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

Patent metadata

Field	Value
Publication number	US-11815006-B2
Application number	US-202117907920-A
Country	US
Kind code	B2
Filing date	Feb 17, 2021
Priority date	Mar 4, 2020
Publication date	Nov 14, 2023
Grant date	Nov 14, 2023

Abstract

A pre-chamber spark plug has a pre-chamber which has openings, where, with respect to a first plane running in the longitudinal direction of the pre-chamber and dividing the pre-chamber into two halves of equal size, first openings are disposed in a first of the halves and second openings are disposed in a second of the halves. The first openings are spaced apart from a second plane running in the longitudinal direction of the pre-chamber and extending perpendicular to the first plane by a first angle in the circumferential direction of the pre-chamber. The second openings are spaced apart from the second plane by a second angle in the circumferential direction of the pre-chamber. The mean value of the first angles is smaller than the mean value of the second angles.

First claim

The invention claimed is:

1. A pre-chamber spark plug ( 10 ) for a combustion chamber of an internal combustion engine, comprising:
a pre-chamber ( 12 ) which has a plurality of openings ( 16 , B 1 , B 2 ) and which is fluidically connectable to the combustion chamber via the plurality of openings ( 16 , B 1 , B 2 ), wherein a fuel-air mixture is introducible from the combustion chamber into the pre-chamber ( 12 ) via the plurality of openings ( 16 , B 1 , B 2 ) and wherein each of the plurality of openings ( 16 , B 1 , B 2 ) has a respective flow cross-section through which the fuel-air mixture is flowable;
wherein, with respect to an imaginary first plane (E 1 ) running in a longitudinal direction ( 24 ) of the pre-chamber ( 12 ) and dividing the pre-chamber ( 12 ) into a first half (H 1 ) and a second half (H 2 ) of equal size, first openings (B 1 ) of the plurality of openings ( 16 , B 1 , B 2 ) are disposed in the first half (H 1 ) and second openings (B 2 ) of the plurality of openings ( 16 , B 1 , B 2 ) are disposed in the second half (H 2 );
wherein the first openings (B 1 ) are spaced apart from an imaginary second plane (E 2 ) running in the longitudinal direction ( 24 ) of the pre-chamber ( 12 ), wherein the second plane (E 2 ) extends perpendicular to the imaginary first plane (E 1 ), by a first angle (ß 1 ) in a circumferential direction ( 28 ) of the pre-chamber ( 12 );
wherein the second openings (B 2 ) are spaced apart from the imaginary second plane (E 2 ) by a second angle (ß 2 ) in the circumferential direction ( 28 ) of the pre-chamber ( 12 );
wherein a mean value of the first angles (ß 1 ) is smaller than a mean value of the second angles (ß 2 ) such that the plurality of openings ( 16 , B 1 , B 2 ) are configured rotationally asymmetrically about an imaginary axis (A) running in the longitudinal direction ( 24 ) of the pre-chamber ( 12 ) in which the imaginary first and second planes (E 1 , E 2 ) intersect such that all of the plurality of openings ( 16 , B 1 , B 2 ) follow one another in an uneven or disordered manner which is not a regular sequence and such that the rotationally asymmetrical configuration of the plurality of openings ( 16 , B 1 , B 2 ) causes a tumble-shaped flow in the pre-chamber ( 12 ) of a fuel-air mixture that is introduced from the combustion chamber into the pre-chamber ( 12 ) via the plurality of openings ( 16 , B 1 , B 2 );
wherein the plurality of openings ( 16 , B 1 , B 2 ) are formed as bores; and/or
wherein the flow cross-sections of at least two of the plurality of openings ( 16 , B 1 , B 2 ) differ from each other with regard to a respective shape; and/or
the pre-chamber ( 12 ) is rotationally symmetrical with respect to the imaginary axis (A).

2. The pre-chamber spark plug ( 10 ) according to claim 1 , wherein the plurality of openings ( 16 , B 1 , B 2 ) are disposed along an imaginary circle, wherein a center of the imaginary circle lies on the imaginary axis (A), and wherein the imaginary first plane (E 1 ) divides the imaginary circle into two halves of equal size.

3. The pre-chamber spark plug ( 10 ) according to claim 1 , wherein a number of the first openings (B 1 ) disposed in the first half (H 1 ) is greater than a number of the second openings (B 2 ) disposed in the second half (H 2 ).

4. The pre-chamber spark plug ( 10 ) according to claim 1 , wherein a sum of the flow cross-sections of the first openings (B 1 ) disposed in the first half (H 1 ) is greater than a sum of the flow cross-sections of the second openings (B 2 ) disposed in the second half (H 2 ).

5. The pre-chamber spark plug ( 10 ) according to claim 4 , wherein the flow cross sections of the first openings (B 1 ) disposed in the first half (H 1 ) are larger than the flow cross sections of the second openings (B 2 ) disposed in the second half (H 2 ).

6. The pre-chamber spark plug ( 10 ) according to claim 4 , wherein a mean value of the flow cross-sections of the first openings (B 1 ) disposed in the first half (H 1 ) is greater than a mean value of the flow cross-sections of the second openings (B 2 ) disposed in the second half (H 2 ).

7. An internal combustion engine for a motor vehicle, comprising:
a combustion chamber; and
the pre-chamber spark plug ( 10 ) according to claim 1 .

8. A motor vehicle, comprising:
an internal combustion engine with a combustion chamber; and
the pre-chamber spark plug ( 10 ) according to claim 1 .

Assignees

• Mercedes Benz Group Ag

Inventors

• Holly Werner

Classifications

• F02B19/12 Primary

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

• F02B19/18

  Transfer passages between chamber and cylinder · CPC title

• F02B19/1014 Primary

  design parameters, e.g. volume, torch passage cross sectional area, length, orientation, or the like · CPC title

• F02B19/1019

  with only one pre-combustion chamber (F02B19/1004 take precedence) · CPC title

• F02B19/1023

  pre-combustion chamber and cylinder being fed with fuel-air mixture(s) · CPC title