Ignitor for natural gas engine

Patent metadata

Field	Value
Publication number	US-11326507-B2
Application number	US-202117365781-A
Country	US
Kind code	B2
Filing date	Jul 1, 2021
Priority date	Jan 22, 2020
Publication date	May 10, 2022
Grant date	May 10, 2022

Abstract

In one aspect, an engine ignition apparatus for a natural gas engine may include a housing including a drive piston, a floating piston, a controllable hydraulic fluid chamber located between the drive piston and the floating piston, and an ignition chamber acted on by the floating piston, the ignition chamber having an outlet formed by a plurality of orifices, the outlet being in direct communication with a combustion chamber of the engine. In another aspect, an engine ignition apparatus for a natural gas engine may include, among other features, a controllable valve connected to a hydraulic fluid chamber, and configured to open and release a hydraulic fluid from the hydraulic fluid chamber, and to close. In still another aspect, a method for controlling an engine ignition apparatus for an engine includes, among other features, controlling a volume of a hydraulic fluid chamber of an ignition apparatus.

First claim

What is claimed is:

1. A method for controlling an engine ignition apparatus for an engine, the method comprising:
driving a drive piston to move a floating piston;
controlling a volume of a hydraulic fluid chamber of the ignition apparatus between the drive piston and the floating piston; and
compressing an air-fuel mixture in an ignition chamber of the ignition apparatus by movement of the floating piston, the air-fuel mixture being configured to ignite when compressed to a threshold pressure.

2. The method of claim 1 , further comprising directly communicating the ignition chamber with a combustion chamber through an outlet of the ignition chamber.

3. The method of claim 1 , wherein the floating piston isolates the hydraulic fluid chamber from the ignition chamber of the ignition apparatus.

4. The method of claim 1 , wherein the controlling of the volume of the hydraulic fluid chamber includes controlling an opening timing and a closing timing of a valve of the ignition apparatus using a controller of the engine.

5. The method of claim 4 , wherein the opening timing and the closing timing of the valve are controlled based on an engine load map.

6. The method of claim 4 , wherein the opening timing and the closing timing of the valve are controlled based on an engine requirement, including one or more of a pressure signal, or an exhaust gas temperature signal from the natural gas engine.

7. The method of claim 4 , wherein, while the valve is open, the volume of the hydraulic fluid in the hydraulic fluid chamber decreases as the hydraulic fluid flows through the valve.

8. A method for controlling an engine ignition apparatus for an engine, the method comprising:
driving a drive piston to move a floating piston;
compressing an air-fuel mixture in an ignition chamber of the ignition apparatus by movement of the floating piston, the air-fuel mixture being configured to ignite when compressed to a threshold pressure; and
directly communicating the ignition chamber with a combustion chamber through an outlet of the ignition chamber.

9. The method of claim 8 , wherein the floating piston isolates a hydraulic fluid chamber from the ignition chamber of the ignition apparatus.

10. The method of claim 9 , further comprising controlling a volume of the hydraulic fluid chamber by controlling an opening timing and a closing timing of a valve of the ignition apparatus using a controller of the engine.

11. The method of claim 9 , wherein the opening timing and the closing timing of the valve are controlled based on an engine load map.

12. The method of claim 9 , wherein the opening timing and the closing timing of the valve are controlled based on an engine requirement, including one or more of a pressure signal, or an exhaust gas temperature signal from the natural gas engine.

13. The method of claim 9 , wherein, while the valve is open, the volume of the hydraulic fluid in the hydraulic fluid chamber decreases as the hydraulic fluid flows through the valve.

14. A method for operating an ignition apparatus for a natural gas engine having a housing including a drive piston, a floating piston, a controllable hydraulic fluid chamber located between the drive piston and the floating piston, and an ignition chamber acted on by the floating piston, the ignition chamber having an outlet formed by a plurality of orifices, the outlet being in direct communication with a combustion chamber of the engine, the method comprising:
driving the drive piston to move the floating piston;
controlling a volume of the hydraulic fluid chamber; and
compressing an air-fuel mixture in the ignition chamber by movement of the floating piston, the air-fuel mixture being configured to ignite when compressed to a threshold pressure.

15. The method of claim 14 , wherein the floating piston isolates the hydraulic fluid chamber from the ignition chamber of the ignition apparatus.

16. The method of claim 14 , wherein the ignition apparatus further includes a valve connected to the hydraulic fluid chamber.

17. The method of claim 16 , wherein the controlling the volume of the hydraulic fluid chamber includes controlling an opening timing and a closing timing of the valve.

18. The method of claim 17 , wherein the opening timing and the closing timing of the valve are controlled based on an engine load map.

19. The method of claim 17 , wherein the opening timing and the closing timing of the valve are controlled based on an engine requirement, including one or more of a pressure signal, or an exhaust gas temperature signal from the natural gas engine.

20. The method of claim 17 , wherein, while the valve is open, the volume of the hydraulic fluid in the hydraulic fluid chamber decreases as the hydraulic fluid flows through the valve.

Assignees

• Caterpillar Inc

Inventors

• Chang David Y

Classifications

• F02B3/06

  with compression ignition (compression ignition engines using air or gas for blowing fuel into compressed air in cylinder F02B13/02) · CPC title

• F02B19/06

  with auxiliary piston in chamber for transferring ignited charge to cylinder space · CPC title

• F02B2075/125

  Direct injection in the combustion chamber for spark ignition engines, i.e. not in pre-combustion chamber · CPC title

• F02M26/01 Primary

  Internal exhaust gas recirculation, i.e. wherein the residual exhaust gases are trapped in the cylinder or pushed back from the intake or the exhaust manifold into the combustion chamber without the use of additional passages · CPC title

• Y02T10/30

  Use of alternative fuels, e.g. biofuels · CPC title