JP3140200B2 - Control device for internal combustion engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for controlling an ignition timing of an internal combustion engine, and more particularly, to a method of controlling an ignition advance value determined in accordance with an operating state of an engine with a time width from a reference point of each cylinder. The present invention relates to a so-called time control type ignition timing control method and device, in which measurement is performed and the measurement end point is set as an ignition position. The invention also relates to a sensor for generating a signal indicative of the above-mentioned reference point used in the device.

[0002] The present invention can also be applied to a fuel injection control device.

[0003]

2. Description of the Related Art JP-A-2-83452 and JP-A-2-14046
In the time control type internal combustion engine ignition timing control device disclosed in Japanese Patent Publication No.
The rising edge of the generated pulse signal is used as the measurement start position (timing) of the time width (ADVT) corresponding to the ignition advance value, and the position is also referred to as TD. The time width corresponding to the advance value is calculated based on the engine speed at.

[0004]

For this reason, if the rotation speed fluctuates after the measurement is started with the rising edge of this pulse as the measurement start point, the ignition timing will be deviated or the energization time to the ignition coil will be longer than necessary. There is a problem that it becomes longer or shorter.

[0005] In particular, when the ignition advance value is small or a retard value is taken such as when combined with a knocking control device, the time width from the measurement start point becomes long, so that errors tend to occur.

This error has an error characteristic as shown in a solid line in FIG. 15 or as shown in FIG.

In the fuel injection control, there is a similar problem because the output pulse of the same sensor is used.

An object of the present invention is to reduce an error based on the rotation fluctuation in the method and the apparatus for controlling the fuel injection ignition timing of the time control type internal combustion engine. It is another object of the present invention to provide a sensor used to achieve this object.

[0009]

In order to achieve the above object, according to the present invention, an ignition timing is advanced according to an operating state of an engine.
Map with stored values, multiple cylinders provided before top dead center of each cylinder
Determine the ignition timing measurement start point from among the reference points, and
The time width corresponding to the advance value read from the
From the ignition timing of the preceding cylinder
Energization that determines the starting point of energization of the ignition coil of the following cylinder
Control means, a characteristic of the plurality of reference points which is close to the top dead center;
The energization start point is set closer to the top dead center than a fixed reference point
Characterized by having an energization start point control means for preventing
Internal combustion engine control device .

The sensor uses a disk provided with a slit for generating a signal indicating two or more reference points for each cylinder, and outputs a plurality of reference points by recognizing the slit with a photoelectric pickup. It is configured to be able to.

Further, in the case of such a configuration, the time width from the selected measurement start point (reference point) to the ignition timing may not be able to obtain a sufficient energizing time for accumulating energy in the ignition coil. Therefore, in this case, the energization time (TDWELL) was given priority.

In the case of a large rotation increase such that a predetermined measurement start point close to the top dead center shifts to the advance side from the set energization start point, the shifted measurement start point position is used as the energization start point. And an ignition signal is generated after a set energization time.

Further, in the fuel injection timing control method and apparatus, the same control can be performed by regarding the fuel injection start point as the ignition timing.

[0014]

According to the present invention configured as described above, when the advance value is close to the top dead center, the measurement start point on the side close to the top dead center can be selected. Since the time can be shortened, and thus the possibility of the rotation speed fluctuation during this period can be reduced, a time-based ignition timing control method and apparatus for an internal combustion engine with less error can be obtained.

Further, the ignition timing control can be performed by simply modifying the sensor, for example, increasing the number of slits, or adding a circuit that uses the trailing edge in addition to the leading edge to another reference point signal to the slit detection circuit. A sensor compatible with the device is obtained. In addition, since the function of the energization time priority control is provided, there is no possibility of a misfire due to insufficient ignition energy.

Further, in the case of a rapid increase in the rotation, not only the movement of the ignition timing measurement point but also the energization start point can be moved, so that unnecessary retardation in the case of a rapid increase in the rotation can be suppressed.

Further, in the fuel injection control, the injection start point is hardly affected by the rotation fluctuation, so that the fuel is not injected at a timing shifted from the intake stroke. Further, the injection control can be performed in accordance with the opening / closing timing of the intake valve.

[0018]

Embodiments will be described below with reference to the drawings.
FIG. 2 shows a REF signal and a timing such as a fuel injection timing and an ignition time for a stroke of the four-cylinder engine.

The REF signal is a BT signal corresponding to each cylinder.
Rising signal of D.C.85 ° and B.T.D.C.15 °
A reference signal formed from the falling signal and a rising signal of B.T.D.C.5 ° for discriminating one cylinder and an A.T.D.C.
5 of the cylinder discrimination signal formed from the 10 ° falling signal
It is formed of individual pieces. The disadvantage of the method of setting the ignition timing using the REF signal will be described with reference to FIGS. FIG. 3 shows the setting of the ignition timing.
The ignition timing ADVT is equal to TREFL at the low timing of the REF signal.
, And CRSET, and in this system, 85 °, is used, and is calculated by the following equation.

[0020]

(Equation 1)

The calculated ADVT is a rising signal 85
° is set as a reference. Therefore, when the rotational speed is stable, a predetermined ignition timing can be obtained. However, if a rotational fluctuation occurs, an error occurs between the set ignition timing and the actual ignition timing. FIG. 5 shows an error in the ignition timing between when the rotation is increased and when the rotation is decreased. When the rotation speed is increased, the ignition speed is increased compared to when the ignition timing is set, so that the rotation speed is increased. Therefore, an error on the delay side occurs with respect to the calculated ignition timing because TDC comes earlier. . Conversely, when the number of rotations decreases, an error occurs on the advance angle side because the arrival of TDC is delayed. This error is shown in FIG. The error increases with distance from the ignition timing setting reference position of 85 °,
Also, the error increases as the fluctuation of the rotation speed increases.

FIG. 6 shows an example of an engine system applied to the present invention. In FIG. 6, air to be taken by the engine is taken in from an inlet 2 of an air cleaner 1 and a hot wire for detecting an intake flow meter. The air enters a collector 6 through a throttle valve body 5 in which a throttle valve for controlling the intake air flow rate is accommodated. Then, the intake air is distributed to each intake pipe 8 connected to each cylinder of the engine 7 and guided into the cylinder.

On the other hand, fuel such as gasoline is sucked and pressurized from a fuel tank 9 by a fuel pump 10, and then a fuel damper 11, a fuel filter 12, a fuel injection valve (injector) 13, and a fuel pressure regulator 14 are connected to a pipe. Supplied to the fuel system. Then, the fuel is regulated to a constant pressure by the above-described fuel pressure regulator 14, and is injected into the intake pipe 8 from a fuel injection valve 13 provided in the intake pipe 8 of each cylinder.

A signal representing the intake flow rate is output from the air flow meter 3 and input to the control unit 15.

Further, a throttle sensor 18 for detecting the degree of opening of the throttle valve body 5 is attached, and its output is also inputted to the control unit 15. A water temperature sensor for detecting the temperature of the engine is attached to the main body of the engine 7, and a signal from the sensor is input to the control unit 15.

Next, reference numeral 16 denotes a dist (distributor) having a built-in crank angle sensor and a reference angle signal RE representing the rotational position of the crankshaft.
F is output, and this signal is also input to the control unit 15.

Reference numeral 20 denotes an O ₂ sensor provided on the exhaust pipe.
In order to detect the stoichiometric air-fuel ratio, it is detected whether the air-fuel ratio is rich or thin with respect to the stoichiometric air-fuel ratio. This output signal is also input to the control unit 15.

As shown in FIG. 9, the main part of the control unit 15 receives, as inputs, signals from an MPU, a ROM, an A / D converter, various sensors for detecting the operating state of the engine, and the like. Executes arithmetic processing and outputs various control signals calculated as the arithmetic result,
A predetermined control signal is supplied to the fuel injection valve 13 and the ignition coil 17 to perform the fuel supply amount control and the ignition timing control.

FIG. 7 is a main sectional view of the crank angle sensor built-in dist 16 for generating the REF signal shown in FIG. A shaft 21 is rotatably inserted into the housing 22, and a single plate 23 and a rotor head 24 for distributing high pressure to each cylinder are fixed to the shaft 21. The single plate 2
3, a signal detection device 25 is arranged. The cap 26 is provided with a socket 27 to which a cord for supplying electricity to each ignition plug is connected and a socket 28 to which a cord for leading high voltage from the ignition coil 17 is connected. The ignition timing is controlled by sending a signal to the power transistor of the ignition coil 17.

FIG. 8 shows the shape of the single plate 23, in which two types of slits are provided as shown in the figure, and when these slits pass through the portion A having the light emitting portion and the light receiving portion shown in FIG. A REF signal as shown in FIG. 2 is generated.

Next, the ignition timing control method of the present invention having the above-described configuration will be described.

FIG. 1 is a diagram showing the present invention. In the system employing the present invention, the REF signal is supplied to the rising signal of BTDC85 ° and the BTDC15 for each cylinder.
A falling signal of ゜ is generated. As shown in FIG. 13, the basic ignition timing in the system employing the present invention is the basic pulse width TADVP and the engine speed TADVN.
MAP. This ignition timing is an optimal value from the viewpoint of output and drivability under each operating condition.
It is stored in the OM. The hatched portion in the drawing is a region where the ignition timing is ahead of BTD C15 °, and the region without the hatching is a region where it is later than BTD C15 °. In Figure 1, the pattern I is Ah of the oblique line 13
The pattern II sets the ignition timing in the region
3 shows a method of setting the ignition timing in an area without oblique lines. That is, in the pattern I, the ignition timing is BTDDC8.
5 ADVT based on the 1st reference ignition position signal

[0033]

(Equation 2)

Here, CRSET = 85 ° Set ignition timing = 20 ° Calculated and set by the above equation (Equation 2).

In the pattern II, ADVT 'is set based on the second reference ignition position signal of BTC 15 °.

[0036]

(Equation 3)

Here, CRSET = 85 ° Set ignition timing = 10 ° Calculated and set by the above equation (Equation 3).

Further, as another embodiment of the present invention, when the set ignition timing is 10 °, the first reference ignition position signal is used as a base point.

[0039]

(Equation 4)

There is a method of calculating by the above equation (Equation 4).

As a result, the same result as the above-mentioned pattern II can be obtained, but the accuracy is slightly lower.

As described above, the reference ignition position signal is switched according to the value of the basic ignition timing.

The switching of the reference position signal has been described with reference to the map value of the basic ignition timing. However, in an actual system, the basic ignition timing is corrected by the cooling water temperature, or the correction is made at the time of fuel cut. In addition, since the correction is added depending on the operating conditions, the reference ignition position signal is switched based on the final value of the ignition timing to which these corrections have been added. The calculation of TREFL and TREFH is obtained by proportional calculation from the required time from the 85 ° point to the next 85 ° point as described in the conventional example.

Next, the present invention will be further described with reference to flowcharts.

FIG. 10 shows a method of setting the ignition timing, and FIG.
Fig. 12 shows a method for calculating the ignition timing setting time, and Fig. 12 shows a flowchart for setting the ignition timing setting time.
A method for setting the ignition timing will be described with reference to FIG.
In step 101, the engine speed and the fuel injection amount are read. In step 102, the ignition timing is searched from the map of the ignition timing based on the engine speed and the fuel injection amount, and the search value is stored in step 103.

Next, a method of calculating the ignition timing set time will be described with reference to FIG. REF at step 201
Identify signal edges (rising, falling). At step 202, the ignition timing is read.
In step 3, the energization start timing T ₁ is set, and
At 4, the time between the rising signal of BTC 85 ° from the falling signal of BTC 15 ° of the REF signal is measured, the ignition timing setting time is calculated, and ADVT is calculated. You. At step 206, the energization start timings T ₁ and R
The rising edge of the EF signal B.T.D.C85 ° and the B.T.C.
D. Compare TREFH between falling signals of 15 °,
When the energization start timing T ₁ is smaller than TREFH, T ₁ <TREFH (at the time of the IGN signal ABC in FIG. 14)
Uses the ADVT calculated in step 204. TR
If large energization start timing T ₁ than the EFH T ₁
≧ TREFH (at the time of the IGN signal DE in FIG. 14) is compared with (CRSET-ADV) and 70 ° in step 207, and when it is smaller than 70 ° (CRSET-ADV)
If ≦ 70 °, energization is started immediately in step 208, and in step 209, ADVT ′ is reset as TDWL = TDWL.
In step 207, (CRSET-ADV) and 70 °
Are compared, when the angle is larger than 70 ° (CRSET-A
DV)> 70 ° is the BT of the REF signal in step 210
The time between the rising signal of B.T.D.C.15 ° is measured from the rising signal of D.C85 °, the ignition timing set time is calculated, and ADVT ′ is calculated. In step 211,
ADVT 'and TDWL are compared, and ADVT' ≦ TDWL
If so, immediately energization is started in step 208 and step 20
At 9, reset as ADVT '= TDWL. ADV
If T ′> TDWL, ADVT′−T in step 212
'Seek, conduction start timing T ₁ at step 213' conduction start timing T ₁ from DWL to set again. In Step 205, Step 204, Step 209,
Step 213: calculated ignition timing setting time ADVT, A
DVT 'is stored.

Next, referring to FIG. 12, the ignition timing setting time is set in step 301, and if it is larger than BTC 15 °, as shown in pattern I of FIG. .C85 ° rising (falling) signal to A
DVT is set. If the B.T.D.C. is smaller than 15 °, the B.D.
AD from the falling (rising) signal of TDC15 °
VT 'is set.

Next, a method of calculating the ignition timing set time will be described with reference to FIG. In step 201, a search value of the ignition timing is read. In step 202, an ignition timing determination reference position is set. Here, BTDC15 °
If it is larger, the process proceeds to step 203. Step 20
3 measures the time between the REF signal BTC 15 ° falling signal and the REF signal BTC 85 ° rising signal (TREFL), and calculates the ignition timing setting time. Then, the ADVT is calculated. Also, BTD
If it is smaller than C15 °, the process proceeds to step 204, at which the rising edge signal (TTC85 °) of the REF signal BTDC85 °
REFL) is measured, the ignition timing set time is calculated, and ADVT is calculated. In step 205, the ignition timing set time ADVT calculated in steps 202 and 203 is stored. Next, according to FIG. 12, the ignition timing setting time is set in step 301, and if it is larger than BTDDC15 °, ADVT is set from the rising signal of BTD85 ° of the REF signal. You. If B.T.D.C is smaller than 15 °,
ADVT from BTDC15 ° falling signal of REF signal
Is set.

Although the control of the ignition timing has been described in the present embodiment, the same concept can be used for the fuel injection control. In this case, the falling point (injection end position) of the injection pulse is calculated based on the reference pulse rising point immediately before the injection cylinder, and the remaining time obtained by subtracting the fuel injection pulse width obtained from the operating state of the engine is calculated. This indicates the injection start point. Similar control can be performed by regarding this starting point as the above-described ignition timing.

[0050]

As is apparent from the above description, according to the present invention, a plurality of ignition timing measurement start reference points are provided before the top dead center corresponding to each cylinder, and the ignition timing is determined by the value of the ignition timing. CP
A reference point that reduces the difference between the calculated value of U and the actual ignition timing can be selected, and the ignition timing can be set from the reference point.
Therefore, there is an effect that a predetermined ignition timing can be obtained even if the rotation of the engine fluctuates.

[Brief description of the drawings]

FIG. 1 is a diagram showing a method for setting an ignition timing according to the present invention.

FIG. 2 is a diagram showing a timing chart such as ignition timing.

FIG. 3 is a diagram showing a conventional method for setting an ignition timing.

FIG. 4 is an ignition timing error caused by a conventional ignition timing setting method.

FIG. 5 is a diagram showing a problem in the related art.

FIG. 6 is a configuration diagram showing an example of an engine system.

FIG. 7 is a main cross-sectional view of a crank angle sensor built-in dist that generates a REF signal.

FIG. 8 is a diagram showing a single plate.

FIG. 9 is a block diagram of a control unit.

FIG. 10 is a flowchart showing a method for setting an ignition timing.

FIG. 11 is a flowchart illustrating a method for calculating an ignition timing set time according to the present invention.

FIG. 12 is a flowchart for setting an ignition timing setting time.

FIG. 13 is an ignition control map.

FIG. 14 is a diagram showing considerations for improvement measures of the present invention.

FIG. 15 is a diagram showing the effect of the present invention.

FIG. 16 is a detailed flowchart of the embodiment of the present invention.

[Explanation of symbols]

Reference numeral 15: Control unit, 16: Dist with built-in crank angle sensor, 17: Ignition coil, 19: Power transistor, 21: Shaft, 22: Housing, 23: Single plate, 24: Rotor head, 25: Signal detection device, 26: Cap , 27, 28 ... socket.

────────────────────────────────────────────────── ─── Continued on the front page (51) Int.Cl. ⁷ Identification code FI F02P 7/073 F02P 7/073 17/04 5/15 C 17/00 C (72) Inventor Hosokurai Shigenori Katsuta, Ibaraki 2477, Kashima-Yatsu, Takaba 3 Within Hitachi Automotive Engineering Co., Ltd. (56) References JP-A-3-145571 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F02P 5/15 F02D 41/34 F02D 43/00 301 F02D 45/00 362 F02P 7/073 F02P 17/04

Claims (1)

(57) [Claims] 1. A map storing ignition timing advance values according to the operating state of an engine, determining a measurement start point of ignition timing from a plurality of reference points provided before the top dead center of each cylinder; Measuring means for measuring a time width corresponding to the advance angle value read from the map from the measurement point; energizing control means for determining a starting point for energizing the ignition coil of the following cylinder from the ignition timing of the preceding cylinder; Control apparatus for controlling an internal combustion engine, comprising: an energization start point control means for preventing the energization start point from being set closer to the top dead center than a specific reference point close to the top dead center among the reference points. .