JPS58170853A - Engine ignition timing control device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ignition timing control device for an engine, and in particular controls ignition timing based on an engine intake air amount signal, an engine rotation speed signal, a throttle position signal, etc. The present invention relates to an ignition timing control device for an engine that performs feedback control of the air-fuel ratio of an air-fuel mixture according to an air-fuel ratio signal detected by an exhaust system of an engine.

In recent years, in order to both reduce exhaust emissions and improve fuel economy of automobile engines, efforts have been made to dilute the air-fuel mixture and recirculate large amounts of exhaust gas.
These factors are responsible for increasing engine cycle-to-cycle combustion fluctuations. Even in air-fuel ratio feedback control and back pressure feedback control for exhaust gas recirculation, periodic fluctuations in the air-fuel ratio and exhaust gas recirculation rate tend to impair vehicle drivability. Therefore, although reducing combustion fluctuations is extremely important, it cannot be said that sufficient effective measures have been taken in the past.

In other words, in a conventional engine equipped with an electronic control circuit that performs feedback control of the air-fuel ratio of the air-fuel mixture supplied to the engine combustion chamber in accordance with an air-fuel ratio signal detected in the exhaust system, the air-fuel ratio of the air-fuel mixture supplied to the engine is The fuel ratio is controlled to be close to the stoichiometric air-fuel ratio, but since feedback control is being performed, air-fuel ratio fluctuations will always occur, albeit slightly, every control cycle.
This was one of the causes of combustion fluctuations.

SUMMARY OF THE INVENTION An object of the present invention is to provide an engine ignition timing control device that eliminates the drawbacks of the prior art described above, reduces combustion fluctuations, and improves vehicle drivability.

In order to achieve the above object, the present invention provides a mixture that is supplied to an engine combustion chamber when air-fuel ratio feedback is performed when it is detected by a throttle position signal that the throttle opening is in an idling position. Only when the air-fuel ratio of the engine is corrected to the lean side, the ignition timing tube is controlled to the advanced side in accordance with the correction amount.

Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIG. 1 is a block diagram showing an embodiment of an engine ignition timing control device according to the present invention. The embodiment shown in this figure includes an air cleaner 2 and an air flow meter 4 as an intake air 1 sensor provided downstream of the air cleaner 2. The air flow meter 4 is rotatably installed in the chamber 4A and is connected to a convention plate 4B.
and a potentiometer 4C that detects the opening degree of the compensation play (4B). Therefore, the intake air amount is detected as a voltage (intake air amount signal) 100 output from the potentiometer 4C. Further, an intake air temperature sensor 6 is provided near the air flow meter 4 to detect the temperature of the intake air and output an intake air temperature signal 102.

A throttle valve 8 is disposed downstream of the air 70-meter 4, and a throttle sensor 10 such as a throttle switch that detects the opening of the throttle valve and outputs a throttle position number 104 is located near the throttle valve 8. It is located. A surge tank 1 is located downstream of this throttle valve 8.
2, and this surge tank 12 is provided with a detour 14 that bypasses the throttle valve 8. and,
This bypass path 14 is provided with an intake air flow rate control valve 18 that is controlled by a step motor 16 .

The intake air flow rate control valve 1B has its valve opening degree controlled by the intake air flow rate control device drive signal 106 when the engine is idle, and allows intake air to flow into the surge tank 12 bypassing the throttle valve 8. This controls the engine speed to a target value.

The surge tank 12 includes an intake manifold 2.
0 is connected, and this intake manifold 20
A fuel injection device 22 is arranged to protrude inward. The fuel injection device 22 is configured such that its fuel injection time is controlled by a fuel injection signal 108, and the air-fuel ratio of the mixture mixed with intake air and supplied to the combustion chamber of the engine 24 can be controlled. The intake manifold 20 is connected to a combustion chamber of an engine 24, and the combustion chamber of the engine is connected via an exhaust manifold 26 to a catalytic converter 28 filled with a three-way catalyst.

The exhaust manifold 26 also detects the residual oxygen concentration in the exhaust gas of the engine and outputs an air-fuel ratio signal 1.
An oxygen concentration (0,) sensor 30 that outputs 10 is provided, and therefore, the engine 24 supplies oxygen to the combustion chamber of the engine 24 in response to an air-fuel ratio signal 110 from the 02 sensor 30, which will be described in detail later. The air-fuel ratio of the air-fuel mixture is feedback-controlled.

The engine 24 is equipped with a water temperature sensor 32 that detects the engine cooling water temperature and outputs a cooling water temperature number 112.
are provided as shown.

The spark plug 34 of the engine 24 is connected to a distributor 36 to be supplied with ignition voltage 114, and the distributor 36 is connected to an igniter 38.
It is connected to the. The igniter 38 receives the ignition signal 11
6 supplies the ignition voltage 118 to the distributor 36 and outputs the ignition confirmation signal 120. Note that 40 is a transmission, 42 is a vehicle speed sensor capable of outputting a vehicle speed signal 122, and 44 is an ignition switch capable of supplying an ignition switch signal 124. The transmission 40 is provided with a shift position sensor 46 which detects the neutral position and drive position of the shift lever and includes a shift lever neutral start switch and the like.

Further, the distributor 36 is provided with a gear-shaped signal rotor fixed to the distributor shaft and a pickup attached to the distributor housing opposite to the teeth of the signal rotor, so that the signal rotor rotates. An engine rotational speed signal 128 is output by changing the amount of magnetic flux passing through the reinforcement. This timing rotor and pick amplifier constitute an engine rotation speed sensor.

The electronic control circuit 48, to which signals from the various sensors described above are input, stores in advance the ignition timing table shown in FIG. An appropriate ignition timing suitable for the engine condition is selected from the ignition timing table, the selected value is corrected according to the throttle position signal 104 to control the ignition timing accurately, and the air-fuel ratio supplied to the engine combustion chamber is controlled. , the air-fuel ratio signal 1 from the sensor 30
10, the fuel injection time of the fuel injection device 22 is controlled and feedback controlled.

More specifically, the electronic control circuit 48 includes a random access memory (RAM) 50 as shown in FIG.
, read-only memory (ROM) 52, central processing unit (CPU) 54, input/output circuit (Ilo) 56, and analog-to-digital conversion! a (ADC) 58 and backup random access memory (BU-RAM) 60
It is composed of: Note that the BU-RAM 60 receives power from a separate battery BT, and the stored contents are not erased except by a write command.

These RAM50, ROM52, CPU54, l10
56, ADC58 and BU-RAM60. are connected to a data bus 62. RO of electronic control circuit 48
The M52 stores an ignition timing table shown in FIG. 3, programs for implementing ignition timing control, air-fuel ratio control, idle speed control, etc. for operating the engine 24, and other programs.

Figure 3 shows an ignition timing table, with the vertical axis representing engine speed NE and the horizontal axis representing intake air amount Q and engine speed Ns.
The ratio with c is taken respectively.

l1056 includes a vehicle speed signal 122 output from the vehicle speed sensor 42, an engine rotation speed signal 128 output from the distributor 36, a throttle position signal 104 output from the throttle sensor 10, and a shift position sensor 4.
The shift position signal 126 output from the ignition switch 44, the ignition confirmation signal 120 output from the igniter 38, the air-fuel ratio signal 110 output from the sensor 30, etc. are input. At the same time, an intake air amount control device drive signal 106 that controls the intake air amount control device 18, a fuel injection signal 108 that controls the fuel injection device 22, an ignition signal 116 that controls the igniter 38, etc. are output. The ADC 58 also receives an intake air amount signal 100. which is output from the air 70 meter 4. An intake temperature signal 102 output from the intake temperature sensor 6 and a water temperature signal 112 output from the water temperature sensor 32 are input, and each signal is
The DC 58 converts the signal into a digital signal. Note that the maps and tables stored in the ROM 52 and the signals input and output to the l1056 and ADC 58 are such that various maps and tables are stored and various signals are input or output depending on the control state of the engine. It has become.

The operation of the nine embodiments constructed as above will be explained with reference to FIGS. 4 to 6.

FIG. 4 is an explanatory diagram showing a general mechanism for determining ignition timing. FIG. 5 is a flowchart shown to explain the operation of the advance angle control device according to the present invention. FIG. 6 is a timing chart showing the relationship between the advance angle and the air-fuel ratio correction coefficient, in which time is plotted on each horizontal axis, and
The vertical axis (A) represents the air-fuel ratio correction coefficient, and the vertical axis (B) represents the advance angle amount.

First, the general mechanism for determining ignition timing will be briefly explained.

Engine speed signal 12 from distributor 36
8 consists of a signal %E for detecting the crank angle reference position and a signal G for cylinder discrimination and top dead center detection, and the crank angle reference position detection signal is used to detect the engine rotation speed Ng. Together with the signal G, it is used to determine the timing to start energization and the timing to cut off the current.

That is, the crank angle reference signal LfE from the distributor 36 is taken into the advance angle determination processing section 70 and the energization time determination section 72. Further, the intake air amount signal 100 from the air 70-meter 4 is similarly transmitted to the advance angle determining section 7.
It is set to 0.

The advance angle determining unit 70 first calculates the engine speed NE obtained from the crank angle reference signal BE and the intake air amount signal (Q).
100, a predetermined ignition timing value is selected and taken out from the ignition timing table shown in FIG. Next, the ignition timing value is corrected based on the cooling water temperature signal 112 from the cooling water temperature sensor 32 and the throttle position signal 104 from the throttle position sensor 10, and is supplied to the energization time start timing and cutoff timing determining section 74. do.

On the other hand, the energization time determination unit 72 calculates the energization time based on the acceleration signal of the throttle position signal 104 from the throttle position sensor 10, the engine rotation speed signal Nz, and the battery voltage from a battery (not shown). That is, the energization time determination unit 72 calculates the energization time from the battery voltage and engine rotational speed signals, and also corrects the energization time so that it becomes longer when detecting the acceleration signal. In this way, to control the energization time,
This is to optimize the energization time, secure the necessary energization time, and preserve the igniter (its power transistor).

Then, it takes in the signals from the advance angle determining section 70 and the energization time determining section 72, and also takes in the engine rotation speed Ng and the signal G.
The ignition signal 116 is formed by the start timing and cutoff timing determining section 74 and supplied to the igniter 38, and the igniter 38 supplies the generated ignition voltage 118 to the spark plug 34 via the distributor 36.

Next, air-fuel ratio feedback control will be briefly explained.

The air-fuel ratio signal 110 from the exhaust manifold 26 of the engine 24, that is, the sensor 30 provided in the exhaust gas, etc., is taken in from the l1056 of the electronic control unit 48, and is proportionally integrated as shown in FIG. 6(A) to determine the air-fuel ratio. A correction coefficient signal is formed. The fuel injection signal formed based on the air-fuel ratio correction coefficient signal from l1056 controls the fuel injection device 22 as the fuel injection signal 108. That is, the fuel (i.e., the air-fuel ratio of the air-fuel mixture supplied to the engine combustion chamber) is feedback-controlled based on the oxygen concentration of the exhaust gas (i.e., the air-fuel ratio signal 110 from the sensor 30). Therefore, periodic fluctuations occur in combustion during feedback control.

Therefore, if air-fuel ratio feedback control had been performed when the throttle position signal 104 from the throttle position sensor 1o was at the idle state position, it would have been possible to
) As shown in Figure 6 (B), only when the air-fuel ratio correction coefficient is on the 1-in side, the advance amount is changed to the advance side as shown in Figure 6 (B) depending on the air-fuel ratio correction coefficient on the 1-in side. The above-mentioned periodic filling is prevented by correcting.

Further, to explain in detail with reference to FIG. 5, during the ignition timing control, in step s1, the throttle position sensor 1
It is determined whether the throttle position signal 104 from 0 is an idle position. Such an idle state occurs during idle link and deceleration states. In this step s1, when the throttle position signal 104 is in the idle position, the process moves to step S2, and on the other hand, when it is not in this state, nothing is done and the process moves to other processing.

Further, in step S2, the electronic control circuit 48 determines whether air-fuel ratio feedback control is being executed. In this step S2, if the air-fuel ratio is being fed back, the process moves to step S3, whereas if the air-fuel ratio is not being fed back, nothing is done and the process moves to other processes as described above. Further, in step S3, the air-fuel ratio correction coefficient (see FIG. 6(A)) during air-fuel ratio feedback is set to 1.
Only when the ignition timing is on the lean side, the advance angle determining section 70 corrects the ignition timing to the advance side in accordance with the value (or amount) to be corrected to the lean side. The amount by which the ignition timing is corrected to the advance side is made proportional to the area value of the integral value of the air-fuel ratio correction coefficient shown in Fig. 6 (A) on the lean side, that is, the value on the lean side. . Then, the ignition timing signal obtained and corrected in this way is passed through the energization start timing and cutoff timing determining section 74 as an ignition timing signal, and the ignition timing signal 11 is outputted from l1056.
6 and is supplied to the igniter 38.

In this way, this embodiment works to prevent periodic fluctuations in combustion.

The present invention is as described above, but in short, when the throttle position signal is in the idle position and air-fuel ratio feedback is being performed, the air-fuel ratio of the air-fuel mixture supplied to the engine combustion chamber is adjusted to exhaust. When the air-fuel ratio is corrected to the lean side using the air-fuel ratio signal detected in the above, the ignition timing is corrected to the advance side according to the amount by which the air-fuel ratio is corrected to the lean side. All such advance angle corrections fall within the scope of the present invention.

As described above, according to the present invention, since combustion fluctuations can be prevented, the drivability of the vehicle is improved.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of an engine ignition timing control device according to the present invention, FIG. 2 is a block diagram showing the configuration of an electronic control circuit used in the present invention, and FIG. The fourth factor is a block diagram showing a mechanism for determining the advance angle in the present invention. FIG. 5 is a flow chart shown to explain the operation of an embodiment of the present invention. FIG. is a timing chart shown for explaining the operation of one embodiment of the present invention. 4... Air flow meter, 4C... Intake air amount sensor, 8... Throttle valve, 10... Throttle position sensor, 22... Fuel injection device, 24... Engine, 30... Oxygen concentration sensor, 32...Cooling water temperature sensor, 34...Spark plug, 36...Distributor, 38...Igniter, 48...Electronic control circuit, 50...Random access memory (RAM)
, 52... Ri-only memory (ROM), 54...
・Central processing unit (CPU), 56 ・Input/output circuit (
Ilo), 58...Analog-digital converter (AD
C) , %0...advance angle determining section, 72... energizing time determining section, 74... energizing start timing and cutoff timing determining section,
100... Intake air amount signal, 104... Throttle position signal, 108... Fuel injection signal, 110... Air-fuel ratio signal, 116... Ignition signal. Agent: Tatsuyuki Unuma (and 2 others)

Claims (1)

[Claims] (1) An intake air amount sensor that detects the intake air amount of the engine and outputs an intake air amount signal, an engine speed sensor that detects the engine speed and outputs an engine speed signal, and a throttle valve opening sensor that detects the engine speed and outputs an engine speed signal. a throttle sensor that detects the temperature and outputs a throttle position signal; an oxygen concentration sensor that detects the residual oxygen concentration in the engine exhaust gas and outputs an air-fuel ratio signal; and an oxygen concentration sensor that receives each signal from the valley sensor. , an electronic control circuit that controls ignition timing based on an intake air amount signal, an engine rotational speed signal, and a throttle position signal, and feedback-controls an air-fuel ratio of an air-fuel mixture supplied to an engine combustion chamber in accordance with the air-fuel ratio signal; When the electronic control circuit detects that the throttle is in the idle position based on the front d-piston throttle position signal, and when air-fuel ratio feedback is being performed, the electronic control circuit detects that the air-fuel ratio is in a lean state. A JZ control device for engine ignition, characterized in that the ignition timing is controlled to advance in accordance with the amount of correction only when correction control is performed.