High and low pressure EGR with a common valve housing

Abstract

A device of a system for air ducting of an internal combustion engine in a motor vehicle with a turbocharger arranged between an exhaust gas line and an intake line. The device includes a high pressure flow pathway with a valve branching from the exhaust gas line between the internal combustion engine and a turbine side of the turbocharger, a low pressure flow pathway with a valve branching in the flow direction of the exhaust gas downstream from the turbine side of the turbocharger, and an exhaust gas heat exchanger. A first flow pathway with a valve and a second flow pathway with a valve merge into a mouth region with a third flow pathway. At least one section of the high pressure flow pathway, the low pressure flow pathway, the flow pathways, and the exhaust gas heat exchanger are integrated inside a housing formed as a continuous compact unit.

Claims

1. An air ducting device for air ducting of an internal combustion engine in a motor vehicle having a turbocharger arranged between an exhaust gas line for the expansion of exhaust gas exiting the internal combustion engine and an intake line for compression of intake air to be delivered to the internal combustion engine, the air ducting device comprising: a housing; a high pressure flow pathway with a first valve, the high pressure flow pathway branching the intake line downstream from a compressor side of the turbocharger in a flow direction of the intake air to the exhaust gas line between the internal combustion engine and upstream from a turbine side of the turbocharger in a flow direction of the exhaust gas; a low pressure flow pathway with a second valve, the low pressure flow pathway branching from the exhaust gas line downstream from the turbine side of the turbocharger in the flow direction of the exhaust gas to the intake line upstream of the compressor side of the turbocharger in the flow direction of the intake air; a first flow pathway of the low pressure flow pathway branching the intake line upstream of the compressor side of the turbocharger in the flow direction of the intake air to a mouth region of the first flow pathway; a second flow pathway of the high pressure flow pathway having a third valve and extending from the first valve to the mouth region of the first flow pathway; a third flow pathway of the low pressure flow pathway having a fourth valve and extending from the second valve to the mouth region of the first flow pathway, the second flow pathway and the third flow pathway merging in the mouth region of the first flow pathway; and an exhaust gas heat exchanger, wherein at least a portion of each of the high pressure flow pathway, the low pressure flow pathway, the first flow pathway, the second flow pathway, the third flow pathway, and the exhaust gas heat exchanger is integrated within the housing.

2. The air ducting device according to claim 1, wherein a portion of the housing is formed as a continuous one-piece component.

3. The air ducting device according to claim 2, wherein at least one of the first valve, the second valve, the third valve, and the fourth valve is integrated within the housing.

4. The air ducting device according to claim 1, wherein the exhaust gas heat exchanger is arranged between and fluidly couples the second flow pathway to the third flow pathway.

5. The air ducting device according to Claim 1, wherein the exhaust gas heat exchanger is arranged between and fluidly couples the high pressure flow pathway to the low pressure flow pathway.

6. The air ducting device according to claim 1, wherein the high pressure flow pathway and the low pressure flow pathway merge at a merge region and each of the second flow pathway and the third flow pathway extends away from the merge region, and wherein the exhaust gas heat exchanger is arranged in the third flow pathway.

7. The air ducting device according to claim 1, wherein a fourth flow pathway branches from the intake line downstream from the compressor side of the turbocharger in the direction of flow of the intake air and extends to the mouth region of the first flow pathway, the fourth flow pathway including a fifth valve and the first flow pathway including a sixth valve.

8. The air ducting device according to claim 7, wherein each of the fifth valve and the sixth valve is integrated within the housing.

9. The air ducting device according to claim 1, wherein the first valve and the second valve are configured for simultaneous and joint actuation by a first actuator.

10. The air ducting device according to claim 9, wherein the third valve and the fourth valve are configured for simultaneous and joint actuation by a second actuator.

11. A method of operating a system for air ducting of an internal combustion engine in a motor vehicle, the system comprising a turbocharger arranged between an exhaust gas line for the expansion of exhaust gas exiting the internal combustion engine and an intake line for compression of intake air to be delivered to the internal combustion engine; the method comprising the steps of: providing an air ducting device comprising: a housing, a high pressure flow pathway with a first valve, the high pressure flow pathway branching from the exhaust gas line downstream from the internal combustion engine and upstream from a turbine side of the turbocharger in a flow direction of the exhaust gas to the intake line downstream from a compressor side of the turbocharger and upstream from the internal combustion engine in a flow direction of the intake air; a low pressure flow pathway with a second valve, the low pressure flow pathway branching from the exhaust gas line downstream from the turbine side of the turbocharger in the flow direction of the exhaust gas to the intake line upstream from the compressor side of the turbocharger in the flow direction of the intake air; a first flow pathway of the low pressure flow pathway having a third valve and branching from the intake line upstream of the compressor side of the turbocharger in the flow direction of the intake air to a mouth region of the first flow pathway; a second flow pathway of the high pressure flow pathway having a fourth valve and a third flow pathway of the low pressure flow pathway having a fifth valve, the second flow pathway extending from the first valve to the mouth region of the first flow pathway, the third flow pathway extending from the second valve to the mouth region of the first flow pathway, the second flow pathway and the third flow pathway merging together in the mouth region of the first flow pathway; a fourth flow pathway having a sixth valve and branching from the intake line downstream from the compressor side of the turbocharger in the direction of flow of the intake air and extending to the mouth region of the first flow pathway; an exhaust gas heat exchanger, wherein at least a portion of each of the high pressure flow pathway, the low pressure flow pathway, the first flow pathway, the second flow pathway, the third flow pathway, the fourth flow pathway, and the exhaust gas heat exchanger is integrated within the housing; and adjusting at least one of the first valve, the second valve, the third valve, the fourth valve, the fifth valve, and the sixth valve between an open position and a closed position to change an operational mode of the air ducting device.

12. The method according to claim 11, wherein the exhaust gas line includes an exhaust high pressure region extending from the internal combustion engine to the turbine side of the turbocharger and an exhaust low pressure region formed downstream from the turbine side of the turbocharger in the direction of flow of the exhaust gas and the intake line includes an intake high pressure region extending from the compressor side of the turbocharger to the internal combustion engine and an intake low pressure region formed upstream from the compressor side of the turbocharger in the direction of flow of the intake air.

13. The method according to claim 12, wherein the air ducting device is configured to be operational in each of the following operational modes: removal of the exhaust gas from the exhaust high pressure region and supplying of the exhaust gas to the intake low pressure region with cooling of the exhaust gas by the exhaust gas heat exchanger during a first operational mode; removal of the exhaust gas from the exhaust high pressure region and supplying of the exhaust gas to the intake low pressure region without cooling of the exhaust gas by the exhaust gas heat exchanger during a second operational mode; removal of the exhaust gas from the exhaust low pressure region and supplying of the exhaust gas to the intake low pressure region with cooling of the exhaust gas by the exhaust gas heat exchanger during a third operation mode; and removal of the exhaust gas from the exhaust low pressure region and supplying of the exhaust gas to the intake low pressure region without cooling of the exhaust gas by the exhaust gas heat exchanger during a fourth operational mode.

14. The method according to claim 13, wherein the air ducting device is further configured to be operational in each of the following operational modes: removal of the exhaust gas from the exhaust low pressure region and supplying of the exhaust gas to the intake high pressure region without cooling of the exhaust gas by the exhaust gas heat exchanger during a fifth operational mode; removal of the exhaust gas from both the exhaust high pressure region and the exhaust low pressure region and supplying of the exhaust gas to the intake low pressure region without cooling of the exhaust gas by the exhaust gas heat exchanger during a sixth operational mode; removal of the exhaust gas from both the exhaust high pressure region and the exhaust low pressure region and supplying of the exhaust gas to the intake low pressure region with cooling of the exhaust gas removed from the exhaust high pressure region by the exhaust gas heat exchanger during a seventh operational mode; and removal of the exhaust gas from both the exhaust high pressure region and the exhaust low pressure region and supplying of the exhaust gas to the intake low pressure region with cooling of the exhaust gas removed from the exhaust low pressure region by the exhaust gas heat exchanger during an eighth operational mode.

15. The method according to claim 12, wherein the air ducting device is configured to be operational in each of the following operational modes: removal of the exhaust gas from the exhaust high pressure region and supplying of the exhaust gas to the intake high pressure region with cooling of the exhaust gas by the exhaust gas heat exchanger during a first operational mode; removal of the exhaust gas from the exhaust high pressure region and supplying of the exhaust gas to the intake high pressure region without cooling of the exhaust gas by the exhaust gas heat exchanger during a second operational mode; and removal of the intake air from the intake low pressure region and supplying of the intake air to the intake high pressure region during a third operational mode.

16. The method according to claim 12, wherein the air ducting device is configured to be operational in a waste-gate operational mode wherein the exhaust gas is removed from the exhaust high pressure region and supplied to the exhaust low pressure region to bypass the turbine side of the turbocharger.

17. The method according to claim 16, wherein the waste-gate operational mode includes the first valve and the second valve each being adjusted to the open position and the third valve and the sixth valve each being adjusted to the closed position.

Description

DESCRIPTION OF THE DRAWINGS

(1) Further details, features and benefits of embodiments of the invention will emerge from the following specification of sample embodiments making reference to the accompanying figures. There are shown:

(2) FIG. 1: System for air ducting of an internal combustion engine with arrangements for recirculation of exhaust gas known from the prior art,

(3) FIGS. 2, 3: System for recirculation of exhaust gas of an internal combustion engine with a device for exhaust gas recirculation at high pressure or low pressure with four flow pathways and valves arranged in the flow pathways, as well as an exhaust gas heat exchanger,

(4) FIG. 4: Device for exhaust gas recirculation of a system per FIG. 2 with four flow pathways and valves arranged in the flow pathways, as well as an exhaust gas heat exchanger,

(5) FIG. 5: System from FIG. 2 with common actuations of two valves each time, arranged in the flow pathways, each by means of an actuator,

(6) FIG. 6: System from FIG. 5 with common actuation of the valves configured inside the high pressure flow pathway SHD and the low pressure flow pathway SND by means of an actuator,

(7) FIG. 7A, 7B: Actuator for actuation of two valves with a drive and adjustment elements in side view and top view,

(8) FIG. 7C: Actuator from FIG. 7B in connection with the valves,

(9) FIG. 7D: Representation of the stroke function of the actuator for control of the valves with the opening degree of the valves dependent on the angle of rotation of the adjustment elements,

(10) FIG. 8: System from FIG. 2 with a device for exhaust gas recirculation each time with a three-way valve instead of two valves arranged in the flow pathways,

(11) FIGS. 9, 10: Device for exhaust gas recirculation of a system per FIG. 8 with four flow pathways and two three-way valves arranged in the flow pathways as flap valves as well as the exhaust gas heat exchanger,

(12) FIG. 11: Device for exhaust gas recirculation of a system per FIG. 8 with four flow pathways and two three-way valves arranged in the flow pathways, the first three-way valve being configured as a flap valve and the second three-way valve as a rotary valve, as well as the exhaust gas heat exchanger,

(13) FIG. 12: System from FIG. 2 with a device for exhaust gas recirculation with a four-way valve instead of four individual valves arranged in the flow pathways,

(14) FIG. 13: Device for exhaust gas recirculation of a system per FIG. 12 with four flow pathways and a four-way valve configured as a rotary valve arranged between the flow pathways,

(15) FIGS. 14, 15: System for recirculation of exhaust gas of an internal combustion engine with a device for exhaust gas recirculation from high pressure or low pressure to low pressure with three flow pathways and valves arranged in two flow pathways as well as an exhaust gas heat exchanger, and

(16) FIG. 16: Device for exhaust gas recirculation of a system per FIG. 14 with flow pathways and valves arranged in flow pathways as well as an exhaust gas heat exchanger.

WRITTEN DESCRIPTION OF THE INVENTION

(17) FIGS. 2 and 3 each show a system 1a, 1b for recirculation of exhaust gas of an internal combustion engine 3 with a device for exhaust gas recirculation 19a, 19a at high pressure and/or low pressure with four flow pathways S1, S2, S3, S4 and valves 15, 16, 17, 18 arranged in the flow pathways S1, S2, S3, S4 as well as an exhaust gas heat exchanger 11.

(18) Through the intake line 8, fresh air as well as the exhaust gas is taken in from the surroundings across the compressor side of the turbocharger 5 in the flow direction 9 as combustion air for the internal combustion engine 3. The air, compressed by flowing through the compressor side of the turbocharger 5, is ducted across the charge air cooler 10 to the internal combustion engine 3 and distributed among the individual cylinders.

(19) The exhaust gas produced by the combustion is ducted through the exhaust gas line 4 across the turbine side of the turbocharger 5. Since the turbine side is mechanically coupled, for example by a shaft, to the compressor side of the turbocharger 5, the turbine drives the compressor so that the air throughput is increased or the intake work of the pistons of the internal combustion engine 3 is decreased. The exhaust gas is discharged into the surroundings in the flow direction 7 after passing through the turbine side of the turbocharger 5 and the devices 6a, 6b for aftertreatment of the exhaust gas.

(20) The exhaust gas line 4 and the intake line 8 are fluidically connected to each other across a device 19a, 19a for exhaust gas recirculation, the device 19a, 19a for exhaust gas recirculation being able to operate in the high pressure region and/or in the low pressure region.

(21) The device 19a, 19a for exhaust gas recirculation connects the exhaust gas line 4 in the flow direction 7 of the mass flow of exhaust gas upstream from the turbine side of the turbocharger 5 to the intake line 8 in the flow direction 9 of the intake mass air flow downstream from the charge air cooler 10 and thus downstream from the compressor side of the turbocharger 5 in the high pressure region as well as the exhaust gas line 4 in the flow direction 7 of the mass flow of exhaust gas downstream from the turbine side of the turbocharger 5 to the intake line 8 in the flow direction 9 of the intake mass air flow upstream from the compressor side of the turbocharger 5 in the low pressure region.

(22) The device 19a, 19a has the exhaust gas heat exchanger 11 for cooling the exhaust gas and for regulating the quantity and thus the dosage of the recirculated mass flow of the exhaust gas, a valve 14a configured inside the high pressure flow pathway SHD and a valve 14b configured inside the low pressure flow pathway SND.

(23) The exhaust gas heat exchanger 11 in the embodiment of the device 19a of the system 1a per FIG. 2 is arranged between the flow pathways S1 and S2. The flow pathways S1 and S2 extend from one of the valves 14a, 14b of the high pressure flow pathway SHD and the low pressure flow pathway SND, respectively, to a mouth region.

(24) Within each of the flow pathways S1 and S2 there is configured a valve 15, 16.

(25) In the embodiment of the device 19a of the system 1b per FIG. 3, unlike the embodiment per FIG. 2, the exhaust gas heat exchanger 11 is arranged inside the flow pathway S2 between the valve 16 and the mouth region. The high pressure flow pathway SHD and the low pressure flow pathway SND are merged together in the flow direction of the exhaust gas downstream from the valves 14a, 14b and travel as a common channel before the flow pathways S1, S2 branch off from the common channel.

(26) Extending from the mouth region in the flow direction of the exhaust gas in both the system 1a of FIG. 2 and in the system 1b of FIG. 3 are two additional flow pathways S3, S4, while the flow pathway S3 as a component of the high pressure flow pathway SHD empties between the charge air cooler 10 and the internal combustion engine 3 and the flow pathway S4 as a component of the low pressure flow pathway SND empties upstream from the compressor side of the turbocharger 5 into the intake line 8. A valve 17, 18 is also configured in each case inside the flow pathways S3 and S4.

(27) FIG. 4 shows a device 19a for exhaust gas recirculation of the system 1a per FIG. 2 with a housing 20a. In the housing 20a are integrated the valves 15, 16, 17, 18 arranged in the four flow pathways S1, S2, S3, S4, the valve 14a configured inside the high pressure flow pathway SHD and the valve 14b configured inside the low pressure flow pathway SND as well as the exhaust gas heat exchanger 11. The compact and one-piece/one-part or multiple-part housing 20a brings together all flow pathways S1, S2, S3, S4, the high pressure flow pathway SHD and the low pressure flow pathway SND and encompasses all the valves 14a, 14b, 15, 16, 17, 18.

(28) The valves 14a, 14b, arranged as the inlet for the exhaust gas to the device 19a, are configured each as a seat valve or a poppet valve and can move back and forth in an indicated lengthwise direction. The exhaust gas flowing into the device 19a either through the high pressure flow pathway SHD or the low pressure flow pathway SND can as needed be taken through the exhaust gas heat exchanger 11 or bypassing the exhaust gas heat exchanger 11 into the mouth region 21.

(29) The exhaust gas heat exchanger 11 is shown here as a U-flow heat exchanger, as an example.

(30) The valves 15, 16, 17, 18 arranged in the four flow pathways S1, S2, S3, S4 are each configured as a flap valve and can move about a pivoting axis in an indicated direction of rotation. According to an alternative embodiment, not represented, the valves 15, 16, 17, 18 can be configured as seat valves. In the representation of FIG. 4, all the valves 14a, 14b, 15, 16, 17, 18 are closed.

(31) The device 19a can be operated in the switching variants indicated in the following table. The flow pathways and the corresponding valves are designated with the reference symbols. The switch positions of the valves 14a, 14b, 15, 16, 17, 18 are indicated by c for closed and o for open.

(32) TABLE-US-00001 SHD SND S1 S2 S3 S4 Function 14a 14b 15 16 17 18 I Exhaust gas cooled to high pressure o c c o o c II Exhaust gas not cooled to high pressure o c o c o c III Exhaust gas cooled from high pressure to low pressure o c c o c o IV Exhaust gas not cooled from high pressure to low pressure o c o c c o V Exhaust gas cooled to low pressure c o o c c o VI Exhaust gas not cooled to low pressure c o c o c o VII Turbocharger 5 with air-divert/blow-off- function c c o o VIII Fresh air flow to the exhaust gas side c o o o c IX Turbocharger 5 with bypass/waste gate function o o c c X Exhaust gas not cooled from low pressure and high pressure o o o o c o to low pressure XI Exhaust gas cooled from low pressure and high pressure to o o c o c o low pressure, exhaust gas cooled to high pressure XII Exhaust gas cooled from low pressure and high pressure to o o o c c o low pressure, exhaust gas cooled to high pressure, exhaust gas cooled to low pressure XIII Turbocharger 5 with divert-air/blow-off function and o o c c o o turbocharger 5 with bypass/waste gate function

(33) By Function I the device 19a is operated as an arrangement for recirculation of exhaust gas in the high pressure region with cooling of the exhaust gas. The exhaust gas is taken through the high pressure flow pathway SHD into the device 19a, through the exhaust gas heat exchanger 11 and the opened valve 16 into the mouth region 21 and taken away through the flow pathway S3 to the internal combustion engine 3.

(34) By Function II the device 19a is operated as an arrangement for recirculation of exhaust gas in the high pressure region without cooling of the exhaust gas. The exhaust gas is taken through the high pressure flow pathway SHD into the device 19a, bypassing the exhaust gas heat exchanger 11, and through the opened valve 15 into the mouth region 21 and taken away through the flow pathway S3 to the internal combustion engine 3.

(35) By Function III the device 19a is operated as an arrangement for removal of exhaust gas in the high pressure region with cooling of the exhaust gas and supplying of the exhaust gas in the low pressure region. The exhaust gas is taken through the high pressure flow pathway SHD into the device 19a, through the exhaust gas heat exchanger 11 and the opened valve 16 into the mouth region 21 and taken away through the flow pathway S4 to the compressor side of the turbocharger 5.

(36) By Function IV the device 19a is operated as an arrangement for removal of exhaust gas in the high pressure region without cooling of the exhaust gas and supplying of the exhaust gas in the low pressure region. The exhaust gas is taken through the high pressure flow pathway SHD into the device 19a, bypassing the exhaust gas heat exchanger 11, and through the opened valve 15 into the mouth region 21 and taken away through the flow pathway S4 to the compressor side of the turbocharger 5.

(37) By Function V the device 19a is operated as an arrangement for recirculation of exhaust gas in the low pressure region with cooling of the exhaust gas. The exhaust gas is taken through the low pressure flow pathway SND into the device 19a, through the exhaust gas heat exchanger 11 and the opened valve 15 into the mouth region 21 and taken away through the flow pathway S4 to the compressor side of the turbocharger 5.

(38) By Function VI the device 19a is operated as an arrangement for recirculation of exhaust gas in the low pressure region without cooling of the exhaust gas. The exhaust gas is taken through the low pressure flow pathway SND into the device 19a, bypassing the exhaust gas heat exchanger 11, and through the opened valve 16 into the mouth region 21 and taken away through the flow pathway S4 to the compressor side of the turbocharger 5.

(39) By Function VII the device 19a is operated only as a divert-air valve. The mass air flow taken in from the surroundings in the flow direction 9 bypasses the compressor side of the turbocharger 5 and the charge air cooler 10 and goes to the internal combustion engine 3. No exhaust gas is mixed in with the mass air flow taken in from the surroundings.

(40) By Function VIII the device 19a is operated such that a fresh air flow is ducted to the exhaust gas side. The mass air flow taken in from the surroundings in the flow direction 9 is compressed upon flowing through the compressor side of the turbocharger 5 and taken across the charge air cooler 10 through the opened valve 17 into the device 19a and also through the opened valve 16 and the opened valve 14b bypassing the exhaust gas heat exchanger 11 to the device 6b for aftertreatment of the exhaust gas. Thus, the fresh air is taken in the flow direction 7 of the mass flow of exhaust gas upstream from the device 6b, in order to improve the aftertreatment of the exhaust gas, for example by further oxidation of unburned fuel. Function VIII can also be used as a device 6b for aftertreatment of the exhaust gas in the cold start phase of the internal combustion engine 3 for faster heat-up of a catalyst.

(41) By Function IX the device 19a is operated only as a bypass or waste gate valve. The exhaust gas emerging in the flow direction 7 from the internal combustion engine 3 is taken past the turbine side of the turbocharger 5.

(42) By Function X the device 19a is operated as an arrangement for removal of exhaust gas in the low pressure region and in the high pressure region without cooling of the exhaust gas and supplying of the exhaust gas in the low pressure region. Exhaust gas is taken both through the low pressure flow pathway SND and through the high pressure flow pathway SHD into the device 19a, bypassing the exhaust gas heat exchanger 11, and through the opened valve 15, 16 of the flow pathways S1, S2 into the mouth region 21 and taken away through the flow pathway S4 to the compressor side of the turbocharger 5. The valves 15, 16 can also be adjusted to achieve favorable pressure gradients for the ducting of the exhaust gas in regard to the distribution of the exhaust gas through the low pressure region and the high pressure region.

(43) By Function XI the device 19a is operated as an arrangement for removal of exhaust gas in the low pressure region and in the high pressure region with cooling of the exhaust gas from the high pressure region and supplying of the exhaust gas in the low pressure region. Exhaust gas is taken into the device 19a through both the low pressure flow pathway SND and the high pressure flow pathway SHD. The exhaust gas taken in through the high pressure flow pathway SHD is taken through the exhaust gas heat exchanger 11, thereby cooled, and then mixed with the exhaust gas brought in through the low pressure flow pathway SND and taken through the opened valve 16 into the mouth region 21 and taken away through the flow pathway S4 to the compressor side of the turbocharger 5.

(44) By Function XII the device 19a is operated as an arrangement for removal of exhaust gas in the low pressure region and in the high pressure region with cooling of the exhaust gas from the low pressure region and supplying of the exhaust gas in the low pressure region. Exhaust gas is taken both through the low pressure flow pathway SND and through the high pressure flow pathway SHD into the device 19a. The exhaust gas taken in through the low pressure flow pathway SND is taken through the exhaust gas heat exchanger 11, thereby cooled, and then mixed with the exhaust gas brought in through the high pressure flow pathway SHD and taken through the opened valve 15 into the mouth region 21 and taken away through the flow pathway S4 to the compressor side of the turbocharger 5.

(45) By Function XIII the device 19a is operated as a divert-air valve and as a bypass or waste gate valve. On the one hand, the mass air flow taken in from the surroundings in the flow direction 9 is taken past the compressor side of the turbocharger 5 and the charge air cooler 10 to the internal combustion engine 3 and on the other hand the exhaust gas emerging in the flow direction 7 from the internal combustion engine 3 is taken past the turbine side of the turbocharger 5. No exhaust gas is mixed in with the mass air flow taken in from the surroundings.

(46) FIG. 5 shows the system 1a for recirculation of exhaust gas of an internal combustion engine 3 from FIG. 2 with the device for exhaust gas recirculation 19a at high pressure or low pressure with the four flow pathways S1, S2, S3, S4 and the valves 15, 16, 17, 18 arranged therein, as well as the exhaust gas heat exchanger 11 with common actuations for every two valves 15, 16, 17, 18 arranged in the flow pathways S1, S2, S3, S4 each by means of an actuator 22, 23.

(47) The valves 15 and 16 arranged inside the flow pathways S1 and S2 and the valves 17 and 18 arranged inside the flow pathways S3 and S4 are configured to be driven as so-called double valves each time with a single actuator 22, 23. The actuator 22 serves to control the valves 15, 16 and the actuator 23 serves to control the valves 17, 18.

(48) The jointly moved valves 15 and 16 and the jointly moved valves 17 and 18 can take up any given position between open and closed independently of each other.

(49) FIG. 6 shows the system 1a of FIG. 5 additionally with a common actuation of the valves 14a, 14b configured inside the high pressure flow pathway SHD and the low pressure flow pathway SND by means of an actuator 24.

(50) The valves 14a and 14b are also configured to be driven as so-called double valves with the common actuator 24. The jointly moved valves 14a and 14b once again can take up any given position between open and closed independently of each other.

(51) FIGS. 7A and 7B show an actuator 22, 23, 24 as a valve drive for the actuation of two valves with a drive 25 and two adjustment elements 26, 27 in a side view and in a top view.

(52) The drive 25 can be configured with a gearing and is mechanically connected by a shaft to the adjustment elements 26, 27, so that a turning of the shaft produces a turning of the adjustment elements 26, 27.

(53) The adjustment elements 26, 27 have a round or rounded shape and are arranged eccentrically to the shaft, spaced away from the shaft in the lengthwise direction and also rotated relative to each other about the axis of the shaft.

(54) FIG. 7C shows the actuator per FIG. 7B with the two adjustment elements 26, 27 each connected to a valve 14a, 15, 17 and 14b, 16, 18. Thanks to the arrangement of the adjustment elements 26, 27 rotated differently about the axis of the shaft and eccentrically to the shaft, the disks of the valves 14a, 15, 17 and 14b, 16, 18 are lifted and lowered differently and thus the valves 14a, 15, 17 and 14b, 16, 18 are opened and closed differently.

(55) FIG. 7D shows the stroke function of the actuators 22, 23, 24 for the control of the valves 14a, 15, 17 and 14b, 16, 18 with the degree of opening of the valves 14a, 15, 17 and 14b, 16, 18 depending on the angle of rotation of the adjustment elements 26, 27. The adjustment elements 26, 27 have external shapes or contours fashioned in the radial direction with which the following stroke functions can be executed upon rotation of the adjustment elements 26, 27.

(56) Upon rotation of the shaft and thus the adjustment elements 26, 27 in the range from 0, the valve 14a, 15, 17 is activated to open, while the valve 14b, 16, 18 remains closed.

(57) Upon rotation of the shaft in the range between around 100 and around 215, the valve 14a, 15, 17 is activated to close, while the valve 14b, 16, 18 is activated to open. In an intermediate range from 100 to 215 with the valve 14a, 15, 17 and the valve 14b, 16, 18 both valves are at least partly opened.

(58) Upon rotation of the shaft in the range between around 215 and around 320, the valve 14b, 16, 18 is activated to close, while the valve 14a, 15, 17 remains closed. In the range from 320 to 360 or 0 both valves 14a, 15, 17 and 14b, 16, 18 are closed.

(59) Besides the design of the actuators per FIG. 7A to 7C, other systems are also conceivable, such as linear, electrical or hydraulic ones. The systems can be used for only one or two or three valve pairs.

(60) FIG. 8 shows the system 1a from FIG. 2 with a device 19b, 19c, 19d for exhaust gas recirculation each time with a three-way valve 28, 29, 30 instead of the two valves 15, 16, 17, 18 arranged in the flow pathways S1, S2, S3, S4. The first three-way valve 28 replaces the valves 15, 16 from the flow pathways S1, S2, while the second three-way valve 29, 30 replaces the valves 17, 18 from the flow pathways S3, S4.

(61) The embodiments of a device 19b, 19c, 19d of the system 1a per FIG. 8 are shown in FIGS. 9 to 11. Due to the configuration of the three-way valves 28, 29, the possible functions which require each time two closed flow pathways S1 and S2 or S3 and S4 are limited as compared to the configuration of the device 19a per FIG. 4.

(62) FIGS. 9 and 10 show devices 19b, 19c for exhaust gas recirculation of system 1a per FIG. 8 each time with a housing 20b, 20c. The housings 20b, 20c integrate the three-way valves 28, 29 arranged in the four flow pathways S1, S2, S3, S4 and configured as flap valves, the valve 14a configured inside the high pressure flow pathway SHD and the valve 14b configured inside the low pressure flow pathway SND as well as the exhaust gas heat exchanger 11. The compact and single-piece/single-part or multiple-part housings 20b, 20c bring together all flow pathways S1, S2, S3, S4, the high pressure flow pathway SHD and the low pressure flow pathway SND, and encompass all valves 14a, 14b, 28, 29.

(63) The valves 14a, 14b arranged as the inlet of the exhaust gas into the device 19b, 19c are once again each configured as a seat valve or a poppet valve and can move back and forth in the indicated lengthwise direction. The exhaust gas flowing into the device 19b, 19c either through the high pressure flow pathway SHD or the low pressure flow pathway SND can be taken as needed through the exhaust gas heat exchanger 11 or bypassing the exhaust gas heat exchanger 11 into the mouth region 21.

(64) The exhaust gas heat exchanger 11 once again is configured as a U-flow heat exchanger as an example.

(65) The three-way valves 28, 29 arranged in the four flow pathways S1, S2, S3, S4 can move about an axis of rotation in a direction indicated each time. In the representations of FIGS. 9 and 10, the valves 14a and 14b as well as the flow pathways S1 and S3 are closed.

(66) The three-way valves 28, 29 of the device 19b per FIG. 9 and in the device 19c per FIG. 10 are able to flip between two end positions, the axes of rotation being arranged each time at the edge of the mouth region 21 and between the two mouths of the flow pathways S1, S2 or S3, S4 into the mouth region 21.

(67) The devices 19b, 19c can also be operated basically in the switching variants listed in the table given above for the device 19a for exhaust gas recirculation per FIG. 4. However, the devices 19b, 19c cannot be operated with the functions IX and XIII, since in functions IX and XIII the two flow pathways S1 and S2 or S3 and S4 are closed each time, which cannot be accomplished with the three-way valves 28, 29.

(68) FIG. 11 shows a device 19d for exhaust gas recirculation of the system 1a per FIG. 8 with a housing 20d. In the housing 20d are integrated the three-way valve 28 arranged in the two flow pathways S1, S2 and configured as a flap valve, the three-way valve 30 arranged in the two flow pathways S3, S4 and configured as a rotary valve, the valve 14a configured inside the high pressure flow pathway SHD and the valve 14b configured inside the low pressure flow pathway SND, as well as the exhaust gas heat exchanger 11. The compact and single-piece/single-part or multiple-part housing 20d brings together all flow pathways S1, S2, S3, S4, the high pressure flow pathway SHD and the low pressure flow pathway SND, and encompasses all valves 14a, 14b, 28, 30.

(69) The valves 14a, 14b arranged as the inlet of the exhaust gas into the device 19d are, as in the previously mentioned embodiments, each configured as a seat valve or a poppet valve and can move back and forth in the indicated lengthwise direction. The exhaust gas flowing into the device 19d either through the high pressure flow pathway SHD or the low pressure flow pathway SND can be taken as needed through the exhaust gas heat exchanger 11 or bypassing the exhaust gas heat exchanger 11 into the mouth region 21.

(70) The exhaust gas heat exchanger 11, as in the previously mentioned embodiments, is configured as a U-flow heat exchanger as an example.

(71) The three-way valves 28, 30 arranged in the four flow pathways S1, S2, S3, S4 can move about an axis of rotation in a direction indicated each time. In the representations of FIG. 11, the valves 14a and 14b as well as the flow pathways S1, S3 and S4 are closed.

(72) The three-way valve 28 is able to flip between two end positions, the axis of rotation being arranged within the mouth region 21 and between the two emptying points of the flow pathways S1, S2 into the mouth region 21. The three-way valve 30 is able to turn between two end positions, the axis of rotation being arranged within the mouth region 21, preferably symmetrically to the two end positions of the flow pathways S3, S4.

(73) The device 19d can also be operated basically in the switching variants listed in the table given above for the device 19a for exhaust gas recirculation per FIG. 4. However, the device 19d cannot be operated with the function XIII, since in function XIII the two flow pathways S1 and S2 are closed, which is not possible with the three-way valve 28.

(74) FIG. 12 shows the system 1a from FIG. 2 with a device 19e for exhaust gas recirculation with a four-way valve 31 instead of the four valves 15, 16, 17, 18 arranged in the flow pathways S1, S2, S3, S4. The four-way valve 31 is this arranged between the flow pathways S1, S2, S3, S4.

(75) FIG. 13 shows a device 19e for exhaust gas recirculation of the system 1a per FIG. 12 with a housing 20e. In the housing 20e are integrated the four-way valve 31 arranged between the flow pathways S1, S2, S3, S4 and configured as a central rotary valve, the valve 14a configured within the high pressure flow pathway SHD and the valve 14b configured within the low pressure flow pathway SND, as well as the exhaust gas heat exchanger 11. The compact and single-piece/single-part or multiple-part housing 20e brings together all flow pathways S1, S2, S3, S4, the high pressure flow pathway SHD and the low pressure flow pathway SND, and encompasses all valves 14a, 14b, 31.

(76) The valves 14a, 14b arranged as the inlet of the exhaust gas into the device 19e are, as in the previously mentioned embodiments, each configured as a seat valve or a poppet valve and can move back and forth in the lengthwise direction. The exhaust gas flowing into the device 19e either through the high pressure flow pathway SHD or the low pressure flow pathway SND can be taken as needed through the exhaust gas heat exchanger 11 or bypassing the exhaust gas heat exchanger 11.

(77) The exhaust gas heat exchanger 11, as in the previously mentioned embodiments, is configured as a U-flow heat exchanger as an example.

(78) The four-way valve 31 arranged between the four flow pathways S1, S2, S3, S4 can move about an axis of rotation in the indicated directions. In the representation of FIG. 13, the valves 14a and 14b as well as the flow pathways S2 and S3 are closed. The flow pathways S1 and S4 are opened.

(79) The four-way valve 31 is configured with an adjustment element which is round in cross section and able to turn about the axis of rotation. The adjustment element has a through opening, which extends from a first end with a uniform cross section and has a cross section widening toward the second end. The cross section of the through opening can also widen continuously from the first end to the second end.

(80) The cross sections at the ends of the continuous opening correspond to the embodiments of the flow pathways S1, S2, S3, S4 within the housing 20e, that is, to the arrangements and cross sections of the flow pathways S1, S2, S3, S4 in the region of the adjustment element, such that the flow pathways S1, S2, S3, S4 can be opened or closed according to the functions listed in the above given table.

(81) Thus, the device 19e can be operated in all of the switching variants listed in the table indicated above for the device 19a for exhaust gas recirculation per FIG. 4.

(82) FIGS. 14 and 15 show systems 1c, 1d for recirculation of exhaust gas of an internal combustion engine 3 with a device 19f, 19f for exhaust gas recirculation from high pressure or low pressure to low pressure with three flow pathways S1, S2, S4 and valves 15, 16 arranged in the two flow pathways S1, S2 as well as an exhaust gas heat exchanger 11.

(83) The exhaust gas line 4 and the intake line 8 are fluidically joined together via the device 19f, 19f for exhaust gas recirculation, the device 19f, 19f for exhaust gas recirculation being able to receive exhaust gas from the high pressure region and/or the low pressure region and the exhaust gas is taken to the fresh air in the low pressure region. As compared to the embodiments per FIGS. 2 and 3, the devices 19f, 19f have no flow pathway S3 as a connection to the high pressure side of the intake region between the compressor side of the turbocharger 5 and the internal combustion engine 3. Thus, the valves 17, 18 of the flow pathways S3, S4 are also eliminated.

(84) The device 19f, 19f for exhaust gas recirculation connects the exhaust gas line 4 in the flow direction 7 of the mass flow of exhaust gas upstream from the turbine side of the turbocharger 5 and downstream from the turbine side of the turbocharger 5 in the high pressure region to the intake line 8 in the flow direction 9 of the intake mass air flow upstream from the compressor side of the turbocharger 5 in the low pressure region.

(85) The device 19f, 19f has the exhaust gas heat exchanger 11 for cooling the exhaust gas and for regulating the quantity and thus the dosage of the recirculated mass flow of exhaust gas, a valve 14a configured inside the high pressure flow pathway SHD, and a valve 14b configured inside the low pressure flow pathway SND.

(86) The exhaust gas heat exchanger 11 in the embodiment of the device 19f of system 1c per FIG. 14 is arranged between the flow pathways S1 and S2. The flow pathways S1 and S2 extend each from one of the valves 14a, 14b of the high pressure flow pathway SHD or the low pressure flow pathway SND up to a mouth region. Each time a valve 15, 16 is configured within the flow pathways S1 and S2.

(87) In the embodiment of the device 19f of the system 1d per FIG. 15, unlike the embodiment per FIG. 14, the exhaust gas heat exchanger 11 is arranged inside the flow pathway S2 between the valve 16 and the mouth region. The high pressure flow pathway SHD and the low pressure flow pathway SND are brought together in the flow direction of the exhaust gas downstream from the valves 14a, 14b and run as a common channel before the flow pathways S1, S2 branch off from the common channel.

(88) In each case a flow pathway S4 extends from the mouth region in the flow direction of the exhaust gas both in the system 1c from FIG. 14 and in the system 1d from FIG. 15, with the flow pathway S4 as a component of the low pressure flow pathway SND emptying into the intake line 8 upstream from the compressor side of the turbocharger 5.

(89) FIG. 16 shows a device 19f for exhaust gas recirculation of the system 1c per FIG. 14 with a housing 20f. In the housing 20f are integrated the valves 15, 16 arranged in the flow pathways S1, S2, the valve 14a configured inside the high pressure flow pathway SHD and the valve 14b configured inside the low pressure flow pathway SND as well as the exhaust gas heat exchanger 11. The compact and single-piece/single-part or multiple-part housing 20f brings together all flow pathways S1, S2, S4, the high pressure flow pathway SHD and the low pressure flow pathway SND, and encompasses all valves 14a, 14b, 15, 16.

(90) The valves 14a, 14b arranged as the inlet of the exhaust gas into the device 19f are each configured as a seat valve or a poppet valve and can move back and forth in an indicated lengthwise direction. The exhaust gas flowing into the device 19f either through the high pressure flow pathway SHD or the low pressure flow pathway SND can be taken as needed through the exhaust gas heat exchanger 11 or bypassing the exhaust gas heat exchanger 11.

(91) The exhaust gas heat exchanger 11, as in the previously mentioned embodiments, is configured as a U-flow heat exchanger as an example.

(92) Regardless of the different embodiments, the valve 14a of the high pressure flow pathway SHD and the valve 14b of the low pressure flow pathway SND can be configured with an actuator 24 for simultaneous and joint actuation.

(93) The valves 15, 16 arranged in the flow pathways S1, S2 are configured each time as a flap valve and can move about an axis of rotation in an indicated direction. According to an alternative embodiment, not shown, the valves 15, 16 are configured as a seat valve or poppet valve. In the representation of FIG. 16, all valves 14a, 14b, 15, 16 are closed.

(94) Only the functions I, II, VII and XIII of the embodiment of the device 19a per FIG. 4 as listed in the above given table cannot be implemented with the device 19f per FIG. 14, primarily because the flow pathway S3 is not configured as a connection of the device 19f to the high pressure region.

LIST OF REFERENCE SYMBOLS

(95) 1a, 1b, 1c, 1d, 1 System for air ducting 2a Arrangement for exhaust gas recirculation, high pressure 2b Arrangement for exhaust gas recirculation, low pressure 3 Internal combustion engine 4 Exhaust gas line 5 Turbocharger 6a, 6b Device for aftertreatment of exhaust gas 7 Flow direction of exhaust gas mass flow 8 Intake line 9 Flow direction of intake mass air flow 10 Charge air cooler 11, 11a, 11b Exhaust gas heat exchanger 12a, 12b Bypass 13a, 13b Bypass valve 14a, 14a Valve high pressure 14b, 14b Valve low pressure 15 Valve flow pathway S1 16 Valve flow pathway S2 17 Valve flow pathway S3 18 Valve flow pathway S4 19a, 19a, 19b, 19c Device for exhaust gas recirculation 19d, 19e, 19f, 19f Device for exhaust gas recirculation 20a, 20b, 20c Housing 20d, 20e, 20f Housing 21 Mouth region 22, 23, 24 Actuator 25 Drive 26, 27 Adjustment element 28, 29 Three-way valve 30 Three-way valve 31 Four-way valve S1, S2, S3, S4 Flow pathways SHD High pressure flow pathway SND Low pressure flow pathway