JPS63285268A - Ignition timing control device - Google Patents

Abstract

PURPOSE:To make normal car running possible even when a cylinder identifying signal (SGC) has ceased by providing a distributing means to distribute driving signal to each ignition coil on a cylinder identifying signal with a maintaining means to maintain the distribution order of the driving signal when the cylinder identifying signal has ceased. CONSTITUTION:Outputs of SGT, SGC generated by a crank angle sensor 7 and of AFS5 are inputted into an ignition control part 10, from which a driving signal is sent to ignition coils 8, 9 to spark an ignition plug 2. In this case, when SGC level is reversed from L to H, a distributing counter is reset to a zero position, and when the SGC level is not reversed as above-mentioned, the distributing counter is reset to the position of +1. In the case of the distributing counter reset at the zero position, the SGC on a H level is output to a port P6, and that on a L level is output to a port 7, and in the case of the distributing counter reset at the position of +1, the SGC on the L level is output to the port P6, and that on the H level is output to the port P7. Thus, when SGC has ceased, the outputs of the ports P6, P7 are the same as those at normal state to make the normal ignition of an engine possible.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an ignition timing control device for a low voltage power distribution system of an engine.

[Conventional technology]

Ignition timing control devices for engines include a high-voltage power distribution system that distributes high-voltage power to each cylinder via a rotor, and a low-voltage power distribution system that provides an ignition coil for each cylinder and distributes low-voltage power to each ignition coil.

This low-voltage power distribution system has the advantages of improving engine performance by increasing ignition energy, reducing noise sources by eliminating high-voltage power distribution, and improving the product image.

Figure 1 shows an ignition timing control device for a low voltage power distribution system.
1 is a four-cylinder engine, 2 is a spark plug provided for each cylinder, 3 is a throttle valve provided in the intake pipe 4,
5 is a Karman vortex air flow sensor (abbreviated as AFS), which is installed at the entrance of the intake pipe 4 and detects the amount of intake air;
is an air cleaner installed on the inlet side of AFS5,
No. 7 is a crank angle sensor that detects the rotation of engine 1, and outputs a crank angle reference signal (SGT) and a cylinder identification signal (SG
C) is generated. 8 is an ignition coil that applies high voltage to the ignition plugs 2 #l and #4, 9 is an ignition coil that applies high voltage to the ignition plugs 2 #2 and #3, 10 is an ignition control unit, 1) to 13 is the ink face, 14.15 is the first.
Second counter, 16 to 18 are first to third timers, 1
9 is a CPU having ROM and RAM, 20.21 is an AND circuit, 22.23 c)' driver, and 24 is an A/D converter.

In the above configuration, the outputs of SOT, SGC, and AFS5 are input to the ignition control unit 1o, and drive signals are alternately sent from the ignition control unit 1o to the ignition coil 8.9 via the driver 22.23. #4 spark plug 2 and #2.
The #3 spark plug 2 is alternately ignited, and the #1 to #4 cylinders are ignited in sequence (when one cylinder is in the compression stroke, the other cylinder is in the exhaust stroke, so both cylinders are ignited at the same time). There is no such thing).

[Problem that the invention seeks to solve]

However, in the conventional device described above, the distribution of the drive signal to each ignition coil 8.9 depends on the SGC, and therefore, due to poor contact of the connector, disconnection of the vehicle harness, defective crank angle sensor 7, etc. When an abnormality occurs, the drive signal cannot be distributed normally, resulting in an inability to run or damage to the engine 1 due to erroneous ignition.

Figure 2 (A) shows the operating waveforms of each part during normal SGC, (al is s a c :, tb+ is SGT,
(C) is the output of the third timer I8, (dl is the CPU
This output is H if SGC is H at the rising edge of SGT, and L if SGC is H at the rising edge of SGT.

(e) shows the output of boat P7, and when P6 is H, it is L
When it is SL, it is H. The AND circuit 21 has a timer 18
Since the output of P6 and P6 are input, the #1/#4 drive signal via the driver 23 becomes as shown in figure ff1, and the #2/#3 drive signal output from the driver 22 similarly becomes (gl As shown in the figure, the output of the timer 18 is alternately outputted, and during this time the ignition coil 8.9 is energized, causing the ignition plug 2 to generate a spark when cut off, and igniting each cylinder in sequence.

FIG. 2(B) shows the operation waveforms of each part when the SGC is interrupted, and the SGC is missing the dotted line portion (as shown in al), and the SGT shown in (bl) is the same as in normal times.

The output for the first day of the timer is also normal (like C1). The outputs of P6 and P7 are as shown in (d) and (e), and each drive signal is as shown in (ft, (gl). Therefore, ,(
Among the phantom drive signals, those indicated by diagonal lines were misdistributed, resulting in either the vehicle being unable to run or the engine being destroyed due to erroneous ignition.

゛ This invention was made to solve the above-mentioned problems, and even when the cylinder identification signal (SGC) is interrupted, the drive signal can be normally distributed to the ignition coil, The object of the present invention is to obtain an ignition timing control device that enables smooth driving.

Means for Solving Problem C] The ignition timing control device according to the present invention maintains the distribution order when the cylinder identification signal is interrupted in the distribution means that distributes the drive signal to each ignition coil based on the cylinder identification signal. The distribution order maintaining means is provided to maintain the distribution order.

[For production]

The distribution means in this invention maintains the distribution order of drive signals to the ignition coils even when the cylinder identification signal is interrupted.

Therefore, the engine continues to rotate normally.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings. The configuration is the same as in FIG.

FIG. 5(A) shows a main routine showing the operation of the ignition control section 10, in which initialization is performed in step 101, and step 1
In 02, the panteri voltage v1 is converted to A by the A/D converter 24.
/D conversion and input to the CPU 19. In step 103, the intake air amount AN in one intake period is determined by the crank angle reference signal (S
GT) period T SGT and AFS5 output period TAF8
Calculate from. In step 104, the engine rotational speed N1 is calculated from T. In step 105, CP
Ignition timing data θ is calculated from the map shown in FIG. 6(A) stored in the ROM of U19, and in step 106, energization time data Tl1HtL is calculated from the map shown in FIG. 6(B) also stored in the ROM. Calculate, step 10
Return to 2.

FIG. 5(B) shows the interrupt processing of the output of the AFS5, and in step 201, the AFS counted by the first counter 14 is
Read the output pulse period TAFS of FS5, step 2
At 02, the counter 14 is reset.

FIG. 5(C) shows the interrupt processing at the rising edge of SGT. In step 301, the SGT period Tsr+t is counted and read by the second counter 15, and in step 302, the counter 15 is reset, and step TA TawtL is calculated. do. In FIG. 4, (al is the SGT waveform, (
b) shows the waveform of the second timer 17, (cl shows the waveform of the third timer 18, the timer 18 rises at the fall of the timer 17, and energization is started. TA is the waveform from the rise of SGT to the end of energization. , and To is the time from the rise of SGT to the start of energization.In step 304, timer 1
To is set to 7, and in step 305, TD and 1tL are set to the timer 18. In step 306, the timer 17 is triggered. In step 307, the SGC level is read, and in step 308, the SGC level changes from L to ■.
(It is determined whether or not it has been reversed. If it is reversed, the distribution counter is reset to 0 in step 309. If it is not reversed, the distribution counter is incremented by 1 in step 310. In step 31), the distribution counter is reset to 0 in step 309. is 2 or not, and if it is 2, the distribution counter is set to 0 in step 312.
and if it is not 2, that is, 1, step 31
Proceed to step 3. In step 313, the distribution counter is 0 or 1.
If it is O, in step 314, P6 is set to ■(
is 0UTL, and in the case of ■, P6 is L in step 315.
OUT. In step 316, the distribution counter is set to 1.
If it is 1, output H to P7 in step 317, and if it is O, output L to P7 in step 31B.
OUT.

The operating waveforms of each part when the SGC is normal are shown in Figure 2 (A).
is the same as FIG. 3 shows waveforms of various parts when SGC is interrupted. In this case, even if SGC is interrupted as shown in (al), (dl, (as shown in el), P6°, P
7 remains unchanged from normal, the ignition coil drive signal is distributed normally, and normal ignition is performed. FIG. 5 (In the flowchart of C1, if normal, step 30
The output of 8 repeats YES and NO, and the distribution counter becomes 0. If there is an abnormality, the output of step 308 will continue to be NO twice or more, but even in this case, the distribution counter will repeat 0.1, no different from the normal state.

In the above embodiment, one timer 18 constituting the drive signal generating means is provided, and its output is distributed. However, the same number of timers as the number of ignition coils are provided, and a trigger signal for starting each timer is provided. It may be distributed. In this case, a drive signal with a circuit closure rate of 100% or more can be achieved.

〔Effect of the invention〕

As described above, according to the present invention, even if the cylinder identification signal is interrupted due to poor contact of the connector while the engine is running, the function of distributing the drive signal to the ignition coil is performed normally, so the running function is not affected. Therefore, there is no damage caused by erroneous ignition of the engine, and the reliability of the ignition function can be improved.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of a conventional ignition timing control device and the present invention, Fig. 2 (A) and (B) are operation waveform diagrams of the cylinder identification signal of the conventional device in normal and abnormal conditions, respectively, and Fig. 3 is a An operational waveform diagram of this invention device when the cylinder identification signal is abnormal, FIG. 4 is a partially enlarged operation waveform diagram of this invention device, and FIGS.
) is a flowchart showing the operation of the device of this invention, and FIGS. 6(A) and 6(B) are characteristic maps stored in the ignition timing control section of this invention. 1... Engine, 2... Spark plug, 5... Air flow sensor, 7... Crank angle sensor, 8.9...
・Ignition coil, 10...Ignition control section, 16-18...
・Timer, 19...CPU, 20.21...AND circuit.

Claims (1)

[Claims] (1) From the outputs of the load detection means for detecting the load on the engine, the rotation speed detection means for detecting the engine rotation speed, the cylinder identification signal generation means for generating the cylinder identification signal, the load detection means, and the rotation speed detection means, calculation means for calculating the optimum ignition timing; drive signal generation means for generating a drive signal corresponding to the ignition timing for each ignition coil provided for each cylinder; and drive signal generation means for each ignition coil based on the cylinder identification signal. An ignition timing control device comprising a distributing means for distributing fuel to the cylinders in an orderly manner, wherein the distributing means has a distributing order maintaining means for maintaining the distributing order even when a cylinder identification signal is interrupted.