Internal combustion engine and a method for controlling a braking torque of the engine

Patent metadata

Field	Value
Publication number	US-10859007-B2
Application number	US-201616333249-A
Country	US
Kind code	B2
Filing date	Oct 6, 2016
Priority date	Oct 6, 2016
Publication date	Dec 8, 2020
Grant date	Dec 8, 2020

Abstract

An internal combustion engine includes a cylinder including a piston connected to a rotatable crankshaft, an air guide arranged to guide an air flow to the cylinder an adjustable air flow restriction element arranged to restrict the How through the air guide, an exhaust guide being arranged to guide a gas flow from the cylinder, an adjustable exhaust 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. A method of controlling an internal combustion engine ( 1 ) in a vehicle comprising a cylinder, a fuel system for supplying fuel to the cylinder, an air guide arranged to guide an air flow 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,
restricting the flow through the air guide,
performing in each of a plurality of cycles of the cylinder an exhaust valve actuation sequence,
determining a value of at least one engine parameter affecting the pressure in the cylinder and/or the air mass flow through the cylinder, and

in dependence on at least one of the at least one determined engine parameter value adjusting the restriction of the flow through the air guide,
wherein the control of the engine to provide a braking torque also comprises in dependence on at least one of the at least one determined engine parameter value adjusting the timing of a commencement of the exhaust valve actuation sequence to occur selectively at any crankshaft angle within a non-zero crankshaft angle interval.

2. A method according to claim 1 , wherein each of the at least one the engine parameter is one of the engine rotational speed, a requested engine braking torque, a current engine braking torque, a pressure in the air guide, a rotational speed of a turbocharger of the engine, and a pressure in the exhaust guide.

3. A method according to claim 1 , wherein adjusting the restriction of the flow through the air guide comprises adjusting a throttle valve in the air guide.

4. A method according to claim 1 , wherein the adjustment of the restriction of the flow through the air guide is a closed loop adjustment.

5. A method according to claim 4 , wherein a pressure in the air guide is a feedback parameter in the closed loop adjustment.

6. A method according to claim 4 , wherein a pressure in the exhaust guide is a feedback parameter in the closed loop adjustment.

7. A method according to claim 1 , 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.

8. A method according to claim 1 , wherein the adjustment of the timing of the commencement of the exhaust valve actuation sequence is an open loop adjustment.

9. A method according to claim 1 , wherein the exhaust valve actuation sequence comprises a decompression opening sequence commenced in a compression stroke of the cylinder.

10. A method according to claim 1 , wherein the exhaust valve actuation sequence comprises 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.

11. A method according to claim 1 , comprising in dependence on at least one of the at least one determined engine parameter value adjusting the restriction of the flow through the exhaust guide.

12. A method according to claim 11 , wherein the adjustment of the restriction of the flow through the exhaust guide is an open loop adjustment.

13. A method according to claim 1 , wherein restricting the flow through the exhaust guide comprises adjusting a throttle valve in the exhaust guide, and/or adjusting a flow adjustment function at a turbine of a variable geometry turbocharger of the engine, wherein the exhaust guide is arranged to guide the gas flow from the cylinder to the turbine.

14. A computer comprising a computer program for causing an internal combustion engine to perform the steps of claim 1 when the program is run on the computer.

15. A non-transitory computer readable medium carrying a computer program for causing an internal combustion engine to perform the steps of claim 1 when the program product is run on a computer.

16. A control unit configured to perform the steps of the method according to claim 1 .

Assignees

• Volvo Truck Corp

Inventors

• Mohlin Anders

Classifications

• F02D9/02

  concerning induction conduits (throttle valves, or arrangements thereof in conduits F02D9/08) · CPC title

• Y02T10/12

  Improving ICE efficiencies · CPC title

• F02D9/06

  Exhaust brakes · CPC title

• F02D2009/0242

  Increasing exhaust brake effect · CPC title

• F01L1/34

  characterised by the provision of means for changing the timing of the valves without changing the duration of opening {and without affecting the magnitude of the valve lift} · CPC title