JPS58190572A - Ignition timing controller - Google Patents

Abstract

PURPOSE:To obtain an idle speed always coincident with a target speed, by setting ignition timing in accordance with a deviation between the target speed and an actual speed at idling. CONSTITUTION:During operation in an arithmetic device 1, ignition giming stored to a ROM4 is read from a speed signal obtained from an output of a crank angle sensor 6 and an intake amount signal from an intake air amount sensor 7 and stored to a RAM5. Then under an idle operation condition in which a car speed sensor 10 detects a low car speed further with an actual rotary speed in a preset value or less, a deviation DELTAN between the actual rotary speed and a target rotary speed is calculted to add a proportional amount DELTANp, integrating amount DELTAN1 and differentiating amount DELTAND and calculte a corrective coefficient. Then this coefficient A is multiplied or added to said ignition timing to calculate actual ignition timing and control an ingition device 12 on the basis of this ignition timing.

Description

[Detailed description of the invention] The present invention relates to an ignition timing control device for an internal combustion engine.

In particular, the present invention relates to a device for controlling idle rotation speed by controlling ignition timing.

Conventional ignition timing control devices include, for example, a system in which the ignition timing, which is preselected according to the intake air line and rotational speed of the engine, is read out for each ignition stroke, and the ignition timing is controlled according to that value. be.

However, the conventional ignition timing control device as described above controls the ignition timing so as to optimize the combustion state (for example, maximize the generated torque).

The purpose was not to control the rotational speed.

However, if the rotational speed fluctuates due to disturbances or changes over time during idling, stability may deteriorate, and if the idle rotational speed decreases due to changes over time, the two engines are likely to stall.

In order to solve the above problem, the upstream and downstream parts of the throttle valve in the intake pipe are connected by a bypass pipe, and a flow control valve is provided in the middle of the bypass pipe to control the flow control valve during idle link. A device is used that controls the idle rotation speed to a constant value by controlling the amount of air flowing through the bypass pipe.

However, in the above-mentioned apparatus, there is a problem that the apparatus is complicated and expensive because it is necessary to specially provide a bypass pipe, a flow control valve, etc.

The present invention has been made to solve the two problems, and by controlling the idle rotation speed by controlling the ignition timing, the idle rotation speed is maintained at a constant value by an extremely inexpensive means. In order to achieve the above-mentioned object, the present invention aims to provide an ignition timing control device capable of controlling the ignition timing.

By focusing on the fact that the rotation speed during idling changes depending on the ignition timing, and setting the ignition timing according to the deviation between the target rotation speed and the actual rotation speed during idling,
The idle rotation speed is configured to always match the target rotation speed.

The present invention has the feature that it can be realized at a very low cost because the idle speed can be controlled using only one ordinary electronically controlled ignition device.

The present invention will be described in detail below based on the drawings.

FIG. 1 is a diagram showing an embodiment of the present invention.

In FIG.
.

central processing unit)2. Input/output interface 3. It is composed of a microcomputer consisting of ROM 4, RAM 5, etc.

Further, the crank angle sensor 6 outputs a unit angle pulse S1 every time the crankshaft rotates by a unit angle (for example, 1°), and also outputs a unit angle pulse S1 every time the crankshaft rotates by a unit angle (for example, 1°). (number) A reference angle pulse S2 is output every time it rotates.

Further, the intake air break sensor 7 outputs an intake air amount signal S3 corresponding to the intake air break of one engine.

The mataslo sotor sensor 8 outputs a throttle signal S4 according to the throttle valve opening.

Further, the temperature sensor 9 outputs a temperature signal S5 corresponding to the engine cooling water temperature.

The vehicle speed sensor 10 also outputs a vehicle speed signal S corresponding to the vehicle speed.
Outputs 6.

In addition, the starter switch 11 is activated when the starter motor is activated (
During cranking), a start signal S7 is output.

On the other hand, the ignition device 12 includes an N source 169, an ignition coil 14° transistor 15. Dis) Consists of an IJ computer 16 and spark plugs 17A to 17F. When the ignition signal S8 is given from the arithmetic unit 1, the ignition coil 14
The high voltage is generated by the distributor 16, and the high voltage is then applied to the spark plug selected by the distributor 16 to ignite the spark plug.

Next, the ignition calculation within the calculation device 1 will be explained.

FIG. 2 is a flowchart showing the entire process of ignition calculation.

In FIG. 2, first, at P, the start signal S7 is
Based on this, it is determined whether or not it is cranking time.

If Pl is YES, the process goes to P2 and calculates the ignition timing (for example, a predetermined value) during cranking.

If NO in P2, the process goes to P3, and it is determined from the throttle signal S4 whether the throttle valve is fully closed or not.

If YES in P3, go to P4 and calculate the ignition timing at idle.

This is done, for example, by searching for a value stored in the ROM 4 in advance as a value corresponding to one rotational speed, as shown in FIG. 5(3).

Next, in P5, a correction is made to keep the rotational speed constant.

Note that details regarding this part will be described later.

- If the answer is No in P3, go to P6 and divide the ignition timing during non-idling.

For example, as shown in FIG. 6 (13), this is retrieved from values stored in the ROM 4 in advance as values corresponding to the rotational speed and the amount of intake air.

Note that the rotational speed of the engine is constant for a certain period of time (for example, 125m5).
) can be determined by counting the number of unit angular pulses S1 input within the range. Further, the intake air h: is determined based on the intake air amount signal S3.

Next, in P7, the calculated ignition timing is stored in a predetermined location in the RAM 5.

Of the calculations shown in FIG. 2 above, the portions excluding P5 are the same as those on the conventional ignition timing side.

Next, FIG. 4 is a flowchart of the calculation of P5 mentioned above.

This calculation is repeated, for example, every time the engine rotates once.

In FIG. 4, based on the judgment of P9 and P1□, the idle rotational speed is changed only when the vehicle speed is low (e.g., 8-outer or less) and the actual rotational speed N is less than the set value Nc (e.g., so ORPM). Perform control to keep it constant.

If one of the above two judgments is NO.

Since this is not a true idle link time, the correction coefficient A is set to a constant value A' in PI3. In P21, the ignition timing is calculated by multiplying or adding A' to the value obtained in P4 of Fig. 2 above. .

When both P9 and pH are YES, in other words, when it is a true idle link, it goes to IP+3 and the actual rotation speed N(
The deviation ΔN=NS-N between the engine's actual rotational speed) and the target rotational speed Ns (the target value of the idle rotational speed) is calculated.

Next, from P+4 to P16, a correction corresponding to the deviation ΔN described above is performed. In the embodiment of FIG. 4, PID (proportional).

This example shows a case where the product (7 minutes, differential) control is performed.

At step P+4, the proportional portion ΔNP is calculated.

The proportional portion ΔNP is the value obtained by multiplying the deviation ΔN by the proportionality constant KP,
That is, ΔNP=KP·ΔN.

The integral ΔN is the integrated value ΔNo - ΔNO + - ΔN, that is, the value obtained by adding the current deviation value to the previous integrated deviation value is the current integrated value, and the integrated value ΔNo is multiplied by the constant of integration. The value is 6, that is, ΔNT=Kr・ΔNo.

The differential ΔND is the previous deviation ΔN-1 and the current deviation ΔN
Let the difference from
D-JN'.

Next, at P+7, add the above proportional part ΔNP, integral part ΔN+, and differential part ΔND, and the correction coefficient A=ΔN, l-ΔN■+
Calculate ΔND.

In addition, in the above calculation, it is calculated as Δl'J = l'Js - N, so when ΔN is positive, the proportional portion JNP becomes a positive value, advances the ignition timing, and increases the actual rotation speed N. direction. Further, when the integrals ΔN, r and the differential ND have positive values, the ignition timing is advanced, and when they are negative, the ignition timing is delayed. The relationship between rotational speed and ignition timing during idle link is shown in Figure 6, and BTDC4
Near 0°, that is, MBT (minimum 5par
kadva, nce for best torque)
Up to 9, advancing the ignition timing will increase the rotation speed.

Next, in P18, the ignition timing is determined by multiplying or adding the correction coefficient A to the ignition timing value obtained in P4 of FIG.

Next, at P+9, it is determined whether the value of the 9th ignition timing is within a predetermined upper and lower limit range.

If P+9 is NO, go to P2O, and if the ignition timing is larger than the above range, it is limited to the upper limit value, and if it is smaller, it is limited to the lower limit value.

If PI3 is YES, the ignition timing value of P18 is output.

The ignition timing set as described in 1 above is stored at a predetermined location in the RAM 5 at P7 of the 2nd IN.

The reason for setting the above-mentioned P19 and P2O limits is as follows.

That is, as can be seen from the characteristics shown in Figure 6, one ignition timing is M
In the range of BT, that is, BTDCO0 to 4o0, the rotational speed increases as the ignition timing is advanced by two. However, M.B.T.
If the angle is further advanced, the 5th rotation speed tends to decrease.

Therefore, when controlling the rotation speed by ignition timing, the value of 1 ignition timing should be set to BTDC00~4o0 (engine's 1
It is necessary to limit the range to the vicinity (varies somewhat depending on the Φ class).

The limits for PI3 and P2O are set to keep the 7 ignition timings within the above range, and the upper limit value of PI3 and P2O is set to, for example, BTDC40°, and the lower limit value is set to, for example, BTDCOo.

Next, as can be seen from the characteristics in Figure 6, the rotational speed that can be controlled by one ignition timing is about 1100RP (B
If the engine speed is lower than TDCo°, that is, if the angle is retarded, the rotation speed can be lowered even further, but this is not practical because the combustion characteristics become stratified), and the rotational speed cannot be changed very widely.

In the rotational speed control during normal idle link, which is the object of the present invention, during the above-mentioned level of control (for example, the target rotational speed is
5 ORPM (650 ± 5 ORPM) is sufficient, but when the rotation speed is set to a much higher value than during normal idle link, such as during warm-up, control becomes difficult. turn into.

Therefore, the engine is configured to detect the on-state state of the engine from the temperature signal S5 of the temperature sensor 9 shown in FIG. It's okay.

Next, FIG. 5 shows a circuit that outputs an ignition signal S8 corresponding to the ignition timing calculated as described above.

In FIG. 5, 18 is a register and 19 is a counter.

20 is a digital comparator, and these circuits are connected to the first
It is included in the input/output interface 3 in the figure.

The counter 19 outputs a reference angle pulse S at a predetermined angle (for example, BTDC7oo) before the top dead center of the compression stroke of each cylinder.
2, and the angle pulses SL input thereafter are counted.

The register 18 reads the ignition timing value stored in the RAM 5 when the reference angle pulse S2 is input, holds and outputs the value.

The comparator 20 compares the value of the register 18 and the count value of the counter 19, and outputs the ignition signal S8 when the two match.

As explained above, according to the present invention, the 9 ignition timings are controlled during idling so that the actual rotation speed matches the target rotation speed, so that the idle rotation speed remains constant. Keep the value.

Improved stability. It is still possible to maintain the idle rotation speed at a constant value even with changes over time. Therefore, there is no risk of stalling due to fluctuations or decreases in the rotational speed, so the idle rotational speed can be set to a low value, thereby improving fuel efficiency during idling.

There is still a system that centrally controls fuel injection, exhaust recirculation, etc. using a microconbeater.

Since the arithmetic device 1 and the sensors 6 to 11 shown in FIG. 1 are all provided, the present invention can be realized simply by changing the arithmetic program, which has the effect of being extremely inexpensive.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of an embodiment of the present invention, Fig. 2 is an embodiment of a flowchart showing the entire process of ignition timing characteristics, Fig. 6 is an example of ignition timing characteristics, and Fig. 4 is an ignition timing characteristic diagram. FIG. 5 is an example of a flowchart of timing correction calculation, FIG. 5 is an example of an ignition signal output circuit, and FIG. 6 is a diagram of the relationship between rotational speed and ignition timing. Explanation of symbols 1... Arithmetic unit 2... CPU 6... Input/output interface 4... ROM 5... RAM 6...
・Crank angle sensor 7... Intake air amount sensor 8...
- Throttle sensor 9...Temperature sensor 10...Vehicle speed sensor 11...Starter switch 12...
Ignition device 16... Power source 14... Ignition coil 15... L. Distributor 17A-17F... Spark plug 18... Register 19... Counter 20.
... Comparator attorney Junnosuke Nakamura Figure 1 Figure 1 f2 Figure

Claims (1)

[Claims] 1. An ignition timing control device that controls ignition timing according to the operating state of an internal combustion engine, comprising means for detecting the actual rotational speed of the internal combustion engine, means for detecting an idle link state, and an idle link. and a deductive means for controlling the ignition timing so as to eliminate the deviation between the actual rotational speed and the target rotational speed, and controlling the ignition timing so as to keep the rotational speed constant during idling. Timing control device. 2. A patent characterized in that the above-mentioned means is configured to set a predetermined upper limit value and lower limit value in the range of change of ignition timing, and to limit one ignition timing to a value within the range. An ignition timing control device according to claim 1. 5 The calculation means is configured to control the ignition timing so as to eliminate the deviation between the actual rotation speed and the target rotation speed only when the internal combustion engine is in the idle state and is not in the warm-up state. An ignition timing control device according to claim 1 or 2, characterized in that the ignition timing control device is an ignition timing control device according to claim 1 or 2. 4. The calculation means adds at least one or more of a proportional component proportional to the deviation between the actual rotational speed and the target rotational speed, an integral obtained by integrating the deviation, and a differential obtained by differentiating the deviation. 2. The ignition timing is determined by multiplying or adding the correction coefficient determined in advance to the ignition timing set in advance according to the rotational speed. The ignition timing control device according to any one of the above.