JPH0715278B2 - Ignition timing control device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a device for controlling the ignition timing of an internal combustion engine based on a reference position detection signal corresponding to each cylinder, and particularly to an abnormal retardation of the ignition timing braking process timing. The present invention relates to an ignition timing control device that can prevent corners.

[Prior Art] A conventional electronic ignition timing control device, for example, as shown in FIG. 5, responds to a crank angle based on a reference position detection signal which is inverted at predetermined first and second reference positions. The ignition timing is calculated, the ignition time and the energization start time are determined based on the time from the first and second reference positions, and the ignition timing and the energization time are controlled.

In this case, the first reference position is BTDC 75 ° (from top dead center TDC 7
(Crank angle before 5 °), 2nd reference position is BTDC 5 °
(Crank angle 5 ° before the top dead center TDC).
Further, the specific cylinder is identified by using a cylinder identification signal (not shown) having a phase different from that of the pulse signal shown in FIG.

In such an ignition timing control device, since the ignition time is controlled by the timer time, as shown in FIG.
The target ignition timing is on the advance side of the second reference position (for example,
(BTDC is about 8 °), if the reference position detection signal pulse suddenly advances at the initial stage of rapid acceleration of the engine, the target ignition timing cannot be tracked and the ignition timing is retarded abnormally from the second reference position. Due to this abnormal ignition retardation, abnormal vibration called power loss or knocking occurs. Therefore, in order to prevent this, a so-called ignition timing braking process for forcibly cutting off the ignition coil current at the time of detecting the second reference position has been conventionally performed. Has been done.

On the other hand, for the purpose of identifying the cylinder only by the reference position detection signal, as shown in FIG. 7, the second reference position of only the specific cylinder is retarded to a predetermined crank angle (for example, about 10 °).
When using the reference position detection signal offset by only
The second reference position for only a specific cylinder is ATDC 5 °. In this case, the cylinder identification signal is unnecessary, and the specific cylinder is identified by the difference in the cycle ratio of each pulse of the reference position detection signal.

However, if the ignition timing pawl processing as described above is performed using the second reference position in FIG. 7, a time shift corresponding to a predetermined offset angle occurs for the specific cylinder, so the ignition timing pawl processing timing is abnormal. It retards and causes power loss and knocking as described above.

[Problems to be Solved by the Invention] In the conventional ignition timing control device as described above, the reference position detection signal obtained by offsetting the second reference position of the specific cylinder to the retard side as shown in FIG. 7 is used. In this case, there is a problem that a time shift (abnormal retardation) corresponding to the predetermined offset angle occurs during the ignition timing pawl processing of the specific cylinder, which causes power loss and knocking.

The present invention has been made to solve the above problems, and when a reference position detection signal obtained by offsetting the second reference position of a specific cylinder to the retard side by a predetermined angle is used, at the initial stage of rapid acceleration of the engine. It is an object of the present invention to obtain an ignition timing control device capable of preventing an abnormal retardation of the ignition timing pawl processing timing.

[Means for Solving the Problems] In the ignition timing control device according to the present invention, the specific cylinder is identified by offsetting the second reference position of the reference position detection signal of the specific cylinder to the retard side by a predetermined crank angle. The specific cylinder identification means to perform, and for each cylinder, the target ignition timing is set on the advance side of the crank angle of the engine corresponding to the second reference position other than the specific cylinder, and the second reference position Ignition timing pawl processing means for performing ignition immediately when ignition has not yet been made at the time of detection, and offset correction processing means for substantially advancing the ignition timing pawl processing by a predetermined crank angle. is there.

[Operation] According to the present invention, the ignition timing braking process is performed without performing the offset correction process before the cylinder identification is determined, and the offset timing correction process is performed on the specific cylinder after the cylinder identification is determined and then the ignition timing braking is performed. Perform processing.

[Embodiment] FIG. 1 is a block diagram schematically showing an ignition timing control device according to an embodiment of the present invention.

In the figure, (1) is a rotation signal generator that generates a rotation signal corresponding to the reference position detection signal of FIG. 7, and is, for example, the first and second rotation signals for each cylinder that rotate in synchronization with the crankshaft.
It is composed of a disk having arcuate slits corresponding to the reference position (crank angle) and optical sensors arranged facing these slits. (2) is an interface circuit connected to the rotation signal generator (1).

Reference numeral (3) is a microcomputer for taking in a rotation signal via the interface circuit (2), and a specific cylinder identifying means (4) for identifying a specific cylinder based on a cycle ratio of a reference position detection signal and a second cylinder for the specific cylinder. Offset correction processing means (5) for substantially advancing the ignition timing pawl processing by a predetermined crank angle which is retarded from the reference position, and a crank angle at which the target ignition timing corresponds to the second reference position. An ignition timing pawl processing means (6) for performing an ignition timing pawl processing when the second reference position is detected when set to a more advanced side, and a timer based on the time from the first or second reference position. It includes an ignition time and energization start time calculating means (7) for calculating the ignition time and energization start time by control.

FIG. 2 is a flow chart showing the operation sequence of the present invention.

FIG. 3 is an explanatory view showing the target ignition timing range to which the ignition timing stopping process is applied in association with the reference position detection signal waveform, and (a) is the target ignition timing range after the cylinder identification is confirmed,
(B) shows the target ignition timing range before the cylinder identification is confirmed, and A ₀
Is the target ignition timing range without offset correction processing,
A ₁ is the target ignition timing range when the offset correction processing is performed.

FIG. 4 is a waveform diagram showing a reference position detection signal and an ignition coil current according to the present invention, (a) is a reference position detection signal waveform, and (b) is a cylinder identification confirmation when the target ignition timing is fixed to BTDC 10 °. The previous ignition coil current waveform, (c) is the ignition coil current waveform after the cylinder identification is confirmed when the target ignition timing is fixed to TDC.

Hereinafter, the operation of the ignition timing control device shown in FIG. 1 will be described with reference to FIGS. 2 to 4.

First, the specific cylinder identifying means (4) identifies the specific cylinder based on the cycle ratio of each pulse of the reference position detection signal.
At this time, in a transitional state such as the initial start-up, the pulse cycle is not steady and cylinder identification may be difficult. Therefore, it is determined whether or not the cylinder identification is confirmed (step S1). , It is determined whether the cylinder to be controlled is a specific cylinder (step S2).

If it is determined in step S2 that the cylinder is a specific cylinder,
The offset correction processing means (5) pawls by a predetermined crank angle (for example, 10 °) corresponding to the offset retard in order to prevent the ignition abnormal retard due to the offset retard of the second reference position of the specific cylinder. Offset correction processing is performed so that the processing advances (step S3). That is, as shown in FIG. 3 (a), the target ignition timing range to which the ignition timing braking process is applied is extended only by the specific cylinder by the predetermined crank angle, and the process proceeds to step S4.

If it is determined in step S2 that the cylinder is the other cylinder, it is not necessary to perform the offset correction process on the other cylinder, and thus step S3 is bypassed and the process proceeds to step S4.

Therefore, the ignition timing stop processing means (6) has the currently set target ignition timing within the range A ₀ for other cylinders and within the range A ₁ for the specific cylinder. In this case, the ignition timing braking process described above is performed (step S4).
I do.

Here, in step S3, the target ignition timing range to be stopped is expanded and the offset correction processing is performed. Since the ignition timing stop processing is performed by the second reference position of the reference position detection signal, the ignition timing is set in step S4. This is because the timing itself of the pawl processing cannot be directly advanced.

For example, the target ignition timing range for applying pawl is normally set to the first ignition timing range.
The range A ₀ from the reference position (BTDC75 °) of the other cylinder to the second reference position (BTDC5 °) of another cylinder is A ₀ , but during the offset correction process, the second reference position (ATDC15 °) up to the range A ₁ . Therefore, when the target ignition timing is fixed at the top dead center TDC (BTDC0 °) as shown in FIG. 4 (c), when the target ignition timing becomes the retard side from the second reference position due to the initial stage of rapid acceleration, Although the ignition timing stop processing is not performed for the other cylinders, the target ignition timing is within the range A ₁ for the specific cylinder, so the ignition timing stop processing is performed at the second reference position (ATDC 5 °). The ignition timing is prevented from being abnormally retarded.

On the other hand, in step S1, when it is determined that the cylinder identification is not yet confirmed, the cylinder determination step S2 and the offset correction processing step S3 are bypassed, and the ignition timing stop processing step S4 is performed to perform offset correction for all cylinders. The ignition timing stopping process is performed without performing the process. That is, the target ignition timing range to which the ignition timing braking is applied is the range regardless of other cylinders or specific cylinders, as shown in FIG. 3 (b).
It remains A ₁ . Therefore, when the target ignition timing is about BTDC10 ° as shown in FIG. 4 (b), if the target ignition timing is retarded from the second reference position (ATDC5 °) of the specific cylinder in the initial stage of rapid acceleration, the normal operation is performed. , The ignition timing stopping process is performed at the second reference position ATDC 5 °.

As described above, the normal ignition timing stopping process (step S4) is performed without performing the offset correction process before the cylinder identification is determined, and the offset correction process is performed only for the specific cylinder after the cylinder identification is determined. After performing (step S3), ignition timing stop processing (step S4) is performed.

[Effects of the Invention] As described above, the present invention provides a specific cylinder identifying means for identifying a specific cylinder by offsetting the second reference position of the reference position detection signal for the specific cylinder to the retard side by a predetermined crank angle. , The target ignition timing is set for each cylinder on the advance side of the crank angle of the engine corresponding to the second reference position other than the specific cylinder, and the ignition is still performed at the time when the second reference position is detected. If the cylinder identification is not established, the ignition timing pawl processing means for immediately performing ignition and the offset correction processing means for substantially advancing the ignition timing pawl processing by a predetermined crank angle are provided. Ignition timing locking processing is performed without performing processing, and after the cylinder identification is confirmed, offset correction processing is performed only for specific cylinders, and ignition timing locking processing is then performed. There is an effect that it is possible to obtain an ignition timing control device capable of preventing an abnormal ignition retard in the ignition timing braking process during engine transient such as the initial stage of rapid acceleration.

[Brief description of drawings]

FIG. 1 is a block diagram showing an outline of an ignition timing control device according to an embodiment of the present invention, FIG. 2 is a flow chart diagram showing an operation sequence of the present invention, and FIG. 3 is a target ignition to which an ignition timing stopping process is applied. FIG. 4 is an explanatory view showing the time range corresponding to the reference position detection signal waveform, FIG. 4 is a waveform diagram showing the reference position detection signal and the ignition coil current according to the present invention, and FIG. 5 is a waveform diagram showing the conventional reference position detection signal. FIG. 6 is a waveform diagram of a reference position detection signal and an ignition coil current of a device having a conventional ignition timing stopping function, and FIG. 7 is a reference when a second reference position is offset by a predetermined crank angle only in a specific cylinder. It is a wave form diagram which shows a position detection signal. (1) ... Rotation signal generator (4) ... Specific cylinder identification means (5) ... Offset correction processing means (6) ... Ignition timing pawl processing means (7) ... Ignition time and energization start time calculation means BTDC75 ° ... First reference position BTDC5 °, ATDC5 ° ... second reference position a ₀ ... offset correction ignition timing pawl treatment before the target ignition timing ignition timing pawl process is applied range a ₁ ... after the offset correction process is applied Target ignition timing range S1 ... Step for determining whether cylinder identification is confirmed S2 ... Step for determining a specific cylinder S3 ... Step for performing offset correction processing S4 ... Step for performing ignition timing stopping processing Note that the same reference numerals in the drawings are the same or corresponding parts. Indicates.

Claims (1)

[Claims] 1. An ignition timing is calculated on the basis of a reference position detection signal indicating predetermined first and second reference positions corresponding to each cylinder in synchronism with the rotation of an engine, and the first or second reference position is calculated. In an ignition timing control device that controls the ignition timing according to the time from the position, the specific cylinder is identified by offsetting the second reference position of the reference position detection signal to the retard side by a predetermined crank angle only in the specific cylinder. Specific cylinder identification means, and for each cylinder, a target ignition timing is set on an advance side of a crank angle of the engine corresponding to a second reference position other than the specific cylinder, and the second reference position Ignition timing pawl processing means for igniting immediately when the ignition timing pawl processing is not yet ignited, and offset compensation for substantially advancing the ignition timing pawl processing by the predetermined crank angle. Processing means, the ignition timing stopping process is performed without performing the offset correction process before the identification of the cylinder is determined, and the offset correction process is performed on the specific cylinder after the identification of the cylinder is determined. The ignition timing control device is characterized in that the ignition timing stopping process is carried out.