JPS58174157A - Ignition device of internal combustion engine - Google Patents

Abstract

PURPOSE:To prevent heat emission caused by wasteful power consumption in the ignition coil at the time of low speed operation and to hinder voltage drop at the ignition coil at the time of high speed operation, by allowing the angle pulse signal to control the circuit closing angle for the ignition coil with respect to the number of revolutions of the engine. CONSTITUTION:A constant angle pulse signal given by an angle signal generator 1 emits a pulsed waveform. A ripple generator 6 emits a ripple signal b1, whose average level rises as the engine's revolving speed becomes higher. The pulse width of a circuit closing angle control signal C given by a comparator 7 is widened forward and backward from the time point t5 with rising revolving speed of the engine. An AND cicuit 2 emits a pulsed waveform d with logical product signal as ignition signal upon receiving the constant angle pulse signal a and the circuit closing angle control signal C. This pulse width widens with rising revolving speed of the engine. Thereby the circuit closing angle for the ignition coil can be controlled automatically.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to control of the closing angle of an ignition coil in an ignition system for an internal combustion engine.

Conventionally, in so-called point-type ignition systems, or in full-travel type ignition systems that use a fixed-angle signal generator such as a Hall IC system or a metal detection system as an ignition signal generator, the closing angle of the ignition coil depends on the rotational speed of the internal combustion engine. remained constant regardless of For this reason, the above-mentioned conventional device has drawbacks such as heat generation due to wasteful power consumption of the ignition coil when the internal combustion engine rotates at low speed, and a drop in ignition voltage, which is the output of the ignition coil, when the internal combustion engine rotates at high speed.

This invention has been made by focusing on the above points, and provides an ignition device for an internal combustion engine that can easily obtain an ignition signal by controlling the closing angle of the ignition coil with respect to the engine speed from an angle pulse signal. The purpose is to provide

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

In FIG. 1, numeral 1 is an angle signal generator that generates a constant angle pulse signal composed of angular pulses of the maximum closing angle of the ignition coil 4 in accordance with the rotation of the internal combustion engine, and 2 is a constant angle signal from the angle signal generator 1. An AND circuit 3 outputs a logical product signal of a pulse signal and a closing angle control signal from a comparator 7, which will be described later, as an ignition signal, and operates in accordance with an ignition signal from the AND circuit 2 to intermittently energize the ignition coil 4. This is a switch circuit. Further, the ignition coil 4 has a power supply terminal 5 at one end thereof to which electric power is supplied, and is driven by the switch 3 to output an ignition voltage. 6 is a ripple signal generator that receives a constant angle pulse signal from the angle signal generator 1, charges and discharges a capacitor, for example, and generates a ripple signal at a level proportional to the engine speed; 7 is the ripple signal generator 6; The operation of this invention is based on the above-mentioned configuration that outputs a closing angle control signal by comparing the levels of the ripple signal input from the iB! with its own built-in reference voltage.
I will clarify.

First, regarding the basic ignition operation, as the internal combustion engine rotates, the angle signal generator 1 outputs a constant angle pulse signal composed of angle pulses of the maximum closing angle of the ignition coil 4 required when the engine rotates at high speed. do.

This constant angle pulse signal is inputted to a switch circuit 3 after passing through an AND circuit 2. As a result, the switch circuit 3 turns on and off the energization of the ignition coil 40 in response to the constant angle pulse signal. When this current is cut off, the ignition coil 4 outputs an ignition voltage, and as a result, the internal combustion engine is ignited and operated by this ignition voltage.

Next is the control production of the closing angle, which is explained in the second section.
This will be explained with reference to the operation waveform diagram in the figure.

First, the constant angle pulse signal output from the angle signal generator 1 has a pulse waveform as shown in FIG. 2(a). Second
In Figure (a), time t and time t are ignition times at which an ignition voltage is generated at the output of the ignition coil 4, and the angular period from time t1 to time ti is one ignition cycle. Further, the constant angle pulse signal a is at L level during the angular period from time t to time t, and time 1. is at H level in the angle period from time point tit),
The angular period of this H level is constant regardless of the repetition rate of the ignition cycle, that is, regardless of the engine speed.

Next, the ripple generator 6 charges and discharges the capacitor according to the constant angle pulse signal a as described above, and outputs a ripple signal b1 as shown in FIG. 2(b). The level of the output ripple signal b+Fi is changed in synchronization with the constant angle pulse signal a, and the level is changed between a certain time t1 and a time t at the ignition point.
It reaches a maximum at s, and reaches a minimum at time t3 when the constant angle pulse signal a changes from L level to H level. Furthermore, since the charging time constant of the capacitor of the ripple signal generator 6 is set smaller than the discharging time constant, as the repetition period of the constant angle pulse signal a becomes shorter, that is, the engine speed increases. Accordingly, the average level of the ripple signal b1 increases.

Further, the ripple signal S is inputted to a comparator 7 incorporating a reference voltage S. This comparator compares the ripple signal b1 and the reference voltage b2 to determine whether the former is higher than the latter.]
If it is large, a closing angle control signal as shown in FIG. 2(e) is output. That is, in FIG. 2), the closing angle control signal C appears at the output of the comparator 7 during the angular period from time t4 to time t, when the ripple signal b1 is greater than the reference voltage.

As mentioned above, the level of the ripple signal S increases as the engine speed increases, so the time point t4 when the ripple signal S increases to the reference voltage S increases as the engine speed increases. Approaching time t3. On the other hand, the ripple signal S is the reference voltage S.

The time point t, which becomes smaller, moves away from the time point t. That is, the pulse width of the circuit closing angle control signal C output from the comparator 7 widens from time point t as the engine speed increases.

Upon receiving the constant angle pulse signal a and the closing angle control signal C, the AND circuit 2 outputs a pulse waveform as shown in FIG. 2(d) using the AND signal of both the signals a and e as an ignition signal. In FIG. 2(a), the ignition signal d is at time t
4 to time tsK. On the other hand, as described above, time t4 approaches time t when the level of the constant angle pulse signal a changes from L level to H level as the engine speed increases. The pulse width widens as the engine speed increases.

Such an ignition signal d is input to the switch circuit 3, and this switch circuit 3 turns on and off the energization of the ignition coil 40.
As described above, as the engine speed increases, the closing angle of the ignition coil 4 is controlled to increase.

Now, when the engine speed becomes sufficiently high, the level of the ripple signal bl reaches a minimum at time t.

Even if the reference voltage is very large, the comparator 7
Since the circuit closing angle control signal C output from is always at H level 1, the ignition signal d output from the AND circuit 20 has the same waveform as the constant angle pulse signal a.
, the angular period from time t to L level, time 1 . The angular period from time t1 is at H level. Therefore, as in this case, the constant angle pulse signal aO pulse width (time t,
angular period from time t) to the maximum closing angle II of the ignition coil required when the engine is running at high speed! By setting this to , even if the engine speed increases, the closing angle of the ignition coil necessary for this can be automatically controlled to the maximum closing angle.

As mentioned above, in one embodiment of the present invention, the pulse width of the nine constant angle signal a output from the angle signal generator 1 is constant regardless of the engine speed, but if the pulse width is constant regardless of the engine speed, If the pulse width is an angle pulse signal whose pulse width is the ignition coil's 40-year great closing angle, the closing angle of the ignition coil 4 can be set to the maximum closing angle and controlled as in the above-mentioned embodiment, so the angle signal generator 1 The angular pulse signal a' output from the angular pulse signal a' may be, for example, an angular pulse signal having an angular pulse width over a period obtained by subtracting a fixed time from the ignition period.

In addition, the charging/discharging time constant of the capacitor of the ripple signal generator 6 is determined by changing the charging time constant to the discharging time constant as described above.
Although the average level of the ripple signal S is set to increase as the engine speed increases, by setting each value to a relatively small time constant, even when the engine is running at low speed. The ripple signal b1 is the reference voltage.

It can be set to be larger, and the closing angle of the ignition coil 4 required during low-speed rotation can be secured.

Furthermore, as is clear from the above explanation, the closing angle of the ignition coil 4 can be controlled with respect to the engine speed by controlling the reference voltage S with respect to the engine speed. It is also possible to use it in combination with b8 control.

To summarize, the present invention generates a closing angle control signal from a comparator by comparing a ripple signal with a reference voltage, and controls the closing angle of the ignition coil with respect to the engine speed. Compared to conventional ignition systems, it is possible not only to control the closing angle of the ignition coil, but also to automatically set and control the closing angle of the ignition coil to the maximum closing angle required when the engine rotates at high speed. This has the effect of significantly improving the performance of an ignition device for an internal combustion engine, since heat generation in the ignition coil when the engine rotates at low speeds and reduction in ignition output when the engine rotates at high speeds can be prevented.

[Brief explanation of the drawing]

FIG. 1 shows an embodiment of this invention! Lock circuit diagram, 2nd
The figure is a waveform chart showing operation waveforms of the first can opening section. l... Angle signal generator, 2... AND circuit, 3...
-Switch circuit, 4...one ignition coil, 5...power leakage element, 6...ripple signal generator, 7...comparator. In addition, in the drawings, the same reference numerals indicate the same or equivalent parts. Agent Makoto Kuzuno - Figure 2 Procedural amendment (voluntary) 5 Frost 217 Showa Month Day 2 Name of the invention Internal combustion engine ignition device 3 Relationship to the case of the person making the amendment Patent applicant address Chiyoda-ku, Tokyo 2-2-3 Marunouchi Name (601) Mitsubishi Electric Corporation Representative Hitoshi Katayama Department 4, Agent 5 Claims column of the specification to be amended. 6. Contents of the amendment (the claims in the 11th specification are amended as shown in the attached sheet. 7. List of attached documents fl+ Amended patent claims 1 copy or more 2. Claims (1) Ignition that outputs ignition voltage a coil, an angle signal generator that generates a signal of the closing angle of the ignition coil as an angle pulse signal, and a switch circuit that uses the angle/4' pulse signal as an ignition signal to turn the ignition coil on and off. A ripple signal generator for generating a ripple signal between the angle signal generator and the switch circuit; and a ripple signal generator for inputting the ripple signal and comparing it with a reference voltage to close the circuit. A comparator that outputs an angle control signal and an AND circuit that outputs a front ignition signal are provided, and the closing angle of the ignition coil is controlled with respect to the engine speed by the closing angle control signal, and the maximum closing angle is determined. An ignition device for an internal combustion engine, characterized in that the angle pulse signal is set to have a width of 7 pulses. 12) The closing angle control signal is either a ripple signal output from a variable signal generator or a reference voltage of a comparator. 2. The ignition system for an internal combustion engine according to claim 1, which controls one or both of the levels.

Claims (2)

[Claims] (1) An ignition coil that outputs an ignition voltage, an angle signal generator that generates a signal of the closing angle of the ignition coil as an angle pulse signal, and a receiver that uses the angle pulse signal as an ignition signal to intermittently energize the ignition coil. A ripple signal generator for generating a ripple signal between the angle signal generator and the switch circuit, and a ripple signal generator for inputting the ripple signal to a reference voltage. a comparator for comparing and outputting a closing angle control signal is provided via an AND circuit that outputs the ignition signal, and controlling the closing angle of the ignition coil with respect to the engine rotation speed according to the closing angle control signal, An ignition device for an internal combustion engine, characterized in that the maximum closing angle is set in a pulse ring of the angle pulse signal. (2) The closing angle control signal controls the level of either the ripple signal output from the ripple signal generator, the reference voltage of the comparison peak, or both, and the level of the above-mentioned pull signal is adjusted to the above-mentioned level. 2. An ignition system for an internal combustion engine according to claim 1, which comprises increasing the level of the reference voltage.