JPS5930222Y2 - Ignition system for internal combustion engines - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improved structure of an ignition system for an internal combustion engine, and in particular, it includes a circuit that detects spark energy supplied to a spark plug and controls the ignition coil-next current to maintain a predetermined energy level. The present invention relates to an ignition device for an internal combustion engine that controls the spark energy of a spark plug to a predetermined value by adding the following.

It is known that in conventional ignition systems for internal combustion engines, the duration of the secondary current is controlled to a predetermined value by detecting the duration of the ignition coil secondary current and controlling the primary current. Relatedly, integrate the secondary current to find the area,
It is conceivable to control the area of the secondary current to a predetermined value by controlling the primary current according to this area, but since either method only detects the secondary current, the ignition energy is It cannot be said that it can be detected accurately,
It was difficult to strictly match the engine's requirements with regard to excess or deficiency of spark energy due to fluctuations in secondary voltage, etc.

Therefore, the present invention is designed for use in internal combustion engines that can obtain optimal ignition energy regardless of the type and individual differences of internal combustion engines by detecting arc energy using the primary voltage and secondary current and controlling the primary current. The purpose is to provide an ignition device.

The present invention will be described below with reference to embodiments shown in the drawings.

In the first embodiment shown in FIG. 1, 1 is a battery, 2 is an ignition switch rod 3 is an ignition coil, 3a is its primary winding, and 3b is its secondary winding.

4 is a spark plug, and 6 is a primary current detection resistor that detects the current flowing through the primary winding 3a of the ignition coil 3.

Reference numeral 14 denotes a known ignition signal generation device, which includes, for example, an ignition timing detection device using an electromagnetic pickup or an ignition timing signal generation device using an electronic advance device.

Reference numeral 13 denotes a known energization time (closing angle) control circuit that receives an ignition signal from the ignition signal generator 14 and controls the timing at which the primary winding current flows through the primary winding 3a of the ignition coil 3;
is a power Darlington transistor (which may be a power field effect transistor) which switches the primary winding current on and off.

I is a Zener diode for protecting the power transistor 5 withstand voltage, 12 is a current control circuit for constantizing the peak current value of the primary winding current of the ignition coil 3 to a predetermined current value, and 8 is an ignition coil. 3 is a secondary current detection resistor for detecting the spark current flowing through the secondary winding 3b, and 9 is a capacitor.

The waveform diagrams of the secondary voltage V□, the secondary voltage v2, the secondary current ■2, and the negative current ■1 are shown in FIGS.

Here, the ignition coil energy E2 is E2-fV2・
It is given by l2dt.

Here, since the shaded area provided for ignition energy in the secondary voltage V2 in Figure 2 corresponds to the shaded area in the primary voltage vl in Figure 2a, E2-CfV□・l2dt (C is a constant ).

Therefore, the -order voltage v1 and the secondary current ■2 are multiplied by the multiplier circuit 1.
By inputting 0, a signal basically corresponding to the spark energy can be obtained.

Here, the reason why the secondary voltage V2 is not used is that it is difficult to measure the secondary voltage and the cost of the device increases.

11 integrates the output of the multiplier circuit 10, outputs it as a predetermined level signal, and inputs it to the above-mentioned current value control circuit 12 as an ignition coil-next current correction signal, thereby setting the ignition energy to a predetermined value. From lm1n in Figure 2 d to I
This is a constant current value correction signal output circuit that controls the primary current peak value within a width of max.

Therefore, the above configuration has the advantage that a predetermined amount of ignition energy can be supplied to the spark plug 4 regardless of engine model differences, individual differences, etc., so it is possible to improve the ignitability of the engine and optimize the ignition energy. can.

FIG. 3 shows an embodiment of the detailed configuration of the apparatus shown in FIG. 1, and the configuration and operation thereof will be explained below with reference to FIG.

As an example of the multiplication circuit 10 for multiplying the ignition energy, if a multiplier 110a manufactured by Analog Devices, Inc., product number 4214 is used, its output E.

is human power X□, X2, Yl. For Y2, Eo”
Since the output has the relationship (XI X2 ) (YI Y2), the input
, 104, a divided voltage signal VB' of the power supply voltage (battery voltage) VB, and input Y1 receives the secondary current I2 from the buffer 1.
Input the signal ■2' via 10b, input Y2
is grounded.

As a result, the output Eo of the multiplier 110a becomes E□ oc
(V1'-VB')I2', and if Eo=E2, a voltage signal proportional to the ignition energy can be obtained.

100 is a monostable circuit that is triggered by the fall of the ignition current (secondary current) and turns on the analog switch 109 for a period of time, and the signal (ignition energy signal Eo) when the analog switch 109 is turned on is sent to the buffer 112. The output is integrated into the capacitor 117 via the operational amplifier 1.
The signal 18b compares and amplifies the reference signal from the reference power supply 116, and transmits it to a field effect transistor (FET) 1200 Å gate via a resistor 119c, thereby controlling the negative current to a predetermined ignition energy.

113 is a monostable circuit that outputs a short pulse signal to discharge the charge in the capacitor 117 at the ignition spark point of the ignition timing signal (the beginning of the output of the signal to turn off the power transistor 5), which turns on the analog switch 118a. It is done by doing.

The current value control circuit 12 uses an operational amplifier 128 to convert a primary current signal (a voltage signal generated at the -order current detection resistor 6 to a resistor 124).
, 127, which corresponds to the -order current) and the comparison signal from the FET 120 through the resistors 122, 126, etc., and if the -order current signal becomes larger than the comparison signal, the power transistor 5 The drive transistor 129 is driven to reduce the current applied to the base of the power transistor 50 via the resistor 129b, and the primary current peak value of the ignition coil 3 is made constant to a predetermined value.

The other output terminal of the operational amplifier 128 is connected to the closed angle control circuit 1.
3, and serves as a signal for reducing the constant current time Ts of the primary current signal 1 in FIG. 2d to within a predetermined time.

FIG. 4 shows the waveforms of each part in FIG. 3.

In FIG. 4, a is the ignition signal α, and b is the multiplier 110a.
The ignition energy signals c and c passed through the analog switch 109 are integrated into the capacitor 117, and the held ignition energy signals η and d are corrected to the current value control circuit 12 using the difference signal ξ compared with the reference signal r. It becomes a signal.

e represents the reset signal β of the monostable circuit 113, and f represents the primary current signal of the ignition coil 3.

With the above configuration, the negative current value can be corrected within a predetermined range in order to control the ignition energy to a predetermined value.

In FIG. 3, the Zener diode 125 is an upper limiter of the primary current value, and the divided voltage signal of the resistors 122 and 126 forms a lower limiter.

Further, 121° and 123 are resistors and Zener diodes that constitute a constant voltage circuit, and 106, 107, 108, 114° and 115, and 119a and 119b are resistors.

FIG. 5 shows the main structure of the second embodiment of the present invention.
Engine parameters (cooling water temperature,
A reference signal correction circuit 15 is added to generate a reference signal having a predetermined functional relationship based on engine speed, EGR signal, intake pipe pressure signal, etc., and a simple embodiment thereof is shown in FIG.

Transistors Ql and Q2 form a current mirror circuit, and a comparator 118b is connected to the dividing point γ of one resistor R2 and R3.
Outputs the standard output to.

The switches SW1 to SW3 and the like are turned on and off for simple addition of engine parameters. For example, during EGR, the switch SW1 is closed to increase the reference signal.

Ro is a resistor for hanging the initial reference signal, R4-R6 are summing resistors, and three switches are shown in FIG. 6, or more or less switches may be used.

The Zener diode ZD□ and the resistor R1 are a constant voltage circuit for creating a reference voltage.

FIG. 7 shows a third embodiment of the present invention, in which the signal corresponding to the ignition energy from the multiplier circuit 10 is input to the energization time correction signal output circuit 11A, and the output of the energization time correction signal output circuit 11A is Ton, min in FIG.
The primary current conduction time is controlled within the range from Ton to max.

FIG. 8 shows a detailed configuration of the device shown in FIG. 7, and the circuit configuration of the energization time correction signal output circuit 11A is almost the same as the constant current value correction signal output circuit 11 shown in FIG.
5a and 115b are resistors.

The output signal of the operational amplifier 118b is transmitted to the voltage dividing resistor 13.
The other end of this voltage dividing resistor 138a is connected to one input terminal of a comparator 131a, and by controlling this terminal voltage, the energization time (closing angle) is controlled and the ignition energy is set to a predetermined value. Control to value.

Next, the closing angle control circuit 13 will be described in detail.

The alternating current signal a shown in FIG.
A voltage proportional to the rotational speed is generated in the capacitor 34a via 38c.

On the other hand, the comparator 131b outputs the signal S already shown in FIG.
Give positive feedback to b.

Then, at that monostable time To, the transistor 30b
conducts through the capacitor 134b through the resistor 138e.
is charged, and the potential d of this capacitor 34b is increased as shown by the solid line in FIG. 9d.

Next, after the monostable time To, the transistor 30b becomes non-conductive, so the resistor 138d,) the transistor 130g,
A speed-dependent discharge of a capacitor 134b takes place via 130a, 130c, 130e, 130d.

Then, the voltage of the capacitor 134b changes to the resistors 138a, 1
Potential at the voltage dividing point of 38b (voltage e shown by the broken line in Figure 9d)
When the voltage is below, a voltage f as shown in FIG.
The charge in the capacitor 134b is quickly discharged via the capacitor 30f.

The power transistor 5 is driven by the output signal of the AND circuit 133 shown in FIG.

Here, the potential e at the voltage dividing point of the resistors 138a and 138b is controlled via the resistor 138a by the output signal k shown in FIG. spark energy can be controlled.

Further, since the output signal of the comparator 131b shown in FIG. 9 is input to the other input of the OR circuit 132, the comparator 131a
When the pulse width of the output signal f of the comparator 131b becomes narrower than the pulse width of the output signal f of the comparator 131b, this comparator 1
The output signal of 31b is output from the OR circuit 132,
Therefore, at low speed rotation below a predetermined value, the comparator 131
The closing angle of the primary current is controlled at a predetermined duty ratio by the output signal from b.

In addition, since the output signal C shown in FIG. 9C of the monostable multivibrator 131 is input to the other input of the AND circuit 133, the pulse width of the output signal f of the comparator 131a changes during high-speed rotation. When the pulse width becomes wider than the pulse width of the output signal C of the monostable multivibrator 137, the output signal C of the monostable multivibrator 137 is outputted from the AND circuit 133. Therefore, even when the rotation speed is higher than a predetermined value, the monostable multivibrator remains active. 137
The closing angle of the primary current is controlled by the output signal C of the coil 1 so that a coil off time of a certain period To is obtained without fail.

Note that the Zener diode 136b forms a square vine with an upper limit, and the Zener diode 136a forms a constant voltage circuit.

Furthermore, g and h in Fig. 9 represent the primary current Ii of the ignition coil 3.
and the secondary current ■2, and the solid and broken lines in FIG.
shows.

FIG. 10 shows an embodiment of the reference signal correction circuit 15 used in place of the reference power supply 1160.

SW1□. SWl.

is a switch that is turned on and off depending on the engine parameters,
For example, one that detects EGR (exhaust gas recirculation) or one that detects engine cooling water temperature, with resistors R15 and R16.
, R□7. The reference voltage output r is changed by the combination of Rts.

Transistor Q11# Q12. Q13. Q□4 forms a constant voltage power supply.

R11~R14, R19'''R23 are resistors, Q15~Q
18 is a transistor, Q19. Q20 is a diode, Q
2□ is a Zener diode.

In each of the above-mentioned embodiments, the primary current value and energization time were corrected for each ignition, but the correction was corrected every 2 rotations of the engine crankshaft or every n ignition rotations (where n is an arbitrary integer). It may be corrected twice.

Furthermore, if an engine cylinder discrimination circuit is provided, it is also possible to control the ignition energy for each cylinder.

In addition to the reference signal correction circuit 15 that performs analog correction as shown in FIG. 6 or 10,
Correction values corresponding to engine parameters such as intake pipe negative pressure and rotational speed are stored in advance in digital memory, correction values are read from the digital memory according to the engine parameters, and the read correction values are converted from digital to analog. The reference voltage r may also be obtained by

Further, in each of the above-described embodiments, the spark energy calculation circuit is configured by the multiplier circuit 10, but the secondary current, primary voltage, and other engine parameters are converted into digital signals and stored in advance as address inputs. The spark energy may be read from a digital memory, and the read value may be converted into a digital or analog signal to control the primary current in an analog manner.

Further, as shown in FIG. 11, the secondary winding 3 of the ignition coil 3
By inserting a parallel circuit of a light emitting diode D and a resistor R between the secondary current detection resistor 9 and the secondary current detection resistor 9, the ignition state can be monitored by the light emitted from the light emitting diode D.

As described above, in the present invention, the spark energy is calculated by the spark energy calculation circuit from the secondary current detected by the secondary current detection resistor and the primary voltage of the ignition coil, and this spark energy i - [calculated by the circuit The primary current of the ignition coil is controlled by the primary current control circuit so that the spark energy is set in advance according to the spark energy, regardless of the spark plug electrode gap, engine model, individual differences, secondary voltage fluctuations, etc. This has the excellent effect of reducing excessive energy waste while maintaining the desired ignitability in the engine.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a first embodiment of the device of the present invention, and FIG. 2 is a waveform diagram of various parts for explaining the operation of the device shown in FIG. 1.
FIG. 3 is an electric circuit diagram showing the detailed configuration of the device shown in FIG. 1;
Fig. 4 is a waveform diagram of each part to explain the operation of the device shown in Fig. 3, Fig. 5 is a block diagram showing the configuration of main parts of the third embodiment of the device of the present invention, and Fig. 6 is a standard for the device shown in Fig. 5. An electric circuit diagram showing an example of a detailed circuit of the signal correction circuit 15, FIG. 7 is a block diagram showing a third embodiment of the device of the present invention, and FIG. 8 is an electric circuit diagram showing a detailed configuration of the device shown in FIG. Figure 9 is a waveform diagram of each part used to explain the operation of the device shown in Figure 8;
The figure shows a reference signal correction circuit 15 applicable to the device shown in FIG.
FIG. 11 is an electric circuit diagram showing another example of the ignition coil portion applicable to each of the above embodiments. 3... Ignition coil, 4... Spark plug, 5... Power transistor, 6, 11, 12
・・・・・・−Primary current detection resistor, constant current value correction signal output circuit, and current value control circuit that constitute the next current control circuit, 8
...Secondary current detection resistor, 10... Multiplier circuit forming the spark energy calculation circuit, 11A, 13...
. . . - energization time correction circuit, closing angle control circuit, and 14 ignition signal generation device constituting the next current control circuit.

Claims (1)

[Claims for Utility Model Registration] 11. An ignition signal generator that generates an ignition signal that determines the ignition timing, a power transistor that turns on and off in response to the ignition signal from the ignition signal generator, and a power transistor that An ignition coil whose primary current is intermittent by turning on and off, and an ignition coil connected to the secondary side of this ignition coil,
An ignition plug that generates an ignition spark by the high voltage generated on the secondary side, a secondary current detection resistor connected to the secondary side of the ignition coil, a secondary current detected by the secondary current detection resistor, and a secondary current detected by the secondary current detection resistor. a spark energy calculation circuit that calculates spark energy from the primary voltage of the ignition coil; and a primary current control circuit that controls the primary current of the ignition coil to achieve a preset spark energy according to the spark energy calculated by the spark energy circuit. An ignition device for an internal combustion engine, comprising: 2. The primary current control circuit controls the peak value of the primary current to a set value in accordance with a primary current detection resistor connected to the primary side of the ignition coil and the primary current detected by the secondary current detection resistor. and a constant current value correction signal output circuit that corrects the setting value of the current value control circuit so that the spark energy is set in advance according to the spark energy calculated by the spark energy calculation circuit. An ignition device for an internal combustion engine according to claim 1, characterized in that: 3. The ignition device for an internal combustion engine according to claim 2, wherein the correction value of the constant current value correction signal output circuit changes according to engine parameters. 4. The secondary current control circuit includes a closing angle control circuit that controls the closing angle of the power transistor in response to the ignition signal from the ignition signal generating device, and a closing angle control circuit that controls the closing angle of the power transistor in response to the ignition signal from the ignition signal generator, and in response to the spark energy calculated by the spark energy calculation circuit. 1. The ignition for an internal combustion engine according to claim 1, further comprising: an energization time correction signal output circuit for correcting the setting value of the closing angle control circuit so as to achieve a preset spark energy. Device. 5. The ignition device for an internal combustion engine according to claim 4, wherein the correction value of the energization time correction signal output circuit changes according to engine parameters. 6. Utility model registration claims 1 to 5, characterized in that the spark energy calculation circuit comprises a multiplication circuit.
An ignition device for an internal combustion engine according to any one of the items.