SPARK PLUG FOR REMOVING RESIDUAL EXHAUST GAS AND ASSOCIATED COMBUSTION CHAMBER

• US 20130206101A1
• Filed: 12/07/2012
• Published: 08/15/2013
• Est. Priority Date: 02/09/2012
• Status: Active Grant

• Current Assignee: Cummins Incorporated
• Original Assignee: Cummins Incorporated
• Inventors: Douglas, Keith J., Qin, Xiao, O'Connor, Daniel J., Sasidharan, Premjee
• Granted Patent: US 9,225,151 B2
• Time in Patent Office: Days
• US Class Current: 123/260
• CPC Class Codes: F02B 19/12 with positive ignition engines with non-timed positive ignition, and with incandescent chambers F02B9/08
• CPC Class Codes: H01T 13/32 characterised by features of the earthed electrode
• CPC Class Codes: H01T 13/46 having two or more spark gaps
• CPC Class Codes: H01T 13/467 in parallel connection
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

A spark plug, and associated systems, for an internal combustion engine includes a central electrode that terminates at a first distal end surface defined about a central axis. The spark plug also includes at least one outer electrode that terminates at a second distal end surface. The at least one outer electrode at least partially laterally surrounds the central electrode such that the second distal end surface is radially offset relative to the central electrode and a lateral gap is defined between the central electrode and the at least one outer electrode. The spark plug include features that force or redirect movement of the flow of the fresh air-fuel mixture through the lateral gap to help to purge or move the residual exhaust gases left over from a previous combustion event out of the lateral gap.

Claims

1. A spark plug for an internal combustion engine, comprising:

a central electrode terminating at a first distal end surface defined about a central axis; and

at least one outer electrode terminating at a second distal end surface, the at least one outer electrode at least partially laterally surrounding the central electrode such that the second distal end surface is radially offset relative to the central electrode and a lateral gap is defined between the central electrode and the at least one outer electrode;

wherein the first distal end surface of the central electrode is axially recessed relative to the second distal end surface of the at least one outer electrode.

2. The spark plug of claim 1, wherein the first distal end surface of the central electrode and the second distal end surface of the at least one outer electrode are substantially co-planar.

3. The spark plug of claim 1, wherein the spark plug comprises a plurality of outer electrodes.

4. The spark plug of claim 1, wherein the first distal end surface of the central electrode is recessed up to about one millimeter relative to the second distal end surface of the at least one outer electrode.

5. The spark plug of claim 1, wherein the central electrode comprises a cylindrical head that defines the first distal end surface, the central electrode further comprising a stem supporting the head relative to the at least one outer electrode such that the lateral gap is defined between the head of the central electrode and the at least one outer electrode.

6. A spark plug for an internal combustion engine, comprising:

a central electrode terminating at a first distal end surface defined about a central axis;

at least one outer electrode terminating at a second distal end surface, the at least one outer electrode at least partially laterally surrounding the central electrode such that the second distal end surface is radially offset relative to the central electrode and a lateral gap is defined between the central electrode and the at least one outer electrode; and

at least one pad coupled to the second distal end surface of the at least one outer electrode, wherein a third distal end surface of the at least one pad is axially offset relative to the first distal end surface of the central electrode.

7. The spark plug of claim 6, wherein the spark plug comprises a plurality of outer electrodes and a plurality of pads, wherein each of the plurality of outer electrodes is coupled to a respective one of the plurality of pads.

8. The spark plug of claim 6, wherein spark plug comprises a plurality of outer electrodes and only two pads each coupled to a respective two of the plurality of outer electrodes.

9. The spark plug of claim 8, wherein the respective two of the plurality of outer electrodes with pads coupled thereto are adjacent each other.

10. The spark plug of claim 8, wherein the respective two of the plurality of outer electrodes with pads coupled thereto are on opposing sides of the at least one outer electrode.

11. The spark plug of claim 6, wherein the at least one outer electrode is made from a first material and the at least one pad is made from a second material different than the first material.

12. A spark plug for an internal combustion engine, comprising:

a central electrode terminating at a first distal end surface defined about a central axis, the central electrode comprising at least one elongate channel formed in the first distal end surface; and

at least one outer electrode terminating at a second distal end surface, the at least one outer electrode at least partially laterally surrounding the central electrode such that the second distal end surface is radially offset relative to the central electrode and a lateral gap is defined between the central electrode and the at least one outer electrode.

13. The spark plug of claim 12, wherein the central electrode comprises at least two elongate channels formed in the first distal end surface.

14. The spark plug of claim 13, wherein the at least two elongate channels extend diametrically across the first distal end surface perpendicularly relative to each other.

15. A spark plug for an internal combustion engine, comprising:

a central electrode terminating at a first distal end surface defined about a central axis, the central electrode comprising a plurality of notches formed in the first distal end surface about an outer periphery of the first distal end surface; and

at least one outer electrode terminating at a second distal end surface, the at least one outer electrode at least partially laterally surrounding the central electrode such that the second distal end surface is radially offset relative to the central electrode and a lateral gap is defined between the central electrode and the at least one outer electrode.

16. The spark plug of claim 15, wherein each of the plurality of notches are substantially wedge shaped.

17. The spark plug of claim 15, wherein the plurality of notches are spaced an equal distance apart from each other about the outer periphery of the first distal end surface.

18. A spark plug for an internal combustion engine, comprising:

a central electrode terminating at a first distal end surface defined about a central axis; and

at least one outer electrode terminating at a second distal end surface, the at least one outer electrode at least partially laterally surrounding the central electrode such that the second distal end surface is radially offset relative to the central electrode and a lateral gap is defined between the central electrode and the at least one outer electrode;

wherein at least one of the first distal end surface of the central electrode and the second distal end surface of the at least one outer electrode is tapered.

19. The spark plug of claim 18, wherein the first distal end surface of the central electrode is tapered.

20. The spark plug of claim 19, wherein the first distal end surface of the central electrode is tapered at an angle relative to the second distal end surface of the at least one outer electrode, and wherein the angle is between about 1-degree and about 25-degrees.

21. The spark plug of claim 18, wherein the second distal end surface of the at least one outer electrode is tapered.

22. The spark plug of claim 21, wherein the second distal end surface of the at least one outer electrode is tapered at an angle relative to the first distal end surface of the central electrode, and wherein the angle is between about 1-degree and about 25-degrees.

23. The spark plug of claim 18, wherein the first distal end surface of the central electrode is tapered and the second distal end surface of the at least one outer electrode is tapered.

24. A pre-chamber apparatus for use with an internal combustion engine having a cylinder head coupled to a cylinder block, the cylinder head comprising a spark plug recess and the cylinder block comprising a main combustion chamber open to the spark plug recess, and wherein the cylinder head further comprises a fire deck surface facing the main combustion chamber, the pre-chamber apparatus comprising:

an insert positionable within and securely mateable with the spark plug recess, the insert comprising a distal end surface, an interior chamber, and at least one channel extending between the interior chamber and the distal end surface, wherein when positioned within and securely mated with the spark plug recess, the distal end surface of the insert is substantially flush with the fire deck surface of the cylinder head; and

a spark plug comprising cathode and anode electrodes, the spark plug being coupleable to the insert such that at least a portion of the electrodes of the spark plug are positioned within the interior chamber of the insert.

25. The pre-chamber apparatus of claim 24, wherein the insert comprises external threads that are threadably engageable with internal threads of the spark plug recess to securely mate the insert with the spark plug recess.

26. The pre-chamber apparatus of claim 24, wherein the insert comprises a plurality of channels extending between the interior chamber and the distal end surface.