JPH0668266B2 - Ignition device for internal combustion engine - Google Patents

Description

The present invention relates to an ignition device for an internal combustion engine, which is mainly used in automobiles and which controls an energization time of an ignition coil to an optimum value.

[Conventional technology]

In this type of conventional device, an integrating circuit is provided in one direction in a first section of a signal generator that generates an angle signal in which one cycle of ignition is divided into a first section and a second section in which the angle is constant. After being integrated and integrated in the other direction in the second section, when the integrated value of this integration circuit reaches a predetermined value in the second section, energization of the energization start signal generation circuit is started, and the angle signal is output from the second section. It is considered that the primary current is cut off when a transition to the first section is made to generate a high voltage for ignition on the secondary side of the ignition coil (for example, Japanese Patent Laid-Open No. 50-83643).

[Problems to be solved by the invention]

However, in the conventional device described above, when the internal combustion engine is rapidly accelerated, if the transition from the second section to the first section is accelerated, a signal for turning off the power transistor before the primary current of the ignition coil flows. Therefore, there is a problem that a high voltage for ignition is not generated in the ignition coil.

Furthermore, considering the extremely low speed rotation of the engine, there is a limit to the amount of integration of the integrator circuit in the second section, and therefore the predetermined value in the first section due to the excessively small integration amount (saturation) of the integrator circuit in the second section. There was also a problem that the integration time to accelerates and the energization time becomes excessive.

Therefore, it has been conventionally considered that the engine rotation speed is detected, and when the engine rotation speed is below a predetermined value, the ignition coil energization start time is set to a fixed angular position (for example, Japanese Patent Publication No.
However, there is a problem in that the structure is complicated because it is necessary to separately provide a circuit for detecting the rotation speed.

Therefore, the present invention is capable of generating a sufficient high voltage for ignition in the ignition coil even during rapid acceleration of the internal combustion engine, and is capable of easily enlarging the energization time of the ignition coil during extremely low speed rotation of the engine. The purpose is to prevent it with certainty.

[Means for solving problems]

Therefore, in the first aspect of the invention, the first section and the second section in which the angle is substantially constant during one ignition cycle are provided.
A signal generator that generates an angle signal that is divided into a section and an integration in one direction from the initial value in the second section of the preceding ignition cycle, and the other toward the initial value in the first section of the corresponding ignition cycle. An integration circuit that integrates in the direction of, and an energization start signal generation circuit that generates an energization start signal in synchronization with the time when the integrated value of the integration circuit reaches a first set value in the first section of the ignition cycle, It is turned on at the earlier of the time when the energization start signal is generated in the energization start signal generating circuit and the time when the angle signal of the signal generator transits from the first section to the second section, and the first section is turned on first. The power transistor that turns off when shifting to the section, and the conduction of the primary current starts when the power transistor turns on, and the conduction of the primary current stops when the power transistor turns off, and the high current for ignition to the secondary side. Ignition circuit that generates voltage When the integrated value of the integrator circuit reaches the second set value corresponding to the low speed set rotation speed in the second section of the ignition cycle, the energization start signal generation circuit substantially disables the energization start control of the primary current. In order to achieve this, a technical means called an ignition device for an internal combustion engine equipped with a pre-start control invalidation circuit is adopted.

In the second invention, the first section and the second section in which the angle is substantially constant during one ignition cycle are provided.
A signal generator that generates an angle signal that is divided into a section and an integration in one direction from the initial value in the second section of the preceding ignition cycle, and the other toward the initial value in the first section of the corresponding ignition cycle. An integration circuit that integrates in the direction of, and an energization start signal generation circuit that generates an energization start signal in synchronization with the time when the integrated value of the integration circuit reaches a first set value in the first section of the ignition cycle, It is turned on at the earlier of the time when the energization start signal is generated in the energization start signal generating circuit and the time when the angle signal of the signal generator transits from the first section to the second section, and the first section is turned on first. The power transistor that turns off when shifting to the section, and the conduction of the primary current starts when the power transistor turns on, and the conduction of the primary current stops when the power transistor turns off, and the high current for ignition to the secondary side. Ignition circuit that generates voltage When the integrated value of the integrator circuit reaches the second set value corresponding to the low speed set rotation speed in the second section of the ignition cycle, the integrated value of the integrator circuit becomes the other value in the first section of the next ignition cycle. An integration control circuit for substantially invalidating integration in the direction, and for resetting an integration value of the integration circuit to the initial value in synchronization with the start of energization of the primary current to the ignition coil. An internal combustion engine ignition device including a reset circuit that generates a reset pulse with a short time width is used.

[Action]

According to the first aspect of the invention described above, the angle signal generated by the signal generator divides one ignition cycle into a first section and a second section in which the angle is substantially constant. Then, the integrating circuit integrates in one direction from the initial value in the second section of the immediately preceding ignition cycle, and in the other direction toward the initial value in the first section of the corresponding ignition cycle.

The energization start signal generation circuit generates the energization start signal when the integrated value of the integration circuit reaches the first set value during the first section of one ignition cycle. The power transistor is turned on at the earlier of the time when the energization start signal is generated and the time when the angle signal of the signal generator shifts from the first section to the second section, and the power transistor is turned on from the second section to the first section. At the time of transition, the power transistor is turned on to start the energization of the primary current of the ignition coil, and the power transistor is turned off to interrupt the energization of the primary current to generate a high voltage for ignition on the secondary side. To do. In this way, the energization start signal generation circuit controls the energization start of the ignition coil primary current.

Further, the energization start control invalid circuit of the present invention, when the integral value of the integrator circuit reaches the second set value corresponding to the low speed low rotation speed in the second section of the ignition cycle, the primary current of the energization start signal generation circuit is reduced. Substantially disable the energization start control.

Further, according to the second aspect of the present invention, the integral control circuit, when the integral value of the integral circuit reaches the second set value corresponding to the low speed setting circuit rotation speed in the second section of the ignition cycle, the integration control circuit sets the second ignition cycle of the next ignition cycle. Integrating the integral value of the integrating circuit in the other direction in one section is substantially invalidated, and the primary current conduction start control by the conduction start signal generating circuit is substantially invalidated.
Further, in this case, the reset circuit is the one of the ignition coil.
A reset pulse having a short time width for resetting the integrated value of the integrating circuit to the initial value is generated in synchronization with the start of energization of the next current, and the integrating operation of the integrating circuit is repeated from the second section.

〔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 operation waveform diagram shown in FIG. First, in FIG.
10 is a signal generator, for example, using the Hall effect,
An ignition angle signal is generated which is divided into a first section and a second section whose angle is substantially constant with respect to the rotation angle of the internal combustion engine. Reference numeral 30 is a power transistor, and 20 is a zener diode for withstanding voltage protection of the power transistor 30.

Reference numeral 40 is an ignition coil, and 50 is a battery terminal, which is connected to the positive terminal of the battery via a key switch (not shown). Next, the control circuit will be described. Reference numeral 100 is 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. Reference numeral 200 denotes a charge / discharge control circuit, which includes resistors 201 to 210 and transistors 210 to 216.

Reference numeral 300 denotes an addition / subtraction integration circuit, which includes resistors 301 to 310, a diode 311, a capacitor 312, transistors 313 to 319, and comparison circuit elements 320 and 321.

400 is a monostable, continuous energization blocking circuit, resistors 401 to 41
1,430, diode 412, capacitor 413, transistor
It is composed of 414 to 419 and 431 and comparison circuits 420 and 421.

Reference numeral 500 denotes a constant voltage and output amplifier circuit, which includes resistors 501 to 505, a zener diode 506, and transistors 507 to 509.

Next, the operation of the above configuration will be described. In FIG. 2, the left column shows the case where the engine speed is sufficiently high, the middle column shows the case where the engine speed is extremely low, for example, when starting, and the right column shows the engine stopped with the key switch turned on. Indicate the case. Further, in FIG. 2, (a) to (i)
The respective waveforms shown in Fig. 1 are the waveforms of the respective parts denoted by the same reference numerals in Fig. 1. First, the left column of FIG. 2 will be described.

First, a certain voltage is charged in the capacitor 312 while the angle signal of the signal generator 10, which is the second section of the ignition cycle between the times t _{0 and} t ₁ , is high level. Here, when the angle signal of the signal generator 10 changes from the high level to the low level at time t ₁ , the transistor 106 is turned off, the transistor 215 is turned on, and the current mirror circuit formed by the transistors 313 and 314 and the resistor 30 are connected until then.
The current determined by 2 stops the charging of the capacitor 312, which has been performed via the diode 311 and the resistor 301. At the same time, by turning on the transistor 107, the transistor 3
19 is turned off, and the current mirror circuit of the transistors 317 and 318 causes a current equal to a current flowing through the resistor 305 from the power source of the resistor 305 (referred to as V _CC described later) to pass through the transistor 317 of the charge of the capacitor 312. The time subtraction integration is started, and as a result, the terminal voltage (waveform) of the capacitor 312 linearly decreases while the angle of the signal generator 10, which is the first section of the relevant ignition cycle, is low.

Then, at time t ₂ , that is, at the time when the voltage of the capacitor 312 drops to the first comparison voltage: VT ₁ determined by the ratio of the resistor 306 and the resistor 307, the output (waveform) of the comparison circuit block 320 becomes high level and the transistor 320 212 turns on, transistor 213
Turns off.

At this time, since the output (waveform) of the comparison circuit block 420 is still low level, the common collector waveform () becomes high level because the transistor 214 is off, and the transistor 315 turns on to charge the capacitor 312. Rapidly discharges to the initial value (OV).

Further, when the transistor 212 is turned on, the transistor 414 is turned on.
When the power is turned off, the capacitor 413 is charged from V _CC via the resistors 402 and 403, and at the same time, the transistor 213 is turned off, the transistor 415 is turned on, and the transistor 416
Is turned off, and the capacitor 413 is also charged through the resistor 406 and the diode 412.

Therefore, the terminal voltage (waveform) of the capacitor 413 rises rapidly. In addition, turning on the transistor 212 turns off the transistor 419.

Then, at time t _3, when the terminal voltage of the capacitor 413 reaches the _third comparison voltage: VT ₃ determined by the ratio of the resistors 407 and 408 to the resistor 409, the output of the comparison circuit element 420 (
Waveform) goes high, turning on transistor 214,
The reset pulse in FIG. 2 (h) disappears.

At the same time, since the transistor 431 turns on and the transistor 418 turns off, the transistor 508 turns on, the transistor 509 turns off, the power transistor 30 turns on, and the energization of the primary coil of the ignition coil 40 starts.

Further, when the transistor 214 is turned on, the transistor 315 is turned on.
Is turned off to close the rapid discharge circuit of the capacitor 312, the transistor 415 is turned off, the transistor 416 is turned on, and the charging of the capacitor 413 via the resistor 406 is stopped. Become loose. At this time, transistor 216 is off, but transistor 215 is on, so capacitor 312
Charging does not start.

Then, at time t _4, when the angle signal (waveform) of the signal generator 10 becomes high level, the transistor 106 is turned on and the transistor 215 is turned off, so that charging of the capacitor 312 via the resistor 301 is started. To be done.

Then, when the output of the signal generator 10 becomes low level again at time t ₅ , the transistor 211 turns off, the transistor 419 turns on, the power transistor 30 turns off, and the primary coil of the ignition coil 40 is energized. Is cut off, and a high voltage for ignition is induced on the secondary side.

Next, the middle column of FIG. 2 will be described. When the engine rotation speed is low, as in the case where the engine is being started or immediately after the engine is started, the ignition cycle becomes longer, so the second section of the ignition cycle also becomes longer.
The charging voltage of the capacitor 312 rises. As a result, when the terminal voltage of the capacitor 312 reaches the _second comparison voltage VT ₂ determined by the resistors 308 and 309, the output of the comparison circuit element 321 becomes low level, and as a result, the transistor 316 turns on. As a result, the capacitor 312 is rapidly charged via the resistor 304. Therefore, even if the ignition cycle shifts from the section shown in FIG. 2 to the first section, the charging current through the resistor 304 is larger than the discharging current through the transistor 317, so that the time subtraction integration of the capacitor 312 is performed. Not done Therefore, the terminal voltage of the capacitor 312 does not fall below the first comparison voltage VT ₁ in the first section. Then, when the transistor 315 is turned on again at the time of shifting from the first section to the second section of the ignition cycle, the charge of the capacitor 312 rapidly increases to the initial value (OV) during the period of the reset pulse (waveform in FIG. 2). ) Is discharged. Then, when the output of the comparison circuit element 420 becomes high level in order to extinguish the reset pulse, the transistor 418 turns off, the power transistor 30 turns on, and the ignition coil 40
Energization is started.

Further, the output of the comparison circuit element 321 becomes high level by discharging the electric charge of the capacitor 312 to the initial value,
As a result, transistor 316 turns off and capacitor 312
Is no longer rapidly discharged.

Next, the right column of FIG. 2 will be briefly described. When the key switch is turned on, the engine stops and the angle signal of the signal generator 10 keeps high level.
When the 211 remains on, or the signal generator 10
When the angle signal of becomes low level, the electric charge of the capacitor 312 is discharged to 0, the comparison circuit element 320 remains at high level, and the transistor 212 remains on, the transistor 419 turns off. It will remain.

As a result, the terminal voltage of the capacitor 413 continues to rise, and the fourth comparison voltage: VT determined by the ratio of the resistors 407 and 408, 409 set to a value sufficiently larger than the _third comparison voltage VT3.
_When the voltage of the capacitor 413 reaches ₄ , the output (waveform) of the comparison circuit element 421 becomes high level, the transistor 417 is turned on, and continuity of conduction of the power transistor 30 is blocked.

Next, the characteristic of the energization angle: θ with respect to the change of the engine speed: N will be quantitatively described. First, the principle of energization angle control will be described with reference to FIG. First, (a) is a signal generator
10 is an angle signal waveform, and (b) is an addition / subtraction integration circuit 300
3 is a terminal voltage waveform of the capacitor 312 of FIG. Here, when the ignition cycle at a certain rotation speed is T, the signal generator 10
As for the ratio of the high level part and the low level part of the output of, the high level part is K as shown in the figure. Then, the capacitor 312 is added and integrated (charged) in this high level section, that is, the K · T time.
Then, subtraction integration (discharge) is performed in the remaining (TK) section, and when the subtraction integration value reaches a predetermined value: VT ₁ , energization to the ignition coil 40 is started, and the signal generator 10 When the energization is stopped at the time of the fall of the angle signal 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 as follows.

If the ratio at the time of subtractive integration is made equal to K with respect to the ratio at the time of additive integration, the additive integrated amount: V _C in the steady state is subtractively integrated so that it becomes exactly 0 in the next ignition cycle: T section, and the predetermined value Energization time started at: VT ₁ : T _ON can obtain a constant value regardless of the magnitude of V _C accompanying the rotation change. In short, the energization time characteristic changes depending on how much the ratio of subtraction integration to addition integration is set.

For example, considering the case where the subtraction integration ratio is set to be slightly larger as shown in FIG. 4, the T ₁ portion where the time is constant with respect to the engine speed and the time is inversely proportional to the engine speed, It is divided into the T ₂ part with a constant angle, and the T ₂ part increases as the engine speed decreases.Therefore, the energization time in the low-speed rotation range, which is likely to cause insufficient energization time during acceleration of the internal combustion engine, is ideal. It can be set to a large number for the energization angle characteristic.

In addition, when the output of the signal generator 10 changes from the low level to the high level before the discharge voltage of the capacitor reaches the first comparison voltage during the rapid acceleration of the internal combustion engine, the transistor 21
1 is turned on to turn off the transistor 419 and the transistor 418 is turned off after the reset pulse to turn on the power transistor 30 via the transistor 508 and the transistor 509 to start the conduction of the primary current of the ignition coil 40. Let As a result, the primary current energization time is kept at a minimum while the output of the signal generator 10 is at a high level even during rapid acceleration.

Also, as shown in FIG. 2 (h) immediately before the start of energization of the primary current, as shown in FIG. 2 (h), a reset pulse having a short time width is generated and the transistor 315 is momentarily turned on. Is the initial value (0
V) is discharged. Here, since the pulse width of this reset pulse is extremely short, the capacitor 31 in the second section is
2 has almost no effect on charging.

Further, by detecting the charge amount of the capacitor 312 in the second section of the ignition cycle by the comparison circuit element 321 and stopping the subtraction integration of the capacitor 312, the engine speed becomes extremely low, and the addition integration in the second section is performed. Even if the amount is limited by the power supply voltage: V _{CC and} reaches a peak, it is possible to prevent the premature energization start in the first section, so that an excessive energization time at an extremely low speed can be avoided.

FIG. 5 shows an addition / subtraction integration circuit 300 applied to the apparatus shown in FIG.
In another embodiment, a resistor 322 is added in parallel with the transistor 313 to the addition / subtraction integration circuit 300 of the apparatus shown in FIG. 1, and linear addition integration and logarithmic addition integration are used together. The addition and integration of the capacitor 312 is performed, and the same effect can be expected although the configuration is slightly different.

Further, in the structure shown in FIG. 5, a diode 308a is used in place of the resistor 308 in addition to the structure shown in FIG. Change the connection from the emitter side to the collector side, and use this transistor 316
A resistor 310a is connected between the emitter and the base of, and instead of the comparison circuit element 321 composed of a large number of transistors, the emitter is at the connection point of the diode 308a and the resistor 309, the base of the capacitor 312, and the resistor 310. The circuit configuration is simplified by using one transistor 321a whose collectors are connected to each other.

Further, in the above-described first embodiment, the charging voltage of the capacitor 312 is detected and the addition integral larger than the subtraction integral is performed to prevent the energization angle from increasing due to the saturation of the addition integral amount at the extremely low speed. Without being limited to this, as shown in FIG. 6, an integrating element circuit driven by the output of the comparison circuit element 321 is formed in parallel with the transistor 318 on the discharge circuit side instead of the charging circuit including the resistor 304 and the transistor 316. Connect the transistor 316a and compare circuit element
By reversing the input polarity of 321, the subtraction integration itself may be stopped when the charging voltage of the capacitor 312 reaches the second comparison voltage VT ₂ .

Further, in the above-described embodiment, a short time is generated until the integrated value of the second integrator circuit, which is started with the generation of the output signal of the comparison circuit element 320, reaches the first set value having a small value. Ignition coil when the reset pulse disappears
Although the energization start signal for starting energization of 40 is generated, the present invention is not limited to this, and the energization start signal is generated for the comparison circuit element 320 when the integrated value of the first integration circuit reaches a predetermined value. However, the same effect is expected even if the energization of the ignition coil 40 is started earlier than the time when the energization start signal and the angle signal of the signal generator 10 shift from the first section to the second section. It goes without saying that you can do it. In short, it can be easily inferred that the same effect can be expected if the configuration is such that the start of energization of the ignition coil is directly or indirectly determined when the integrated value of the first integrating circuit reaches a predetermined value.

Further, in the above embodiment, the integrating circuit is configured by the analog circuit including the capacitor, but the integrating circuit may be configured by the digital circuit including the counter, and the integrating direction of the integrating circuit is shown in FIG. The positive and negative directions may be reversed.

Further, as the signal generator 10, one that controls the ignition timing by a mechanical advance mechanism or one that electronically controls the ignition timing by using a microcomputer or the like may be used.

〔The invention's effect〕

As described above, according to the first invention, the angle signal of the signal generator changes from the first section to the first section before the energization start signal is generated in the energization start signal generation circuit, such as when the internal combustion engine is rapidly accelerated. In the case of transitioning to the two sections, the transition of this angle signal turns on the power transistor,
Start energizing the next current. As a result, even in the case of rapid acceleration, the angle signal of the signal generator changes
It is possible to secure the minimum amount by keeping it in the section. Moreover, the same integrator circuit used to generate the energization start signal in the first section is used in the second section to obtain an integrated value according to the engine speed, and based on the integrated value. When it is determined to be in an extremely low speed state, the energization start control by the energization start signal generating circuit in the first section is invalidated thereafter, so that the output of the same integrating circuit is selectively used in the first section and the second section. With an extremely simple structure, it is possible to avoid an abnormal energization angle at extremely low speeds.

Further, according to the second aspect of the present invention, it is possible to substantially disable the integration of the integrating circuit to the other side and prevent the energization start signal from being generated.

[Brief description of drawings]

FIG. 1 is an electric circuit diagram showing a first embodiment of the device of the present invention, and FIG. 2 is a waveform diagram of each part used for explaining the operation of the device shown in FIG.
3 and 4 are waveform diagrams of the operating principle of the device of the present invention, and FIGS. 5 and 6 are electric circuit diagrams showing other two embodiments of the addition / subtraction integration circuit used in the device shown in FIG. 10 ...... Signal generator, 30 ...... Power transistor, 40 ...... Ignition coil, 312 ...... Capacitor forming a part of integration circuit, 300 ...... Addition / subtraction integration circuit, 316 ...... Transistor forming integration amount increase circuit , 316a ... Transistor forming integral blocking circuit, 320 ... Comparing circuit element forming part of energization start signal generating circuit, 321, 321a .. Forming part of energization start signal invalidating circuit and integral control circuit Comparator circuit element and transistor, 400 ... Monostable, continuous current blocking circuit including a part of reset circuit.

Claims (4)

[Claims] 1. A signal generator for generating an angle signal for dividing one ignition cycle into a first section and a second section whose angles are substantially constant, and an initial stage in a second section of the preceding ignition cycle. An integration circuit that is integrated in one direction from the value and is integrated in the other direction toward the initial value in the first section of the corresponding ignition cycle; and the integrated value of the integration circuit is first in the first section of the ignition cycle. Of the energization start signal generating circuit for generating the energization start signal in synchronization with the time when the energization start signal is generated in the energization start signal generating circuit and the angle signal of the signal generator in the first section. From the first section to the second section, the power transistor is turned on at a faster time from the second section to the second section, and is turned off when the second section is moved to the first section. 1 by starting and turning off An ignition coil that generates a high voltage for ignition on the secondary side by cutting off energization of the secondary current, and a second set value in which the integrated value of the integrator circuit corresponds to the low speed set rotation speed in the second section of the ignition cycle. And a current-carrying start control invalidating circuit for substantially invalidating the current-carrying start control of the primary current by the current-carrying start signal generating circuit. 2. A signal generator that generates an angle signal that divides one ignition cycle into a first section and a second section whose angle is substantially constant, and an initial stage in the second section of the preceding ignition cycle. An integration circuit that is integrated in one direction from the value and is integrated in the other direction toward the initial value in the first section of the corresponding ignition cycle; and the integrated value of the integration circuit is first in the first section of the ignition cycle. Of the energization start signal generating circuit for generating the energization start signal in synchronization with the time when the energization start signal is generated in the energization start signal generating circuit and the angle signal of the signal generator in the first section. From the first section to the second section, the power transistor is turned on at a faster time from the second section to the second section, and is turned off when the second section is moved to the first section. 1 by starting and turning off An ignition coil that generates a high voltage for ignition on the secondary side by cutting off energization of the secondary current, and a second set value in which the integrated value of the integrator circuit corresponds to the low speed set rotation speed in the second section of the ignition cycle. And an integration control circuit for substantially invalidating integration of the integrated value of the integration circuit in the other direction in the first section of the next ignition cycle; and energizing the ignition coil with a primary current. And a reset circuit for generating a reset pulse having a short time width for resetting the integrated value of the integration circuit to the initial value in synchronization with the start of the ignition device for an internal combustion engine. 3. The integration control circuit, when the integration value of the integration circuit reaches the second set value in the second section of the ignition cycle, the integration control circuit determines the integration amount in the other direction in the first section. The ignition device for an internal combustion engine according to claim 2, further comprising an integration amount increasing circuit for integrating the integration circuit in one direction with a large integration amount. 4. The integration control circuit prevents integration in the other direction in the first section when the integration value of the integration circuit reaches the second set value in the second section of the ignition cycle. The ignition device for an internal combustion engine according to claim 2, further comprising an integration blocking circuit that operates.