Abstract: A batch of spark plugs. Each spark plug has a longitudinal axis, a central electrode oriented in the direction of the longitudinal axis, a ground electrode oriented at an angle to the longitudinal axis, such that a spark gap is formed between a tip of the central electrode and a tip of the ground electrode, and an outer thread for screwing the spark plug in the longitudinal direction into an inner thread of a cylinder head of a combustion chamber of an internal combustion engine, and has an annular contact surface oriented perpendicularly to the longitudinal axis and intended for bringing the spark plug to rest against the cylinder head. After the spark plugs have been screwed into the inner thread of the cylinder head, the ground electrodes have the same orientation with regard to a rotation about the longitudinal axis of the spark plug relative to the combustion chamber.

Abstract: A prechamber spark plug, including center and ground electrodes, a housing having an external thread, a cap arranged on the housing and together with the housing defines a prechamber, and an insulator which electrically insulates the center electrode from the housing. The external thread has a thread length in the axial direction. The housing is fastened to the insulator at first and second fixing regions so that a first clamping force at the first fixing region acts from the housing on the insulator, and a second clamping force at the second fixing region acts from the housing on the insulator. The first and second clamping forces are directed in opposite directions to one another in the axial direction. A distance between the first and second fixing regions in the axial direction defines a clamping length. A ratio between the thread length and the clamping length is between 0.7 to 1.3.

Abstract: A prechamber spark plug, including center and ground electrodes, a housing having an external thread, a cap arranged on the housing and together with the housing defines a prechamber, and an insulator which electrically insulates the center electrode from the housing. The external thread has a thread length in the axial direction. The housing is fastened to the insulator at first and second fixing regions so that a first clamping force at the first fixing region acts from the housing on the insulator, and a second clamping force at the second fixing region acts from the housing on the insulator. The first and second clamping forces are directed in opposite directions to one another in the axial direction. A distance between the first and second fixing regions in the axial direction defines a clamping length. A ratio between the thread length and the clamping length is between 0.7 to 1.3.

Abstract: A pre-chamber spark plug includes (i) a middle electrode with a first noble metal body which has a first end spark face, (ii) a ground electrode with a second noble metal body which has a second end spark face, (iii) a housing, with the ground electrode being fixed in the housing, (iv) an insulator which electrically insulates the middle electrode with respect to the ground electrode, and (v) a cap, which together with a part of the housing, defines a pre-chamber. The first end spark face and the second end spark face are arranged oppositely at a distance from one another.

Abstract: A method for manufacturing a prechamber spark plug including an external thread and a cap including at least one through-opening. The method includes: providing the prechamber spark plug without a cap and including a cylindrical circumferential surface for the external thread. Mounting the cap, which includes at least one through-opening, in an arbitrary alignment at the prechamber spark plug, and creating the external thread at the circumferential surface in such a way that a thread start and/or a thread end of the external thread is aligned in relation to the through-opening at a predetermined position.

Abstract: A prechamber spark plug. The spark plug includes a housing, a cap, which defines a prechamber at least partially, and which includes a plurality of through holes that are configured to produce a connection between the prechamber and a combustion chamber of an internal combustion engine; the through holes each having a hole center line; the cap including a recess at a region pointed towards the housing, the recess abutting the housing at a combustion-chamber-side end of the housing; a distance from an exit point of a through hole lying on the hole center line, to a recess, being in a range of 2 mm to 7 mm; and a first angle between a center axis of the prechamber spark plug and the hole center line being in a range of 30° to 70°. An internal combustion engine including such a prechamber spark plug is also described.

Abstract: A batch of spark plugs. Each spark plug has a longitudinal axis, a central electrode oriented in the direction of the longitudinal axis, a ground electrode oriented at an angle to the longitudinal axis, such that a spark gap is formed between a tip of the central electrode and a tip of the ground electrode, and an outer thread for screwing the spark plug in the longitudinal direction into an inner thread of a cylinder head of a combustion chamber of an internal combustion engine, and has an annular contact surface oriented perpendicularly to the longitudinal axis and intended for bringing the spark plug to rest against the cylinder head. After the spark plugs have been screwed into the inner thread of the cylinder head, the ground electrodes have the same orientation with regard to a rotation about the longitudinal axis of the spark plug relative to the combustion chamber.

Abstract: A method for manufacturing a prechamber spark plug including an external thread and a cap including at least one through-opening. The method includes: providing the prechamber spark plug without a cap and including a cylindrical circumferential surface for the external thread. Mounting the cap, which includes at least one through-opening, in an arbitrary alignment at the prechamber spark plug, and creating the external thread at the circumferential surface in such a way that a thread start and/or a thread end of the external thread is aligned in relation to the through-opening at a predetermined position.

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.

Abstract: A prechamber spark plug for an internal combustion engine with the following features: a body with an external thread at its front end for screwing the spark plug into the engine; the external thread has a center line and begins with a thread start at the front end; the body has a passage in which an insulator is fastened and a center electrode protrudes from the front end of this insulator; at the front end of the body, a prechamber-forming cap is provided, which delimits a prechamber and shields the center electrode from a combustion chamber of the engine after the spark plug has been installed in the engine; the cap has at least one opening, which has a predefined orientation in relation to the thread start and is oriented obliquely to the center line of the external thread so as to permit a gas exchange between the prechamber and the space outside the prechamber.

Abstract: A pre-chamber spark plug for an internal combustion engine having: a body with a passage in which an insulator is fastened and a center electrode protrudes; at least one ground electrode extending in a straight line forms a spark gap with the center electrode; a pre-chamber-forming cap which delimits a pre-chamber and shields the center and ground electrodes from a combustion chamber after the spark plug has been installed in the engine, wherein the cap has at least one opening which permits a gas exchange between the pre-chamber and the space outside the pre-chamber. The ground electrode includes a reinforcing component welded to an end surface of a supporting component, and the supporting component is either welded to an end surface of the body or is welded to a step that is formed on the end surface.

Abstract: An internal combustion engine having: a housing with at least one cylinder and a pre-chamber spark plug; the cylinder has a piston that is able to move in the housing and delimits a combustion chamber contained in the housing; the combustion chamber has a compressed volume when the piston is at top dead center; the pre-chamber spark plug has a body, an external thread at its front end, a passage, an insulator positioned in the passage, a center electrode protruding from the front end of the insulator, and a pre-chamber-forming cap that is placed at the front end of the body and delimits a pre-chamber. The cap shields the center electrode from the combustion chamber and has at least one opening, which enables a gas exchange between the pre-chamber and the combustion chamber. In one embodiment, the total volume of the pre-chamber makes up at least 0.65% of the compressed volume of the combustion chamber.

Abstract: A system composed of a water sleeve and a spark plug for an internal combustion engine. The spark plug has a supply passage, a center conductor, an insulator surrounding the center conductor, and a metallic body surrounding the insulator. A center electrode and at least one ground electrode form a spark air gap. In the region of its front end, the spark plug has an external thread for screwing the spark plug into a component of the internal combustion engine and has at least one discharge opening of the supply passage. The spark plug, at its front end, has, attached to the body, a sleeve that contains the external thread; the body has, on its outside, at least one groove that forms a section of the supply passage; and the sleeve has a heat conducting section that contains at least a part of the external thread and that is in contact with the body and covers at least portions of the groove.

Abstract: A method for producing an electrode device for a spark plug, with the following steps: preparation of an electrode body composed of a first material, the electrode body having a first joining surface; preparation of a precious metal part, which has a second joining surface; placement of the joining surfaces against each other and production of a relative movement between the joining surfaces during which the joining surfaces are pressed against each other with a first force (F1) that is less than a force threshold (FS); termination of the relative movement and pressing of the joining surfaces against each other for a pressing period (TA) with a second force (F2) that is greater than the force threshold (FS) in such a way that a diffusion from the first and/or second material beyond the joining surfaces takes place; and termination of the pressing together, wherein the relative movement is a linear movement and/or an orbital movement.

Abstract: A method for producing an electrode device for a spark plug, with the following steps: preparation of an electrode body composed of a first material, the electrode body having a first joining surface; preparation of a precious metal part, which has a second joining surface; placement of the joining surfaces against each other and production of a relative movement between the joining surfaces during which the joining surfaces are pressed against each other with a first force (F1) that is less than a force threshold (FS); termination of the relative movement and pressing of the joining surfaces against each other for a pressing period (TA) with a second force (F2) that is greater than the force threshold (FS) in such a way that a diffusion from the first and/or second material beyond the joining surfaces takes place; and termination of the pressing together, wherein the relative movement is a linear movement and/or an orbital movement.

Abstract: A system composed of a water sleeve and a spark plug for an internal combustion engine. The spark plug has a supply passage, a center conductor, an insulator surrounding the center conductor, and a metallic body surrounding the insulator. A center electrode and at least one ground electrode form a spark air gap. In the region of its front end, the spark plug has an external thread for screwing the spark plug into a component of the internal combustion engine and has at least one discharge opening of the supply passage. The spark plug, at its front end, has, attached to the body, a sleeve that contains the external thread; the body has, on its outside, at least one groove that forms a section of the supply passage; and the sleeve has a heat conducting section that contains at least a part of the external thread and that is in contact with the body and covers at least portions of the groove.

Abstract: A prechamber spark plug for a gas-powered internal combustion engine, having a metallic body, an insulator, a center electrode, at least one ground electrode, a cap, and a sleeve. The cap is arranged at a front end of the spark plug and shields the center and ground electrodes from a combustion chamber after the prechamber spark plug is installed in the internal combustion engine, and the cap delimits a prechamber in which the center electrode and the ground electrode are located from the combustion chamber. The cap has at least one opening that permits gas exchange between the prechamber and the space outside of the prechamber. The cap is mounted on the sleeve, which surrounds a section of the body, contains external threads for screwing into the internal combustion engine, and is joined to the body. In addition, a method for manufacturing the aforementioned spark plug is described.

Abstract: A pre-chamber spark plug for an internal combustion engine having: a body with a passage in which an insulator is fastened and a center electrode protrudes; at least one ground electrode extending in a straight line forms a spark gap with the center electrode; a pre-chamber-forming cap which delimits a pre-chamber and shields the center and ground electrodes from a combustion chamber after the spark plug has been installed in the engine, wherein the cap has at least one opening which permits a gas exchange between the pre-chamber and the space outside the pre-chamber. The ground electrode includes a reinforcing component welded to an end surface of a supporting component, and the supporting component is either welded to an end surface of the body or is welded to a step that is formed on the end surface.

Abstract: An internal combustion engine having: a housing with at least one cylinder and a pre-chamber spark plug; the cylinder has a piston that is able to move in the housing and delimits a combustion chamber contained in the housing; the combustion chamber has a compressed volume when the piston is at top dead center; the pre-chamber spark plug has a body, an external thread at its front end, a passage, an insulator positioned in the passage, a center electrode protruding from the front end of the insulator, and a pre-chamber-forming cap that is placed at the front end of the body and delimits a pre-chamber. The cap shields the center electrode from the combustion chamber and has at least one opening, which enables a gas exchange between the pre-chamber and the combustion chamber. In one embodiment, the total volume of the pre-chamber makes up at least 0.65% of the compressed volume of the combustion chamber.