An ignition coil includes a center core, a first core member, and a second core member. The first core member includes a first core-facing portion facing a front core surface of the center core and a first core side portion extending rearward from the first core-facing portion. The second core member includes a second core-facing portion facing a rear core surface of the center core and a second core side portion extending frontward from the second core-facing portion. The first core-facing portion has an end surface contacting a portion of the second core side portion to create a first contact region. Similarly, the second core-facing portion has an end surface contacting a portion of the first core side portion to create a second contact region. The first and second contact regions are shaped to approach frontward close to the first core side portion. This structure enhances productivity of the ignition coil.

An ignition coil includes a primary coil, a secondary coil, a center core, a magnet body and an outer peripheral core. The outer peripheral core is provided with a first opposite side, a second opposite side and a coupling side, the first opposite side facing the magnet body from an opposite side of the center core, the second opposite side facing the center core from the opposite side of the magnet body, the coupling side coupling the first opposite side with the second opposite side. The center core has a magnet side flange portion disposed at an end portion in a magnet body side, protruding in a protrusion direction. A thick portion is formed at both of a part of the first opposite side and a part of the coupling side, and a thickness of the thick portion being larger than a minimum thickness of the second opposite side.

An ignition coil for an internal combustion engine includes a primary bobbin including a winding cylinder part and a connection part between the winding cylinder part and a connector part, a primary coil including a primary main coil and a primary sub coil, and a secondary coil. When one of the primary main coil and the primary sub coil that includes an innermost coil part around the winding cylinder part is defined as a firstly-wound coil and the other is defined as a secondly-wound coil, firstly-wound ends, which are ends of the firstly-wound coil, and secondly-wound ends, which are ends of the secondly-wound coil, are attached to the connection part, and a shortest distance from a central axis of the winding cylinder part to each of the firstly-wound ends is smaller than a shortest distance from the central axis of the winding cylinder part to each of the secondly-wound ends.

An ignition coil includes a primary coil and a secondary coil magnetically coupled from each other; a core cover disposed around the primary coil and the secondary coil; and an outer peripheral core supported by the core cover. The core cover includes a pair of support portions that support the outer peripheral core; and at least one of the pair of support portions includes a flexible portion that elastically presses the outer peripheral core, the flexible portion having flexibility in an arrangement direction separating the pair of support portions.

An ignition coil for an internal combustion engine is provided. The ignition coil includes: a primary coil and a secondary coil magnetically coupled to each other; a second spool which the secondary coil is wound around; and a connection terminal connected to a high voltage side of the secondary coil and supported by a terminal support portion provided at the second spool. The terminal support portion includes an insertion hole portion allowing the connection terminal to be inserted in an insertion direction as a coil radial direction. The connection terminal includes a protrusion protruding outside the connection terminal in a direction orthogonally crossing the insertion direction. The protrusion is engaged to the insertion hole portion from inward in the coil radial direction.

An ignition apparatus for an internal combustion engine includes: a spark plug; a first ignition coil and a second ignition coil; a battery; a booster circuit that boosts a voltage supplied from the battery; a power transistor that conducts and interrupts a primary current flowing to a primary coil included in the first ignition coil; a MOSFET that applies and interrupts the voltage boosted by the booster circuit to a primary coil included in the second ignition coil; and an ECU that starts electric discharge by the spark plug by controlling the power transistor, and repeatedly applies and interrupts the voltage boosted by the booster circuit by the MOSFET so that the electric discharge that is started is maintained.

An internal combustion engine ignition device comprises: a center core; a primary coil wound on the outside of the center core; a secondary coil wound on the outside of the primary coil; a permanent magnet which abuts against one end of the center core and is magnetized in the inverse direction to the direction of a magnetic flux produced by the energization of the primary coil; a side core which is disposed on the outside of the secondary coil with one end abutted against the permanent magnet and the other end abutted against the center core, the side core cooperating with the permanent magnet to form a closed magnetic path; and a heat-resistant and elastic resin covering the side core with an opening at an outer peripheral side. Heat dissipation from the side core to a housing is improved without adversely affecting the dielectric strength voltage of the secondary coil.

The present invention provides an ignition coil which can be reduced in weight and cost while retaining the performance of conventional ignition coils. The objective of the present invention is to provide an ignition coil which can be manufactured using conventional processes, such that costs due to process switching are not incurred. The ignition coil is characterized by comprising: a pipe-shaped spool; and a wire wound on the outer circumference of the spool, wherein the wire is formed extending in one direction, and the central portion of a cross-section perpendicular to the direction of extension is formed of aluminum, while the outer surface of the cross-section is formed of copper.

An ignition device includes a case having an opening and a bottom wall, a coil bobbin arranged in the case having a through hole, a first end and a second end, an ignition coil wound around the coil bobbin, a core made of magnetic material and projecting from the opening and from the bottom wall, and extending through the coil bobbin, a retainer having a ring portion and multiple leg portions extending from the ring, and a filling resin in the case. The core extends through the ring portion and the leg portions extend in between an inner surface of the coil bobbin and an outer peripheral surface of the core toward the bottom wall, and the case is filled with the filling resin in a manner that at least a part of the ring portion is not covered by the resin.

An ignition coil for an internal combustion engine includes a primary bobbin including a winding cylinder part and a connection part between the winding cylinder part and a connector part, a primary coil including a primary main coil and a primary sub coil, and a secondary coil. When one of the primary main coil and the primary sub coil that includes an innermost coil part around the winding cylinder part is defined as a firstly-wound coil and the other is defined as a secondly-wound coil, firstly-wound ends, which are ends of the firstly-wound coil, and secondly-wound ends, which are ends of the secondly-wound coil, are attached to the connection part, and a shortest distance from a central axis of the winding cylinder part to each of the firstly-wound ends is smaller than a shortest distance from the central axis of the winding cylinder part to each of the secondly-wound ends.