Laser ignition device and operating method therefor

Patent metadata

Field	Value
Publication number	US-9784173-B2
Application number	US-201314395864-A
Country	US
Kind code	B2
Filing date	Mar 18, 2013
Priority date	Apr 23, 2012
Publication date	Oct 10, 2017
Grant date	Oct 10, 2017

Abstract

A laser ignition device for an internal combustion engine, in which the laser ignition device has at least one laser spark plug and a cooling device for temperature control, in particular cooling, of the laser spark plug. The cooling device has a cooling circuit, containing a coolant, which is thermally connectable to at least one component of the laser spark plug, a volume of the coolant contained in the cooling circuit being less than or equal to approximately 50% of a compression volume of a cylinder of the internal combustion engine, which may be less than or equal to approximately 10% of a compression volume of the cylinder of the internal combustion engine.

First claim

What is claimed is:

1. A laser ignition device for an internal combustion engine, comprising:
at least one laser spark plug; and
a cooling device for temperature control for cooling of the laser spark plug;
wherein the cooling device has a cooling circuit, containing a coolant, which is thermally connectable to at least one component of the laser spark plug, and wherein a volume of the coolant contained in the cooling circuit is less than or equal to approximately 50% of a compression volume of a cylinder of the internal combustion engine.

2. A laser ignition device for an internal combustion engine of a motor vehicle, comprising:
at least one laser spark plug; and
a cooling device for temperature control for cooling of the laser spark plug;
wherein the cooling device has a cooling circuit containing a coolant, which is thermally connectable to at least one component of the laser spark plug, and wherein a volume of the coolant contained in the cooling circuit is less than or equal to approximately 0.1 L.

3. The laser ignition device of claim 1 , wherein the cooling circuit has a first heat exchanger, which is thermally connectable to at least one component of the laser spark plug, the cooling circuit having a second heat exchanger which is thermally connectable to a heat sink, and having a conveyance arrangement to cause a circulation of the coolant in the cooling circuit.

4. The laser ignition device of claim 1 , wherein the cooling circuit has at least one fluid line for guiding the coolant.

5. The laser ignition device of claim 4 , wherein at least one fluid line has an internal diameter of at most approximately 4 mm.

6. The laser ignition device of claim 4 , wherein an aggregate total length of all fluid lines of the cooling circuit is at most approximately 4 m.

7. The laser ignition device of claim 1 , wherein the cooling circuit has a flow rate of coolant per unit of time of at least approximately 2 mL per minute.

8. The laser ignition device of claim 1 , wherein at least one of at least one fluid line for guiding the coolant and a conveyance arrangement for the coolant are at least partially integrated into a wiring harness of the laser spark plug.

9. The laser ignition device of claim 1 , wherein at least one of at least one fluid line for guiding the coolant and a conveyance arrangement for the coolant are at least partially thermally insulated in relation to the surroundings.

10. The laser ignition device of claim 1 , wherein the cooling circuit is configured to be closed.

11. An internal combustion engine, comprising:
at least one laser ignition device, including:
at least one laser spark plug; and
a cooling device for temperature control for cooling of the laser spark plug;
wherein the cooling device has a cooling circuit, containing a coolant, which is thermally connectable to at least one component of the laser spark plug, and wherein a volume of the coolant contained in the cooling circuit is less than or equal to approximately 50% of a compression volume of a cylinder of the internal combustion engine.

12. A method for operating a laser ignition device for an internal combustion engine, comprising:
using at least one laser ignition device, which includes at least one laser spark plug, and a cooling device for temperature control for cooling of the laser spark plug;
operating the cooling device, which has a cooling circuit, containing a coolant, which is thermally connectable to at least one component of the laser spark plug, and wherein a volume of the coolant contained in the cooling circuit is less than or equal to approximately 50% of a compression volume of a cylinder of the internal combustion engine.

13. A method for operating a laser ignition device for an internal combustion engine of a motor vehicle, the method comprising:
using at least one laser ignition device, which includes at least one laser spark plug and a cooling device for temperature control for cooling of the laser spark plug; and
operating the cooling device, which has a cooling circuit containing a coolant, which is thermally connectable to at least one component of the laser spark plug, and wherein a volume of the coolant contained in the cooling circuit is less than or equal to approximately 0.1 L.

14. The laser ignition device of claim 1 , wherein the volume of the coolant contained in the cooling circuit is less than or equal to approximately 10% of a compression volume of a cylinder of the internal combustion engine.

15. The laser ignition device of claim 2 , wherein the volume of the coolant contained in the cooling circuit is less than or equal to approximately 0.05 L.

16. The laser ignition device of claim 1 , wherein the cooling circuit has at least one fluid line for guiding the coolant, the fluid line being configured to be flexible.

17. The laser ignition device of claim 16 , wherein at least one fluid line has an internal diameter of at most approximately 3 mm.

18. The laser ignition device of claim 4 , wherein an aggregate total length of all fluid lines of the cooling circuit is at most approximately 2 m.

19. The laser ignition device of claim 1 , wherein the cooling circuit has a flow rate of coolant per unit of time of at least approximately 50 mL per minute.

20. The method of claim 12 , wherein the volume of the coolant contained in the cooling circuit is less than or equal to approximately 10% of a compression volume of a cylinder of the internal combustion engine.

21. The method of claim 13 , wherein the volume of the coolant contained in the cooling circuit is less than or equal to approximately 0.05 L.

Assignees

• Bosch Gmbh Robert

Inventors

• Stoppel Klaus

Classifications

• F02F1/4214

  specially adapted for four or more valves per cylinder · CPC title

• H01S3/0407

  Liquid cooling, e.g. by water · CPC title

• F02P23/04

  Other physical ignition means, e.g. using laser rays · CPC title

• F02F1/242

  Arrangement of spark plugs or injectors · CPC title

• F01P3/16 Primary

  for cooling fuel injectors or sparking-plugs · CPC title