JP3104526B2 - Apparatus and method for controlling ignition timing of 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 an ignition timing control device for an internal combustion engine and a control method thereof.

[0002]

2. Description of the Related Art A conventional ignition timing control device for an internal combustion engine includes:
Generally, an average value of the ignition timing of the internal combustion engine at which the output is maximized and the fuel consumption rate is minimized is determined from the rotation speed of the internal combustion engine and the intake pressure of the intake pipe. However, the ignition timing at which the maximum output is generated changes due to manufacturing variations or aging of the internal combustion engine. Japanese Patent Application Laid-Open No. 57-35156 discloses an ignition timing control device that optimally controls the ignition timing regardless of such variations during manufacturing or aging of the internal combustion engine.

[0003] When an internal combustion engine is operated in a steady state for a predetermined period, a detection signal indicating the rotation speed or shaft torque of the internal combustion engine before the predetermined period or an operating state of the internal combustion engine related thereto is provided. The direction of the ignition timing at which the rotational speed or the torque of the internal combustion engine increases is determined by comparing the same detection signal after a predetermined period has elapsed, and the ignition timing correction amount is determined from these detection signals to optimize the ignition timing. Controlling. Here, the steady state means, for example, a state in which a change amount of the internal combustion engine rotation speed at a predetermined time interval is obtained and the change amount is within a certain range.

[0004] In some cases, the ignition timing of the internal combustion engine is optimally controlled based on the rotational speed of the internal combustion engine. In this method, the direction of the optimal ignition timing is determined based on the direction of change of the internal combustion engine speed when the ignition timing is advanced or retarded, and the ignition timing is manipulated with a constant correction amount to gradually achieve the optimal ignition timing. Approaching.

[0005]

However, in such a conventional ignition timing control device, for example,
The system disclosed in Japanese Patent No. 35156 inputs not only the rotational speed of the internal combustion engine but also the intake negative pressure of the intake pipe as operation information of the internal combustion engine, and obtains a correction amount of the ignition timing from the operation information to determine the current ignition timing. Corrections have been made to the timing. Furthermore, since the correction amount of the ignition timing is obtained from the storage device using the rotation speed and the intake negative pressure as addresses, there is a problem that the control is complicated and the storage device is required.

On the other hand, in the above-described ignition timing control device that determines the ignition timing only by the rotation speed of the internal combustion engine, it is difficult to search for the optimum ignition timing when the operating state of the internal combustion engine changes frequently. It is difficult to search for the optimum ignition timing because it is easily affected by disturbances such as throttle operation and road surface conditions.Since the ignition timing changes in the advance and retard directions even near the optimum ignition timing, the ignition timing There is a problem that it is not stable.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and it is an object of the present invention to provide an ignition timing control apparatus for an internal combustion engine and a control method for quickly searching for an optimum ignition timing and holding the ignition timing stably. It is in.

[0008]

SUMMARY OF THE INVENTION To accomplish the above object ignition timing control device according to claim 1 an internal combustion engine according to the present invention, a rotational speed measuring device for measuring the rotational speed of the internal combustion engine, wherein
And steady-state detecting means for detecting the steady state of the internal combustion engine, before
The steady state detecting means determines that the internal combustion engine is in a steady state.
When it is constant, the measured by the previous SL rotational speed measuring instrument
If the ignition timing is set according to the rotation speed of the internal combustion engine
In both cases, the search correction calculated according to the change amount of the rotation speed
This is for advancing the ignition timing by an amount.
Ignition timing after advance correction and ignition timing before advance correction
Multiplied by a predetermined coefficient to the amount of change in the number of revolutions of the internal combustion engine.
The next search for the ignition timing after the advance correction by shifting
A correction amount is set, and the next search correction amount is set after the advance correction.
Before the further advance correction to the ignition timing, thereby obtained
The engine speed of the internal combustion engine is compared with the engine speed after the advance correction.
If the difference is equal to or smaller than a predetermined value, the ignition timing is advanced.
Calculation processing for searching for a predetermined ignition timing by ending
And a processing device. Preferably, the coefficient of the ignition timing control device for an internal combustion engine according to the present invention is a coefficient approximating a change characteristic of the rotational speed with respect to the ignition timing.

[0009]

[0010]

[0011]

According to the ignition timing control device according to claim 1 Symbol placement of an internal combustion engine of the operation and effect of the present invention, it is possible to search easily and quickly predetermined ignition timing regardless of the operating state of the internal combustion engine.

[0012] According to the ignition timing control device according to claim 2 Symbol placement of an internal combustion engine of the present invention, since setting the ignition timing correction amount by a factor approximating the characteristics of the rotational speed, the predetermined ignition timing and the current ignition timing When the difference between the predetermined ignition timing and the current ignition timing is small, the correction amount also becomes small, so that the predetermined ignition timing is searched for more quickly. And can be stably held.

[0013]

An embodiment of the present invention will be described with reference to the drawings.
FIGS. 1 and 2 show an ignition timing control apparatus for an internal combustion engine (hereinafter referred to as an "internal combustion engine") according to an embodiment of the present invention.
Shown in The ignition key 11 shown in FIG. 1 is a switch for cutting off the power supply between the power supply 12 and the ignition coil 13. When the ignition key 11 is turned on, the control device 14 cuts off the supply of the voltage applied from the power supply 12 to the ignition coil 13, and a high voltage is generated in the ignition coil 13. The distributor 15 distributes the high voltage generated by the ignition coil 13 to each cylinder. Distributor 15
Has a rotation angle sensor for generating a reference signal at a predetermined timing of each cylinder. The input terminals 16 and 17 are connected to a throttle opening sensor or a pressure sensor necessary for detecting the acceleration / deceleration state of the engine as necessary, and a signal indicating the acceleration / deceleration state is sent to the control device 14.

As shown in FIG. 2, the control device 14 comprises an 8-bit microprocessor 21, an energizing circuit 22, a waveform shaping circuit 23, an input circuit 24, and a power supply circuit 25. The microprocessor 21 performs optimal ignition timing control according to the operating state of the engine. The energizing circuit 22 is operated by the ignition coil 13 according to an instruction from the microprocessor 21.
Is turned off. The waveform shaping circuit unit 23 is a circuit for receiving a rotation signal from a rotation angle sensor provided in the distributor 15. The input circuit 24 is a circuit for inputting an operation state detection signal sent from various sensors external to the control device 14, such as a throttle opening sensor or a pressure sensor. The power supply circuit section 25 supplies power such as a battery to each section.

When the control device 14 is manufactured, a reference set value of the ignition timing according to the engine speed is previously stored in the built-in ROM of the microprocessor 21 in accordance with the engine characteristics as shown in a graph 302 of FIG. . As the reference set value, for example, an ignition timing in a fully opened state of a throttle valve of the engine is set. However, as shown in a graph 301 in FIG. 3, for example, the optimum ignition timing of the engine changes due to engine manufacturing variations, engine aging, and the like. It is necessary to approach the value of the optimal ignition timing of the engine.

FIG. 4 shows the operation of the ignition timing control device of this embodiment.
This will be described with reference to FIG. The amount of change in torque with respect to the ignition timing of the engine changes depending on the operating conditions and load conditions of the engine. However, the relationship between the ignition timing and the number of revolutions of the engine is not so affected by the operating conditions and load conditions of the engine, and can be approximated by the graph 303 in FIG. When the ignition timing of the engine is changed in the advance direction, the rotation speed of the engine increases, and after the ignition timing A, the rotation speed of the engine decreases. That is, the ignition timing A at which the engine speed becomes maximum becomes the optimal ignition timing. FIGS. 7 and 8 are flowcharts of a control routine for calculating the optimum ignition timing correction amount AMBT for obtaining the optimum ignition timing by correcting the above-described reference set value. Since the ignition timing calculation processing routine for calculating the ignition timing from the obtained optimum ignition timing correction amount AMBT is not directly related to the present invention, the description is omitted.

Hereinafter, a control method of a control routine for obtaining an optimum ignition timing by dividing into (1) determination of a steady state or an acceleration / deceleration state, (2) processing in a steady state, and (3) processing in an acceleration / deceleration state will be described. I do. (1) Determination of Steady State or Acceleration / Deceleration State The optimal ignition timing control routine is called every time before the ignition timing calculation processing routine for calculating the ignition timing of the engine. It is determined in step 102 whether the engine is operating in a steady state. If the engine is in a steady state, the process proceeds to step 103. If the engine is in an accelerating / decelerating state, the process proceeds to step 105. Here, whether the vehicle is in the steady state or not is determined by the steady state flag set in the acceleration / deceleration determination processing routine shown in FIG.

In step 202, the current engine speed N
Measure E. In step 203, a difference DNE between the current engine speed NE and the engine speed NE _old measured when the previous acceleration / deceleration determination processing routine was called is determined, and NE is substituted for NE _old . In step 204, D
The magnitude of the absolute value DNEO of NE and the predetermined rotational speed difference KDNE are compared, and if DNEO is smaller than KDNE,
That is, if the change in the rotational speed is small, the process proceeds to step 205, and if the DNEO is equal to or larger than KDNE, that is, if the change in the rotational speed is large, the process proceeds to step 207. Step 205
Then, it is determined whether or not the steady state is continuing. If the steady state is continued, this routine is ended. If the steady state is not continued, the steady flag is turned on. That is, the steady state of the engine indicates a state in which the change in the engine speed is small within a certain period. In step 207, it is determined whether DNE is positive or negative. When DNE is negative, that is, when the rotational speed is in a deceleration state in a decreasing direction, the process proceeds to step 208, and when DNE is positive,
That is, when the rotational speed is in the acceleration state in the increasing direction, step 21 is performed.
Go to 0. In step 208, it is determined whether or not the deceleration state is continuing. If the deceleration state is continuing, this routine is ended. If not, the deceleration flag is turned on and this routine is ended. In step 210, it is determined whether or not the acceleration state is continuing. If the acceleration state is continuing, the routine is terminated. If not, the acceleration flag is turned on and the routine is terminated.

(2) Processing in Steady State Further, processing in the steady state will be described separately for determination of rotation measurement timing, determination of completion of ignition timing search, and calculation of the next ignition timing. Determination of Rotation Measurement Timing In step 103 shown in FIG. 7, it is determined whether the search for the optimum ignition timing has already been completed, and if the search has been completed, this routine ends. If the search for the optimum ignition timing has not been completed, the routine proceeds to step 104. Step 104
Then, it is determined whether the optimum ignition timing is being searched. If the search is being performed, the process proceeds to step 108. If the search is not being performed, that is, if the search is the first search, the process proceeds to step 107. In step 107, a predetermined initial value is substituted for the search correction amount SMBT, and in the next step 112, a search flag indicating that a search is being performed is turned on, and the routine proceeds to step 116. In step 116, the optimum ignition timing correction amount AMBT is obtained by the following equation (1).

AMBT = AMBT + SMBT (1) When the process proceeds from step 112 to step 116, the AMBT at this time is zero.
The value of MBT is directly substituted into AMBT. In the next step 118, the current engine speed NE is substituted for the engine speed NEO before correction, and the ignition number counter C
MBTIG is cleared to zero and this routine ends.
In step 108, it is determined by the ignition number counter CMBTIG whether or not the ignition has been performed a predetermined number of times at fixed time intervals. If the ignition has not been performed the predetermined number of times, this routine ends. If the ignition has been performed a predetermined number of times, the routine proceeds to the next step 110.

Determination of completion of ignition timing search In step 110, the current engine speed NE is measured. In the next step 111, the current engine speed N
Find the difference between E and the engine speed NEO before correction,
If the difference is equal to or less than the predetermined value, it is determined that the search for the optimum ignition timing has been completed, and the routine proceeds to step 114. If this difference is larger than the predetermined value, the process proceeds to step 113.

Calculation of Next Ignition Timing As shown in the following equation (2), the search correction amount SMBT is calculated by multiplying the difference between the current engine speed NE and the engine speed NEO before correction by a coefficient k. Ask. SMBT = (NE−NEO) × k (2) The coefficient k is a value obtained by approximating the characteristic of the engine speed with respect to the engine ignition timing in FIG. 4, and is the current engine speed NE and the engine speed before correction. By multiplying the difference from NEO by a coefficient k, the value obtained this time is set smaller than the search correction amount SMBT obtained last time. Further, since the search correction amount SMBT can be easily obtained from the equation (2), and the optimum ignition timing correction amount AMBT can be obtained from the search correction amount SMBT in the subsequent step 116, the processing of the microprocessor 21 in FIG. 2 is simplified. be able to. When the obtained search correction amount SMBT is larger than the predetermined correction value,
This predetermined correction value is substituted for the search correction amount SMBT. If the search correction amount SMBT is increased, the optimum ignition timing can be searched earlier. However, if the search correction amount SMBT is increased, the rotational speed also changes greatly. May be determined. In addition, if the ignition timing is largely changed in a state where the engine load is high, knocking occurs and the revolution speed changes suddenly, giving a shock to the occupant. By limiting the correction of the ignition timing of the engine within the range of the predetermined correction value, occurrence of knocking and an impact given to the occupant are prevented. In the next step 116, the optimum ignition timing correction amount AMBT is obtained by adding the search correction amount SMBT obtained in step 113 to the optimum ignition timing correction amount AMBT. Next step 118
Then, the current engine rotational speed NE is substituted for the engine rotational speed NEO before correction, the ignition number counter CMBTIG is cleared to zero, and this routine ends.

(2) At the time of acceleration / deceleration In step 105, it is determined whether the acceleration / deceleration state is continuing. If it is, the process proceeds to the next step 106, and if not, the process proceeds to step 109. Step 1
At 06, the predetermined value a is subtracted from the optimum ignition timing correction amount AMBT. The optimum ignition timing correction amount AMBT finally becomes zero by subtracting the predetermined value a, and the ignition timing of the engine becomes a value shown in a graph 302 of FIG. In step 109, the search completion flag and the search flag
F, the ignition count counter CMBTIG is cleared to zero, and this routine ends.

FIG. 6 shows a change in the ignition timing, a change in the engine speed, a change in the number of engine ignitions, and a change in the search completion flag due to the change in the ignition timing according to the above-described optimum ignition timing control routine. Ignited engine according ignition timing theta ₁ obtained by adding the optimal ignition timing correction amount AMBT the reference ignition timing indicated by the graph 302 in FIG. 3, the ignition count counter CMBTIG counts UP to each ignition. As shown in the graph 305 of FIG. 6, the engine speed there is a slight delay in the response even if ignition timing is advanced, the predetermined engine rotational speed N ₁ gradually rises. As shown in the graph 306, when the ignition count counter CMBTIG reaches a predetermined number of times S _1, calculates the following optimal ignition timing correction amount AMBT seek next ignition timing theta _2. Hereinafter, similarly, the ignition timings θ ₃ and θ _{3
4, θ 5} is required. After a predetermined number of ignitions S ₅ elapses, it determines the difference between the engine speed N ₅ and the rotational speed N ₄ falls within a predetermined range of the theta ₅ and optimum ignition timing, the graph 307
The search completion flag is turned on as shown in FIG.

In this embodiment, the search correction amount SMBT is obtained by multiplying the difference between the rotational speeds by the coefficient k, so that when the difference between the optimum ignition timing and the current ignition timing is large, the difference between the rotational speeds becomes large. Therefore, the ignition timing is largely corrected, and when the difference between the optimum ignition timing and the current ignition timing is small, the difference in the number of revolutions is small, so that the correction is made small. For this reason,
The optimum ignition timing can be quickly searched. further,
After the search for the optimum ignition timing, the search process is omitted until the acceleration / deceleration state is reached. The ignition of the engine is stably performed by the optimum ignition timing, and the search correction amount SMBT is obtained by a simple process. Processor 2
By reducing the load of the first arithmetic processing, the optimum ignition timing can be quickly searched and stably maintained even in the high engine speed range. Therefore, the optimum ignition timing can be searched in a short time even during a slight steady state occurring in the engine, and the stability of the ignition timing can be ensured near the optimum ignition timing. Further, even if the engine speed condition changes, the optimum ignition timing can be quickly searched.

In this embodiment, the optimum ignition timing is searched for in the advance direction, and the ignition timing when the difference between the engine speeds falls within a predetermined range is set as the optimum ignition timing. It is possible to search in the retard direction.
Further, since the minimum advance value (MTB) at which the maximum torque or the maximum rotational speed is obtained is originally a desirable value as the optimal ignition timing, the present invention uses the rotational speed change amount when searching from the retard side with respect to the optimal ignition timing. When the search is completed at the time when the value becomes smaller than the predetermined change value and the search is performed from the advance side, after the rotation speed change amount becomes smaller than the predetermined change value, the search is continued until the rotation speed change amount reverses. It is possible to set the ignition timing immediately before the amount of change in the rotational speed falls below the predetermined change value as the optimum ignition timing. Further, a knocking detection function is provided, and the search can be stopped when the occurrence of knocking is detected.

Further, in this embodiment, the acceleration / deceleration state and the steady state are determined from the engine speed. However, in the present invention, the engine operation state detection signal from the throttle opening sensor or the pressure sensor of the intake manifold is used to detect the engine operation. It is also possible to determine the acceleration / deceleration state and the steady state. Further, when the engine speed changes at such a rate that the acceleration / deceleration state cannot be determined after completion of the search for the optimum ignition timing, the optimum ignition timing cannot be searched in the present embodiment. Alternatively, a process may be added in which the optimum ignition timing is searched again every time a predetermined time elapses to confirm whether the optimum ignition timing has changed. Further, the search for the optimum ignition timing may be restarted when the rotation speed changes to a predetermined value or more instead of the predetermined time. Further, it is also possible to create a two-dimensional map of the engine speed and the intake pressure, and learn the ignition timing correction amount while updating the two-dimensional map with the ignition timing correction amount obtained at the corresponding address.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an ignition timing control device according to one embodiment of the present invention.

FIG. 2 is a block diagram illustrating an internal configuration of a control device according to the present embodiment.

FIG. 3 is a characteristic diagram showing a relationship between an optimum ignition timing and a reference ignition timing according to the embodiment.

FIG. 4 is a characteristic diagram showing a relationship between an engine ignition timing and a rotation speed.

FIG. 5 is an explanatory diagram showing a process of obtaining an optimum ignition timing from a relationship between an engine ignition timing and a rotation speed.

FIG. 6 is an explanatory diagram showing transition states of an engine ignition timing, a rotation speed, an ignition frequency, and a search completion flag in a process of obtaining an optimum ignition timing.

FIG. 7 is a flowchart illustrating an optimal ignition timing control routine according to the present embodiment.

FIG. 8 is a flowchart illustrating an acceleration / deceleration determination processing routine according to the present embodiment.

[Explanation of symbols]

 14 control unit 21 microprocessor (arithmetic processing unit)

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-62-276268 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F02P 5/15 F02D 45/00 312

Claims (2)

(57) [Claims] 1. A rotation speed measurement for measuring a rotation speed of an internal combustion engine.
And a steady state detecting means for detecting a steady state of the internal combustion engine
The steady state is detected by the steady state detecting means.
When determined, the rotation speed of the internal combustion engine measured by the rotation speed measuring device
The ignition timing is set according to
The ignition is performed by the search correction amount obtained according to the amount of change in the number.
The timing is to be advanced, and the point after this advanced correction
The internal combustion engine at ignition timing and ignition timing before advance correction
By multiplying the change amount of the rotation speed of Seki by a predetermined coefficient,
Set the next search correction amount of the ignition timing after the advance angle correction,
The next search correction amount is exposed to the ignition timing after the advance correction.
The rotation speed of the internal combustion engine and the advance correction
Compare the number of rotations immediately after, and if the difference is equal to or less than a predetermined value,
By ending the ignition timing advance correction, the specified ignition
And an arithmetic processing unit that searches for a time period.
Timing control device for an internal combustion engine . 2. The ignition timing control device for an internal combustion engine according to claim 1, wherein the coefficient is a coefficient approximating a change characteristic of a rotation speed with respect to an ignition timing.