JPS58131346A - Electronic control apparatus for internal-combustion engine - Google Patents

Abstract

PURPOSE:To enable to introduce air without influence of ignition noises, by interrupting introduction of air when ignition noises are produced, in an apparatus for detecting the quantity of intake air by use of a hot-wire type air-flow meter. CONSTITUTION:Output signal of an air-flow meter 1 is applied to a control unit 3 via an A/D convertor. When an ignition transistor 5 is turned OFF, current supply to an ignition coil is interrupted and a high voltage is produced, so that a spark is produced. By starting a monostable multivibrator 4 in response to the OFF signal of the transistor 5, whether the time is within a predetermined period after ignition or not can be informed to the control unit 3. Thus, the control unit 3 can inform the time when ignition noises are produced to a computor by checking the output of the multivibrator 4, and the computor in turn stops A/D conversion in response to the signal from the control unit.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an engine control aI device, and more particularly to an electronic engine control device suitable for detecting an intake air amount using a hot wire air flow meter.

In recent years, quantization has progressed, with the use of microcomputers in engine control devices. Sensors and actuators that were not used in the past are now being used. Among them, the hot wire type air flow rate tt is small, @amount,
lIi! It is attracting attention for its I-speed response.

However, the output of this sensor is non-linear as shown in FIG. 1, and this output is processed and linearized by a so-called microcomputer within the control system. If noise is added to this pressure, it will become linear and the error will be magnified in the filtration phase, which will tend to have a large effect. On the other hand, in automobile systems, pressure is applied to the spark plug to emit sparks, so noise is unavoidable.

Experimentally, this noise level is approximately 15 mV on the hot wire signal line. In addition, during idling (air flow rate of about 20 kg/h) where there is a lot of noise, there is an error of approximately 3 points.

An object of the present invention is to provide a control device having a function of stopping intake of air flow when ignition noise occurs in order to eliminate the noise shadow 411r.

Hereinafter, the present invention will be explained according to examples.

FIG. 2 shows an embodiment of the present invention. 1 air flow 111
The output from the meter is input to the control device (3) through the A/L converter (2). On the other hand, ignition transistor 5 is off.
When F is selected, the current in the ignition coil is cut off, pressure is generated, and sparks fly. If the monostable multivibrator 4 is activated by the (JFF signal) of this transistor,
It is possible to inform the control device 3 whether it is within a predetermined time after ignition. i! II @ fj 11. Assuming a stored program microcomputer system and configuring the system with discrete input/output, checking the output of the multivibrator 4 will prevent the computer from generating noise. I can let you know if it's time. The computer receives this signal, stops performing the A/l)i conversion, and waits until No. 16 of the noise generation period ends.

FIG. 3 is an explanatory diagram of the operation of the monostable multivibrator shown in FIG. 2, and FIG. 3(A) shows the ignition signal applied to the power transistor 5. When this ignition signal is "1", the power transistor 5 is interrogated and the ignition coil 6 is connected to the primary coil *
'a flows, and the electromagnetic energy is corrected in the -order coil.

When the ignition signal becomes 1", the power transistor 5 is cut off and voltage is applied to the spark plug. - In response to the change of the ignition signal from 1" to 0", the monostable multivibrator is triggered, 1) A signal "'1" is applied to the IO terminal of the control device. When this signal is "1", it can be determined that the ignition operation is in progress. Figure 3 (H) is the ignition noise,
The pulse width of the monostable multivibrator is set to be longer than the duration of this noise.

FIG. 4 is a flowchart of the heat storage type air flowmeter 1,
It is performed for a fixed period of time longer than the time required for the A/D conversion to be fully completed. In step 2, it is determined whether the output QA of the flowmeter 1 taken in via the multiplexer has been digitally converted. If it is about the output QA of flowmeter 1, then check the flag IGNt in step 2,
If the value is 1"1", it is determined that ignition is in progress, and in step 6, the f-digital f value of the previous QA is substituted. On the other hand, if plug I(j
0)) Store in tAM. This result is used to determine fuel supply 1 and ignition timing. In step 12,
The next A/D f conversion is selected, the multiplexer is set, and the digital f converter is started to complete the program.

In step 12, an input other than &';1jQA is selected,
Therefore, QA is input every other time, and during the acquisition of Q), other inputs are digitally converted and the weight is increased. If there are a plurality of the above-mentioned other inputs at the same time, the other inputs are switched one by one in turn.

If 'NO' in step 2, only the digital 1- is taken in in step 14, and it is determined in step 16 whether ignition is in progress.If the input 4DlO in FIG. 2 is "l", ignition is not in progress; Flag ■ (0 at iNk step 18
'', and in step 20 select it with the QA multiplexer and start Al1)2. This causes the digital converter 2 to start the conversion operation. Stiffness 1]
[If it is, the ignition is in progress. In step 22, the flag IGN indicating that ignition is in progress is set to "1".

5 and 6 show other embodiments, FIG. 5 is a block diagram thereof, and FIG. 6 is a flowchart thereof. The same activation as in Figure 2 makes the same operating sound.

In response to a change in the ignition signal of FIG. 3A from 1" to '0" which activates the power transistor 5, the monostable multivibrator 9 is triggered. From the monostable multivibrator 9, an output similar to (1 and fK1 in FIG. 3) is passed to the base of the transistor 80 at a mark 71[], and is passed through the transistor 81r4 during ignition.

The flowchart shown in FIG. 6 is executed for a certain period of time, which is longer than the time required to completely complete the phase movement.

In step 2, the converted value 'fr is scattered and temporarily held. It is determined in step 4 whether the taken-in value is air amount QA data, and in step 6 it is determined whether ignition is in progress.

This judgment is disappointing because the amount of contact (1-QAQ) is less than that of the original. If the ignition is in progress, replace the clay imported in step 8 with the previously imported Q A 1111. In step 10, settings are made for the intake of human power other than air tQA. Make manual selection easier with a multiplexer. In step 12, it is set as regular human power, and in step 14, digital conversion 62t is started. On the other hand, if the intake value is low, then the air t
In order to import QA, execute or move from step 4 to step 16, and step the extracted digital 1st shift.

It will be officially stored on December 12th.

According to the VC of the present invention, the air is heated without receiving #w of ignition noise.
It is possible to import il.

[Brief explanation of the drawing]

Fig. 1 is a characteristic diagram of the thermal air mud tester, Fig. 2 is a block diagram of an example of unloading, Fig. 3a is an operation explanatory diagram of Fig. 2, and Fig. 4
The figure is a flowchart showing the second embodiment, FIG. 5 is a block diagram showing the second embodiment, and FIG. 6 is the second embodiment. It is a flowchart diagram showing lJ. 1...Thermal air at shochu, 2...Deinotal Shokoki,
3... system @l! 11.4.9...Simple isolator is multi-isolated. $6m.

Claims (1)

[Claims] 1. A signal for calculating the intake air 1lIi of the engine in response to the lI'L1 type air flow l1rPrtc/) signal, and increasing the fuel 1 corresponding to the appropriate air-fuel ratio to 5tfi'?
A single-child internal combustion engine control device that has a function of correcting the measurement of intake air amount for a predetermined period after outputting an ignition signal from an ignition device of the engine. 2. The electronic internal combustion engine side @ device according to item 1, which has a function of ignoring 1111 of the intake air amount measured during a predetermined period after outputting the ignition signal of the ignition device of the engine.