Abstract: An ignition coil for an internal combustion engine is mainly made up of a transformer part and a control circuit part and a connecting part, and the transformer part is made up of a iron core which forms an open magnetic path, magnets, a secondary spool, a secondary coil, a primary spool and a primary coil. By respectively setting the cross-sectional area SC of the iron core between 39 to 54 mm2, the ratio of the cross-sectional area SM of the magnets with the cross-sectional area SC of the iron core in the 0.7 to 1.4 range, the ratio of the axial direction length LC of the iron core with the winding width L of the primary and secondary coils in the 0.9 to 1.2 range, and the winding width L in the 50 to 90 mm range, the primary energy produced in the primary coil can be increased without increasing the external diameter A of the case.

Abstract: A stick-type ignition coil have a central core, a cylindrical member, primary spool, primary coil, secondary spool, secondary coil, outer core and a resin insulator. The two longitudinal end corners and faces of the core are covered by respective buffer members. The inner circumferential corners of the outer core is supported by ring members. Some of the members disposed radially inside and other members disposed radially outside of the inside members are held slidably to each other in the ignition coil. The spools are made of resin containing a rubber in excess of 5 weight percent and reinforcing materials. The resin insulator contains a flexible material.

Abstract: A stick-type ignition coil have a central core, a cylindrical member, primary spool, primary coil, secondary spool, secondary coil, outer core and a resin insulator. The two longitudinal end corners and faces of the core are covered by respective buffer members. The inner circumferential corners of the outer core is supported by ring members. Some of the members disposed radially inside and other members disposed radially outside of the inside members are held slidably to each other in the ignition coil. The spools are made of resin containing a rubber in excess of 5 weight percent and reinforcing materials. The resin insulator contains a flexible material.

Abstract: An ignition coil for an internal combustion engine is mainly made up of a transformer part and a control circuit part and a connecting part, and the transformer part is made up of a iron core which forms an open magnetic path, magnets, a secondary spool, a secondary coil, a primary spool and a primary coil. By respectively setting the cross-sectional area SC of the iron core between 39 to 54 mm2, the ratio of the cross-sectional area SM of the magnets with the cross-sectional area SC of the iron core in the 0.7 to 1.4 range, the ratio of the axial direction length LC of the iron core with the winding width L of the primary and secondary coils in the 0.9 to 1.2 range, and the winding width L in the 50 to 90 mm range, the primary energy produced in the primary coil can be increased without increasing the external diameter A of the case.

Abstract: An ignition coil for an internal combustion engine is mainly made up of a transformer part and a control circuit part and a connecting part, and the transformer part is made up of a iron core which forms an open magnetic path, magnets, a secondary spool, a secondary coil, a primary spool and a primary coil. By respectively setting the cross-sectional area SC of the iron core between 39 to 54 mm2, the ratio of the cross-sectional area SM of the magnets with the cross-sectional area SC of the iron core in the 0.7 to 1.4 range, the ratio of the axial direction length Lc of the iron core with the winding width L of the primary and secondary coils in the 0.9 to 1.2 range, and the winding width L in the 50 to 90 mm range, the primary energy produced in the primary coil can be increased without increasing the external diameter A of the case.

Abstract: An electromagnetic coil which may be employed as an ignition coil for an internal combustion engine is disclosed. The electromagnetic coil includes a lower voltage winding portion and a higher voltage winding portion. The lower voltage winding portion is wound around a spool and includes a plurality of winding layers overlapped with each other and inclined at a given angle to the length of the spool. Each of the winding layers includes a collection of turns made up of a leading portion of wire. The higher voltage winding portion is wound around the spool adjacent the lower voltage winding portion and includes a plurality of winding layers overlapped with each other and inclined at a given angle to the length of the spool. Each of the winding layers includes a collection of turns made up of a trailing portion of the wire.

Abstract: A high voltage post terminal is accurately located within a support aperture during manufacturing processes by at least one inwardly directed projection to avoid assembly problems caused by sizing the entire aperture itself to locate the terminal with sufficient accuracy. By thus improving the concentricity of the high voltage coil components it is possible to achieve more reliable insulation between components at even relatively small-sized coils used for individual engine plug holes. An especially advantageous range of critical parameters has been discovered as achievable by using this more reliable manufacturing process.

Abstract: A stick-type ignition coil have a central core, a cylindrical member, primary spool, primary coil, secondary spool, secondary coil, outer core and a resin insulator. The two longitudinal end corners and faces of the core are covered by respective buffer members. The inner circumferential corners of the outer core is supported by ring members. Some of the members disposed radially inside and other members disposed radially outside of the inside members are held slidably to each other in the ignition coil. The spools are made of resin containing a rubber in excess of 5 weight percent and reinforcing materials. The resin insulator contains a flexible material.

Abstract: An ignition coil has a coil case made of an insulating resin, including a head portion, a cylinder portion accommodating a primary coil, and a secondary coil and a high-voltage tower portion for fitting with a spark plug. At least one of those three portions is separately molded and then the portions are assembled to form the coil case. The longitudinal length of each of the three portions is less than a forming flow length of the insulating resin, thereby preventing inferior molding. Further, the structure of each molding die is simpler than that of the coil case for an integral molding. Therefore, the coil case of the ignition coil can be molded readily without molding defects, even when the coil case is elongated, formed thinner, and/or formed with an undercut portion.

Abstract: An electromagnetic coil which may be employed as an ignition coil for an internal combustion engine is disclosed. The electromagnetic coil includes a lower voltage winding portion and a higher voltage winding portion. The lower voltage winding portion is wound around a spool and includes a plurality of winding layers overlapped with each other and inclined at a given angle to the length of the spool. Each of the winding layers includes a collection of turns made up of a leading portion of wire. The higher voltage winding portion is wound around the spool adjacent the lower voltage winding portion and includes a plurality of winding layers overlapped with each other and inclined at a given angle to the length of the spool. Each of the winding layers includes a collection of turns made up of a trailing portion of the wire.

Abstract: A traverse shaft section 609 shifts in response to the rotation of a bobbin rotating section 604 with a predetermined winding pitch P1 equivalent to two to 10 times the diameter of a wire rod 520. With this shift movement of traverse shift section 609, wire rod 520 extracted from a winding nozzle section 610 shifting together with traverse shaft section 609 is wound spirally along a slant surface 530 formed by a first winding section 541 at the winding pitch P1 equivalent to two to 10 times the diameter of a wire rod 520. As a result, an advancing-side wire rod 520a and a reversing-side wire rod 520b cross over each other at opposing inclinations. Hence, it becomes possible to prevent the reversing-side wire rod 520b, when wound on the advancing-side wire rod 520a, from pulling and dislocating the advancing-side wire rod 520a from its regular winding position, thereby eliminating undesirable winding collapse.

Abstract: A piling machine includes a table with a plurality of step-shelves, a slider and a stopper. One of a plurality of iron strips is placed in a prescribed order on each of the step-shelves, caught by the slider one by one, and piled together as the slider proceeds. When the slider is stopped by the stopper, all the strips are piled up to form a strip assembly. The stopper has a curved front surface to neatly hold the strip assembly, thereby easily forming the strip assembly into a desired shape.

Abstract: To provide an ignition coil for an internal combustion engine which improves high-voltage sealing performance and moreover reduces housing outer diameter, an ignition coil for an internal combustion engine is made up of a transformer portion of cylindrical configuration housed within a housing chamber of a case, a control-circuit portion which is positioned on one end portion of this transformer portion and causes primary current of the transformer portion to be intermittent, and a connecting portion which is positioned on another end portion of the transformer portion and supplies secondary voltage of the transformer portion to a spark plug. The interior of the housing chamber is filled with insulating oil which has a flash point of 180.degree. C. or more, a total acid number of oxidation stability of 0.6 mgKOH/g or less, a pour point of -20.degree. C. or less with no cloudiness occurring before that temperature is reached, and a kinematic viscosity of not less than 20 cSt and not more than 180 cSt at 40.

Abstract: An ignition coil for an internal combustion engine, having a seal between the ignition coil and a plug hole of the engine. An air passage is provided only on a head portion and a pipe portion of the ignition coil to permit air to pass. Pressure change in the plug hole can be equalized with the atmosphere through the air passage. Therefore, it becomes easy to make the seal and to attach the seal to the ignition coil because the seal does not have any air passage.

Abstract: An ignition coil is composed of a transformer, an igniter, a housing accommodating them and a fixing portion disposed at a place within easy access from an opening of the housing to fix the igniter, a terminal pin disposed at a place of the housing within easy access from the opening and connected to the control circuit and a connector pin fixed to the housing and connected to the terminal pin. The igniter and fixing portion have a member for adjusting relative location therebetween to connect the connector pin and terminal pin without stress.

Abstract: A traverse shaft section 609 shifts in response to the rotation of a bobbin rotating section 604 with a predetermined winding pitch P1 equivalent to two to 10 times the diameter of a wire rod 520. With this shift movement of traverse shift section 609, wire rod 520 extracted from a winding nozzle section 610 shifting together with traverse shaft section 609 is wound spirally along a slant surface 530 formed by a first winding section 541 at the winding pitch P1 equivalent to two to 10 times the diameter of a wire rod 520. As a result, an advancing-side wire rod 520a and a reversing-side wire rod 520b cross over each other at opposing inclinations. Hence, it becomes possible to prevent the reversing-side wire rod 520b, when wound on the advancing-side wire rod 520a, from pulling and dislocating the advancing-side wire rod 520a from its regular winding position, thereby eliminating undesirable winding collapse.

Abstract: An ignition coil for an internal combustion engine, includes a housing to be mounted in on the internal combustion engine and a coil portion dipped in an insulating oil filled in the housing. The housing is molded of a material containing any selected from the group consisting of polyphenylene sulfide, polyphenylene oxide, polyarylate, polyether imide and a liquid crystal polymer, and a reinforcing filler is added to the material.