Internal combustion engine having an oil circuit and method for operating such an internal combustion engine

Patent metadata

Field	Value
Publication number	US-9243526-B2
Application number	US-201213457971-A
Country	US
Kind code	B2
Filing date	Apr 27, 2012
Priority date	May 20, 2011
Publication date	Jan 26, 2016
Grant date	Jan 26, 2016

Abstract

A method for operating an engine is provided. The method comprises adjusting an oil pressure in an oil circuit, the oil circuit including a pump in fluidic communication with a hydraulically adjustable cam follower and switching the hydraulically adjustable cam follower into a connected state to a disconnected in response to the oil pressure adjustment.

First claim

The invention claimed is:

1. An internal combustion engine comprising:
a cylinder including an intake port and an exhaust port;
a valve train comprising a deactivatable intake valve positioned in the intake port, a deactivatable exhaust valve positioned in the exhaust port, an intake valve actuating assembly comprising an intake camshaft having an intake cam and a hydraulically adjustable intake cam follower positioned between the intake valve and the intake cam, and an exhaust valve actuating assembly comprising an exhaust camshaft having an exhaust cam and a hydraulically adjustable exhaust cam follower positioned between the exhaust cam and the exhaust valve; and
an oil circuit including a variable pump and an electrically controllable pump valve coupled to an inlet of the variable pump, the variable pump providing an output of pressurized oil to a supply line of the oil circuit, a pressure of the oil output by the pump to the supply line being adjustable via the electrically controllable pump valve, the intake cam follower and exhaust cam follower in fluidic communication with an outlet of the variable pump via the supply line,
wherein the intake cam follower is connected with the deactivatable intake valve and the exhaust cam follower is connected with the deactivatable exhaust valve when the pressure of the oil in the supply line exceeds a predetermined threshold, and
wherein the intake cam follower is disconnected from the deactivatable intake valve and the exhaust cam follower is disconnected from the deactivatable exhaust valve when the pressure of oil in the supply line is below the predetermined threshold.

2. The internal combustion engine of claim 1 , wherein when the intake cam follower is connected with the intake valve, it is in a connected state receiving rotation energy from the intake cam and transferring the energy to the intake valve to perform an oscillatory lifting movement, wherein when the intake cam follower is disconnected from the intake valve, it is in a disconnected state inhibiting the transfer of energy from the intake cam to the intake valve, wherein when the exhaust cam follower is connected with the exhaust valve, it is in a connected state receiving rotation energy from the exhaust cam and transferring the energy to the exhaust valve to perform an oscillatory lifting movement, and wherein when the exhaust cam follower is disconnected from the exhaust valve, it is in a disconnected state inhibiting the transfer of energy from the exhaust cam to the exhaust valve.

3. The internal combustion engine of claim 1 , where the cylinder further comprises a second intake port and a second exhaust port.

4. The internal combustion engine of claim 1 , where the intake port is in fluidic communication with an intake manifold and the exhaust port is in fluidic communication with an exhaust manifold.

5. The internal combustion engine of claim 1 , where the intake and exhaust cam followers are hydraulically adjustable tappets.

6. The internal combustion engine of claim 5 , where the hydraulically adjustable tappets each comprise two separate but inter-connectible components, which are connected together when the tappet is in a connected state, and moveable relative to one another when it is in a disconnected state.

7. The internal combustion engine of claim 1 , where the variable pump is a vane pump, the eccentricity of which is adjustable.

8. The internal combustion engine of claim 7 , where the eccentricity of the vane pump is adjustable via the electrically controllable pump valve, the electrically controllable pump valve in electronic communication with an engine control.

9. The internal combustion engine of claim 1 , further comprising at least one of a filter and an oil cooler positioned in the supply line downstream of the variable pump.

10. The internal combustion engine of claim 9 , where the filter and the oil cooler are arranged upstream of a valve train.

11. The internal combustion engine of claim 1 , further comprising a cylinder head connected to a cylinder block, the cylinder block at least partially enclosing a crankshaft and two main bearings coupled to the crankshaft, where the supply line opens into a main oil gallery in fluidic communication with the two main bearings.

12. The internal combustion engine of claim 11 , where the cylinder block includes an upper portion of a crankcase and is connected to an oil sump, the oil sump spaced away from the cylinder head and collecting and storing engine oil, the oil sump including a lower portion of the crankcase, the oil circuit further comprising a suction line positioned in the oil sump and in fluidic communication with the pump.

13. The internal combustion engine of claim 1 , where the pump is a displacement pump.

14. A method for operating an engine comprising:
adjusting an oil pressure at an outlet of a variable pump in an oil circuit through adjustment of an electrically controllable pump valve coupled to an inlet pressure line of the variable pump, the oil circuit including a hydraulically adjustable cam follower in fluidic communication with the outlet of the variable pump via a supply line, wherein the hydraulically adjustable cam follower is in a connected state when an oil pressure at the outlet of the variable pump exceeds a predetermined threshold and wherein the hydraulically adjustable cam follower is in a disconnected state when the oil pressure at the outlet of the variable pump is below the predetermined threshold.

15. The method of claim 14 , where adjusting the oil pressure includes increasing the oil pressure.

16. The method of claim 15 , where the oil pressure in the oil circuit is increased in response to an increase in at least one of engine load and engine speed.

17. The method of claim 14 , where adjusting the oil pressure includes decreasing the oil pressure.

18. The method of claim 14 , where the oil pressure in the oil circuit is increased by increasing an output of the pump.

19. A method for operating an engine comprising:
switching a hydraulically adjustable cam follower into a connected state by adjusting an electrically controllable pump valve coupled to an inlet pressure line of a variable pump in an oil circuit to increase an oil pressure in the oil circuit at an outlet of the variable pump above a predetermined threshold value, the hydraulically adjustable cam follower in fluidic communication with the outlet of the variable pump; and
switching the hydraulically adjustable cam follower into a disconnected state by adjusting the electrically controllable pump valve to decrease the oil pressure in the oil circuit below the predetermined threshold value.

20. The internal combustion engine of claim 1 , wherein the supply line opens into a main oil gallery of the oil circuit, wherein the inlet of the variable pump is a first inlet, wherein the variable pump further comprises a second inlet, and wherein the oil circuit further comprises a first pressure line, the first pressure line coupling the main oil gallery with either the first inlet or an oil sump depending on a state of the electrically controllable pump valve, and a second, permanently open pressure line coupling the main oil gallery to the second inlet of the variable pump.

Assignees

• Mehring Jan
• Grieser Klemens
• Kuhlbach Kai Sebastian
• Steiner Bernd
• Ford Global Tech Llc

Inventors

• Mehring Jan
• Grieser Klemens
• Kuhlbach Kai Sebastian
• Steiner Bernd

Classifications

• F01M2001/0238

  Rotary pumps · CPC title

• F01L13/0005

  Deactivating valves · CPC title

• F01M1/16 Primary

  Controlling lubricant pressure or quantity (rendering machines or engines inoperative or idling on lubricant pressure failure F01M1/22) · CPC title