Direct injection pump control

Patent metadata

Field	Value
Publication number	US-9957935-B2
Application number	US-201615221459-A
Country	US
Kind code	B2
Filing date	Jul 27, 2016
Priority date	Dec 4, 2014
Publication date	May 1, 2018
Grant date	May 1, 2018

Abstract

Methods are provided for controlling a solenoid spill valve of a direct injection fuel pump, wherein the solenoid spill valve is energized and de-energized according to certain conditions. An example control strategy is provided for operating the direct injection fuel pump when fuel vapor is detected at an inlet of the direct injection fuel pump. To ensure pump effectiveness during the presence of fuel vapor, the solenoid spill valve may be maintained energized for a minimum angular duration past a top-dead-center position of a piston in the direct injection fuel pump.

First claim

The invention claimed is:

1. A method, comprising:
energizing a solenoid spill valve of a direct injection fuel pump for or longer than a minimum angular duration based on a position of a piston in the direct injection fuel pump in response to fuel vapor detected at an inlet of the direct injection fuel pump.

2. The method of claim 1 , wherein the fuel vapor is detected based on a fuel capacitance.

3. The method of claim 2 , wherein the fuel capacitance is measured via a fuel composition sensor positioned downstream of a lift pump and upstream of the direct injection fuel pump, the lift pump supplying fuel to the direct injection fuel pump.

4. The method of claim 1 , wherein the solenoid spill valve is maintained energized until after a top-dead-center position of the piston is reached.

5. The method of claim 1 , wherein energizing the solenoid spill valve includes sending signals to the solenoid spill valve from a controller.

6. The method of claim 5 , wherein the controller further detects an angular position of a driving cam that powers the direct injection fuel pump in order to synchronize the energizing of the solenoid spill valve.

7. The method of claim 1 , further comprising, when the fuel vapor is not detected at the inlet of the direct injection fuel pump, energizing the solenoid spill valve for only an angular duration based on the position of the piston of the direct injection fuel pump.

8. The method of claim 7 , wherein energizing the solenoid spill valve for only the angular duration based on the position of the piston of the direct injection fuel pump comprises energizing the solenoid spill valve for less than the minimum angular duration.

9. The method of claim 7 , wherein, when the fuel vapor is not detected at the inlet of the direct injection fuel pump, the solenoid spill valve is maintained energized until a top-dead-center position of the piston is reached.

10. The method of claim 7 , wherein, when the fuel vapor is not detected at the inlet of the direct injection fuel pump, the solenoid spill valve is maintained energized until before a top-dead-center position of the piston is reached.

11. A system, comprising:
an engine including a cylinder;
a direct fuel injector coupled to the cylinder;
a direct injection fuel pump including a piston, a compression chamber, and a cam for driving the piston;
a high pressure fuel rail fluidically coupled to each of the direct fuel injector and an outlet of the direct injection fuel pump;
a solenoid spill valve fluidically coupled to an inlet of the direct injection fuel pump;
a lift pump fluidically coupled to the solenoid spill valve via a low pressure fuel line;
a fuel composition sensor coupled to the low pressure fuel line downstream of the lift pump and upstream of the solenoid spill valve; and
a controller with computer readable instructions stored in non-transitory memory for:
in response to detecting fuel vapor at the inlet of the direct injection fuel pump, energizing the solenoid spill valve for or longer than a minimum angular duration based on a position of the piston.

12. The system of claim 11 , wherein the controller comprises further instructions for, when the fuel vapor is not detected at the inlet of the direct injection fuel pump, energizing the solenoid spill valve for only an angular duration based on the position of the piston of the direct injection fuel pump.

13. The system of claim 12 , wherein, when the fuel vapor is not detected at the inlet of the direct injection fuel pump, de-energizing the solenoid spill valve before a top-dead-center position of the piston.

14. The system of claim 12 , wherein, when the fuel vapor is not detected at the inlet of the direct injection fuel pump, de-energizing the solenoid spill valve at a top-dead-center position of the piston.

15. The system of claim 11 , wherein the fuel vapor is detected based on a fuel capacitance, the fuel capacitance measured by the fuel composition sensor.

16. The system of claim 11 , wherein, when the fuel vapor is detected at the inlet of the direct injection fuel pump, de-energizing the solenoid spill valve after a top-dead-center position of the piston.

17. A method, comprising:
when a first condition is met, energizing a solenoid spill valve of a direct injection fuel pump for or longer than a minimum angular duration based on a position of a piston in the direct injection fuel pump; and
when the first condition is not met, energizing the solenoid spill valve for only an angular duration based on the position of the piston of the direct injection fuel pump.

18. The method of claim 17 , wherein, when the first condition is met, the solenoid spill valve is maintained energized until after a top-dead-center position of the piston, and wherein when the first condition is not met, the solenoid spill valve is maintained energized until before or at the top-dead-center position of the piston.

19. The method of claim 17 , wherein the first condition comprises a presence of fuel vapor at an inlet of the direct injection fuel pump, and wherein the presence of fuel vapor at the inlet is detected based on a fuel capacitance measured with a fuel composition sensor disposed downstream of a lift pump and upstream of the direct injection fuel pump.

20. The method of claim 17 , wherein energizing the solenoid spill valve includes sending signals to the solenoid spill valve from a controller, and wherein the controller further detects an angular position of a driving cam that powers the direct injection fuel pump in order to synchronize the energizing of the solenoid spill valve.

Assignees

• Ford Global Tech Llc

Inventors

• Pursifull Ross Dykstra

Classifications

• F02D41/3082

  Control of electrical fuel pumps · CPC title

• F02D41/26

  using computer, e.g. microprocessor · CPC title

• F02D2200/0611

  Fuel type, fuel composition or fuel quality · CPC title

• F02D41/30 Primary

  Controlling fuel injection {(F02D41/182, F02D41/24 take precedence)} · CPC title

• F02M59/34

  by throttling of passages to pumping elements or of overflow passages {, e.g. throttling by means of a pressure-controlled sliding valve having liquid stop or abutment} · CPC title