RU240508U1 - Ignition device for an internal combustion engine - Google Patents

Abstract

This utility model relates to automotive electronics, specifically, ignition systems. The ignition device for an internal combustion engine features increased spark discharge power, which improves the efficiency of ignition and combustion of the air-fuel mixture in the engine. The ignition device for an internal combustion engine utilizes a bridge circuit, which is achieved by incorporating a second half-bridge driver and two transistor switches. This reduces the output voltage of the high-voltage pulse voltage converter, thereby increasing the device's reliability. 8 fig.

Description

The utility model relates to automotive electronics, in particular to automotive ignition systems, and can be used in ignition systems of internal combustion engines to improve the efficiency of ignition and combustion of the air-fuel mixture in an internal combustion engine, including during its start-up and operation in all modes.

An ignition coil with a control and starting device capable of reverse polarity is known (US Patent No. 6,425,383 IPC F02P 3/08, published July 30, 2002), comprising a battery power source, a coil control unit including a control circuit and an ignition coil excitation circuit, which, in turn, consists of first and second subcircuits that serve to direct and excite electric current through the ignition coil. The control circuit is connected to the excitation circuit and serves to control and activate the excitation circuit. A capacitor is connected in parallel to the primary winding of the ignition coil, which, together with the inductance of the primary winding, forms an oscillatory circuit, which leads to the occurrence of an oscillatory process, and accordingly to a periodic change in the polarity of the voltage on the primary and secondary windings of the ignition coil.

The disadvantage of this device is the insufficient power of the spark discharge due to the low voltage of the on-board network, which powers the excitation circuit of the ignition coil.

A high-frequency plasma generation system and high-frequency plasma ignition system are known (US Patent No. 8552651 IPC H05H 1/50, published October 8, 2013), comprising a half-bridge circuit comprising a half-bridge driver controlling two electronic transistor switches, the output of which is connected to a magnetic resonance section consisting of a resistor, a capacitor, and the primary winding of an ignition coil, and used as a frequency multiplier between a discharge circuit and a power amplifier. The secondary winding of the ignition coil, a resistor, an inductor, and a capacitor form a discharge circuit. When the frequencies of the magnetic resonance section and the discharge circuit coincide, the voltage amplitude across the spark plug spark gap increases, and a discharge occurs.

The disadvantage of the high-frequency plasma generation system and high-frequency plasma ignition is the insufficient power of the spark discharge due to the low voltage of the on-board network, which powers the high-frequency plasma ignition circuit, and the difficulty of setting the resonance mode necessary for the operation of the device.

An ignition device for an internal combustion engine is known (US Patent No. 9970406 IPC F02P 9/00, F02P 11/00, published 15.05.2018), comprising a half-bridge circuit including a half-bridge driver that controls two electronic transistor switches, to the junction of which the first terminal of the primary winding of the ignition coil is connected, the second terminal of the primary winding of the ignition coil is connected to the middle terminal of a high-voltage source - a stabilized DC / DC converter, the secondary winding of the ignition coil is connected to a spark plug. The device also contains a primary winding current sensor, which is connected via a converter and a comparator to a control device, which, in turn, also controls a signal generator. The start of operation of the device is determined by a spark timing sensor, which is connected to a signal generator, the output of which is connected to the half-bridge driver.

The disadvantage of this ignition device for an internal combustion engine is the need to use high voltage to power the half-bridge circuit, obtained using a DC/DC converter, which does not allow achieving high reliability of the device, as well as insufficient spark discharge power.

The closest to a utility model and adopted as a prototype is a capacitor ignition system (US Patent No. 6,662,792 IPC F02P 3/08, published 16.12.2003), comprising a half-bridge driver, two transistor switches connected in a half-bridge circuit and controlled by the half-bridge driver, a high-voltage pulse voltage converter, which serves to power the half-bridge circuit, a capacitor connected between the transistor switches and the terminal of the primary winding of the ignition coil, the second terminal of the primary winding of the ignition coil is connected to the negative terminal of the vehicle's on-board network, and the secondary winding of the ignition coil is connected to the spark plug. The ignition timing and its duration are determined by a microcontroller ignition control system.

The disadvantage of this capacitor ignition system is the need to obtain a high supply voltage for the half-bridge circuit (300-400 V), which reduces the reliability of this system operating under difficult conditions due to the increased likelihood of electrical breakdown of the high-voltage pulse voltage converter transformer.

The problem that the utility model is aimed at solving is the creation of an ignition device for an internal combustion engine with increased spark discharge power and increased reliability due to a decrease in the output voltage value of the high-voltage pulse voltage converter.

The technical result is an increase in the reliability of ignition of the air-fuel mixture in various operating modes of internal combustion engines.

The technical result is achieved due to the fact that the ignition device for an internal combustion engine, comprising a high-voltage pulse voltage converter, the inputs of which are connected to the positive and negative terminals of the vehicle's on-board network, a first half-bridge driver, to the first and second outputs of which the first and second transistor switches are connected, respectively, the upper terminal of the first transistor switch is connected to the output of the high-voltage pulse voltage converter, the lower terminal of the second transistor switch is connected to the negative terminal of the vehicle's on-board network, a capacitor connected on one side to the connection point of the first and second transistor switches, and on the other side to the first terminal of the primary winding of the ignition coil, a spark plug connected to the secondary winding of the ignition coil, wherein it is provided with an additional second half-bridge driver, a third transistor switch connected to the first terminal of the second half-bridge driver, a fourth transistor switch connected to the second terminal of the second half-bridge driver, the connection point of the third and fourth transistor switches is connected to the second terminal of the primary winding of the ignition coil.

The essence of the ignition device for an internal combustion engine is its construction according to a bridge circuit; for this purpose, a second half-bridge driver and two transistor switches were introduced, which made it possible to reduce the output voltage of the high-voltage pulse voltage converter and, thereby, increase the reliability of the device.

A unique feature of this technical solution is that, in the absence of a signal from the spark timing sensor, the first and fourth electronic transistor switches are open, while the second and third electronic transistor switches are closed. The capacitor is charged to the output voltage of the high-voltage pulse voltage converter (the supply voltage of the bridge circuit). At the moment of spark discharge, the first and fourth electronic transistor switches close, while the second and third electronic transistor switches open. The capacitor voltage is connected in series with the supply voltage of the bridge circuit and applied to the primary winding of the ignition coil, ensuring reliable spark gap breakdown.

Fig. 1 shows a structural diagram of an ignition device for an internal combustion engine.

Fig. 2 shows the timing diagram of the voltage at the output of the spark timing sensor.

Fig. 3 shows the timing diagram of the voltage at the output of the pulse generator.

Fig. 4 shows the timing diagram of the voltage at the output of the pulse generator.

Fig. 5 shows the timing diagram of the voltage at the input of the first half-bridge driver.

Fig. 6 shows the timing diagram of the voltage at the input of the second half-bridge driver.

Fig. 7 shows the timing diagram of the voltage on the primary winding of the ignition coil.

Fig. 8 shows the time diagram of the current in the primary winding of the ignition coil.

The structural diagram of the ignition device for an internal combustion engine (Fig. 1) contains a pulse generator 1, to the input of which a crankshaft position sensor is connected, the output of pulse generator 1 is connected to the first input of multiplication circuit 2, the output of pulse generator 3 is connected to the second input of multiplication circuit 2. The output of multiplication circuit 2 is connected to the input of the first half-bridge driver 4, and to the input of signal inverter 5, the output of which is connected to the input of the second half-bridge driver 6. The control input of the first transistor switch 7 is connected to the first (upper) output of the first half-bridge driver 4, and the control input of the second transistor switch 8 is connected to the second (lower) output of the first half-bridge driver 4. The upper output of the first transistor switch 7 is connected to the output of high-voltage pulse voltage converter 9, the first input of which is connected to the positive terminal (+E) of the vehicle's on-board network, the second input of which is connected to the negative (-E) terminal of the vehicle's on-board network. The lower terminal of the second transistor switch 8 is connected to the negative (-E) terminal of the vehicle's on-board network.

The control input of the third transistor switch 10 is connected to the first (upper) output of the second half-bridge driver 6, and the control input of the fourth transistor switch 11 is connected to the second (lower) output of the second half-bridge driver 6. The upper output of the third transistor switch 10 is connected to the output of the high-voltage pulse voltage converter 9, and the lower output of the fourth transistor switch 11 is connected to the negative (-E) output of the vehicle's on-board network. A capacitor 14 is connected between the connection point of the first transistor switch 7 and the second transistor switch 8 and the first output of the primary winding 12 of the ignition coil 13, and the connection point of the third transistor switch 10 and the fourth transistor switch 11 is connected to the second output of the primary winding 12 of the ignition coil 13. The power inputs of the first 4 and second 6 half-bridge drivers are connected to the positive (+E) output and to the negative (-E) output of the vehicle's on-board network. The secondary winding 15 of the ignition coil 13 is connected to the spark plug 16.

The ignition device for an internal combustion engine works as follows.

At the moment t0 of arrival of the positive edge of the pulse (Fig. 2) from the crankshaft position sensor, pulse generator 1 is started, at the output of which a voltage pulse is formed (Fig. 3), the duration of which (t0-t1, t2-t3) determines the duration of the discharge in spark plug 16. This pulse is fed to the first input of multiplication circuit 2, to the second input of which high-frequency pulses (Fig. 4) are fed from pulse generator 3. At the output of multiplication circuit 2, at the input of the first half-bridge driver 4 and at the input of signal inverter 5, a sequence of high-frequency pulses appears (Fig. 5), the duration of which (t0-t1, t2-t3) is determined by the duration of the pulse from the output of pulse generator 1. From the output of signal inverter 5, the inverted sequence of pulses (Fig. 6) is fed to the input of the second half-bridge driver 6. The first (upper) output of the first driver Half-bridge 4 controls the first transistor switch 7, the second (lower) output of the first half-bridge driver 4 controls the second transistor switch 8. The first and second transistor switches are turned on and off alternately, which ensures the absence of shoot-through current through them. The first (upper) output of the second half-bridge driver 6 controls the third transistor switch 10, the second (lower) output of the second half-bridge driver 6 controls the fourth transistor switch 11. The third and fourth transistor switches are turned on and off alternately, which also ensures the absence of shoot-through current through them.

The supply voltage of the bridge circuit is supplied from the output of the high-voltage pulse voltage converter 9, the first input of which is connected to the positive terminal (+E) of the vehicle's on-board network, the second input of which is connected to the negative (-E) terminal of the vehicle's on-board network.

In the absence of a trigger signal from pulse former 1, active levels of control signals are established at the first output of the first half-bridge driver 4 and at the second output of the second half-bridge driver 6, which ensures the open state of the first 7 and fourth 11 transistor switches. At the second output of the first half-bridge driver 4 and at the first output of the second half-bridge driver 6, there are no control signals, which ensures the closed state of the second 8 and third 10 transistor switches. In this case, capacitor 14 is charged to the output voltage level of high-voltage pulse voltage converter 9 along the circuit: output of high-voltage pulse voltage converter 9, first transistor switch 7, capacitor 14, primary winding 12 of ignition coil 13, fourth transistor switch 11, negative (-E) terminal of the vehicle's on-board network.

In the time periods t0-t1, t2-t3 (Fig. 5, 6) the first 7 and fourth 11 transistor switches are turned on and off simultaneously, the second 8 and third 10 transistor switches are also turned on and off simultaneously, but in antiphase with respect to the transistor switches 7 and 11. In this case, an alternating high-frequency voltage appears in the diagonal of the bridge between the connection points of the transistor switches 7 and 8, and the transistor switches 10 and 11. At the moment of time t0 and t2, the first 7 and fourth 11 transistor switches are closed, and the second 8 and third 10 transistor switches are opened, whereby a charged capacitor 14 is connected to the primary winding 12 of the ignition coil 13 in series with the output voltage of the high-voltage pulse voltage converter 9 through the open second 8 and third 10 transistor switches. In this case, at the moment of time t0 and t2 of the start of spark formation, a voltage appears on the primary winding 12 of the ignition coil 13 that is twice as high as the output voltage of the high-voltage pulse voltage converter 9 (Fig. 7), which provides at these moments an increased current in the primary winding of the ignition coil (Fig. 8) and, accordingly, an increased power of the spark discharge.

In the ignition device for the internal combustion engine, the first 4 and second 6 half-bridge drivers of the L6384 type were used, transistor switches 7, 8, 10 and 11 were built on field-effect transistors of the IRFP350PBF type.

Thus, the construction of an ignition device for an internal combustion engine using a bridge circuit provides increased spark discharge power with a decrease in the supply voltage of the bridge circuit, which leads to an increase in the reliability of ignition of the air-fuel mixture in the internal combustion engine.

Claims (1)

An ignition device for an internal combustion engine, comprising a high-voltage pulse voltage converter, the inputs of which are connected to the positive and negative terminals of the vehicle's on-board network, a first half-bridge driver, to the first and second outputs of which the first and second transistor switches are connected, respectively, the upper terminal of the first transistor switch is connected to the output of the high-voltage pulse voltage converter, the lower terminal of the second transistor switch is connected to the negative terminal of the vehicle's on-board network, a capacitor connected on one side to the connection point of the first and second transistor switches, and on the other side to the first terminal of the primary winding of the ignition coil, a spark plug connected to the secondary winding of the ignition coil, characterized in that the ignition device for the internal combustion engine is provided with an additional second half-bridge driver, a third transistor switch connected to the first terminal of the second half-bridge driver, a fourth transistor switch connected to the second terminal of the second half-bridge driver, the connection point of the third and fourth transistor switches is connected to the second terminal of the primary winding of the ignition coil.