Internal combustion engine and a method comprising control of the engine to provide a braking torque

Patent metadata

Field	Value
Publication number	US-10801419-B2
Application number	US-201616061348-A
Country	US
Kind code	B2
Filing date	Jan 29, 2016
Priority date	Jan 29, 2016
Publication date	Oct 13, 2020
Grant date	Oct 13, 2020

Abstract

An internal combustion engine is provided including a cylinder including a piston connected to a rotatable crankshaft, an exhaust guide being arranged to guide a gas flow from the cylinder, an adjustable flow restriction element arranged to restrict the flow through the exhaust guide, an exhaust valve arranged to control a communication between the cylinder and the exhaust guide, and an exhaust valve actuation assembly for actuating the exhaust valve so as to perform in each of a plurality of cycles of the cylinder an exhaust valve actuation sequence, wherein the exhaust valve actuation assembly is adapted to control the commencement of the exhaust valve actuation sequence to occur selectively at any crankshaft angle within a non-zero crankshaft angle interval.

First claim

The invention claimed is:

1. An internal combustion engine comprising:
a cylinder comprising a piston connected to a rotatable crankshaft,
an exhaust guide being arranged to guide a gas flow from the cylinder,
an adjustable flow restriction element arranged to restrict the flow through the exhaust guide,
an exhaust valve arranged to control a communication between the cylinder and the exhaust guide, and
an exhaust valve actuation assembly for actuating the exhaust valve so as to perform in each of a plurality of cycles of the cylinder an exhaust valve actuation sequence,
wherein the exhaust valve actuation assembly is adapted to control, during engine braking, a commencement of the exhaust valve actuation sequence to occur selectively at any crankshaft angle within a non-zero crankshaft angle interval, wherein the exhaust actuation sequence is moveable within the non-zero crankshaft angle interval.

2. An engine according to claim 1 , wherein the exhaust valve actuation assembly comprises a rotatable camshaft arrangement, the camshaft arrangement being adapted to provide the control of the commencement of the exhaust valve actuation sequence to occur selectively at any crankshaft angle within the non-zero crankshaft angle interval.

3. An engine according to claim 1 , wherein the exhaust valve actuation assembly includes a rotatable camshaft, wherein the exhaust valve actuation assembly is controllable for adjusting the phase of the camshaft rotation in relation of the crankshaft rotation.

4. An engine according to claim 3 , wherein the exhaust valve actuation assembly comprises a variator for variable valve timing.

5. An engine according to claim 1 , wherein the exhaust valve actuation sequence is a decompression opening sequence of the exhaust valve commenced in a compression stroke of the respective cycle of the cylinder, the exhaust valve actuation assembly being controllable for selectively providing the decompression opening sequence.

6. An engine according to claim 5 , wherein the exhaust valve actuation assembly comprises, a camshaft presenting at least one cam lobe presenting a decompression nose for the decompression opening sequence, the exhaust valve actuation assembly being controllable for selectively actuating the exhaust valve by means of the decompression nose.

7. An engine according to claim 1 , wherein the exhaust valve actuation sequence is a charging opening sequence of the exhaust valve commenced in a second half of an intake stroke or a first half of a compression stroke of the cylinder, the exhaust valve actuation assembly being controllable for selectively providing the charging opening sequence.

8. An engine according to claim 7 , wherein the exhaust valve actuation assembly comprises a camshaft presenting at least one cam lobe presenting a charging nose for the charging opening sequence, the exhaust valve actuation assembly being controllable for selectively actuating the exhaust valve by means of the charging nose.

9. An engine according to claim 1 , wherein the flow restriction element is arranged to provide a plurality of levels of the flow restriction depending on the adjustment of the flow restriction element.

10. An engine according to claim 1 , wherein the flow restriction element is adapted to provide the restriction of the flow restriction element at any level within a non-zero restriction interval.

11. An engine according to claim 1 , wherein the flow restriction element comprises a throttle valve in the exhaust guide.

12. An engine according to claim 1 , wherein the engine comprises a turbocharger comprising a turbine, the exhaust guide being arranged to guide the gas flow from the cylinder to the turbine, wherein the adjustable flow restriction element is arranged between the cylinder and the turbine.

13. An engine according to claim 12 , wherein the cylinder, the exhaust guide and the flow restriction element are a first cylinder, a first exhaust guide and a first flow restriction element, the engine further comprising a second cylinder, a second exhaust guide being arranged to guide a gas flow from the second cylinder to the turbine, and a second adjustable flow restriction element arranged upstream of the turbine to restrict the flow from the second cylinder to the turbine, wherein the flow from the second cylinder to the turbine is kept separate from the flow from the first cylinder to the turbine.

14. An engine according to claim 1 , wherein the engine comprises a variable geometry turbocharger comprising a turbine, the exhaust guide being arranged to guide the gas flow from the cylinder to the turbine, wherein the turbocharger is arranged to provide at the turbine an adjustable restriction of the gas flow in addition to the restriction which the adjustable flow restriction element is arranged to provide.

15. An engine according to claim 1 , wherein the engine comprises a variable geometry turbocharger comprising a turbine, the exhaust guide being arranged to guide the gas flow from the cylinder to the turbine, wherein the adjustable flow restriction element is provided by a flow adjusting function at the turbine.

16. A vehicle with an engine according to claim 1 .

17. A method of controlling an internal combustion engine in a vehicle comprising a cylinder, a fuel system for supplying fuel to the cylinder, an exhaust guide arranged to guide a gas flow from the cylinder, an exhaust valve arranged to control a communication between the cylinder and the exhaust guide, the method comprising:
controlling the engine to provide a braking torque, the control comprising,
terminating the supply of fuel to the cylinder, restricting the flow through the exhaust guide,
performing in each of a plurality of cycles of the cylinder an exhaust valve actuation sequence, wherein the exhaust valve actuation sequence comprises
a main opening sequence of the exhaust valve with a maximum degree of opening of the exhaust valve in an exhaust stroke of the cylinder,

wherein the control of the engine to provide a braking torque also comprises
determining a value of an engine parameter affecting the pressure in the cylinder and/or the air mass flow through the cylinder, and
in dependence on the determined engine parameter value adjusting the timing, during engine braking, of a commencement of the exhaust valve actuation sequence, to occur selectively at any crankshaft angle within a non-zero crankshaft angle interval, wherein the exhaust actuation sequence is moveable within the non-zero crankshaft angle interval.

18. A method according to claim 17 , wherein adjusting the timing of the commencement of the exhaust valve actuation sequence comprises adjusting the crankshaft angle at which the exhaust valve actuation sequence is commenced.

19. A method according to claim 18 , wherein the cylinder comprises a piston connected to a rotatable crankshaft and an exhaust valve actuation assembly includes a rotatable camshaft, wherein the timing of the commencement of the exhaust valve actuation sequence is adjusted by adjusting the phase of the camshaft rotation in relation of the crankshaft rotation.

20. A method according to claim 17 , wherein the engine parameter is the engine rotational speed, the engine torque, a pressure in an air guide arranged to guide an air flow from a compressor of a turbocharger of the engine to the cylinder, a rotational speed of the turbocharger, or a pressure in the exhaust guide.

21. A method according to claim 17 , comprising determining a value of a furth

Assignees

• Volvo Truck Corp

Inventors

• Mohlin Anders

Classifications

• F02D9/06

  Exhaust brakes · CPC title

• F01L13/065

  Compression release engine retarders of the "Jacobs Manufacturing" type · CPC title

• Y02T10/12

  Improving ICE efficiencies · CPC title

• F02D9/101

  Special flap shapes, ribs, bores or the like · CPC title

• F02D2200/101

  Engine speed · CPC title