JPS6328236B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ignition method for an internal combustion engine, and more particularly to an ignition method in which a high voltage is repeatedly or continuously applied to a spark plug for one ignition.

During a cold start of an internal combustion engine (hereinafter referred to as engine), the required voltage for discharging at the spark plug is extremely high. In such a case, starting is extremely difficult if the ignition device's ability to generate high voltage is low, the battery voltage is low, or if carbon is attached to the ignition plug. As a result of unnecessarily operating the starter and continuing cranking, there is a risk that the battery voltage will further drop and the engine will be completely unable to start. A countermeasure to this problem would be to improve the high voltage generation ability of the ignition device, but this is technically difficult. In addition, advancing the ignition timing is effective because it reduces the required voltage, but in the case of restarting, when the battery voltage is high enough, or when starting is easy, pre-ignition may occur and the problem may occur. It's bad.
Further, if carbon is attached to the spark plug, no effect can be expected by itself.

The present invention uses an ignition device that repeatedly or continuously applies high voltage to the spark plug for one ignition, and detects the starter energization time at the time of starting, thereby reducing the difficulty of starting. The system advances the start time of high voltage application when starting is difficult, and the end time of high voltage application remains the same as before.As a result, the required voltage for discharge is reduced. Moreover, if carbon is attached to the spark plug, the carbon attached will be burned by a long discharge from an early stage, thereby making it easier to start the engine.

The present invention will be explained below with reference to embodiments shown in the drawings.
Figure 1 shows the overall configuration. 1 is the signal generating section of the distributor (hereinafter referred to as the distributing signal generating section), which generates multiple series of signals in synchronization with the engine crank angle and determines the next ignition timing. Switching circuit 3
is input. On the other hand, the energization signal of the starter 2 is input to this ignition timing switching circuit. The ignition timing switching circuit 3 switches the ignition timing when the energization time of the starter 2 is longer than a set time. 4 is a high voltage generating circuit which generates an AC continuous voltage of about 30 KV only when the signal from the ignition timing switching circuit 3 is at a high level. 5
is a commonly known high-pressure distribution unit integrated into a distributor. 6 is a spark plug and 4
In the case of a cylinder engine, 4 pieces are required. In the examples, a four-cylinder engine will be described.

The configuration of the disk signal generator 1 is shown in FIGS. 2a and 2b.
As shown in the figure. Reference numeral 10 denotes a first disc having one protrusion 10a at each of four positions around the circumference. The position of this protrusion 10a becomes the ignition end position. 11
The second disc has two protrusions 11a and 11b at four positions around the entire circumference. The angular difference between the protrusions 11a and 11b is a crank angle of 30 degrees. Both the first disc 10 and the second disc 11 are press-fitted into the shaft 12 and fixed. This shaft 12 is integrated with a governor mechanism (not shown) that moves depending on the engine speed. Reference numeral 13 designates a conventionally known power-generating type first magnet detector, and reference numeral 14 designates a second magnet detector, which includes a plate that faces the first and second discs 10 and 11 and is movable by intake pipe pressure. (not shown).

As is clear, the operation is performed by the first magnet detector 13.
generates the position of the protrusion 10a of the first disc 10 (for example, the top dead center TDC position) in a waveform as shown in FIG. 4a. The second magnet detector 14 detects the positions of the protrusions 11a and 11b of the second disc 11 (for example, before top dead center).
BTDC10°) is generated with a waveform as shown in Figure 4c. The waveform signal in Fig. 4a is the continuous ignition end waveform, the _C1 signal in Fig. 4c is the first ignition start position, _C2 is the second ignition start position, and the _C2 signal is the conventional advance angle signal. Corresponds to the position, C ₁ signal is 30 more than C ₂ signal
It is located at a position where the crank angle is advanced. First and second disks 10 and 11 and first and second magnetic detectors 13 and 1
Since the relative position of C.4 moves to an advanced position depending on the engine speed and intake pipe pressure, naturally the _C1 and _C2 signals also move with respect to the crank angle.

The circuit configuration of the ignition timing switching circuit 3 is shown in FIG. The input terminal 31 is connected to the output of the first magnet detector 13 and internally connected to the input of the first shaping circuit 35. The input terminal 32 is connected to the output of the second magnet detector 14 and internally connected to the input of a second shaping circuit 36. The input terminal 33 is connected to the output of the starter 2, and internally connected to the input of an inverter 37 via a resistor. The output of the first shaping circuit 35 is connected to the reset input R of the counter 39 with decoder and the first R-S.
It is connected to the reset input of flip-flop 40. The output of the second shaping circuit 36 is connected to a clock input CL of a counter 39 with a decoder. The output of the inverter 37 is connected to the input of the timer 38 and
It is connected to the reset input of the 2R-S flip-flop 41. The timer 38 starts when the input signal drops from a high level to a low level and generates a pulse of about 100 μS after 1 second. This timer 3
The output of 8 is connected to the set input of the second flip-flop 41. The counter 39 with decoder is
The output "1" is connected to the set input of the first flip-flop 40, and the output "2" is connected to the input of the second analog switch (IC product number CD4016, manufactured by RCA) 43. It has been done. The output of the first R-S flip-flop 40 is connected to a first analog switch (IC product number manufactured by RCA).
It is connected to the input of CD4016)42. The control input of the first analog switch 42 and the second
The control inputs of the analog switches 43 are connected to the output Q of the second R-S flip-flop 41, respectively. The outputs of the first and second analog switches 42 and 43 are commonly connected to an output terminal 34 of the ignition timing switching circuit 3.

To explain its operation with the above configuration, the output signal of the first detector 13 (FIG. 4a) is transferred to the first shaping circuit 3.
5 and outputs the waveform shown in FIG. 4b. Similarly, the output signal of the second detector 14 (FIG. 4c) is shaped by the second shaping circuit 36 to output the waveform shown in FIG. 4d. The high level signals C ₁ and C ₂ of the waveform d in Fig. 4
correspond to two ignition start timings, respectively. Here, signal C ₁ is 30 degrees ahead of signal C ₂ in terms of crank angle. Then, when starter 2 operates,
A high level signal is applied to the input terminal 33 as shown in FIG. 5a. Therefore, the output of the inverter 37 becomes a low level as shown in FIG. 5b, and the timer 38 operates and outputs a high level signal as shown in FIG. 5c after about one second. Further, the counter 39 with a decoder is reset by the pulse shown in FIG. 4b and counts the pulse shown in FIG. 4d as a clock input. When the first pulse, that is, the C ₁ pulse of FIG. 4 d, comes, the pulse of FIG. 4 e is generated at the first output of the counter 39, and the second pulse, that is, the C ₂ pulse of FIG. When the pulse arrives, the pulse shown in FIG. 4f is generated at the second output of the counter 39. Then, the counter 3 is activated by the pulse shown in FIG. 4b.
9 is reset. The first R-S flip-flop 40 is reset by the output of the first shaping circuit 35 and set by the first output of the decoder-equipped counter 39, so that its Q output outputs the waveform shown in FIG. 4g. On the other hand, the second R-S flip-flop 4
Since the output of the inverter 37 is applied to the reset input of 1, and the output of the timer 38 is applied to the set input, its Q output has the waveform shown in FIG. 5d, and its output has the opposite waveform. . 1st
Analog switch 42 and second analog switch 4
3 uses RCA's IC part number CD4016, and in both cases, the input and output are conductive when the control input is high level, and cut off when the control input is low level. Therefore, when the starter 2 operates and this operation continues for more than one second, the first analog switch 42 becomes conductive, and the ignition waveform in which the ignition start timing is advanced as shown in FIG. , in other cases, the second analog switch 43 is conductive as shown in FIG.
The ignition waveform of is output at output 34. This figure 4 f
The ignition waveform is a conventional ignition signal with a normal ignition start timing.

Next, the high voltage generating circuit 4 will be explained using the circuit diagram shown in FIG. The high voltage generation circuit 4 periodically generates a high voltage of opposite phase, and includes an oscillation circuit 63, an inverter 64, AND gates 65, 66, base resistors 67, 68, NPN power transistors 69,
70, diodes 71, 72, and a transformer 73, and power transistors 69, 7
0 performs a push-pull operation. An ignition timing signal from the ignition timing switching circuit 3 is applied to the input terminal 60 . Input terminal 61 is connected to a battery via a key switch. The oscillation circuit 63 is composed of a known astable multivibrator,
Generates a rectangular wave pulse of approximately 5KHz. This rectangular wave pulse is passed through the inverter 64 to the AND gate 65.
is added to the other AND gate 66 as is, and both AND gates 65,
66, pulses having mutually opposite phases are applied. Also
A signal from the ignition timing switching circuit 3 is applied to the AND gates 65 and 66 through an input 60.
The output of the AND gate 65 is connected to the base of a power transistor 69 via a base resistor 67.
The output of AND gate 66 is connected to the base of power transistor 70 via base resistor 68. The collector of power transistor 69 is connected to the primary coil of transformer 73 via diode 71, and the collector of power transistor 70 is connected to the primary coil of transformer 73 via diode 72. The emitters of power transistors 69 and 70 are both grounded.
The transformer 73 has a primary coil 73a with a winding ratio of about 100,
It is composed of a secondary coil 73b, and boosts the voltage generated in the primary coil 73a to
Terminals 73c and 73d of the primary coil 73a are connected to the positive electrodes of diodes 71 and 72, respectively, and the intermediate terminal 73e is connected to the positive electrode of the battery via a key switch. Further, a terminal 73f of the secondary coil 73b is connected to the high voltage distribution section 5.

The operation is only activated when the output signal from the ignition timing switching circuit 3 is at a high level, and the operation is a separately excited push-pull circuit, so a detailed explanation will be omitted, but the output 62 is an AC continuous signal. Generates high voltage.

Next, the overall operation of the above configuration will be explained.

(1) Turn on the key switch to start the engine
Furthermore, when the starter 2 is turned on, an AC high voltage of about 10 KHz is applied to the ignition plug 6 from the ignition start signal shown in Figure 4b to the ignition end signal shown in Figure 4d. The spark generated by this causes a complete explosion in less than 1 second. The ignition start signal at this point is the C ₂ signal, which is approximately 10° BTDC. Also, the end of ignition signal is approximately TDC.

(2) For the above-mentioned starting, if there is a large amount of carbon attached to the ignition plug 6, a large spark will not be generated even if high voltage is applied to the ignition plug 6, so please turn on the starter 2 before turning on. It cannot be completely detonated within 1 second. At this time, as the ignition start signal
Since the C ₁ signal is adopted, the ignition plug 6 is
High voltage continues to be applied from BTDC40° to TDC. Then, the attached carbon is burned away by the initial spark, and the second half becomes a large spark, which can lead to a complete explosion. When a complete explosion is reached, the power supply to the starter 2 is stopped, so the C ₂ signal is again used as the ignition start signal.

(3) At the time of starting, if the battery voltage is lowered, the voltage generated by the high voltage generation circuit 4 will be lowered, and for example, the original 30KV will drop to 20KV. If this happens, it will be difficult to discharge at BTDC10°, which is a high pressure, and a complete explosion will not occur. At this time, when 1 second has passed after turning on the starter 2, the high voltage 20KV is applied to the ignition plug 6 at low pressure BTDC 40°.
is applied, so discharge can be easily started. The resulting spark causes a complete explosion.

(4) When starting at extremely low temperatures (below -20°C), the required voltage to generate a spark becomes extremely large, reaching as much as 35KV at BTDC10°, for example. At this time, if the voltage generated by the high voltage generating circuit 4 is 30KV, no spark will be generated and no complete explosion will occur. At this time as well, when 1 second has elapsed after turning on the starter 2, a high voltage of 30 KV is applied to the spark plug 6 at 40° BTDC, where the pressure is low and the required voltage is low, so that discharge can be easily started. The resulting sparks cause a complete explosion.

In the above-mentioned embodiment, the ignition start signal switches from the _C2 signal to the _C1 signal when the starter energization time exceeds 1 sec, but this is possible if the time is set according to the engine. Alternatively, this time may be varied depending on the atmospheric temperature, cooling water temperature, etc. For example, when the atmospheric temperature is 20°C or higher and it is easy to start, this time may be set to 1 second, and when the atmospheric temperature is below -20°C and it is difficult to start, this time may be set to 3 seconds.

In addition, in the above-mentioned embodiment, the ignition start signal changes from _C2 when the starter energization time exceeds 1 sec.
C ₁ and this is starter 2
It is reset when power is turned off. However, this may be reset when the engine speed is detected and exceeds a certain set value. In this case, the cranking speed is normal
300 rpm or less, and the rotation speed at idle is normal
Since it is over 600 rpm, the set rotation speed is
Around 500rpm would be appropriate. In this case, it is better to reset the key switch even if it is OFF, in preparation for restarting the engine.

Furthermore, in the embodiment described above, the ignition start signal is C ₁
There are two points, a signal and a C ₂ signal, but this is set as the C ₂ signal only, and when the energization to the starter exceeds 1 second, the timer determines when to start applying high voltage to the ignition plug using the C ₂ signal. It may be arranged to advance by about 25 msec. (Since the cranking rotation speed when the starter is activated is approximately 200 rpm, the 30° crank angle at this time is approximately 25 msec.) As described above, the present invention can repeatedly or continuously ignite for one ignition. In the ignition method that applies high voltage to the ignition plug, the starter energization time when starting the internal combustion engine is detected, and when the time exceeds a set value, it is considered difficult to start, and in this case, high voltage is applied to the ignition plug. Since the timing at which the engine is applied is advanced compared to normal, if starting is difficult due to carbon deposits on the ignition plug, this carbon can be burned off to make starting easier. Even when the generated voltage does not reach the required voltage due to low battery voltage or extremely low temperatures, the required voltage can be reduced by advancing the engine, making it easier to start. It is easy to start when restarting or when the battery voltage is high enough,
If the internal combustion engine is started before the starter energization time exceeds the set value, the start timing of high voltage application to the ignition plug will not be advanced and will remain at the normal set value, preventing premature ignition. It has an excellent effect that it does not occur.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the overall configuration of an apparatus to which the method of the present invention is applied;
Figures a and 2b are a plan view and a front view of the date signal generator in the device shown in Figure 1, Figure 3 is an electrical circuit diagram of the ignition timing switching circuit in the device shown in Figure 1, and Figures 4 and 5 are 6 is a voltage waveform diagram of each part used to explain the operation of the above-mentioned display signal generating section and ignition timing switching circuit, and FIG. 6 is an electric circuit diagram of the high voltage generating circuit in the apparatus shown in FIG. 1. 1...Dice signal generator, 2...Starter, 3
...Ignition timing switching circuit, 4...High voltage generation circuit,
5...Dice high pressure distribution section, 6...Ignition plug.

Claims (1)

[Claims] 1. In an internal combustion engine ignition method that repeatedly or continuously applies a high voltage to a spark plug for one ignition, the starter energization time at the time of starting the internal combustion engine is detected, and the 1. A method for igniting an internal combustion engine, characterized in that when the ignition plug exceeds a set value, the timing at which high voltage application to the spark plug is started is advanced from the normal set value. 2. The ignition method according to claim 1, wherein the advance of the timing at which the high voltage application is started returns to the normal set value when the starter energization is cut off. . 3. The advance angle at which the high voltage application is started returns to the normal set value when the engine speed exceeds the set value and when the key switch is released. The ignition method described in Scope 1.