A prechamber spark plug. The prechamber spark plug includes a housing and a cap, which is arranged at a combustion-chamber end of the prechamber spark plug. The cap has, on the combustion-chamber side, a recess in an outer side.

A prechamber spark plug. The prechamber spark plug includes a housing and a cap, which is arranged at a combustion-chamber end of the prechamber spark plug. The cap has, on the combustion-chamber side, a recess in an outer side.

A prechamber spark plug having a housing, which at its front end comprises a prechamber with an ignition electrode arranged therein, wherein the ignition electrode comprises a base and electrode legs protruding from the base, wherein the ignition electrode is machined from a sheet made of an iridium alloy and the legs are bent out of the plane of the base to form a basket shape, characterized in that the ignition electrode, in particular the electrode legs, is/are separated out of the sheet metal by means of laser cutting. Furthermore, a corresponding ignition electrode and a method for producing such an ignition electrode are claimed.

A prechamber spark plug having a housing, which at its front end comprises a prechamber with an ignition electrode arranged therein, wherein the ignition electrode comprises a base and electrode legs protruding from the base, wherein the ignition electrode is machined from a sheet made of an iridium alloy and the legs are bent out of the plane of the base to form a basket shape, characterized in that the ignition electrode, in particular the electrode legs, is/are separated out of the sheet metal by means of laser cutting. Furthermore, a corresponding ignition electrode and a method for producing such an ignition electrode are claimed.

A spark plug for an internal combustion engine includes insulating glass having a tubular shape, a central electrode including a tip protruding portion, a housing having a tubular shape, and a plug cover provided over an auxiliary combustion chamber. The plug cover is provided with injection holes through which the auxiliary combustion chamber communicates with the exterior. The central electrode includes a base material and a core material disposed inside the base material and having a higher thermal conductivity than the base material. The core material includes a large diameter portion and a small diameter portion continuously formed on a tip side of the large diameter portion. The small diameter portion has a smaller diameter than the large diameter portion, and includes, in a part of the small diameter portion in an axial direction, a small-diameter columnar portion having a constant diameter. At least a part of the small-diameter columnar portion is disposed further on the tip side of the spark plug than a tip of the insulating glass.

A spark plug for an internal combustion engine includes insulating glass having a tubular shape, a central electrode including a tip protruding portion, a housing having a tubular shape, and a plug cover provided over an auxiliary combustion chamber. The plug cover is provided with injection holes through which the auxiliary combustion chamber communicates with the exterior. The central electrode includes a base material and a core material disposed inside the base material and having a higher thermal conductivity than the base material. The core material includes a large diameter portion and a small diameter portion continuously formed on a tip side of the large diameter portion. The small diameter portion has a smaller diameter than the large diameter portion, and includes, in a part of the small diameter portion in an axial direction, a small-diameter columnar portion having a constant diameter. At least a part of the small-diameter columnar portion is disposed further on the tip side of the spark plug than a tip of the insulating glass.

A pre-chamber spark plug includes a shell extending along a longitudinal axis and comprising an inner surface. The pre-chamber spark plug further includes an insulator including an outer surface. The pre-chamber spark plug further includes a pre-chamber cap connected to the shell. The pre-chamber cap and the shell together forms a pre-chamber. The pre-chamber spark plug further includes an annular reservoir defined between the outer surface of the insulator and the inner surface of the shell. The annular reservoir is spaced apart from the pre-chamber with respect to the longitudinal axis. The pre-chamber spark plug further includes a plurality of projections disposed between the annular reservoir and the pre-chamber with respect to the longitudinal axis. The plurality of projections at least partially define a plurality of flow passages therebetween.

A pre-chamber spark plug includes a shell extending along a longitudinal axis and comprising an inner surface. The pre-chamber spark plug further includes an insulator including an outer surface. The pre-chamber spark plug further includes a pre-chamber cap connected to the shell. The pre-chamber cap and the shell together forms a pre-chamber. The pre-chamber spark plug further includes an annular reservoir defined between the outer surface of the insulator and the inner surface of the shell. The annular reservoir is spaced apart from the pre-chamber with respect to the longitudinal axis. The pre-chamber spark plug further includes a plurality of projections disposed between the annular reservoir and the pre-chamber with respect to the longitudinal axis. The plurality of projections at least partially define a plurality of flow passages therebetween.

A spark plug includes: a cylindrical insulator; a center electrode that is held on an inner circumferential side of the insulator and includes a tip-end protruding portion that protrudes from the insulator toward a tip end side; a cylindrical housing that holds the insulator on an inner circumferential side; and a plug cover that is provided in a tip end portion of the housing so as to cover a pre-combustion chamber in which the tip-end protruding portion is arranged. The plug cover is provided with an injection hole that communicates the pre-combustion chamber to the outside. A positioning portion that performs positioning of the housing and the plug cover in a plug circumferential direction is provided in the housing and the plug cover.

A spark plug includes: a cylindrical insulator; a center electrode that is held on an inner circumferential side of the insulator and includes a tip-end protruding portion that protrudes from the insulator toward a tip end side; a cylindrical housing that holds the insulator on an inner circumferential side; and a plug cover that is provided in a tip end portion of the housing so as to cover a pre-combustion chamber in which the tip-end protruding portion is arranged. The plug cover is provided with an injection hole that communicates the pre-combustion chamber to the outside. A positioning portion that performs positioning of the housing and the plug cover in a plug circumferential direction is provided in the housing and the plug cover.