The present invention pertains to a spark plug for an internal combustion engine, comprising a metal outer shell extending in a longitudinal direction from a proximal end to a distal tip end configured to be oriented towards a combustion chamber, said outer shell comprising a fixation portion for attachment of the spark plug to a metal sleeve of the internal combustion engine and arranged at a region proximal of the tip end, wherein the outer shell furthermore comprises a first contact surface arranged at a region distal of the fixation portion and configured to contact a distal end of the sleeve, when the spark plug is attached to the sleeve.

A spark plug of an internal combustion engine has a sealing area between a mounting portion (e.g., threads) and an end portion of a housing of the spark plug. The end portion faces a combustion chamber of the internal combustion engine. The spark plug includes a flow control element coupled to the end portion, wherein the flow control element projects beyond an igniter in a direction toward the combustion chamber.

A spark plug of an internal combustion engine has a sealing area between a mounting portion (e.g., threads) and an end portion of a housing of the spark plug. The end portion faces a combustion chamber of the internal combustion engine. The spark plug includes a flow control element coupled to the end portion, wherein the flow control element projects beyond an igniter in a direction toward the combustion chamber.

A spark plug for use with an engine block/cylinder head having a threaded bore and also for use with a spark plug wrench and an ignition wire. Also, an improved method for constructing a spark plug, the spark plug including a metal shell having a hex nut, a seat, a flange, a bore and threads. A ground electrode is associated with the shell and an insulator assembly occupies the bore and is gripped by the flange. The method includes the steps of forming the hex nut and the seat by carrying out operations on a blank, roiling the threads, fitting the insulator assembly into the bore, deforming the flange to capture the insulator, and forming the negative electrode by machining the blank.

A spark plug for use with an engine block/cylinder head having a threaded bore and also for use with a spark plug wrench and an ignition wire. Also, an improved method for constructing a spark plug, the spark plug including a metal shell having a hex nut, a seat, a flange, a bore and threads. A ground electrode is associated with the shell and an insulator assembly occupies the bore and is gripped by the flange. The method includes the steps of forming the hex nut and the seat by carrying out operations on a blank, roiling the threads, fitting the insulator assembly into the bore, deforming the flange to capture the insulator, and forming the negative electrode by machining the blank.

A spark plug inspection method and a spark plug manufacturing method that enable evaluation for the position of a ground electrode of a tapered-seat-type spark plug. The spark plug inspection method includes: a contact step of screwing an external thread of a metal shell to an internal thread of a gauge so as to bring a part of a tapered portion of the metal shell into line-contact or point-contact with an inner edge of the gauge; and a determination step of determining whether or not a ground electrode is present within a predetermined range in a circumferential direction of the gauge when the tapered portion comes into line-contact or point-contact with the inner edge of the gauge in the contact step.

A housing for a spark plug. The housing includes a bore along the longitudinal axis X of the housing, as the result of which the housing has an outer side and an inner side, and an electroplated or chemically applied nickel-containing protective layer situated on at least one portion of the outer side of the housing and a sealing layer situated on the nickel-containing protective layer. The sealing layer contains silicon. A first intermediate layer is applied between the housing and the nickel-containing protective layer and/or a second intermediate layer is applied between the nickel-containing protective layer and the sealing layer and/or a cover layer is applied on the sealing layer. The sealing layer may be free of chromium.

A housing for a spark plug. The housing includes a bore along the longitudinal axis X of the housing, as the result of which the housing has an outer side and an inner side, and an electroplated or chemically applied nickel-containing protective layer situated on at least one portion of the outer side of the housing and a sealing layer situated on the nickel-containing protective layer. The sealing layer contains silicon. A first intermediate layer is applied between the housing and the nickel-containing protective layer and/or a second intermediate layer is applied between the nickel-containing protective layer and the sealing layer and/or a cover layer is applied on the sealing layer. The sealing layer may be free of chromium.

An igniter seal arrangement for a combustion chamber. The combustion chamber has a wall having first surface and second surfaces. A boss projects from the first surface, and has a platform on its remote end. The platform has an inner surface spaced from the first surface of the wall to define a chamber between the first surface of the wall and the inner surface of the platform. The platform has an outer surface facing away from the first surface of the wall and an aperture extends through the wall from the outer surface of the platform of the boss to the second surface. First and second L-shape rails extend from the platform and a sealing member has a first edge and a second edge locatable between the outer surface of the platform and the first and second L-shape rails and the sealing member has an aperture to receive an igniter.

An igniter seal arrangement for a combustion chamber. The combustion chamber has a wall having first surface and second surfaces. A boss projects from the first surface, and has a platform on its remote end. The platform has an inner surface spaced from the first surface of the wall to define a chamber between the first surface of the wall and the inner surface of the platform. The platform has an outer surface facing away from the first surface of the wall and an aperture extends through the wall from the outer surface of the platform of the boss to the second surface. First and second L-shape rails extend from the platform and a sealing member has a first edge and a second edge locatable between the outer surface of the platform and the first and second L-shape rails and the sealing member has an aperture to receive an igniter.