Pre-chamber spark plug for a combustion chamber of an internal combustion engine, in particular of a motor vehicle, and an internal combustion engine for a motor vehicle

Patent metadata

Field	Value
Publication number	US-11635017-B2
Application number	US-201816769495-A
Country	US
Kind code	B2
Filing date	Nov 28, 2018
Priority date	Dec 5, 2017
Publication date	Apr 25, 2023
Grant date	Apr 25, 2023

Abstract

A pre-chamber spark plug for a combustion chamber of an internal combustion engine has a pre-chamber which has a plurality of openings and which is fluidically connectable to the combustion chamber via the openings. Two spark gaps are arranged in the pre-chamber via which respective sparks can be formed. The spark gaps are arranged symmetrically distributed in the pre-chamber and a first of the spark gaps is arranged further outwards than the second spark gap along a direction extending perpendicularly to the longitudinal direction of the pre-chamber spark plug.

First claim

The invention claimed is:

1. A pre-chamber spark plug ( 18 ) for a combustion chamber ( 12 ) of an internal combustion engine ( 10 ), comprising:
a pre-chamber ( 20 ) which has a plurality of openings ( 22 , 24 ) and which is connectable fluidically to the combustion chamber ( 12 ) via the openings ( 22 , 24 ); and
a first spark gap ( 40 ) and a second spark gap ( 42 ) which are disposed in the pre-chamber ( 20 ) and via which respective ignition sparks are formable; wherein:
the first and second spark gaps ( 40 , 42 ) are arranged asymmetrically distributed in the pre-chamber ( 20 ) such that the first spark gap ( 40 ) is arranged further outwards with respect to a middle of the pre-chamber spark plug ( 18 ) than the second spark gap ( 42 ) along a direction ( 44 ) extending perpendicularly to a longitudinal direction ( 36 ) of the pre-chamber spark plug ( 18 ), and the second spark gap ( 42 ) is arranged closer to the middle of the pre-chamber spark plug ( 18 ) than the first spark gap ( 40 ) along the direction ( 44 ) extending perpendicularly to the longitudinal direction ( 36 ) of the pre-chamber spark plug ( 18 );
a central electrode ( 30 ), a ground electrode ( 32 ), and a housing ( 26 ), wherein the ground electrode ( 32 ) is integrally formed with the housing ( 26 ) of the pre-chamber spark plug ( 18 ) and extends from the housing ( 26 ) as an arm ( 58 ) toward the central electrode ( 30 ) and wherein the second spark gap ( 42 ) is formed between a first electrode region ( 60 ) formed by the arm ( 58 ) and a second electrode region ( 62 ) formed by the central electrode ( 30 );
the first spark gap ( 40 ) is formed between third and fourth electrode regions ( 52 , 54 ) and wherein the third and fourth electrode regions ( 52 , 54 ) have a first distance (A 1 ) from each other and the first and second electrode regions ( 60 , 62 ) have a second distance (A 2 ) from each other which is different from the first distance (A 1 );
the first and second distances (A 1 , A 2 ) differ from one another within a range of 0.05 millimeters to 0.15 millimeters inclusive;
at least respective tips (S) of the electrode regions ( 52 , 54 , 60 , 62 ) are formed of a precious metal;
respective passage directions ( 38 ) of at least two of the openings ( 22 ) run at an angle to the longitudinal direction ( 36 ) of the pre-chamber spark plug ( 18 ) and to the direction ( 44 ) extending perpendicularly to the longitudinal direction ( 36 ) of the pre-chamber spark plug ( 18 );
one of the openings ( 24 ) is a central opening; and
the at least two of the openings ( 22 ) are arranged distributed around the central opening in a circumferential direction of the pre-chamber spark plug ( 18 ).

2. An internal combustion engine for a motor vehicle, comprising:
a combustion chamber ( 12 ); and
the pre-chamber spark plug ( 18 ) according to claim 1 which is assigned to the combustion chamber.

Assignees

• Daimler Ag

Inventors

• Bertsch Dietmar

Classifications

• H01T13/467

  in parallel connection · CPC title

• H01T13/54 Primary

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

• F02P13/00

  Sparking plugs structurally combined with other parts of internal-combustion engines ({connection of ignition coil to spark plug connector F02P3/02;} with fuel injectors F02M57/06 {; spark plug connector per se H01T13/04 – H01T13/06; predominant aspects of sparking plug, see H01T13/40 – H01T13/44}) · CPC title

• F02B19/12

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

• F02P3/00

  Other installations · CPC title