Abstract: In an ignition coil for an internal combustion engine, a column section and a notched section are provided in a side wall section of a case section of the ignition coil. A ventilation opening is formed in an up/down direction in the column section. The ventilation opening communicates with a ventilation passage formed between a sealing rubber and the case section and is open in an upper end section. A cover surrounding the column section and covering the upper end section is provided in the side wall section. A sealing section sealing the notched section is provided in the cover. The ignition coil has a filler resin that fills a space within the case section being in continuous contact with the sealing section and the side wall section and fixing the cover to the side wall section.

Abstract: An ignition coil for the internal combustion engine has a cylinder portion and a head portion. A pillar portion that forms a part of a ventilation passage that communicates inside and outside of a plug hole via a sealing member, and a cover portion that covers the pillar portion without blockading an upper opening of a ventilation opening of the pillar portion are formed on a side of the head portion.

Abstract: An ignition coil for an internal combustion engine includes a primary coil formed by winding a primary winding a plurality of turns, a secondary coil formed by winding a secondary winding having a wire diameter of 30 to 100 ?m a plurality of turns, and a resin compact which is impregnated into between the lines of the primary winding and between the lines of the secondary winding and which seals the primary coil and the secondary coil. The resin compact includes a filler in a range of 65 weight percent to 80 weight percent in order to limit development of an electric tree in the resin compact, and the filler is composed of 60 weight percent or more spherical silica and 40 weight percent or less crushed silica.

Abstract: An ignition coil includes a coil body, a plug connection portion protruding from the coil body, and a connector for electrically connecting the ignition coil to an outside. In the coil body, a primary coil is arranged on an inner peripheral side of a secondary coil, and a center core is arranged on an inner peripheral side of the primary coil. The secondary coil includes a secondary electric wire having thereon an insulating film, wound around an outer periphery of a resinous secondary spool. Furthermore, the connector is formed integrally with an end of the secondary spool in an axial direction.

Abstract: An ignition coil includes a coil body transversely arranged outside of a plug hole, and a plug connection portion protruding in a direction perpendicular to an axial direction of the coil body. A secondary coil of the coil body has a maximum outer diameter portion, and an inclined outer diameter portion arranged on two sides of the maximum outer diameter portion in the axial direction. The secondary coil includes a secondary electric wire that is wound obliquely around an outer periphery of a secondary spool such that reduced winding parts and enlarged winding parts are alternately superimposed on each other. The reduced winding part is wound with a winding diameter decreasing obliquely from one side to the other side in the axial direction, and the enlarged winding part is wound with a winding diameter increasing obliquely from the other side to the one side in the axial direction.

Abstract: An ignition coil for an internal combustion engine includes a primary coil formed by winding a primary winding a plurality of turns, a secondary coil formed by winding a secondary winding having a wire diameter of 30 to 100 ?m a plurality of turns, and a resin compact which is impregnated into between the lines of the primary winding and between the lines of the secondary winding and which seals the primary coil and the secondary coil. The resin compact includes a filler in a range of 65 weight percent to 80 weight percent in order to limit development of an electric tree in the resin compact, and the filler is composed of 60 weight percent or more spherical silica and 40 weight percent or less crushed silica.

Abstract: An ignition coil includes a coil body transversely arranged outside of a plug hole, and a plug connection portion protruding in a direction perpendicular to an axial direction of the coil body. A secondary coil of the coil body has a maximum outer diameter portion, and an inclined outer diameter portion arranged on two sides of the maximum outer diameter portion in the axial direction. The secondary coil includes a secondary electric wire that is wound obliquely around an outer periphery of a secondary spool such that reduced winding parts and enlarged winding parts are alternately superimposed on each other. The reduced winding part is wound with a winding diameter decreasing obliquely from one side to the other side in the axial direction, and the enlarged winding part is wound with a winding diameter increasing obliquely from the other side to the one side in the axial direction.

Abstract: An ignition coil includes a coil body, a plug connection portion protruding from the coil body, and a connector for electrically connecting the ignition coil to an outside. In the coil body, a primary coil is arranged on an inner peripheral side of a secondary coil, and a center core is arranged on an inner peripheral side of the primary coil. The secondary coil includes a secondary electric wire having thereon an insulating film, wound around an outer periphery of a resinous secondary spool. Furthermore, the connector is formed integrally with an end of the secondary spool in an axial direction.

Abstract: An ignition coil includes a primary coil and a secondary coil, a magnetic member through which a magnetic flux generated by the primary coil and the secondary coil passes, a resin case for accommodating therein the magnetic member, the primary coil and the secondary coil, and an insulating resin for filling the resin case. The magnetic member is formed by compression molding of a green compact material using iron-based powder including an insulating coating. In the ignition coil, the green compact material contains 50% by weight or more of the iron-based powder having a particle size about in a range of 150 ?m to 300 ?m. Alternatively, the green compact material has a content of a binder being 0.15% by weight or less.

Abstract: In a stick coil, there is disclosed an ignition coil for an internal combustion engine which can prevent a crack (a collar leak) from being generated due to a thermal stress. In this ignition coil, the structure is made such that a size (L) of a portion which is in parallel to an axial direction of a primary spool (121) in a projection portion (121b) is larger than a size (T) of a portion which is in parallel to an orthogonal direction to the axial direction of the primary spool (121). Accordingly, a frontal projected area of the projection portion (121b) as seen from a flowing direction of a resin becomes small, a resin flow is hard to get out of order at a time when the resin flows through a portion corresponding to the projection portion (121b) at the forming time, and a convoluted void and a weld are hard to be generated.

Abstract: An ignition coil includes a housing which contains a central core portion, an inner spool having a first winding, and an outer spool having a second winding. The inner spool extends outward of the central core portion. The outer spool extends outward of the inner spool. A locating member includes a locating rib adjacent to an upper portion of the central core portion. The locating rib is in a gap between the inner spool and the central core portion, and locates the inner spool and the central core portion relative to each other. Insulating resin injected into the housing provides insulation among parts in the housing. At least one of the inner spool and the locating member has a void-escape passage which connects the gap and an outside of the inner spool with each other, and which allows a void to escape from the injected insulating resin in the gap.

Abstract: An ignition coil includes a housing which contains a central core portion, an inner spool having a first winding, and an outer spool having a second winding. The inner spool extends outward of the central core portion. The outer spool extends outward of the inner spool. A locating member includes a locating rib adjacent to an upper portion of the central core portion. The locating rib is in a gap between the inner spool and the central core portion, and locates the inner spool and the central core portion relative to each other. Insulating resin injected into the housing provides insulation among parts in the housing. At least one of the inner spool and the locating member has a void-escape passage which connects the gap and an outside of the inner spool with each other, and which allows a void to escape from the injected insulating resin in the gap.

Abstract: In a stick coil, there is disclosed an ignition coil for an internal combustion engine which can prevent a crack (a collar leak) from being generated due to a thermal stress. In this ignition coil, the structure is made such that a size (L) of a portion which is in parallel to an axial direction of a primary spool (121) in a projection portion (121b) is larger than a size (T) of a portion which is in parallel to an orthogonal direction to the axial direction of the primary spool (121). Accordingly, a frontal projected area of the projection portion (121b) as seen from a flowing direction of a resin becomes small, a resin flow is hard to get out of order at a time when the resin flows through a portion corresponding to the projection portion (121b) at the forming time, and a convoluted void and a weld are hard to be generated.