JPH0544560B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an ignition device for an internal combustion engine that is mainly used in automobiles and controls the energization time of an ignition coil to an optimum value.

[Conventional technology]

A conventional device of this kind has an integral circuit in one direction in the first section of a signal generator that generates an angle signal that divides one ignition cycle into a first section and a second section where the angle is constant. The integrated value is integrated in the other direction in the second section, and when the integrated value of this integrating circuit reaches the set value in the second section, the energization of the energization start signal generation circuit is started, and the angle signal starts from the second section. 1st
A system has been proposed in which a high voltage for ignition is generated on the secondary side of the ignition coil by cutting off the primary current when transitioning to the section (for example, Japanese Patent Laid-Open No. 83643/1983).

[Problem that the invention seeks to solve]

However, in the conventional system described above, when the internal combustion engine suddenly accelerates, if the angle signal of the signal generator shifts from the second section to the first section before the integral value of the integrating circuit reaches a predetermined value, the ignition coil changes. Since the signal to turn off the power transistor is applied before the primary current flows, not only does the high voltage for ignition not occur in the ignition coil, but the integrated value of the integration circuit remains. Since it will be integrated again in one direction, the next time it is integrated in the other direction, the integrated value will be greater than the actual value, and the point at which this integrated value becomes the set value in the second interval That is, there is a problem in that there is a delay in the timing at which the primary current starts flowing, resulting in a shortage of ignition energy in the next ignition cycle.

Therefore, an object of the present invention is to obtain sufficient ignition energy even during rapid acceleration.

[Means for solving problems]

Therefore, the present invention provides a signal generator that generates an angle signal divided into a first section and a second section in which the angle is substantially constant during one ignition cycle, and an initialization signal in two sections of the previous ignition cycle. is integrated in one direction than the value,
an integrating circuit having a single integrating means that integrates in the other direction toward the initial value in a first section of the corresponding ignition cycle; and an integral value of the integrating circuit is shifted by a predetermined value from the initial value in the first section. an energization start signal generation circuit that generates an energization start signal in synchronization with the point in time when the energization start signal reaches a set value; A power transistor is turned on at the time of transition from the second section to the second section, whichever is faster, and is turned off when the second section is transferred to the first section, and when this power transistor is turned on, the primary current begins to flow. and an ignition coil which, when turned off, cuts off the primary current and generates a high voltage for ignition on the secondary side, and the integration circuit in synchronization with the start of the primary current to the ignition coil. To provide an ignition device for an internal combustion engine, which includes a reset circuit that generates a reset pulse with a short time width for resetting the integral value of the internal combustion engine to an initial value.

Furthermore, the present invention provides the above-mentioned reset circuit, which starts integration when the primary current of the ignition coil starts to flow, and performs a second integration in which the angle signal of the signal generator is reset during the first interval. In order to reset the integral value of the first integrating circuit to the initial value by detecting the time from when the integration of the circuit and the second integrating circuit starts until the integral value reaches the first set value, which is a small value. a first integral value detection circuit that generates a reset pulse with a short time width, and further includes a first integral value detection circuit that generates a reset pulse having a short time width of The present invention provides an ignition device for an internal combustion engine, which includes a second integral value detection circuit for turning off the power transistor when the power transistor is detected.

[Effect]

As a result, in the second section of the previous ignition cycle, the signal generator generates an angle signal that divides one ignition cycle into a first section and two sections in which the angle is substantially constant. The integration circuit is integrated in the direction of
In the first section of the corresponding ignition cycle, integration is performed toward the initial value and in the other direction, and when the integrated value of this integrating circuit reaches a set value shifted by a predetermined value from the initial value in the first section, an energization start signal is issued. A energization start signal is generated in a generation circuit, and the faster of the time when the energization start signal is generated in the energization start signal generation circuit and the time when the angle signal of the signal generator shifts from the first section to the second section. When the power transistor is turned on, the power transistor is turned off when transitioning from the second section to the first section, and when the power transistor is turned on, the primary current of the ignition coil starts to flow, and when it is turned off, the primary current starts flowing through the ignition coil. When the current is cut off and a high voltage for ignition is generated on the secondary side, and when the primary current of the ignition coil is started, the reset circuit resets the integral value of the integrating circuit to the initial value. Generates a reset pulse with a short time width.

Further, the reset circuit is configured to reset one of the ignition coils.
When the next current is started, the second integrating circuit starts integrating, the angle signal of the signal generator resets this second integrating circuit during the first interval, and the second integrating circuit A first integral value detection circuit detects the period from the start of integration until the integral value reaches a first set value having a small value, and resets the integral value of the first integral circuit to the initial value. Generates a short reset pulse. Further, when the second integral value detecting circuit detects that the integral value of the second integrating circuit reaches a second set value that is sufficiently larger than the first set value, the power transistor is turned off.

〔Example〕

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

A first embodiment of the present invention will be described with reference to the circuit diagram shown in FIG. 1 and the operational waveform diagram shown in FIG. 2. First, in FIG. 1, numeral 10 is a signal generator for ignition that utilizes the Hall effect, for example, and is divided into a first section and a second section whose angle is substantially constant with respect to the rotational angle of the internal combustion engine. It generates an angle signal. 30
is a power transistor, and 20 is a Zener diode for voltage protection protection of this power transistor 30.

40 is the ignition coil, 50 is the battery terminal,
It is connected to the positive terminal of the battery via a key switch (not shown). Next, the control circuit will be explained. Reference numeral 100 denotes an input waveform shaping circuit for shaping the angle signal of the signal generator 10, and is composed of resistors 101 to 105 and transistors 106 and 107. 200 is a charge/discharge control circuit, which includes resistors 201 to 210 and transistors 211 to 2.
It consists of 16.

300 is an addition/subtraction/integration circuit, and resistors 301~
306, diode 307, capacitor 308 forming a single calculation integrating means, transistor 309
312 and a comparison circuit element 313.

Reference numeral 400 denotes a monostable, continuous current blocking circuit, which includes resistors 401 to 411, a diode 412, a capacitor 413, transistors 414 to 418, and comparison circuit elements 419 and 420.

500 is a constant voltage, output amplification circuit, and resistor 5
01 to 505, a Zener diode 506, and transistors 507 to 509.

Next, the operation of the above configuration will be explained. In FIG. 2, the left column shows a case where the engine rotation speed is relatively low, the middle column shows a case where it is relatively high, and the right column shows a case where the engine is stopped with the key switch turned on. In addition, the waveforms of each part indicated by a to i in FIG. 2 are the waveforms of the parts indicated by the same reference numerals in FIG. 1. First, the left column of FIG. 2 will be explained.

First, while the angle signal of the signal generator 10 is at a high level, which is the second interval of the ignition cycle before the time t ₀ - t ₁ , the capacitor 308 is exponentially charged with a certain voltage from the initial value of OV. be done. Here, when the angle signal of the signal generator 10 changes from a high level to a low level at time t ₁ , the transistor 106 is turned off and the transistor 215 is turned on. Charging of the capacitor 308 is stopped. At the same time, transistor 107 is turned on, transistor 311 is turned off, and transistor 310 is turned on.
and 312 current mirror circuit, resistor 30
4 power supply (referred to as Vcc, which will be described later), resistor 304
A current equal to the current flowing through the capacitor 308 initiates a time subtractive integration through the transistor 310 of the charge on the capacitor 308 such that the voltage (waveform) at the terminals of the capacitor 308 is the first leg of the corresponding firing period. While the angle signal of the signal generator 10 is at a low level, it decreases linearly.

Then, at time t ₁ , that is, the resistance 305 and the resistance 30 are set values shifted by a predetermined value from the initial value (OV).
When the voltage of the capacitor 308 drops to the first comparison voltage: VT ₁ , which is determined by the ratio of .

At this time, the output (waveform) of the comparator circuit element 419
is still at a low level, so transistor 214
Since is off, its common collector waveform () goes high, turning on transistor 309 and rapidly discharging the charge in capacitor 308 to its initial value (OV).

Further, when the transistor 212 is turned on, the transistor 414 is turned off, and the resistor 41 is connected to the constant voltage power supply.
At the same time, the capacitor 413 is charged through the transistor 2,403, and the transistor 415 is turned on due to the transistor 213 being turned off.
16 is turned off, and the capacitor 413 is also charged via the resistor 406 and diode 412.

Therefore, the terminal voltage (waveform) of capacitor 413 rises rapidly. In addition, the transistor 21
2 turns on the transistor 418, and as a result, the power transistor 30 turns on and energization to the primary coil of the ignition coil 40 begins.

Then, at time _t3 , when the terminal voltage of capacitor 413 reaches the second comparison voltage: _VT2 determined by the ratio of resistors 407, 408 and resistor 409, the output (waveform) of comparison circuit element 419 becomes high. level, the transistor 214 turns on,
The reset pulse of FIG. 2h disappears.

As a result, the transistor 309 is turned off and the rapid discharge circuit of the capacitor 308 is closed, and the transistor 415 is turned off and the transistor 416 is turned on to stop charging the capacitor 413 via the resistor 406. The charging slope of 413 is gradual. At this time, the transistor 216 is off, but since the transistor 215 is on, the capacitor 3
Charging of 08 is not started.

Then, at time t ₄ , the angle signal of the signal generator 10 (
When the voltage reaches a high level, the transistor 106 is turned on and the transistor 215 is turned off, so that charging of the capacitor 308 via the resistor 301 is started.

Then, at time t ₅ again, when the output of the signal generator 10 becomes low level, the transistor 211 is turned off, the transistor 418 is turned on, the power transistor 30 is turned off, and the ignition coil 40 is turned off.
Power to the secondary coil is cut off, and a high voltage for ignition is induced on its secondary side.

Next, the middle column of FIG. 2 will be briefly explained. As the engine speed increases, the amount of charge to the capacitor 308 decreases, so the timing at which the capacitor 308 reaches the first comparison voltage: VT ₁ when it is discharged also becomes earlier, and as a result, the ignition coil 40
energization starts earlier. The characteristics of the energization angle with respect to the engine speed in this case will be discussed quantitatively later, and will therefore be omitted.

Next, the right column of FIG. 2 will be briefly explained. When the key switch is turned on, if the engine stops and the angle signal of the signal generator 10 remains at a high level and the transistor 211 remains on, or if the angle signal of the signal generator 10 remains at a low level. If the charge in the capacitor 308 is discharged to 0, the comparator circuit element 313 remains at a high level, and the transistor 212 remains on, the transistor 41
4 remains off.

As a result, the terminal voltage of the capacitor 413 continues to rise, and the resistors 407 and 408, 408, which are set to a value sufficiently larger than the second comparison voltage _VT2 , continue to rise.
When the voltage of the capacitor 413 reaches the third comparison voltage: VT ₃ determined by the ratio of
Continuation of conduction is prevented.

Next, the characteristics of the energization angle: θ with respect to changes in the engine speed: N will be quantitatively explained. First, the principle of closing angle control will be explained based on FIG. 3.
First, (a) is the angle signal waveform of the signal generator 10,
(b) is a terminal voltage waveform of the capacitor 308 of the addition/subtraction/integration circuit 300. Here, when the ignition period at a certain rotational speed is T, the ratio of the high level part to the low level part of the output of the signal generator 10 is assumed to be K, where the high level part is as shown in the figure. Then, the capacitor 308 is added and integrated (charged) in this high level interval, that is, time K·T, using a specified function of time, and the remaining (T
-K/T) section, simple subtraction integration (discharge) of time is performed, and when the subtraction integration value reaches a predetermined value: VT, energization to the ignition coil 40 is started, and the angle signal of the signal generator 10 is If the energization is stopped at the time of falling from the high level to the low level and the section indicated by T _ON in the figure is the energization time to the ignition coil 40, the energization angle is calculated as follows.

Conditions...C: Capacity of capacitor 308, K: Data ratio of signal generator, R ₃₀₁ : Series combined resistance value of resistors 301 and 302, R ₃₀₄ : Resistance value of resistor 304, V _CC : Power supply of resistors 301 and 304 Voltage, Vc: Charging voltage of capacitor 308, Calculated base-emitter voltage of transistor 312: V _BE ≈0. Also, diode 30
Forward voltage effect of No. 7: V _F ≈0.

Calculating based on the above, Vc=V _CC・[1-exp(-K・T/R ₃₀₁ ×C)] The discharge current of capacitor 308: Ics is Ics=V _CC /R ₃₀₄ T _ON =T-Tc= T-(V _c -V _T )・C/Ics = T-V _C ×C/Ics+V _T・C/Ics = T-V _C ×C×R ₃₀₄ /V _CC +V _T ×C×R ₃₀₄ /V _CC =T-V _CC ×C×R ₃₀₄ /V _CC [1-exp(-K・T/R ₃₀₁ ×C)]+V _T ×C×R ₃₀₄
/V _CC T _ON =T-C・R ₃₀₄ [1-exp(-K・T/R ₃₀₁ ×C)] +V _T ×C×R ₃₀₄ /V _CC where, V _T =0.2

Claims (1)

[Scope of Claims] 1. A first beam whose angle is substantially constant during one ignition cycle.
A signal generator that generates angle signals separated into an interval and a second interval, and an angle signal that is integrated in one direction from the initial value in the second interval of the previous ignition cycle, and is integrated in one direction in the first interval of the corresponding ignition cycle. an integrating circuit having a single arithmetic integrating means that integrates in the other direction toward the initial value; and an integral value of the integrating circuit reaches a set value shifted by a predetermined value from the initial value in the first interval. An energization start signal generation circuit that generates an energization start signal in synchronization with a time point, and when the energization start signal is generated in this energization start signal generation circuit and the angle signal of the signal generator shifts from a first period to a second period. A power transistor is turned on at the faster time of the transition from the second section to the first section, and is turned off when the transition from the second section to the first section occurs.When this power transistor is turned on, the primary current begins to flow, and the power transistor is turned off. The primary current is cut off by the ignition coil, which generates a high voltage for ignition on the secondary side.
An ignition device for an internal combustion engine, comprising: a reset circuit that generates a reset pulse with a short duration for resetting the integral value of the integrating circuit to the initial value in synchronization with the start of the next current supply. 2. The ignition system for an internal combustion engine according to claim 1, wherein the integral value in the second section of the integral circuit changes exponentially. 3. The energization start signal of the energization start signal generation circuit is generated immediately when the integral value of the integration circuit reaches the set value in the first interval, and the reset pulse of the reset circuit is generated immediately after the generation of the energization start signal. An ignition device for an internal combustion engine according to claim 1, which occurs simultaneously. 4. The reset pulse of the reset circuit is generated immediately when the integrated value of the integration circuit reaches the set value in the first interval, and the energization start signal of the energization start signal generation circuit is generated as the reset pulse of the reset circuit. The ignition system for an internal combustion engine according to claim 1, which occurs at the time when the ignition device disappears. 5. The first angle is substantially constant during one ignition cycle.
A signal generator that generates an angle signal separated into an interval and a second interval; a first integrator circuit having a single arithmetic integrator that integrates in one direction toward a value and in the other direction; and a setting in which the integrated value of the first integrator circuit is shifted by a predetermined value from the initial value in a first interval. an energization start signal generation circuit that generates an energization start signal in synchronization with the point in time when the energization start signal is reached; It is turned on at the time of transition to the second section, whichever is faster, and from the second section to the first section.
When the power transistor is turned on, the primary current begins to flow, and when it is turned off, the primary current is cut off, and the secondary side receives the ignition high voltage. an ignition coil that generates a voltage; and a second integral that starts integration in synchronization with the start of supply of primary current to the ignition coil, and in which the angle signal of the signal generator is reset during the first interval. circuit, and detects the period from the start of integration of the second integrating circuit until the integral value reaches a first set value having a small value, and resets the integral value of the first integrating circuit to the initial value. A first integral value detection circuit generates a reset pulse with a short time width for the purpose of detecting when the integral value of the second integral circuit reaches a second set value that is sufficiently larger than the first set value. and a second integral value detection circuit for turning off the power transistor. 6. The ignition system for an internal combustion engine according to claim 5, wherein the rate of increase in the integral value of the second integral circuit decreases linearly after reaching the first set value compared to before. . 7. The ignition system for an internal combustion engine according to claim 5, wherein the increase rate of the integral value of the second integral circuit increases as the power supply voltage increases.