Fuel injector control system and method

Patent metadata

Field	Value
Publication number	US-2024392738-A1
Application number	US-202318324803-A
Country	US
Kind code	A1
Filing date	May 26, 2023
Priority date	May 26, 2023
Publication date	Nov 28, 2024
Grant date	—

Abstract

An electronically controlled fuel injector includes an injection valve; a control valve fluidly connected between a pressurized fuel supply passage and a control chamber for controlling operation of the injection valve, the control valve movable between a non-injection position and an injection position; the injection valve configured to inject fuel with the control valve in the injection position; and a control member chamber including an orifice that fluidly connects the control member chamber with a low pressure return line of a fuel supply system. The control chamber is fluidly coupled with a pressure communication passage such that the control chamber is fluidly coupled with the low pressure return line through the orifice in the control member chamber when the control valve is in the injection position. The pressure communication passage includes a two-way, variable flow rate valve.

First claim

What is claimed is:

1 . An electronically controlled fuel injector comprising:
an injection valve; a control valve fluidly connected between a pressurized fuel supply passage and a control chamber for controlling operation of the injection valve, the control valve movable between a non-injection position and an injection position; the injection valve configured to inject fuel with the control valve in the injection position; and a control member chamber including an orifice that fluidly connects the control member chamber with a low pressure return line of a fuel supply system, wherein the control chamber is fluidly coupled with a pressure communication passage that extends between the control chamber and the control member chamber such that the control chamber is fluidly coupled with the low pressure return line through the orifice in the control member chamber when the control valve is in the injection position, and wherein the pressure communication passage includes a two-way, variable flow rate valve that inhibits flow in a first direction through the two-way, variable flow rate valve and permits flow in a second direction through the two-way, variable flow rate valve to control an injection rate of the injection valve.

2 . The fuel injector of claim 1 , wherein the two-way, variable flow rate valve is configured to move between a restrictive position and a permissive position based on whether the control valve is in an injection position or a non-injection position.

3 . The fuel injector of claim 1 , wherein the two-way, variable flow rate valve includes a larger diameter channel and a smaller diameter channel, such that, when in the non-injection position, high pressure fuel is configured to pass through the larger diameter channel to port high pressure fuel to a top surface of the injection valve and, when in the injection position, fuel is configured to pass through the smaller diameter channel to port fuel through the orifice of the control member chamber to a return line of the fuel supply system.

4 . The fuel injector of claim 3 , wherein the smaller diameter channel is an orifice in an end face of the two-way, variable flow rate valve.

5 . The fuel injector of claim 2 , wherein the two-way, variable flow rate valve is configured to be in the permissive position at a beginning of injection.

6 . The fuel injector of claim 2 , wherein the two-way, variable flow rate valve is configured to be in the restrictive position at a beginning of injection.

7 . The fuel injector of claim 2 , wherein the two-way, variable flow rate valve is biased by gravity towards the permissive position.

8 . The fuel injector of claim 7 , wherein the two-way, variable flow rate valve is biased by a biasing mechanism against the force of gravity into the restrictive position.

9 . The fuel injector of claim 4 , wherein a flow path of high pressure fluid through the two-way, variable flow rate valve includes an approximately ninety-degree turn.

10 . The fuel injector of claim 1 , wherein the two-way, variable flow rate valve includes a central orifice that is cylindrical in shape.

11 . A fuel injector comprising:
an injection valve; a control valve fluidly connected between a pressurized fuel supply passage and a control chamber for controlling operation of the injection valve, the control valve movable between a non-injection position and an injection position; the injection valve configured to inject fuel with the control valve in the injection position; and a control member chamber including at least one orifice that fluidly connects the control member chamber with a low pressure return line of a fuel supply system, wherein the control member chamber comprises a primary volume and a throttling volume, the throttling volume being fluidly coupled with the low pressure return line of the fuel supply system.

12 . The fuel injector of claim 11 , wherein the throttling volume increases a total volume of the control member chamber by 50% as compared to the total volume of the control member chamber alone.

13 . The fuel injector of claim 12 , wherein the control member chamber is a cylindrical chamber generally below a control valve member.

14 . The fuel injector of claim 11 , wherein the throttling volume extends approximately parallel to the primary volume.

15 . The fuel injector of claim 12 , wherein the throttling volume includes two curved passages.

16 . The fuel injector of claim 15 , wherein the two curved passages are configured to leak fuel within a body of the fuel injector.

17 . A method of operating an engine system comprising:
operating a control valve that is fluidly connected between a pressurized fuel supply passage and a needle control chamber, operation including: providing high pressure fuel to the needle control chamber to keep a needle valve in place, preventing fuel injection through the needle valve; and allowing the high pressure fuel to escape the needle control chamber through a pressure communication passage to a control member chamber including an orifice that fluidly connects the control member chamber with a low pressure return line of a fuel supply system to fluidly connect the needle control chamber with the low pressure return line to allow the needle valve to perform a controlled opening; wherein the pressure communication passage includes a two-way, variable flow rate valve that inhibits flow in a first direction and permits flow in a second direction to control an injection rate of the injection valve, the variable flow rate valve including a larger diameter channel and a smaller diameter channel.

18 . The method of claim 17 , wherein the larger diameter channel and the smaller diameter channel are approximately perpendicular to each other.

19 . The method of claim 17 , wherein the smaller diameter channel is a channel formed in a bottom surface of the two-way, variable flow rate valve.

20 . The method of claim 17 , wherein the first direction and the second direction do not entirely overlap.

Assignees

• Caterpillar Inc

Inventors

• Pillarisetti Satya Naga Deepak
• Juchems Mitchell B
• Klein Pierson
• Wang Lifeng

Classifications

• F02M61/14

  Arrangements of injectors with respect to engines; Mounting of injectors · CPC title

• F02M61/04

  having valves {, e.g. having a plurality of valves in series} · CPC title

• F02D41/30 Primary

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

• F02M63/0056

  Throttling valves, e.g. having variable opening positions throttling the flow · CPC title

• F02M63/0054

  Check valves (F02M59/462, F02M59/464 take precedence) · CPC title