JP2532652Y2 - Ignition / energization control device for internal combustion engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an ignition / energization control device for an internal combustion engine.

<Prior Art> Conventionally, as an ignition control device for an internal combustion engine, there is an ignition control device in which ignition timing and energization control by an ignition coil are performed by an angle calculation value in synchronization with the crank angle of the engine (see FIG. 7).

<Problem to be Solved by the Invention> By the way, the energization time (DWL) is originally a charging time of the ignition energy (back-electromotive energy) to the ignition coil.
It is obtained from the current i (t) flowing through the ignition coil 14 shown in the figure (back electromotive energy = 1 / 2Li ² , L: inductance of the coil). Thus, the current i (t) flowing through the ignition coil 14 is obtained. Since the back electromotive energy does not increase even if the ignition coil 14 is kept energized after) is saturated, * shown in FIG.
Is preferably set as the target value of the energization time (DWL).
Since the target value of the energization time (DWL) is a time constant time determined by the applied voltage VB of the ignition coil 14, the energization control is performed by converting this time into an engine rotation angle.

By setting the non-energization time (angle) as ▲ ▼, the above DWL can be obtained as a result (▲ ▼ = 1
80-DWL) (see FIG. 7).

Therefore, in such a time control structure, the above-described conversion is troublesome, and the processing routine becomes complicated.
As a result, the accuracy of the energization time is deteriorated.

Therefore, the present invention has been made in view of the above-mentioned conventional problems,
An object of the present invention is to simplify a processing routine and improve control accuracy of the energizing time by a configuration in which ignition timing and energization control by an ignition coil are performed by a combined control of time and angle.

<Means for Solving the Problems> For this reason, the ignition / energization control device for an internal combustion engine according to the present invention outputs a reference pulse signal at a predetermined crank angle position and a unit angle of a crank shaft as shown in FIG. Crank angle detecting means for outputting a unit pulse signal every time, ignition timing setting means for setting an ignition timing according to engine operating conditions, and generation of an easy pulse signal from the time when the reference pulse signal is generated from the crank angle detecting means An ignition control unit that counts the number and outputs an ignition signal when the count value matches the ignition timing set by the ignition timing setting unit; and a unit that calculates a target value of the energization time to the ignition coil from the battery voltage. Means for setting the non-energization time by subtracting the energization time target value from the previous ignition cycle; energization timer means for counting the set non-energization time simultaneously with ignition; Means for starting energization of the ignition coil based on the energization start signal at the time when the value matches the predetermined value.

<Operation> In this configuration, the crank angle from the reference pulse signal by the crank angle detecting means to the ignition timing by the ignition timing setting means is set, and the number of output unit pulse signals corresponding to the set crank angle is finished counting. When,
An ignition signal is output.

Since the target value of the energization time to the ignition coil is a time constant time determined by the voltage applied to the ignition coil, the ignition time is calculated by subtracting a predetermined time determined by the battery voltage from the ignition cycle from the ignition timing by the ignition control means. Start energizing the coil.

<Example> Hereinafter, an example of the present invention will be described with reference to the drawings.

In FIG. 2, air is sucked into the engine 1 via an air cleaner 2, an intake duct 3, a throttle valve 4, and an intake manifold 5. The intake manifold 5 is provided with an electromagnetic fuel injection valve 6 for each cylinder and injects fuel supplied from a fuel pump (not shown) and controlled to a predetermined pressure by a pressure regulator to the engine 1.

The control of the fuel injection amount is calculated by a microcomputer built in the control unit 7 based on the intake air flow rate Q detected by the air flow meter 8 and the cycle T _REF of the reference pulse signal REF from the crank angle sensor 9. From the engine speed N, the basic fuel injection amount Tp is calculated, and this is corrected appropriately to determine the final fuel injection amount Ti,
Based on a reference pulse signal REF from the crank angle sensor 9, a drive pulse signal having a pulse width corresponding to the Ti is injected at a predetermined timing synchronized with the engine rotation.
Output to

The square cylinders of the engine 1 are provided with spark plugs 10, to which high voltages generated by an ignition coil 11 are sequentially applied via a distributor 12, thereby igniting fireworks and causing the mixture to burn. . Here, the ignition coil 11 controls a high-voltage generating engine via a power transistor 13 attached thereto. Therefore, the ignition timing is controlled by controlling the ON / OFF timing of the power transistor 13 by the ignition signal from the control unit 7.

The microcomputer in the control unit 7 calculates the ignition timing based on the cycle T _REF of the reference pulse signal REF from the crank angle sensor 9 by the ignition timing setting means shown in step 1 of the flowchart of FIG. Based on the engine speed N and the basic fuel injection amount Tp calculated as described above to represent the engine load, the ignition timing (ignition advance angle; The angle is memorized.) Search ADV. This routine is executed as a background job.

Then, the ignition control is executed in synchronization with the reference pulse signal REF from the crank angle sensor 9 in order to output an ignition signal at the ignition timing ADV set in this way and perform ignition.

This ignition control counts the number of generations of the unit pulse signal POS from the generation of the reference pulse signal REF based on the detection signal from the crank angle sensor 9 and, when the count value matches the set data, the ignition signal Is output.

On the other hand, means for calculating the target value of the energizing time to the ignition coil 11 from the battery voltage, means for setting the non-energizing time by subtracting the target value of the energizing time from the previous ignition cycle, and setting the non-energizing time to ignition Power supply control means including power supply timer 17 in FIG. 3 as power supply timer means for counting simultaneously, and means for starting power supply to ignition coil 11 based on a power supply start signal when the timer value matches a predetermined value is provided. The energization time target value calculating means, the non-energization time setting means, and the energization start means are provided in a microcomputer in the control unit 7 as software.

Next, such ignition control and energization control will be described based on the block diagram of FIG. 3, the flowchart of FIG. 4, and the time chart of FIG.

In the flowchart of FIG.
In FIG. 1, the period T _REF of the reference pulse signal REF from the crank angle sensor 9 is described above.
Engine speed N calculated based on
The ignition timing ADV is read from Tp with reference to a map.

In S2, the crank angle ADV _REF from the reference pulse signal REF to the ignition timing ADV is set by subtracting the ignition timing ADV from CRSET. That is, the reference pulse signal RE
F is output at the angle CRSET before top dead center,
On the other hand, since the ignition timing ADV data stored in the map indicates the number of times before the top dead center, the CRSET-AD
V is the crank angle AD from the reference pulse signal REF to the ignition timing
V _REF (see FIG. 6).

Further, in S2, the crank angle AD set as described above is set.
The number of outputs of the unit pulse signal POS corresponding to V _REF is counted down by the ignition counter 15 shown in FIG. 3, and when this count value becomes 0 and an underflow (UDF) occurs, the F / F
An ignition signal is output to the power transistor 13 via 16, and spark ignition is performed by the spark plug 10.

In S3, since the target value of the energization time (DWL) to the ignition coil 11 is a time constant time determined by the voltage VB applied to the ignition coil 11, the target value of the LWL is retrieved from the table as a function of VB.

Then, in the next S4, the non-energization time ▼ is set by subtracting this DWL from the previous ignition cycle.

In S5, the de-energization time set as described above ▲
At the same time as the ignition of ▼, the energization timer 17 shown in FIG. 3 counts down, the timer value becomes 0, and the underflow (UD
At the point of occurrence of F), an energization start signal is output to the power transistor 13 via the F / F 16 and an energization current flows through the ignition coil 11.

The ignition control means according to the present invention comprises software means for S1 and S2 in the above flowchart and hardware means such as the ignition counter 15, F / F 16 and power transistor 13 in FIG.

Further, the energization control means according to the present invention is a software means of S3, S4 and S5 of the above flow chart, namely, the energization time target value calculation means of S3, the non-energization time setting means of S4 and the energization start means of S5, It is composed of hardware means such as the energization timer 17, F / F16 and power transistor 13 shown in FIG.

As is apparent from the above description, the ignition timing is determined based on the detection signal from the crank angle sensor 9 based on the reference pulse signal.
Determined by counting the number of occurrences of the unit pulse signal POS since the occurrence of REF, the energizing engine energizes the ignition coil 11 when measuring a time obtained by subtracting a predetermined time determined by the battery voltage from the ignition cycle from the ignition timing. Because it is determined by starting, that is, since the ignition / energization control is executed by the combined control of time and angle, it takes time to convert as in the case where the ignition / energization control is executed only with the conventional angle calculation value. , The processing routine can be simplified, and the accuracy of the energization time can be improved.

<Effects of the Invention> As described above, according to the ignition / energization control device of the internal combustion engine of the present invention, the ignition timing is determined by counting the number of generations of the unit pulse signal from the generation of the reference pulse signal, The energization period is determined by starting energization of the ignition coil when a time obtained by subtracting a predetermined time determined by the battery voltage from the ignition cycle is measured from the ignition timing, so that the processing routine is simplified and the energization time is reduced. This is a practical effect that can improve the accuracy.

[Brief description of the drawings]

FIG. 1 is a diagram corresponding to claims of the present invention, FIG. 2 is a system diagram showing an embodiment of the present invention, FIG. 3 is a flowchart for explaining the operation of the embodiment, and FIG. 4 is a block diagram of the embodiment. FIGS. 5, 5 and 6 are time charts for explaining the operation of the above-described embodiment, respectively, FIG. 7 is a time chart for explaining the operation of the conventional example, and FIG. FIG. 9 is a characteristic diagram of a current supplied to an ignition coil in the conventional example. 7 ... Control unit, 8 ... Air flow meter, 9 ... Crank angle sensor, 10 ... Spark plug, 11 ... Ignition coil, 13 ... Power transistor, 15 ... Ignition counter, 17 ... Electrification timer

Claims (1)

(57) [Scope of request for utility model registration] Crank angle detection means for outputting a reference pulse signal at a predetermined crank angle position and outputting a unit pulse signal for each unit angle of a crankshaft, and an ignition timing setting for setting an ignition timing according to engine operating conditions. Means for counting the number of unit pulse signals generated since the generation of the reference pulse signal from the crank angle detecting means, and outputting an ignition signal when the count value matches the ignition timing set by the ignition timing setting means. Means for calculating an energization time target value for the ignition coil from the battery voltage; means for setting the energization time by subtracting the energization time target value from the previous ignition cycle; Energizing timer means for counting simultaneously with ignition, and means for starting energizing the ignition coil based on the energizing start signal when the timer value matches a predetermined value. Ignition and current control apparatus for an internal combustion engine, characterized by being configured and a non-energization control means.