Intake pipe for a combustion engine

1. An intake pipe for a combustion engine, comprising

a housing ( 1 ) having a feed ( 2 ) for compressed air,

a heat exchanger ( 8 ), which is arranged within a main duct ( 4 ) in the housing ( 1 ) and through which the air can flow for heat exchange with a fluid, and

a bypass duct ( 5 ), which is separated from the main duct ( 4 ) at least sectionwise and has at least one control element ( 7 ) to enable the air fed in to bypass the heat exchanger ( 8 ) in an adjustable manner,

wherein

an engine-side end of the bypass duct ( 5 ) is at a short distance from an opening ( 11 ) of an inlet valve ( 10 ) of the combustion engine, which distance is still relevant to the flow wherein the distance is no more than about seven times a diameter of the inlet valve ( 10 ), wherein a flow cross section of the bypass duct ( 5 ) is no less than about 10% of a flow cross section of the main duct ( 4 ), and wherein the flow cross section of the bypass duct ( 5 ) is no more than about 60% of a flow cross section of the main duct ( 4 ), and further wherein the control element ( 7 ) is formed as a double flap ( 7 a , 7 b ) wherein a first flap ( 7 a ) of the double flap is positioned at an angle from a second flap of the double flap of less than 90°, and wherein the double flap is movable between a part load position wherein the first flap closes the main duct and the second flap opens the bypass duct, and a full load position wherein the first flap opens the main duct and the second flap closes the bypass duct.

2. The intake pipe as claimed in claim 1 , wherein the bypass duct ( 5 ) is designed as a tumble or swirl duct of the intake pipe.

3. The intake pipe as claimed in claim 1 , wherein the bypass duct ( 5 ) ends immediately ahead of a curved wall surface ( 9 a ) of an inlet region ( 9 ) of the combustion engine.

4. The intake pipe as claimed in claim 1 , wherein the bypass duct ( 5 ) is arranged above the main duct ( 4 ) in relation to an opening plane of the inlet valve ( 10 ).

5. The intake pipe as claimed in claim 1 , wherein the bypass duct ( 5 ) is arranged below the main duct ( 4 ) in relation to an opening plane of the inlet valve ( 10 ).

6. The intake pipe as claimed in claim 1 , wherein a masking structure ( 14 ) is provided in the end region of the bypass duct ( 5 ).

7. The intake pipe as claimed in claim 1 , wherein the main duct ( 4 ) is separated from the bypass duct ( 5 ) by means of a dividing wall ( 6 ) arranged in the housing.

8. The intake pipe as claimed in claim 1 , wherein, at least sectionwise, the bypass duct ( 5 ) is designed as a separate pipe conduit from the main duct ( 4 ).

9. The intake pipe as claimed in claim 1 , wherein the bypass duct ( 5 ) is designed, as regards its length, as an oscillation tube for the generation of resonance-type pressure charging, in an engine speed range between about 1000 and about 3000 revolutions per minute.

10. The intake pipe as claimed in claim 1 , wherein the housing ( 1 ) is constructed substantially from a plastic.

11. The intake pipe as claimed in claim 1 , wherein the control element ( 7 ) is arranged after the heat exchanger ( 8 ) in the direction of flow of the air.

12. The intake pipe as claimed in claim 11 , wherein the control element ( 7 ) is arranged in a region ( 1 b ) of the intake pipe which is separated in relation to different cylinders.

13. The intake pipe as claimed in claim 1 , wherein the control element ( 7 ) is adjustable in multiple stages or in an infinitely variable manner for the variably adjustable distribution of the air flow between the main duct ( 4 ) and the bypass duct ( 5 ).

14. The intake pipe as claimed in claim 1 , wherein, in one operating mode, the air flows through both the main duct ( 4 ) and at least a part of the bypass duct ( 5 ) which is arranged downstream of the heat exchanger ( 8 ).

15. The intake pipe as claimed in claim 1 , wherein a throttle valve ( 3 ) is arranged in the intake pipe.

16. The intake pipe as claimed in claim 1 , wherein the heat exchanger ( 8 ) is connected to a low-temperature cooling circuit.

17. The intake pipe as claimed in claim 1 , wherein the heat exchanger ( 8 ) is designed as an evaporator of a refrigeration circuit.

18. The intake pipe as claimed in claim 1 , wherein a flow of the fluid through the heat exchanger ( 8 ) can be controlled in an adjustable manner.

19. The intake pipe as claimed in claim 1 , wherein the control element ( 7 ) is connected to an actuator ( 18 , 19 , 20 ).

20. The intake pipe as claimed in claim 19 , wherein the actuator comprises a pressure cell ( 19 , 20 ).

21. The intake pipe as claimed in claim 19 , wherein the actuator has an electric drive ( 18 ).

22. The intake pipe as claimed in claim 1 , wherein at least one sensor for monitoring the position of the control element ( 7 ) is provided.

23. The intake pipe as claimed in claim 1 , wherein a feed ( 15 , 16 , 17 ) for recirculated exhaust gas is arranged on the intake pipe.

24. The intake pipe as claimed in claim 23 , wherein the feed ( 15 , 17 ) takes place separately into the bypass duct and/or the main duct.

25. The intake pipe as claimed in claim 23 , wherein the feed ( 16 ) takes place simultaneously into the bypass duct and the main duct.

26. The intake pipe as claimed in claim 23 , wherein the feed ( 15 , 16 , 17 ) takes place downstream of the heat exchanger.

27. The intake pipe as claimed in claim 23 , wherein the feed takes place upstream of the heat exchanger.

28. The intake pipe as claimed in claim 1 , wherein a division between the bypass duct ( 5 ) and the main duct ( 4 ) is continued within a cylinder head of the combustion engine.

29. The intake pipe as claimed in claim 28 , wherein the division is constructed at least in part as a dividing wall which projects beyond a connection plane (B) on the cylinder-head side and into the cylinder head.

30. The intake pipe as claimed in claim 28 , wherein the division is constructed as a dividing member which is fixed in an inlet region ( 9 ) of the cylinder head.

31. The intake pipe as claimed in claim 1 , wherein the distance is no more than about four times a diameter of the inlet valve ( 10 ).

32. The intake pipe as claimed in claim 10 , wherein the housing ( 1 ) is constructed substantially from a glass-reinforced polyamide.

33. The intake pipe as claimed in claim 1 , wherein the double flap is provided with reinforcing ribs ( 7 c ).

34. The intake pipe as claimed in claim 1 , wherein the first flap and the second flap are connected by reinforcing ribs ( 7 c ).

35. The intake pipe as claimed in claim 1 , wherein the double flap is pivotable around a pivot point ( 7 d ) positioned at an inlet end side of the dividing wall ( 6 ).