JP3126844B2 - Internal combustion engine ignition control device - 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 control device for an internal combustion engine that performs ignition timing at the time of cranking by bypass switching control based on a reference position signal. The present invention relates to an internal combustion engine ignition control device that is not erroneously controlled.

[0002]

2. Description of the Related Art In general, in an internal combustion engine which is rotationally driven by a plurality of cylinders via a crankshaft, in order to determine the ignition timing (energization and ignition timing of an ignition coil) of each cylinder, the rotation of the internal combustion engine is performed. Synchronized reference position signals and operating conditions from various sensors are used.

Usually, an angle detecting means for generating a reference position signal is provided on a crankshaft or a camshaft of an internal combustion engine so that rising and falling edges of the reference position signal indicate a predetermined crank angle (rotation angle of a crankshaft). Is provided.

[0004] Further, at the time of start-up (cranking), for the period of the reference position signal is unsuitable as unstable control reference, the bypass control of the ignition timing based on the rising and falling edges of the reference position signal Done. That is, the energization start timing and the ignition timing are determined by the first and second reference crank angles, respectively.

FIG. 4 is a functional block diagram showing a conventional internal combustion engine ignition control device. In the figure, reference numeral 1 denotes a known angle detecting means provided on, for example, a cam shaft of an internal combustion engine, and includes, for example, a rotary plate having a slit and a photocoupler opposed to the slit. , A pulse-shaped reference position signal SGT corresponding to the predetermined crank angle (first and second reference positions) is generated.

Normally, the first reference crank angle corresponding to the rising edge of the reference position signal SGT is B75 ° (75 ° before the top dead center), and the second reference crank angle corresponding to the falling edge of the reference position signal SGT. Is set to B5 °. The reference position serving as a reference for timer control of the ignition timing such as the ignition timing is set to, for example, B75 ° (75 ° before the top dead center) or B5 °.

Reference numeral 2 denotes various sensors for detecting an operating state D such as an inflow air amount (throttle opening) indicating an engine load, a rotation speed, and an intake air temperature. Reference numeral 20 denotes a start switch for generating a start signal C at the time of starting, that is, cranking. It is.

3 is an ECU comprising a microcomputer
An ignition timing control means 31 for calculating a map of ignition timing (energization timing and ignition timing) for each cylinder based on the reference position signal SGT and the operating state D; an input interface 32 for receiving a start signal C; A bypass switching means 33 for switching the ignition timing to an ignition timing based on the reference position signal SGT in response to C; and an output interface 34 for outputting an ignition timing signal IB indicating energization and cutoff via the bypass switching means 33. I have.

The bypass switching means 33 has a first input terminal 33a connected to an output terminal of the ignition timing control means 31.
And a second input terminal 33 to which the reference position signal SGT is applied.
b, and an output terminal 33c selectively connected to the first or second input terminal 33a or 33b. During the steady operation control, the first input terminal 33a is selected and the start signal C is input. The second input terminal 33b is selected only when

Reference numeral 4 denotes a power transistor to which the ignition timing signal IB is applied to the base, 5 denotes an ignition coil having a primary winding 5a connected to the collector of the power transistor 4, and 6 denotes a secondary winding 5b of the ignition coil 5. It is a spark plug connected to sequentially burn the air-fuel mixture in each cylinder.

FIG. 5 is a waveform diagram for explaining the operation of the conventional device, and shows a reference position signal SGT, a coil current i flowing through the primary winding 5a, and a starting signal C, respectively. In the reference position signal SGT, B75 ° is the first reference crank angle,
B5 ° is a second reference crank angle.

The coil current i is determined by the ignition timing signal IB
The power is turned on and off by the power transistor 4, and the power is turned on and off.
A high voltage is generated to discharge the spark plug 6.

Next, the operation of the conventional internal combustion engine ignition control device will be described with reference to FIGS. During the steady operation control, the output terminal of the bypass switching means 33
33c is connected to the first input terminal 33a, and the ignition timing control means 3 outputs an ignition timing signal IB output from the ignition timing control means 31.

At this time, the ignition timing control means 31
Based on the first or second reference crank angle B75 ° or B5 °, an optimum ignition timing according to the operating state D is obtained by map calculation, and the timer control time from the reference position to the energization start timing and the ignition timing is ignited. Output as a timing signal IB.

On the other hand, at the time of starting the internal combustion engine, a start signal C is generated by operating the start switch 20, and the start signal C is generated.
3 is input. As a result, the output terminal 33c of the bypass switching means 33 is switched and connected to the second input terminal 33b, the reference position signal SGT is output as the ignition timing signal IB, and the cranking state is set. Therefore, the ignition coil 5
The ignition plug 6 is provided with a reference position signal SG from the angle detecting means 1 having a hardware configuration without the intervention of the ECU 3.
Bypass control is performed by T.

That is, the energization of the coil current i is started at the first reference crank angle B75 °, and the second reference crank angle B5 °
To cut off the coil current i, discharge the spark plug 6, and burn the cylinder whose ignition is to be controlled. In the cylinder of the ignition cycle, when the power transistor 4 is cut off by the ignition timing signal IB, a high negative voltage is applied to the ignition plug 6 connected to the secondary winding 5b, and the electrode of the ignition plug 6 A discharge is generated between the cylinders and the mixture in the cylinder is ignited.

However, if the driver mistakenly operates the start switch 20 during the steady operation under the control of the ECU 3, the ignition timing may be controlled at an abnormal timing. For example, as shown in FIG. 5, when the energization start timing of the coil current i is controlled to be more advanced than the first reference crank angle B75 °, the ignition timing calculated by the ECU 3 is usually
The first reference crank angle B75 ° and the second reference crank angle B
It is set between 5 °.

At this time, if the start signal C is generated at time to, the control operation of the ECU 3 stops, and the ignition timing is switched to bypass control. That is, the bypass switching means 33 is connected from the first input terminal 33a to the second input terminal 33a.
Switching to 33b is immediately selected, and the ignition timing based on the reference position signal SGT is output as the ignition timing signal IB.

Therefore, the coil current i starts to flow at the first reference crank angle B75 °, and the second reference crank angle B5
However, since the reference position signal SGT is at the L level immediately after the bypass switching operation at the time to, it is immediately shut off as shown in FIG.

For this reason, the ignition is performed at a timing on the advanced side which is completely different from the ignition timing calculated by the ECU 3, thereby causing troubles such as damage to the internal combustion engine.

[0021]

As described above, the conventional ignition control device for the internal combustion engine immediately switches the ignition timing signal IB to the bypass control in response to the start signal C from the start switch 20. If the start switch 20 is erroneously operated during the operation control, the ignition timing is also erroneously controlled, and there is a problem that the internal combustion engine may be damaged.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and an internal combustion engine ignition control device that does not erroneously control the ignition timing even if the start switch is erroneously operated during the steady operation control. The purpose is to gain.

[0023]

An internal combustion engine ignition control apparatus according to the present invention includes a plurality of cylinders for driving an internal combustion engine to rotate, an ignition coil for sequentially burning an air-fuel mixture in each cylinder, and Angle detection means for generating reference position signals indicating the first and second reference crank angles for each cylinder, various sensors for detecting the operating state of the internal combustion engine, and a start switch for generating a start signal indicating the time of cranking; An ignition timing control means for setting an ignition timing corresponding to the ignition timing based on the reference position signal and the operating state, and switching the ignition timing to an ignition timing based on the reference position signal in response to a start signal. And bypass switching means, wherein the first and second reference crank angles are:
An internal combustion engine control device corresponding to a start time of energization of an ignition coil and an ignition timing of each cylinder at the time of cranking, wherein the start time of energization of the ignition coil is controlled to be more advanced than a first reference crank angle. In this case, a pulse generation means for generating a switching prohibition pulse over at least a period from the energization start timing to at least the first reference crank angle, and a switching prohibition for prohibiting the input of a start signal to the bypass switching means in response to the switching prohibition pulse Means.

[0024]

According to the present invention, when the energization start timing is controlled to be more advanced than the first reference crank angle,
The control state of the ECU is enabled by the switching prohibition pulse from the energization start timing to the first reference crank angle, and the control is switched to bypass control by the start signal after the first reference crank angle.

[0025]

【Example】

Embodiment 1 FIG. Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a functional block diagram showing a first embodiment of the present invention, in which 1, 2, 20, 32 to 34, 4 to 6, SGT, C,
D, i and IB are the same as described above. Also, 3A and
31A corresponds to the ECU 3 and the ignition timing control means 31, respectively.

In this case, the ignition timing control means 31A
Outputs an energization start signal IB 'corresponding to the energization start timing of the ignition timing in addition to the ignition timing signal IB. The ECU 3A includes the following components 35
And 36.

Numeral 35 is a pulse generator for generating a switching prohibition pulse P in response to the energization start signal IB 'and the reference position signal SGT. The energization start signal IB' is applied to the set input terminal S, and the reference position signal SGT Is applied to the reset input terminal R, and when the energization start timing of the ignition coil 5 is controlled to be more advanced than the first reference crank angle B75 °, the first reference crank angle An H level switching prohibition pulse P is generated up to B75 °.

The switching prohibition pulse P is set to a high level during the period from the start of energization to at least the first reference crank angle B75 °.
The fall of the switching prohibition pulse P may be set between the first reference crank angle B75 ° and before and before the second reference crank angle B5 °.

Reference numeral 36 denotes a switching prohibiting means for prohibiting the input of the start signal C to the bypass switching means 33 in response to the switching prohibiting pulse P. For example, the switching prohibiting means P is opened (turned off) only while the switching prohibiting pulse P is at the H level. A normally closed (ON) switch.

Next, the first embodiment of the present invention shown in FIG. 1 will be described with reference to the flowchart of FIG. 2 and the waveform diagram of FIG.
Will be described. As described above, the ignition timing control means 31A in the ECU 3A calculates an energization start timing and an ignition timing based on the reference position signal SGT and the operating state D, and generates an ignition timing signal IB. This ignition timing signal IB is applied to the power transistor 4 via the bypass switching means 33 and the primary winding of the ignition coil 5
Apply coil current to 5a.

On the other hand, the pulse generator 35 takes in the energization start signal IB 'from the ignition timing control means 31A from the set input terminal S and takes in the reference position signal SGT from the angle detection means 1 from the reset input terminal R. Step 2 is executed.

First, it is determined whether or not the reference position signal SGT is at the L level (step S1). If it is determined that the reference position signal SGT is at the H level (NO), the switching flag F is reset to F = 0 (step S2). ), Return. Therefore, the switching prohibition pulse P remains at the L level, and the switching prohibiting means 36 maintains the closed (on) state.

In step S1, the reference position signal S
If it is determined that the GT is at the L level (YES), it is determined whether or not the power supply is in the energized state (step S3). If it is determined that the energization of the coil current i has not been started (NO), the routine returns and the energization start (YE
If determined as S), the switching flag F is set and F = 1
(Step S4), and returns.

Thus, when the energization start signal IB 'is input while the reference position signal SGT is at the L level, the pulse generator 35 sets the switching prohibition pulse P to the H level and opens the switching prohibiting means 36 (off). ).

Therefore, while the switching inhibition pulse P is at the H level, even if the start switch 20 is operated and the start signal C is generated, the start signal C is not applied to the bypass switching means 33.
The switching to the bypass control is not performed, and the ignition timing is continuously controlled by the ECU 3A. The switching inhibition pulse P remains at the H level until the reference position signal SGT is determined to be at the H level (NO) in step S1 and the switching flag F is reset (step S2).

Therefore, as shown in FIG. 3, even if the start signal C is generated at time to, the coil current i is not interrupted as indicated by the dashed line, and the switching inhibition pulse P causes the first reference crank. The ECU 3A continues to be energized under control until the angle B 75 °. Thereafter, when the switching prohibiting pulse P becomes L level at the first reference crank angle B75 °, the switching prohibiting means 36 is closed (turned on), the start signal C is applied to the bypass switching means 33, and the ignition timing is changed to the reference position. Signal SG
The control is switched to the bypass control by T.

Accordingly, the coil current i continues to be supplied from the start of supply of electricity by the ECU 3A to the second reference crank angle B5 °. At this time, the second reference crank angle B5 °
Is the ignition timing at the time of cranking, so that no problem occurs even if the ignition timing is shifted from the ignition timing calculated by the ECU 3A.

As described above, during the steady operation control, the start signal C
Is generated, the software control state by the ECU 3A is continued until the first reference crank angle B75 ° by the switching prohibition pulse P, and then the state is switched to the hardware control state at the time of cranking. The ignition timing is not controlled, and damage to the internal combustion engine can be prevented.

Further, since it can be constituted by the simple pulse generator 35 and the switching prohibiting means 36, the load on the ECU 3A is small and the cost is not particularly increased.

[0040]

As described above, according to the present invention, a plurality of cylinders for rotationally driving the internal combustion engine, an ignition coil for sequentially burning the air-fuel mixture in each cylinder, and a first cylinder for each cylinder are provided. Angle detection means for generating a reference position signal indicating a second reference crank angle, various sensors for detecting an operation state of the internal combustion engine, a start switch for generating a start signal indicating a cranking time, a reference position signal, Ignition timing control means for setting an ignition timing corresponding to the energization timing and the ignition timing of the ignition coil based on the operating state; and bypass switching means for switching the ignition timing to an ignition timing based on the reference position signal in response to a start signal. Prepared, first
And the second reference crank angle corresponds to an ignition coil energization start timing and an ignition timing of each cylinder at the time of cranking, wherein the ignition coil energization start timing is greater than the first reference crank angle. A pulse generating means for generating a switching prohibition pulse over a period from the energization start timing to at least the first reference crank angle, and a response to the switching prohibition pulse to control the bypass switching means. A switching prohibiting means for prohibiting the input of a start signal, enabling a steady operation control state by a switching prohibiting pulse from the energization start timing to the first reference crank angle, and bypassing by the start signal after the first reference crank angle Control is switched to the internal combustion which does not erroneously control the ignition timing even if the start switch is erroneously operated during the steady operation control. The effect of related ignition control device is obtained.

[Brief description of the drawings]

FIG. 1 is a functional block diagram showing a first embodiment of the present invention.

FIG. 2 is a flowchart for explaining the operation of the pulse generating means according to the first embodiment of the present invention.

FIG. 3 is a waveform chart for explaining the operation of the first embodiment of the present invention.

FIG. 4 is a functional block diagram showing a conventional internal combustion engine ignition control device.

FIG. 5 is a waveform diagram for explaining the operation of a conventional internal combustion engine ignition control device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Angle detection means 2 Various sensors 20 Start switch 31A Ignition timing control means 33 Bypass switching means 35 Pulse generator 36 Switching prohibition means 5 Ignition coil B75 ° First reference crank angle B5 ° Second reference crank angle C Start signal D Operating state IB Ignition timing signal IB 'Energization start signal P Switching inhibition pulse SGT Reference position signal

Claims (1)

(57) [Claims] A plurality of cylinders for rotationally driving an internal combustion engine; an ignition coil for sequentially burning an air-fuel mixture in each of the cylinders; and first and second reference crank angles for each of the cylinders. Angle detecting means for generating a reference position signal indicating the operation state, various sensors for detecting the operation state of the internal combustion engine, a start switch for generating a start signal indicating the time of cranking, based on the reference position signal and the operation state. Ignition timing control means for setting an ignition timing corresponding to an energization timing and an ignition timing of the ignition coil; andbypass switching means for switching the ignition timing to an ignition timing based on the reference position signal in response to the start signal. The first and second reference crank angles are determined based on the start timing of energization of the ignition coil and the ignition of each of the cylinders during the cranking. The energization start timing of the ignition coil is controlled to be more advanced than the first reference crank angle, at least the first reference crank from the energization start time. A pulse generating means for generating a switching prohibition pulse until the corner, and a switching prohibition means for prohibiting the input of the start signal to the bypass switching means in response to the switching prohibition pulse. Internal combustion engine ignition control device.