Passive prechamber spark plug

Patent metadata

Field	Value
Publication number	US-11815005-B2
Application number	US-202117798827-A
Country	US
Kind code	B2
Filing date	Jan 14, 2021
Priority date	Feb 11, 2020
Publication date	Nov 14, 2023
Grant date	Nov 14, 2023

Abstract

A passive prechamber spark plug for use in a combustion chamber of a vehicle engine includes an upper prechamber having an upper opening where the upper prechamber is connectable to the combustion chamber via the upper opening. An air ignition spark is formable via an upper air spark gap. A central electrode is disposed in an upper region of the upper prechamber where a base of the upper prechamber opposite the upper region is an insulator. An electrically conductive element or a slot is guided by the insulator continuously from the upper prechamber into a lower region under the base and the lower region is either a lower prechamber or is arrangeable directly in the combustion chamber. An earth electrode is disposed in the lower region such that a lower air-surface gap spark gap is formed between the earth electrode and the electrically conductive element or the slot.

First claim

The invention claimed is:

1. A passive prechamber spark plug for use in a combustion chamber of a vehicle engine, comprising:
an upper prechamber having a plurality of upper openings arranged annularly around the upper prechamber and disposed in a prechamber sleeve which is a metal outer sleeve, wherein the upper prechamber is connectable to the combustion chamber via the plurality of upper openings;
an upper air spark gap, wherein an air ignition spark is formable via the upper air spark gap;
a central electrode disposed in an upper region of the upper prechamber;
a lower region under the upper prechamber, wherein the lower region is either a lower prechamber or is arrangeable directly in the combustion chamber;
an insulator, wherein the insulator is a separating wall disposed between the upper prechamber and the lower region and wherein the insulator is a base of the upper prechamber;
an electrically conductive element or a slot, wherein the electrically conductive element or the slot is disposed in the insulator; and
an earth electrode disposed in the lower region such that a lower air-surface gap spark gap is formed between the earth electrode and the electrically conductive element or the slot, wherein an air-surface gap ignition spark is formable via the lower air-surface gap spark gap.

2. The passive prechamber spark plug according to claim 1 , wherein:
the lower region is the lower prechamber;
the lower prechamber has a plurality of lower openings arranged annularly around the lower prechamber and disposed in the prechamber sleeve which is the metal outer sleeve, wherein the lower prechamber is connectable to the combustion chamber via the plurality of lower openings;
the insulator is a ceiling of the lower prechamber; and
the electrically conductive element or the slot, and the earth electrode, are disposed such that the upper air spark gap and the lower air-surface gap spark gap are disposed in series relative to each other.

3. The passive prechamber spark plug according to claim 1 , wherein:
the lower region is arrangeable directly in the combustion chamber; and
the electrically conductive element or the slot, and the earth electrode, are disposed such that the upper air spark gap and the lower air-surface gap spark gap are disposed in series relative to each other.

4. The passive prechamber spark plug according to claim 1 , wherein the electrically conductive element is a metal insertion component.

5. The passive prechamber spark plug according to claim 3 , wherein a width of the slot is substantially smaller than a spacing between the earth electrode and the upper opening.

6. The passive prechamber spark plug according to claim 5 , wherein the width of the slot corresponds to a hairline crack.

7. The passive prechamber spark plug according to claim 1 , wherein the insulator is an insulating ceramic material.

8. A vehicle engine, comprising:
the passive prechamber spark plug according to claim 1 .

Assignees

• Bayerische Motoren Werke Ag

Inventors

• Drees Rainer

Classifications

• F02B19/12 Primary

  with positive ignition (engines with non-timed positive ignition, and with incandescent chambers F02B9/08) · CPC title

• F02B19/165 Primary

  The shape or construction of the pre-combustion chambers is specially adapted to be formed, at least in part, of ceramic material (surface coverings of combustion-gas-swept parts F02B77/02; shaped ceramic products characterised by their composition or ceramic compositions C04B35/00; ceramic material for engine casings F02F7/0087) · CPC title

• H01T13/462

  in series connection · CPC title

• H01T13/52

  characterised by a discharge along a surface · CPC title

• H01T13/54

  having electrodes arranged in a partly-enclosed ignition chamber · CPC title