Патент USA US2412690код для вставки
2,412,690 Patented Dec. 17, 1946 UNirED STATES PATE T oFFlcE 2,412,690 ’ « IGNITION APPARATUS FUR INTERNAL COMBUSTION ENGINES Walter Ochsenbeìn, Bern, Switzerland, assignor to Hasler A. G. Werke für Telephonie und Präzisionsmechanik, Bern, Switzerland Application June 12, 1943, Serial No. 490,706 In Switzerland February 2, 1942 2 Claims. (Cl. 12S-148) 1 The present invention relates to improvements in ignition apparatus for internal combustion en gines and more particularly to an ignition system for generating several directly consecutive sparks „ at the same spark plug within the same ignition period. ‘It is known that in the case of weak combusti' ' ble mixtures an increase of the engine power can be obtained by generating on each spark plug , Z . to the remaining contact’pieces of the group are generated with open interrupter. ` The accompanying drawing shows a diagram matic view of the ignition circuits of one of Vari ous possible embodiments of the ignition appa ratus according to this invention. It illustrates one half of a double magneto ignition system of ' a twelve-cylinder internal combustion engine. In the figure the reference I designates the pri two or more directly consecutive sparks during 10 mary Winding, 2 the interrupter, 3 the blow-out condenser, 4 the secondary winding, 5 the distrib one and the same ignitionperiod in the cylinder. utor, 6 the ñrst contact pieces of groups of two at A number of means have already been proposed a time and 8 the remaining contact pieces of each For instance, such a number of igni therefor. group. All these contact pieces 6 and ß are circu tion apparatus can be used as sparks must be larly disposed within contacting range of the generated per ignition order on each spark plug, >rotatable distributor arm 5’ and each group of so that each apparatus generates during an igni two contiguous contact pieces 6 and 8 is con tion periodV a single spark on one and the same nected wth a coordinate spark plug 1. When the spark plug. However, this proposition is not distributor arm- 5’ passes over the contact piece economical due to the high Weight, the usually 6 of a group the ignition current controlled by the existing diiiiculties for driving and the high costs. interrupter 2 flows as current impulse to the co There is a further possibility consisting, for ex ordinate spark plug ‘l and while the interrupter ample, in connecting several resistances into the is open, that is in the same ignition period, a fur primary circuit of an ignition system. By suc ther current impulse ñows through the same cessively short circuiting these resistances the magnetic iiux will be varied, whereon depends the 25 spark plug 1, as soon as the distributorV arm 5’ passes over the contact piece 8 of the same group. induction of the ignition voltage. An apparatus For the other half of the double magneto ignition of this disposition requires, compared with an or system a second distributor, 5 is provided with a. dinary ignition device, high electric power and is, rotatable arm which works in the same manner. therefore, excessively heavy and voluminous. Already known are also the apparatus for mul tiple ignition, wherein the ignition points of dif ferent circuits on one and the same spark plug can be adjusted independently of one another, so that forthwith, instead of a simultaneous igni tion, the ignition points adjusted may occur at intervals. The apparatus for multiple ignition will thereby, however, no more fully accomplish its original purpose, namely to secure a reliable ignition. It is an objectof the present invention to pro vide a plurality of contact pieces circularly dis posed within contacting range of a rotatable dis tributor and being spaced from one another, whereby at least two contact pieces at a time are exclusively connected to a spark plug, so that ac cordingly at each spark plug at least two sparks will be generated per revolution of' said distrib- - utor. A further object of'this invention consists in electrically connecting a group of at .least two contiguous contact pieceswith a spark plug and ‘ by providing an interrupter which opens at times `for controlling the first spark of an ignition pe riod of each group, While the sparks coordinate This arm, which is not illustrated, and the dis- ` tributor arm 5’ are mounted upon the shaft 9 which carries the interrupter cam l0` and the magneto rotor» il. - If, as illustrated, for igniting a twelve-cylinder four-cycle engine an ignition apparatus is used which per revolution of the ca-m shaft generates twenty-four high-voltage impulses, then these impulses follow each other on each one of the two spark plugs of a cylinder at an angle differ 40 ence of 30 degrees taken on the crankshaft. For instance, if the ñrst spark in each cylinder jumps - over at 40° before the upper dead-center 'posi tion, the second ignition will occur-at 10° before ` said dead-center position. In the case of high-speed engines it can be diñicult to open the interrupter` or interrupters several times at each ignition period. However, a single opening of the interrupter, namely for the ñrst spark, is quite suiiicient. The interrupter may remain open during the second high-voltage impulse. The increase and decrease, respectively, of magnetic flux in the cores of the coils occurs in the cited example at an adopted speed of the magneto of 2500 revolutions per minute 60,000 times per minute, that is rapidly enough, that the 2,412,690 3 slope of the ilux curve relative to the induction of the ignition voltage is still sufficient with the interrupter being open. The second ignition oc 4 1. In a high tension ignition system for inter nal combustion engines comprising a source of current,y a. primaryl winding anda -secondaryl curs in this case at a moment, which is advanced winding, and an interrupter in circuit with said primary winding, a distributor in circuit with said secondary winding including a rotary dis tributor lever driven by the engine synchronously with said interrupter and a plurality of contacts distributed circumferentially around the rotary by the so-called breaking-off angle of about 5° to 6°, that‘ means inthe chosen numerical example 15-16" before the upper dead-center position. Correspondingly, if the number of high-voltage impulses per ignition period is three orv more,` the interrupter must only beopened for generating the first spark of the period in each cylinder and may remain open during the rest of said ignition period. In a magneto, wherein the changes of flux occur, for instance, every 20° taken on the l crankshaft of a twelve-cylinder four-cycle engine, 15 wherein, therefore, thirty-six changes of ñux take axis of said lever adapted to be successively con tacted thereby, said ignition system being adapted to deliver to said distributor lever at least one high voltage impulse for each of said contacts, a lplurality of adjacent contacts each being con nected to a common spark plug terminal to fire »v across the spark gap thereof a plurality of times place per revolution of the cam shaft, that is al; a small phase displacement in the same igni three changes of ilux per ignition process, only tion period. , two changes of flux, for instance, that means the _2. An apparatus as set forth in claim 1 where first and the second .change of flux or the ñrst 20 in said source of current is a multipole magneto and third one are used for the ignition, while the delivering per revolution of said distributor lever generation of a spark upon the third or the second a number of high-voltage impulses at'fleast’equal change of flux, respectively, is .prevented in any to the number of said contacts, the synchronous known manner. drive between said distributor lever and inter 'I'he use ofthe 'ignition apparatus according tov 25 rupter being so arranged that the contacts of the invention is, ofcourse, not limited upon mag the interrupter» are opened only at the time of netos for twelve-cylinder four-cycle engines. contact of said distributing lever with each first They are as well adapted for magnetos of two one ofthe adjacent contacts which are connected cycle engines and any number of cylinders. to a single spark plug. What I claim is: > _ . so ' WALTER QCHSENBEIN.