Abstract: An ignition coil for an internal combustion engine is provided which includes a case, a connector, a resinous member, and a retainer. The case is equipped with an opening portion and has component parts mounted therein. The connector is electrically connected to an external device. The resinous member is disposed in the case. The retainer firmly hold an external connecting member joined to the connector. The retainer is mechanically discrete from the case and secured to an attachment wall of the case. The attachment wall is defined by at least one of a wall of the case which constitutes the opening portion and a wall secured to the opening portion. The retainer has a portion embedded in the resinous member. This structure minimizes fretting wear between terminals of the connector and the external connecting member such as a wire harness.

Abstract: An ignition coil unit is attached to an engine body. The engine body includes a cylinder head having a plug hole and a head cover that covers the cylinder head by including an opening hole facing the plug hole. The ignition coil unit includes a coil unit that generates a high voltage and a cylindrical coupling unit that connects the coil unit with a spark plug. The coupling unit includes a flexible sealing section fitting to an outer peripheral surface of the high tension tower and a harder joint fitting to a tip of the sealing section. The sealing section includes an adhesion portion to tightly contact the head cover and a neck portion at least between the adhesion portion and the joint in a Z-axis direction. The neck portion is formed by partially constricting an outer peripheral surface of the sealing section radially inside.

Abstract: An ignition coil for internal combustion engines is provided which includes a primary coil, a secondary coil, a case, a high-voltage terminal, a resistor, and a filled resin. The case has a case body and a high-voltage terminal extending downward from the case body. The high-voltage terminal is press-fit in the high-voltage tower to close the inside thereof. The resistor is fit in the high-voltage terminal. The high-voltage terminal includes a pressed wall and a non-pressed wall. The pressed wall is pressed against the high-voltage tower. The non-pressed wall is not pressed against the high-voltage tower. The resistor is fit in the non-pressed wall. This structure minimizes pressure exerted on the resistor and the high-voltage tower to secure a desired degree of durability of the resistor and the high-voltage tower.

Abstract: An ignition coil for internal combustion engines is provided which includes a primary coil, a secondary coil, a case, a closing member, and a filled resin. The case includes a case body and a high-voltage tower. The closing member is press fit in the high-voltage tower to close the inside of the high-voltage tower. The closing member includes a resinous cylinder, a high-voltage terminal firmly attached to the resinous cylinder, and a resistor fit in the high-voltage terminal. The high-voltage terminal is of a hollow cylindrical shape with a bottom and an upper opening. The closing member has an outer peripheral surface of the resinous cylinder press-fit in the high-voltage tower. This structure minimizes pressure exerted on the resistor and the high-voltage tower to secure a desired degree of durability of the resistor and the high-voltage tower.

Abstract: An ignition coil is provided with a primary coil, a secondary coil, a center core, and an outer core. The primary coil, secondary coil, the center core, and the outer core are accommodated inside a case, the inside of the case is filled with a resin filler having electrical insulating properties. The case has an opening member which opens to an upper-side of a vertical direction, a side wall section formed by the opening member, and a bottom member covering a lower-side of the side wall section. A circular cover member, formed on the opening member, provided with a through opening which passes through the inner-side of the opening member in the vertical direction.

Abstract: An ignition coil unit is attached to an engine body. The engine body includes a cylinder head having a plug hole and a head cover that covers the cylinder head by including an opening hole facing the plug hole. The ignition coil unit includes a coil unit that generates a high voltage and a cylindrical coupling unit that connects the coil unit with a spark plug. The coupling unit includes a flexible sealing section fitting to an outer peripheral surface of the high tension tower and a harder joint fitting to a tip of the sealing section. The sealing section includes an adhesion portion to tightly contact the head cover and a neck portion at least between the adhesion portion and the joint in a Z-axis direction. The neck portion is formed by partially constricting an outer peripheral surface of the sealing section radially inside.

Abstract: An ignition coil for an internal combustion engine includes a coil main body portion, a connecting portion, and a conducting member. A convex surface forming portion, which is a portion constituting an inner peripheral convex surface, is disposed in the connecting portion. The convex surface forming portion has an outer peripheral concave surface. The connecting portion has a boundary portion which is a boundary between the convex surface forming portion and other portions in the axial direction. In the convex surface forming portion, at least a part of a region where the outer peripheral concave surface is formed has a portion having an area, in a cross-section orthogonal to the axial direction, equal to or smaller than that of the boundary portion. A thickness of the convex surface forming portion is equal to or thicker than that of the boundary portion.

Abstract: An ignition coil for internal combustion engines is provided which includes a primary coil, a secondary coil, a case, a high-voltage terminal, a resistor, and a filled resin. The case has a case body and a high-voltage terminal extending downward from the case body. The high-voltage terminal is press-fit in the high-voltage tower to close the inside thereof. The resistor is fit in the high-voltage terminal. The high-voltage terminal includes a pressed wall and a non-pressed wall. The pressed wall is pressed against the high-voltage tower. The non-pressed wall is not pressed against the high-voltage tower. The resistor is fit in the non-pressed wall. This structure minimizes pressure exerted on the resistor and the high-voltage tower to secure a desired degree of durability of the resistor and the high-voltage tower.

Abstract: An ignition coil for internal combustion engines is provided which includes a primary coil, a secondary coil, a case, a closing member, and a filled resin. The case includes a case body and a high-voltage tower. The closing member is press fit in the high -voltage tower to close the inside of the high-voltage tower. The closing member includes a resinous cylinder, a high-voltage terminal firmly attached to the resinous cylinder, and a resistor fit in the high-voltage terminal. The high-voltage terminal is of a hollow cylindrical shape with a bottom and an upper opening. The closing member has an outer peripheral surface of the resinous cylinder press-fit in the high-voltage tower. This structure minimizes pressure exerted on the resistor and the high-voltage tower to secure a desired degree of durability of the resistor and the high-voltage tower.

Abstract: An ignition coil for an internal combustion engine is provided which includes a case, a connector, a resinous member, and a retainer. The case is equipped with an opening portion and has component parts mounted therein. The connector is electrically connected to an external device. The resinous member is disposed in the case. The retainer firmly hold an external connecting member joined to the connector. The retainer is mechanically discrete from the case and secured to an attachment wall of the case. The attachment wall is defined by at least one of a wall of the case which constitutes the opening portion and a wall secured to the opening portion. The retainer has a portion embedded in the resinous member. This structure minimizes fretting wear between terminals of the connector and the external connecting member such as a wire harness.

Abstract: An ignition coil for an internal combustion engine includes an annular elastic seal which is tightly attached to a high-voltage tower and a plug installed in the high-voltage tower to be conductible with a spark plug. The elastic seal hermetically seals a gap between the high-voltage tower and the plug and also functions as a buffer to absorb stress, as exerted from the plug on a case of the ignition coil. This enables the case to be reduced in size as a whole without having to partially increase the wall thickness of the case to ensure a required degree of stiffness of the case and also results in improved degree of hermetic sealing between the plug and the high-voltage tower.

Abstract: An ignition coil for an internal combustion engine includes a coil main body portion, a connecting portion, and a conducting member. A convex surface forming portion, which is a portion constituting an inner peripheral convex surface, is disposed in the connecting portion. The convex surface forming portion has an outer peripheral concave surface. The connecting portion has a boundary portion which is a boundary between the convex surface forming portion and other portions in the axial direction. In the convex surface forming portion, at least a part of a region where the outer peripheral concave surface is formed has a portion having an area, in a cross-section orthogonal to the axial direction, equal to or smaller than that of the boundary portion. A thickness of the convex surface forming portion is equal to or thicker than that of the boundary portion.

Abstract: An ignition coil for internal combustion engines is provided which includes magnetically coupled primary and secondary coils, a case, a high-voltage tower, a resistor, and resin packed in the case. The case has the primary coil and the secondary coil disposed therein. The high-voltage tower is attached to a tower mount formed on a front end of the case. The resistor is embedded in the high-voltage tower with a front and a base end surfaces thereof exposed from the high-voltage tower. The resin is packed in the case to seal the primary coil and the secondary coil. This structure enhances the productivity of an assembly of the high-voltage tower and the resistor.

Abstract: An ignition coil for internal combustion engines is provided which includes a primary and a secondary coils magnetically coupled with each other, a case, a resistor, and a resinous filler. The case includes a case body in which the primary and secondary coils are disposed and a tubular high-voltage tower extending from the case body toward a head of the ignition coil. The resistor 3 is press-fitted into the high-voltage tower and electrically connected to the secondary coil. The resinous filler is packed in the case body to hermetically seal the primary coil and the secondary coil. The resistor includes a resinous coating which covers an outer circumference of the resistor and is press-fit in the high-voltage tower through the resinous coating. This facilitates hermetically sealing a gap between the resistor body and the case and ensures the stability of the sealing.

Abstract: An ignition coil is provided with a primary coil, a secondary coil, a center core, and an outer core. The primary coil, secondary coil, the center core, and the outer core are accommodated inside a case, the inside of the case is filled with a resin filler having electrical insulating properties. The case has an opening member which opens to an upper-side of a vertical direction, a side wall section formed by the opening member, and a bottom member covering a lower-side of the side wall section. A circular cover member, formed on the opening member, provided with a through opening which passes through the inner-side of the opening member in the vertical direction.

Abstract: An ignition coil for internal combustion engines is provided which includes magnetically coupled primary and secondary coils, a case, a high-voltage tower, a resistor, and resin packed in the case. The case has the primary coil and the secondary coil disposed therein. The high-voltage tower is attached to a tower mount formed on a front end of the case. The resistor is embedded in the high-voltage tower with a front and a base end surfaces thereof exposed from the high-voltage tower. The resin is packed in the case to seal the primary coil and the secondary coil. This structure enhances the productivity of an assembly of the high-voltage tower and the resistor.

Abstract: An ignition coil for internal combustion engines is provided which includes a primary and a secondary coils magnetically coupled with each other, a case, a resistor, and a resinous filler. The case includes a case body in which the primary and secondary coils are disposed and a tubular high-voltage tower extending from the case body toward a head of the ignition coil. The resistor 3 is press-fitted into the high-voltage tower and electrically connected to the secondary coil. The resinous filler is packed in the case body to hermetically seal the primary coil and the secondary coil. The resistor includes a resinous coating which covers an outer circumference of the resistor and is press-fit in the high-voltage tower through the resinous coating. This facilitates hermetically sealing a gap between the resistor body and the case and ensures the stability of the sealing.

Abstract: An ignition coil for an, internal combustion engine includes an annular elastic seal which is tightly attached to a high-voltage tower and a plug installed in the high-voltage tower to be conductible with a spark plug. The elastic seal hermetically seals a gap between the high-voltage tower and the plug and also functions as a buffer to absorb stress, as exerted from the plug on a case of the ignition coil. This enables the case to be reduced in size as a whole without having to partially increase the wall thickness of the case to ensure a required degree of stiffness of the case and also results in improved degree of hermetic sealing between the plug and the high-voltage tower.

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.