FUEL PUMP PRESSURE CONTROL STRUCTURE AND METHODOLOGY

• US 20190331053A1
• Filed: 10/24/2017
• Published: 10/31/2019
• Est. Priority Date: 10/24/2016
• Status: Active Grant

• Current Assignee: Cummins Incorporated
• Original Assignee: Cummins Incorporated
• Inventors: Benson, Donald J., Peavler, Paul
• Granted Patent: US 10,968,857 B2
• Time in Patent Office: Days
• CPC Class Codes: F02D 2200/0602 Fuel pressure
• CPC Class Codes: F02D 2250/04 Fuel pressure pulsation in common rails
• CPC Class Codes: F02D 2250/31 Control of the fuel pressure
• CPC Class Codes: F02D 41/008 Controlling each cylinder individually
• CPC Class Codes: F02D 41/1497 With detection of the mechanical response of the engine
• CPC Class Codes: F02D 41/38 of the high pressure type
• CPC Class Codes: F02D 41/3845 by controlling the flow into the common rail, e.g. the amount of fuel pumped
• CPC Class Codes: F02M 2200/247 Pressure sensors
• CPC Class Codes: F02M 59/02 of reciprocating-piston or reciprocating-cylinder type
• CPC Class Codes: F02M 59/08 characterised by two or more pumping elements with conjoint outlet or several pumping elements feeding one engine cylinder feeding common rails F02M63/0225
• CPC Class Codes: F02M 63/02 Fuel-injection apparatus having several injectors fed by a common pumping element, or having several pumping elements feeding a common injector; Fuel-injection apparatus having provisions for cutting-out pumps, pumping elements, or injectors; Fuel-injection apparatus having provisions for variably interconnecting pumping elements and injectors alternatively
• CPC Class Codes: F02M 63/0225 Fuel-injection apparatus having a common rail feeding several injectors F02M63/0003 takes precedence; Means for varying pressure in common rails; Pumps feeding common rails

Abstract

A method and system is provided of controlling a pump having a pumping element configured to provide pressurized fuel to a common rail accumulator coupled to a plurality of fuel injectors configured to inject fuel into a corresponding plurality of cylinders of an engine, comprising: receiving rail pressure values indicating a current fuel pressure in the accumulator; and responding to the received at least one rail pressure value by controlling operation of the pumping element during each potential pumping event of the pumping element to generate actual pumping events during at least some of the potential pumping events to cause the rail pressure values to remain within a desired range and to at least one of increase an overall efficiency of the pump, decrease audible noise generated by the pump, increase reliability of the pump and reduce injection pressure variations at the plurality of fuel injectors.

Claims

1. A method of controlling a pump having at least one pumping element configured to provide pressurized fuel to a common rail accumulator coupled to a plurality of fuel injectors configured to inject fuel into a corresponding plurality of cylinders of an engine, comprising:

receiving at least one rail pressure value indicating a current fuel pressure in the accumulator; and

responding to a received at least one rail pressure value by controlling operation of the at least one pumping element during each potential pumping event of the at least one pumping element to generate actual pumping events during at least some of the potential pumping events to cause the at least one rail pressure value to remain within a desired range or achieve a desired pressure value and to at least one of increase an overall efficiency of the pump or engine, decrease audible noise generated by the pump, increase reliability of the pump and reduce injection pressure variations at the plurality of fuel injectors.

2. The method of claim 1, wherein the at least one pumping element comprises two pumping elements.

3. The method of claim 2, wherein the two pumping elements are configured to have one of a 1×

, 1.5×

or 2×

ratio of potential pumping events to injection events by the plurality of fuel injectors.

4. The method of claim 2, wherein responding to the received at least one rail pressure value by controlling operation of the at least one pumping element comprises generating actual pumping events of either 100% fuel delivery or 0% fuel delivery during each of the potential pumping events to increase the overall efficiency of the pump.

5. The method of claim 2, wherein responding to the received at least one rail pressure value by controlling operation of the at least one pumping element comprises generating actual pumping events of either 100% fuel delivery or 0% fuel delivery during each of the potential pumping events of one of the pumping elements which is at a preferred phasing relative to the injection events and generating actual pumping events of 0% fuel delivery during all of the potential pumping events of another of the pumping elements which is not at the preferred phasing relative to the injection events, thereby decreasing audible noise generated by the pump or engine.

6. The method of claim 2, wherein responding to the received at least one rail pressure value by controlling operation of the at least one pumping element comprises generating actual pumping events of greater than 0% but less than 100% fuel delivery during each of the potential pumping events of one of the pumping elements which is at a preferred phasing relative to the injection events and generating actual pumping events of 0% fuel delivery during each of the potential pumping events of another of the pumping elements which is not at the preferred phasing relative to the injection events, thereby decreasing audible noise generated by the pump or engine.

7. The method of claim 2, wherein responding to the received at least one rail pressure value by controlling operation of the at least one pumping element comprises generating actual pumping events of 100% fuel delivery during each of the potential pumping events of one of the pumping elements which is at a preferred phasing relative to the injection events and generating actual pumping events of either 100% fuel delivery or 0% fuel delivery during the potential pumping events of another of the pumping elements which is not a the preferred phasing relative to the injection events, thereby increasing the overall efficiency of the pump and decreasing audible noise of the pump or engine.

8. The method of claim 2, wherein responding to the received at least one rail pressure value by controlling operation of the at least one pumping element comprises generating actual pumping events of 100% fuel delivery during each of the potential pumping events of one of the pumping elements which is at a preferred phasing relative to the injection events and generating actual pumping events of greater than 0% but less than 100% fuel delivery during each of the potential pumping events of another of the pumping elements which is not at the preferred phasing relative to the injection events.

9. The method of claim 2, wherein responding to the received at least one rail pressure value by controlling operation of the at least one pumping element comprises generating actual pumping events to deliver an amount of fuel that is greater than an undesirable fuel delivery percentage during half of the potential pumping events of one of the pumping elements which is at a preferred phasing relative to the injection events, generating actual pumping events to deliver an amount of fuel that is less than the undesirable fuel delivery percentage during another half of the potential pumping events of the one of the pumping elements which is at the preferred phasing relative to the injection events and generating actual pumping events of 0% fuel delivery during each of the potential pumping events of another of the pumping elements which is not at the preferred phasing relative to the injection events, thereby improving the reliability of the pump.

10. The method of claim 2, wherein responding to the received at least one rail pressure value by controlling operation of the at least one pumping element comprises generating actual pumping events to deliver either 0% fuel delivery or an amount of fuel that is greater than an undesirable fuel delivery percentage during each of the potential pumping events of one of the pumping elements which is at a preferred phasing relative to the injection events and during each of the potential pumping events of another of the pumping elements which is not at the preferred phasing relative to the injection events.

11. The method of claim 2, wherein responding to the received at least one rail pressure value by controlling operation of the at least one pumping element comprises generating actual pumping events to deliver either 0% fuel delivery or an amount of fuel that is greater than an undesirable fuel delivery percentage during each of the potential pumping events of one of the pumping elements which is at a preferred phasing relative to the injection events and generating actual pumping events of 0% fuel delivery during each of the potential pumping events of another of the pumping elements which is not at the preferred phasing relative to the injection events.

12. The method of claim 2, wherein responding to the received at least one rail pressure value by controlling operation of the at least one pumping element comprises generating actual pumping events of 100% fuel delivery during each of the potential pumping events of one of the pumping elements and generating actual pumping events of greater than 0% but less than 100% fuel delivery during each of the potential pumping events of another of the pumping elements.

13. The method of claim 2, wherein responding to the received at least one rail pressure value by controlling operation of the at least one pumping element comprises generating actual pumping events to deliver an amount of fuel that is greater than an undesirable fuel delivery percentage during each of the potential pumping events of one of the pumping elements and generating actual pumping events to deliver an amount of fuel that is less than the undesirable fuel delivery percentage during each of the potential pumping events of another of the pumping elements, thereby improving the reliability of the pump.

14. The method of claim 2, wherein responding to the received at least one rail pressure value by controlling operation of the at least one pumping element comprises generating actual pumping events of either 100% fuel delivery or 0% fuel delivery during each of the potential pumping events of one of the pumping elements and generating actual pumping events of 0% fuel delivery during each of the potential pumping events of another of the pumping elements.

15. The method of claim 14, wherein the actual pumping events of 100% fuel delivery are at a preferred phasing relative to the injection events, thereby decreasing audible noise of the pump or engine.

16. The method of claim 2, wherein responding to the received at least one rail pressure value by controlling operation of the at least one pumping element comprises generating actual pumping events of 100% fuel delivery during each of the potential pumping events of one of the pumping elements which are at a preferred phasing relative to the injection events, generating actual pumping events of greater than 0% but less than 100% fuel delivery during each of the potential pumping events of the one of the pumping elements which are not at the preferred phasing relative to the injection events, and generating actual pumping events of 0% fuel delivery during each of the potential pumping events of another of the pumping elements.

17. The method of claim 2, wherein responding to the received at least one rail pressure value by controlling operation of the at least one pumping element comprises generating actual pumping events to deliver an amount of fuel that is either less than or greater than an undesirable fuel delivery percentage during each of the potential pumping events of one of the pumping elements which are at a preferred phasing relative to the injection events and generating actual pumping events of 0% fuel delivery during each of the potential pumping events of the one of the pumping elements which are not at the preferred phasing relative to the injection events and during each of the potential pumping events of another of the pumping elements.

18. The method of claim 2, wherein responding to the received at least one rail pressure value by controlling operation of the at least one pumping element comprises generating actual pumping events during each of the potential pumping events to deliver an amount of fuel to the accumulator to cause rail pressure to be substantially the same at a start of each injection event.

19. The method of claim 2, wherein responding to the received at least one rail pressure value by controlling operation of the at least one pumping element comprises generating actual pumping events during each of the potential pumping events to deliver an amount of fuel to the accumulator to cause rail pressure to be substantially the same during each injection event.

20. A method of controlling a fuel pump having a plurality of pumping elements, comprising:

determining at least one of a desired rail pressure range or a desired rail pressure value;

determining a quantity of fuel to deliver during each potential pumping event corresponding to the plurality of pumping elements to at least one of maintain the rail pressure within the desired rail pressure range or near the desired rail pressure value and to increase pump efficiency, decrease audible noise generated by the pump, improve pump reliability, or reduce variation of rail pressure during fuel injection events; and

generating actual pumping events to deliver the determined quantity of fuel during each potential pumping event.

21. The method of claim 20, wherein generating actual pumping events comprises generating actual pumping events of either 100% fuel delivery or 0% fuel delivery to improve pump reliability.

22. The method of claim 20, wherein generating actual pumping events comprises generating actual pumping events during potential pumping events that are at a preferred phasing relative to injection events to decrease pump audible noise.

23. The method of claim 20, wherein generating actual pumping events comprises generating actual pumping events to deliver an amount of fuel that is greater than or less than an undesirable fuel delivery percentage to improve pump reliability.

24. The method of claim 20, wherein generating actual pumping events comprises generating actual pumping events to deliver an amount of fuel to cause rail pressure to be substantially the same at a start or during each injection event.

25. A fueling system, comprising:

a fuel pump comprises a plurality of pumping elements;

an accumulator coupled to the fuel pump;

a pressure sensor coupled to the accumulator, the pressure sensor configured to output a rail pressure value;

a plurality of fuel injectors coupled to the accumulator to receive pressurized fuel for delivery to an engine during injection events; and

a controller coupled to the fuel pump, the pressure sensor and the plurality of fuel injectors, the controller being configured to

determine a desired range of rail pressure values,

determine a quantity of fuel to deliver during each potential pumping event corresponding to the plurality of pumping elements to maintain the rail pressure value within the desired range and to increase fuel pump efficiency, decrease audible noise generated by the fuel pump, improve fuel pump reliability, or reduce variation of rail pressure values during fuel injection events, and

generate actual pumping events to deliver the determined quantity of fuel during each potential pumping event.