Partial deactivation of an internal combustion engine

Patent metadata

Field	Value
Publication number	US-2016195031-A1
Application number	US-201514964257-A
Country	US
Kind code	A1
Filing date	Dec 9, 2015
Priority date	Jan 6, 2015
Publication date	Jul 7, 2016
Grant date	—

Abstract

Methods and systems are provided for an internal combustion engine having at least two cylinders configured in such a way that they form two groups, at least one cylinder of a first group being a cylinder which is operational in the event of a partial deactivation of the engine, and at least one cylinder of a second group being formed as a load-dependently switchable cylinder. An inlet-side throttle element is provided with at least one intake line of the switchable cylinder, by means of which the size of the flow cross section of the intake line can be varied, whereby the charge-air flow rate supplied to the deactivated cylinder in the event of a partial deactivation of the engine can be adjusted. Each outlet opening of a load-dependently switchable cylinder is equipped with a partially variable valve drive, with an outlet valve which opens or shuts off the outlet opening.

First claim

1 . An internal combustion engine system comprising:
at least a first and a second cylinder group, each of the first and second cylinder group comprising at least one cylinder, wherein each engine cylinder includes an outlet coupled to an exhaust line for discharging exhaust gases to an exhaust system and an inlet coupled to an intake line for receiving charge air from an intake system, wherein the at least one cylinder of the first cylinder group remains active when engine is partially shut down as a function of engine load, and wherein the at least one cylinder of the second group is deactivated when the engine is partially shutdown; at least one throttle element coupled to the intake line of the at least one cylinder of the second cylinder group to vary a size of a flow cross section of the intake line; and a variable valve drive coupled to an exhaust valve of the at least one cylinder of the second cylinder group, wherein actuation of the variable valve drive deactivates the exhaust valve when the engine is partially shutdown while an intake valve of the at least one cylinder of the second cylinder group remains active.

2 . The system of claim 1 , wherein actuation of the variable valve drive oscillates the exhaust valve to realize a valve lift Δh between an open position and a closed position of the exhaust valve, and to open up the outlet of the at least one cylinder of the second cylinder group for an opening duration Δt, and wherein the intake valve of the at least one cylinder of the second cylinder group is coupled to a fixed valve drive.

3 . The system of claim 1 , wherein the at least one throttle element is one of a valve and a pivotable flap, and wherein the position of the at least one throttle element is continuously adjustable between a fully open and a fully closed position.

4 . The system of claim 1 , further comprising at least one exhaust-gas turbocharger including a turbine arranged in the exhaust line and a compressor arranged in the intake line.

5 . The system of claim 1 , wherein the engine includes four cylinders in an in-line arrangement, and wherein the first group of cylinders includes two outer cylinders and wherein the second group of cylinders includes two inner cylinders in the in-line arrangement.

6 . The system of claim 1 , wherein the at least one throttle element is coupled to the intake line of the at least one cylinder of the second cylinder group upstream of a location where the intake line branches from an overall intake line in an engine inlet manifold.

7 . The system of claim 1 , wherein the at least one throttle element includes a plurality of throttle elements, each of the plurality of throttle elements coupled to an intake line of a corresponding cylinder of the second cylinder group.

8 . The system of claim 1 , further comprising at least another throttle element coupled to the intake line of the at least one cylinder of the first cylinder group to vary a size of a flow cross section of the intake line.

9 . The system of claim 1 , further comprising a controller with computer-readable instructions stored on non-transitory memory for:
during the partial shutdown of the engine, deactivating fueling of the second group of cylinders, then closing the throttle element, and then actuating the variable valve drive to deactivate the exhaust valve.

10 . The system of claim 2 , wherein the variable valve drive varies a lift of the exhaust valve is one of a continuously adjustable and a stepped fashion.

11 . A method, comprising:
in response to a decrease in engine load below a threshold,
selectively deactivating fueling of a second group of cylinders while maintaining a first group of cylinders active;
then, deactivating exhaust valves of the second group of cylinders after completing an exhaust stroke while maintaining intake valves of the second group of cylinders active; and;
after deactivating the exhaust valves, closing a throttle element in an intake line of the second group of cylinders; and
during cylinder reactivation,
fully opening the throttle element before reactivating the exhaust valves and resuming fueling of the second group of cylinders.

12 . The method of claim 11 , wherein selective deactivating the exhaust valves while maintaining intake valves active includes selectively deactivating a variable valve mechanism coupled to the exhaust valves of the second group of cylinders, the variable valve mechanism not coupled to the intake valves of the second group of cylinders.

13 . The method of claim 11 , further comprising in response to a drop in engine temperature, actuating the variable valve mechanism to admit warm exhaust gas from an exhaust line into the second group of cylinders.

14 . The method of claim 11 , wherein the engine is a boosted engine including an intake compressor, the method further comprising, in response to a pressure ratio exceeding a surge level, fully opening the throttle element while actuating the variable valve mechanism to decrease the pressure ratio below the surge level.

15 . The method of claim 11 , wherein closing the throttle element includes adjusting a degree of closure of the throttle element based on engine operating conditions, the degree of closure increased as engine load increases while the second cylinder group is deactivated.

16 . The method of claim 11 , wherein the second group of cylinders includes a plurality of cylinders, each of the plurality of cylinders coupled to an intake line, and wherein the throttle element is coupled to the intake line of each of the plurality of cylinders in the second group of cylinders.

17 . A method for an engine, comprising:
in response to cylinder deactivation conditions being met, deactivating fuel to a second group of cylinders while maintaining fueling of a first group of cylinders; closing a throttle element coupled to an intake line of the second group of cylinders; actuating a variable valve mechanism to deactivate exhaust valves of the second group of cylinders while maintaining intake valves active.

18 . The method of claim 17 , wherein after the throttle element is closed after deactivating the fuel, and wherein the exhaust valves are deactivated before an exhaust stroke following the throttle element closing.

19 . The method of claim 17 , wherein the exhaust valves are deactivated after an exhaust stroke following the fuel deactivation, and the throttle element is closed after the exhaust valves are deactivated.

20 . The method of claim 17 , wherein in response to cylinder reactivation conditions being met,
selectively reactivating fuel to the second group of cylinders while actuating the variable valve mechanism to reactivate the exhaust valves of the second group of cylinders; and then opening the throttle element.

Assignees

• Ford Global Tech Llc

Inventors

• Willems Werner
• Turner Paul Nigel
• Stief Juergen Karl
• Chen Guohui

Classifications

• Y02T10/12

  Improving ICE efficiencies · CPC title

• F02D41/0082

  per groups or banks (F02D41/0087 takes precedence) · CPC title

• F02D41/0087 Primary

  Selective cylinder activation, i.e. partial cylinder operation (deceleration cut-off F02D41/123) · CPC title

• F02D9/02

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

• F02D13/0249

  changing the valve timing only · CPC title