JPS5857071A - Ignition device of internal-combustion engine - Google Patents

Abstract

PURPOSE:To prevent a misfire from occurring during rapid acceleration or the like by providing a rapid discharge circuit discharging a condenser for a preset time after the first angle position is detected in an engine controlling the ignition timing in accordance with two angle position signals. CONSTITUTION:An internal combustion engine is provided with pickups 1, 2 detecting the first and second angle positions theta1, theta2, a one-shot multivibrator 4 generating an output signal in a preset time TM in response to the output from an FF 3 when the angle position theta1 is detected, and a charge circuit charging in proportion to the time after the TM time has elapsed and before the angle position theta2 is detected. This charge circuit is constituted with an NAND circuit 5, transistor Tr 6, and condenser 10. A discharge circuit is also provided discharging the condenser 10 through a Tr 9 for a constant time after the angle position theta2 is detected. Furthermore, a rapid discharge circuit made of a Tr 14 is provided rapidly discharging the condenser 10 after the angle position theta1 has been detected and before the TM time elapses.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an internal combustion engine ignition device with closed circuit rate control, and
The present invention relates to an internal combustion engine ignition system with an improved circuit closure rate control circuit.

, a conventional device of this type is disclosed in Japanese Patent Application Laid-Open No. 52-5623.
There is an internal combustion engine ignition system shown in No. 3, that is, in the internal combustion engine ignition system of this publication, the energization time of the primary current of the ignition coil varies depending on the rotational speed of the internal combustion engine, as shown in Figure 1. Regardless, it is a fixed time indicated by TD- and LKTM. However, the above-mentioned relational expression TD-KTM is a relational expression that holds true only when the number of rotations is constant and when the rate of change (increase or decrease) in the number of rotations is very small.

That is, when sudden acceleration such as full throttle is performed, the rotation angle of the engine increases rapidly, and the rotation period T of the engine becomes discontinuously shortened. If the rotation period T becomes short due to sudden acceleration, as shown by the broken line in FIG. 2, a Δ
The next charging starts with the charge that generates the voltage vC remaining, and the peak voltage 'v'p during charging becomes higher than the peak voltage Vp during steady state by about ΔVe. Therefore, if the acceleration state continues in the same way in the next cycle, the next peak voltage Vp"-Vp" = V p + 2 A V
c (Since the voltage increases at a rate of 0, the energization time to one ignition coil becomes shorter during sudden acceleration when the highest voltage is required for the engine, resulting in a shortage of secondary output voltage and ignition energy.) In addition, there was a drawback that misfires could occur in some cases.

Therefore, it is possible to prevent misfires by increasing the closed circuit ratio itself, but in this case, unnecessary current flows to the ignition coil even in steady state, resulting in energy wastage and the ignition coil generating heat. It will cause harm.

The present invention has been made in view of the above-mentioned problems, and it is an object of the present invention to provide an internal combustion engine ignition device that does not cause insufficient supply of primary current to the ignition coil or misfire even during sudden acceleration. shall be.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 3 shows an internal combustion engine ignition system according to the present invention. a NAND circuit in which a first input (negation) is connected to the output of the flip-flop 3, and a second input is connected to the output of the flip-flop 3;
6 is a PNP transistor whose pace is connected to the output of the NAND circuit 5 and 1 emitter is connected to the constant current power supply 7, 8 is a PNP transistor whose first negative input is connected to the monostable circuit g7Ir4, and the second negative input is connected to the 7rip 74 transistor. AND connected to the output of f3
The circuit, 9, is connected to the output of the AND circuit 8, the collector is connected to the collector of the above-mentioned PNP transistor, and the input terminal is grounded. capacitor, 11 is connected to W, the negative input of l is connected to one end of capacitor 10, and the other end is grounded;
ND circuit, 12 is a switching element connected to the output of the AND circuit 11, and 13 is an ignition coil connected to the switching element 12.

The ignition device of the present invention further reduces the charge of the capacitor 1o by
The internal combustion engine is provided with a rapid discharge time I6 that rapidly discharges during a period of time TM after the first angular position #stp of the internal combustion engine is reached. In this embodiment, as shown in FIG. 3, this rapid discharge circuit consists of an NPN transistor 14 whose pace is connected to the output of the monostable circuit 4, whose collector is connected to the capacitor 10/14, and whose emitter is grounded. There is.

Next, the operation of the ignition system of the present invention will be explained with reference to the waveform diagram of FIG. That is, when the first pickup l detects the first angular position 01 (see FIG. 1 a) of the rotary body and operates the flip-flop f70 knob 3, this flip-flop 077'
3) The monostable circuit 4 outputs the TM waiting time, which is a preset time, as shown in FIG. 1d. On the other hand, the second pickup 2 detects the second angular position θ of the rotating body (FIG. 1b), and this detection signal is input to the reset input of the 7 lip flop 3.
``The waveform shown in Figure 1 (!) can be obtained by using 70 Tsude 3.

The negative input of the NhND circuit 5 is connected to the monostable circuit 4, and the other input is connected to the output of the 7 rig 7 4 tsugu 3, so the clip 70 tube 3 is ONL, and the monostable circuit 4 is 0FFL. , that is, until the second angular position θ is detected after the TM time elapses, the transistor 6
is 0N-j, so the capacitor 1o is charged as shown in Figure 1. The time during which this capacitor 10 is charged is determined by the circuit closing rate iK, which is the ratio of the angular interval from the second angular position θ to the first angular position θ1 and one period T of the internal combustion engine.
In this case, it can be expressed as (1-K)T-TM. On the other hand, NAND circuit 8Fi where both inputs are negative human power,
When the 7 lipfrog 3 and the monostable circuit 4 are 0FFO, they are output and the transistor 9 is turned on, so that the charge of the charged capacitor 10 is discharged through the transistor 9. As shown in FIG. 1f, this discharge time is ((1-K) T
-TM) T-! This is until T time has elapsed.

In this way, after the charge of the capacitor 10 is discharged, the other NAND circuit 11 in which both inputs are negative inputs has 7 circuits 70 circuits 3 OFF, and the input from the capacitor 10 is '''
0'', so the TD time indicated by 2TM (Fig.
-K f) is output and connected to the ignition coil 13 via the switching element 12.
A primary current (see Fig. 1g) is supplied to the magnet to excite it. Therefore, the internal combustion engine can be ignited by this.

The above explanation is about the normal operation as in the conventional case, but next, the operation during sudden acceleration will be explained. That is, the ignition device of the present invention includes an NPN transistor 14't- whose pace is connected to the output of the monostable circuit 4, its collector is connected to one end of the capacitor 10, and its emitter is grounded. , while the monostable circuit 4 is operating,
That is, it is turned ON for the TM waiting time. Therefore, condenser during sudden acceleration? The charge that had generated the voltage Δve (see FIG. 4) across the capacitor 10 is completely discharged by the transistor 14 during the TM time, so that the voltage waveform across the capacitor 10 becomes as shown by the broken line in FIG. Therefore, regardless of the steady state or acceleration, the next cycle of charging can be performed with the capacitor 10 having no charge, that is, with the discharge completed, so that there is no possibility of insufficient current to the ignition coil 13 or misfire. It can effectively prevent stones.

As explained above, according to the present invention, a rapid discharge circuit is provided that discharges the charge of the capacitor for the TM waiting time after detecting the first angular position, so that the charge of the capacitor can be discharged even during sudden acceleration. Charging for the next cycle can always be carried out in a zero state, so that the ignition coil does not generate heat, the primary current can be supplied without any shortage, and misfires can be effectively prevented.

[Brief explanation of the drawing]

Figure 1 is a waveform diagram to explain the main operation of the ignition system, Figure 2 is a waveform diagram to explain the charge/discharge tube of a capacitor in a conventional ignition system, and Figure 3 is an ignition system according to the present invention. FIG. 4 is a waveform diagram for explaining charging and discharging of a capacitor in the ignition device of the present invention. 1.2... First and second pickup, 3... Slip frog, 4... Monostable circuit, 5, 8.11.
...NAND circuit, 6...PNP) transistor, 9
...NPN) transistor, 10... capacitor, 1
3...Ignition coil, 14...NPN) Lannostar. Agent Shin Kuzuno - Figure 1

Claims (1)

[Claims] First and second angular positions θ1 and θ! of the internal combustion engine. an angular position detection circuit that detects the first angular position θs', a fixed time generation circuit that operates for the TM waiting time and outputs the output after detecting the first angular position θs'; θ1
If the rotation period of the internal combustion engine is T, the angular interval from t to % occupies one cycle of the internal combustion engine. From a charging circuit that charges an electric charge proportional to the time (1-K)T-TM, a capacitor that is photoelectrically charged in the charging circuit, and the detection of the second angular position θ3, ((1-K) )T-TM), a discharge circuit that discharges the charge from the capacitor for a certain period of time at 1, and a time T- from the end of discharge of the capacitor to the detection of the angular position 01't- of the first position. TTMt-
In an internal combustion engine ignition system comprising an output circuit that excites the TD waiting time ignition coil in the case of TD, the above-mentioned TM
An internal combustion engine ignition device comprising a rapid discharge circuit for discharging the charge of the capacitor.