Europaisches Patentamt European Patent Office © Publication number: 0 536 81 1 A2 Office europeen des brevets EUROPEAN PATENT APPLICATION © Application number: 92120484.8484.8 © int. Ci.5; F02P 7/02, H01 F 31/00 @ Date of filing: 24.04.89 © Priority: 26.04.88 JP 101227/88 Hitachi-shi, Ibaraki 319-12(JP) 01.08.88 JP 190644/88 Inventor: Kobayashi, Kazutoshi 4860-6 Mutsuno, Nakane @ Date of publication of application: Katsuta-shi, Ibaraki 312(JP) 14.04.93 Bulletin 93/15 Inventor: Sugiura, Noburu 1360-27, Kasahara-cho © Publication number of the earlier application in Mito-shi, Ibaraki 310(JP) accordance with Art.76 EPC: 0 339 892 Inventor: Kawakami, Kazuhiko 1360-26 Tarasaki © Designated Contracting States: Katsuta-shi, Ibaraki 312(JP) DE FR GB Inventor: Koshida, Ryoichi 63-6 Tabiko © Applicant: HITACHI, LTD. Katsuta-shi, Ibaraki 312(JP) 6, Kanda Surugadai 4-chome Chiyoda-ku, Tokyo 101(JP) © Representative: Molyneaux, Martyn William @ Inventor: Shimada, Junichi c/o Ladas & Parry, Altheimer Eck 2 4-22, Minamikouya-cho 3-chome W-8000 Munchen 2 (DE) © Ignition coil-incorporated distributor for internal combustion engines. © An ignition coil-incorporated distributor in which FIG. 8 an ignition coil is incorporated in a distributor hous- ing has a core for the ignition coil located in an enclosure member (75, 76; 74) retaining the core (71). A set screw (79) fastens the enclosure member to an inner surface of the housing (2). CM 00 CO 00 m Rank Xerox (UK) Business Services (3. 10/3.5x/3.0. 1) 1 EP 0 536 81 1 A2 2 Background of the Invention: wound around the cylindrical core through which a rotor shaft of the distributor passes, the ignition coil This invention relates to an ignition coil-incor- being mounted on the upper side of a bearing for porated distributor for internal combustion engines, supporting the rotor shaft. in which an ignition coil for internal combustion 5 In this distributor, the construction of the iron engines is incorporated in a distributor. core is very complicated. Further, since the ignition An example of an ignition coil-incorporated dis- coil is disposed at the upper side of the bearing for tributor for internal combustion engines is disclosed the rotor shaft, the size of the distributor increases in Japanese Patent Publication No. 60-18834/1985, in the direction of the longitudinal axis thereof by wherein the ignition coil-incorporated distributor io the height of the ignition coil. When the shaft is comprises a housing, a rotor shaft rotatably sup- connected directly to a cam shaft in an engine, the ported by the housing, a cap fitted to the housing, distance between the bearings for the shaft de- a distributor part including a rotor electrode moun- creases, so that the shaft shakes during the rota- ted on a rotor top end of the rotor shaft and a side tion thereof. This would cause interference of parts electrode mounted on the cap to face the rotor 75 secured to the shaft with other parts facing the electrode with a gap therebetween, an ignition coil parts and generation of an unstable output signal. secured to the housing, a signal rotor secured to When the distributor is disposed laterally in an the rotor shaft, a magnetic pickup for picking up engine, that is, the longitudinal axis of the distribu- signals and interrupting current flowing in a primary tor is disposed horizontal, the center of gravity coil of the ignition coil according to the signal to 20 thereof in the direction of the longitudinal axis cause a secondary coil of the ignition coil to induce thereof separates from the position in which the a high voltage, etc.. distributor is fixed to the engine. Therefore, the In this ignition coil-incorporated distributor, the distributor is readily vibrated, and the reliability of ignition coil is mounted on the housing at a position the strength thereof lowers. separated from the rotor shaft on one side a dis- 25 tance sufficient by means of screw passing through Summary of the Invention: a hole formed in a core of the ignition coil in a direction perpendicular to the axis of the rotor An object of the present invention is to provide shaft. an ignition coil-incorporated distributor for internal In the distributor, a portion of the distributor in 30 combustion engines, which is simple in construc- which the ignition coil is provided projects side- tion, small-sized, mechanically stable and capable ways to increase the dimensions of the distributor. of being easily assembled. Further, the weight of the ignition coil having a According to this invention there is provided an winding wound around an iron core thereof and ignition coil-incorporated distributor having a hous- provided at a side portion of the housing has a 35 ing fixed to an internal combustion engine, a shaft considerable percentage of a total weight of the inserted at its one end portion into said housing to distributor, so that the distributor becomes unstable be rotated synchronously with a crankshaft in said with respect to the longitudinal axis thereof, and internal combustion engine, a signal rotor mounted may give rise to troubles when it is mounted on a on said shaft, a rotation signal detector provided in vehicle. 40 said housing, opposed in a separated state to said Furthermore, the ignition coil is fixed by screw signal rotor, and adapted to generate a signal syn- means at right angles to the direction of the lon- chronous with the rotation of said signal rotor, and gitudinal axis of the distributor. Consequently, parts an ignition coil provided in said housing and includ- of the distributor are screwed in various directions. ing a core and primary and secondary winding This causes the distributor assembling operation to 45 around said magnetic path-forming core, charac- become complicated, and the assembling efficien- terised by an enclosure member retaining said cy to decrease. core, and a set screw fastening said enclosure Another example of the ignition coil-incorpo- member to the inner surface of said housing, rated distributor is disclosed in Japanese Patent whereby said ignition coil is fixed to the inner side Laid-Open No. 61-231708/1986, wherein an ignition 50 of said housing. coil comprises an iron core constructed of various The ignition coil is preferably incorporated into parts, that is, a cylindrical core axially elongated, a the housing by fixing the core thereof to the hous- pair of cruciform cores disposed on upper and ing by screw means in the direction in which the lower sides of the cylindrical core, respectively, rotor shaft of the distributor extends, in the same and having four (4) arm portions radially extending, 55 manner as other parts. and plate-like cores at the tips of the arm portions Therefore, by virtue of the present invention, of the cruciform cores to magnetically connect the the dimensions of the distributor as a whole de- upper and lower cruciform cores; and windings crease, and the distance between bearings for sup- 2 3 EP 0 536 81 1 A2 4 porting the shaft can be set long, whereby the rotatably supported by the housing 2, a signal rotor shaking of the shaft during the rotation thereof 3 secured to the shaft 1 and having a plurality of does not occur. The ignition coil is incorporated projections extending radially, the number of which into the housing by a sim pie assembling operation projections corresponds to the number of cylinders with the stability and strength of the distributor kept 5 of the engine (not shown), a signal pickup device 5 sufficiently high. for picking up a signal in corporation with the signal rotor 3 as a crank angle position signal which is Brief Description of the Drawings: inputted into a control unit (not shown) to generate an ignition timing signal employing the crank angle Fig. 1 is a longitudinally section view showing io position signal, etc. electric current flowing in a the construction of an embodiment of an ignition primary coil or winding of the ignition coil 7 being coil-incorporated distributor according to EP-A- interrupted according to the ignition timing signal to 0339892; induce a high voltage in a secondary coil or wind- Fig. 2 is a plan view showing the construction of ing of the ignition coil 7, that is, at an output the ignition coil-incorporated distributor of Fig. 1; is terminal of the ignition coil 7, a rotor head 4 moun- Fig. 3 is a perspective view showing the con- ted on the top of the shaft 1 , and a cap 6, fitted to struction of an iron core of an ignition coil of the the housing 2 so as to enclose the pickup device 5 ignition coil-incorporated distributor in Fig. 1; and ignition coil 7, and having a central electrode 9 Fig. 4 is a perspective view showing the con- positioned at the central portion of the rotor head 4 struction of winding in the ignition coil of the 20 and a side electrode 10 fixed thereto and posi- ignition coil-incorporated distributor in the em- tioned at one side of the rotor head 4 with a gas bodiment of Fig. 1 ; therebetween. Fig. 5 is a perspective view showing the con- The housing 2, as shown in Figs. 1 and 7, struction of the ignition coil in the embodiment includes a bottom portion 21 , a side wall portion 22 of Fig. 1; 25 upstanding from the periphery of the bottom por- Fig. 6 is a sectional view of the ignition coil tion 21, and a shaft support portion 23 projecting taken along a line VI-VI of Fig.