RU2037069C1 - Ignition system for internal combustion engine - Google Patents

Abstract

FIELD: engine engineering. SUBSTANCE: ignition system has contacts of breaker 1, ignition coil 2, transistor 3, capacitor 4, diode 5, generator 6 of blocking pulses, generator 7 of short pulses, governor of duration of short pulses 8, converter 10 for converting frequency into voltage, and threshold element 11. EFFECT: enhanced reliability. 2 dwg

Description

 The invention relates to electrical equipment of internal combustion engines, in particular to a system for igniting a fuel-air mixture of an engine, mainly used in automobiles.

 The invention is known in which an ignition system for internal combustion engines is described, comprising interrupter contacts, in parallel with which a transistor, capacitor and diode are connected, an ignition coil, the primary winding of which is connected in series with interrupter contacts, a blocking pulse shaper and short pulse shaper connected in series between the collector and the base of the transistor (USSR Patent N 1644580, CL F 02 P 3/04, 1980).

 Such an ignition system has high reliability, high efficiency and provides a high and stable burning rate of the fuel mixture. An important parameter of the ignition system is the accuracy of the ignition timing. The power and fuel efficiency of the engine depend on how accurately the ignition is installed. In addition, various engine modes require some adjustment in the installation of the ignition timing for its normal operation. For this purpose, ignition timing controls are provided in the ignition system. In particular, the centrifugal regulator adjusts the ignition timing depending on the engine speed. With increasing speed, the centrifugal regulator shifts the moment in the direction of early ignition. The ignition timing must also be adjusted depending on the octane rating of the fuel used. Thus, both the centrifugal ignition timing controller and the octane corrector are necessary so that at all engine speeds the maximum possible engine power is achieved i.e. optimal coordination of the characteristics of the ignition timing controller with the actual burning rate of the fuel mixture.

 However, due to the technological spread of the characteristics of the centrifugal regulator, as well as the mismatch of the properties of the used fuel with the specified standards, it is not possible to achieve optimal coordination of the characteristics of the centrifugal regulator with the real burning rate of the fuel. In practice, coordination is achieved only in a rather narrow range of changes in engine speed. In the rest, the inconsistent speed range, engine power is reduced, and its efficiency is reduced. Therefore, the known ignition system does not allow the effective use of the capabilities of the engine with a wide range of changes in its speed.

 A known ignition system for internal combustion engines, comprising, in series, connected between the first and second power buses, the primary winding of the ignition coil and interrupter contacts, in parallel with which an emitter and collector of a transistor are connected (autoswitch N 929883, class F 02 P 3/04 prototype) .

 But in the case of forced use of fuel with a low octane rating, a decrease in engine power occurs. This is mainly due to the fact that at increased engine speeds, its detonation characteristic for low-octane fuel has an upward section. Therefore, at these speeds, the characteristic of the ignition timing control turns out to be inconsistent with the burning rate of the fuel. This leads to lower engine power and higher fuel consumption.

 The purpose of the invention is the expansion of the functionality of the ignition system to match the characteristics of the ignition timing adjuster with the actual combustion parameters of the low octane fuel mixture.

 This goal is achieved by the fact that in the ignition system for internal combustion engines, containing the primary winding of the ignition coil and the interrupter contacts connected in series between the first and second power rails, the emitter and collector of the transistor are connected in parallel, a capacitor, a diode driver of blocking pulses are introduced in accordance with the invention , short-pulse shaper, short-pulse duration adjuster, key, frequency-to-voltage converter and threshold element, with condensation the torus and diode are connected in parallel to the breaker contacts, the transistor collector is connected to the input of the blocking pulse shaper, the output of which is connected to the first input of the short pulse shaper, the second input of which is connected via a key to the short pulse generator, the output of the short pulse shaper is connected to the base of the transistor and to the input a frequency to voltage converter, the output of which is connected through a threshold element to the control input of the key.

 Figure 1 shows the connection diagram of the elements of the system; figure 2 characteristic of the ignition timing controller.

 The ignition system contains (figure 1) contacts 1 of the chopper, connected in series with the primary winding of the ignition coil 2. In parallel with the contacts of the chopper, a transistor 3, a capacitor 4, and a diode 5 are connected. The collector of the transistor 3 is connected to its base through a blocker of pulse pulses 6 and a driver of short pulses 7.

 The short pulse duration adjuster 8 is connected to the control input of the short pulse shaper 7 via a key 9. The control input of the key 9 is connected to the output of the short pulse shaper 7 by means of a frequency to voltage converter 10 and a threshold element 11 connected in series.

 In the initial state (engine idle speed), the key 9 is open and the short pulse duration adjuster 8 acts on the short pulse shaper 7. At the output of the shaper 7, the pulse duration is determined by the position of the adjuster 8. As the engine speed increases, the pulse frequency from the output of the shaper 7 also increases. The voltage at the output of the converter 10 also increases. At a certain engine speed (n1, Fig. 2), corresponding to the inflection point of the detonation characteristic of the engine for low-octane fuel, the voltage at the output of the converter 10 will reach the threshold of the threshold circuit 11. The latter starts to switch, locking the key 9. This leads to the fact that the pulse duration at the output of the shaper 7 begins to decrease. A further increase in engine speed leads to an even greater decrease in the duration of the pulses from the output of the shaper 7, and at a speed of the engine (n2) these pulses will have a minimum duration. Further, the duration of these pulses remains almost constant. At the maximum specified duration of short pulses at the output of the shaper 7, the resulting characteristic of the ignition timing controller will correspond to the curve "g" (Fig. 5). Prior to engine revolutions (n1), the controller characteristic has a gentle slope. In the speed range (n1 n2), the controller characteristic has an upward section. Starting from revolutions n2, the characteristic of the controller differs little from the characteristics of the centrifugal controller and the magnitude of the ignition timing, in this part of the characteristic, when exposed to the setter 8 changes slightly. By smoothly changing the pulse duration at the output of the shaper 7, it is possible to obtain a range of characteristics of the ignition timing, enclosed between the curves "d" and "g". Acting on the adjuster 8, you can select any of the desired characteristics from this area with the engine running in order to obtain a match of this characteristic with the actual burning rate of the fuel mixture when using low octane fuel.

 The proposed technical solution extends the functionality of the ignition system. It makes it possible to effectively use the engine in the entire range of changes in its speed. In addition, the proposed ignition system allows to eliminate the detonation combustion of the fuel mixture in cases of forced use of fuel with a low octane rating.

 Additional benefits of this system are fuel economy, reduced exhaust toxicity and increased engine life.

 Prototypes of the proposed ignition system were tested on VAZ cars. The application of this technical solution does not require any changes in the classical system. The block containing the elements (3, 5, 6, 7, 8, 9, 10, 11) is fixed to the "mass" of the car either near the ignition coil or in the passenger compartment, and its two leads are connected to the terminals of the ignition coil.

Claims (1)

 IGNITION SYSTEM FOR INTERNAL COMBUSTION ENGINES, containing the primary winding of the ignition coil and the interrupter contacts connected in series between the first and second power buses, in parallel with which the emitter and collector of the transistor are connected, characterized in that, in order to expand the capabilities of the ignition system, a capacitor, a diode, and circuits are introduced blocking pulses, short-pulse shaper, short-pulse duration adjuster, key, frequency-to-voltage converter and threshold element, at the capacitor and the diode are connected in parallel with the contacts of the chopper, the collector of the transistor is connected to the input of the blocker of the pulse pulses, the output of which is connected to the first input of the generator of short pulses, the second input of which is connected via a key to the generator for the duration of short pulses, the output of the generator of short pulses is connected to the base of the transistor and the input a frequency to voltage converter, the output of which is connected through a threshold element to the control input of the key.