Abstract: A prechamber spark plug having a thermally enhanced prechamber cap with a thermally conductive core, such as one made from a copper-, aluminum- and/or silver-based material. Due to its location and function, a prechamber cap is exposed to thermal energy from a pre-combustion process taking place within a prechamber, as well as thermal energy from a combustion process taking place in a main combustion chamber. Thus, the prechamber cap is being heated on both its interior and its exterior and, if not sufficiently cooled, can become so hot that it undesirably triggers preignition events in the engine. The thermally enhanced prechamber cap may include a main body with an interior surface and an exterior surface, a thermally conductive core with one or more thermal segments and insert segments, and one or more openings extending between a prechamber and a main combustion chamber, where each opening extends through an insert segment that is designed to resistant to corrosion and/or erosion.

Abstract: A prechamber spark plug that includes an internal reservoir, a flow passage portion, and a prechamber and is designed to operate efficiently across a wide variety of operating conditions and ranges. The internal reservoir includes upper and lower internal reservoir sections, the prechamber includes upper and lower prechamber sections, and the flow passage portion fluidly connects the lower internal reservoir section and the upper prechamber section so that burnt air/fuel gases can be exchanged therebetween. A ground electrode assembly with a ground electrode ring may be positioned in the prechamber such that it separates the upper and lower prechamber sections, whereas a modular prechamber cap may be used to define the shape and size of the lower prechamber section. In one example, the flow passage portion has a total cross-sectional area (AFC) and the internal reservoir has a total volume (VRES), and the ratio AFC:VRES is greater than or equal to 0.015 (1/mm).

Abstract: A prechamber spark plug having a thermally enhanced prechamber cap with a thermally conductive core, such as one made from a copper-, aluminum- and/or silver-based material. Due to its location and function, a prechamber cap is exposed to thermal energy from a pre-combustion process taking place within a prechamber, as well as thermal energy from a combustion process taking place in a main combustion chamber. Thus, the prechamber cap is being heated on both its interior and its exterior and, if not sufficiently cooled, can become so hot that it undesirably triggers preignition events in the engine. The thermally enhanced prechamber cap may include a main body with an interior surface and an exterior surface, a thermally conductive core with one or more thermal segments and insert segments, and one or more openings extending between a prechamber and a main combustion chamber, where each opening extends through an insert segment that is designed to resistant to corrosion and/or erosion.