of the piston movement. The cam control leads to the course of the opening stroke shown in the drawing in the manner of a silicon oscillation, the released opening cross-section decreasing in mirror image symmetry after reaching the maximum valve opening in the present exemplary embodiment until fully closing at time T3.

The check valve 12 for unthrottled load control of the BKM 1 is controlled in coordination with the control times of the intake valve in accordance with the lift curve V1 and is in the open state at the beginning of the opening interval of the intake valve, which lies between the times T1 and T2. During the opening movement of the inlet valve and the associated increase in the opening cross section according to the opening curve V2, the check valve is switched to the closed switching state at time T2. By the quick closing of the shut-off valve and the associated closing of the inlet channel 7 , the supply of combustion air to the combustion chamber 31 is prevented and the amount of combustion air drawn in is limited to the intended extent. The time T2 for closing the check valve 12 is determined according to the present load point of the BKM 1 and the fresh air quantity provided for this load point. The amount of combustion air metered to the combustion chamber depends on the resultant opening of both the inlet valve and the check valve. The hatched area VR in the drawing corresponds to the overlap of the control times of the check valve and the intake valve and the resulting opening of both valves and is a measure of the amount of combustion air supplied to the cylinder 10 . From the superposition of the valve openings of both the inlet valve 3 and the check valve 12 results in the limitation of the intake air quantity required for load control, without the efficiency losses associated with conventional load control by means of a throttle valve.

The check valve, which is in the present Ausführungsbei game at the beginning of the opening interval of the inlet valve until time T2 in the open state, is moved to close the check valve in the flow direction of the combustion air in the inlet channel of the actuator 15 be. The flowing combustion air acts on the valve plate 13 and supports the closing Stellbewe movement of the valve plate 13 until it comes to rest on the valve seat 16 to close the check valve 12 . In this way, the closing process of the shut-off valve can be carried out with very little energy expenditure, and likewise the acceleration of the closing process results from the support of the closing movement by the flowing combustion air, so that the amount of combustion air to be metered can be adjusted more precisely.

Fig. 3 shows an alternative embodiment of the check valve according to the invention, which is controlled with the stroke curves shown in Fig. 4 Darge. For the BKM 1 , the same reference numerals are used in FIG. 1 for the same components. The opening stroke V2 of the inlet valve is positively controlled by the control cam 4 . Accordingly, the opening stroke V2 in the illustration in FIG. 4 runs in accordance with the illustration in FIG. 2, the opening stroke of the inlet valve 3 begins at the time T1 before the top dead center of the piston movement. In the held difference to the process at unthrottled load control according to Fig. 1 and 2 of Fig. 3 and 4 in the present embodiment, the check valve at the beginning of Öffnungsin tervalles of the intake valve closed. The opening of the check valve takes place during the closing movement of the inlet valve. By quickly opening the blocking valve, the inlet channel 7 is released at time T4 and the combustion chamber is supplied with combustion air. The amount of combustion air is precisely measurable according to the operating load by varying the opening time of the check valve 12th The amount of combustion air corresponds to the overlap of the opening times of the shut-off valve and the intake valve according to the hatched area VR, which corresponds to the resulting opening of both valves.

The in the present embodiment with an open a check valve check valve 12 has a Ventiltel ler 13 which can be lifted in the flow direction of the inlet channel 7 from its valve seat 16 . The vacuum generated by the piston 8 in the inlet channel when the inlet valve 3 is open supports the opening movement of the valve tappet 14 , the flow in the inlet channel 7 also acting on the valve plate 13 when the check valve 12 opens and accelerating the opening movement. The vorlie embodiment of the invention is particularly suitable for BKMn with intake manifold injection, the injector 6 depending on the cylinder 10 is arranged in the channel wall of the inlet channel 7 and injects the fuel into the combustion air flowing in the channel. By opening the shut-off valve 12 with the inlet valve 3 already open, there is a strong swirl by the combustion air suddenly entering the inlet channel 7 , whereby the mixing with the injected fuel is improved for the purpose of a homogeneous mixture formation.

The check valve 12 shown schematically in FIG. 1 is shown enlarged in the representations of FIGS. 5 to 7. The actuator of the check valve 12 has two coils 17 , 17 ′ arranged one behind the other in the axial direction of the valve tappet 14 . The valve lifter 14 carries a cylindrical actuator 18 made of magnetically permeable material, which is movable in the magnetic fields of the coils 17 , 17 '. The valve tappet 14 penetrates the interior of the coils 17 , 17 'and is guided in the axial direction in bearings lying adjacent to the coils 17 , 17 '. The actuator of the Sperrven valve 12 with its two coils 17 , 17 'is in the present embodiment is arranged outside the inlet channel 7 , the valve tappet 14 with its valve end 13 arranged at the free end can be inserted into the inlet channel 7 to close the channel. In the inlet channel 7 , a valve seat 16 is formed, on which the valve plate 13 can be placed to close the inlet channel 7 . The valve seat 16 is hen with an elastic pad 21 verses, which ensures a dampened placement of the valve plate 13 . In the present exemplary embodiment, the outflow direction of the combustion air flow L1 from the valve seat 16 is coaxial with the axis of the valve lifter 14 . The one lasskanal 7 is angled in the area of the check valve 12 in the present embodiment, the fresh air opening through a connecting piece 20 at an angle to the tappet axis into the section of the inlet channel 7 leading to the cylinder. The axial direction of the valve tappet 14 lies at an angle of less than 90 ° to the direction of flow in the connecting piece 20 .

In the illustration of FIG. 5, the check valve is in the open position, the flow connection between the connection piece 20 and the leading part is to BKM of the inlet channel 7 is released. In the region of the mouth of the connecting piece 20, a protrusion 22 is formed, which the valve plate 13 axially overlaps in the open position of the check valve 12 so that the valve is protected from exposure plate 13 of the incoming air flow L1. The valve tappet 14 can be pushed out against the force of a return spring 19 to close the check valve 12 ; in the illustration of Figure 5 is located. the check valve 12 in the rest position of the return spring 19. When the valve tappet 14 is pushed out, the spring 19 acts reset on the valve tappet 14 , the spring force of the return spring 19 being appropriately dimensioned such that the valve tappet 14 can be returned without the coils 17 , 17 'being supported.

To close the check valve 1 , the coils 17 , 17 'are energized one after the other and thus transport the actuator 18 , which pushes out the valve tappet and moves the valve plate 13 in the direction of the valve seat 16 . As shown in FIG. 6, the valve plate 13 is detected on its path to the valve seat 16 in the connecting piece 20 as soon as the valve plate has left the protected rest position covered by the projection 22 . During the actuating movement, the valve plate 13 is detected on the way to the valve seat 16 by a partial flow L2 of the supplied combustion air on its side facing away from the valve seat 16 . The closing movement of the check valve 12 is supported by the pressure effect of the air flow L2 on the pressurized annular surface of the Ven tilteller 13 .

In the closed position of the shut-off valve according to FIG. 7, the valve plate 13 lies sealingly on the elastic support 21 of the valve seat 16 , the coil 17 ′ facing the valve element 13 acting on the actuator 18 and holding the valve plate 13 in the closed position. The air pressure P in the connecting piece 20 also acts sealingly on the facing annular surface of the valve plate 13 .

In the lying between the check valve 12 and the BKM section of the inlet channel 7 , a ventilation hole 23 is arranged through which the negative pressure in the lead to the BKM part of the inlet channel 7 can be reduced after closing the check valve 12 . The ventilation opening 23 is connected via a ventilation line 24 to the surroundings of the BKM or preferably to the outlet of the cylinder or an exhaust line of the BKM which summarizes all the outlets. Due to the negative pressure in the inlet channel 7 , a gas flow L3 is established through the ventilation opening 23 , which reduces the negative pressure in the inlet channel 7 . The cross section and the position of the ventilation opening 23 is expediently chosen so that the negative pressure in the inlet channel 7 has already built up to the subsequent opening of the inlet valve in the following working stroke of the respective cylinder, and the mass flow of the air flow L3 remains so low that none Flow losses arise. By connecting the ventilation line 24 into the outlet of the BKM and the associated recirculation of small amounts of exhaust gas, there is no disturbance in the amount of fresh air metered by the check valve 12 .

At the inlet duct 7 , a device for exhaust gas recirculation can be provided. If such a device is provided, the timing of the check valve 12 can be adjusted accordingly. The ventilation line 24 can advantageously be designed as a resonant system, where the unthrottled air metering by the check valve 12 optimizes. In addition, it is also possible to control the ventilation flow L3 via a further actuator, which is not shown in more detail here. After closing at time T3 ( FIG. 2), the energization of the coil 17 ′, which holds the valve in the closed position, is released and the actuating spring 19 pulls the valve plate 13 into the rest position of the check valve 12 . The opening movement can be supported by loading the coil 17 facing away from the valve plate. The opening of the check valve 12 takes place after the intake valve closes before the intake of the subsequent working cycle of the cylinder, when the intake valve is opened again.

In the embodiment of the invention shown in FIGS. 3 and 4, the check valve is analogous to those above Be descriptions to Figs. 5 configured to 7, wherein the discharge of the combustion air to BKM by a Abfüh approximately clip takes place of the inlet passage 7, the angle to the axis of motion of the valve lifter branches off from the valve chamber into which the valve plate 13 can be moved by the valve lifter bar.

FIGS. 8 and 9 show an alternative embodiment ei nes shutoff valve, which is particularly suitable for the fiction, modern method for unthrottled load control according to Fig. 4 and is switched over during the opening interval of the intake valve from the closed position to the geöff designated position. The adjustable United closure member of the check valve is formed as a hollow cylinder 28 , which cooperates with its outer surface with annularly arranged at approximately the same height inlet openings 27 to the inlet channel 7 . The check valve includes a Ven valve housing 25 , in which a cylindrical inner wall 26 defines an annular space 30 in which combustion air is guided for the BKM. The cylindrical inner wall 26 delimits the inlet channel 7 , wherein a flow connection between the inlet channel 7 and the combustion air leading Rin graum 30 is given by the inlet openings 27 provided on the circumference of the cylindrical inner wall 26 at about the same height.

To close the shut-off valve, the closing cylinder 28 is brought into overlap with the inlet openings 27 and the flow connection between the annular space 30 and the inlet channel 7 is thus blocked. In the present embodiment, the locking cylinder 28 is arranged on the outer surface of the cylindrical inner wall 26 longitudinally displaceable and movable over the inlet openings 27 until they are completely covered. Alternatively, the locking cylinder 28 can also be arranged rotatably and have inlet slots which can be brought into overlap with the inlet openings 27 in the inner wall 26 of the housing by rotating actuating movements. In the open position of the blocking valve according to FIG. 8, the longitudinally displaceable locking cylinder 28 releases the inlet openings 27 so that 27 air flows L can enter the inlet channel 7 through the inlet openings.

In the illustration according to FIG. 9, the Sperrven til is in the closed position, wherein the shutter cylinder 28, the inlet openings blocked 27th In the embodiment shown, the flow connection can be kept in the closed position without any significant Ven valve forces, since the pressure P in the annular space 30 acts independently of the actuating movement of the locking cylinder 28 . The check valve can thus be kept active against the negative pressure in the inlet channel 7 in the closed position without energy expenditure.

The lock cylinder 28 is preferably designed such that a small air gap between the inside of the lock cylinder 28 and the inlet openings 27 provided inner wall 26 of the housing 25 remains. In order to ensure low friction during the actuating movement of the lock cylinder, the lock cylinder 28 and / or the inner wall 26 of the housing 25 is coated with a sliding layer, for example made of Teflon.

In particular, the moving parts of the check valve expediently carried out with a low weight. Because the lock valve, in contrast to gas exchange valves, is called Ver is not exposed to combustion exhaust gases, the moveable Ren valve parts made of plastic or fiber composite materials or similar materials.

As an alternative to the electromagnetic actuator in be written embodiment can also be advantageous electrodynamic actuators with moving coils, hy draulic or pneumatic actuators for moving the ver closing member of the check valve are used. The white teren can switch the check valve by a Electric motor or a mechanical coupling with the crank shaft are controlled, the rotation of the crank wave over cams in the longitudinal movement of the closure member of the check valve is translated. The measurement of the fresh gases for the current operating point of the BKM takes place in this case at fixed opening angles of the Check valve by shifting the phase angle between the or the camshafts for driving the check valve.

Claims (15)

1. A method for unthrottled load control of a spark ignition BKM ( 1 ), each cylinder ( 10 ) for gas exchange with each work cycle combustion air is supplied via at least one inlet channel ( 7 ), which is temporarily opened by an inlet valve ( 3 ) during the work cycle is and wherein the air flow rate of the inlet channel ( 7 ) is adjusted accordingly to the operating load of the BKM ( 1 ) by temporarily opening and closing the inlet channel ( 7 ) in coordination with the control times of the inlet valve ( 3 ) for the gas exchange, characterized in that a check valve ( 12 ) in the inlet channel ( 7 ) with the inlet valve ( 3 ) between the open and closed switching state is switched over and the metering of the combustion air controls the operating load of the BKM ( 1 ) accordingly. 2. The method according to claim 1, characterized in that the check valve ( 12 ) at the beginning of the opening interval of the inlet valve ( 3 ) in the working cycle of the cylinder ( 10 ) is opened and during the opening interval of the inlet valve ( 3 ) is switched to the closed state , 3. The method according to claim 2, characterized in that the check valve ( 12 ) is closed during the opening actuating movement of the inlet valve ( 3 ). 4. The method according to claim 1, characterized in that the check valve ( 12 ) at the beginning of the opening interval of the inlet valve ( 3 ) during the working cycle of the cylinder ( 10 ) GE is closed and during the opening interval of the inlet valve ( 3 ) in the open state is switched. 5. The method according to claim 4, characterized in that the opening of the check valve ( 12 ) takes place during the closing movement of the inlet valve ( 3 ). 6. Device for unthrottled load control of a spark-ignition BKM ( 1 ) with per cylinder ( 10 ) at least one inlet channel ( 7 ), which can be released by an inlet valve for gas exchange during the work cycle of the respective cylinder ( 10 ), with one on the Air throughput of the inlet channel ( 7 ) acting actuator, which can be switched between the inlet channel ( 7 ) and a blocking position in coordination with the timing of the inlet valve ( 3 ) for the gas exchange sel during the working cycles of the cylinder ( 10 ), characterized in that that the actuator is a check valve ( 12 ) with a fast-switching United closure member ( 13 , 28 ). 7. The device according to claim 6, characterized in that the check valve ( 12 ) is designed as a tappet valve with a longitudinally movable valve tappet ( 14 ) by an actuator ( 15 ) which carries at its free end a valve plate ( 13 ) as a closure member. 8. The device according to claim 7, characterized by such a design of the check valve ( 12 ) that the valve plate ( 13 ) by moving the valve tappet ( 14 ) in the flow direction of the inlet channel ( 7 ) on a valve seat ( 16 ) can be placed. 9. The device according to claim 7, characterized by such a design of the check valve ( 12 ) that the valve plate ( 13 ) by moving the valve tappet ( 14 ) in the flow direction of the inlet channel ( 7 ) from a valve seat ( 16 ) can be opened opening. 10. The device according to claim 6, characterized in that the check valve has a hollow cylindrical closure member ( 28 ) which is arranged movably and closes in overlap with one or more on the circumference of the inlet channel ( 7 ) arranged inlet openings ( 27 ) for combustion air is. 11. The device according to claim 10, characterized in that the hollow cylindrical closure member ( 28 ) is arranged to be longitudinally displaceable and the section of the inlet duct ( 12 ) lying in the flow direction of the inlet duct ( 7 ) before the shut-off valve ( 12 ) has the section having the inlet openings ( 27 ) axially engages to form an annular space ( 30 ). 12. Device according to one of claims 6 to 11, characterized in that the closure member ( 13 , 28 ) by a return spring ( 19 ) held in its rest position and by the actuator ( 15 ) against the Fe derkraft the return spring ( 19 ) is movable , 13. Device according to one of claims 6 to 12, characterized in that the inlet channel ( 7 ) is provided with a ventilation device ( 24 ). 14. The apparatus according to claim 13, characterized in that the ventilation line ( 24 ) is connected to the exhaust line of the internal combustion engine ( 1 ). 15. Device according to one of claims 6 to 14, characterized in that the inlet channel ( 7 ) is provided with a device for exhaust gas recirculation.