Pre-Chamber Spark Plug for a Combustion Chamber of a Combustion Engine, Combustion Engine, and Motor Vehicle

Abstract

A pre-chamber spark plug for a combustion chamber of a combustion engine includes a pre-chamber which has a plurality of openings and an electrode device which is disposed in the pre-chamber. An ignition spark for igniting a fuel-air mixture introduced into the pre-chamber is generatable at a spark location in the pre-chamber by the electrode device. The pre-chamber spark plug is configured to bring about a tumble-shaped flow of fuel-air mixture flowing into the pre-chamber via the plurality of openings. The tumble-shaped flow has, in a first region of the pre-chamber, a first flow part pointing upward away from the plurality of openings, and, in a second region of the pre-chamber, a second flow part adjoining the first flow part and pointing downward in a direction of the plurality of openings. The spark location is disposed at least in part in the second region.

Claims

1.-8. (canceled)

9. A pre-chamber spark plug (10) for a combustion chamber of a combustion engine, comprising: a pre-chamber (12) which has a plurality of openings (16) and which is fluidically connectable to the combustion chamber via the plurality of openings (16), wherein a fuel-air mixture is introducible from the combustion chamber into the pre-chamber (12) via the plurality of openings (16); and an electrode device (18) which is disposed in the pre-chamber (12), wherein an ignition spark for igniting fuel-air mixture introduced into the pre-chamber (12) is generatable at a spark location (O) in the pre-chamber (12) by the electrode device (18); wherein the pre-chamber spark plug (10) is configured to bring about a tumble-shaped flow (26) of fuel-air mixture flowing into the pre-chamber (12) via the plurality of openings (16); wherein each of the plurality of openings (16) has a respective flow cross-section through which the fuel-air mixture is flowable; wherein the tumble-shaped flow (26) comprises, in a first region (B1) of the pre-chamber (12), a first flow part (T1) pointing upward away from the plurality of openings (16) and, in a second region (B2) of the pre-chamber (12), a second flow part (T2) adjoining the first flow part (T1) and pointing downward in a direction of the plurality of openings (16); wherein the spark location (O) is disposed at least in part in the second region (B2); wherein the plurality of openings (16) are formed as bores; wherein the flow cross-sections of at least two of the plurality of openings (16) differ from each other with regard to a respective shape; wherein the plurality of openings (16) are disposed along an imaginary circle, wherein a center of the imaginary circle lies on an imaginary axis, wherein an imaginary plane in which the imaginary axis runs splits the imaginary circle into a first half and a second half of equal size, and wherein a sum of the flow cross-sections of first openings of the plurality of openings (16) disposed in the first half is greater than a sum of the flow cross-sections of second openings of the plurality of openings (16) disposed in the second half; and wherein the pre-chamber (12) is rotationally symmetrical with respect to the imaginary axis.

10. The pre-chamber spark plug (10) according to claim 9, wherein the plurality of openings (16) are configured to bring about the tumble-shaped flow (26).

11. The pre-chamber spark plug (10) according to claim 9, wherein the imaginary axis runs in a longitudinal direction of the pre-chamber (12).

12. The pre-chamber spark plug (10) according to claim 9, wherein the flow cross-sections of the first openings disposed in the first half are larger than the flow cross-sections of the second openings disposed in the second half.

13. The pre-chamber spark plug (10) according to claim 9, wherein the flow cross sections of the first openings disposed in the first half are larger than the flow cross sections of the second openings disposed in the second half.

14. The pre-chamber spark plug (10) according to claim 12, wherein the plurality of openings (16) are circular such that the plurality of openings (16) each have a diameter and wherein the diameters of the first openings disposed in the first half are greater than the diameters of the second openings disposed in the second half.

15. A combustion engine for a motor vehicle, comprising: a combustion chamber; and the pre-chamber spark plug (10) according to claim 9.

16. A motor vehicle, comprising: a combustion engine with a combustion chamber; and the pre-chamber spark plug (10) according to claim 9.

Description

BRIEF DESCRIPTION OF THE DRAWING

[0033] The drawing shows, in the sole FIGURE, a schematic and sectional side view of a pre-chamber spark plug according to the invention for a combustion chamber of a combustion engine of a motor vehicle.

DETAILED DESCRIPTION OF THE DRAWING

[0034] The sole FIGURE shows, in a schematic and sectional side view, a pre-chamber spark plug 10 for a combustion chamber, formed for example by a cylinder or as a cylinder or delimited by a cylinder, of a combustion engine, formed for example as a reciprocating piston engine, of a motor vehicle, in particular a motor car, such as a passenger car or commercial vehicle. The motor vehicle can be driven by means of the combustion engine. The pre-chamber spark plug 10 has at least one or exactly one pre-chamber 12, the contour of which is denoted by 14 in FIG. 1. The pre-chamber 12 has a plurality of openings 16, also referred to as nozzles and formed in the present case as through-openings, via which the pre-chamber 12 is fluidically connected to the combustion chamber. In its fully manufactured state, the combustion engine has the aforementioned combustion chamber and the pre-chamber spark plug 10, so that in the fully manufactured state of the combustion engine, the pre-chamber spark plug 12 is fluidically connected to the combustion chamber via the openings 16. As a result, a fuel-air mixture, also referred to simply as a mixture, from the combustion chamber, can at least partially flow through the openings 16 and can thus flow into the pre-chamber 12, so that at least part of the fuel-air mixture, also referred to simply as a mixture, from the combustion chamber can flow through the openings 16 and can thus flow into the pre-chamber 12 via the openings 16.

[0035] The pre-chamber spark plug 10 furthermore has an electrode device 18, which is arranged at least in part in the pre-chamber 12. The electrode device 19 comprises a first electrode 20 and a second electrode 22, wherein the electrodes 20 and 22, in particular their corresponding free ends E1, and E2, are arranged in the pre-chamber 12. The ends E1 and E2, which are arranged in the pre-chamber 12, are distanced here from one another and consequently do not touch. The first electrode 20, for example, is a so-called middle electrode, wherein the second electrode 22, for example, is a so-called ground electrode. At least one or precisely one ignition spark can be generated by means of the electrodes 20 and 22 and thus by means of the electrode device 18, in particular during fired operation and within each cycle of the combustion engine, at least at or precisely at a spark location O in the pre-chamber 12. The mixture, which has passed into the pre-chamber 12 via the openings 16, is ignited by means of the ignition spark and is subsequently burned. It can be seen from the FIGURE that the electrodes 20 and 22, in particular their ends E1 and E2, define, delimit or bound the spark location O for the ignition spark, also referred to as the ignition location. For example, the spark location O is at least partially, in particular at least predominantly or completely, between the electrodes 20 and 22, in particular between the ends E1 and E2. Expressed again in other words, the ignition spark is created at the spark location O, or the ignition spark spreads out from the spark location. This means in particular that, by means of the electrodes 20 and 22, the at least one ignition spark can be provided at the spark location O, also referred to as the spark location, in the pre-chamber 12. Burning flares result from the ignition and the resultant burning of the mixture in the pre-chamber 12 and flow through the openings 16 and thus flow out of the pre-chamber 12 and into the combustion chamber via the openings 16. As a result, for example, a further part of the mixture remaining in the combustion chamber is ignited and subsequently burned, thus driving the aforementioned piston.

[0036] The pre-chamber spark plug 10, in particular the openings 16, is or are now configured to bring about a tumble-shaped flow of the mixture flowing into the pre-chamber 12 via the openings 16, shown in the FIGURE by arrows 24 and 26 and also referred to as a cylindrical flow, cylinder flow or tumble flow. This means that the tumble-shaped flow of the mixture occurs or takes place at least in the pre-chamber 12. In particular, the arrows 24 and 26 shown in FIG. 1 show a contour of the tumble-shaped flow also referred to as a flow contour.

[0037] Furthermore, it can be seen in particular with reference to the arrow 26 that the tumble-shaped flow taking place or occurring in the pre-chamber 12 comprises a flow part T1 which points away upwardly from the openings 16 and which is arranged or occurs in a first region B1 of the pre-chamber 12. In addition, the tumble-shaped flow comprises a second flow part T2, which adjoins the first flow part T1, points downwardly in the direction of the openings 16, and is arranged or occurs, runs or takes place in a second region B2 of the pre-chamber 12. It can also be seen from the FIGURE that the region B1 is a first half and the region B2 is a second half of the pre-chamber 12, wherein the halves are of equal size. Here, the pre-chamber 12 for example is divided into the regions B1 and B2 by an imaginary, or virtual parting plane E, in which a or the main axis of the pre-chamber spark plug 10 or pre-chamber 12 runs. The pre-chamber 12 is, for example, at least substantially rotationally symmetrical with respect to the main axis. A plurality of first openings 16 are arranged for example in the first half of the pre-chamber 12, wherein second openings 16 are arranged in the second half of the pre-chamber 12.

[0038] The parting plane E runs, for example, perpendicularly to a further cylinder plane shown in the FIGURE, with the main axis also running in the plane. Here, the tumble-shaped flow runs in a tumble shape in the stated cylinder plane. Due to the tumble-shaped flow, a volume V of the pre-chamber 12, also referred to as the dead volume, can be kept particularly low, so that a particularly large operating region of the pre-chamber spark plug 10 can be ensured. Furthermore, axes of the various openings 16 are denoted in the FIGURE by 28. For example, each opening 16 is rotationally symmetrical with respect to its particular axis 28 and is also circular, for example, so that, for example, the axis 28 in question runs in the longitudinal direction of the corresponding opening 16. The axis 28 in question coincides with a corresponding direction of passage along which the mixture can flow from the combustion chamber through the corresponding opening 16 and thus into the pre-chamber 12. In addition, for example, the particular flare resulting from the ignition of the mixture in the pre-chamber 12 can flow through the corresponding opening 16 and thus flow out of the pre-chamber 12 into the combustion chamber. In this case, the opening 16 in question has a corresponding flow cross-section, through which the flare in question or the mixture can flow. In particular, if the opening 16 in question is circular or is embodied as or by a cylindrical bore, the flow cross-section in question, also referred to as the cross-section, of the corresponding opening 16 formed for example as a bore can be characterized by the diameter of the latter and can be circular here. In addition, an electrode region EB can be seen in the FIGURE, in which the electrodes 20 and 22, in particular their ends E1 and E2 and/or the spark location O are arranged.

[0039] The tumble flow referred to as a cylindrical flow has a flow center which is orthogonal to the main axis of the pre-chamber 12 and runs for example in the plane E. In particular, the flow center is a cylinder axis which runs orthogonal to the cylinder plane. The tumble flow runs cylindrically here around the cylinder axis, which for example runs in the parting plane E and perpendicularly to the main axis of the pre-chamber 12. In other words, the tumble flow can be defined as a flow structure in which the flow of the mixture flows in the second region B2 away from the bores in the direction of the electrode region EB and thus flows upward or in an upwardly directed manner to the electrodes 20 and 22, which is also referred to as an upward flow, then flows through the electrode region EB and then flows in the region B1 away from the electrode region EB in the direction of the bores and thus downward, which is also referred to as the downward direction. Thus, the tumble flow is a structured flow form, which, however, is not rotationally symmetrical to the pre-chamber main axis.

LIST OF REFERENCE CHARACTERS

[0040] 10 pre-chamber spark plug [0041] 12 pre-chamber [0042] 14 contour [0043] 16 opening [0044] 18 electrode device [0045] 20 electrode [0046] 22 electrode [0047] 24 arrow [0048] 26 arrow [0049] 28 axis [0050] O spark location [0051] B1, B2 region [0052] E parting plane [0053] EB electrode region [0054] E1, E2 end [0055] T1, T2 flow part [0056] V volume