JPH0253632B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an engine ignition control device, and particularly to prevention of malfunction due to noise generated during ignition.

In recent years, with the development of electronic technology, engine ignition control devices are also rapidly becoming digital. In this case, in the engine ignition control device of a two-wheeled vehicle, it is attached to the crankshaft and attached to the outer periphery, for example.
A crank angle rotor with 2° pitch teeth and a reference position rotor that is attached to the crankshaft and has one protrusion on its outer periphery are provided.
The crank angle pick-up sensor detects the teeth of the crank angle rotor and extracts a crank angle signal every 2° rotation of the crankshaft, and the reference position pick-up sensor detects passage of the protrusion on the reference position rotor and generates a reference position signal. It has been taken out. When the ignition control section receives the reference position signal, it sequentially counts the crank angle signal as a clock signal to set the dwell angle and ignition timing, and controls the ignition coil via the driver. It is configured as follows.

However, the engine ignition control device configured in this way performs various controls digitally using pulse signals output from the reference position pick-up sensor and the crank-and-dal pick-up sensor, so its operation is extremely accurate. Although it is easy to perform complex control, it has a big problem of malfunctions caused by noise. That is, since the ignition control device applies a high voltage to the spark plug to forcibly generate a discharge, a high level of noise is generated when the discharge occurs and is induced into the signal line of the reference position pickup sensor. As a result, the ignition control device with a digital configuration mistakenly takes in this noise signal as the output of the reference position pickup sensor, resulting in the problem that ignition control based on the optimum ignition position cannot be performed. have.

For this reason, there are protection measures that generate a protection signal from immediately before the occurrence of the noise until the end of the noise and temporarily suspend the arithmetic processing of the digital computer of the control device (Japanese Patent Application Laid-Open No. 110302/1982), or a protection device that temporarily suspends the calculation processing of the digital computer of the control device. A method has been proposed in which the operation of the advance angle counting means is stopped for a certain period of time (Japanese Patent Application Laid-Open No. 131042/1983). However, these methods all have the disadvantage that the operation of the control device itself is stopped during that period, assuming that the control device itself is malfunctioning, and that the efficiency of use of the control system is reduced.

Therefore, an object of the present invention is to prevent ignition noise from being erroneously determined to be a reference position signal and outputting an ignition control signal at an inappropriate time without stopping the operation of the control device itself; When noise occurs at the same time as the control signal is generated, steady ignition is performed without stopping the generation of the ignition control signal along with the noise, and malfunctions due to ignition noise generated during ignition are prevented. An object of the present invention is to provide an engine ignition control device.

In order to achieve such an object, the engine ignition control device according to the present invention generates the ignition operation and ignition noise a little later than the ignition start control, and also picks up the reference position after a predetermined time delay from the generation of the ignition noise. Focusing on the fact that a detection signal is output from the sensor, the ignition noise is masked during a period that includes the ignition noise generation period but does not reach the reference position signal generation period, triggered by the ignition control signal output from the ignition control unit. The mask signal to be output from the monostable multivibrator circuit is outputted from the monostable multivibrator circuit, and the gate circuit inputs the mask signal and reference position signal output from the monostable multivibrator circuit, and controls the ignition control unit only during the output sending period of the monostable multivibrator circuit. By prohibiting input of ignition noise, ignition noise induced at a large level can be masked without masking the reference position signal.

Hereinafter, an engine ignition control device according to the present invention will be explained in detail using the drawings.

FIG. 1 is a circuit diagram showing an embodiment of an engine ignition control device according to the present invention. In the figure, 1 is a crank angle pick-up sensor installed on the outer periphery of the crank angle rotor attached to the crankshaft (not shown) of the engine, and detects the teeth of, for example, a 2° pitch; 2 and 3 are attached to the crankshaft. This is a reference position pick-up sensor that generates a reference position signal by detecting a protrusion provided on the outer periphery of a reference position rotor (not shown). They are located 180° apart from each other. 4 to 6 are waveform shaping circuits that shape the outputs of the crank angle pickup sensor 1 and the reference position pickup sensors 2 and 3, respectively. Reference numeral 7 denotes an ignition control section which controls the crank angle signal A supplied from the waveform shaping circuit 4 and the waveform shaping circuits 5 and 6 via AND gates 8 and 9.
This is an ignition control section that receives reference position signals B and C supplied from the ignition control section. The ignition control section 7 sets the dwell angle and the ignition timing by counting the crank angle signal A over a predetermined value using the reference position signals B and C as a reference, and then outputs the ignition control signal D. , E.

Reference numeral 10 denotes an OR gate which inputs the ignition control signals D and E outputted from the ignition control unit 7. Reference numeral 11 denotes an OR gate that receives the ignition control signals D and E outputted from the ignition control section 7, and 11, when triggered by the falling output of the OR gate 10, the output continues for a predetermined period of time. a mono-multivibrator circuit that inverts from "H" to "L"; 12 and 13 are drivers for driving ignition coils 14 and 15 controlled by ignition control signals D and E output from the ignition control section 7;
Ignition plugs 16 and 17 ignite the air-fuel mixture in the cylinder by receiving high voltage output from the ignition coils 14 and 15 and causing discharge.

In the engine ignition control device configured as described above, when the engine (not shown) is started, the crank angle pickup sensor 1 sequentially detects the teeth of the crank angle rotor that is attached to the crankshaft and rotates. By shaping the output in a waveform shaping circuit 4, a crank angle signal A is sent out as a rotation angle pulse of, for example, a pitch of 2 degrees. On the other hand, the reference position pick-up sensors 2 and 3 detect the protrusions of the reference position rotor mounted on the crankshaft at positions deviated from each other by 180 degrees, thereby generating a reference position signal B shown in FIGS. 2a and 2b. , C, which are shaped into pulses in waveform shaping circuits 5 and 6.

In this case, monostable multivibrator circuit 11
Since the mask signal outputted from the mask signal is "H" as shown in FIG. 7. When the ignition control unit 7 receives the reference position signals B and C, it counts the crank angle signal A using the reference position signals B and C as a reference.
The ignition control signals D and E that are sent from the time when the crank rotation amount K shown in Fig. 2 c and d are detected are set to "H".
Set to . Then, this ignition control section 7
As shown in Figures c and d, at the time when the rotation of the predetermined dwell angle Q is detected, the ignition control signals D and E are changed from "H" to "L" as shown in Figure 2c.
Switch to . However, these ignition control signals D, E
It is necessary to match the point at which the switch from "H" to "L" approximately to the optimum ignition position of the crankshaft, and therefore, the dwell angle Q and the rotation angle K are set by back calculation based on the optimum ignition position.

In this way, when the ignition control signals D and E sent from the ignition control section 7 change as shown in FIG. Supply current.
Then, the ignition control signals D and E change from “H” to “L”.
At the point when the ignition coils 14 and 15 are reversed to
When the supply current to ignition coil 1 is cut off, the ignition coil 1
As is well known, high voltages are generated at spark plugs 4 and 15, and these high voltages are supplied to spark plugs 16 and 17, respectively, and are discharged to cause ignition. In this case, the spark plug 16,
The discharge at 17 is generated at a delay of several + microseconds. Therefore, each reference position pick-up sensor line has a signal from the ignition start point of the ignition control signal (the falling point of the ignition control signals D and E shown in FIG. 2 c and d) as shown in FIG. 2 a and b. is also induced as noise N at a slightly delayed position. The reference position signals B and C are outputted from the reference position pickup sensors 2 and 3 with some delay after the occurrence of the noise N.

On the other hand, since the OR gate 10 supplies the ignition control signals D and E outputted from the ignition control section 7 to the monostable multivibrator circuit 11, the monostable multivibrator circuit 11 receives the ignition control signals D and E from the ignition control section 7. It is triggered every time the signal goes low, and the output mask signal becomes "L" only for a predetermined period of time T, as shown in FIG. 2e. In this case, the operating time of the monostable multivibrator circuit 11, that is, the time T when the output becomes "L", is the ignition control signal D,
Noise N from the start of ignition (falling point) of E
The period is set in a range in which the generation of the reference position signals B and C is completely completed and does not include the generation period of the reference position signals B and C. In this way, when the output mask signal of the monostable multivibrator 11 becomes "L" for only time T, the AND gates 8 and 9 are closed and the supply of the noise N to the ignition control section 7 is prohibited. Therefore, “L” of the monostable multivibrator circuit 11
The output will act as a masking signal for the noise N generated during ignition. As a result, the ignition control section 7 receives only the reference position signal from which the ignition noise N has been removed, thereby ensuring stable ignition control operation without being affected by noise.

In the above embodiment, the case was explained in which the trigger was applied at the falling edge of the ignition control signals D and E in order to shorten the operation time of the monostable multivibrator circuit 11 and improve the operation accuracy. It goes without saying that the trigger may be triggered at the rising edge of the ignition control signal if a suitable operating time can be secured.

As explained above, the present invention is triggered by an ignition control signal output from an ignition control unit as a signal for driving an ignition coil, and starts ignition during a period that includes an ignition noise generation period and does not reach a reference position signal generation period. A monostable multivibrator circuit generates and outputs a mask signal to mask noise, and the mask signal and reference position signal output from the monostable multivibrator circuit are input, and ignition is performed only during the period when the monostable multivibrator circuit outputs output. By installing a gate circuit that prohibits the input of ignition noise to the control unit, the ignition noise induced at a large level is masked without masking the reference position signal, and the ignition noise is also misidentified as the reference position signal. This prevents malfunctions such as outputting ignition control signals at inappropriate times, and also prevents the generation of ignition control signals from being stopped along with the noise when noise occurs at the same time as the generation of ignition control signals. This has the effect of causing proper ignition. In addition, since the ignition control unit does not need to be stopped during the ignition noise generation period, the internal CPU can directly perform controls other than ignition timing, such as fuel injection and EGR control, which improves the utilization efficiency of the control device. It has excellent effects such as no deterioration.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing an embodiment of an engine ignition control system according to the present invention, and FIGS. 2 a to 2 e are operational waveform diagrams of each part of the circuit shown in FIG. 1. 1...Crank angle pick-up sensor,
2, 3...Reference position pick-up sensor, 4-6...
Waveform shaping circuit, 7... Ignition control section, 8, 9... AND gate, 10... OR gate, 11... Monostable multivibrator circuit, 12, 13... Driver, 1
4, 15... Ignition coil, 16, 17... Spark plug.

Claims (1)

[Scope of Claims] 1. Ignition control that generates an ignition control signal by inputting and calculating a crank angle signal generated every predetermined unit angle rotation of the crankshaft and a reference position signal representing the reference position of the crankshaft. and an ignition coil that is driven by an ignition control signal output from the ignition control unit to generate a high voltage and supply the high voltage to the spark plug, the engine ignition control device comprising: a monostable multivibrator circuit that is triggered by an ignition control signal that is generated and outputs a mask signal that masks ignition noise during a period that includes an ignition noise generation period and does not reach a reference position signal generation period; Input the mask signal output from the stable multivibrator circuit and the reference position signal,
An engine ignition control device comprising: a gate circuit that prohibits input of ignition noise to the ignition control unit only during an output transmission period of the monostable multivibrator circuit.