JP2712538B2 - Engine ignition timing control device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an ignition timing control device that controls the ignition timing of an engine by electronic control.

[Conventional technology]

As is well known, in an accelerating state of the engine, a change in the rotation speed is large. Therefore, in order to optimally control the ignition timing, it is necessary to perform acceleration correction when estimating the rotation speed of the engine. Conventionally, an apparatus for performing acceleration correction using two ignition one cycle times has been proposed (for example,
JP-B-51-45002 and JP-B-61-37457).

[Problems to be solved by the invention]

However, in the above-described ignition timing control device, at least two or more ignition one cycle times are required to perform acceleration correction in an accelerated state of the engine.

Therefore, it takes time to perform the acceleration correction. Therefore, there is a problem that the accuracy of the rotation speed estimation is reduced due to the delay of the acceleration correction when the vehicle enters the acceleration state, and the accuracy of the ignition timing control is deteriorated.

Therefore, the present invention has been made to solve the above-described problems, and an object of the present invention is to make it possible to perform acceleration correction immediately after the engine is in an accelerated state, and to improve the engine acceleration state. It is an object of the present invention to improve the accuracy of ignition timing control by enabling the rotation speed to be estimated more accurately immediately after the start.

[Means for solving the problem]

In view of the above, according to the present invention, as shown in FIG. 1, in an acceleration state, one ignition cycle of the engine is detected by dividing the ignition cycle into a first rotation angle having a large change in rotation speed and a second rotation angle having a small change in rotation speed. Angle detection means 1 and first rotation angle time detection means 2 for detecting a time corresponding to the first rotation angle
Between the first rotation angle and the second rotation angle time, and the detected first rotation angle time and the second rotation angle time. The first estimating means 4 for performing acceleration correction based on the rotation angle of the first estimating means and estimating the next second rotational angle time, and the first estimating means 4
Setting means 5 for setting the timing of outputting the ignition signal in accordance with the next second rotation angle time estimated by the above, and output means 6 for outputting the ignition signal based on the timing set by the setting means 5 The gist of the present invention is an engine ignition timing control device including:

Further, the second rotation angle is an angle smaller than 1/2 of one ignition cycle before top dead center, and the first rotation angle is 1
It is preferable that the angle is obtained by subtracting the second rotation angle from the ignition cycle.

Further, the second rotation angle is approximately 1/3 of one ignition cycle before top dead center, and the second rotation angle is an angle obtained by subtracting the second rotation angle from one ignition cycle. This is preferable.

Further, a determination means for determining whether the engine is in a transient state based on the detected first rotation angle time and the second rotation angle time, and a required time of one ignition cycle are detected. The second for one ignition cycle angle
A second estimating means for estimating the next second rotation angle time based on the ratio of the rotation angles of the first and second rotation angles. The time is estimated, and when it is determined by the determination means that the state is a steady state, the second estimation
It is preferable to estimate the rotation angle time.

When the engine speed is equal to or less than the predetermined speed, the first estimating means 4 estimates the next second rotation angle time, and when the engine speed is higher than the predetermined speed, the second estimation It is preferable to estimate the next second rotation angle time by means.

[Action]

As a result, a signal that divides one ignition cycle into a first rotation angle having a large change in rotation speed and a second rotation angle having a small change in rotation speed is output from the rotation angle detection means 1 in an acceleration state of the engine. A first rotation angle time and a second rotation angle time corresponding to this signal are detected. Then, acceleration correction is performed by the first estimating means 4 to estimate the next second rotation angle time. The timing for outputting the ignition signal is set by the setting means 5 according to the estimated second rotation angle time of the next time, and the output means 6 outputs the ignition signal at the timing set by the setting means 5.

In addition, when the engine is determined to be in the transient state by the determining means, the first estimating means 4 is used. When the engine is determined to be in the steady state, the second estimating means is used.
The next second rotation angle time is estimated.

Alternatively, when the engine speed is equal to or lower than the predetermined speed, the first estimating means 4 estimates the next second rotation angle time by the second estimating means when the engine speed is higher than the predetermined speed. .

〔Example〕

Hereinafter, an embodiment in which the present invention is applied to a 4-cylinder 4-cycle engine will be described.

FIG. 2 shows a configuration diagram of the embodiment. Reference numeral 10 denotes a rotating shaft of a distributor 17 mounted on a four-cycle four-cylinder engine (hereinafter, referred to as an engine). Numeral 11 denotes a disk fixed to the rotating shaft 10 and rotating in synchronization with the rotation of the rotating shaft 10. On the circumference of the disk 11, a number corresponding to the number of cylinders (four in the embodiment)
Are provided at regular intervals. Reference numeral 12 denotes a rotation angle sensor (for example, an optical sensor or a hall sensor) that determines whether or not the slit 11a is present and outputs a pulse signal. 13
Denotes an electronic control unit (ECU), which includes a well-known central processing unit (CPU) 13a, a read-only memory (ROM) 13b, and a random access memory (RA).
M) It is configured as an arithmetic and logic operation circuit centered on 13c, backup RAM 13d, etc., and is interconnected via bus 13g with input port 13e for inputting from various sensors and port 13f for outputting control signals to various actuators. Have been.
Reference numeral 14 denotes an igniter that drives the power transistor 14a in response to an ignition signal output from the ECU 13. Reference numeral 15 denotes an ignition coil whose primary current is interrupted by the power transistor 14a. Reference numeral 16 denotes a distributor 17 on the secondary side of the ignition coil 15. It is a spark plug of each cylinder connected through the.

The electronic control unit 13 inputs an intake air amount, an intake air temperature, a cooling water temperature, a rotation angle, and the like via an input port 13e, calculates an ignition timing based on these, and converts the calculated ignition timing into time. After conversion, the control signal is output to the igniter 14 via the output port 13f.

Hereinafter, of the ignition timing control, the estimation of the rotation speed when the calculated ignition timing is converted into time will be described.

When the present inventors measured the change in the instantaneous rotation speed when the engine was in an accelerating state for various types of engines, the characteristics as shown in FIG. 3 were obtained. The characteristic diagram more apparent, after P _2, P ₄ speed increases initially from ignition, a characteristic comprised of ignition prior P _1, P ₃ immediately after ignition of P _2, P ₄ in a substantially constant rotational speed Characteristics were obtained.

Therefore, in FIG. 3, the second rotation angle with a small (substantially constant) rotation speed fluctuation in the previous ignition cylinder, that is, the second rotation angle,
The required rotation time Tθ _{A (i)} / θ _A per 1 CA between P _{1 and} P ₂ and the second rotation angle P ₃ -P ₄ in the current ignition cylinder
The difference between the time required for the rotation _{Tθ A (i + 1) /} θ A of per is caused by the rotational speed change caused between the first rotation angle or P ₂ -P ₃ large rotational speed fluctuation. Here, when the time required for the rotation between P ₂ -P ₃ and T.theta _{B (i),} the average value of the time required for the rotation per 1 ° CA during this period the _{Tθ B (i) / θ B} . here,
From FIG. 3 (a), it can be approximated that the rotation speed is increasing at a constant acceleration between P _{2 and} P _3, so that Tθ _{B (i)} / θ _B is P
A midpoint P between ₂ -P _1. Therefore, the following equation is established.

Transforming _{Tθ A (i) / θ A} -Tθ B (i) / θ B ≒ Tθ B (i) / θ B -Tθ A (i + 1) / θ A above formula Becomes

Therefore, the required rotation time Tθ _{A (i + 1)} between P _{3 and} P _4, that is, the rotation speed can be estimated. In the four-cylinder engine of the present embodiment, by setting θ _A = 60 ° CA and θ _B = 120 ° CA, it is possible to divide the rotation speed into a large region and a small region in the acceleration state.

Therefore, since the disk 11 makes one rotation for every two rotations of the engine, the slits 11a are each 30 degrees.

Therefore, when these θ _A and θ _B are substituted into the equation, T θ
_{A (i + 1)} = TθB _(i) −TθA _(i)

Also, by transforming the formula, Becomes here, Is a correction value in the acceleration state. This correction value can be used even in a deceleration state.

Similarly, Tθ _{B (i + 1)} can be estimated by the following equation.

As in the case of Tθ _{A (i + 1),} the above equation can be used in the deceleration state also in Tθ _{B (i + 1)} .

When this correction value is small, it can be determined that the vehicle is in a steady state. FIG. 4 shows the characteristics of the rotational speed in the steady state.
Therefore, this correction value corresponds to the rotational acceleration. Conventionally, when this correction value is small, that is, in a steady state, this correction value is set to 0 and Tθ _{A (i + 1)} = Tθ _{A ( i)} TθB _{(i + 1)} = TθA _(i) .

However, since the rotation fluctuation occurs, an error increases for a short time of Tθ _{A (i)} .

Therefore, in the present embodiment, in the steady state, TθA _(i) + TθB _{(i)
A (i + 1)} and Tθ _{B (i + 1)} are estimated. As a result, an error due to the rotation fluctuation difference can be corrected, and the estimation accuracy of TθA _{(i + 1)} and TθB _{(i + 1)} improves.

Therefore, in the steady state, Tθ is given by the following equation.
_{A (i + 1)} and Tθ _{B (i + 1)} are estimated.

_{Tθ A (i + 1) =} {Tθ A (i) + Tθ B (i)} × θ A / (θ A + θ B) Tθ B (i + 1) = {Tθ A (i) + Tθ B (i)} × θ _B / (θ _A + θ _B ) Next, the operation of the ignition timing control in the electronic control unit 13 will be described with reference to the flowchart of FIG.

This routine is an interrupt processing routine that is executed each time the input signal from the rotation speed sensor 12 rises or falls.

First, in step 100, it is determined whether the interrupt is due to the rising edge of the input signal or to the falling edge.
If it is determined in step 100 that the interruption is due to the fall, in step 101, TθB _(i) is measured and stored. This measurement of Tθ _{B (i)} is performed by subtracting the time at which the previous interrupt occurred from the time at which the current interrupt occurred, since the time at which the interrupt occurred is stored in a predetermined register.

Next, at step 102, it is determined whether the engine is in a transient state or a steady state. As this determination method, for example, Alternatively, | TθA _(i) −TθA _(i) |> k, where k is a constant. When this inequality holds, it can be determined that the state is a transient state.

If it is determined in step 102 that the state is a transient state, step 103
Is already determined stored in Tθ _{A (i),} using the _{Tθ B (i), Tθ B} (i + 1) = 4 × Tθ A (i) -Tθ B (i) by T.theta _{B (i +1)} can be estimated. Also, in the same manner as when it is determined in the steady state in step 102, As a result, Tθ _{B (i + 1)} can be estimated.

Next, in Step 105, Step 103 or Step 10
The timing T _{ON at} which the igniter control signal is turned _ON is set based on Tθ _{B (i + 1)} measured in step 4. As a setting method, assuming that the ignition signal is output from the top dead center P ₂ , P _{4 at} a rotation angle of θ _ig゜ CA before and a predetermined igniter control time T _DWL (for example, 5 msec), Is set by

If it is determined in step 100 that the interruption is due to rising, Tθ _{B (i)} is measured and stored in step 106. The measuring method at this time is the same as the measuring method in step 101.

In the following step 107, it is determined whether the engine is in a transient state or a steady state. The determination method is the same as the determination method in step 102. If it is determined in step 107 that the current state is the transient state, then in step 108, as in steps 103 and 104, TθA _{(i + 1)} = TθB _(i) −TθA _(i) . _{A (i + 1)} can be estimated. If it is determined in Step 107 that the vehicle is in the steady state, Step 109
In the same manner as Step 103, Step 104, and Step 108 Thus, Tθ _{A (i + 1)} can be estimated.

In the following step 110, the igniter control signal is turned ON or OFF.
Or to detect. Here, the igniter control signal is OFF, that is, in the rise time of the input signal from the rotation sensor 12, when still igniter control signal, as shown in dashed line in FIG. 3 (d) is not ON, T _ON at step 111 To reset. Reset is performed by the following equation.

Next, at step 112, T _OFF is set. This setting is performed by the following equation.

Finally, _TON or _TOFF set in steps 105, 111, and 112 is set in the timer.

Therefore, in the present embodiment, the rotation speed, that is, Tθ _{A (i + 1)}
Is estimated using pulse width times Tθ _A and Tθ _B that can be measured in one cycle of ignition in the previous cylinder. Therefore, since the transient correction can be performed from the ignition immediately after the transition, the ignition timing can be performed with higher accuracy than immediately after the transition. In addition, since the correction is performed even in the steady state, Tθ _{A (i + 1)} can be estimated with high accuracy, and the accuracy of the ignition timing control is improved even in the steady state.

Further, Tθ _{A (i + 1)} in a transient state, Tθ _{B (i + 1)} is _{Tθ A (i + 1) =} Tθ B (i) -Tθ A (i) Tθ B (i + 1) = 4 × Tθ _{A (i)} −Tθ _{B (i) In the} steady state, Tθ _{A (i + 1)} and Tθ _{B (i + 1)} are And the software processing load on the electronic control unit 13 can be reduced.

Further, in this embodiment, as the rotation angle detecting means, the rotation angle sensor is used as the detection object and the detection object provided with the slit 11a in the disk 11, but as another embodiment, the protrusion is provided on the dielectric disk. The detected object and the detection object may be a rotation angle detecting means using an electromagnetic pickup, and P ₁ and P ₂ may be detected by separate sensors.

Further, in the present embodiment, in a steady state, the ratio of θ _A , θ _{B to} the time required for one cycle of ignition
_{A (i + 1)} and Tθ _{B (i + 1)} has been estimated, Tθ _{A (i + 1)} as in the prior art _{= Tθ A (i) Tθ B} (i + 1) = Tθ B _It may be estimated by _(i) .

In this embodiment, as shown in FIG.
Alternatively, the transient state is determined in step 107, and the estimation means is switched. However, the deterioration of the ignition timing accuracy in the transient state becomes remarkable when the engine speed is low at a large change in the number of revolutions in one ignition cycle. Therefore, as shown in step 102 or step 107 in FIG.
The estimating means may be switched depending on whether or not is less than or equal to a predetermined rotation speed.

And even in engines other than four-cylinder engines,
The ratio of θ _A , θ _B to the rotation angle of the ignition cycle is 1: 2
It is good to set to. However, if the number of cylinders increases and θ _A becomes smaller than the maximum advance angle, it becomes impossible to realize this. Therefore, in order to secure the maximum advance angle, for example, in a six-cylinder engine, the ratio between θ _A and θ _B is 1: 1. Divided into This allows
Although the accuracy is lower than when the ratio between θ _A and θ _B is divided into 1: 2, the accuracy is improved to some extent.

[Effects of the Invention] As described in detail above, in the ignition timing control device according to the present invention, the correction in the estimation of the rotational speed in the accelerated state can be corrected by the first rotational angle time and the first rotational angle time that can be measured in one ignition cycle in the previous cylinder. Since the correction is performed based on the rotation angle time of 2, the rotation speed can be corrected immediately after the acceleration state, so that the excellent effect that the accuracy of the ignition timing control in the acceleration state can be improved. is there.

[Brief description of the drawings]

FIG. 1 is a diagram corresponding to claims of the present invention, and FIG.
FIG. 3 is a configuration diagram showing one embodiment applied to a four-cylinder cylinder engine, FIG. 3 is a timing chart of the above embodiment in an accelerated state, FIG. 4 is a timing chart of a steady state of the above embodiment, and FIG. FIG. 6 is a flowchart for explaining the operation of another embodiment. 1 ... rotation angle detecting means, 2 ... first rotation angle time detecting means, 3 ... second rotation angle time detecting means, 4 ... first estimating means, 5 ... setting means, 6 ... Output means.

Claims (5)

(57) [Claims] A rotation angle detection means for detecting one ignition cycle of the engine in an acceleration state by dividing the ignition cycle into a first rotation angle having a large change in rotation speed and a second rotation angle having a small change in rotation speed; First rotation angle time detection means for detecting a time corresponding to one rotation angle; second rotation angle time detection means for detecting a time corresponding to the second rotation angle; and the first rotation angle During the period, the engine approximates to perform an equal acceleration motion, and the acceleration correction is performed based on the detected first rotation angle time and the second rotation angle time and the detected first rotation angle and the second rotation angle. A first estimating means for estimating a next second rotation angle time, and a timing for outputting an ignition signal according to the next second rotation angle time estimated by the first estimating means. Setting means, and a tag set by the setting means. Engine ignition timing control device according to an outputting means for outputting the ignition signal based on the timing. 2. The second rotation angle is smaller than 1/2 of one ignition cycle before top dead center, and the first rotation angle is obtained by subtracting the second rotation angle from one ignition cycle. The ignition timing control device for an engine according to claim 1, wherein the angle is set to a predetermined angle. 3. The second rotation angle is approximately 1/3 of one ignition cycle before top dead center, and the second rotation angle is obtained by subtracting the second rotation angle from one ignition cycle. 3. The engine ignition timing control device according to claim 2, wherein the angle is an angle. 4. A determining means for determining whether the engine is in a transient state based on the detected first rotation angle time and the second rotation angle time, and detecting a time required for one ignition cycle. A second estimating means for estimating a next second rotational angle time based on a ratio of the second rotational angle to one ignition cycle angle based on the required time, and a transient state is determined by the determining means. If the first
Estimating the next second rotation angle time by the estimating means, and estimating the next second rotation angle time by the second estimating means when the determination means determines that the vehicle is in the steady state. The ignition timing control device for an engine according to claim 1, wherein: 5. When the engine speed is equal to or lower than a predetermined speed, the first estimating means estimates the next second rotation angle time. When the engine speed is higher than a predetermined value, the second estimating means estimates the second rotation angle time. 2. The engine ignition timing control device according to claim 1, wherein the second rotation angle time is estimated by the estimating means.