JPH02223679A - Ignition timing control device for internal combustion engine - Google Patents

Abstract

PURPOSE:To prevent the generation of the heat of a power transistor and an ignition coil by a method wherein when it is decided by a motion mode discriminating means that an engine is started or a battery voltage exceeds a given value, an ignition timing is controlled by means of a second ignition mode means. CONSTITUTION:When it is decided by a motion mode discriminating means 8 that an engine is in a starting mode, reduction of a time of energization applied on an ignition coil 6 is calculated, and based on the calculating result, ignition is controlled by means of a second ignition mode 10. The waveform of a current energized to the coil 6 is such that a conventional pulse waveform shown by a broke line is reduced to a pulse waveform shown by a solid line, and the thermal loads of a power transistor 5 and the coil 6 are widely reduced. When it is discriminated that an engine is in a usual mode, usual ignition timing computation is effected, and ignition is effected by a first ignition mode means 9. When it is detected that a battery voltage exceeds a given value, the energizing time of the coil 6 is calculated to reduction, and an ignition timing is controlled by means of the ignition mode 10.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to an improvement in an ignition timing control device for, for example, a multi-cylinder internal combustion engine.

[Prior Art] FIG. 5 is a diagram showing a schematic configuration of a conventional ignition timing control device for a six-cylinder internal combustion engine.

(1) is a signal (f &
(2) is a rotational signal generator that generates the signal shown in FIG. (
2) and the microcomputer (4), (5) is a power transistor that is turned on and off according to a control signal from the microcomputer (4), and (6) is a power transistor (5). ) that generates a high voltage on its secondary side when it is turned off.

(7) is a spark plug that ignites the high voltage generated by this ignition coil (6).

FIG. 6 is a diagram showing operating waveforms of each part in FIG. 5. In the figure, B75° and B5° are respectively 75° before top dead center.
, 5 degrees before top dead center.

A conventional ignition timing control device for an internal combustion engine is configured as described above, and a signal synchronized with the rotation of the engine is used to control the ignition timing between internal combustion engines.

This signal as shown in FIG. 6(a) is normally output from a rotation signal generator (1) attached to the camshaft or crankshaft of one engine. This output signal is input to the microcomputer (4) via the interface circuit (3) together with various sensor signals from various sensors (2) that detect the operating states of other engines. An ignition timing control output signal calculated by a microcomputer (4) based on these sensor information controls an ignition coil (6) via a power transistor (5). 9 In the cranking state at the time of starting the engine, as shown in Fig. 6, the output signal of the engine rotation signal generator (1) (Fig. 6 (a)
) controls the energization/cutoff of the ignition coil (6). As a result, a current as shown in FIG. 6(b) flows through the negative side of the ignition coil (6).

[Problems to be Solved by the Invention] In the conventional ignition timing control device for an internal combustion engine as described above,
Bypass ignition control at startup means that as the number of cylinders increases, the number of times the ignition coil is energized and the amount of time it takes to energize increases, and in the worst case, the ignition coil is constantly energized.

This increases the thermal load on the power transistor that controls the ignition coil, and in the worst case, causes thermal damage such as burnout, which can lead to dielectric breakdown at the joints of the power transistor.

This invention was made to solve this problem, and the ignition timing of an internal combustion engine is reduced in one energization time at startup or when the battery voltage is higher than a predetermined voltage, thereby suppressing heat generation in the power transistor and ignition coil. The purpose is to obtain a control device.

[Means for Solving the Problems] The ignition timing control device for an internal combustion engine according to the present invention has nine rotations that generate signals indicating first and second predetermined reference positions corresponding to each cylinder in synchronization with the rotation of the engine. In an ignition timing control device that controls engine ignition based on the output signal of a signal generator and the output signals of various sensors that detect the operating state of the engine, operation mode discrimination is used to determine whether one engine is in normal operation or in startup mode. (1) first ignition mode means for performing a first ignition mode using an ignition timing control signal calculated from the output signal of the rotation signal generator and the output signal of the sensor signal during normal operation; and reducing the energization time of the ignition coil. and second ignition mode means for performing the second ignition mode in response to a control signal.

[Operation] In the present invention, only when the operation mode determining means determines that the engine is starting, and the sensor detects that the battery voltage is equal to or higher than a predetermined voltage, the second ignition mode means adjusts the ignition timing. Be in control.

[Embodiment] FIG. 1 is a block diagram showing an ignition timing control device for an internal combustion engine according to an embodiment of the present invention.
-(3), (5)-(7) are the same as the conventional ones.

Microcomputer (4A).

Operation mode determining means (8), first ignition mode means (
9) and second ignition mode means (10).

FIG. 2 is a diagram showing operating waveforms of each part in FIG. 1.

FIG. 3 shows a diagram illustrating the calculation for reducing the energization time according to the present invention.

FIG. 4 is a diagram showing an operation flowchart of the present invention.

In the ignition timing control device for an internal combustion engine configured as described above, the operation mode determining means (8)
If it is determined that the starting mode is in step S3, the energization time applied to the ignition coil (7) is reduced.
Then, carry out as shown in Fig. 3. In other words, the reduction time tc is calculated by finding the time 1゛ in the interval between 5゜ before top dead center (B5゜) and 75゜ before top dead center (50゛ crank angle interval). tc=
kT (here.

T=period between B5° and B75°, determined by = reduction coefficient). In this way, the reduction in the energization time of the ignition coil (6) is calculated. Based on this result, the second ignition mode means (10) performs ignition control, and the current waveform applied to the ignition coil (6) is shown in FIG.
As shown in a), the conventional pulse waveform shown by the broken line in Fig. 3 is reduced to the pulse waveform shown by the solid line, and the thermal The load is significantly reduced compared to the conventional method. Furthermore, if it is determined in step S1 that the engine is in the normal mode, the microcomputer (4A
) performs normal ignition timing calculations and ignites the engine using the first ignition mode means (9).

On the other hand, if the various sensors (2) detect that the battery voltage is equal to or higher than the predetermined voltage, the process proceeds to step S2).

In step S3, install the ignition coil (6) as described above.
The energization time of the second ignition mode means (10
) controls the ignition timing. Also.

If the battery voltage is below a predetermined voltage, the first ignition mode means (9) performs normal ignition timing calculation and ignition control in step S4.If the battery voltage is above a predetermined voltage, the ignition coil (6) is energized. Since the pulse can have a rapid rise, normal ignition operation can be performed even if the energization time is reduced, but if the battery voltage is below a predetermined voltage, a energization pulse with a rapid rise cannot be obtained.

If such reduction control is performed, normal ignition operation cannot be performed.

[Effects of the Invention] As explained above, the present invention provides an output signal of a rotation signal generator that generates a signal indicating the first and second predetermined reference positions corresponding to each cylinder in synchronization with the rotation of one engine, and the output signal of the engine. In an ignition timing control device that controls ignition of an engine based on output signals of various sensors that detect operating conditions, an operation mode discriminating means for determining whether one engine is in a normal state or in a starting state, and the rotation signal generator in a normal state. a first ignition mode means that performs a first ignition mode using an ignition timing control signal calculated from the output signal of the sensor signal and the output signal of the sensor signal; and a second ignition mode that performs a second ignition mode using a control signal for reducing the energization time of the ignition coil. Since it is equipped with a second ignition mode means, by reducing the energization time at the time of starting, it suppresses the heat generation of the ignition coil and power transistor, prevents burnout, and ensures the reliability of the ignition coil and power transistor. There is.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of an ignition timing control device for an internal combustion engine according to an embodiment of the present invention, FIG. 2 is an operation waveform diagram of each part of FIG. 1, and FIG. For explanation purposes, FIG. 4 is an operational flowchart of the present invention, FIG. 5 is a schematic diagram of a conventional ignition timing control device for an internal combustion engine, and FIG. 6 is an operational waveform diagram of each part of FIG. In the figure, (1)... rotation signal generator, (2)...
・Various sensors, (3)...interface. (4A)...Microcomputer, (5)...Power transistor, (6)...Ignition coil,
(7)...Spark plug, (8)...Operation mode determining means, (9)...First ignition mode means. (10)...Second ignition mode means. Note that the same reference numerals in each figure indicate the same or corresponding parts. Agent Teruji So Gado Teruji 3rd figure 4th figure procedural amendment March 26, 1990

Claims (1)

[Claims] The first and second cylinders correspond to each cylinder in synchronization with the rotation of the engine.
In an ignition timing control device that controls engine ignition based on the output signal of a rotation signal generator that generates a signal indicating a predetermined reference position of the engine and the output signals of various sensors that detect the operating state of the engine, the ignition timing control device determines whether the engine is in normal operation or not. an operation mode discriminating means for discriminating whether it is a starting time; and a first ignition unit that performs a first ignition mode using an ignition timing control signal calculated from the output signal of the rotation signal generator and the output signal of the sensor signal during normal operation. mode means, and second ignition mode means for performing a second ignition mode in response to a control signal for reducing the energization time of the ignition coil, and when the operation mode determining means determines that the engine is starting, the An ignition timing control device for an internal combustion engine, characterized in that the second ignition mode means controls the ignition timing only when a battery voltage is detected by a sensor to be equal to or higher than a predetermined voltage.