Abstract: An ignition coil includes a coil main body portion, a conductive member, and a protective portion. The coil main body portion generates a high voltage. The conductive member electrically connects the coil main body portion and a terminal metal fitting of a spark plug. The conductive member is arranged inside the protective portion. The protective portion has an electrically insulating property. The conductive member includes an elastic portion that elastically deforms in a longitudinal direction of the conductive member, and a conductive terminal that is arranged on a distal end side of the elastic portion. The conductive terminal has a distal end surface that includes a concave surface or a convex surface that abuts on the terminal metal fitting of the spark plug. A contact portion between the concave surface or the convex surface and the terminal metal fitting of the spark plug has an annular shape.

Abstract: An ignition coil includes a coil main body portion, a conductive member, and a protective portion. The coil main body portion generates a high voltage. The conductive member electrically connects the coil main body portion and a terminal metal fitting of a spark plug. The conductive member is arranged inside the protective portion. The protective portion has an electrically insulating property. The conductive member includes an elastic portion that elastically deforms in a longitudinal direction of the conductive member, and a conductive terminal that is arranged on a distal end side of the elastic portion. The conductive terminal has a distal end surface that includes a concave surface or a convex surface that abuts on the terminal metal fitting of the spark plug. A contact portion between the concave surface or the convex surface and the terminal metal fitting of the spark plug has an annular shape.

Abstract: An ignition coil is disclosed. The ignition coil includes an insulative material, a body, and a head coupled to the body. A portion of the insulative material is included in the body, and a portion of the insulative material is included in the head. The head includes a casing, a flange for coupling to an engine case, and a connector adapted to be connected to an external device. The head also includes a conducting terminal with a connector pin, an exposed contact, and a connecting part. The connector pin is coupled to the connector, the exposed contact is coupled to the casing or the flange, and the connecting part couples the exposed contact and the connector pin. A portion of the connecting part is embedded in the insulative material, and wherein a remaining portion is embedded in the casing. A method of manufacturing the ignition coil is also disclosed.

Abstract: An ignition coil is disclosed. The ignition coil includes an insulative material, a body, and a head coupled to the body. A portion of the insulative material is included in the body, and a portion of the insulative material is included in the head. The head includes a casing, a flange for coupling to an engine case, and a connector adapted to be connected to an external device. The head also includes a conducting terminal with a connector pin, an exposed contact, and a connecting part. The connector pin is coupled to the connector, the exposed contact is coupled to the casing or the flange, and the connecting part couples the exposed contact and the connector pin. A portion of the connecting part is embedded in the insulative material, and wherein a remaining portion is embedded in the casing. A method of manufacturing the ignition coil is also disclosed.

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 has an outer coil unit, an inner coil unit, a coil case in which the outer and inner coil units are housed and a tower case accommodating lower parts of outer and inner spools. The outer spool is made of resin material whose bonding strength to resin insulating material, with which the tower case is filled, is weak. An axial leading end of the outer spool is positioned axially away from a reference position by a distance equal to or shorter than 60% of a reference length or by a distance equal to or longer than 90% of the reference length. With this ignition coil, cracks are suppressed on the resin insulating material opposed to the axial leading end of the outer spool otherwise caused by thermal stress.

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: In an ignition coil assembly, a plurality of ignition coils is arranged to be electrically connected to spark plugs received in plug holes of an engine. A base cover includes a plurality of receiving through holes, which are arranged at corresponding positions that correspond to positions of the plug holes, respectively. A top cover covers a top surface of the base cover and secures each ignition coil through engagement with the head of each ignition coil. Fastening bolts temporarily fasten the top cover and the base cover in a manner that allows sliding adjustment of a securing position of each ignition coil, which is loosely received in a corresponding one of the base cover through holes, in an imaginary plane that is perpendicular to an axis of each ignition coil.

Abstract: In an ignition coil assembly, a plurality of ignition coils is arranged to be electrically connected to spark plugs received in plug holes of an engine. A base cover includes a plurality of receiving through holes, which are arranged at corresponding positions that correspond to positions of the plug holes, respectively. A top cover covers a top surface of the base cover and secures each ignition coil through engagement with the head of each ignition coil. Fastening bolts temporarily fasten the top cover and the base cover in a manner that allows sliding adjustment of a securing position of each ignition coil, which is loosely received in a corresponding one of the base cover through holes, in an imaginary plane that is perpendicular to an axis of each ignition coil.

Abstract: In an ignition coil assembly, a plurality of ignition coils is arranged to be electrically connected to spark plugs received in plug holes of an engine. A base cover supports the ignition coils at corresponding positions, which correspond to positions of the plug holes, respectively. A top cover covers a top surface of the base cover. Connecting bolts connects between the top cover and the base cover. Fastening bolts secures only the base cover to the engine.

Abstract: In an ignition coil assembly, a plurality of ignition coils is arranged to be electrically connected to spark plugs received in plug holes of an engine. A base cover supports the ignition coils at corresponding positions, which correspond to positions of the plug holes, respectively. A top cover covers a top surface of the base cover. Connecting bolts connects between the top cover and the base cover. Fastening bolts secures only the base cover to the engine.

Abstract: In an ignition coil having an outer coil unit, an inner coil unit, a coil case in which the outer and inner coil units are housed and a tower case accommodating lower parts of outer and inner spools, the outer spool is made of resin material whose bonding strength to resin insulating material, with which the tower case is filled, is weak and an axial leading end of the outer spool is positioned axially away from a reference position by a distance equal to or shorter than 60% of a reference length or by a distance equal to or longer than 90% of the reference length. With this ignition coil, cracks hardly occur on the resin insulating material opposed to the axial leading end of the outer spool by thermal stress.

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.