JPH0350386A - Ignition system for internal-combustion engine - Google Patents

Abstract

PURPOSE: To burn a mixture of a lean fuel and to permit fast multiple combustion by constituting this ignition system of a pulse transformer to be connected to a spark plug, a driver to induce a high voltage signal to a secondary coil, a controller to generate voltage on the secondary coil and a discharge detection part to control its work. CONSTITUTION: This system is furnished with a pulse transformer 44 having a primary coil 76 and a secondary coil 80 connected to a spark plug 102, a driver 46 to induce a high pressure signal to the secondary coil 80 by giving a voltage signal to the primary coil 76 of the pulse transformer 44 and a controller to generate voltage on the secondary coil 80 by giving a control signal to the driver 46. Thereafter, work of the controller is controlled by a discharge detection member by giving a discharge signal to the controller by detecting generation of discharge between the spark plug 102.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application> The present invention provides improved engine operating performance by greatly facilitating fuel mixing, controlling ignition timing, and efficiently designing ignition system components. This relates to the ignition system of an internal combustion engine.

<Prior art and its problems> In order to initiate the explosion of the air-fuel mixture in the internal combustion chamber, high energy
An ignition system is used to create an arc. The initiation of the energy arc across the spark plug gap is timed to occur a predetermined number of engine crankshaft revolutions before the piston reaches top dead center. If the spark timing is done properly, the flame from the Snow (46) spark plug will cause a pressure peak after top dead center. If the spark is too slow, the pressure in the cylinder will not be effectively output. On the other hand, if it sparks too quickly, it will create too much pressure and heat to produce any useful power.

A premature spark will cause various cylinder phenomena.

Automatic ignition of end gas (unburned fuel mixture) is due to spontaneous explosion of end gas when the temperature and pressure inside the cylinder become too high. When auto-ignition occurs in the cylinder, the pressure alternately rises and falls due to the rapid release of chemical energy, causing a sudden rise in temperature. If the rate of energy release is high enough, the vibrations within the explosive gas will cause the cylinder walls to vibrate, producing the characteristic "buzz" sound. Rapid fluctuations in the pressure and temperature of the gas in the cylinder occur after top dead center.

Quiet automatic ignition is believed by many engine designers to be desirable because when the velocity of the flame exiting the smoke/moke plug is reduced, it creates a sweep that speeds up the explosion.

Silent automatic ignition reduces residual unburnt hydrocarbons and utilizes the energy released when burned, resulting in lower hydrocarbon emissions and better fuel efficiency. Therefore,
Engine designers try to calibrate the ignition system so that the spark is early enough to start auto-ignition. However, excessive early automatic ignition must be avoided. Otherwise, the temperature inside the cylinder could become too high, heating the spark plug electrodes too much and causing the well-known phenomenon of ``pre-ignition,'' in which the explosion begins without any spark. Pre-ignition can cause damage such as piston pitting due to excessively high temperatures and pressures near top dead center. Pre-ignition manifests itself as "knocking," the sound it makes.

It is generally said that automatic ignition causes pre-ignition, and pre-ignition further causes automatic ignition.

Many factors--intake air temperature, engine speed, load, fuel mixture ratio, fuel characteristics, etc.--affect the timing of autoignition occurrence. Spark timing also directly affects fuel efficiency and harmful gas emissions. spark·
Because it is important to accurately control the timing, many engine control systems currently have a closed loop timing control system using a microprocessor. Simultaneously measure the C ramometer and the occurrence of knocking. This system processes the above data to match the predetermined automatic ignition start timing.
. Current knock detectors using spark controllers use piezoelectric transducers to detect the vibrations caused by knocking. However, this detector
Since it is not possible to sufficiently detect initial automatic ignition, it is not possible to detect the beginning of automatic ignition. It is necessary to give.

Designers of ignition systems for vehicle internal combustion engines strive to ensure that the engines burn internally at low fuel mixtures. A mixture with an air to fuel ratio of about 15:1 is said to be a stoichiometric mixture and provides all the oxygen necessary for combustion. but,
If too much air is introduced into the cylinder, ♀ elemental oxide (N
Reduce harmful emissions such as OX) and hydrocarbons. However, there is a limit to how dilute the fuel mixture can be before the spark causes an ectothermal reaction within the cylinder. Currently, the mixing ratio limit is about 20:1. Designers are working to push the limits of this air-to-fuel ratio, and it is believed that theoretically it is possible to reach about 27:1. Therefore, in modern ignition systems that require extreme mixing ratios, a transformer known as an ignition coil is mounted directly to each spark plug, often with a coil-on-plug (COP) ignition element. It is said. The size and weight of this element affect its thermal properties. operates at high duty cycles,
The coil must be large and heavy enough to prevent overheating.

Conversely, low duty cycle operation makes the coil smaller and lighter. It is better to reduce the size of the coil of a coil-on-plug because it will reduce the restrictions of engine caging. Therefore, there is a need to mount a spark plug with an element of minimum size and weight.

=25 <Configuration of the Invention> According to the present invention, an improved ignition system is provided which can provide the above-mentioned necessary characteristics. - A solution to the above prior art problem is obtained by using new ignition system components. These components take advantage of various phenomena that occur during the explosion and ignition process.

It is believed that the ignition system has three elevated phases of discharge in the spark plug gap. These are, in order from the beginning of the discharge, the dielectric breakdown phase, the arc phase, and the glow phase. In the dielectric breakdown phase, a high voltage of about 10 kV is applied to the Snomique electrode for nanoseconds (10-9 seconds).
A large army of over 1,0OOA within a short period of time called Order,
The flow flows. Because this phenomenon occurs over an extremely short period of time, on the order of 10-9 seconds, it has been impossible to measure this current value accurately because it has not been possible to obtain measuring instruments with sufficient dynamic response. This 26- current is called the ignition high frequency current. In this breakdown phase, once a conductive path is formed within the gap,
The discharge moves to the next arc phase, a low lightning pressure is applied across the gap, and a current of much greater magnitude can flow for a relatively long time.

In the final glow phase, both voltage and current are low.

Many researchers, such as Murray and Bogle, who published the paper ``Flame ignition and propagation in dilute methane-air mixtures through three phases of ignition,'' It has been argued that the arc phase and glow phase spread in the dielectric breakdown phase, and that the arc phase and glow phase not only do not contribute to the explosion, but are harmful because they corrode the plug rod.

The ignition system of the present invention employs a pulse transformer system that operates in a distinctly different manner than conventional ignition coils. An ignition pulse transformer is attached to the outer end of each smoke/smoke plug. conventionally,
One coil provided high voltage to each of the many spark plugs. In traditional ignition systems using fly-pack type transformers (i.e., coils), energy is stored in the magnetic field of the coil, increases through the current in the primary winding, and increases the voltage in the secondary winding when the magnetic field is removed. becomes zero.

Although flyback transformer coils have been used for decades, they are electrically inadequate. On the other hand,
The main advantage of the pulse transformer in the present invention is that the inductance of the secondary circuit is greatly reduced, so the spark plug ignites in a short time of 50 μs, thereby reducing multiple firings.
) 'x is possible.

Due to its low impedance, it can ignite even partially dirty spark plugs. In a pulse transformer, discharge energy is not stored as a magnetic field.

The pulse transformer simply acts as a quick Φ response step-up transformer, providing a secondary output in response to voltage spikes delivered to the primary winding.

Embodiments of the invention include detecting the occurrence and timing of spark discharges, as well as arc phase and glow phase discharges.

Using a ferrite toroidal detector to detect the breakdown current in the ignition system as a means to control the pulse transformer so as to minimize the time, Paschen's law: Dielectric breakdown voltage vb at discharge point
, the pressure P in the cylinder, and the temperature T (k is a constant).

vb = k- j As already explained, the autoignition process is evident by the abnormally high pressure and temperature fluctuations that occur K after top dead center (shaft angles between 5° and 20°). detect automatic ignition,
Means 29- The ignition system of the present invention applies a predetermined voltage (referred to as the operator voltage) across the spark plug during the engine operating cycle, subject to automatic ignition pressure and temperature fluctuations. Ru,. During automatic ignition, the pressure and temperature inside the cylinder are reduced by the breakdown voltage (according to Paschen's law)
This is instantaneous (for normal ignition, less than the breakdown voltage), so the discharge at that time only occurs during auto-ignition conditions and not during normal ignition conditions.

The sensor according to the present invention has the above-mentioned toroidal detector and detects dielectric breakdown current, so it outputs a signal indicating the occurrence of discharge. This signal is used to progressively retard the ignition timing for all or individual cylinders until autoignition ceases. In another routine, the autoignition is again modified by advancing the ignition timing to cause autoignition to occur again. In this way, a "fluctuation" of ignition timing occurs at the automatic ignition threshold (starting 30-seconds). Therefore, by activating the spark plug in a predetermined operating window after top dead center, the spark
The plug acts as an automatic ignition detector and is much more sensitive than traditional piezoelectric knock sensors.

Activation of the above plug is not to increase the explosive prosen, but only to detect automatic ignition. Using the pulse transformer of the present invention, it is possible to adjust the hover voltage to a desired value. This is difficult to achieve using conventional flyback transformer coils.

Since each cylinder in an internal combustion engine has different pressure and temperature characteristics, it is desirable to calibrate each cylinder under a certain environment. Otherwise, when a certain hover voltage is used as an auto-ignition sensor, it may incorrectly indicate auto-ignition. Calibration occurs after top dead center, during one segment of the cylinder operating cycle, and before pressure and temperature fluctuations, where the spark plug is activated through a series of voltages.

The voltage at which breakdown occurs during this calibration is used to adjust the hover voltage for that cylinder. Therefore, according to the invention, a total of three spark plug activation times occur within one piston stroke cycle.

That is, a first discharge for generating a spark, a second calibration discharge, and a third discharge for detecting automatic ignition.

As soon as the spark plug discharges, a "nucleus", a small ball of ionized gas, forms - because the fluid in the cylinder is disturbed, this "nucleus" moves from where it was at the beginning of the plug gap. . When the air-to-fuel mixing is high enough, the core induces an ectothermic reaction and rapidly grows into a spherical apron.

On the other hand, if the mixing ratios are too similar, the hot core will be cooled by the surrounding fluid, become smaller, and disappear when it moves out of the plug, making it impossible to extract useful energy from the mixture in the cylinder. The air-to-fuel mixture ratio at which internal and external heat reactions begin to occur is called the engine's lean burn limit. The inventor has discovered that microseconds (10-
It has been found that if the spark plug discharges multiple times over a short period of time (on the order of 6 seconds), the lean burn limit can be improved and a leaner fuel mixture can be used. By burning the pulse rapidly with the plug,
A series of nuclei are generated and are blown away one after another. Since each core is in close contact with each other, cooling from the open fluid is minimized. Therefore, a series of kernels remains in the cylinder for a longer period of time so that even leaner fuel mixtures can be burned. Using a pulse transformer 7, 33- enables such fast multiple combustion. This is due to the large inductance of the secondary winding when using a conventional flyback transformer coil.
It's impossible.

According to the invention, fast multiple firing of the plug is achieved by detecting the breakdown current. This signal is used to shorten the discharge cycle and initiate the next ignition cycle, causing multiple discharges in a short period of time.

Also, according to the present invention, the size and weight of the pulse transformer are minimized for structural and packaging efficiency.

Essentially, using a pulse transformer minimizes size and weight. This is important. This is because the pulse transformer is placed at the end of the spark plug where the weight of the pulse transformer affects the cantilever mounted on the plug due to engine and vehicle vibrations. , c34- The small size of the russ transformer also has the advantage of easing engine-package constraints. The size and weight of this type of pulse transformer is greatly influenced by thermal requirements. According to the present invention, detection of breakdown current is used as a means to truncate the primary current flow to the spark plug coil, thus reducing the duty cycle. Since the breakdown phase of the discharge plays a useful role in the initiation of combustion, the subsequent arc and glow phases are shortened without adversely affecting combustion. The inventor believes that Teutie cycles on the order of one order of magnitude are possible with an ignition system operating as described above. This lower duty cycle minimizes the size and weight of the pulse transformer, thus improving the engine's structural and packaging efficiency.

Hereinafter, the present invention will be explained in more detail with reference to the drawings.

Figure 1 shows the voltage characteristics of a spark plug in an internal combustion engine.The voltage, as shown by the solid line 10, continues to rise at the time of discharge, and after discharge, it suddenly drops to a small value, and the voltage is in the arc phase. Move to glow phase. A broken line 12 is the voltage between the electrodes when there is no discharge.

Figure 2 shows the current characteristics. 14 is a dielectric breakdown current, which occurs in a short time on the order of nanoseconds.

As previously noted, the ignition system according to the present invention uses detection of this breakdown current 14 for combustion detection and timing control.

FIG. 3 shows the relationship of cylinder pressure to crankshaft position. The solid line 16 is the pressure during the normal combustion process. The cylinder pressure 16 continues to rise, reaching a peak just after top dead center, and then decreasing as the cylinder volume increases. A broken line 18 represents fluctuations in cylinder pressure during automatic ignition. This is usually 5° to 20° after top dead center.
Occurs at an angle of °. This fluctuation is caused by the explosion reflected within the cylinder. During automatic ignition, the cylinder pressure 18 momentarily becomes lower than the pressure 16 during normal combustion due to fluctuations. In the present invention, this is detected as an instantaneous drop in dielectric breakdown voltage.

FIG. 3 also shows three spout lengths 46) spark plug activation timing according to the present invention. 1 morsumi pressure 2
0 is applied before top dead center to begin the combustion process.

Pulsed voltage 22 is provided at or just after top dead center as a means of calibrating the automatic ignition detection system. The pulse voltage 22 has a sawtooth waveform that increases until a discharge occurs and decreases at the time of discharge. Therefore, the total 7 molar width of the pulse voltage 22 corresponds to the cylinder pressure according to Paschen's law. Pulse voltage 22
The breakdown voltage of 37- is used to calibrate the system to accurately detect auto-ignition while allowing for variation of 37- from each cylinder. This calibration is done before the effects of auto-ignition are visible on the breakdown voltage.

Pulse 24 detects automatic ignition by applying a hover voltage adjusted to the plug electrode to cause discharge when the cylinder pressure is lower than the pressure during normal combustion and the temperature inside the cylinder rises. ,.

FIG. 4 is a block diagram of the ignition system 30 of the present invention. Ignition system 3 (1) includes an onboard ignition controller microprocessor 32 that receives input signals from an engine timing transducer 34, an engine timing controller 36, and a vehicle oxygen sensor module 38. 4
0 is powered by the vehicle battery 42 to power each element of the system. Microprocessor-32
is mounted on a spark plug driven by a dry, <-4638-
The output signal is sent to the bus transformer 44.

Engine-timing transducer 34 is provided with a Nomibus signal from a magnetic or optical sensor that detects the position of the crankshaft or camshaft to output crankshaft position. This signal is used for ignition timing and engine speed measurements.

The engine timing controller 3flj is operated by the microprocessor 32 and receives signals from the timing transducer 34 to control coolant temperature, throttle position, ambient air temperature, manifold pressure,
Aim for preferred ignition timing without inputting parameters such as load detection. A signal indicating automatic ignition is received from microprocessor 32. As previously discussed, the timing controller 36 maintains the engine at the onset of auto-ignition by retarding and then re-advancing the timing until auto-ignition is detected. This puts the ignition system into a state of automatic ignition initiation for the particular engine using the parameters that are present at any given time.

Vehicle oxygen sensor module 38 detects oxygen in the engine exhaust gas and inputs the air-to-fuel ratio to microprocessor-32. The oxygen sensor is typically a zirconium diode mounted within the engine's exhaust manifold. Signals from sensor module 38 are used to control the fuel injection system.

Microprocessor 32 receives the signals and drives the spark plug through driver 46 and Nomibus transformer 44. In Figure 5, 1. The e-bus transformer 44 and driver 46 are shown in detail. FIG. 5 shows a series of four pulse transformers 44 and drivers 46 for a four cylinder engine. One of these is indicated at 48 and surrounded by a dashed line. The other three have the same configuration. driver 46
Since it receives a 200V DC signal from the power supply 40, it is physically separated from the pulse transformer 44.

Driver 46 connects positive bus 50 and ground bus 5
A voltage of 200 V DC is applied along the line 2. The ignition signal from microprocessor 32 is sent through connector 54 along lines 56, 58, 60, 62 to each cylinder. Line 62 is to the driver and pulse transformer combination circuit 48. Line 59 is a common low voltage line for power supply 40.

The ignition signal is sent to a switching transistor 64 of the VMO8 type through an interface transformer 66 without electrostatic shielding. Diodes 68 and 70 are used for circuit protection and diode 72 is used for the flange.

41- When the ignition signal is sent along line 56, the high voltage
4 is sent along line 74 to the pulse transformer 44 and followed along line 78 to the grounded Nomibus
A voltage is applied through the primary winding 76 of the transformer.

The current flowing through the primary winding 76 (contains a pulse of high voltage through the secondary winding 80. The voltage induced in the secondary winding 80 is 446) across the spark plug gap 8.
It is applied between the two.

According to the invention, an element is provided for detecting dielectric breakdown current. This current only flows for a very short time, so
Because the high impedance of the return path to ground line 88 makes it difficult to detect that current, an alternate return path is provided that is electrically connected to the bottom of the spark plug and connected to ground line 88. A spark plug shield 86 is provided. The signal on line 88 passes through ferrite bead 90 to ground bus 52. This high frequency large current signal 42 induces lightning and pressure within the loop 92. loop 9
The output of 2 is approximately 50V and is a 10-9 second pulse. A full wave rectifier 594 rectifies this induced voltage and sends it to the microprocessor 32 through line 96.98 and connector 54.

In FIG. 6, the spark plug 102 is installed. 4 is a cross-sectional view of a 4-rus transformer 44. FIG. /pulse transformer 4
4 is the primary winding 76, the secondary winding 80, and the connector 1
Terminal 104 for electrical connection with 06 (Fig. 5)
have.

Terminal post 108 is post 1 of spark plug 102
10 and the transformer post 105.

The bottom of post 108 mates with plug post 110;
There is a grip socket 107 for this purpose. Gorm fist boots 11
2 is coupled to the outer ceramic surface of spark plug 102 and supports 7 mils transformer 44.Plastic body 109 is fitted with pulse transformer 44.
I support it.

A shield 86 surrounds the pulse transformer 44, and one end of the shield serves as a leg 114 for holding the spark plug 102.

Figures 7 and 8 show the microprocessor-3 at various phases of ignition operation for one of the four cylinders.
The output control signal from 2 is shown. FIG. 7 shows a series of pulse trains generated to initiate ignition of the air/fuel mixture in the cylinder before top dead center. Square wave pulse 116 represents the control signal output from microprocessor 32 along one of lines 56-62. This signal is generated by increasing the pulse transformer 44 (41st order/secondary voltage with respect to time) to generate a sawtooth wave pulse 118.
Like,. Pulse 118 represents the voltage at the spark plug gap. The secondary voltage, which is the pulse 118, increases to the point of discharge, and after discharge, decreases as it moves to the arc phase and glow phase. The waveform of pulse 116 is determined by microprocessor 32 by adjusting the pulse width 120 and pulse period 122 magnitude.

According to a typical experimental example of the pulse transformer 44, the time during which the primary current flows is shorter than 6 μs. When a breakdown occurs, it is detected by loop 92 across ferrite bead 90 and switching transistor 64 turns off the primary current. Then the primary current is clamped
It flows through diode 72 and continues to flow for up to 60 μs. Using the output from loop 92, the ignition interval can be kept short at 40-60 μs. This quick response allows for multiple ignitions, such as 7 pulses. As mentioned above, such multiple ignitions allow the use of more lean fuel mixtures. The inventor has discovered that for one engine, if the pulse group 45 period is 100 μs or less, the heating ratio can be made leaner.

By monitoring the pulse width of the control signal 116,
A measurement of breakdown voltage is made. A dirty plug or pre-ignition will result in a low breakdown voltage, whereas an open circuit will result in a very high breakdown voltage. Therefore, by measuring the breakdown voltage of pulse 20 in FIG. 3, the abnormal ignition condition can be detected.

During the next phase of spark plug activation, after the crankshaft is approximately 5° past top dead center, the signal is
Sent to J Luz Trans 44. At this point in the cycle, autoignition is not inherently present and this signal is provided to sense cylinder pressure before autoignition occurs. FIG. 8 shows the signals from the microprocessor-32,
It is similar to FIG. 7 in that the signal indicates the voltage applied across the spark plug gap at 46. A square wave pulse 124 produces /milk 22 as an interrogation signal. The control signal 124 disappears until the high frequency current is detected at the ferrite bead 90. Due to the rising curve nature of the sawtooth/pulse 22, the duration IvI of the square wave pulse 124 is a function of breakdown voltage.

That is, the phase difference between the tip of pulse 124 and the onset of breakdown is related to breakdown voltage and cylinder conditions:
. If the cylinder pressure is higher than the average value (or if the cylinder temperature is lower than the average value), the pulse 22 must rise to a higher voltage value, as shown by dashed line 128, before discharge occurs. Conversely, if the cylinder pressure is lower than the average value or if the cylinder temperature is higher than the average value, this will be detected by a shortening of the pulse width of the pulses 22° 124.

In the last phase, the "hover" phase, a series of square wave control signals 130 are output from the microprocessor 32;
A corresponding sawtooth pulse train 24 is generated. As mentioned above, this hover voltage is used for automatic ignition detection.

If the cylinder pressure is normal without autoignition, the maximum hover voltage across the plug gap is sufficient to cause a discharge, and when autoignition occurs, rapid fluctuations in pressure and temperature within the cylinder are isolated. Since the breakdown voltage is momentarily reduced, a discharge occurs, which is detected by the ferrite bead 90. This discharge is then used to retard spark timing.

As previously discussed, interrogation/pulse 22 is used to calibrate the appropriate hover voltage value of pulse 24. therefore,
When the cylinder operates normally under higher than average pressure, the maximum value of the hover voltage increases, allowing pressure fluctuations caused by auto-ignition to be detected. vice versa,
If the normal pressure is below average, the hover voltage 24 will be at a low value to prevent false white ignition indications occurring during normal ignition operation. For proofreading 1. A Lus 124 and Pulse]
A pulse width ratio of 30 is used. The higher the breakdown voltage in the interrogation/pulse, the higher the value of */'Wi pressure 24. FIG. 8 shows that when the pulse width is increased, such as pulse 126, the lengthened control signal 132 results in a higher hover voltage 134. During the hopper phase, during normal combustion without discharge, the voltage across the plug gap gradually disappears like the pulse train 24 shown in FIG. Keypad inputs are provided to adjust for the variations made in this routine. block 1
At 40, it is determined whether the cylinders are synchronized so that a fire command is appropriately output from the engine timing transducer 34. 1, block 140
It also detects whether the engine is running. block 142
At step 144, it is determined whether the engine has stopped, and the engine speed is measured. 100 OR of block 144
The value PM is an example of a low rotational speed at which the interrogation/hover signal ends, and automatic ignition does not occur at this rotational speed. Then, block 148 ends the application of the hover voltage at a position 35 degrees after top dead center.

i10 Figure i1: Pulse star of pulse timer in microprocessor-32 and delay control routine 15
It shows 0. Decide on the Koreke pulse width of 120, ignite,
Q. During the hover cycle, the microprocessor
1 for control pulses sent from 32 to pulse transformer 44; (Starts a delay timer that determines the pulse period 122.

Figure 11 shows the width 120 and period 122 of the Hoper phase pulse.
A pulse control routine 154 for determining -50- is shown.

Regarding the input from the engine timing transducer 34: 1. The pulse width and delay timers are started as in blocks 156 and 158, respectively. Block 160 calibrates at 35 degrees after top dead center and is input to block 148 of FIG.

FIG. 12 shows a pulse width routine 162 that is started under software control and stopped by software or an external high frequency current signal. 6 rus timer is shown.

In this routine, the pulse width of the interrogation pulse is set to block 16.
4 is used to determine the hover pulse width.

FIG. 13 shows a false flame hover phase control routine 172f, which includes two blocks 174 and 176, each relating the false flame phase to the hoover phase.

For each block, a pulse timer and a delay timer are started to determine the appropriate pulse width and pulse period.

Although the above description has been made of preferred embodiments of the invention, the invention can be modified without departing from its scope.

[Brief explanation of drawings]

Figure 1 is a characteristic graph of discharge voltage in a spark plug, Figure 2 is a characteristic graph of dielectric breakdown current, and Figure 3 is a characteristic graph of discharge voltage in a spark plug.
The figure shows a graph of cylinder pressure (upper figure) and pulse voltage (lower figure) as a function of crankshaft position, Figure 4 is a block diagram of the ignition system of the present invention, and Figure 5 shows a detailed diagram of the pulse transformer and driver. Circuit diagram, Figure 6 shows /Pulse
Cross-sectional view of the transformer. Figure 7 shows the control signal, secondary voltage, and high-frequency current each/Mils sequence for multiple discharge cycles. Figure 8 shows the 4-Russ waveform of the control signal (upper diagram) and secondary voltage (lower diagram). , and FIGS. 9-13 are flowcharts of each routine controlled by the microprocessor of the ignition system of the present invention. 30... Ignition system: 32... Microprocessor; 44... Pulse transformer; 46... Driver; 82... Spark plug gap; 102...
Spark plug.

Claims (1)

[Claims] (1) A pulse transformer having a primary winding and a secondary winding connected to a spark plug, and a voltage signal applied to the primary winding of the pulse transformer to transform the secondary winding. A driver that induces a high voltage signal in the wire, a controller that gives a control signal to the driver and generates voltage in the secondary winding, and a controller that detects the occurrence of discharge between the spark plug and gives a discharge signal to the controller. 1. An ignition system for an internal combustion engine, comprising: a discharge detection member that controls the operation of a controller; (2) further comprising a timing member that senses the position of the piston and provides a timing signal, the controller controlling a predetermined maximum hover voltage across the spark plug during the cylinder operating cycle after top dead center of the piston; and the hover voltage is applied to a value such that a discharge between the spark plug will occur if there is automatic ignition in the cylinder, but will not occur if normal combustion occurs in the cylinder, and the discharge detection member detects automatic ignition. 2. The ignition system of claim 1, wherein the ignition system detects the presence of non-normal combustion autoignition, which causes pressure and temperature fluctuations within the cylinder after top dead center of the piston, providing a signal indicative of the occurrence of ignition. (3) The cylinder operating cycle is 5° to 3° after top dead center.
3. The ignition system of claim 2, wherein the ignition system has a range of 5 degrees. 4. The ignition system of claim 2, wherein said hover voltage comprises a series of pulses having said predetermined maximum value. (5) The discharge detection member includes a shield that is electrically connected to the spark plug body, a conductor that electrically connects the shield to ground, and a current detector that detects the current in the conductor. 3. The ignition system of claim 2. (6) the controller further provides an interrogation pulse across the spark plug gap to provide a predetermined maximum value of the hover voltage at a position in the piston actuation cycle where auto-ignition does not occur; 3. The spark plug of claim 2, wherein the voltage increases over time until discharge occurs, and the hover voltage is adjusted in response to the pulse width of the interrogation pulse. 7. The ignition system of claim 6, wherein the interrogation pulse is applied near top dead center. 8. The ignition system of claim 2, wherein the controller further delays ignition timing upon detecting automatic ignition and then accelerates ignition timing so that the ignition system operates near the beginning of automatic ignition. (9) The controller causes a series of discharges between the electrodes of the spark plug before top dead center, and the beginning of the pulse train is separated for a time of 100 μs or less, so that multiple spark plug ignitions are caused by a single spark plug. 2. The ignition system of claim 1, wherein the ignition system has an improved flammability limit for the engine's fuel mixture, allowing a leaner air-fuel mixture to be combusted compared to a single ignition. 10. The ignition system of claim 9, wherein the multiple ignitions (discharges) are approximately 70 μs apart. (11) the controller minimizes the duty cycle of pulses of the pulse-transformer by sending a control signal to a driver when a discharge is detected by the discharge detection member;
The ignition system of claim 1. 12. The ignition system of claim 1, wherein the ignition system detects an abnormal condition within the cylinder and causes a breakdown voltage to discharge between the plugs outside of normal values. (13) a timing member that detects piston position and provides a timing signal; an ignition spark plug within the cylinder having electrodes separated by a gap; a power source that provides a voltage across the gap of the spark plug; and a timing signal. control the power supply to apply a predetermined maximum hover voltage across the spark plug gap during the cylinder operating cycle after top dead center, and if the hover voltage is discharged and there is automatic ignition in the cylinder. a controller applied to a value that would not occur if there was normal combustion; An ignition system for an internal combustion engine, characterized in that it detects the presence of automatic ignition, which is not a normal combustion, and which causes pressure and temperature fluctuations in the cylinder after top dead center, comprising a discharge detection member. (14) The cylinder operating cycle is 5° to 5° after top dead center.
14. The ignition system of claim 13, wherein the ignition system is in the range of 35 degrees. 15. The ignition system of claim 13, wherein the hover voltage comprises a series of pulse trains each having a predetermined maximum value. (16) The discharge detection member includes a pulse transformer having a primary winding and a secondary winding connected to a spark plug, a driver that applies a voltage signal to the primary winding of the pulse transformer, and a driver that applies a voltage signal to the primary winding of the pulse transformer, 14. The ignition system of claim 13, further comprising a member for detecting occasional high currents of short duration. (17) The large current detection member includes a shield electrically connected to the spark plug body, a conductor that electrically connects the shield to ground, and a current detector that detects the current in the conductor. 17. The ignition system of claim 16, comprising: (18) The controller further applies an interrogation pulse across the spark plug to provide a predetermined maximum value of hover voltage at a piston actuation cycle position where automatic ignition does not occur, and the voltage of the interrogation pulse causes discharge to occur. 14. The ignition system of claim 13, wherein the hover voltage is adjusted in response to the pulse width of the interrogation pulse. 19. The ignition system of claim 18, wherein the interrogation pulse is applied at top dead center. 20. The ignition system of claim 13, wherein the controller further retards ignition timing upon detecting autoignition and then advances ignition timing so that the ignition system operates near the onset of autoignition. (21) a timing member that detects the piston position and provides a timing signal; an ignition spark plug having an electrode in the cylinder across an air gap; A pulse transformer having a winding and a secondary winding connected to the electrode of the spark plug; a driver for providing a high voltage signal, a ground return conductor connected between one of the spark plug electrodes and ground, and a current detector for sensing the current in the conductor, the spark plug gap having a A discharge detector detects the short-time large current that occurs at the beginning of an arc, and a discharge detector that receives a timing signal and provides a control signal to the driver.
applying a predetermined maximum hover voltage across the spark plug gap during the cylinder operating cycle after top dead center;
The maximum value of the hover voltage is determined such that a discharge occurs if automatic ignition is in the cylinder, but does not occur if there is normal combustion, and is determined by a controller that adjusts the ignition timing according to the output signal of the discharge detector. An ignition system for an internal combustion engine that detects the presence of automatic ignition, which is not a normal combustion, resulting in pressure and temperature fluctuations in the cylinder after top dead center. 22. The ignition system of claim 21, wherein the cylinder operating period is in the range of 5° to 35° after top dead center. 23. The ignition system of claim 21, wherein the hover voltage comprises a series of pulse trains each having a predetermined maximum value. (24) The controller further applies an interrogation pulse across the spark plug to provide a predetermined maximum value of hover voltage at piston actuation cycle positions where automatic ignition does not occur, and the voltage of the interrogation pulse causes discharge to occur. 22. The spark plug of claim 21, wherein the hover voltage increases with time to .theta., and the hover voltage is adjusted in response to the pulse width of the interrogation pulse. 25. The ignition system of claim 24, wherein the interrogation pulse is applied near top dead center. 26. The ignition system of claim 21, wherein the controller further operates near the beginning of automatic ignition by retarding ignition timing if automatic ignition is detected and advancing ignition timing if automatic ignition is not detected. (27) a timing member that detects the piston position and provides a timing signal; an ignition spark plug having electrodes in the cylinder across an air gap; a pulse transformer having a winding, the secondary winding being connected to the spark plug electrode; and a pulse transformer having a secondary winding connected to the spark plug electrode; a driver for providing a high voltage signal, a ground return conductor connected between the spark plug electrode and ground, and a current detector for detecting the current in the conductor to prevent arcing across the spark plug gap. At the beginning of the process, there is a discharge detector that detects a large current that flows for a short period of time,
It receives the timing signal and sends the control signal to the driver,
providing an interrogation control signal at a piston operating cycle position where automatic ignition would not normally occur, the signal increasing the interrogation pulse voltage over time until a discharge occurs, the breakdown voltage at the time of discharge being influenced by pressure and temperature within the cylinder; Measure the phase difference between the tip of the interrogation control signal and the breakdown current, and apply a predetermined maximum hover voltage across the spark plug gap during the cylinder operating cycle after top dead center to The hover voltage is applied to a value that would occur if the discharge was automatic ignition in the cylinder, but would not occur if there was normal combustion.Furthermore, the value of the hover voltage is adjusted according to the phase difference, and the interrogation pulse breakdown voltage is applied. An ignition system for an internal combustion engine, which detects the presence of automatic ignition, which is not a normal combustion, and which causes pressure and temperature fluctuations in the cylinder after top dead center, and a controller that adjusts accordingly. . (28) The cylinder operating cycle is 5° to 35° after top dead center.
28. The ignition system of claim 27, wherein the ignition system is in the range of .degree. 29. The ignition system of claim 27, wherein the hover voltage comprises a series of pulse trains each having a predetermined maximum value. 30. The ignition system of claim 27, wherein the interrogation pulse is applied near top dead center. (31) The controller further sends an ignition control signal in the piston actuation cycle before top dead center to initiate combustion in the cylinder, and instructs automatic ignition to occur if dielectric breakdown is detected during hover. 28. The ignition system of claim 27, wherein the ignition system retards ignition timing. 32. The ignition system of claim 31, wherein the controller further advances ignition timing if automatic ignition is not detected. (33) A pulse transformer connected to the spark plug and having a primary winding and a secondary winding, and sending a pulse voltage to the pulse transformer primary winding to induce a high voltage in the secondary winding. By applying a control signal to the driver and outputting a series of pulses from the secondary winding of the pulse transformer, a series of discharges is caused between the electrodes of the spark plug at intervals of 100 μs or less, and the resulting An ignition system for an internal combustion engine with improved flammability limits for lean air-fuel mixtures, comprising a controller that allows multiple ignitions to combust more lean air-fuel mixtures than single ignitions. 34. The ignition system of claim 33, wherein the multiple ignitions (discharges) occur at approximately 70 ps intervals. (35) The ignition system according to claim 33, further comprising a discharge detection member that detects the occurrence of discharge occurring between the spark plug electrodes, and wherein the controller sends a control signal when detecting discharge. (36) The discharge detection member includes a pulse transformer having a primary winding and a secondary winding connected to a spark plug, a driver that sends a voltage signal to the primary winding of the pulse transformer, 36. The ignition system according to claim 35, further comprising a member for detecting a short period of large current occurring at the beginning of the ignition system. (37) The large current detection member further includes a shield electrically connected to the spark plug body, a conductor that connects the shield to ground, and a current detector that detects the current in the conductor. 37. The ignition system of claim 36. (38) a pulse transformer mounted on the spark plug and having a primary winding connected thereto; applying a voltage pulse to the primary winding of the pulse transformer;
A driver induces a high voltage in the secondary winding, and a control signal is given to the driver to output a series of pulses from the secondary winding of the pulse transformer to generate a series of pulses at intervals of 100 μs or less between the spark plug electrodes. a controller for causing an electric discharge such that the resulting multiple ignitions can burn a more lean air-fuel mixture than a single ignition; and a controller for detecting the occurrence of an electric discharge and providing a signal to the controller;
An ignition system for an internal combustion engine with improved flammability limits for lean air-fuel mixtures, characterized in that the ignition system comprises a discharge detection member for outputting a control signal. (39) The ignition system of claim 38, wherein the interval between the multiple ignitions (discharges) is approximately 70 μs. (40) The large current detection member includes a shield electrically connected to the spark plug body, a conductor that connects the shield to ground, and a current detector that detects the current in the conductor. 39. The ignition system of claim 38. (41) A pulse transformer having a primary winding and a secondary winding connected to the spark plug, and applying a voltage signal to the primary winding of the pulse transformer to cause the secondary winding to be high. It consists of a driver that induces voltage, a controller that provides a control signal to the driver, and a discharge detection member that detects discharge that occurs between the spark plug gap due to the secondary voltage of the pulse transformer, and the controller is An ignition system for an internal combustion engine, characterized in that the ignition system receives a discharge signal from the discharge detection member and shortens a control signal to minimize the pulse duration of the secondary winding. 42. The ignition system of claim 41, wherein the controller minimizes a pulse transformer duty cycle. 43. The ignition system of claim 42, wherein the duty cycle is about 1%. (44) The discharge detection member includes a pulse transformer having a primary winding and a secondary winding connected to a spark plug, a driver that sends a voltage signal to the primary winding of the pulse transformer, 42. The ignition system according to claim 41, further comprising a member for detecting a short period of large current occurring at the beginning of the ignition system. (45) The large current detection member includes a shield electrically connected to the spark plug body, a conductor that connects the shield to earth, and a current detector that detects the current in the conductor. 42. The ignition system of claim 41. (46) A pulse transformer having a primary winding and a secondary winding connected to the spark plug; sending a voltage signal to the primary winding of the pulse transformer and applying a high voltage to the secondary winding; a driver to induce; and sending a control signal to the driver, at the beginning of the control signal,
Increase the spark plug voltage over time until the breakdown voltage is reached and a discharge occurs; normal operation of the engine results in a breakdown voltage within the voltage range, and abnormal conditions within the cylinder result in a voltage outside the voltage range. It consists of a controller that detects the dielectric breakdown voltage, and a discharge detection member that detects the short-time large current that occurs at the beginning of the discharge, and the controller detects the abnormal situation by measuring the dielectric breakdown voltage. An ignition system for an internal combustion engine, which detects abnormal conditions in the cylinder, characterized in that it gives. 47. The ignition system of claim 46, wherein the controller measures the breakdown voltage by detecting the time elapsed between the tip of the control signal and the time of discharge. (48) When the value of the measured dielectric breakdown voltage is lower than the voltage range, it indicates a pre-ignition state;
47. The ignition system of claim 46, wherein a voltage above the range indicates an abnormal ignition condition.