Variable displacement pump and control therefor

• US 20030231965A1
• Filed: 04/03/2003
• Published: 12/18/2003
• Est. Priority Date: 04/03/2002
• Status: Active Grant

• Current Assignee: SLW Automotive, Inc.
• Original Assignee: Renesas Technology Corporation (Renesas Electronics Corporation)
• Inventors: Koenig, Dennis, Hunter, Douglas
• Granted Patent: US 7,018,178 B2
• Time in Patent Office: Days
• US Class Current: 417/212
• CPC Class Codes: F01M 1/16 Controlling lubricant pressure or quantity rendering machines or engines inoperative or idling on lubricant pressure failure F01M1/22
• CPC Class Codes: F04C 14/22 by changing the eccentricity between cooperating members
• CPC Class Codes: F04C 2270/01 Load
• CPC Class Codes: F04C 2270/052 angular
• CPC Class Codes: F04C 2270/18 Pressure

Abstract

A control system for a variable displacement pump. The control system is operably associated with an engine control unit for passively or actively controlling the output of the pump in response to signals from the engine control unit.

Claims

1. A control system for controlling a variable displacement pump for controlling oil flow and oil pressure in a circuit in an engine comprising:

a pump;

an actuating member capable of controlling the displacement of said pump;

a solenoid being operably associated with said actuating member for selectively controlling the displacement of said pump; and

an electronic control unit connected to and providing an input control signal to said solenoid for controlling oil flow and oil pressure.

2. The control system of claim 1 wherein the actuating member is hydraulically actuated and said solenoid is used to control oil flow and oil pressure from said pump.

3. The control system of claim 1 wherein the solenoid directly engages the actuating member for controlling the displacement of said pump.

4. The control system of claim 3 wherein said electronic control unit is connected to and monitors the pressure in a pilot line that is connected to an engine fluid pressure circuit, wherein said electronic control unit generates input signals to said solenoid in response to pressure conditions in said pilot line for controlling displacement of said pump.

5. The control system of claim 2 further comprising a flow control spool valve which is controlled by said solenoid to control actuation flow to said actuating member.

6. The control system of claim 5 wherein said electronic control unit is connected to and monitors the pressure in a pilot line that is connected to an engine oil pressure circuit, wherein said electronic control unit generates input signals to said solenoid in response to pressure conditions in said pilot line for controlling displacement of said pump.

7. The control system of claim 5 wherein said flow control spool valve is connected to on-stroke and destroke actuators on said pump, wherein oil from said flow control spool valve is inputted to one of either said on-stroke and said destroke actuators for setting displacement of said pump during operation.

8. The control system of claim 5 wherein said flow control valve is a spool valve and said solenoid is directly connected to said spool valve.

9. The control system of claim 8 wherein said electronic control unit is connected to and monitors the pressure in a pilot line that is connected to an engine oil pressure circuit, wherein said electronic control unit generates input signals to said solenoid in response to pressure conditions in said pilot line for controlling displacement of said pump.

10. The control system of claim 9 wherein the ECU monitors the oil pressure and actively adjusts the system on a real time basis to control oil pressure in said engine oil pressure circuit.

11. The control system of claim 8 further comprising a variable target piston and a piston spring connected to said spool valve, wherein said valve member adjusts the position of said variable target piston and piston spring to set the target pressure discharged from said pump.

12. The control system of claim 5 further comprising:

a valve member functionally connected between said solenoid and said spool valve, wherein said spool valve controls the amount of hydraulic pressure inputted to said actuating member in response to the movement of said solenoid.

13. The control system of claim 12 wherein said solenoid is directly connected to said valve member and controls the opening and closing of said valve member.

14. The control system of claim 13 wherein said electronic control unit is connected to and monitors the pressure in a pilot line that is connected to an engine oil pressure circuit, wherein said electronic control unit generates input signals to said solenoid in response to pressure conditions in said pilot line for controlling displacement of said pump.

15. The control system of claim 13 further comprising a variable target piston and a piston spring connected to said spool valve, wherein said valve member changes the pressure exerted on said variable target piston and piston spring to set the target pressure discharged from said pump.

16. The control system of claim 15 wherein said valve member is connected to a sump, so that when said solenoid closes said valve member, said input pressure to said actuating member increases.

17. The control system of claim 16 wherein said ECU monitors engine conditions and provides a current indicative of the target pressure to said valve member, and wherein said pump is self-regulated to the target pressure by mechanical and hydraulic controls.

18. The control system of claim 17 wherein said engine conditions monitored comprise engine temperature, engine speed, engine load and combinations thereof.

19. The control system of claim 18 further comprising a pressure reducing and regulating valve configured between said valve member and a discharge port from said pump, wherein said pressure reducing and regulating valve creates a fixed input pressure to said valve member.

20. The control system of claim 15 wherein said input pressure to said actuating member decreases when said solenoid closes said valve member.

21. The control system of claim 19 wherein said ECU monitors engine conditions and provides a target pressure to said variable target piston and said spool valve, wherein said pump is self-regulated to the target pressure by mechanical and hydraulic controls.

22. The control system of claim 20 wherein said engine conditions monitored comprise engine temperature, engine speed, engine load and combinations thereof.

23. The control system of claim 21 further comprising a pressure reducing and regulating valve configured between said valve member and a pilot pressure port from said pump, wherein said pressure reducing and regulating valve creates a fixed input pressure to said valve member.

24. The control system of claim 7 wherein the spool is biased in a first direction with a return spring and said solenoid biases said valve against said return spring by directly engaging said flow control valve.

25. The control system of claim 24 wherein said spool valve is hydraulically actuated and said solenoid controls a valve for moving oil from a discharge of said pump to said spool valve for controlling said spool valve.

26. A variable displacement pump for an engine having an engine control unit comprising:

a pump having an actuator that controls the pressure and flow of oil to a pressure lubricating circuit of an engine;

a pilot pressure line that has oil flow and oil pressure supplied by the engine;

a flow control valve for hydraulically varying the pump displacement by facilitating movement of said actuator; and

a solenoid controlled by said engine control unit, said solenoid being operably associated with said flow control valve for providing control of oil flow through said flow control valve.

27. The variable displacement pump of claim 26, wherein said engine control unit monitors engine conditions and parameters and varies the amount of current to said solenoid in response to said conditions and said parameters.

28. The variable displacement pump of claim 26 wherein said pump is a vane pump and said actuator is at least part of an eccentric ring of said vane pump, wherein said vane pump and said eccentric ring operate to control the displacement of fluid to said engine.

29. The variable displacement pump of claim 28 further comprising a pressure reducing and regulating valve located between said discharge port and said solenoid valve, wherein said pressure reducing and regulating valve functions to provide a constant pressure to said solenoid valve.

30. The variable displacement pump of claim 26 wherein said solenoid is a variable force solenoid.

31. The variable displacement pump of claim 30 further comprising a compression spring connectable at a first end to said flow control valve, wherein said compression spring maintains pressure on said fluid control valve during regular operation, and provides return pressure in the absence of pilot pressure on said fluid control valve.

32. The variable displacement pump of claim 31 further comprising a target piston connected to the second end of said compression spring, wherein said target piston exerts force on said compression spring.

33. The variable displacement pump of claim 32 wherein said solenoid is connected to said target piston so as to directly control the movement of said target piston, wherein said solenoid further comprises an engine control unit operably connected to said solenoid, wherein said engine control unit monitors engine conditions and parameters and varies the value of an input signal and adjusts said solenoid in response to said conditions and parameters.

34. The variable displacement pump of claim 32 wherein said solenoid is connected directly to said flow control valve and regulates the stroke and de-stroke conditions of said flow control valve, wherein said method further comprises an engine control unit operably connected to and sending a control signal to said solenoid, wherein said engine control unit is connected to and monitors the oil flow and oil pressure of said pilot line and generates said input signal in response to the pressure conditions of said pilot line.

35. The variable displacement pump of claim 32 further comprising a valve operably associated with said solenoid, wherein said valve is connectable between said discharge port of said engine and said target piston, wherein said valve controls the amount of pressure exerted on said target piston and said compression spring.

36. The variable displacement pump of claim 35 further comprising an engine control unit connected to said solenoid, wherein said engine control unit monitors engine conditions and parameters and varies the value of an input to said solenoid in response to said conditions and said parameters.

37. The variable displacement pump of claim 36 wherein said pump is a vane pump and said actuator is an eccentric ring of said vane pump, wherein said vane pump and said eccentric ring operate to control the displacement of fluid to said engine.

38. A variable displacement pump for an engine comprising:

a vane pump having an eccentric ring that controls the flow of fluid to an engine input;

a pilot pressure line that has oil flow and oil pressure supplied indicative of a controlled oil flow and oil pressure in the engine;

a flow control valve for mechanically varying the pump displacement by facilitating movement of said eccentric ring;

a compression spring connectable at a first end to said flow control valve, wherein said compression spring maintains pressure on said flow control valve during regular operation, and provides return pressure in the absence of pilot pressure on said flow control valve;

a target piston connected to the second end of said compression spring, wherein said target piston exerts force on said compression spring;

a valve connectable between a discharge port of the pump and said target piston, wherein said valve controls the amount of pressure exerted on said target piston and said compression spring;

a solenoid connected to and controlling said valve for providing pressure control of fluid flow through said valve; and

an engine control unit connected to said solenoid, wherein said engine control unit monitors engine conditions and parameters and varies the amount of current to said solenoid for controlling the pressure exerted or said target pistons in response to said conditions and said parameters sensed by the ECU.