JPS5833394B2 - Ignition system for internal combustion engines - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ignition system for an internal combustion engine, and more particularly to an ignition system that always maintains an optimal ignition position regardless of engine conditions.

Conventionally, as shown in Fig. 1, the ignition timing is determined electronically by starting charging a capacitor from a reference angular position M1 of the internal combustion engine, discharging from M2, and determining the ignition timing S when the discharge ends. There is something that says.

At this time, if the charging current is 11 and the discharging current is 12, then 12
The ignition timing can be controlled by keeping il constant and changing il depending on the engine condition.

Incidentally, the timing at which the air-fuel mixture in each cylinder of an internal combustion engine should be ignited must be changed depending on the engine speed and load condition.

That is, for an air-fuel mixture of a constant concentration, the time from ignition until the internal pressure of the cylinder reaches its maximum point due to explosion is constant, so if the rotational speed increases, ignition will occur at a position considerably advanced from top dead center.

In addition, when the rotation speed is low or the vehicle is decelerating, the ignition is performed near top dead center.

In addition, the ignition timing changes depending on the concentration of the air-fuel mixture, which changes depending on atmospheric conditions, etc.; when the mixture is lean, it is delayed, and when it is rich, it is early.

Furthermore, when considering the fuel efficiency of internal combustion engines, the maximum torque point due to the minimum advance angle, so-called M B T (M ini
mumadvance for Be5t Torqu
It is known that it is best to ignite at point e), and it is necessary to change the ignition timing depending on these conditions.

However, in the conventional device described above, the ignition timing is programmed to be average based on the test results of the internal combustion engine, so the ignition timing may deviate significantly from the actual optimum engine cost point. The program point and the actual ignition point differ due to atmospheric conditions, variations in individual engine characteristics, and other factors, making correction difficult in practice.Even if correction is made, the correction factor is Since it depends on various environmental conditions such as rotational speed, intake pressure, temperature, etc., including all of these correction terms has disadvantages such as making the device expensive and complicated, making it impractical due to its construction.

In order to eliminate the above-mentioned drawbacks, the present invention includes a calculation circuit that detects the angular position of the crankshaft of each cylinder of an internal combustion engine and calculates the ignition timing, and detects a reference angle corresponding to a predetermined crank angular position of the internal combustion engine. A reference angle detection circuit, a pressure detection circuit that detects the pressure in the cylinder, and a time difference or angle difference between the reference angle and the maximum pressure angle in the cylinder are determined according to the engine state so that the circumferential angles are equal. By having a configuration that includes an advance/retard detection circuit that corrects the ignition timing and increases the correction speed of the ignition timing as the engine speed increases, and an ignition device that performs ignition,
It is possible to automatically maintain the optimum ignition timing for each engine even when the characteristics of the same type of engine vary, and the engine speed, intake negative pressure, atmospheric condition, etc. that are generally required for internal combustion engine control,
The ignition timing can be automatically converged to the above-mentioned optimum point without making precise corrections based on many parameters such as engine temperature and humidity, and is particularly important when controlling the maximum pressure angle position to the reference angle position. An object of the present invention is to provide an ignition device for an internal combustion engine that can further reduce the hunting phenomenon and quicken the response by increasing the correction speed at high rotational speeds and decreasing the correction speed at low rotational speeds.

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

FIG. 2 shows a block diagram of the present invention, where 1 is 4.
An angular position detection device that detects two angular positions of the crankshaft of a cylinder four-cycle internal combustion engine; 2 is an ignition timing calculation device that calculates an ignition advance angle by starting charging and discharging of a capacitor in response to a signal from the angular position detection device 1; The circuit changes the capacitor charging/discharging current in accordance with engine parameters detected by an engine state detector (not shown), and determines the ignition timing in accordance with the engine parameters.

Reference numeral 3 denotes an ignition device that generates an ignition spark based on a signal from the ignition timing calculation circuit 2.

Reference numeral 4 denotes a reference angle calculation circuit that calculates a reference angle in the same way as the ignition timing calculation circuit 2 based on the angular position detection signal of the angular position detection device 1.

6 is a pressure detection circuit that detects the pressure inside the cylinder of the internal combustion engine;
Reference numeral 5 denotes an advance/retard angle detection circuit that detects the time difference in ignition timing from the output signals of the reference angle calculation circuit 4 and the pressure detection circuit 6.

Next, detailed circuits of the device of the present invention will be explained with reference to FIGS. 3 to 6.

First, in the ignition timing calculation circuit 2 shown in FIG. 3, a reference potential Vref is created by a resistor 2-20 and a 2-21° capacitor 2-22, and is connected to an operational amplifier shown below via a bias resistor.

The ignition timing calculation circuit 2 further includes a NOT circuit 2-
1. Discharge control circuit 2-2, conduction (O
N) Analog switches 2-3, 2-4, 2-9
, charging resistor 2-5, discharging resistor 2-6, reference potential V r
Bias resistor 2-7.2-12 connected to e f
, an input resistor 2, an IL operational amplifier 2-8, 2-13, a capacitor 2-10, and an AND circuit 2-14.

The resistors 2-5, 2-6, 2-11, the capacitor 2-10, and the operational amplifier 2-8 constitute a Miller integration circuit, and when the input voltage is lower than the reference potential Vref, the capacitor 2-10 is charged. When the voltage is higher than ref, the capacitor 2-10 is discharged.

The resistors 2-11, 2-12, and the operational amplifier 2-13 constitute a comparison circuit.

Further, the reference angle calculation circuit 4 shown in FIG. 3 also has a charge control circuit 4-1 and a discharge control circuit 4-
2. Analog switches 4-3, 4-4, 4-9 that conduct (ON) with a signal of "1" level, charging resistor 4-5,
Discharge resistor 4-6, bias resistor 4-7.4-12 connected to reference potential Vref, input resistor 4-11, operational amplifier 4-8.4-13, capacitor 4-10. AND
It is composed of circuits 4-14.

In addition, each of the analog switches 2-3, 2-4, 2
-9, 4-3, 4-4, and 4-9 are preferably constructed from field effect transistors.

In addition, 10 is a key switch, 11 is a battery that serves as a power source,
Ks is a power supply terminal connected to a power supply 11 via a key switch 10.

Further, the charging control circuit 4-1 of the reference angle calculation circuit 4 is connected to the first
As shown in the figure, it is composed of resistors 4-1-1, 4-1-2, and its output terminal B? This is the reference potential Vr due to resistance division.
A constant potential lower than ef is extracted.

Further, the discharge control circuit 4-2 is composed of resistors 4-2-1 and 4-2-2 as shown in FIG. 4, and its output terminal C
By resistor division, a constant potential that is always higher than the reference potential Vref is taken out.

Then, a reference angle Ka indicating a constant angle based on the crank angle is determined by the reference angle calculation circuit 4.

Further, an embodiment of the detailed circuit of the discharge control circuit 2-2 of the angular position detection device 1 and the ignition timing calculation circuit 2 will be described with reference to FIG.

Note that in this embodiment, the engine speed is used as the engine parameter.

In the angular position detector 1, 1-1 are arranged at 4 equal intervals on the outer circumference.
The rotor has several protrusions and is fixed to a distributor shaft (not shown) of a four-cylinder internal combustion engine, and rotates together with the distributor shaft.

Reference numerals 1-2 and 1-3 denote first and second electromagnetic pickups which are arranged at a predetermined angle offset in the circumferential direction of the rotor 1-1, and are opposed to the protrusion of the rotor 1-1.

1-6 and 1-7 are transistors connected to each electromagnetic pickup 1-2.1-3, and 1-4.1-5 is a resistor.

ia and i-9 constitute a flip-flop circuit with NAND circuits, one input of which is the transistor 1-6.
The other input is connected to the collector of transistor 1-1.

The rotor 1-1 rotates once in the direction of the arrow for every two rotations of the crankshaft, and when each protrusion of the rotor 1-1 crosses the electromagnetic pickups 1-2, 1-3, each electromagnetic pickup 1-2. 1-3 falls into the negative figure 9 31. A signal as shown in a2 is generated.

Therefore, each electromagnetic pickup 1-2, 1-3 detects the angular position M12M2 with respect to each cylinder t of the crankshaft.

When a negative signal is generated in each electromagnetic pickup 1-2.1-3, each transistor 1-6.1-1 becomes conductive, and due to the conduction of each transistor 1-6.1-1, the NAND circuit 1 A flip-flop consisting of -8 and 1-9 is activated, and an output as shown in FIG.

The discharge control circuit 2-2 is connected to the angular position detection device 1, and includes capacitors 2-2-1, 2-2-5, and a resistor 2.
-2-2, 2-2-4, 2-2-6, 2-2-9
, 2-2-10, consisting of a transistor 2-2-3, a constant voltage diode 2-2-γ, and a diode 2-2-8, and made of a capacitor 2-2-1 and a resistor 2-2-2. The differential pulse is integrated by capacitor 2-2-5.

When the output pulse of the output terminal 1a of the angular position detection device 1 shown in FIG. -3 is conductive, so
As the engine speed increases, the potential of the capacitor 2-2-5 increases almost linearly, but the potential of the constant voltage diode 2-2
-1 makes the high speed side a constant voltage value, and the low speed side is held to a constant voltage value by the divided potentials of the dividing resistors 2-2-9 and 2-2-10, so the engine speed n of the discharge control circuit 2-2 The output potential A corresponding to the output voltage is as shown in the upper part of FIG.

At this time, the output potential A of the discharge control circuit 2-2 is the reference potential V
It is always higher than ref.

The charge control circuit of the ignition timing calculation circuit 2 is composed of a pressure detection circuit 6 and an advance/retard detection circuit 5 connected to a reference angle detection circuit 4.
The detailed circuit will be described later.

Next, a detailed circuit of the pressure detection circuit 6 will be explained with reference to FIG.

6-1, 6-2, 6-3, and 6-4 are pressure sensor circuits corresponding to each cylinder of the internal combustion engine, and the circuit configuration of the pressure sensor circuits 6-2 to 6-4 shown in the block diagram is based on pressure. It is exactly the same as the sensor circuit 6-1, and each output is connected to the maximum pressure detection circuit 6-5.

Therefore, only the pressure sensor circuit 6-1 will be described as a representative.

Reference numeral 6-1-1 denotes a piezoelectric conversion element, which is installed, for example, together with a spark plug in a plug installation hole of a predetermined cylinder of an internal combustion engine, and inserted into the cylinder.

The output of the piezoelectric transducer 6-1-1 is installed so that the potential tends to increase when the pressure inside the cylinder increases.

6-1-2 and 6-1-3 represent the distributed capacitance of the piezoelectric transducer 6-1-1 and the lead wire, 6-1-4 represents the distributed resistance of the lead wire, and the capacitor 6-1-8 and the reference potential Resistor 6-1-5, resistor 6-1-7.6- connected to Vref
1-9, the operational amplifier 66-1-6 constitutes a charge amplifier, and the output signal 6-13 of this pressure sensor circuit 6-1 is the one in which the output potential decreases when the pressure inside the cylinder increases. It's across the street.

The maximum pressure point detection circuit 6-5 is connected to each pressure sensor circuit 6-1.
~6-4 are connected to resistors 6-4, 5-1, 6-5-
2, 6-5-3, 6-5-4, 6-5-8, 6
-5-6 and an adder consisting of an operational amplifier 6-5-7, a capacitor &-5-9, and a resistor 6-5-10, 6-
5-12, resistor 6- connected to reference potential Vref
5-11, a differential circuit composed of an operational amplifier 6-5-13, resistors 6-5-14, 6-5-18, and a reference potential V
It is composed of a comparator composed of a resistor 6-5-17 connected to ref and an operational amplifier 6-5-16.

And output 6-1 of each pressure sensor circuit 6-1 to 6-4
The signals a to 6-4a are added by an adder to form a waveform as shown in Fig. 9g. This signal is differentiated by a differentiating circuit, and this differentiated output is compared with the reference potential Vref by a comparator. The output of the comparator is at the 1'' level only when the output is lower than the reference potential Vref.

That is, the maximum point Pm of the pressure in the cylinder is when the output of the maximum pressure point detection circuit 6-5 reaches the 1'' level.

Next, the detailed circuit of the advance angle/retard angle detection circuit 5 will be explained with reference to FIG.

The output 4a of the reference angle calculation circuit 4 and the terminal 5b are connected to the terminal 5a.
The output terminal 6-5a of the pressure detection circuit 6 and the output terminal 1b of the angular position detection device 1 are connected to the terminal 5c, respectively.

The terminal 5a is connected to the input terminal of a NOT circuit 5-1, and its output terminal is connected to one input terminal of a NAND circuit 55 via an integrating circuit composed of a resistor 5-2 and a capacitor 5-3.

In addition, the other input terminal of the NAND circuit 5-5 has a terminal 5.
a is directly connected.

Then, a NOT circuit 5-1, a resistor 5-2, a capacitor 5
-3, the NAND circuit 5-5 operates as shown in FIG. 9e when the input signal at the input terminal 5a rises to the "1" level.
It constitutes a monostable circuit that generates a 0'' level output.

Similarly, a NOT circuit 5-6 and a resistor 5- are connected to the terminal 5b.
7. Capacitor 5-8, NANf) circuit 5-9 also constitutes a monostable circuit, and the input signal of terminal 5b is "1".
When the level rises, an output of "0'level" as shown in the ninth diagram is generated.

Also, NANf) circuits 5-10, 5-11, and 5-1
2.5-13 constitute a flip-flop circuit, one input terminal of which is connected to the output terminal of the above-named monostable circuit, and the other input terminal connected to terminal 5c.

Further, the output terminal of the NAND circuit 5-10 for generating the output signal shown in FIG. 9f is connected to the NAND gate 5-16 and EX
The output terminal connected to each input terminal of the CLUS I VEOR circuit 5-14 and generating the output signal shown in FIG. 9i of the NAND gate 5-13 is also connected to the AND circuit 5-15.
and the other input terminal of EXCLUSIVEOR circuit '5-14.

The output terminal of this EXCLUSIVEOR circuit 5-14 is connected to the other input terminal of the NAND circuit 5-16 and the AND circuit 5-15.
6 and the output terminal of the AND circuit 5-15 is connected to each resistor 5-26.
Each transistor 5-17.5-20 through ゜5-27
It is connected to the base.

Then, from each input terminal 5a, 5b, 5c mentioned above, NAN
In the circuit up to the output terminal of D circuit 5-16 and AND circuit 5-15, the time difference between the reference angle signal and the maximum pressure signal is determined, and when the maximum pressure signal occurs later than the reference angle signal, NAND is executed. An O°'' level signal is generated at the output terminal of the circuit 5-16 in accordance with the time difference.

Conversely, when the maximum pressure signal is generated earlier than the reference angle signal, a signal of "1" level is generated at the output terminal of the AND circuit 5-15 in accordance with the time difference.

Each of the following transistors 5-17.5-20, resistors 5-18
, 5-19 , 5-25.5-23, capacitor 5-
21, diode 5-24, constant voltage diode 5-22
The circuit configured as above charges the capacitors 5-21 when one transistor 5-11 is conductive, and discharges the capacitor 5-21 when the other transistor 5-20 is conductive.

Therefore, the charging voltage of this capacitor 5-21 is NAN
When a "0'" level signal is generated in the D circuit 5-16 and when the A
It changes only when a "1" level signal is generated in the ND circuit 5-15, and increases almost linearly depending on the time that a 0" level signal is generated in the NAND circuit 5-16. An upper limit is set by -22, and above that it remains constant.

Also, while the "1" level signal is generated in the AND circuit 5-15, the voltage of the capacitor 5-21 decreases almost linearly, but a lower limit is set by the diode 5-24. Anything beyond that is a constant roar.

Therefore, the charging voltage of the capacitor 5-21 changes linearly only within a certain voltage range.

The output voltage of this capacitor 5-21 is connected from the terminal 5d to the input terminal of the analog switch 2-3 of the ignition timing calculation circuit 2, so as to determine the charging current of the ignition timing calculation circuit 2. be.

The output potential of the advance/retard detection circuit 5 is always lower than the reference potential V r e f.

Further, a tooth number pulse such as a ring gear of an internal combustion engine, which is proportional to the engine rotational speed and whose pulse number is smaller than the number of ignitions, is detected and applied to the input terminal 5Aa with an electromagnetic pickup or the like. is waveform-shaped by the monostable circuit 5A to form a signal corresponding to the tooth number pulse that becomes 1" level for a certain period of time, and then the shaped tooth number pulse is ANDed by the AND circuit 5-is.

Since it is applied to the input of the NAND circuit 5-16, the gates of the AND circuit 5-15 and NAND circuit 5-16 open only when the shaping tooth number pulse proportional to the engine speed is 1' level, and the ignition timing is adjusted. As a result, the higher the engine speed, the greater the amount of correction to the ignition timing.

Next, the operation of the apparatus of the present invention having the above-mentioned structure will be sequentially explained from the principle using both the principle diagram shown in FIG. 1 and the waveform diagram of each part shown in FIG. 9.

First, the calculation principle of the present invention will be explained using the operation diagram shown in FIG.

The angular position M12M2 of the crankshaft of each cylinder is detected, and the ignition timing calculation circuit 2 charges the capacitor with a charging current i1 from the time point <Ml, as shown in b, and stops charging at the time point M2, and at the same time starts discharging. It discharges with a flow i2.

Then, the expected end of discharge is set as the ignition timing.

Here, the angle from Ml to M2 is θa1, the angle during discharge of the capacitor is θ1, the top dead center at the compression stroke path of each cylinder is T, the ignition timing is S, and the angle from M2 to T is θK.

If the angle from S to T, that is, the ignition advance angle, is α, then
Even though the following relationship holds true, the ignition advance angle α can be changed by making the charging current and discharging current of the ignition timing calculation circuit 2 correspond to the parameters of the internal combustion engine.

In addition, in the ignition timing calculation circuit 2, the charging current is kept constant and the discharging current is changed according to the engine parameters, or the discharging current is kept constant and the charging current is changed depending on the engine parameters, or the charging current and the discharging current are changed depending on the engine parameters. By changing the current (or voltage) characteristics of simple engine parameters (e.g. -th linear characteristics),
Advance angle characteristics can be adjusted to meet requirements.

Although the above principle has been described for the ignition timing calculation circuit 2, the calculation method of the reference position detection circuit 4 is also the same.

However, the degree reference angle Ka is always a fixed value.

Next, the operation of the detailed embodiment described above, including the engine operating state, will be explained.

The angular position detecting device 1 emits a rectangular pulse in synchronization with the rotation of the crankshaft of an internal combustion engine (not shown), and has an output terminal 1a having a signal M1 as shown in FIGS. 7a and 9.
It emits an output of "1" level between M2 and M2, and an output of "O" level between M2 and M1, and generates an output of two pulses of two cycles per revolution of the internal combustion engine.

Then, when the angular position detection device 1 reaches the 1''' level, the analog switch 2-3 of the ignition timing calculation circuit 2 is turned on.

At this time, since the output of the NOT circuit 2-1 is at O'' level, the analog switch 2-4 is turned OFF, and the seventh
As shown in Figure d, the output signal of the AND circuit 2-14 is “O”.
Analog switch 2- for capacitor reset in Lebel
9 is OFF, the capacitor 2-10 is set at M from the reference potential Vre f in accordance with the output of the advance/retard detection circuit 5.
From time 1 onward, the battery is charged as shown in FIG. 1 and FIG. 9C.

By charging this capacitor 2-10, the operational amplifier 2-8
Since the output of the comparator becomes higher than the reference potential Vref, the output of the comparison circuit goes to the On level as shown in FIG. 1C.

Next, at time M2, when the signal at the output terminal 1a of the angular position detection device 1 reaches the "Ort" level, the analog switch 2-
3 turns OFF, and at the same time analog switch 2-4 turns OFF.
Therefore, the capacitor 2-10 is connected to the discharge control circuit 2-
Discharging is started as shown in FIGS. 7 and 9C by a discharge current corresponding to the engine speed as shown in the middle column of FIG. 8 of 2.

Then, when the discharge of the capacitor 2-10 is completed, the output of the operational amplifier 2-8 becomes lower than the reference potential Vref, so the output of the comparator circuit is inverted to the "1" level as shown in FIG. 1C. , and the output of the AND circuit 2-14 becomes "Level" as shown in Fig. As shown in Figure C, the reference potential Vref
is kept constant.

The signal of the output terminal 2a of this ignition timing calculation circuit 2 becomes an input to the ignition device 3, and at the time of the rising edge of this signal, the ignition device 3
The ignition spark is emitted by the ignition spark.

Furthermore, considering the reference angle calculation circuit 4, its configuration is almost the same as that of the ignition timing calculation circuit 2, and there is no difference in the calculation method between the two. Charge between M2 and M
The same is true for points 1, 1, 2, and 3.

However, the connection of the charge/discharge control circuits 4-1 and 4-2 is different, and when the output of the output terminal 4a rises to the "1" level, it only serves as a reference position detection point and no ignition spark is generated. .

That is, in the reference angle calculation circuit 4, the charging control circuit 4
Since the output currents of the -1 and the discharge control circuit 4-2 are both constant, a reference angular position signal is always generated at the output terminal 4a at a constant reference angular position regardless of the engine speed.

In addition, pressure sensor circuits 6-1, 6-2, 6-3゜6
The internal pressure signal of each cylinder detected at step -4 is detected at the maximum pressure point detection circuit 6-5 to be at the "1" level at the maximum pressure point, and the output terminal 6- of this maximum pressure point detection circuit 6-5 is detected at the maximum pressure point detection circuit 6-5.
The output generated at the terminal 5a is applied to the input terminal 5b of the advance angle/retard angle detection circuit 5, and the output calculated by the reference angle calculation circuit 4 to be at the "1" level when the reference angle Ka is reached is also applied to the advance angle/retard angle detection circuit 5. It is applied to the input terminal 5a of the retard angle detection circuit 5.

Furthermore, an inverted signal generated at the output terminal 1b of the angular position detection device 1 is applied to the input terminal 5c of the advance angle/retard angle detection circuit 5.

Therefore, when the output of the NAND circuit 5-5 reaches the reference angle Ka, a signal that becomes OII level is generated as shown in FIG. 9e, and when the maximum pressure angle Pm arrives, the output of the NAND circuit 5-5
The output produces an on-level signal as shown in Figure 9.

At this time, since the input signal at the input terminal 5c is at the 1' level, the NAND circuit 510 generates a signal at the 1' level as shown in FIG. 9f, and the NAND circuit 5-13
As shown in FIG. 9i, a signal of "1" level is generated.

The EXC'LUSIVEOR circuit 5-14 generates a signal that becomes "1" level only in the portion where the output signals of the NAND circuits 5-10 and 5-13 differ in phase.

Then, this EXCLUSIVEOR circuit 5-14 (7
) Output and NAND circuit 5-10 (71) NAND the output and the monostable circuit 5A mentioned above to NAND circuit 5-16.
As shown in FIG. 9j, the output of this NAND circuit 5-16 becomes ζ.

Therefore, when the maximum pressure angle Pm reaches later than the reference angle Ka by the output of this NAND circuit 5-16, the transistor 5-11 is turned on by that amount, so that the output terminal 5
The potential of d is increased to advance the ignition timing.

Also, the output of EXCLUSIVEOR circuit 5-14 and N
By ANDing the output of the AND circuit 5-13 and the output of the monostable circuit 5A in the AND circuit 5-15, the output of the AND circuit 5-15 becomes as shown in FIG.

Therefore, when the maximum pressure angle Pm reaches earlier than the reference angle Ka by the output of the AND circuit 5-15, the transistors 5220 are made conductive by that amount to reduce the potential of the output terminal 5d and retard the ignition timing. .

In other words, the advance/retard angle detection circuit 5 detects which of the maximum pressure angle Pm and the reference angle Ka, which changes depending on the operating state of the internal combustion engine, reaches the earliest, and based on the time difference, the charge flow of the ignition timing calculation circuit 2 is detected. When the angle is Prrr-)Ka, the angle is retarded, and when the angle is from Ka→Pm, the angle is advanced as shown by the broken line 9c.

In other words, when there is a large deviation, the angle difference between Pm-I-Ka increases and the amount of correction becomes large, and when the difference between Pm-+Ka is small, the amount of correction is controlled to be small, thereby further reducing the hunting phenomenon caused by correction. It is controlled to be small and responsive.

This control range is limited by the constant voltage diode 5=22 and the diode 5-24, so even if the detection of Pm is uncertain, the ignition timing will not deviate significantly from the block 5m, and smooth ignition will be achieved. Timing control can be performed.

Furthermore, in this embodiment, the discharge side current is changed by the engine speed n, and the ignition timing is changed according to the engine speed.
The advance angle characteristic is the MBT characteristic, which is generally known to have the best fuel efficiency.

In the idle link state at the start, the MBT characteristic causes an increase in rotation, so no advance angle is required. Therefore, as shown in FIG. 2-2-8 limits the minimum discharge current.

As a result, the ignition timing can be determined smoothly and with good fuel efficiency from the low speed (idle link) state of the engine operation to the high speed state.

In the above-described embodiment, the correction based on pressure detection is performed on the charging side, but the correction method may be performed on either the charging side or the discharging side.

In addition, in the above-mentioned embodiment, the engine operation is advanced using MBT characteristics, but in other embodiments, control is performed using an advance angle other than MBT, and as an example, when the engine is decelerated, the angle is retarded from the MBT. Explain the method.

That is, as shown in FIG. 10, the advance angle/retard angle detection circuit 5 forming the charge control circuit of the ignition timing calculation circuit 2 of the above-described embodiment.
An auxiliary charging control circuit 5A is added to the auxiliary charge control circuit 5A.

This auxiliary charging control circuit 5A has an output terminal connected to resistors 5A-1 and 5A-2 and normally to the advance angle/retard angle detection circuit 5.
It consists of a switch 5A-3 that switches and connects the output terminal to a voltage determined by the divided resistance value of resistors 5A-1 and 5A-2 during idle link or deceleration.

Therefore, the ignition timing during idling operation or deceleration is not affected by feedback correction, and the auxiliary charging control circuit 5A.

With respect to the engine rotation determined by the discharge control circuit 2-2, the base advance angle characteristic without correction of the reciprocal characteristic is adopted, and the engine torque is suppressed and deceleration is quickly performed.

FIG. 11 shows an embodiment in which, in addition to the embodiment shown in FIG. 9, two auxiliary discharge control circuits are provided on the discharge control circuit side and are fixed during deceleration or idle link operation.

These two auxiliary discharge control circuits connect resistors 2A-1 and 2A-2, and normally connect the output terminal A to the discharge control circuit 2-2, and divide the resistors 2A-1 and 2A-2 during idle link or deceleration. It consists of switches 2-3 that switch and connect the output terminal A to a voltage determined by the resistance value, and both charge and discharge control circuits of the ignition timing calculation circuit 2 are set to a fixed potential during idling or deceleration, and ignition is performed at a fixed angle. It is something that makes you

Note that the switches 5A-3 and 2A-2 may be, for example, limit switches that are switched depending on the position of the accelerator pedal.

FIG. 12 shows an embodiment in which the reference angle Ka is made variable according to engine parameters.

In this Figure 12, 4A is the resistance 4A-1, 4A-2
, analog switch 4A-3, 4A-4 and NOT
Auxiliary charge control circuit consisting of circuits 4A-5, 4B detects tooth number pulses such as ring gear of internal combustion engine and adjusts the vehicle speed to 40Icm.
This is a known vehicle speed detection circuit that generates an output at the n, tt level at speeds above /h, and its output is connected to an analog switch 4A-4 and a NOT circuit 4A-4, which become conductive when a positive voltage is applied.
5 to the analog switch 4A-3.

The operation is such that when the vehicle speed is below 40/crIl, the potential of the charging control circuit 4-1 appears at the output terminal B,
At 0/z or higher, a DC voltage determined by resistors 4A-1 and 4A-2 appears at output terminal B.

Therefore, the reference angle Ka can be changed stepwise by 1.degree. at the vehicle speed of 40 Icr/l/h.

Although not shown, in the embodiments shown in FIGS. 10 and 11, a vehicle speed detection circuit, an engine rotation speed detection circuit, or a manual switch may be used in place of the switch that is turned on during idling or deceleration. Sometimes the lead angle can be a base program without correction.

In addition, in the above-mentioned embodiment, the ignition timing correction for the engine speed is made faster at high speeds and slower at low speeds to further reduce the hunting phenomenon and speed up the response. Although the circuit 5A is used, if the emitter terminal of the transistor 5-11 shown in FIG. 6 is connected to the output terminal A of the charging control circuit 2-2 shown in FIG. Speed allows the above objectives to be achieved.

In addition, in the embodiment described above, the capacitor 2-10
Although an analog type ignition timing calculation circuit that calculates the ignition timing by charging and discharging is used, it is also possible to use an ignition timing calculation circuit using other methods such as a digital type.

Further, in the above embodiment, the reference angle Ka was detected by calculating the charging and discharging of the capacitor 4-10, but the reference angle Ka may also be detected by attaching a third angle sensor. good.

Further, in the above-described embodiment, the angular position detection device 1 is configured to detect the angular position using an electromagnetic pickup, but a photoelectric type or a point type can be used for detection as well.

Further, in the above embodiment, only the engine speed is used as the engine parameter, but it is of course possible to use a plurality of engine parameters such as intake negative pressure and engine cooling water temperature at the same time.

As described above, in the device of the present invention, the ignition timing is determined by feedback correction based on the internal characteristics of the engine to the electronic advance characteristic due to the engine speed, and in particular, the ignition timing is corrected when controlling the maximum pressure angle to the reference angle position. Since the speed is increased when the engine speed is high and decreased when the engine speed is low, conventionally when correcting various parameters such as atmospheric pressure, temperature, humidity, etc. that are generally required for engine operation, it was necessary to correct each item separately. This required a correction circuit and its accuracy, which necessitated an expensive and complicated device.However, this device detects the internal cylinder pressure of the engine and automatically maintains it at the optimum point, so it requires a particularly strict circuit. Furthermore, the hunting phenomenon that tends to occur with feedback correction of ignition timing can be reduced, and the responsiveness of correction can be improved, making it possible to prevent sudden changes in engine operating conditions such as during acceleration and deceleration. It has excellent effects such as smooth operation at times.

[Brief explanation of the drawing]

Figure 1 is a time chart for explaining the operation of the conventional device;
FIG. 2 is a block diagram showing one embodiment of the device of the present invention, and FIG.
6 to 6 are electrical wiring diagrams each showing an example of a detailed circuit of the device of the present invention, and FIG. 1 is a time chart for explaining the principle operation of the device of the present invention shown in FIGS. 3 to 6.
FIG. 8 is a characteristic diagram of each part to explain the operation of the device of the present invention shown in FIGS. 3 to 6, and FIG. 9 is a time chart to provide a detailed explanation of the operation of the device of the invention shown in FIGS. 3 to 6. ,
FIGS. 10 to 12 are electrical wiring diagrams showing main parts of other embodiments of the device of the present invention. 1... Angle position detection device, 2... Ignition timing calculation circuit, 3... Ignition device, 4...
・Reference angle calculation circuit forming the reference angle detection device, 5...
... Advance angle, retard angle detection circuit, 6... Pressure detection circuit.

Claims (1)

[Scope of Claims] 1. An ignition timing system for an internal combustion engine that electronically adjusts the ignition timing of an internal combustion engine, which comprises the following. (a) An angular position detection device that detects the rotational angular position of the internal combustion engine; (b) A device that is connected to this angular position detection device and that is based on a predetermined program according to an angular position detection signal from this angular position detection device. (C) A pressure detection circuit that detects the pressure in the cylinder of the internal combustion engine and detects the maximum pressure angle; (d) A pressure detection circuit that detects the maximum pressure angle by detecting the pressure in the cylinder of the internal combustion engine; a reference angle detection device for detecting a corresponding reference angle; (e) the pressure detection circuit'; - connected to the reference angle 1 degree detection device and the ignition timing calculation circuit; Alternatively, the ignition timing calculation circuit is controlled according to the negative difference to correct the ignition timing so that the position of the maximum pressure angle becomes equal to the reference PL displacement position, and the correction speed is adjusted to increase the engine speed. Lead angle/retard angle detection circuit to increase.