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 1 according to the invention is an ignition coil having a case 2 and a coil portion 7 accommodated in the case. The case comprises a base resin whose dielectric breakdown voltage exceeds that of polyphenylene sulfide and whose spiral flow length exceeds that of polybutyrene terephthalate. As the base resin has a high fluidity, there is only a limited risk that a defect such as a weld line is caused when molding a thin case. In addition, while the thickness of the case and the electrical insulation properties are in proportion to each other, the case comprising the base resin can ensure sufficient electrical insulation properties even if the case is formed thin.

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: A resin composite material according to the present invention contains a thermoplastic resin composition containing a polyphenylene oxide, a layered clay mineral dispersed in the thermoplastic resin composition and organized with an organizing agent, and a polar compound dispersed in the thermoplastic resin composition and chemically bonded to the layered clay mineral. The layered clay mineral is satisfactorily uniformly dispersed in the thermoplastic resin composition even after kneading under high temperature conditions. The resin composite material has adequately enhanced characteristics of mechanical strength, durability, and so on.

Abstract: A gate to mold a primary spool of an ignition coil device is placed at a part which does not oppose a main part of a secondary coil in the primary spool, that is, at a part other than a coil winding portion. It is preferred to use a resin having a high dielectric withstanding voltage and a high flowability, such as polybutylene terephthalate (PBT) or polyethylene terephthalate (PET), polyphenylene oxide (PPO)/polystyrene (PS), or liquid crystal polymer. By arranging the gate except at the winding portion, resin deterioration or cracks occur only at a part which does not oppose the secondary coil, that is, at a part where a high voltage from the secondary coil is relatively low. An adequate dielectric withstanding voltage is ensured without winding an insulation tape around the winding portion.

Abstract: In a stick-type ignition coil device for engines, a primary spool is disposed outside a secondary coil. The primary spool is made of PBT (polybuthylene telephthalate) having a low melting viscosity and a high flowability as a resin base material. The resin base material is admixed with an olefin rubber in 5 wt. %, glass fibers in 12.5 wt. % and silica in 12.5 wt. %. A primary coil 24 comprises a wire body coated with PET (polyethylene telephthalate), silicone or wax as a separating member, and is wound around the primary spool. The growth of trees in the primary spool 23 restricted even when electrical discharges occur between a secondary coil and the primary coil and the primary spool is eroded by the electrical discharges, because silica is added in the primary spool.

Abstract: A stick-type ignition coil to be directly connected to a spark plug via a spring. A high tension case containing a high tension terminal and a spring is integrally connected to the bottom end of a high tension generating portion of the ignition coil. The high tension terminal and the spring are separately supported in the high tension case before the spark plug is connected to the ignition coil. When the spark plug is connected, the spring is compressed and contacts the high tension terminal, thereby making electrical contact between the ignition coil and the spark plug. Since the spring and the high tension terminal are supported on separate positions in the case, the spring can be properly compressed without being distorted or jammed between the high tension terminal and the case.

Abstract: An ignition coil that can be easily assembled, that assures co-axial alignment of a primary coil, a secondary coil and a center core part, and that generates desired high voltage. A core body is formed to have an outer diameter larger than that of a permanent magnet so that the permanent magnet will not protrude out of the outer peripheral face of the core body. Accordingly, when the center core part is inserted into a secondary spool, the center core part is not caught by the secondary spool and may be readily inserted and assembled therewith. Also, because no bulge is created at the center core part, it is possible to prevent the center core part from tilting within the secondary spool and to readily assure the co-axial alignment of the primary spool, the secondary spool and the center core part. Thus, voltage generated by the secondary coil is prevented from dropping, and high voltage may be applied to the ignition plug.