System and method for safe valve activation in a dynamic skip firing engine

• US 9,650,923 B2
• Filed: 09/18/2015
• Issued: 05/16/2017
• Est. Priority Date: 09/18/2013
• Status: Active Grant

• Current Assignee: Tula Technology, Incorporated
• Original Assignee: Tula Technology, Incorporated
• Inventors: Parsels, John W., Younkins, Matthew A., Chen, Shikui Kevin
• Primary Examiner(s): Amick, Jacob
• Application Number:
  US14/858,046
• Publication Number:
  US 20160024981A1
• Time in Patent Office: 606 Days
• CPC Class Codes: F01L 1/18 Rocking arms or levers
• CPC Class Codes: F01L 13/0005 Deactivating valves
• CPC Class Codes: F01L 2013/001 Deactivating cylinders
• CPC Class Codes: F01L 2820/01 Absolute values
• CPC Class Codes: F01L 2820/033 Hydraulic engines
• CPC Class Codes: F01L 2820/045 Valve lift
• CPC Class Codes: F01L 9/10 by fluid means, e.g. hydraulic
• CPC Class Codes: F01L 9/20 by electric means
• CPC Class Codes: F02D 13/06 Cutting-out cylinders
• CPC Class Codes: F02D 2041/001 for engines with variable valve actuation
• CPC Class Codes: F02D 41/0087 Selective cylinder activation, i.e. partial cylinder operation deceleration cut-off F02D41/123
• CPC Class Codes: F02D 41/1498 measuring engine roughness
• CPC Class Codes: F02D 41/22 Safety or indicating devices for abnormal conditions in air/fuel ratio feedback systems F02D41/1495, in electric control linkage F02D11/107, in purge control systems F02M25/0809
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

A variety of methods and devices for controlling the operation of the intake and exhaust valves in an internal combustion engine during skip fire operation are described. In various embodiments, an exhaust valve monitor or other suitable mechanism is used to detect exhaust valve actuation faults. When an exhaust valve actuation fault is detected for a particular cylinder, the corresponding intake valve is deactivated (or not activated) in circumstances when it would otherwise be activated in order to prevent the intake valve from opening into a cylinder that contains high pressure combustion gases. The described approach is particularly beneficial when skip fire operation is combined with cylinder deactivation so that air is not pumped through the cylinders during the skipped working cycles.

Claims

1. An internal combustion engine comprising:

an engine controller arranged to operate the engine in a skip fire mode;

at least one selectively activatable cylinder, each selectively activatable cylinder having an associated intake valve and an associated exhaust valve, wherein the exhaust valve associated with each selectively activatable cylinder can be selectively opened or held closed during a selected working cycle to help facilitate deactivating the cylinder during skipped working cycles that occur during skip fire operation of the engine such that air is not pumped through the cylinder during the skipped working cycles; and

a valve control system arranged to ensure that during skip fire operation, the intake valve does not open when the selectively activatable cylinder contains high pressure combustion gases, the valve control system including an exhaust valve motion verification module arranged to detect opening of the exhaust valve to vent combustion gases.

2. An engine as recited in claim 1 wherein the valve control system is arranged to activate the intake valve only after the exhaust valve motion verification module has detected the opening of the exhaust valve.

3. An engine as recited in claim 1 wherein the exhaust valve motion verification module uses crankshaft rotation speed or a time based derivative thereof to detect exhaust valve opening.

4. An internal combustion engine comprising:

an engine controller arranged to operate the engine in a skip fire mode;

at least one camshaft arranged to actuate the intake and exhaust valves; and

at least one selectively activatable cylinder, each selectively activatable cylinder having an associated intake valve, an associated exhaust valve, and an associated lost motion device arranged to facilitate selective deactivation of the associated intake and exhaust valves, wherein the exhaust valve associated with each selectively activatable cylinder can be selectively opened or held closed during a selected working cycle to help facilitate deactivating the cylinder during skipped working cycles that occur during skip fire operation of the engine such that air is not pumped through the cylinder during the skipped working cycles; and

a valve control system arranged to ensure that during skip fire operation, the intake valve does not open when the selectively activatable cylinder contains high pressure combustion gases.

5. An engine as recited in claim 4 wherein each lost motion device is a collapsible lifter controlled by hydraulic pressure.

6. An internal combustion engine comprising:

an engine controller arranged to operate the engine in a skip fire mode;

at least one selectively activatable cylinder, each selectively activatable cylinder having an associated intake valve and an associated exhaust valve, wherein the exhaust valve associated with each selectively activatable cylinder can be selectively opened or held closed during a selected working cycle to help facilitate deactivating the cylinder during skipped working cycles that occur during skip fire operation of the engine such that air is not pumped through the cylinder during the skipped working cycles; and

a valve control system arranged to ensure that during skip fire operation, the intake valve does not open when the selectively activatable cylinder contains high pressure combustion gases.

7. An engine as recited in claim 6 wherein the valve control system is arranged to affirmatively activate the intake valve for each desired intake event and to affirmatively deactivate the intake valve after each intake event.

8. An engine as recited in claim 6 wherein an intake valve activation state prior to a selected working cycle may be either active or deactivated based on the intake valve activation state of the immediately prior working cycle for the associated cylinder.

9. An engine as recited in claim 6 wherein the valve control system includes:

an exhaust valve proximity sensor; and

a safety circuit that receives a signal from the exhaust valve proximity sensor, the safety circuit being arranged to detect an exhaust valve actuation failure based at least in part on the signal received from the exhaust valve proximity sensor and to deactivate the intake valve upon the detection of an exhaust valve actuation failure.

10. An engine as recited in claim 6 further comprising an exhaust valve proximity sensor arranged to generate a signal indicative motion of the exhaust valve, wherein the engine controller:

receives the exhaust valve sensor signal; and

directs activation of intake valve only after verifying that the exhaust valve has opened based at least in part of the exhaust valve sensor signal.

11. An engine as recited in claim 6 wherein:

the valve control system includes an intake valve solenoid and an intake valve collapsible lifter, and

opening the intake valve solenoid causes the intake valve collapsible lifter to enter a compressible state whereby the intake valve is deactivated.

12. An engine as recited in claim 6 wherein the valve control system includes:

an intake valve collapsible lifter;

an exhaust valve collapsible lifter; and

a solenoid used to activate and deactivate both the intake valve collapsible lifter and the exhaust valve collapsible lifter.

13. An assembly for controlling the activation and deactivation of a cylinder, the assembly comprising:

an intake valve solenoid;

an exhaust valve solenoid;

a safety circuit arranged to ensure that during skip fire operation, an intake valve controlled by the intake valve solenoid does not open when the cylinder contains high pressure combustion gases;

an electrical receptacle; and

a mechanical member,

wherein the intake valve solenoid, the exhaust valve solenoid, the safety circuit, and the electrical receptacle are all mounted on the mechanical member.

14. An assembly as recited in claim 13 wherein the mechanical member is a lead frame.

15. An assembly as recited in claim 13 wherein the mechanical member is a circuit board.

16. An assembly a recited in claim 13 wherein the assembly includes a plurality of intake valve solenoids and a plurality of exhaust valve solenoids, wherein each intake valve solenoid is arranged to control activation of an associated intake valve and each exhaust valve solenoid is arranged to control activation of an associated exhaust valve.

17. An assembly for controlling the activation and deactivation of a cylinder, the assembly comprising:

at least one valve activation solenoid;

a safety circuit arranged to ensure that during skip fire operation, an intake valve controlled by the at least one valve activation solenoid does not open when the cylinder contains high pressure combustion gases;

an electrical receptacle; and

a mechanical member, and

wherein the at least one valve actuation solenoid, the safety circuit, and the electrical receptacle are all mounted on the mechanical member.

18. A package as recited in claim 17 wherein the mechanical member is a lead frame.

19. A package as recited in claim 17 wherein the mechanical member is a circuit board.

20. A package as recited in claim 17 wherein:

the at least one valve actuation solenoid includes an intake valve solenoid arranged to activate a corresponding intake valve and an exhaust valve solenoid arranged to activate a corresponding exhaust valve; and

the intake valve solenoid and the exhaust valve solenoid are both mounted on the mechanical member.

21. An package a recited in claim 17 wherein the at least one valve actuation solenoid includes a plurality of intake valve solenoids and a plurality of exhaust valve solenoids, wherein each intake valve solenoid is arranged to control activation of an associated intake valve and each exhaust valve solenoid is arranged to control activation of an associated exhaust valve.

22. A package as recited in claim 17 wherein a single valve actuation solenoid is provided and the valve actuation solenoid is arranged to activate both a corresponding intake valve and a corresponding exhaust valve.

23. An assembly as recited in claim 17 wherein a single valve actuation solenoid is provided and the valve actuation solenoid is arranged to activate both a corresponding intake valve and a corresponding exhaust valve.