Abstract: A spark plug with a longitudinal axis. The spark plug includes a housing with a hole along the spark plug longitudinal axis and a combustion-chamber-side end side, wherein the housing has a recess on the end side thereof; an insulator arranged inside the housing; a central electrode arranged inside the insulator; and a ground electrode arranged in one of the recesses on the housing end side; wherein the ground electrode and the central electrode are arranged such that an ignition gap is formed within the housing.

Abstract: A spark plug having a longitudinal axis. The spark plug includes: a housing; an insulator disposed at least partly inside the housing; a center electrode disposed at least partly inside the insulator and has an electrode body and an ignition element that is disposed on the combustion chamber-side end of the electrode body and serves as an ignition surface, wherein the ignition element has a cylindrical shape with a round base and a longitudinal axis which extends parallel to the spark plug longitudinal axis; and at least one ground electrode having an ignition surface disposed inside the housing on the housing. The ground electrode and the center electrode are disposed such that they form a spark gap that extends radially with respect to the spark plug longitudinal axis, wherein a width of the spark gap is not greater than 0.3 mm. The spark gaps are completely inside the housing.

Abstract: An internal combustion engine. The internal combustion engine includes: at least one cylinder in which a combustion chamber is formed, the combustion chamber being delimited by side walls of the cylinder and a combustion chamber roof, which is formed by a cylinder head of the cylinder, and a piston that can move in the cylinder; and a spark plug with a longitudinal axis including: a housing with a combustion chamber-facing end face, an insulator disposed in the housing, a center electrode disposed in the insulator, and at least one ground electrode disposed on or in the housing and, together with the center electrode, forms at least one spark gap. The spark plug is mounted in a bore formed in the cylinder head and is designed to ignite a fuel/air mixture in the combustion chamber. The spark gap of the spark plug is located outside the combustion chamber.

Abstract: A spark plug having a longitudinal axis. The spark plug includes: a housing having a bore along the spark plug longitudinal axis and a combustion-chamber-side end face; an insulator arranged at least partially within the housing, and having an insulator base extending from a combustion-chamber-side end face of the insulator to an insulator base neck; a central electrode arranged at least partially within the insulator; and a ground electrode arranged on the housing, the ground electrode and the central electrode being arranged so that the at least one ground electrode forms a spark gap with the central electrode, a width of the spark gap being defined by an inter-electrode distance between the central electrode and the ground electrode. The inter-electrode distance between the central electrode and the ground electrode is not greater than 0.4 mm. The spark gap is formed at least partially within the housing.

Abstract: A spark plug including a housing, an insulator, a center electrode, and a ground electrode situated at a combustion chamber-side end of the housing. The insulator has an insulator collar, an insulator base, and a transition area, which rests on a projection of the housing. A breathing space is configured at the combustion chamber-side end of the spark plug and is delimited by a section of the inner side of the housing and a section of the insulator base. The section of the insulator base has a rounding including a first leg length and a second leg length angled with respect to the first leg length, the first leg length extending between the intersecting point of the leg lengths with one another and a first end point of the rounding, and the second leg length extending between the intersecting point and a second end point of the rounding.

Abstract: A spark plug including a housing, an insulator, a center electrode, and a ground electrode situated at a combustion chamber-side end of the housing. The insulator has an insulator collar, an insulator base, and a transition area, which rests on a projection of the housing. A breathing space is configured at the combustion chamber-side end of the spark plug and is delimited by a section of the inner side of the housing and a section of the insulator base. The section of the insulator base has a rounding including a first leg length and a second leg length angled with respect to the first leg length, the first leg length extending between the intersecting point of the leg lengths with one another and a first end point of the rounding, and the second leg length extending between the intersecting point and a second end point of the rounding.