DE1464045B2 - IGNITION SYSTEM FOR COMBUSTION MACHINERY - Google Patents

Description

1 2

The invention relates to an ignition system that makes the machine conductive and non-conductive. At sol-

for internal combustion engines with an electrical chip system has an increased service life

power source, an ignition coil, a distributor, the breaker contacts exposed because the

the ignition coil with a spark discharge device voltage and current requirements for the

device connects, and with a transistor that reduces a 5 clock to that value considerably

Emitter electrode and a collector electrode are only used to switch the transistor

shows that a series circuit with the voltage is necessary.

source and the ignition coil forms, and the usually Although such with transistors working anelectrically is biased so that it has proven to be of some use electrically is conductive, so that the circuit between the span- ίο they are nevertheless ultimately different from the mechanical power source and the ignition coil is closed. Interrupter contacts dependent. That is, at high

Motor vehicle machines are running at higher speeds. Machine speeds are the idle time machine efficiency and for higher machines still relatively short, and the coil that Working speeds developed. The compression that is charged by the transistor becomes re-conversion ratios the machine has been increased to 15 to in many cases insufficiently charged. Go on To get an increased efficiency, however, have to go at higher machine speeds these increased compression ratios and mechanical breaker contacts still have the Machine speeds on the other hand to the ar- tendency to jump, increasing the total time that When the ignition is ready, the requirements that are available for charging the coil continue to be made the usual ignition system with interrupter and 20 is shortened. It can therefore be seen that although Ignition coil are extremely difficult to meet. with such a mechanically switched, with trans-

These higher demands on the operation of the transistor-working ignition system cause certain advantages of the ignition, even if they have initially been maintained, these systems can still be satisfied by conventional ignition systems, practically the same disadvantages or undesirable rapid destruction. For example, a breaker and coil are limited in order to have a breaker and coil in the 25 properties of the usual ignition system with sub-range higher machine speeds,
A further modification of the ignition system, which is explained above with a shorter idle time of the breaker contacts in the transistors, uses higher machine speeds the ignition coil a contactless pulse generator, which is formed from a maim range of low machine speeds 30 magnetic response part or scanner, often the danger exposed to oversaturation. which cuts a second magnetic field in order to

Furthermore, the closing and the sub-magnetic field disturbances are caused, which are used to break the circuit through the interrupter, an assigned transistor in contact by a cam, which actuates in a temporal relationship to the rotation of the machine, to work the machine will. 35 tend to do. This basic design has the advantage that if the machine speed increases, the undesired properties of the increases, the control frequency increases, mechanical breaker contacts are eliminated by the cam. As a result of this increased frequency, however, this type of circuit results in a different frequency and the masses of the corresponding construction disadvantages. For example, the output chip often goes into the state referred to as "interruption of the magnetic response part from the contact jumping", which indicates that the speed at which the magnetic field opens the breaker contacts during the idle period depends on the magnetic Response part is traversed during the time during which the charging. As a result, it is at low speed, the ignition coil must be done, not in a stable, e.g. B. the start of the machine, difficult to stay from the closed position. Attempts to get a proper 45 magnetic response part an output free closing of the breaker contacts during th, which is sufficient to operate the transistor,
Higher machine speeds to be guaranteed. B. by the arrangement of a lower temperature of the environment and, as a result, working pressure spring, which generates the changing temperature of the response part ver-interrupter contacts in the direction of the contact 50 changing voltages. These changes have made the problem of contact even more difficult. table response part is so reduced that it is

Furthermore, higher ignition voltages mean that actuation of the ignition system is not sufficient.

faster corrosion and destruction of the under- Furthermore, ignition systems must be accelerated and /

causes breaker contacts, which in themselves are 55 or delayed, and this depends on factors

Are subject to oxide formation. for example the speed of the machine and

Various ignition systems are so far aimed at attempting the load. Ignition systems, which pulse generator have become known, which are used in the usual breaker according to the description above Ignition system to solve occurring problems. At- unable to work over the full range of the machine, for example is described in the British patent specification 60 to accelerate speeds properly 951 359 proposed that transistors be implemented or delayed. It is believed that this tion of the switching function of loading the coil to use at least in part on the various vortices, whereby the interrupter contacts for currents that arise within the response part, this particular function has been replaced; however and on the capacitive feedback in the dem are added to the coil associated with these transistors working with the magnetic response part the usual breaker contacts are still to be traced back. Such changes in used and operated in the usual way to allow the binding with changes in the ambient temperature transistor in relation to time to the revolutions result in a final output in the ignition coil,

which does not conveniently predict with sufficient accuracy can be to enable a perfect compensation.

An ignition system with capacitive energy storage is also known. With this system loads a DC power source on a capacitor, which is subsequently discharged through a transistor. As a result of the difficult current conditions and the associated high costs, such are capacitive Systems have so far practically not been used.

Other variations of transistorized ignition systems have been used, however does not have any of these plants to any appreciable extent, especially in the automotive industry, Entrance found.

The object of the invention is to provide a transistorized ignition system of the type mentioned in the introduction To create way in which the control of the transistor is improved, so that the concerned Disadvantages of known transistor ignition systems are avoided.

This object is achieved in an ignition system of the type mentioned at the outset according to the invention a light-triggered semiconductor arrangement which is connected to the voltage source in parallel with the transistor and which when turned on forms a shunt with the transistor, whereby the transistor becomes non-conductive and discharges the ignition coil via the spark discharge device, so that an ignition spark is caused by a facility that is temporally related to the work of the Internal combustion engine directs a light beam against the light-triggered semiconductor arrangement and through a signaling device that responds to the inductive voltage generated when an ignition spark is initiated is, responds and thereby applies a signal voltage to the base electrode of the transistor, whereby the Transistor is held in the non-conductive state for a desired period of time is released.

The invention achieves proper control of the transistor, which in turn leads to this leads that the ignition system in all areas of the machine speed, especially at high machine speeds, works flawlessly.

An embodiment of the invention is described below in connection with the drawing, for example explained.

F i g. 1 is a circuit diagram of an embodiment of an ignition system according to the invention, and FIG

F i g. FIGS. 2 through 7 are graphical representations of curves showing the operating characteristics of parts of FIG Ignition system according to FIG. 1 play.

In the drawings, F i g. 1 again shows an embodiment of the invention comprising an electrical power source 10, a silicon controlled rectifier (SCR) 12, and a PNP transistor 14 operatively connected to an ignition coil 16 having a primary winding 18 and a secondary winding 20. The secondary winding 20 may, as indicated, be suitably connected to the rotating arm 22 of an ignition distributor 24 which has distributor segments or terminals 26 which are each operatively connected to the spark plugs 28 of the internal combustion engine 29, the parts being grounded at 30 .

An electrical conductor 32 in which an ignition switch 34 and resistors 36 and 38 are connected in series is to the positive terminal 40 of the electric power source 10 and to the emitter electrode 42 of the transistor 14 connected. A conductor 46 is connected to the collector electrode 44 of the transistor 14, the via a coil or winding 50 and a resistor 52 to a terminal 48 of the Ignition coil 16 is connected. With the terminal 54 of the ignition coil 16, a conductor 56 is connected to

ίο the distributor rotor 22 leads while a connection 58 of the ignition coil 16 to the negative terminal 60 of the power source through a conductor 62 is electrically connected.

A movable screening or blind mechanism, as represented by a disc 64 which is provided with a plurality of slots 66, is between a light source, e.g. B. a lamp 68 and the photoconductive device 12, interposed. The disc 64 is timed to the rotor 22, z. B. rotated by an appropriate transmission 70, which is driven by the internal combustion engine 29. The slits 66 are of such a size and are arranged so that they allow the light emerging from the light source 68 to pass through one of the slits 66, as indicated schematically by the line 67, and to hit the controlled rectifier 12 when the rotor 22 generally overlies one of the manifold segments 26.

A conductor 72 connected at one end to conductor 32 at a point between resistors 36 and 38 and connected at its other end to conductor 62 is in series with the Rectifier 12 and a resistor 74 connected.

A conductor 76 connected to conductor 32 by way of conductor 72 is in series with one Resistor 78 and conductors 80 and 82 connected, which are parallel to each other and also with the conductor 62 are connected. The conductor 82 connects the light source 68 in series with the conductor 62, during the Conductor 80 contains diodes 84, 86 and 88 connected in series, which together act as voltage regulators for the Light source 68 serve.

With the control electrode 90 of the rectifier 12, a resistor 92 is connected to its other Ends with conductor 72 at a point between rectifier 12 and resistor 74 connected. The resistor 92 is preferably a combination of a resistor and a thermistor. Furthermore, a coil or winding 98 is connected to the point 94 by a conductor 96 the other end of which is connected to the base electrode 100 of the transistor 14.

A zener diode 102 connected to conductors 32 and 46 in parallel with transistor 14, is provided as protection for the transistor 14 in the event that excessively high voltages are to occur across it. A switch 104 can be provided which is closed during the start-up of the internal combustion engine thereby shunting resistor 36 during the start-up period. After this Once the machine itself is working, the switch 104 is opened, causing the resistor 36 in the Circuit is arranged.

For the purpose of describing the operation of the invention, let the following conditions exist accepted

a) ignition switch 34 is closed,

b) shunt switch 104 is open,

c) the connected internal combustion engine, which contains spark plugs 28, is running,

d) the rotor 22 is rotated and is at the beginning of the observed moment between successive connections 26, and

e) the shutter mechanism or the disc 64 lies because of the bound rotational movement relative to the runner 22 in a position in which all openings or slots 66 with the Light source 68 and rectifier 12 are out of alignment.

Under the conditions assumed above, it can be seen that when the switch 34 is closed, the Current source 10 biases the emitter and base circuits 100 of transistor 14 in one direction, which causes the emitter-collector circuit to be conductive. The value of the resistance of the Coil winding 98 and the resistance value of resistor 74 are selected so that a sufficient Base current flows when the ignition switch 34 is closed, so that the transistor 14 of the Emitter 42 to collector 44 is completely conductive.

During this period, still under the assumed conditions, an essentially flows constant current not only through the primary winding 18 of the ignition coil 16, but also further through winding 50, winding 98 in the transistor base circuit, resistor 74 and the light source 68. The coils 50 and 98 in conjunction with the associated core 106 'can be regarded as constituting a transformer as will be apparent from the description below is.

When the disk 64 and the rotor 22 move from their previously assumed positions to the positions shown in FIG. 1 position shown, the light supplied by the light source 68 can be through a in Alignment lying slot 66 of the disc 64 pass through and impinge on the rectifier 12. This exposure of the rectifier 12 causes it to become conductive, which ultimately results in a reduction in size of the current in the coil winding 18 to the value zero with the resultant Coincidence of the previously formed field around the winding 18 results. This diminution of the stream in the primary winding 18 produces a voltage rise and a voltage rise in the secondary winding 20 Sparking process at the corresponding spark plug 28 through the conductor 56 and the rotor 22.

The way in which this current reduction is obtained in the primary winding 18 of the coil is generally as follows. As a result of the rectifier 12 becoming conductive a portion of the current of transistor base 100 through rectifier 12 is shunted. the Reducing the current flow through the base 100 immediately results in a significant reduction in the Current flow through the transistor-emitter-collector circuit, the winding 50 and the primary winding 18 of the ignition coil 16. The reduction in the current flow through the winding 50 causes the The field previously built up around it begins to collapse, which in turn causes the coil 98 of the A voltage is induced in the transistor base circuit. The voltage induced in coil 98 has a direction in which it seeks to reverse the bias of transistor 14 or, in other words, to cause the base 100 to become relatively more positive. The base 100 on this Way is relatively more positive, causes a further reduction in the current flow through the transistor-emitter-base circuit 42, 100, which in turn causes a further reduction in the current flow through the coil 50. This is repeated continues, thereby causing the current to flow through

ίο the emitter-base circuit, the current flow through the coil 50 and the flow of current through the primary winding 18 of the ignition coil 16 is terminated.

The collapse of the field around winding 50 causes the induced voltage across the Base 100 changes from a negative to a substantially positive value. after the positive voltage at the base 100 approximately reaches its maximum value, the voltage begins of winding 98 to drop, thereby causing the induced positive voltage at the base 100 reduces in value so that it approaches zero voltage and then again negative _ will. During the period during which (the transistor base 100 is at a positive voltage and during the period during which the induced voltage is applied to the Winding 98 coincides, the controlled silicon rectifier 12 is still conductive State although the disk 64 has been rotated to a position in which the light source 68 emerging light cannot impinge on the rectifier 12. The persistence of the electric Conducting a light-triggered rectifier, even after the light is no longer available, is a peculiarity of one controlled silicon rectifier. Accordingly, the invention provides to the use of a controlled Silicon rectifier to allow a means to forcibly cause the conductive to be controlled Silicon rectifier is non-conductive in relation to time to the work of the machine.

Once the induced voltage on winding 98 has completely collapsed and the base 100 has again become negative with respect to the emitter 42, the current flow through the / Emitter-base circuit and the emitter-collector circuit are restored and thereby generated a current flow through the winding 50 and the ignition coil 16. This current flow causes itself a field builds up around winding 50, which causes a second voltage in winding 98 is induced, and this voltage is in the direction of the forward bias of the transistor or with in other words, in a direction opposite to that of the first voltage applied in the winding 98 was induced. This negative voltage pulse then becomes the controlled one through conductor 96 Silicon rectifier 12 through the control electrode 90 and that connected to the conductor 72 Cathode 71 of the controlled silicon rectifier passed, whereby the current through the cathode 71 is reduced to a level below that which is necessary for the conductive state of the controlled Silicon rectifier 12 maintain. The controlled silicon rectifier is switched off and non-conductive, the current flow through the emitter-base circuit is at the set limits increased, whereby a relatively constant maximum current flow through the primary winding

7 8

18 of the ignition coil 16 is generated. The controlled one rises. A voltage drop then occurs,

Silicon rectifier is then exposed again until it reaches a zero value, generally at 132

the next sparking process that is indicated. The time interval from point 130

next spark plug 28 to reach. to point 132 is essentially the same as the inter-

FIGS. 2 through 7 graphically depict the working range between points 108 and 110 of FIG

Features of the invention according to the above determination and is consistent with it. The subsequent

writing again. For example, in Fig. 2 the increase in the current from point 110 to a maximum

Current flow in amperes through the primary winding 18 times the value at 112 causes the voltage curve

of the ignition coil 16 is recorded against the time, where FIG. 4 becomes negative and at 134 a negative

where the current units reach the ordinate axis of the dario tip, which in expressions of time is essentially

position and the time units borrowed the abscissa axis with the point 112; or something with him

form. A check of FIG. 2 shows that if it matches. A subsequent drop causes

the current conduction through the emitter collector - that the voltage again has a value of essentially

Circuit of transistor 14 is ended, the current borrowed zero assumes, as indicated generally at 136 '

through the primary coil 18 differs from one essentially 15. When comparing the curves of Fig. 4

borrowed constant value, which is shown at point 106 and 5 it can be seen that Fig. "5 is an enlargement

is reduced to zero, as represented by point 108 on the curve in FIG. Accordingly, they are

is posed. The current value remains the same during a corresponding same point with the same

relatively short length of time, denoted by the point reference number and an index. It's him-

IiO is shown to zero, at which point in time aö visible that the TeU of the voltage curve in F ig. 5,

the conduction through the emitter-collector current circuit which generally through points 128 ', 130- and

; is restored, describing a current surge 132 '; transistor 14 in ^; one

holds from zero at point 110 to the intended maxi non-conductive state (whereby the time period

mum is caused at point 112. Minor between points 108 and 110 of FIG. 2 ge ^L

Fluctuations as shown at 114, 25 create) and that the part of the curve which is general

can precede the stream, 'which in turn leads to mine through points 132' and 134 '(at the value

the maximum intended value stabilized by essentially zero) is determined, an increased

den is as indicated generally at 116. . the opposite voltage, which

F i g. 3 is directly related to FIG. 2, acts that the controlled silicon rectifier 12

d. i.e., the graph of Figure 3 indicates a 30 becomes non-conductive. This is achieved because of the

Curve again resulting from the recording of the negative

Voltage at the primary coil 18 versus time causes the current failure through the controlled voltage

is true, whereby.in the same instant as silicon rectifier 12 reduced below the level,

the one started to determine what is required to run the controlled silicon

the curve of Fig. 2 would be used. In Fig. 3 35 'to keep the rectifier in a conductive state, are the voltage units along the ordinate axis The invention has yet another character-

and the time units along the abscissa axis have an upristic characteristic which is of considerable

drawn. Benefit is. This consists as of the prominent one

From a comparison of FIGS. 2 and 3 it can be seen that during normal driving, when the current goes to zero from a maximum 4 ° propulsion condition, the voltage is generated from one value for each ignition required. Zero at point 118 to a maximum at point 120, however, increases at relatively low engines. Furthermore, the spark duration, which extends speeds, for example during the view from point 120 to point 122, or the idling of the internal combustion engine, in terms of the time essentially corresponds to 45 for each required ignition process from point 110 in FIG. 2 match. After the spark - considerable benefit, a - multiple ignition process can create a small oscillation that generally spark. This is in: indicated situations, particularly at 124, occur before the voltage useful when the starting of the internal combustion engine again etattfindet a value of substantially zero arrival at cold outside temperatures ^r.
takes. '50 These multiple sparks while behaving-

FIG. 4 graphically shows the voltage across the low speed Brenri primary winding 50, while FIG. 5 the voltage engine and during the start-up can be reproduced on the winding 98. In each figure, by selectively choosing the size of the holes, the units of tension are measured along the ordinate 66 of the disc 68 and through a corresponding axis, while the units of time are plotted along the axis of the abscissa axis of the light source. For the purpose of the 68 and the controlled silicon rectifier 12 to clarify and reproduce, the time scales are sufficient. '■: <■■ · ■''; both the Figure 4 and 5, although they are identical in other words, as long as are the controlled another sawn with reference to Figures 2, 3, 6 silicon controlled rectifier by the light source 68 and 7 is increased, which in turn equal to one ^another. 60 illuminates the cycle of pre-existence is repeated. For reference purposes, the graphical representations which lead to the ignition spark and causes the positions of FIGS. 4 and 5 are designed in such a way that they generate a second ignition spark. Since the time for a five timing equal to a timing in sparks is considerably less than the time made the Fig. 2, 3, 6 and 7 have. which can be used for the light beam 67

From Figs. 2 and 4 it can be seen that, if ^ 5 is required, on the controlled silicon equalization

the current from point 106 to zero at point richterl2 to meet and traverse it

108 changed the voltage from substantially; ^; be reminded that the aperture, or

Zero at 128 of FIG. 4 to a point at 130 an- disk 64 in accordance with the speed

speed of the internal combustion engine is rotated), it is possible for each individual. required Zundyorgang cause a plurality of ignition sparks.

This is illustrated, for example, by FIG. 6 and 7 reproduced (each representing the voltage on the _; -5 coils 50 and 98) in. Comparison with the expressions of time with FIGS. 2 and 3. From the above description it can be seen that about three ignition sparks occur in each ignition system in the ignition system, which operate under a condition jo, such as. they from the Fi g. 6 and 7 can be seen, compared to a single one who works under a _{loading 7} condition according to FIGS. Only for. the · expressions of _; Voltage values - are selected, the corresponding reference numerals of Figures 4 and 5 in Figures 6 and 7; been. , -,

. ■: -It is known that the controlled silicon rectifier also responds to infrared radiation. Hence it is not necessary. _{: That;} only such radiant energy sources _; The visible ₍ ao i light: / emit.- It is also known that as a light source 68, each one emits radiation that essentially only has a wavelength in the range , of the infrared spectrum, can be v _: \ - ■;> \ y ·. · -. ■ ·. £ -_.- _: . _; ..: - · ■: '-25

;;,; ^; It must be stated in particular that a reference to "a," lamp "; or a" light source ". Any source ypn _; radiant energy μηαί. ; »Light« or _: »light energy« ■ such.; Radiation or radiant energy,; as it is necessary to. Achieve; triggering the semiconductor. Device: 12..; ·. <.-: .- . ■■;>...; ·:

. ,, Under certain working conditions which occur at or near - ■ an ignition spark - a .35 reverse voltage in, the; Primary winding 18 induces the ignition coil 16 which is of sufficient height to cause a proportional reduction in the primary current. t> this current reduction occurs; also in the coil or winding 50, which in turn, through the core 106 ' and the winding 98, causes the transistor 14 to be switched off and become non-conductive. Once this work has been initiated, oscillations in synchronism with the natural frequency of the secondary winding 20 of the ignition coil can occur as a reflection in the primary winding 18 in the entire ignition circuit. '. ■; -. · ■. ;. :: ·. ■

In order to prevent such an effect from occurring, means are for. Compensation for the instantaneous current reduction is provided in the winding 50, which, as stated above, can occur as a result of the reverse voltage in the primary winding 18 of the ignition coil. A coil or winding 138 ^: which is attached to conductors 46 and 62 _; 55 is closed, can: create the desired compensation. The polarity of winding 138 is such that a voltage in primary coil 18 which is negative at grounded coil terminal 58 forces a current to flow in coil 138 ' which excites core' 106 '. The ampere-turns of the coil 138 are sufficient to overcome the input to the core 106 of the ¹ de-exciting ampere-turns of the winding 50, to compensate and to compensate for the mentioned oscillation of the entire ignition circuit _; 6s prevent. ■

Another advantage can be achieved through the use of ■ a resistor 140 ..; be won. The resistor 140, which is connected in series with the coil 138 , has a double function, ie> during the working period, during which the coil 138 works as a compensation means, the resistor 140 serves to increase the current flow through the coil 138 to the desired value to limit and serves during, other working periods as a load resistor for the, coil 50. Accordingly, the resistor 140 .. as. a. Calibration means for Be-J-cutting the operating characteristics of the windings 50, 98 and 138 can be considered. '".,'

The transistor 14 is a PNP transistor, but it will be apparent from the foregoing description that the invention can also be implemented through the use of an NPN ^ transistor. can be practiced, since the alternative use only requires an appropriate reversal _(of the polarities.. i, From the foregoing it can be seen that the invention maintains the selected spark setting indefinitely, because the spark process is triggered by light and, therefore, all Wear problems from the trigger mechanism can be avoided.-Another important advantage of the invention over a transistor ignition system with mechanical breaker contacts and triggered energy is that the trigger signal fed to the energy transistor according to the invention has an essentially constant value regardless of the machine speed The same advantage is also present compared to the known trigger mechanism that works without contacts and with a pulse generator. "■■

Claims (3)

"Claims:. · ^: 1. Ignition system for internal combustion engines with an electrical voltage source, an ignition coil, a distributor connecting the ignition coil to a spark discharge device; and a transistor having an emitter electrode and a collector electrode which forms a series circuit with the voltage source and the ignition coil, and which is usually electrically biased such that it is electrically conductive, so that the circuit between the voltage source and the ignition coil is completed ' is characterized by a light-triggered semiconductor arrangement (12) which is connected in parallel to the transistor (14) to the voltage source and which forms a shunt to the transistor (14) when it becomes conductive, whereby the transistor becomes non-conductive and the ignition coil (16) over the spark discharge device (28) discharges, so that an ignition spark is caused, by a device (64, 68), which in time relation to the operation of the internal combustion engine a _: Light beam against the light-triggered semiconductor . arrangement (12) directs and by a signaling device (50, 98), which refer to the inductive span . ··. voltage generated when an ignition spark is initiated and a signal voltage is applied to the base electrode (100) of the trans- . sistors (14) applies, whereby the transistor during a desired period of time in non-. conductive state is maintained. 2. Ignition system according to claim 1, characterized in that ■ that the light-triggered semiconductor . . ■ arrangement (12) consisting of a light-triggered controlled silicon rectifier consists that electrical conductors (96, 72) are provided which electrically connect the rectifier (12) and the signal device (SO, 98) to one another, and that the signal device (50, 98) responds to the termination of the ignition spark and thereby applies a second signal voltage to the rectifier (12) via the electrical conductors (96, 72) to render the rectifier non-conductive.
3. Ignition system according to claim 1 or 2, there- characterized in that the in the circuit as a result of the electrical biasing of the Transistor (14) resulting current flow takes place in a first direction and a compensation coil device (138) is provided in order to prevent current flows in a direction opposite to the first direction, which flow into the Circuit between the ignition coil (16) and the transistor (14) through the coil near the Induced at the end of the spark. 1 sheet of drawings