PISTON ENGINE

• US 20100242472A1
• Filed: 09/03/2008
• Published: 09/30/2010
• Est. Priority Date: 09/05/2007
• Status: Active Grant

• Current Assignee: Mahle International GmbH (MAHLE-STIFTUNG GmbH)
• Original Assignee: Mahle International GmbH (MAHLE-STIFTUNG GmbH)
• Inventors: Wieske, Peter, Senjic, Sascha, Elsässer, Alfred, Hoffmann, Hermann
• Granted Patent: US 8,857,177 B2
• Time in Patent Office: Days
• US Class Current: 60/605.100
• CPC Class Codes: F01L 1/047 Camshafts
• CPC Class Codes: F01L 1/267 with means for varying the timing or the lift of the valves
• CPC Class Codes: F01L 1/34413 using composite camshafts, e.g. with cams being able to move relative to the camshaft
• CPC Class Codes: F01L 2001/0473 Composite camshafts, e.g. with cams or cam sleeve being able to move relative to the inner camshaft or a cam adjusting rod
• CPC Class Codes: F02B 29/083 Cyclically operated valves disposed upstream of the cylinder intake valve, controlled by external means
• CPC Class Codes: F02B 37/20 by increasing exhaust energy, e.g. using combustion chamber by after-burning using an auxiliary combustion chamber supplied by charging air F02B37/166
• CPC Class Codes: F02D 13/0249 changing the valve timing only
• CPC Class Codes: F02D 13/0257 Independent control of two or more intake or exhaust valves respectively, i.e. one of two intake valves remains closed or is opened partially while the other is fully opened
• CPC Class Codes: F02D 37/02 one of the functions being ignition
• CPC Class Codes: F02D 41/0007 for control of turbo-charged or super-charged engines control of the pumps per se F02B37/12
• CPC Class Codes: F02D 41/10 for acceleration
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

A piston engine, having at least one cylinder that includes at least a first and a second discharge valve and a double overhead camshaft for controlling the first and a second discharge valves. The double overhead camshaft includes both an inner shaft, which has at least one first cam for controlling the first discharge valve, and an outer shaft that is coaxial to the first inner shaft and has at least one second cam for controlling the second discharge valve. The inner shaft and the outer shaft are rotationally adjustable relative to one another changing the discharge time frame of the discharge valves.

Claims

1. A piston engine, comprising:

at least one cylinder that has at least a first discharge valve and a second discharge valve; and

a double overhead camshaft for controlling the first and a second discharge valves,

wherein the double overhead camshaft includes an inner shaft, which has at least one first cam for controlling the first discharge valve, and an outer shaft that is coaxial to said first inner shaft and has at least one second cam for controlling the second discharge valve, and

wherein the inner shaft and the outer shaft are rotationally adjustable relative to one another to change the discharge timing of the first and second discharge valves.

2. The piston engine as specified in claim 1, further comprising:

an exhaust gas turbocharger having a turbine arranged in an exhaust-gas line of the piston engine; and

a control device, wherein the control device controls an adjusting device for rotational adjustment of a relative rotational position between the inner and outer shafts, and

the control device shifts to at least one of advance and retard the opening time of at least one of the first discharge valve and the second discharge valve to accelerate the turbine.

3. The piston engine as specified in claim 2, wherein the control device adjusts the opening time of the first and second discharge valves in a range approximately between 30% to 90% of an expansion stroke of a stroke-adjustable piston in the at least one cylinder to accelerate the turbine.

4. The piston engine as specified in claim 3, wherein the control device synchronously actuates the first and second discharge valves to an open position.

5. The piston engine as specified in claim 2, wherein the control device actuates at least one of the first and second discharge valves to an open position earlier than the unopened first or second discharge valve, the opening time of which is in a recompression stroke of a stroke-adjustable piston in the at least one cylinder.

6. The piston engine as specified in claim 5, wherein the control device shifts the opening time of the first and second discharge valves, such that both of the first and second discharge valves open synchronously.

7. The piston engine as specified in claim 1, wherein the opening time of both of the first and second discharge valves are at least one of smaller than a 240°

crankshaft angle, smaller than a 200°

crankshaft angle and smaller than a 180°

crankshaft angle.

8. The piston engine as specified in claim 1, wherein all cylinders of the piston engine have the first and second discharge valves that are separately controllable by the shafts of the double overhead camshaft.

9. The piston engine as specified in claim 1, wherein the number of cylinders, both discharge valves of which cylinders being separately controllable by the inner and outer shafts of the double overhead camshaft, is less than the total number of cylinders of the piston engine.

10. The piston engine as specified in claim 1, further comprising:

at least one fast-switching valve that is arranged upstream from the first and second discharge valves and in a line, which conducts fresh gas, of the piston engine;

a control device is provided for controlling the at least one fast-switching valve; and

each cylinder includes at least one of a separate fast-switching valve and a common fast-switching valve.

11. The piston engine as specified in claim 10, wherein the control device of the fast-switching valve is controlled as a function of a current operational state of the piston engine to realize at least one of a pulse charging, a de-throttling, a cold charging and a hot charging.

12. The piston engine as specified in claim 1, wherein a fresh-gas line supplying the cylinders is at least one of unthrottled and de-throttled.

13. The piston engine as specified in claim 1, further comprising:

an injection arrangement for injecting fuel into the cylinder; and

a control device for controlling the injection arrangement,

the control device shifts the injection time to accelerate the turbine.

14. The piston engine as specified in claim 13, wherein the control device in a spark-ignited engine shifts to retard the combustion position of centre of gravity through multiple injections to increase the exhaust-gas enthalpy in comparison with a conventional position of centre of gravity to accelerate the turbine.

15. The piston engine as specified in claim 1, further comprising an ignition device for igniting a fuel-fresh gas mixture in the respective cylinder;

and,

a control device is provided for controlling the ignition device,

the control device shifts the ignition time to accelerate the turbine.

16. The piston engine as specified in claim 2, wherein the opening time of both of the first and second discharge valves are at least one of smaller than a 240°

crankshaft angle, smaller than a 200°

crankshaft angle and smaller than a 180°

crankshaft angle.

17. The piston engine as specified in claim 3, wherein the opening time of both of the first and second discharge valves are at least one of smaller than a 240°

crankshaft angle, smaller than a 200°

crankshaft angle and smaller than a 180°

crankshaft angle.

18. The piston engine as specified in claim 4, wherein the opening time of both of the first and second discharge valves are at least one of smaller than a 240°

crankshaft angle, smaller than a 200°

crankshaft angle and smaller than a 180°

crankshaft angle.

19. The piston engine as specified in claim 5, wherein the opening time of both of the first and second discharge valves are at least one of smaller than a 240°

crankshaft angle, smaller than a 200°

crankshaft angle and smaller than a 180°

crankshaft angle.

20. The piston engine as specified in claim 6, wherein the opening time of both of the first and second discharge valves are at least one of smaller than a 240°

crankshaft angle, smaller than a 200°

crankshaft angle and smaller than a 180°

crankshaft angle.